Free-Piston-Engines.com

Building a web site dedicated to Free Piston Engine technology.

This website is specific to Free Piston Engines that use internal combustion technology.

Research & Development
Links to Technical papers, Thesis, U.S. Patents, Web sites, etc.

If you know of any links that may be added, contact
info@free-piston-engines.com

Free Piston Generator Set & Combustion Research

Free Piston Pump

Free Piston Hydraulic Pump

Free Piston Compressor

OTHER Free Piston Engine Uses

The Free Piston Engine offers a leap over conventional engine technology regarding near zero
Emissions, Less Fuel Consumption, Less Number of Parts, Less Weight, Less Cost and Less Maintenance.

In the early 1990’s interest developed in the Free Piston Linear Engine as a way to
produce Electric power using internal combustion, before that the Free Piston
Engine was investigated for use in Pumps, Hydraulic Pumps, Gas Turbines and Air
Compressors.

Today, a great amount of work around the world is being accomplished on
Free Piston Linear Engines for use in Hybrid Electric Vehicles, each showing advantages
over conventional engine technology. The links below bring those works
to a categorized and time relevant format.

Who will bring this remarkable technology to market first and in what form remains to be seen. 
These are exciting times,
Good Luck!

Free piston engine updates 8-17-2017

Free Piston Electric Power Generator Set & Combustion Research

Existing state of art of free-piston engines
http://agronomy.emu.ee/wp-content/uploads/2017/05/Vol15SP1_Raide.pdf

Disturbance analysis of a free-piston engine generator using a validated fast-response numerical model
http://www.sciencedirect.com/science/article/pii/S0306261916314842

Free Piston Engine as Efficient as Fuel Cells
http://thekneeslider.com/free-piston-engine-as-efficient-as-fuel-cells/

Free-Piston 4th Generation Engine Range Extender
https://www.irjet.net/archives/V4/i3/IRJET-V4I3632.pdf

A Decoupled Design Parameter Analysis for Free-Piston Engine Generators
www.mdpi.com/1996-1073/10/4/486/pdf

Parametric study on the starting of a free-piston engine alternator
http://journals.sagepub.com/doi/abs/10.1177/1468087417712161

A Decoupled Design Parameter Analysis for Free-Piston Engine Generators
www.mdpi.com/1996-1073/10/4/486/pdf

Transient motion control for a free-piston engine
http://journals.sagepub.com/doi/abs/10.1177/0954407016684739

Trajectory-based combustion control for renewable fuels in free piston engines
https://experts.umn.edu/en/publications/trajectory-based-combustion-control-for-renewable-fuels-in-free-p

Free-Piston 4th Generation Engine Range Extender
https://www.irjet.net/archives/V4/i3/IRJET-V4I3632.pdf

VEHICLE HYBRID FREE-PISTON ENGINE-GENERATOR
http://tf.llu.lv/conference/proceedings2017/Papers/N020.pdf

Free-Piston Isolated-Scavenge for 2-Stroke Opposed-Piston Engine
https://contest.techbriefs.com/2017/entries/automotive-transportation/7917

Tribological characteristics of piston rings in a single-piston hydraulic free-piston engine
http://www.emeraldinsight.com/doi/abs/10.1108/ILT-01-2015-0011

A model-based control design approach for linear free-piston engines
http://sro.sussex.ac.uk/68140/

Theoretical Evaluation of the Maximum Work of Free-Piston Engine Generators
http://adsabs.harvard.edu/abs/2017JNET...42...31K

High-efficiency linear combustion engine   Etagen Inc.
http://www.google.com/patents/US9567898

 

2016

Revolutionary Israeli Car Engine: 1 Cylinder, 1 Piston, 86 Horsepower, Double the Efficiency
http://www.jewishpress.com/news/revolutionary-israeli-car-engine-1-cylinder-1-piston-86-horsepower-double-the-efficiency/2016/01/24/
also
http://www.aquariusengines.com/
also
https://tallbloke.wordpress.com/2016/10/29/super-efficient-israeli-engine-bids-to-power-car-revolution/

Peugeot Investigating Innovative Range Extender Engine
http://gas2.org/2016/07/16/peugeot-investigating-innovative-range-extender-engine/

Free-piston Engine Range Extender Technology
https://www.youtube.com/watch?v=u4b0_6byuFU

Toyota developing free piston engine linear generator for hybrid cars Fox News
https://www.youtube.com/watch?v=iBwIMl917is

This startup is trying to reinvent the piston engine
https://www.youtube.com/watch?v=ZZZLPraJVd0

Israel firm wants super-efficient engine to power car revolution
https://phys.org/news/2016-10-israel-firm-super-efficient-power-car.html

Libertine: Free piston engine technology
https://www.youtube.com/watch?v=nDKjrumfspo

Introduction to Libertine's Linear Power Systems - CAD
https://www.youtube.com/watch?v=GC-i1Oerap0

PSA evaluating Aquarius Engines’ free-piston linear generator for range-extender
http://www.greencarcongress.com/2016/07/20160721-aquarius.html

Piston motion control of a free-piston engine generator: A new approach using cascade control
http://www.sciencedirect.com/science/article/pii/S0306261916310224

Free Piston Engine Linear Generator "FPEG"  Toyota
http://www.tytlabs.com/tech/fpeg/

Toyota R&D continues work on free piston linear generators for EVs; novel resonant pendulum control method
http://www.greencarcongress.com/2016/05/20160506-toyotafpeg.html

Toyota R&D team improves free piston linear generators
https://chargedevs.com/newswire/toyota-rd-team-improves-free-piston-linear-generators/

Development of Free Piston Engine Linear Generator System Part3 -Novel Control Method of Linear Generator for to Improve Efficiency and Stability Toyota
http://papers.sae.org/2016-01-0685/

Experimental Evaluation of a Prototype Free Piston Engine - Linear Alternator (FPLA) System
http://papers.sae.org/2016-01-0677/

Study on the Use of Springs in a Dual Free Piston Engine Alternator
http://papers.sae.org/2016-01-2233/

Resonance of a Spring Opposed Free Piston Engine Device
http://papers.sae.org/2016-01-0568/

Modeling and Simulation of a Free-Piston Engine with Electrical Generator Using HCCI Combustion
http://adsabs.harvard.edu/abs/2016PhDT........84A

Comparison between free piston and conventional internal combustion engine: A REVIEW
http://www.ijritcc.org/download/conferences/ICMTEST_2016/ICMTEST_2016_Track/1461905967_28-04-2016.pdf

Free Piston Engine Technology Video  SR Technology Innovations
http://www.sr-technology.eu/?p=88

TWO-STROKE DIRECT FUEL INJECT FREE PISTON GENERATOR FROM THEORY TO PRACTICE
http://www.arpnjournals.org/jeas/research_papers/rp_2016/jeas_1216_5416.pdf

A two stroke free piston engine’s performance and exhaust emission using artificial neural networks
https://link.springer.com/article/10.1007/s12206-016-0946-3

TWO-STROKE DIRECT FUEL INJECT FREE PISTON GENERATOR FROM THEORY TO PRACTICE
http://www.arpnjournals.org/jeas/research_papers/rp_2016/jeas_1216_5416.pdf

Free-Piston Linear Generator and the Development of a Solid Lubrication System
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2590043

Piston motion control of a free-piston engine generator: A new approach using cascade control
http://www.sciencedirect.com/science/article/pii/S0306261916310224

Design and simulation of a two- or four-stroke free-piston engine generator for range extender applications
http://www.sciencedirect.com/science/article/pii/S0196890415011723

Modeling and Simulation of a Free-Piston Engine with Electrical Generator Using HCCI Combustion
http://adsabs.harvard.edu/abs/2016PhDT........84A

A fast response free-piston engine generator numerical model for control applications
http://econpapers.repec.org/article/eeeappene/v_3a162_3ay_3a2016_3ai_3ac_3ap_3a321-329.htm

Development and Experimental Investigation of a Two-Stroke Opposed-Piston Free-Piston Engine
http://elib.dlr.de/108927/1/__Stfkfs01_group_41314-AEW_04%20%C3%96ffentlichkeitsarbeit_Ver%C3%B6ffentlichungen_2016_SETC%20Paper%20HomfreeII%20mit%20FKFS_Paper%20%28downloaded%29_2016-32-0046.pdf

 

2015

 

Why ‘Free Piston’ engines could power your next plug-in hybrid
https://www.digitaltrends.com/cars/road-rave-free-piston-engines-power-next-plug-hybrid/amp/

Free-Piston Engines: A Possible Route to Hybrid-Electric Vehicles  Sandia Labs - DOE
http://crf.sandia.gov/free-piston-engines-a-possible-route-to-hybrid-electric-vehicles/

TURBINE-COMPOUND FREE-PISTON LINEAR ALTERNATOR ENGINE
Free Piston Combustion Engine Design Analysis and Challenges
http://papers.sae.org/2015-32-0768/

Semi-analytical modelling of a hydraulic free-piston engine
http://econpapers.repec.org/article/eeeappene/v_3a120_3ay_3a2014_3ai_3ac_3ap_3a75-84.htm

Stable Operation and Electricity Generating Characteristics of a Single-Cylinder Free Piston Engine Linear Generator: Simulation and Experiments
http://www.mdpi.com/1996-1073/8/2/765

Precise piston trajectory control for a free piston engine
https://www.scopus.com/record/display.uri?eid=2-s2.0-84908669864&origin=inward&txGid=4a42b38d2c39da54ca3e5cc9ab283fc0

Approach to Electromagnetic Control of the Extreme Positions of a Piston in a Free Piston Generator
Download this PDF file - Canadian Center of Science and Libertine LPE free piston technology targeting power generation, waste-heat recovery and range-extended EV applications; feasibility study with PETRONAS
http://www.greencarcongress.com/2015/02/20150219-libertine.html

Simulation Study of Hydraulic Differential Drive Free-piston Engine
http://papers.sae.org/2015-01-1300/

Design and Simulation of Opposed-Piston Four-Stroke Free-Piston Linear Generator
http://papers.sae.org/2015-01-1277/

 Stable Operation and Electricity Generating Characteristics of a Single-Cylinder Free Piston Engine Linear Generator: Simulation and Experiments
PDF Full-text - MDPI.com

Stable Operation and Electricity Generating Characteristics of a Single-Cylinder Free Piston Engine Linear Generator: Simulation and Experiments
http://www.mdpi.com/1996-1073/8/2/765

Modeling of piston trajectory-based HCCI combustion enabled by a free piston engine
http://econpapers.repec.org/article/eeeappene/v_3a139_3ay_3a2015_3ai_3ac_3ap_3a313-326.htm

Novel technology aims to enable free piston engine developmentLibertine
http://www.engineeringspecifier.com/around-the-industry/iot-sensors-set-to-drive-printed-electronics-gold-rush

Breakthrough in engine efficiency wins Cleantech Innovate 2015
http://www.cleantechinnovate.com/uncategorized/breakthrough-in-engine-efficiency-wins-cleantech-innovate-2015/

Parameters matching requirements for diesel free piston linear alternator start-up
http://www.researchgate.net/publication/274250936_Parameters_matching_requirements_for_diesel_free_piston_linear_alternator_start-up

The world’s first technology forum for linear power systems technology researchers and application developers  September 7, 2015
http://www.linearpower.org/

Toyota Central R&D developing free piston engine linear generator
http://otmur.com/toyota/toyota-central-rd-developing-free-piston-engine-linear-generator.html/

Development and validation of a free-piston engine generator numerical model (2015)
http://www.sciencedirect.com/science/article/pii/S0196890414010231

Toyota Ditches Crankshaft In Their New Free Piston Engine Linear Generator (FPEG)
http://wonderfulengineering.com/toyota-ditches-crankshaft-in-their-new-free-piston-engine-linear-generator-fpeg/

Investigation of Control Method for Starting of Linear Internal Combustion Engine-Linear Generator Integrated System
http://papers.sae.org/2015-01-1729/

Piston motion control of a free-piston engine generator: A new approach using cascade control FPEG
http://eprint.ncl.ac.uk/file_store/production/226997/71A47F25-8F1C-4462-9D3C-C92FC7437460.pdf

Recent commercial free-piston engine developments for automotive applications
https://www.researchgate.net/publication/278323339_Recent_commercial_free-piston_engine_developments_for_automotive_applications

A New Approach to Reduce Engine-Out Emissions Enabled by Trajectory-Based Combustion Control
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2481872

Linear free piston combustion engine with indirect work extraction via gas linkage  Etagen Inc.
http://www.google.com/patents/US8997699

Linear free piston combustion engine with indirect work extraction via gas linkage Etagen Inc.
http://www.google.com/patents/US8997699

Free-piston internal combustion engine
http://www.google.com/patents/US9032918

 

2014

 

No crankshaft, no problem: Toyota's free piston engine is brilliant
http://www.roadandtrack.com/go/out-of-turn-toyota-engine

Youtube Toyota developing free piston engine linear generator for hybrid cars Fox News
http://www.youtube.com/watch?v=iBwIMl917is

Recent Commercial Free-Piston Engine Developments for Automotive Applications
http://umpir.ump.edu.my/7031/

Fundamental Analysis of Spring-Varied, Free Piston, Otto Engine Device
http://papers.sae.org/2014-01-1099/

Optimal motion trajectory for the four-stroke free-piston engine with irreversible Miller cycle via a Gauss pseudospectral method
http://www.degruyter.com/view/j/jnet.2014.39.issue-3/jnet-2014-0003/jnet-2014-0003.xml

Free-Piston Engines: A Possible Route to Hybrid-Electric Vehicles
http://crf.sandia.gov/free-piston-engines-a-possible-route-to-hybrid-electric-vehicles/

The Effect of Cylinder Clearance on Output Work of ORC-FP used in Waste Energy Recovery
http://papers.sae.org/2014-01-2563/

Fundamental Explorations of Spring-Varied, Free Piston Linear Engine Devices
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2022933

Precise piston trajectory control for a free piston engine
http://www.sciencedirect.com/science/article/pii/S0967066114002354

Investigation of the starting process of free-piston engine generator by mechanical resonance

Investigation of the starting process of free-piston engine ...

