Position Sensorless Position Control for Dual Solenoid Actuator

This study aims to realize a compact actuator system. Solenoid actuators have some advantages such as low cost and high output with small volume. Additionally, the structure is simple, therefore the size can be easily miniaturized. In general, the solenoid actuator can generate the driving force in only one direction, hence a spring is necessary to return the position at the initial position. To realize quick motion, dual solenoid actuators (DSA) which can generate the driving force in both directions are studied. In this study, sensoeless technique is used to realize further miniaturization of the system. This paper proposes position sensorless position control for DSA. In the proposed control, a disturbance observer is used to achieve robust position control. The control performance was confirmed by experiments. As a result, the position was completely followed to 0.1 Hz sinusoidal command. The frequency characteristics of the proposed control were measured. The proposed control can achieve that the gain is from 0 dB to 1 dB and the total harmonic distortion is less than 10 % when the frequency is up to 5 Hz.