Abstract
This paper presents the design and control of a free-liquid-piston engine compressor (FLPEC). The FLPEC produces low temperature, high-pressure air for use as a high energy density power supply for untethered, compact robots. Internal combustion with a propane-air mixture in the engine combustion chamber drives a high inertance, low mass liquid piston, which compresses air into an onboard reservoir. A real time logical controller is implemented in Matlab to regulate the timings of the air and fuel injection, spark, and exhaust valve and to compensate for misfires. Experimental pressure data is overlaid with the logical state of the injectors, spark plug, and exhaust valve to demonstrate the efficacy of the controller to account for cycle-to-cycle pressure variations in the combustion chamber.Copyright for articles published in this journal is retained by the authors, with first publication rights granted to Vanderbilt Undergraduate Research Journal under a Creative Commons Attribution-Noncommercial-ShareAlike 4.0 International License (linked here). By virtue of their appearance in this open access journal, articles are available for wide dissemination at no cost to readers, with proper attribution (acknowledgment of the work's authorship and initial publication in this journal), in educational and other non-commercial settings. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process.
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