 

Tribological Characteristics of Piston Ring in a Free-piston Engine for Linear Generator
http://www.sciencedirect.com/science/article/pii/S1876610214028380

High-efficiency linear combustion engine   Etagen Inc.
http://www.google.com/patents/US8662029

Free piston engine  Libertine Fpe Ltd.
http://www.google.com/patents/US8794198

Design of future concepts and variants of The Free Piston Linear Generator - Toyota
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6844029&sortType%3Dasc_p_Sequence%26filter%3DAND(p_IS_Number%3A6843992)

Development of Free Piston Engine Linear Generator System Part 2 - Investigation of Control System for Generator  - Toyota
http://papers.sae.org/2014-01-1193/

Development of Free Piston Engine Linear Generator System Part 1 - Investigation of Fundamental Characteristics – Toyota
http://papers.sae.org/2014-01-1203/

Green Car Congress 2014 Toyota Central R&D developing free-piston engine linear generator; envisioning multi-FPEG units for electric drive vehicles
http://www.greencarcongress.com/2014/04/20140422-fpeg.html

TURBINE-COMPOUND FREE-PISTON LINEAR ALTERNATOR ENGINE
http://deepblue.lib.umich.edu/bitstream/handle/2027.42/107140/brandlee_1.pdf?sequence=1&isAllowed=y

Optimal motion trajectory for the four-stroke free-piston engine with irreversible Miller cycle via a Gauss pseudospectral method
http://www.degruyter.com/view/j/jnet.2014.39.issue-3/jnet-2014-0003/jnet-2014-0003.xml?format=INT

Simulation Study of SI-HCCI Transition in a Two-Stroke Free Piston Engine Fuelled with Propane
http://papers.sae.org/2014-01-1104/

Development of Free Piston Engine Linear Generator System Part 1 - Investigation of Fundamental Characteristics
http://papers.sae.org/2014-01-1203/

Development of Free Piston Engine Linear Generator System Part 2 - Investigation of Control System for Generator
http://papers.sae.org/2014-01-1193/

Fundamental Analysis of Spring-Varied, Free Piston, Otto Engine Device
http://papers.sae.org/2014-01-1099/

Overcoming Pressure Waves to Achieve High Load HCCI Combustion
http://papers.sae.org/2014-01-1269/

Fundamental Analysis of Spring-Varied, Free Piston, Otto Engine Device
http://papers.sae.org/2014-01-1099/

Free piston engine – Libertine
http://www.google.com/patents/US8794198

Free piston linear alternator utilizing opposed pistons with spring return - GM
http://www.google.com/patents/US8714117

Opposed-piston cylinder bore constructions with solid lubrication in the top ring reversal zones – Achates Power
http://www.google.com/patents/US8851029

Methods and systems for managing a clearance gap in a piston engine - Etagen
http://www.google.com/patents/US8770090

Methods and systems for managing a clearance gap in a piston engine - Etagen
http://www.google.com/patents/US8720317

Piston engine having magnetic piston bearing - Siemens Aktiengesellschaft
http://www.google.com/patents/CA2772845C?cl=en

Opposed piston internal combustion engine and method of operation thereof
http://www.google.com/patents/US8671681

High-efficiency linear combustion engine - Etagen, Inc.
http://www.google.com/patents/US8662029

Methods and systems for managing a clearance gap in a piston engine - Etagen, Inc.
http://www.google.com/patents/US8656895

2013

Free Piston Electric Power Generator Set & Combustion Research

Opposed free piston linear alternator  GM
http://www.google.com/patents/US8616162

High-efficiency linear combustion engine   Etagen, Inc.
http://www.google.com/patents/US8402931

Free-piston IC generator developed for range-extender hybrids
http://articles.sae.org/12284/

TIME FOR A RETHINK  A free-piston IC generator has been developed for range-extended hybrids. 
Steven Ashley looks at the implications.  SAE Magazine November/December 2013
http://www.sae.org/magazines/pdf/AUTODES1213.pdf

Influence of Pressure Build-Up Time of Compression Chamber on Improving the Operation Frequency of a Single-Piston Hydraulic Free-Piston Engine
http://bit.ly/1t4cO8b

Development Approach for the Investigation of Homogeneous Charge Compression Ignition in a Free-Piston Engine
http://papers.sae.org/2013-24-0047/

Free piston linear generator in comparison to other range-extender technologies
http://elib.dlr.de/87403/1/EVS%2027_DLR_Virsik_Heron_FPLG.pdf

MAGNETIC FIELD OF TUBULAR LINEAR MACHINES WITH DUAL HALBACH ARRAY
http://www.jpier.org/PIER/pier136/18.12110302.pdf

Dynamics and Control of a Free-Piston Diesel Engine
http://bit.ly/1t4cQgr

U of M student project to create a renewable fuel engine wins $10,000 prize in Dow SISCA Challenge
http://www1.umn.edu/news/news-releases/2013/UR_CONTENT_464971.html

Opposed free piston linear alternator - GM
http://www.google.com/patents/US8616162

Free piston assembly and method for controlling a free piston assembly - Umc Universal Motor Corp
http://www.google.com/patents/US8601988

Opposed free piston linear alternator - GM
http://www.google.com/patents/US8616162

Linear generator having a fluid pressure cylinder structure
http://www.google.com/patents/US8610320

Free piston assembly and method for controlling a free piston assembly - Umc Universal Motor Corporation Gmbh
http://www.google.com/patents/US8601988

Free piston linear generator FKLG - youtube
http://www.youtube.com/watch?v=_pBPw33ceoQ

Car Engine of the Future – New Internal Combustion Engine to boost Electric Cars Range, Efficiency
http://www.youtube.com/watch?v=yV09wMXTSIc

High efficiency small power generation - Video Presentation
http://www.cleantechinnovate.com/dt_portfolio/libertine-fpe-ltd/

New internal combustion engine could boost electric cars - News
http://www.foxnews.com/leisure/2013/03/13/new-internal-combustion-engine-could-boost-electric-cars/

SAE Automotive Engineering online Magazine
http://www.sae.org/mags/aei/12284/

DLR-free-piston-linear-generator-range-extender - Magazine
http://www.gizmag.com/dlr-free-piston-linear-generator-range-extender/27736/

Germans create ‘free-piston’ multi-fuel engine that could answer EV range
DLR team develops demonstrator of free-piston linear generator as range extender for EVs; technology
transfer to Universal Motor Corp
http://www.greencarcongress.com/2013/02/dlr-20120220.html
and
http://www.freikolben.ch/37401/109964.html

Development of an opposed free-piston linear generator according to the Pescara principle
http://www.freikolben.ch/37401/235512.html

Freikolbenmotoren / Free Piston Engines
http://www.freikolben.ch/9301.html

Sandia Labs Free-Piston Engine Project 2013
http://www4.eere.energy.gov/vehiclesandfuels/resources/merit-review/sites/default/files/ace008_johnson_2013_o.pdf

The Chiron free piston electric generator
http://www.innas.com/Chiron_FPG.html

Linear Combustion Engine project at the Czech technical university
http://www.lceproject.org/en/index.php

Development Approach for the Investigation of Homogeneous Charge Compression Ignition in a Free-Piston Engine
http://papers.sae.org/2013-01-2653/

A highly efficient energy converter for a hybrid vehicle concept - focused on the linear generator of the next generation
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6521533&queryText%3DFree-piston+Generator

A high efficient energy converter with flex fuel potential
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6586916&queryText%3DFree-piston+Generator

A transverse flux permanent magnet linear generator for hybrid electric vehicles
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6563717&pageNumber%3D2%26queryText%3DFree-piston+Generator

The Free Piston Linear Generator - Development of an Innovative, Compact, Highly Efficient Range-Extender Module - DLR
http://papers.sae.org/2013-01-1727/

Design and Operational Characteristics of a Novel Floating-Stroke, Free Piston Internal Combustion Reciprocating Engine – Energy Transition Technology
http://papers.sae.org/2013-01-0284/

Effect of Injection Timing on the Operation of Hydrogen-Fuelled Free-Piston Linear Generator Engine during  starting
http://tech.jsae.or.jp/ijae/detail.aspx?pno=20134102

An Investigation into the Operating Characteristics of a Free Piston Linear Engine Using Numerical Analysis]- SAE
http://www.bookpark.ne.jp/cm/jsae/search_e.asp

Investigation of Starting Behaviour of a Free-piston Linear Generator
http://scialert.net/fulltext/?doi=jas.2012.2592.2597

Zero constraint free piston energy converter
http://www.lboro.ac.uk/departments/aae/research/groups/low-carbon-technology/project-piston-energy.html

Free piston engine considerations: concepts, cycles, combustion variability, aalternator configurations, regulation of piston movement, 
http://www.unitec.ac.nz/jmctest/free_piston_linear_alternators/?author=1

Modelling and Control of Linear Combustion Engine LCE
http://www.slideserve.com/jasmine/modelling-and-control-of-linear-combustion-engine-lce

Fuel combustion under asymmetric piston motion-Tested results
http://www.academia.edu/4083680/Fuel_combustion_under_asymmetric_piston_motion_Tested_results

Free Piston Engine Development - Unitec
http://www.unitec.ac.nz/jmctest/free_piston_linear_alternators/?author=2

High-efficiency linear combustion engine - EtaGen
http://www.google.com/patents/US8453612

High-efficiency two-piston linear combustion engine - EtaGen
http://www.google.com/patents/US8413617

High-efficiency linear combustion engine - EtaGen
http://www.google.com/patents/US8402931

Modular Auxiliary Power Unit Assembly For An Electric Vehicle - GE
http://www.google.com/patents/US8376070

Engine device
http://www.google.com/patents/US8485146

 

 2012

Development of a Free-Piston Linear Generator for use in an Extended-Range Electric Vehicle
http://elib.dlr.de/80777/1/EVS_26_Ferrari.pdf

West Virginia University Linear Engine Development
http://energy.gov/sites/prod/files/2014/03/f8/p-06_covington.pdf

Numerical and Experimental Investigation of In-Cylinder Flow in a Loop-Scavenged Two-Stroke Free Piston Engine
http://papers.sae.org/2012-32-0114/

Free Piston Four Stroke Linear Engine With Generator - youtube
http://www.youtube.com/watch?v=2SlwoBLspTQ

Greencarcongress.com 2012
http://www.greencarcongress.com/2012/11/fpla-20121125.html

Novel opposed-piston free-piston linear generator for hybrids seeks to overcome drawbacks of earlier designs
http://www.greencarcongress.com/2012/06/huang-20120606.html

FREE-PISTON ENGINE - DOE Sandia National Laboratories . Tuesday, May 15, 2012 . Project ID: ACE008
http://freepdfdb.org/pdf/free-piston-engine-energygov-department-of-energy-34355929.html

Free piston internal combustion engine
http://www.ncl.ac.uk/business/commercialisation/transfer/engineering/free-piston-internal-combustion-engine.htm

Free-CHP: free-Piston Reciprocating Joule Cycle Engine
http://research.ncl.ac.uk/pro-tem/components/pdfs/ICAE2012/Newcastle_RMikalsen.pdf

Numerical and Experimental Investigation of In-Cylinder Flow in a Loop-Scavenged Two-Stroke Free Piston
Engine - DLR
http://papers.sae.org/2012-32-0114/

A Study for Generating Power on Operating Parameters of Powerpack Utilizing Linear Engine
http://papers.sae.org/2012-32-0061/

The Effects of Spark Timing and Equivalence Ratio on Spark-Ignition Linear Engine Operation with Liquefied Petroleum Gas
http://papers.sae.org/2012-01-0424/

An Opposed-Piston Free-Piston Linear Generator Development for HEV
http://papers.sae.org/2012-01-1021/

Use of 2D and 3D finite elements in the design of novel transverse flux machines
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6387468

Design optimisation of a transverse flux, short stroke, linear generator
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6349937&pageNumber%3D2%26queryText%3DFree-piston+Generator

Oscillating generator for hybrid-electrical and electrical vehicles
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6350155&pageNumber%3D2%26queryText%3DFree-piston+Generator

Performance comparison of saturated tubular linear permanent magnet generators by simplified FEAs
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=6477463&pageNumber%3D2%26queryText%3DFree-piston+Generator

Effect of injection timing of hydrogen-fuelled free-piston linear generator engine during starting JSAE 20134102
http://tech.jsae.or.jp/ijae/download_pdf.aspx?pno=20134102

Linear Permanent Magnet Electric Generator for Free Piston Engine Applications
http://users.utcluj.ro/~szabol/Papers/ICEM2012_2.pdf

Development of a Free-Piston Linear Generator for use in an Extended-Range Electric Vehicle
http://elib.dlr.de/80777/1/EVS_26_Ferrari.pdf

Effect of Compression Ratio and Applied Voltage on Free-Piston Linear Generator Engine
http://www.waset.org/journals/ijeps/v6/v6-73.pdf

Study on Piston Motion Control Strategy of Single Piston Hydraulic Free-piston Engine
http://bit.ly/1fB8AiW

Dimensionless Parametric Analysis of Spark Ignited Free-Piston Linear Alternator
http://bit.ly/19hHfsR

Simulation Of A Two–Stroke Spark Ignition Free Piston Linear Engine Motion
http://bit.ly/1bUh1nb

Permanent Magnetic Model Design and Characteristic Analysis of the Short-stroke Free Piston Alternator
http://papers.sae.org/2012-01-1610/

Liquid Fuel Vaporization Process Built Inside 2-Stroke Piston Engines
http://papers.sae.org/2012-36-0122/

