Bilateral force sensorless control based on finite‐time adaptive sliding‐mode‐assisted disturbance observer

Abstract

Bilateral teleoperation systems are widely used to compensate for image spin and in many other applications. Good transparency (position tracking and force feedback) is an important performance index in the control design of bilateral teleoperation systems. This study aims to achieve good transparency for teleoperation systems using force sensorless by proposing an alternative to direct force measurement. Our proposed method is a finite‐time adaptive sliding‐mode‐assisted disturbance observer, which combines disturbance observer with adaptive sliding mode control. The finite‐time stability of adaptive sliding‐mode‐assisted disturbance observer is analysed using the Lyapunov theory. Moreover, a bilateral control law based on adaptive sliding‐mode‐assisted disturbance observer is designed. The proposed method not only improves the system transparency with both force feedback and position tracking, but is also chatter‐free. Experiments are conducted using bilateral brushless DC motors in an experimental setup to demonstrate the effectiveness of the proposed method.