Free-piston diesel engine dynamics and control

Free-piston diesel engines are characterized by freely moving pistons without any rigid crankshaft or camshaft connected to the pistons. This allows a highly compact and efficient engine design, but requires automatic control of the piston motion. This paper present a dynamic mathematical model of a free-piston diesel engine, a control oriented dynamic analysis, and a novel computer-based piston motion control system. Experimental evaluation of the results on a full scale diesel test cylinder show feasibility of the suggested control approach.