Improvement of position tracking and magnetic-levitation control based on optimal-control for helical motor

For various assistive devices, safe and compact high output actuators are desired. The authors have proposed a helical motor that consists of a helical mover and stator. In the latest study, a motion controller of a helical motor is based on PD-control law and disturbance observer. However, the performance of the conventional controller is not enough to achieve more high preciesion motion and robustness. Therefore, this paper presents a comparison between new controllers based on optimal-control theorem and the conventional controller. Through simulations and experiments, an optimal servo with feedfoward for a helical motor has the best performance compared with the others.