The system includes a loss compensation controller 16, first and second actuators 18, 20, an armature element 26, restoring springs 22, 24 and a motion detector 32. Position and optionally movement signals from motion detector 32, which may comprise a permanent magnet and a coil, are used in controller 16 to calculate mechanical losses of the armature element (particularly due to friction eddy currents and aerodynamic forces) and control the actuators to reduce the impact of the armature element 26 on the actuators. In operation, the actuator holding the armature is unpowered and reaching of the midpoint by the actuator is detected by motion detector 32. Mechanical losses are calculated. The other actuator is powered for sufficient time to give the armature adequate energy to reach the other actuator (taking the calculated mechanical losses into consideration) and is then unpowered so that the armature freewheels to the other actuator, which is then powered to hold the armature. The actuators may be driven by a regenerative switching power converter 14.
Electromechanical engine valve actuator system with loss compensation controller