Piston motion control

Control of the piston motion in free-piston engines is a non-trivial problem and critical for the viability of this engine concept. Since there is no crankshaft restricting the piston motion, the free-piston engine has the potentially very valuable feature of variable compression ratio. However, if this advantage is to be utilised, accurate control of the piston endpoints (dead centres) must be realised. An "electronic crankshaft" is required.

The group has studied a variety of aspects related to free-piston engine control, including feed forward and predictive methods to improve system load handling capability and reduce cycle-to-cycle variations.