Hybrid powertrain system using free piston linear alternator engines - GM
http://www.google.com/patents/US8261860

OPPOSED FREE PISTON LINEAR ALTERNATOR - GM
http://www.google.com/patents/US20120112468

Free-piston linear alternator systems and methods - GM
ttp://www.google.com/patents/US8324745

Method to convert free-piston linear motion to rotary motion
http://www.google.com/patents/US8151744

Free Piston Engine – Libertine
http://www.google.com/patents/US20120280513

Piston – Libertine
http://www.google.com/patents/US20120255434

Combustion Management System – Libertine
http://www.google.com/patents/US20120266842

Paired-piston linear engine
http://www.google.com/patents/US8091519

Free piston engine generator – Libertine FPE
http://www.google.com/patents/WO2012080709A1?cl=en

 

2011

HiPerTEC: Toroidal, Opposed, Free Piston Engine (HT3) - youtube
http://www.youtube.com/watch?v=ARaYBPd898A&feature=endscreen&NR=1

The Operation of Free Piston Linear Generator Engine Using MOSFET and IGBT Drivers
http://scialert.net/fulltext/?doi=jas.2011.1791.1796&org=11

One-dimensional simulation of two stroke hydrogen direct injection linear generator free-piston engine
http://umpir.ump.edu.my/1714/1/Muhammad_Alliff_Rahim_(_CD_5128_).pdf

End effects in linear tubular motors and compensated position sensorless control based on pulsating voltage injection
http://core.kmi.open.ac.uk/download/pdf/11413853.pdf

A Comparative Study of Permanent Magnet Linear Alternator and Hydraulic Free Piston Engines
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1638333

A Novel Approach to Free-Piston Engine Control Using an FPGA Based Control System
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1627388

A Comparative Study of Permanent Magnet Linear Alternator and Hydraulic Free-Piston Engines
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1638333

2011 DOE Vehicle Technologies Program Annual Merit Review May 10, 2011
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2011/adv_combustion/ace008_vanblarigan_2011_o.pdf

Numerical analysis of two-stroke free piston engine operating on HCCI combustion
http://journals.ohiolink.edu/ejc/pdf.cgi/Xu_Shuaiqing.pdf?issn=03062619&issue=v88i0011&article=3712_naotfpeoohc

Compression Ignition Linear Engine Design Variable Effects
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1627441

Design of a 5 kW Tubular Permanent Magnet Linear Alternator
http://bit.ly/199YGRP

Research on a novel tubular transverse-flux permanent-magnet linear machine for free-piston energy converter
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6073432

Dynamic modeling of SI/HCCI free-piston engine generators
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5975849&queryText%3DFree-piston+Generator

Engine Terminology and Nomenclature-General
SAE Recommended Practice is applicable to all types of reciprocating engines including two-stroke cycle and free piston engines
http://standards.sae.org/j604_201108/

Opposed-piston-two-stroke-diesel-engine-a-renaissance
http://freepdfdb.org/pdf/opposed-piston-two-stroke-diesel-engine-a-renaissance-7682641.html

Research on the Magnetic Characteristic of a Novel Transverse-Flux PM Linear Machine Used for Free-Piston Energy Converter
http://bit.ly/14VSWI1

Dimensionless Parametric Analysis of Spark Ignited Free-Piston Linear Alternator
http://bit.ly/15EfxWO

FREE-PISTON INTERNAL COMBUSTION ENGINE
http://bit.ly/15EfrOZ

Free Piston Engine - Libertine
http://www.google.com/patents/US20120280513?cl=en

A piston – Libertine FPE
https://www.google.com/patents/US20120255434?cl=en

Control method for a free-piston engine using a prediction curve and a free-piston engine controlled thereby -  Enginetech
http://www.google.com/patents/WO2011068258A1?cl=en

Combustion management system – Libertine FPE
http://www.google.com/patents/WO2011077162A1?cl=en

Free piston electromagnetic engine – Invention Science Fund
http://www.google.com/patents/US8037852

Linear power generator with a reciprocating piston configuration
http://www.google.com/patents/US20110221206

 

2010

 

linear combustion engine.flv - youtube
http://www.youtube.com/watch?NR=1&v=B93n8sNsRpU&feature=endscreen

Stelzer Free Piston Engine - youtube
http://www.youtube.com/watch?v=YR5PGGKS4ys

Linear Combustion Engine - Honda
http://www.my-hondacars.com/honda-video/civic-2013/linear-combustion-engineflv-V-B93n8sNsRpU.htm

Free-piston internal combustion engine for hybrid drive device of motor vehicle, has electric linear drive and piston device with piston and rotor device - BOSCH GMBH
http://worldwide.espacenet.com/publicationDetails/biblio?CC=DE&NR=102008042169A1&KC=A1&FT=D

Simulations of Key Design Parameters and Performance Optimization for a Free-piston Engine
http://papers.sae.org/2010-01-1105/

The-control-of-a-free-piston-engine-generator-part-1- fundamental analyses
http://www.mikalsen.eu/papers/FPEcontrol1.pdf

The-control-of-a-free-piston-engine-generator-part-2-engine dynamics and piston motion control
http://www.mikalsen.eu/papers/FPEcontrol2.pdf

Parametric study of a free piston linear alternator
http://link.springer.com/article/10.1007%2Fs12239-010-0015-3

Predictive piston motion control in a free-piston internal combustion engine
http://www.sciencedirect.com/science/article/pii/S0306261909004784

Prototype testing and analysis of a novel internal combustion linear generator integrated power system
http://econpapers.repec.org/article/eeeappene/v_3a87_3ay_3a2010_3ai_3a4_3ap_3a1342-1348.htm

A Linear Magnetic-geared Free-piston Generator for Range-extended Electric Vehicles
http://union-services.com/aevs/1345-1349.pdf

Design and analysis of a novel linear transverse flux permanent magnet motor using HTS magnetic shielding
http://hub.hku.hk/bitstream/10722/129184/1/Content.pdf

Modeling of a Two-Stroke Free-Piston Engine With HCCI Combustion
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1613343

Design Optimization of Transverse Flux Linear Motor for Weight Reduction and Performance Improvement
 Using Response Surface Methodology and Genetic Algorithms
http://bit.ly/16CvUcw

Experimental Study on Hydraulic Free Piston Diesel Engine
http://papers.sae.org/2010-01-2149/

Improved Moving Coil Electric Machine for Internal Combustion Linear Generator
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5409649

Design of a linear magnetic-geared free-piston generator for series hybrid electric vehicles
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5729021&url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D5729021

Research on the electromagnetic structure and performance of a novel transverse-flux PM linear machine used for free-piston energy converter
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5481293

Free piston tubular permanent-magnet linear generator based on electromagnetic field analysis
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5535633&queryText%3DFree-piston+Generator

Calculation of a linear generator for a hybrid vehicle concept
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5607780&queryText%3DFree-piston+Generator

Modeling and simulation of a moving-coil linear generator
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5716156&pageNumber%3D2%26queryText%3DFree-piston+Generator

Energy Converter - Volvo Car Corporation
http://www.google.com/patents/US7845317

Free piston electromagnetic engine – The Invention Fund
http://www.google.com/patents/US7777357

Method and system for controlling a free-piston energy converter - Volvo
http://www.google.com/patents/US7721686

Linear generator
http://www.google.com/patents/US20100277012

Free-piston engine having variable stroke and method for operating a free-piston engine – UMC Universal Motor Corp
http://www.google.com/patents/WO2010046120A1?cl=en

Free piston assembly and method for controlling a free piston assembly - UMC Universal Motor Corp
http://www.google.com/patents/US20100162998

Deformable chamber-based homogeneous charge combustion ignition (HCCI) engine and generator
http://www.google.com/patents/US7775184

Free piston device with electrically driven linear actuator
http://www.google.com/patents/EP1398863B1?cl=en

 

2009

 

Video – Galileo Prototype –2
http://www.galileo-fpe.com/assets/multimedia/galileo-fpe.wmv

DOE Sandia Labs Technical Paper FREE PISTON GEN SET
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2009/advanced_combustion/ace_08_vanblarigan.pdf

The design and simulation of a two-stroke free-piston compression ignition engine for electrical power generation - Innas
http://www.mikalsen.eu/papers/FPEsimulation.pdf

The performance characteristics of a hydrogen-fuelled free piston internal combustion engine and linear generator system
http://ijlct.oxfordjournals.org/content/4/1/36.abstract

Performance simulation of a spark ignited free-piston engine generator
http://www.mikalsen.eu/papers/FPEsparkIgnition.pdf

Coupled dynamic–multidimensional modelling of free-piston engine combustion.
http://www.mikalsen.eu/papers/FPEcoupledSolver.pdf

Modeling and Experimental Characterization of a Permanent Magnet Linear Alternator for Free-Piston Engine Applications – Sandia Labs
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1647880

A review of free-piston engine history and applications.
http://www.mikalsen.eu/papers/FPEreview.pdf

Coupled dynamic–multidimensional modeling of free-piston engine Combustion
http://www.mikalsen.eu/papers/FPEcoupledSolver.pdf

Advanced Combustion/Modeling and Analysis Toward HCCI/PCCI in a 60% Efficient Free-Piston Engine – DOE
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2009/poster1/deer09_fitzgerald.pdf

Modeling and Control of a High Pressure Combined Air/Fuel Injection System
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1648355

MODELING OF TWO STROKE, DUAL CYLINDER FREE PISTON LINEAR GENERATOR ENGINE
http://www.thedigilib.com/doc/247874-modeling-of-two-stroke-dual-cylinder-free-piston-linear-generator-engine

Investigation of linear generator starting modes by mechanical resonance and rectangular current commutation
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5075241&queryText%3DFree-piston+Generator

A computational study of free-piston diesel engine combustion
http://www.mikalsen.eu/papers/FPEdieselCFD.pdf

Dynamic and thermodynamic analysis of two-stroke, dual cylinder, linear combustion engine
http://eprints.utp.edu.my/4926/

Energy Converter Having Pistons With Internal Gas Passages
http://www.google.com/patents/US20090308345

Power generating system - Aerodyne Research
http://www.google.com/patents/US7485977

Hybrid drive
http://www.google.com/patents/US20090107744

 

2008

Free Piston Electric Power Generator Set & Combustion Research

Free Piston Engine as Efficient as Fuel Cells
http://thekneeslider.com/free-piston-engine-as-efficient-as-fuel-cells/

YOUTUBE VIDEO OF The Linear Combustion Engine
http://www.youtube.com/watch?v=pX3oAjnYZgc

High-Efficiency Generators for Hybrid Vehicles - Magazine
http://www.technologyreview.com/news/410914/high-efficiency-generators-for-hybrid-vehicles/?nlid=1374

DOE FREE PISTON GEN SET - DOE - SANDIA LABS
http://www.cleanmpg.com/forums/printthread.php?t=16278

FREE PISTON GEN SET FP3
http://www.freepistonpower.com/

Modeling a Free-Piston Engine Genset for Hybrid Applications 
http://www.greencarcongress.com/2008/09/modeling-a-free.html

FY 2008 DOE Vehicle Technologies Office Annual Merit Review
http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/2008_merit_review.html

Modeling and Simulation of a Hydraulic Free Piston Diesel Engine
http://papers.sae.org/2008-01-1528/

Simulation of a Two-Stroke Free-Piston Engine for Electrical Power Generation
http://pubs.acs.org/doi/pdf/10.1021/ef800217k

SIMULATION OF FOUR STROKE FREE PISTON DIESEL ENGINE
http://umpir.ump.edu.my/1048/1/Hafnizar_Muhamad_Shaharuddin.pdf

The fuel efficiency and exhaust gas emissions of a low heat rejection free-piston diesel engine
http://eprint.ncl.ac.uk/%2Ffile_store%2Fproduction%2F148460%2F35A33F52-1EF2-4F55-AACD-88EDA5330047.pdf

The design and simulation of a two-stroke free-piston compression ignition engine for electrical power generation
http://www.mikalsen.eu/papers/FPEsimulation.pdf

A New Type of Fuel Cell, Free Piston Engines
http://galileo-fpe.com/assets/documents/A-New-Type-of-Fuel-Cell-%20Free%20Piston-Engines-by-KG.pdf

CFD-Based Optimization of a Diesel-fueled Free Piston Engine Prototype for Conventional and HCCI Combustion
http://papers.sae.org/2008-01-2423/

MINIATURE INTERNAL COMBUSTION ENGINE-GENERATOR FOR HIGH ENERGY DENSITY PORTABLE POWER
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA504220

3D analyses of a novel Transverse Flux machine for a free piston energy converter
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4799878

Rectangular current commutation and open-loop control for starting of a free-piston linear engine-generator
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4762637&queryText%3DFree-piston+Generator

Direct power control of a permanent magnet linear generator in a free piston energy converter
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4771406&queryText%3DFree-piston+Generator

Starting of a free-piston linear engine-generator by mechanical resonance and rectangular current commutation
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4677748&queryText%3DFree-piston+Generator

DIESEL FREE PISTON GEN SET STUDY Simulation of In-cylinder Processes in a
Free Piston Engine
http://bit.ly/1bjsXfn

The design and simulation of a two-stroke free-piston compression ignition engine for electrical power generation
http://www.mikalsen.eu/papers/FPEsimulation.pdf

Performance simulation of a spark ignited free-piston engine generator.
http://www.mikalsen.eu/papers/FPEsparkIgnition.pdf

SIMULATION OF FOUR STROKE FREE PISTON DIESEL ENGINE
http://umpir.ump.edu.my/1048/1/Hafnizar_Muhamad_Shaharuddin.pdf

Simulation of a Two-Stroke Free-Piston Engine for Electrical Power Generation
http://pubs.acs.org/doi/full/10.1021/ef800217k

