Sensorless Position Control for Compact Dual Solenoid Actuator Using Disturbance Observer

Abstract

This study aims to realize a tactile display which can represent 2D haptic information on the display surface. The tactile display typically consists of a lot of compact linear actuators. In order to represent the haptic information on the display, the motion of the actuator should be controlled. The position sensor is usually attached to the actuator to derive the position information. However, the sensor makes the system large and expensive. Therefore, the sensorless control technique is effective to reduce the size and cost. In our previous works, a position estimation method for a compact dual solenoid actuator was proposed. In this paper, the position control with the estimated position feedback is proposed. Additionally, a disturbance observer is applied to achieve robust position control. The frequency characteristics of the sensorless position control was experimentally investigated. The results indicated that the sensorless position control was accurately achieved when a sinusoidal position command whose frequency was less than 2.0 Hz was applied. This proposal is useful since the compact actuation system is realized.