Position‐based force tracking adaptive impedance control strategy for robot grinding complex surfaces system

Abstract

As a key technology of robot grinding, force control has great influence on grinding effects. Based on the traditional impedance control, a position‐based force tracking adaptive impedance control strategy is proposed to improve the grinding quality of aeroengine complex curved parts, which considers the stiffness damping environmental interaction model, modifies the reference trajectory by a Lyapunov‐based approach to realize the adaptive grinding process. In addition, forgotten Kalman filter based on six‐dimensional force sensor is used to denoise the force information and a three‐step gravity compensation process including static base value calculation, dynamic zero update and contact force real‐time calculation is proposed to obtain the accurate contact force between tool and workpiece in this method. Then, to verify the effectiveness of the proposed method, a simulation experiment which including five different working conditions is conducted in MATLAB, and the experiment studying the deviation between the reference trajectory and the actual position is carried out on the robot grinding system. The results indicate that the position‐based force tracking adaptive impedance control strategy can quickly respond to the changes of environmental position, reduce the fluctuation range of contact force in time by modifying the reference trajectory, compensate for the defect of the steady‐state error of the traditional impedance control strategy and improve the surface consistency of machined parts.

Constant Force Grinding Controller for Robots Based on Soft-Actor-Critic Optimal Parameter Finding Algorithm

“…Therefore Guilian Wang et al proposed an adaptive variable impedance control algorithm with pre-PD adjustment to discover the soft grinding and polishing of complex surfaces and the stability and convergence of the force control algorithm were proved by comparative experiments [5]. Lun Li, based on traditional impedance control, proposed a position-based force-tracking adaptive impedance control strategy to improve the complex surface grinding quality of aero engine parts grinding quality of aero-engine [6].…”