Zero constraint free piston energy converter
http://www.lboro.ac.uk/departments/aae/research/groups/low-carbon-technology/project-piston-energy.html

Flat-type permanent magnet linear alternator: A suitable device for a free piston linear alternator
http://link.springer.com/article/10.1631%2Fjzus.A0820224

Starting Mode Analysis of Flat-type Linear Generator for Free-Piston Engine
http://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=DHJGII_2008_v57n6_966

Engine System Having Improved Efficiency - Ford
http://www.google.com/patents/US7426910

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7383796

System and method for controlling a power generating system – Aerodyne Research
https://www.google.com/patents/US7332825

Free piston engine with linear power generator system
http://www.google.com/patents/US7318506

Four-Stroke Free Piston Engine
http://www.google.com/patents/US20080271711

 

2007

 

Investigation of a high efficient Free Piston Linear Generator with variable Stroke and variable Compression Ratio  A new Approach for Free Piston Engines
http://elib.dlr.de/49457/1/FKLG_-_WEVA_2007_Volume_1.pdf?origin=publication_detail

Linear Combustion engine as main energy unit for hybrid vehicles
http://www3.fs.cvut.cz/web/fileadmin/documents/12241-BOZEK/publikace/2007/2007_078_01.pdf

Analysis of Tubular-type Linear Generator for Free-Piston Engine
http://www.icrepq.com/icrepq07/365-Sun-Ki%20Hong.pdf

Structural Design and Porting Parameters Calculation of a Micro Piston Engine for Power Generation
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1592225

Research on a Tubular Longitudinal Flux PM Linear Generator Used for Free-Piston Energy Converter
http://bit.ly/1676ph1

Introducing Hydraulic-Electric Synergy into Hybrid Transmission Using the Free-piston Engine Technology
http://papers.sae.org/2007-01-4112/

Numerically Modeling the Dynamics of a Piston-Mounted Passive Inlet Poppet Valve
http://papers.sae.org/2007-32-0099/

Dynamic Simulation of the Transverse Flux Machine using Linear Model and Finite Element Method
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4460058

Design and Experimental Verification of a Linear Permanent Magnet Generator for a Free-Piston Energy Converter
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4207479&queryText%3DFree-piston+Generator

Starting mode analysis of tubular-type linear generator for free-piston engine with dynamic characteristics
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4412221&queryText%3DFree-piston+Generator

Control device for free piston engine and method for the same – Denso Corp
http://www.google.com/patents/US7258085

Internal combustion engine – Advanced Propulsion Technologies
http://www.google.com/patents/US7207299

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7255070

Linear-electrical-machine-for-electric-power-generation-or-motive-drive – TIAX LLC
 http://www.google.com/patents/US20070108850

Four-cylinder, four-cycle, free piston, premixed charge compression ignition, internal combustion reciprocating piston engine with a variable piston stroke
http://www.google.com/patents/US7258086

 

2006

 

Modeling a Two-Stroke, Free-Piston HCCI-Like Engine for Hybrid Applications
2006 SAE GREEN CAR CONGRESS
http://www.greencarcongress.com/2006/11/modeling_a_twos.html

Performance of a Series Hybrid Electric Vehicle with a Free-Piston Energy Converter
http://www.ee.kth.se/php/modules/publications/reports/2006/IR-EE-EME_2006_003.pdf

Linear Engine Coupled Linear Generator Starting For Hybrid Electric Vehicle Applications
http://www.icee-con.org/papers/2006/pdf/MI1-04.pdf

Analysis and control of a hybrid vehicle powered by free-piston energy converter
http://kth.diva-portal.org/smash/get/diva2:11141/FULLTEXT01.pdf

Modeling the Effect of Injection Schedule Change on Free Piston Engine Operation
http://papers.sae.org/2006-01-0449/

CONTROL OF TWO-STROKE FREE-PISTON GENERATOR
http://www3.fs.cvut.cz/web/fileadmin/documents/12241-BOZEK/publikace/2007/2007_076_01.pdf

Modeling of a Free Piston Energy Converter
http://publications.lib.chalmers.se/cpl/record/index.xsql?pubid=22421

Reciprocating flux-concentrated induction generator for free-piston generator
http://bit.ly/1bjuKRs

A Unique Starting Scheme of Linear-Engine Tubular PM Linear Generator System Using Position Feedback Controlled PWM Inverter
http://bit.ly/15Do7KS

Detent Force Reduction of a Tubular Linear Generator Using an Axial Stepped Permanent Magnet Structure
http://bit.ly/16Wz9px

In-cycle thermodynamic model of linear combustion engine
http://bit.ly/15EgluO

SIMULATION OF A TWO-STROKE SPARK IGNITION FREE PISTON LINEAR ENGINE MOTION
http://www.jurnalteknologi.utm.my/index.php/jurnalteknologi/article/view/352/342

DURABILITY ASSESMENT OF A NEW FREE PISTON SPARK IGNITION LINEAR ENGINE:  A COMPUTATIONAL APPROACH
http://www.jurnalteknologi.utm.my/index.php/jurnalteknologi/article/view/318/308

Simulation of Linear Induction Generators in Hybrid Electric Vehicle Applications
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4123564&queryText%3DFree-piston+Generator

Free-piston generator
http://worldwide.espacenet.com/publicationDetails/biblio?CC=CN&NR=1978877A&KC=A&FT=D

Apparatus for determining free piston position and an apparatus for controlling free piston position – Global Cooling
http://www.google.com/patents/US7075292

Starting a compression ignition free piston internal combustion engine having multiple cylinders  - Ford
http://www.google.com/patents/US6983724

Free-piston device with electric linear drive – Deutsches Zentrum fur Luft
http://www.google.com/patents/US7082909

Two-stroke internal combustion engine with free opposed pistons - FEV
http://www.google.com/patents/US7047916

Method for regulating the operation of a device for generating electric energy by means of a generator driven by a free-piston internal combustion engine - FEV
http://www.google.com/patents/US7116004

Free-piston device with electric linear drive - Deutsches Zentrum fur Luft
http://www.google.com/patents/US7082909

Valve system for a rapid response power conversion device – Sarcos Investments
http://www.google.com/patents/US7066116

 

2005

 

Dynamic Simulation of a Free-Piston Linear Alternator in Modelica
https://modelica.org/events/Conference2005/online_proceedings/Session5/Session5a2.pdf

Operational Strategies for a Free Piston Energy Converter
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.66.1375&rep=rep1&type=pdf

COMBUSTION MODELLING Assessing the HCCI Characteristics of n-Heptane using a Free Piston Rapid Compression Expansion Machine
http://ci.confex.com/ci/2005/techprogram/P1944.HTM

CFD Modeling of a Two-Stroke Free Piston Energy Converter using Detailed Chemistry
http://papers.sae.org/2005-24-074/

The Linear Engine in 2004
http://papers.sae.org/2005-01-2140/

Minimizing Power Pulsations in a Free Piston Energy Converter
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.65.7827&rep=rep1&type=pdf

A Proposed Hybrid Electric Power Train for Trucks
http://www.freepistonpower.com/Hybrid%20Electric%20Truck%20Concept%2026-Oct-05.pdf

Ensuring steady operation of free-piston generator
http://www.iiisci.org/journal/CV$/sci/pdfs/P651645.pdf

A novel concept of a Transverse Flux Linear Free-Piston Generator
http://kth.diva-portal.org/smash/get/diva2:453838/FULLTEXT01

A Linear Permanent Magnet Generator for a Free-Piston Energy Converter
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=1531540&queryText%3DFree-piston+Generator

Generic free-piston engine with transformer valve assembly for reducing throttling losses – Mannesmann Rexroth
http://www.google.es/patents/US6863507

Microgenerator of electrical energy – C.R.F. Societa Consortile per Azioni
http://www.google.cl/patents/US6932030

Linear-motion engine controller and related method - Aerovironment
http://www.google.com/patents/US6856107

Free piston engine and power generation system therewith  - Denso Corporation
http://www.google.com/patents/US6945202

Air scavenging for an opposed piston opposed cylinder free piston engine – Ford
http://www.google.com/patents/US6941904

Electromagnetic servo valve strategy for controlling a free piston engine - Ford
http://www.google.com/patents/US6971339

Compression pulse starting of a free piston internal combustion engine - Ford
http://www.google.com/patents/US6971340

Compression pulse starting of a free piston internal combustion engine having multiple cylinders - Ford
http://www.google.com/patents/US6966280

Electromagnetic servo valve strategy for controlling a free piston engine - Ford
http://www.google.com/patents/US6971339

Fuel injection for a free piston engine – Ford
http://www.google.com/patents/US6959672

Controllable combustion method and device – Sarcos Investments
http://www.google.com/patents/US6938588

Rapid response power conversion device
http://www.google.com/patents/US6957631

 

2004

 

Design Approach for a Two-Stroke Free Piston Engine for Electric Power Generation
http://papers.sae.org/2004-32-0037/

Computational Design Studies for a High-Efficiency and Low-Emissions Free Piston Engine Prototype
http://papers.sae.org/2004-01-2928/

Simulation of a Two-Stroke Free Piston Engine
http://papers.sae.org/2004-01-1871/

Linear Engine Development for Series Hybrid Electric Vehicles
http://bit.ly/1tb3grR

Use of transverse-flux machines in a free-piston generator
http://bit.ly/1yVZTIX

Possibilities of Linear Combustion Engine Control
http://bit.ly/1678oSD

Model and Experiments on Linear Combustion Engine
http://bit.ly/ZN18Lm

The Free Piston Engine: The Automotive Prime Mover of the Future?
http://bit.ly/15EhsuF

Device including a combustion engine, a use of the device, and a vehicle – ABB
http://www.google.com/patents/US6748907

Linear generator with induction coil which moves with respect to fixed permanent magnets – Dauber Holdings
http://www.google.com/patents/US6707175

Energy converter – Clavis Technology
http://www.google.com/patents/US6759755

 

2003

 

Toward the Development of a Thermodynamic Fuel Cell - DOE Sandia Labs
http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/merit03/28_snl_peter_van_blarigan.pdf

Developing a Thermodynamic Fuel Cell - DOE Sandia Labs
http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/ixb1_vanblarigan.pdf

APPLICATION OF A FREE-PISTON GENERATOR IN A SERIES HYBRID VEHICLE
http://www.ee.kth.se/php/modules/publications/reports/2003/IR-EE-EME_2003_020.pdf

The Free Piston Power Pack: Sustainable Power for Hybrid Electric Vehicles – Pempek Systems
http://papers.sae.org/2003-01-3277/

Optimizing the Scavenging System for a Two-Stroke Cycle, Free Piston Engine
for High Efficiency and Low Emissions: A Computational Approach - DOE Sandia Labs
http://papers.saeorg/2003-01-0001/

Fabrication and testing of linear electric generator for use with a free-piston engine
http://bit.ly/1CS2gd6

Use of transverse-flux machines in a free-piston generator
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=1210639&queryText%3DFree-piston+Generator

Dynamics and control of a free-piston diesel engine
http://www.itk.ntnu.no/ansatte/Johansen_Tor.Arne/klc_struc4.pdf

Dynamics and Control of a Free-Piston Diesel Engine
http://dynamicsystems.asmedigitalcollection.asme.org/article.aspx?articleid=1410073

INVESTIGATING MANUFACTURING DEFECTS IN A LINEAR TRANSVERSE-FLUX MACHINE FOR A FREE-PISTON GENERATOR
http://www.ee.kth.se/php/modules/publications/reports/2003/IR-EE-EME_2003_019.pdf

NUMERICAL SIMULATION FOR PARAMETRIC STUDY OF A TWO-STROKE
COMPRESSION IGNITION DIRECT INJECTION LINEAR ENGINE
http://bit.ly/1w4UNZH

USE OF TRANSVERSE-FLUX MACHINES IN A FREE-PISTON GENERATOR
http://www.ee.kth.se/php/modules/publications/reports/2003/IR-EE-EME_2003_028.pdf

A Low-Leakage Linear Transverse-Flux Machine for a Free-Piston Generator
http://kth.diva-portal.org/smash/record.jsf?pid=diva2:9382

ANALYTICAL ANALYSIS AND DIMENSIONING OF A LOWLEAKAGE
LINEAR TRANSVERSE-FLUX MACHINE
http://www.ee.kth.se/php/modules/publications/reports/2004/IR-EE-EME_2004_028.pdf

Design and development of a prototype free piston linear generator engine
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.109.5991&rep=rep1&type=pdf

Free piston engine with electrical power output - Caterpillar Inc
http://www.google.com/patents/US6541875

Opposed piston linearly oscillating power unit
http://www.google.com/patents/US6532916

Fully-controlled, free-piston engine – U.S. EPA
http://www.google.com/patents/US6652247

Fully-controlled, free-piston engine – U.S. EPA
http://www.google.com/patents/US6582204

Free-piston engines
http://www.google.com/patents/US6651599

Cyclically operated fluid displacement machine –Lotus Cars
http://www.google.com/patents/US6626650

Free-piston device provided with an electric linear drive
http://www.google.com/patents/WO2003091556A1?cl=en

 

2002

 

Investigation of Advanced Power Plants and Multiple Use Applications for Single Occupancy Vehicles - DOE Sandia Labs
http://prod.sandia.gov/techlib/access-control.cgi/2001/018711.pdf

FREE PISTON ENGINE MICRO ENGINE  - DARPA
http://www.me.umn.edu/~haich/engine/intro.html

TOWARDS A LINEAR ENGINE thesis
http://www-cdr.stanford.edu/dynamic/linear_engine/thesis.pdf

ADVANCED INTERNAL COMBUSTION ELECTRICAL GENERATOR
http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/32405b24.pdf

Numerical Simulation for Parametric Study of a Two-Stroke Direct Injection Linear Engine
http://papers.sae.org/2002-01-1739/

