On hysteresis and air gap disturbance in current and voltage mode feed-forward control of variable reluctance actuators

Current and voltage mode control approaches in feed-forward force control of variable reluctance actuators are analyzed and compared. Two major error generators, the unknown air gap variation and hysteresis, are investigated together with the quantification of their influence on the final force tracking error, and it is shown that voltage control has fundamental advantages over current control. Furthermore, linearization laws with hysteresis compensation based on the parametric hysteresis operator are proposed and compared on a high-fidelity actuator model which is derived from the behavior of magnetic materials, the actuator structure, and first principle physical models.