Visual Servo Control of the Macro/Micro Manipulator with Base Vibration Suppression and Backlash Compensation

Abstract

This study investigates the visual servo control of the space station macro/micro manipulator system. The proposed approach is based on the position-based eye-in-hand visual servo (PBVS) and takes advantage of the hardware sensors to overcome the macro manipulator’s base flexibility and joint backlash. First, a vibration suppression approach based on the reaction force feedback control is proposed, the deflection forces are measured by the six-axis force/torque sensor at the base of the micro-manipulator, and damping is injected into the flexible base in the closed-loop control to suppress the base vibration. Second, the small changes of joint backlash are compensated based on the macro manipulator joint angles sensor and converted to the desired motion of the payloads. Finally, PBVS with the lag correction is proposed, which is adequate for the precise positioning of large payloads with significant low-frequency oscillations. Ground micro-gravity experiment implementation is discussed, simulations and experiments are carried out based on the equivalent 3-DOF flexible base manipulator system and the macro/micro manipulator ground facilities, and results demonstrate the effectiveness of the proposed control algorithm.

Backlash compensation based oscillation suppression control for automatic loading manipulator arm with nonlinear extended state observer

“…Backlash is a pervasive issue that impacts various industries, including aerospace [8], CNC machine tools [9], military-industrial agglomerations [10], robotics devices [11], medical rehabilitation [12], wearable exoskeletons [13], and hydraulic servo systems [14]. It is widely acknowledged that backlash significantly hampers control systems' performance.…”

Backlash compensation based oscillation suppression control for automatic loading manipulator arm with nonlinear extended state observer

“…This poses additional challenges, as the fundamental parameters of the backlash are often unknown, making the system handling even more complex. Backlash is a pervasive issue that impacts various industries, including aerospace [8], CNC machine tools [9], military-industrial agglomerations [10], robotics devices [11], medical rehabilitation [12], wearable exoskeletons [13], and hydraulic servo systems [14]. It is widely acknowledged that backlash significantly hampers control systems' performance.…”