Miniature free-piston homogeneous charge compression ignition engine-compressor concept—Part I: performance
estimation and design considerations unique to small dimensions
http://www.me.umn.edu/~mrz/pdf_papers/2002_chem_E_sci_part1.pdf

Miniature free-piston homogeneous charge compression ignition engine-compressor concept—Part II: modeling
HCCI combustion in small scales with detailed homogeneous gas phase chemical
http://www.me.umn.edu/~mrz/pdf_papers/2002_chem_E_sci_part2.pdf

Design Considerations, Modeling, and Analysis of Micro- Homogeneous Charge Compression Ignition Combustion Free
-Piston Engines
http://www.menet.umn.edu/~haich/thesis2.pdf

Integrated Free-Piston Generators: An Overview
http://www.ee.kth.se/php/modules/publications/reports/2002/IR-EE-EME_2002_021.pdf

Finding an appropriate electrical machine for a free piston generator
http://www.ee.kth.se/php/modules/publications/reports/2002/IR-EE-EME_2002_003.pdf

Microcombustion engine/generator - Honeywell International Inc.
http://www.google.com/patents/US6397793

Miniature generator – Aerodyne Research
http://www.google.com/patents/US6349683

Free piston engine and self-actuated fuel injector therefor
http://www.google.com/patents/US6349682

 

2001

 

ADVANCED INTERNAL COMBUSTION ELECTRICAL GENERATOR - DOE
http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/30535bf.pdf

Investigation of Advanced Power Plants and Multiple Use Applications for Single Occupancy Vehicles Performance
Simulation of a Compression Ignition Free Piston Engine
http://prod.sandia.gov/techlib/access-control.cgi/2001/018711.pdf

Performance Simulation of a Compression Ignition Free Piston Engine
http://papers.sae.org/2001-01-0280/

Galileo Research CL&P Research Paper (Data on Initial Prototype, not ideal Free Piston Engine technology)
 (very large file, be patient after clicking)
Galileo Research CL&P Research Paper 

Galileo Prototype Adv Ignition DataTable 5-17-01A
2001 (Data on Initial Prototype Spark-Ignition Free Piston Engine)

Galileo Prototype DataTable 5-3-01-A
 2001 (Data on Initial Prototype Spark-Ignition Free Piston Engine)

Internal combustion engine for motor vehicle, has linear generator with permanent magnet(s) on piston rod moved axially
and reciprocally in coil winding when dual piston oscillates  - VW
http://worldwide.espacenet.com/publicationDetails/biblio?CC=DE&NR=19943993A1&KC=A1&FT=D

Micro-Homogeneous Charge Compression Ignition (HCCI) Combustion: Investigations Employing Detailed Chemical Kinetic
 Modeling and Experiments
http://www.menet.umn.edu/~haich/paper2.pdf

CONCEPTUAL ANALYSIS OF A FOUR-STROKE LINEAR ENGINE
http://wvuscholar.wvu.edu:8881//exlibris/dtl/d3_1/apache_media/L2V4bGlicmlzL2R0bC9kM18xL2FwYWNoZV9tZWRpYS81OTgw.pdf

Internal combustion engine for motor vehicle, has linear generator with permanent magnet(s) on piston rod  moved axially
and reciprocally in coil winding when dual piston oscillates  - VW
http://worldwide.espacenet.com/publicationDetails/biblio?CC=DE&NR=19943993A1&KC=A1&FT=D

Galileo Distributed Generation
Galileo Distributed Generation.pdf

Internal combustion engine for motor vehicle, has linear generator with permanent magnet(s) on piston rod
moved axially and reciprocally in coil winding when dual piston oscillates - VW
http://worldwide.espacenet.com/publicationDetails/biblio?CC=DE&NR=19943993A1&KC=A1&FT=D

Free-Piston Engine - DOE Sandia Labs
http://www.google.com/patents/US6199519

Free piston internal combustion engine – Sunpower
http://www.google.com/patents/US6170442

Microcombustion engine/generator – Honeywell International

http://www.google.com/patents/US6276313

 

2000

 

ADVANCED INTERNAL COMBUSTION ENGINE RESEARCH - DOE
http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/28890yy.pdf

Free Piston Engine Its Application and Optimization - FEV Engine Technology
http://papers.sae.org/2000-01-0996/

Comparison Between Single-Step and Two-Step Chemistry in a Compression Ignition Free Piston Engine
http://papers.sae.org/2000-01-2937/

A Diesel Two-Stroke Linear Engine
http://wvuscholar.wvu.edu:8881//exlibris/dtl/d3_1/apache_media/L2V4bGlicmlzL2R0bC9kM18xL2FwYWNoZV9tZWRpYS80Nzg0.PDF

First Cycles of the Dual Hydraulic Free Piston Engine
http://papers.sae.org/2000-01-2546/

Performance Simulation of a Compression Ignition Free Piston Engine
http://papers.sae.org/2001-01-0280/

Horsepower with Brains: The Design of the CHIRON Free Piston Engine
http://papers.sae.org/2000-01-2545/

Miniature reciprocating combustion-driven machinery – Georgia Tech Research
http://www.google.com/patents/US6109222

Method for absorbing the vibration of a free-piston engine and vibration-absorbed free-piston engine – Sampower
http://www.google.com/patents/US6135068

Method For Operating Of A Free Piston Engine - Caterpillar
http://www.google.com/patents/US6135069

Free Piston Internal Combustion Engine With Rotating  Piston – Caterpillar
http://www.google.com/patents/US6105541

Injector System For Free-Piston Engines
http://www.google.com/patents/US6050244

Free Piston Internal Combustion Engine – Sunpower
http://www.google.com/patents/US6035637

 

1999

 

Sandians' pursuit of ideal engine cycle for electricity generation wins honors
http://www.sandia.gov/LabNews/LN10-22-99/cycle_story.html

A Numerical Study of a Free Piston IC Engine Operating on Homogeneous Charge Compression Ignition Combustion -
DOE Sandia Labs
http://papers.sae.org/1999-01-0619/

Homogeneous Charge Compression Ignition Free Piston Linear Alternator - Sandia Labs
http://prod.sandia.gov/techlib/access-control.cgi/1999/998206.pdf

Numerical Simulation of a Two-Stroke Linear Engine-Alternator Combination
http://papers.sae.org/1999-01-0921/

High Output Alternator Concepts - BOSCH
http://papers.sae.org/1999-01-1092/

Design and testing of a novel linear alternator and engine system for remote electrical power generation
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=747434&contentType=Conference+Publications

Free-Piston Diesel-Fueled Linear Alternator for Auxiliary Power Unit Applications 1999
http://www.stormingmedia.us/33/3335/A333593.html

Field Analysis and Design of a Moving Iron Linear Alternator for Use with Linear Engine
http://wvuscholar.wvu.edu:8881/exlibris/dtl/d3_1/apache_media/L2V4bGlicmlzL2R0bC9kM18xL2FwYWNoZV9tZWRpYS80NjUy.pdf

Optimization of a brushless permanent magnet linear alternator for use with a linear
internal combustion engine
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.202.7885&rep=rep1&type=pdf

Free piston combustion engine with electrical energy delivery e.g. for hybrid automobile, heating plant or mobile current generator  
http://worldwide.espacenet.com/publicationDetails/biblio?CC=DE&NR=19813992A1&KC=A1&FT=D

Linear electrical energy generator
http://www.google.com/patents/US5893343

 

1998

 

Homogeneous Charge Compression Ignition with a Free Piston: A New Approach to Ideal Otto Cycle Performance –
DOE Sandia Labs
http://papers.sae.org/982484/

Fundamental Analysis of a Linear Two-Cylinder Internal Combustion Engine
http://papers.sae.org/982692/

Two-Stroke Linear Engine
http://bit.ly/1wiNZFi

Free piston internal combustion engine - Sunpower
https://www.google.com/patents/US5775273

Free piston variable-stroke linear-alternator generator – Lockheed Martin Energy
https://www.google.com/patents/US5850111

Electrically powered motor vehicle with linear electric generator
http://www.google.com/patents/US5788003

 

1997

 

Video – Galileo Prototype –1 - 1997
http://www.galileo-fpe.com/assets/multimedia/Galileo_FPE_1997_Prototype_Run.MPG

Linear electric actuators and generators
http://bib.convdocs.org/v24059/?download=1

 

1996

 

A High Specific Energy Output Free Piston Engine-Generator (HISEN-FPEG) for Hybrid Electric Vehicles
and Electric Utility Power Generation - Galileo Research 
http://bit.ly/ZFflto

The Combustion Process in a DI Diesel Hydraulic Free Piston Engine
http://papers.sae.org/960032/

Method for the cold start of a free-piston engine; and free-piston engine adapted for use of this method – Innas
Free Piston B.V.http://www.google.com/patents/US5540193

 

1995

 

FREE-PISTON ENGINE LINEAR GENERATOR FOR HYBRID VEHICLES MODELING STUDY
by Engine and Vehicle Research Division Southwest Research Institute FOR DARPA 1995
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA294318

Free-Piston Engine Linear Generator for Hybrid Vehicles Modeling Study –
Southwest Research for DARPA
http://www.stormingmedia.us/81/8134/A813492.html

 

1994

 

A Review of Free Piston Engine Concepts
http://papers.sae.org/941776/

A Free Piston Engine Generator
Galileo Research SBIR RA 94-024 DARPA PROPOSAL Part 1
http://galileo-fpe.com/assets/documents/Galileo-SBIR-RA-94-24-Proposal-Part-1-1994.pdf

A Free Piston Engine Generator
Galileo Research SBIR Proposal to Department of AIR FORCE 1994
http://galileo-fpe.com/assets/documents/Galileo-SBIR-AF94-182-Proposal-to-Department-of-AIR-FORCE-1994.pdf

Use of transverse-flux machines in a free-piston generator
http://bit.ly/1yVZTIX

Free piston engine control system - Tectonics
https://www.google.com/patents/US5287827

 

1993

Free Piston Engine-Generator Employing Homogeneous Charge Compression Ignition Type Combustion
(SBIR RA 93-24 Proposal to DARPA) - Galileo Research 
http://galileo-fpe.com/assets/documents/Galileo-SBIR-TRP-RA-93-24-Proposal-to-DARPA-1993.pdf

 

1991

Computer optimized hybrid engine
http://www.google.com/patents/US5002020

1990

Free-piston engine without compressor – RDG Inventions
http://www.google.com/patents/US4924956

Unsymmetrical free piston engine
http://www.google.com/patents/US4896632

1989

Internal combustion engine, particularly, a free-piston engine
http://www.google.com/patents/US4803960

Two stroke cycle engine
http://www.google.com/patents/US4876991

Internal combustion engine
http://www.google.com/patents/US4831972

1988

Design Feasibility of a Free Piston Internal Combustion Engine/Hydraulic Pump
http://papers.sae.org/880657/

1985

Method and apparatus for producing electrical energy from a cyclic combustion process utilizing coupled pistons which
 reciprocate in unison
http://www.google.com/patents/US4532431

1984

Free-piston engine with operatively independent cam
https://www.google.com/patents/US4480599

1983

Free-piston electric current generator
http://www.google.com/patents/US4403153

A Free Piston Engine-Pump for an Automotive Propulsion System
http://papers.sae.org/810266/

1979

Non-polluting heat machine with internal combustion - Jarret
http://www.google.com/patents/US4154200

1978

Free piston engine with opposed cylinders
http://www.google.com/patents/US4085711

1973

The Braun Linear Engine
http://papers.sae.org/730185/

COMBUSTION ENGINE DRIVEN GENERATOR INCLUDING SPRING STRUCTURE FOR OSCILLATING
THE INDUCTOR AT THE MECHANICAL RESONANT FREQUENCY BETWEEN POWER STROKES
http://www.google.com/patents/US3766399

FREE PISTON ENGINE STARTING APPARATUS
http://www.google.com/patents/US3769950

1972

FREE PISTON ENGINE IGNITION APPARATUS
http://www.google.com/patents/US3643638

1971

FREE PISTON GENERATOR - GE
http://www.google.com/patents/US3629596

BALANCED-FREE PISTON ENGINE
http://www.google.com/patents/US3610217

1970

Electromagnetic generators
http://www.google.com/patents/US3541362

1966

Free piston electrical generator
http://www.google.com/patents/US3234395

1963

Free-piston generator of electric current – Esso Research
http://www.google.com/patents/US3105153

1960

Floating Piston Engines - Jarret
http://www.google.com/patents/US2966148

1930

Internal combustion power plant
http://www.google.com/patents/US1785643

 

Free Piston Hydraulic Pump

2016

 

Design Approach and Dimensionless Analysis of a Differential Driving Hydraulic Free Piston Engine
http://papers.sae.org/2016-01-8091/

Three-Dimensional CFD Analysis of Semi-Direct Injection Hydraulic Free Piston Engine
http://papers.sae.org/2016-01-1018/

Free Piston Engine Based Mobile Fluid Power Source
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2604432

Free Piston Engine (FPE) Hydraulic Pump
http://news.nfpahub.com/fluid-power-research-update-free-piston-engine-hydraulic-pump/

INGOCAR 170 mpg Hydraulic Hybrid with Free-Piston Engine
https://www.youtube.com/watch?v=rCXnsitCYhw

Free Piston Engine (FPE) Hydraulic Pump
http://news.nfpahub.com/fluid-power-research-update-free-piston-engine-hydraulic-pump/

Free Piston Engine Based Mobile Fluid Power Source
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2604432

 

2015

Hydraulic hybrid vehicle with safe and efficient hydrostatic operation
https://www.google.com/patents/US9032723

Integrated hydraulic hybrid drivetrain system      Eaton Corporation
https://www.google.com/patents/US8992379

Hydrostatic drive system     Hydac Technology Gmbh
https://www.google.com/patents/US8959905

 

