Abstract

Info

Author(s):: FANG Cheng; HU Zhi; School of Electronic and Electrical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China

Keywords:: force tracking; adaptive impedance control; force overshoot avoidance; accelerated convergence; model predictive control

Abstract:: This study explores how the robotic arm in a dual-arm surgical robot-assisted system stretches soft tissue, and specifically discusses the issue of force control optimization during the stretching. To address the force error challenges posed by non-linear stiffness changes in soft tissue contact, adaptive impedance control scheme is adopted, which combines with an online adaptive strategy to adjust impedance parameters and reference trajectories. The trajectory accuracy improvement through an estimator based on Lyapunov function and impedance parameter adjustment through model predictive control enable the robot to void real-time force overshoot and improve the force convergence speed during the stretching. Experimental results show that the proposed control strategy successfully avoids force overshoot and accelerates force convergence during real-time contact. The proposed approach supports precise force control during soft tissue surgery and lays a foundation for future clinical applications.