2014

The control of an opposed hydraulic free piston engine
]
The control of an opposed hydraulic free piston engine

High-efficiency linear combustion engine - Etagen, Inc.
http://www.google.com/patents/US8662029

Opposed piston internal combustion engine and method of operation thereof
ttp://www.google.com/patents/US8671681

 

2013

INGOCAR 170 mpg Hydraulic Hybrid with Free-Piston Engine
http://www.youtube.com/watch?v=rCXnsitCYhw

Transient Control of a Hydraulic Free Piston Engine
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1841152

Modeling and Control of Hydraulic Linear and Free-Piston Engines
\http://deepblue.lib.umich.edu/bitstream/handle/2027.42/102345/kzaseck_1.pdf?sequence=1

CCEFP update: Hydraulics and free piston engines
http://www.mobilehydraulictips.com/ccefp-update-hydraulics-free-piston-engines/

Center For Compact and Efficient Fluid Power
Hydraulic Hybrid Passenger Vehicle Test Bed 3: Highway Vehicles
http://www.ccefp.org/sites/all/files/documents/Info_TB3_HHPV.pdf

Center For Compact and Efficient Fluid Power
Project 2B.3: Free Piston Engine Hydraulic Pump
http://www.ccefp.org/sites/all/files/documents/Info_2B.3_Free_Piston_Eng_Hyd.pdf

Miniature Free Piston Engine for Fluid Power Applications
http://license.umn.edu/technologies/20120199_miniature-free-piston-engine-for-fluid-power-applications

Active Motion Control of a Hydraulic Free Piston Engine
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6583998

Free Piston Engine Hydraulic Pump 2B.3
http://www.ccefp.org/research/thrust-2-compactness/project-2b3

Semi-analytical modelling of a hydraulic free-piston engine
http://www.academia.edu/6077878/Semi-analytical_modelling_of_a_hydraulic_free-piston_engine

Extreme Power Free-Piston Engine
http://contest.techbriefs.com/2014/entries/machinery-automation-robotics/4509

Hydraulic internal combustion engines - Sturman Digital Systems
http://www.google.com/patents/US8596230

Hydraulic Hybrid Research
http://www.epa.gov/otaq/technology/research/research-hhvs.htm

Design and Modeling of a Novel Internal Combustion Engine with Direct Hydraulic Power Take-off
http://papers.sae.org/2013-01-1733/

For Excavators, Hydraulic Is the New Hybrid
http://enr.construction.com/products/equipment/2013/0506-for-excavators-hydraulic-is-the-new-hybrid.asp

A Hybrid That Has No Batteries
http://www.caranddriver.com/columns/a-hybrid-that-has-no-batteries

A serial hybrid concept
http://www.volumtran.com/Pages/VOLUMTRAN.aspx

The Chiron free piston hydraulic pump
http://www.innas.com/CFPE.html

Innas Hydrid Drive
http://www.innas.com/HD_main.html

Design and Modeling of a Novel Internal Combustion Engine with Direct Hydraulic Power Take-off
http://papers.sae.org/2013-01-1733/

Free Piston Engine Hydraulic Pump
http://www.ccefp.org/research/thrust-2-compactness/project-2b3

Active Motion Control of a Hydraulic Free Piston Engine
http://bit.ly/1wsSfTE

Hydraulic powertrain system
http://www.google.com/patents/US8449270

 

2012

 

On–off motion of a hydraulic free-piston engine
http://pid.sagepub.com/content/227/3/323.abstract

Study on Piston Motion Control Strategy of Single Piston Hydraulic Free-piston Engine
http://dl.acm.org/citation.cfm?id=2194316.2194335

Motion control of a hydraulic free-piston engine
http://bit.ly/1wsSgqM

Paired-piston linear engine
http://www.google.com/patents/US8091519

 

2011

 

Experimental Study on Hydraulic Free-Piston Diesel Engine
http://bit.ly/1rpRSD5

Flatness-Based High Frequency Control of a Hydraulic Actuator
http://dynamicsystems.asmedigitalcollection.asme.org/article.aspx?articleid=1415211

Stability Analysis of a Hydraulic Free Piston Engine With HCCI Combustion
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1638866

A Comparative Study of Permanent Magnet Linear Alternator and Hydraulic Free-Piston Engines

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1638333

 

2010

Center For Compact and Efficient Fluid Power
Project 2B.2: Miniature HCCI Free Piston Engine Compressor
http://www.ccefp.org/sites/all/files/documents/Info_2B.2_Mini_HCCI_FPE.pdf

Fluid dynamic modeling of a free piston engine with labyrinth seals
http://link.springer.com/article/10.1007%2Fs11630-010-0141-2

Experimental Study on Hydraulic Free Piston Diesel Engine
http://papers.sae.org/2010-01-2149/

Free-piston engine having variable stroke and method for operating a free-piston engine – Universal Motor Corp
http://www.google.com/patents/WO2010046120A1?cl=en

 

2009

 

Design approach for single piston hydraulic free piston diesel engines
http://link.springer.com/article/10.1007%2Fs11465-009-0069-y

A review of free-piston engine history and applications.
http://www.mikalsen.eu/papers/FPEreview.pdf

Hydraulic Hybrid Vehicle Energy Management System
http://papers.sae.org/2009-01-1772/

Hydraulic Hybrid Vehicle Energy Management System
http://papers.sae.org/2009-01-2834/

 

2008

 

HYDRAULIC DRIVE VEHICLES
http://www.designnews.com/article/7232-Hydraulic_Hybrid_Cars_No_Batteries_Required.php

LEDHO, a Linear Engine with Direct Hydraulic Output
http://www.dehyds.com/index.html

Modeling and Simulation of a Hydraulic Free Piston Diesel Engine
http://www.sae.org/technical/papers/2008-01-1528

Modeling and Simulation of a Hydraulic Free Piston Diesel Engine
http://papers.sae.org/2008-01-1528/

Developing a 10cc Single-Valve, Reverse Uniflow, 2S Engine
http://www.sae.org/technical/papers/2008-01-0953

Volumtran FPE Concept
http://www.volumtran.com/Pages/VOLUMTRAN.aspx

Four-Stroke Free Piston Engine
http://www.google.com/patents/US20080271711

Starting a compression ignition free piston internal combustion engine having multiple cylinders - Ford
http://www.google.com/patents/US6983724

Universal hybrid engine, compressor and pump, and method of operation
http://www.google.com/patents/US7373870

Internal combustion engine – Advanced Propulsion Technologies
http://www.google.com/patents/US7383796

Dynamic Mass Transfer Rapid Response Power Conversion System – Raytheon
http://www.google.com/patents/US7363887

 

2007

 

Introducing Hydraulic-Electric Synergy into Hybrid Transmission Using the Free-piston Engine Technology
http://papers.sae.org/2007-01-4112/

Internal combustion engine – Advanced Propulsion Technologies
http://www.google.com/patents/US7207299

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7255070

Rapid response power conversion device – Sarcos Investments
http://www.google.com/patents/US7210430

Four-cylinder, four-cycle, free piston, premixed charge compression ignition, internal combustion
reciprocating piston engine with a variable piston stroke
http://www.google.com/patents/US7258086

 

2006

 

EPA Hybrid Truck Initiative
http://files.harc.edu/Projects/Transportation/HydraulicHybridsGray.pdf

Control of dual hydraulic free piston engine
http://inderscience.metapress.com/content/27nae0bqtqkrkbb2/

Hydraulic synchronizing coupler for a free piston engine - Ford
http://www.google.com/patents/US7077080

Piston guides for a free piston engine - Ford
http://www.google.com/patents/US7032548

Starting a compression ignition free piston internal combustion engine having multiple cylinders  - Ford
http://www.google.com/patents/US6983724

Valve System For A Rapid Response Power Conversion Device – Sarcos Investments
http://www.google.com/patents/US7066116

Apparatus for determining free piston position and an apparatus for controlling free piston position – Global Cooling
http://www.google.com/patents/US7075292

 

2005

 

HYDRAULIC FREE PISTON ENGINE MAGAZINE ARTICLE
http://www.memagazine.org/backissues/membersonly/may05/departments/news_notes/news_note.html

Design, Development and Testing of Multi-Cylinder Hydraulic Free-Piston Engines
http://www.sae.org/technical/papers/2005-01-1167

Piston lubrication for a free piston engine – Ford
http://www.google.com/patents/US6971341

Piston stopper for a free piston engine - Ford
http://www.google.com/patents/US6973898

Fuel injection for a free piston engine - Ford
http://www.google.com/patents/US6959672

Opposed piston opposed cylinder free piston engine - Ford
http://www.google.com/patents/US6953010

Compression pulse starting of a free piston internal combustion engine having multiple cylinders - Ford
http://www.google.com/patents/US6966280

Compression pulse starting of a free piston internal combustion engine - Ford
http://www.google.com/patents/US6971340

Position sensing for a free piston engine - Ford
http://www.google.com/patents/US6948459

Air charging system for an opposed piston opposed cylinder free piston engine - Ford
http://www.google.com/patents/US6957632

Air scavenging for an opposed piston opposed cylinder free piston engine – Ford
http://www.google.com/patents/US6941904

Electromagnetic servo valve strategy for controlling a free piston engine - Ford
http://www.google.com/patents/US6971339


Exhaust gas recirculation for a free piston engine – Ford
http://www.google.com/patents/US6925971

Sodium cooled pistons for a free piston engine – Ford
http://www.google.com/patents/US6904876

Rapid response power conversion device – Sarcos Investments
http://www.google.com/patents/US6957631

Controllable combustion method and device – Sarcos Investments
http://www.google.com/patents/US6938588

Generic free-piston engine with transformer valve assembly for reducing throttling losses – Mannesmann Rexroth
http://www.google.com/patents/US6863507

Free piston engine – Bosch Rexroth
http://www.google.com/patents/US6931845

 

2004

 

Fundamental test results of a hydraulic free piston internal combustion engine
http://pid.sagepub.com/content/218/10/1149.abstract

Energy converter – Clavis Technology
http://www.google.com/patents/US6759755

Piston assembly for use in a free piston internal combustion engine - Caterpillar Inc
http://www.google.com/patents/US6694930

Free-piston unit for generating hydraulic energy – Innas Free Piston
http://www.google.com/patents/US6823671

 

2003

 

DESIGN, CONSTRUCTION, AND EXPERIMENTAL EVALUATION OF A
MONOPROPELLANT POWERED FREE PISTON HYDRAULIC PUMP
http://bit.ly/1CS2SzE

Fully-controlled, free-piston engine – U.S. EPA
http://www.google.com/patents/US6652247

Fully-controlled, free-piston engine – U.S. EPA
http://www.google.com/patents/US6582204

Cyclically operated fluid displacement machine –Lotus Cars
http://www.google.com/patents/US6626650

 

2002

 

Free piston engine system with direct drive hydraulic output - Caterpillar Inc.
http://www.google.com/patents/US6470677

Free piston internal combustion engine with pulse compression- Caterpillar Inc
http://www.google.com/patents/US6463895

Free-piston internal combustion engine
http://www.google.com/patents/US6484674

Piston Assembly For Free Piston Internal Combustion Engine - Caterpillar Inc.
http://www.google.com/patents/US6463903

 

2001

 

Performance Simulation of a Compression Ignition Free Piston Engine
http://papers.sae.org/2001-01-0280/

The development of the Innas free piston engine
http://bit.ly/16CwdnG

Method of operating a free piston internal combustion engine with high pressure hydraulic fluid upon misfire or initial
start-up – Caterpillar Inc
http://www.google.com/patents/US6206656

Free piston internal combustion engine with piston head functioning as a bearing
- Caterpillar Inc
http://www.google.com/patents/US6205961

Method of operating a free piston internal combustion engine with a short bore/stroke ratio - Caterpillar Inc
http://www.google.com/patents/US6314924

Free piston internal combustion engine
http://www.google.com/patents/US6293231

Free piston engine provided with a purging air dosing system - Innas Free Piston B.V.
http://www.google.com/patents/US6279517

Free piston internal combustion engine - Sunpower
http://www.google.com/patents/US6170442

Free piston internal combustion engine with pulse compression – Caterpillar Inc
http://www.google.com/patents/US6269783

Multi-piston hydraulic pump for a free piston engine – Sampower
http://www.google.com/patents/US6241488

Free piston internal combustion engine with piston head having non-metallic bearing surface – Caterpillar Inc
http://www.google.com/patents/US6216647

Free piston internal combustion engine with rotating piston – Caterpillar Inc
http://www.google.com/patents/US6244226

 

2000

 

Simulation of a Two-Stroke Compression Ignition Hydraulic Free Piston Engine
http://www.gtisoft.com/upload/HUT-Free-Piston.PDF

Horsepower with Brains: The Design of the CHIRON Free Piston Engine
http://papers.sae.org/2000-01-2545/

First Cycles of the Dual Hydraulic Free Piston Engine
http://papers.sae.org/2000-01-2546/

HYDRAULIC FREE PISTON ENGINE
http://www.icel.tkk.fi/research/Pulse_Two.html

Free piston internal combustion engine with piston head having a radially moveable cap – Caterpillar Inc
http://www.google.com/patents/US6164250

Method of operating a free piston internal combustion engine with a variable pressure hydraulic fluid output – Caterpillar Inc
http://www.google.com/patents/US6152091

Method for operation of a free piston engine – Caterpillar Inc
http://www.google.com/patents/US6135069

Method for operation of a free piston engine with pulse compression – Caterpillar Inc
http://www.google.com/patents/US6158401

Free piston internal combustion engine with rotating piston – Caterpillar Inc
http://www.google.com/patents/US6105541

Free piston engine – Split Cycle Technology Ltd
http://www.google.com/patents/US6029616

Free-piston internal combustion engine – Sunpower
http://www.google.com/patents/US6035637

Method for absorbing the vibration of a free-piston engine and vibration-absorbed free-piston engine –
Sampower
http://www.google.com/patents/US6135068

Injector system for free-piston engines
http://www.google.com/patents/US6050244

 

1999

 

Hydraulic switching valve, and a free piston engine provided therewith - Innas Free Piston B.V.
http://www.google.com/patents/US5983638

 

1998

 

The development of the Innas Free Piston Engine
http://bit.ly/19a1qib

Free piston internal combustion engine - Sunpower
http://www.google.com/patents/US5775273

Free-piston engine - Innas Free Piston
http://www.google.com/patents/US5829393

Computerized internal supercharged engine-pump
http://www.google.com/patents/US5813371

 

1997

 

Free piston internal combustion engine
http://www.google.com/patents/US5678522

 

1996

 

The Combustion Process in a DI Diesel Hydraulic Free Piston Engine
http://papers.sae.org/960032/

Free-piston engine having a fluid energy unit - Innas Free Piston B.V.
http://www.google.com/patents/US5556262

Free-piston engine having a slidable ring for moving the piston - Innas Free Piston B.V.
http://www.google.com/patents/US5482445

Method for the cold start of a free-piston engine; and free-piston engine adapted for use of this method -
Innas Free Piston B.V.
http://www.google.com/patents/US5540193

Reciprocating system
http://www.google.com/patents/US5540194

 

1995

 

Free-piston engine having a fluid pressure unit - Innas Free Piston B.V.
http://www.google.com/patents/US5473893

 

1994

 

A Review of Free Piston Engine Concepts
http://www.sae.org/technical/papers/941776

Vehicular drive system using stored fluid power for improved efficiency
http://www.google.com/patents/US5327857

Free piston engine control system – Tectonics Companies
http://www.google.com/patents/US5287827

Free piston internal combustion engine
http://www.google.com/patents/US5363651

 

1993

A Prime Mover Consists of a Free Piston Internal Combustion Hydraulic Power Generator and a Hydraulic Motor
http://papers.sae.org/930313/

 

1992

 

Design of a Free-Piston Engine-Pump
http://papers.sae.org/921740/

A Prime Mover Consists of a Free Piston Internal Combustion Hydraulic Power Generator and a Hydraulic Motor
http://papers.sae.org/930313/

Method and apparatus for starting a free piston combustion engine hydraulically - Sampower
http://www.google.com/patents/US5123245

 

1991

 

Silencer for Hydraulic Piston Pump Pressure Pulsations
http://papers.sae.org/911759/

Fluid power engine
http://www.google.com/patents/US5036667

Computer optimized hybrid engine
http://www.google.com/patents/US5002020

 

1990

 

Internal combustion engine with fluid drive output
http://www.google.com/patents/US4966000

Unsymmetrical free piston engine
http://www.google.com/patents/US4896632

 

1989

 

Internal combustion engine
http://www.google.com/patents/US4831972

Internal combustion engine, particularly, a free-piston engine
http://www.google.com/patents/US4803960

Free piston engine-pump propulsion system
http://www.google.com/patents/US4891941

 

1988

 

Design Feasibility of a Free Piston Internal Combustion Engine/Hydraulic Pump
http://papers.sae.org/880657/

A Free-Piston Engine Hydraulic Pump for an Automotive Propulsion System - GM
http://papers.sae.org/880658/

Free-piston motor with hydraulic or pneumatic energy transmission
http://www.google.com/patents/US4791786

 

1986

 

Oil pump with oscillating piston
http://www.google.com/patents/US4620836

Internal combustion hydraulic engine
http://www.google.com/patents/US4599861

 

1984

 

Hydraulic pump with variable-stroke piston and generator using said pump - Airmachines
http://www.google.com/patents/US4461613

Free piston engine pump with energy rate smoothing – Pneumo Corp.
http://www.google.com/patents/US4435133

 

1983

 

Hydraulic generator with free-piston engine – Regie Nationale des Usines Renault
https://www.google.com/patents/US4415313

Opposed piston type free piston engine pump unit – Pneumo Corp.
http://www.google.com/patents/US4382748

Free-piston engine pump
https://www.google.com/patents/US4369021

 

1982

 

Linear engine/hydraulic pump – Pneumo Corp.
http://www.google.com/patents/US4308720

Hydraulic engine
http://www.google.com/patents/US4326380

Internal combustion engine or pumping device
http://www.google.com/patents/US4362477

 

1981

 

A Free Piston Engine-Pump for an Automotive Propulsion System
http://papers.sae.org/810266/

Free piston engine pump including variable energy rate and acceleration-deceleration controls – Pneumo Corp.
http://www.google.com/patents/US4307999

 

1978

 

Free-piston engine-pump unit
http://www.google.com/patents/US4087205

Gas cushioned free piston type engine
http://www.google.com/patents/US4128083

Free-piston engine with opposed cylinders
http://www.google.com/patents/US4085711

 

1976

 

Resonant gas-expansion engine with hydraulic energy conversion
http://www.google.com/patents/US3932989

 

1973

 

The Braun Linear Engine
http://papers.sae.org/730185/

FREE PISTON ENGINE STARTING APPARATUS
http://www.google.com/patents/US3769950

 

1972

 

FREE PISTON ENGINE IGNITION APPARATUS
http://www.google.com/patents/US3643638

 

1971

 

BALANCED-FREE PISTON ENGINE
http://www.google.co.uk/patents/US3610217

 

1959

 

FORD FREE-PISTON ENGINE DEVELOPMENT
http://papers.sae.org/590045/

 

1958

 

The Future of the FREE-PISTON ENGINE in Commercial Vehicles - FORD
http://papers.sae.org/580032/

SIMULATION OF A FREE-PISTON ENGINE WITH A DIGITAL COMPUTER - GM
http://papers.sae.org/580267/

 

1957

 

THE AUTOMOTIVE FREE-PISTON-TURBINE ENGINE - FORD
http://papers.sae.org/570051/

Observations on 25,000 Hours of Free-Piston-Engine Operation - GM
http://papers.sae.org/570042/

THE GMR 4-4 “HYPREX” ENGINE A CONCEPT OF THE FREE-PISTON ENGINE FOR
AUTOMOTIVE USE - GM
http://papers.sae.org/570032/

 

Free Piston Pump

 

2010

 

Free-piston engine having variable stroke and method for operating a free-piston engine – Universal Motor Corp
http://www.google.com/patents/WO2010046120A1?cl=en

 

2008

 

Internal combustion engine – Advanced Propulsion Technologies
http://www.google.com/patents/US7383796

 

2007

 

Internal combustion engine – Advanced Propulsion Technologies
http://www.google.com/patents/US7207299

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7255070

Rapid response power conversion device – Sarcos Investments
http://www.google.com/patents/US7210430

Valve system for a rapid response power conversion device - Sarcos Investments
http://www.google.com/patents/US7066116

Four-cylinder, four-cycle, free piston, premixed charge compression ignition, internal combustion reciprocating
piston engine with a variable piston stroke
http://www.google.com/patents/US7258086

 

2006

 

Apparatus for determining free piston position and an apparatus for controlling free piston position – Global Cooling
http://www.google.com/patents/US7075292

 

2005

 

Compression pulse starting of a free piston internal combustion engine having multiple cylinders - Ford
http://www.google.com/patents/US6966280

Compression pulse starting of a free piston internal combustion engine - Ford
http://www.google.com/patents/US6971340

Electromagnetic servo valve strategy for controlling a free piston engine – Ford
http://www.google.com/patents/US6971339

 

2004

 

Energy converter – Clavis Technology
http://www.google.com/patents/US6759755

 

2002

 

NASA FREE PISTON ENGINE PUMP
http://sbir.gsfc.nasa.gov/SBIR/abstracts/02/sbir/phase1/SBIR-02-1-H3.02-9677.html

 

2001

 

Free piston internal combustion engine - Sunpower
http://www.google.com/patents/US6170442

 

2000

 

Method for operating of a free piston engine – Caterpillar Inc
http://www.google.com/patents/US6135069

Free piston internal combustion engine with rotating piston – Caterpillar Inc
http://www.google.com/patents/US6105541

Injector system for free-piston engines
http://www.google.com/patents/US6050244

Free-piston internal combustion engine - Sunpower
http://www.google.com/patents/US6035637

 

1998

 

Computerized internal supercharged engine-pump
http://www.google.com/patents/US5813371

Free-piston engine – Innas Free Piston
http://www.google.com/patents/US5829393

Free-piston internal combustion engine - Sunpower
http://www.google.com/patents/US5775273

 

1994

 

Free-piston engine control system – Tectonics
http://www.google.com/patents/US5287827

 

1992

 

Design of a Free-Piston Engine-Pump
http://papers.sae.org/921740/

 

1990

 

Free-piston engine without compressor – RDG Inventions
http://www.google.com/patents/US4924956

 

1989

 

Internal combustion engine
http://www.google.com/patents/US4831972

Internal combustion engine, particularly, a free-piston engine
http://www.google.com/patents/US4803960

 

1988

 

Free-piston motor with hydraulic or pneumatic energy transmission
http://www.google.com/patents/US4791786

 

1986

 

Oil pump with oscillating piston
http://www.google.com/patents/US4620836

 

1983

 

Free-piston engine pump
https://www.google.com/patents/US4369021

Opposed piston type free piston engine pump unit
http://www.google.com/patents/US4382748

 

1982

 

Hydraulic engine
http://www.google.com/patents/US4326380

Linear engine/hydraulic pump – Pneumo Corp.
http://www.google.com/patents/US4308720

Internal combustion engine or pumping device
http://www.google.com/patents/US4362477

 

1981

 

A Free Piston Engine-Pump for an Automotive Propulsion System
http://papers.sae.org/810266/

Free piston engine pump including variable energy rate and acceleration-deceleration controls – Pneumo Corp
ttp://www.google.com/patents/US4307999

 

1978

 

Free-piston engine-pump unit
http://www.google.com/patents/US4087205

Gas cushioned free piston type engine
http://www.google.com/patents/US4128083

Free piston engine with opposed cylinders
http://www.google.com/patents/US4085711

 

1973

 

The Braun Linear Engine
http://papers.sae.org/730185/

FREE PISTON ENGINE STARTING APPARATUS
http://www.google.com/patents/US3769950

 

1972

 

Free piston engine ignition apparatus
http://www.google.com/patents/US3643638

 

1971

 

BALANCED-FREE PISTON ENGINE
http://www.google.com/patents/US3610217

 

Free Piston Compressor 2016

Miniature Free Piston Engine Compressor
http://erc-assoc.org/content/miniature-free-piston-engine-compressor

 

2014

Free Piston Engine Compressor 2B.1
http://www.ccefp.org/research/thrust-2-compactness/project-2b1

Minature HCCI Free Piston Engine Compressor 2B.2
http://www.ccefp.org/research/thrust-2-compactness/miniature-hcci-free-piston-engine-compressor

 

2013

Miniature homogeneous charge compression ignition free-piston engine compressor
http://gradworks.umi.com/35/89/3589193.html

Dynamic modeling of a SI/HCCI free-piston engine generator with electric mechanical valves
http://econpapers.repec.org/article/eeeappene/v_3a102_3ay_3a2013_3ai_3ac_3ap_3a336-346.htm

EGR constructions for opposed-piston engines - Achates Power, Inc
http://www.google.com/patents/US8549854

The High Inertance Free Piston Engine Compressor—Part I: Dynamic Modeling
http://dynamicsystems.asmedigitalcollection.asme.org/article.aspx?articleid=1682750

The High Inertance Free Piston Engine Compressor—Part II: Design and Experimental Evaluation
http://dynamicsystems.asmedigitalcollection.asme.org/article.aspx?articleid=1682053#

Hydraulic powertrain system
http://www.google.com/patents/US8449270

 

2012

 

A miniature free-piston engine/compressor
http://www.me.umn.edu/~wkdurfee/publications/engine-compressor-IJER-2012.pdf

Free-piston Engine Compressor
http://www.ccefp.org/research/thrust-2-compactness/project-2b1

Miniature HCCI Free-piston Engine Compressor
http://www.ccefp.org/research/thrust-2-compactness/project-2b2

A miniature free-piston engine/compressor
http://www.me.umn.edu/~wkdurfee/publications/engine-compressor-IJER-2012.pdf

Free-piston engine having variable stroke and method for operating a free-piston engine – Universal Motor Corp
http://www.google.com/patents/WO2010046120A1?cl=en

 

2011

Project 2B.1: Free Piston Engine Compressor  DATE ? 2011
http://www.ccefp.org/sites/all/files/documents/Info_2B.1_Free_Piston_Eng_Comp.pdf

 

2009

 

Coupled dynamic–multidimensional modelling of free-piston engine Combustion
http://www.mikalsen.eu/papers/FPEcoupledSolver.pdf

Reducing Piston Mass in a Free Piston Engine Compressor by Exploiting the Inertance of a Liquid Piston
http://www.vanderbilt.edu/dces/PDF/papers/conference/DSCC2009_HI-FLPC_paper.pdf

MODELING AND CONTROL OF A HIGH PRESSURE COMBINED AIR/FUEL INJECTION SYSTEM
http://www.vanderbilt.edu/dces/PDF/papers/conference/DSCC2009_high_pressure_af_control.pdf

Free-Piston Engine Compressor   Poster  2009
NSF Site Visit for the Center for Compact and Efficient Fluid Power (CCEFP), April 28-30, 2009,
University of Minnesota, Minneapolis, MN.
http://www.vanderbilt.edu/dces/PDF/Posters/2B1%20Poster%2009%20nsf%20site%20visit.pdf

 

Combustion-powered linear air motor/compressor
http://www.google.com/patents/US7634979

 

2008

 

Developing a 10cc Single-Valve, Reverse Uniflow, 2S Engine
http://www.sae.org/technical/papers/2008-01-0953

Experimental Assessment of a Free Elastic-Piston Engine Compressor with Separated Combustion Chamber
http://www.vanderbilt.edu/dces/PDF/papers/conference/bath08_Riofrio_Barth.pdf

Modeling and Control of a Free Liquid-Piston Engine Compressor
http://www.vanderbilt.edu/dces/PDF/papers/conference/Bath08_Yong_Barth_Riofrio.pdf

Free Liquid-Piston Engine Compressor with Separated Combustion Chamber   Poster
NSF Site Visit for the Center for Compact and Efficient Fluid Power (CCEFP), February 20, 2008,
University of Minnesota, Minneapolis, MN.
http://www.vanderbilt.edu/dces/PDF/Posters/2B%20design%20poster%20feb%2008.pdf

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7383796

 

2007

 

Design and Analysis of a Resonating Free Liquid-Piston Engine Compressor
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1599051

Free Liquid-Piston Engine Compressor with External Combustion Chamber
http://www.vanderbilt.edu/dces/PDF/Posters/2B%20poster%20apr%2007.pdf

A FREE PISTON COMPRESSOR AS A PNEUMATIC MOBILE ROBOT POWER
SUPPLY: DESIGN, CHARACTERIZATION AND EXPERIMENTAL OPERATION
http://www.vanderbilt.edu/dces/PDF/papers/journal/Riofrio%20Barth%20FPC%20Int%20J%20of%20Fluid%20Power.pdf

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7255070

Internal combustion engine – Advanced Propulsion Technologies
https://www.google.com/patents/US7207299

Four-cylinder, four-cycle, free piston, premixed charge compression ignition, internal combustion reciprocating piston
engine with a variable piston stroke
http://www.google.com/patents/US7258086

 

2006

 

Free-Piston Compressor for Portable Fluid Power Systems   Poster
NSF Site Visit for the Center for Compact and Efficient Fluid Power, University of Minnesota, October 2006,
Minneapolis, MN.
http://www.vanderbilt.edu/dces/PDF/Posters/VU%20ERC%20poster%202B%20Oct%2006.pdf

Valve system for a rapid response power conversion device – Sarcos Investments
http://www.google.com/patents/US7066116

Apparatus for determining free piston position and an apparatus for controlling free piston position – Global Cooling
http://www.google.com/patents/US7075292

 

2005

 

EXPERIMENTAL OPERATION AND CHARACTERIZATION
OF A FREE PISTON COMPRESSOR
http://www.vanderbilt.edu/dces/PDF/papers/conference/IMECE2005_fpc_final.pdf

Free-Piston Compressor for Portable Fluid Power Systems   Poster
NSF Proposal Site Visit for the Center for Compact and Efficient Fluid Power, University of Minnesota,
November 2005, Minneapolis, MN.
http://www.vanderbilt.edu/dces/PDF/Posters/VU%20ERC%20poster%20Jose%20Riofrio%2005.pdf

Design of a Free Piston Pneumatic Compressor as a Mobile Robot Power Supply
http://www.vanderbilt.edu/dces/PDF/papers/conference/icra05_fpc_published.pdf

Compression pulse starting of a free piston internal combustion engine - Ford
http://www.google.com/patents/US6971340

Electromagnetic servo valve strategy for controlling a free piston engine - Ford
http://www.google.com/patents/US6971339

Compression pulse starting of a free piston internal combustion engine having multiple cylinders - Ford
http://www.google.com/patents/US6966280

 

2004

 

Dynamic Characteristics of a Free Piston Compressor
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1652558

Energy converter – Clavis Technology
http://www.google.com/patents/US6759755

 

2003

 

DESIGN, CONSTRUCTION, AND EXPERIMENTAL EVALUATION OF A MONOPROPELLANT
POWERED FREE PISTON HYDRAULIC PUMP
http://bit.ly/1CS2SzE

Fully-controlled, free-piston engine – US EPA
http://www.google.com/patents/US6652247

Fully-controlled, free-piston engine – US EPA
http://www.google.com/patents/US6582204

Cyclically operated fluid displacement machine –Lotus Cars
http://www.google.com/patents/US6626650

 

2001

 

The control of an opposed hydraulic free piston engine
http://econpapers.repec.org/article/eeeappene/v_3a126_3ay_3a2014_3ai_3ac_3ap_3a213-220.htm

Free piston internal combustion engine – Sunpower
http://www.google.com/patents/US6170442

 

2000

 

Free-piston internal combustion engine - Sunpower
http://www.google.com/patents/US6035637

Method for operation of a free piston engine
http://www.google.com/patents/US6135069

Free piston internal combustion engine with rotating piston
http://www.google.com/patents/US6105541

Injector System for free-piston engines
http://www.google.com/patents/US6050244

 

1998

 

Free-piston engine - Innas Free Piston
http://www.google.com/patents/US5829393

 

Free piston internal combustion engine – Sunpower
http://www.google.com/patents/US5775273

 

1995

 

FREE PISTON ENGINE COMPRESSOR
http://www.stormingmedia.us/25/2543/A254392.html?searchTerms=free~piston

 

1994

 

Free piston engine control system – Tectonics
http://www.google.com/patents/US5287827

 

1992

 

Circuit for controlling a free-piston engine in particular of a refrigerator compressor - Whirlpool
http://www.google.com/patents/US5079924

 

1989

 

Internal combustion engine
http://www.google.com/patents/US4831972

Internal combustion engine, particularly, a free-piston engine
http://www.google.com/patents/US4803960

 

1988

 

Free-piston motor with hydraulic or pneumatic energy transmission - De Rotterdamsche
http://www.google.com/patents/US4791786

 

1987

 

Bounce chambers for multi-cylinder linear engine compressors
http://www.google.com/patents/US4705460

 

1979

 

Method and device for ensuring the safety in a free piston machine
http://www.google.com/patents/US4142485

 

1978

 

Free piston engine with opposed cylinders
http://www.google.com/patents/US4085711

 

1973

 

The Braun Linear Engine
http://papers.sae.org/730185/

FREE PISTON ENGINE STARTING APPARATUS
http://www.google.com/patents/US3769950

 

1972

 

Free piston engine ignition apparatus
http://www.google.com/patents/US3643638

 

1970

 

Tandem, free-piston macines
http://www.google.com/patents/US3501087

1959

 

Power sources
http://www.google.com/patents/US2900592

1928

Motor-compressor apparatus
http://www.google.com/patents/US1657641

Linear engine for compressor and compressor provided with a linear engine
http://www.google.com/patents/US20140241916

 

 

OTHER Free Piston Engine Uses

2014

 

Ultra-efficient hydraulic hybrid drivetrain and method of operation
http://www.google.com/patents/US8646558

 

2012

 

The High Performance Toroidal Engine Concept (HiPerTEC)
http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1627452

Two-stroke HCCI compound free-piston/gas-turbine engine
http://www.google.com/patents/US8127544

 

2010

 

Process to obtain thermal and kinetic energy from a geothermal heat source using supercritical CO2 – GreenFire Partners
http://www.google.com/patents/US20110100002

 

2009

 

Miniature HCCI Free-Piston Engine Compressor For Orthosis Application
http://papers.sae.org/2009-32-0176/

 

2008

 

Rotary Shaft Power Extraction From a Free-Piston Engine
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2008/poster3/deer08_fitzgerald.pdf

Modeling and Control of the Free Liquid-Piston Engine Compressor   Poster 2008
NSF Site Visit for the Center for Compact and Efficient Fluid Power (CCEFP), February 20, 2008,
University of Minnesota, Minneapolis, MN.
http://www.vanderbilt.edu/dces/PDF/Posters/2B%20modeling%20control%20poster%20feb%2008.pdf

Free Liquid-Piston Engine Compressor with Separated Combustion Chamber   Poster
NSF Site Visit for the Center for Compact and Efficient Fluid Power (CCEFP), February 20, 2008,
University of Minnesota, Minneapolis, MN.
http://www.vanderbilt.edu/dces/PDF/Posters/2B%20design%20poster%20feb%2008.pdf

Dynamic mass transfer rapid response power conversion system – Raytheon Sarcos
http://www.google.com/patents/US7363887

Free piston vacuum producing apparatus
http://www.google.com/patents/US7467607

 

2007

 

Free Liquid-Piston Engine with External Combustion Camber   Poster
1st Annual Meeting for the Center for Compact and Efficient Fluid Power, Georgia Institute of Technology,
April 2007, Atlanta, GA.
http://www.vanderbilt.edu/dces/PDF/Posters/2B%20poster%20apr%2007.pdf

The Hydrid Transmission
http://papers.sae.org/2007-01-4152/

 

2006

 

Apparatus for determining free piston position and an apparatus for controlling free piston position – Global Cooling
http://www.google.com/patents/US7075292

Two-stroke internal combustion engine with free opposed pistons – FEV
http://www.google.com/patents/US7047916

Apparatus for determining free piston position and an apparatus for controlling free piston position – Global Cooling
http://www.google.com/patents/US7075292

 

2005

 

Microgenerator of electrical energy – C.R.F. Societa Consortile per Azioni
http://www.google.com/patents/US6932030

 

Controllable combustion method and device - Mechanical Transducer – Sarcos Investments
http://www.google.com/patents/US6938588

 

2004

 

Piston assembly for use in a free piston internal combustion engine - Caterpillar Inc
http://www.google.com/patents/US6694930

Energy converter – Clavis Technology
http://www.google.com/patents/US6759755

 

2002

 

Uniflow scavenging microengine – US Air Force
http://www.google.com/patents/US6460493

Piston assembly for free piston internal combustion engine - Caterpillar Inc
http://www.google.com/patents/US6463903

Microcombustion engine/generator – Honeywell
http://www.google.com/patents/US6397793

Free piston engine and self-actuated fuel injector therefore
http://www.google.com/patents/US6431146

Free piston engine and self-actuated fuel injector
http://www.google.com/patents/US6349682

Piston Assembly For Free Piston Internal Combustion Engine - Caterpillar Inc.
http://www.google.com/patents/US6463903

 

2001

 

Microcombustion engine/generator – Honeywell
http://www.google.com/patents/US6276313

 

2000

 

Free piston internal combustion engine – Sunpower
http://www.google.com/patents/US6035637

 

1999

 

Power plant – Kvaerner ASA
http://www.google.com/patents/US5913290

 

1998

 

Free piston internal combustion engine – Sunpower
http://www.google.com/patents/US5775273

Electrically powered motor vehicle with linear electric generator
http://www.google.com/patents/US5788003

 

1997

 

Free piston internal combustion engine
http://www.google.com/patents/US5678522

 

1996

 

Development of a Hydrogen Fueled Internal Combustion Engine Designed for Single Speed/Power Operation
http://papers.sae.org/961690/

 

1995

 

Series Hybrid Vehicles and Optimized Hydrogen Engine Design
http://www.osti.gov/bridge/servlets/purl/104996-Wnv0bi/webviewable/104996.pdf

Linear electrodynamic machine - Clever Fellows Innovation Consortium
http://www.google.com/patents/US5389844

 

1994

 

Vehicular drive system using stored fluid power for improved efficiency
http://www.google.com/patents/US5327857

 

1992

 

Magnetic Bearings for Free-Piston Stirling Engines - NASA
http://papers.sae.org/929383/

HOTS to WATTS: The FPSE Linear Alternator System Re-Invented
http://papers.sae.org/929261/

Hybrid electric propulsion system
http://www.google.com/patents/US5172784

 

1984

Free piston internal combustion engine Turbine
http://www.google.com/patents/US4449488

1970

Tandem, free-piston machines
http://www.google.com/patents/US3501087

1967

 

FREE PISTON-PULSED TURBINE ENGINE
http://www.google.com/patents/US3359719

1959

Free Piston Electric Power Generator Set & Combustion Research

FORD FREE-PISTON ENGINE DEVELOPMENT
http://papers.sae.org/590045/

1956

Free Piston Electric Power Generator Set & Combustion Research

1956 General Motors XP 500 Free Piston Prototype
https://www.youtube.com/watch?v=Anbm8a-HT9s

 

 

1957

 

 Popular Science, September 1957, pp. 138-141/294, detailed article/cutaway drawing on free-piston diesel engines. "Engine of Tomorrow - Goes to Work Today."
http://bit.ly/1t4dyKC

Design and Application of Marine Free-Piston Gas Generators
http://bit.ly/1vJsoa2

THE GMR 4-4 “HYPREX” ENGINE A CONCEPT OF THE FREE-PISTON ENGINE FOR AUTOMOTIVE USE
http://papers.sae.org/570032/

THE GMR 4-4 “HYPREX” ENGINE A CONCEPT OF THE FREE-PISTON ENGINE FOR AUTOMOTIVE USE
http://papers.sae.org/570032/

1952

Toutant W.T., The Worthington-Junkers free-piston aerkunpremilo, Journal of the American Society of
Naval Engineers 1952:64:583-594 
.
London A.L., Oppenheim A.K., The free-piston engine development - Present status and design aspects, 
Transactions of the ASME 1952:74:1349-1361 .
The free piston gas generator: a verification of the Oppenheim-London design method
https://archive.org/details/freepistongasgen00welg

 

1930

Internal combustion power plant
http://www.google.com/patents/US1785643

LINEAR ENGINE   http://galileo-fpe.com/Linear Engine Database.pdf

FREE PISTON ENGINE   http://galileo-fpe.com/Free Piston Engine.pdf

FREE PISTON ENGINES   http://galileo-fpe.com/Free Piston Engines.pdf

FREE PISTON ENGINE DATA   http://galileo-fpe.com/Free Piston Engine Data.pdf

FREE PISTON ENGINE DATABASE   http://galileo-fpe.com/Free Piston Engine Database.pdf

FREE PISTON ENGINE DATABASE   http://free-piston-engines.com/Free-Piston-Engine-Database.pdf