A Feedrate-Force Planning Algorithm Considering the Hybrid Dynamic Constraints of the Robotic Compliant Grinding System With Active Force Control

Abstract

Robotic-compliant grinding with force control is widely used to enhance the surface quality of complex parts. The dynamic characteristics of the robot and the end-effector affect the tracking accuracy of the feedrate and contact force, while existing methods often overlook these dynamic effects. Therefore, a feedrate-force planning algorithm considering the hybrid dynamic characteristics of the robot and force-controlled end-effector is proposed for compliant grinding. First, the mapping relationship between feedrate and grinding force is analyzed using the material removal depth (MRD) model, and a time-optimal feedrate planning model based on B-spline feedrate profile is established. Second, the hybrid dynamic constraints are established by analyzing the dynamic characteristics of the robot and the response characteristics of the force-controlled end-effector, which is based on a series elastic actuator. Finally, optimized feedrate and grinding forces satisfying the hybrid dynamic constraints are obtained by adjusting the control points of the B-spline. Experimental results demonstrate that the proposed algorithm achieves feedrate-force planning while satisfying the hybrid dynamic constraints of the robotic grinding system. Compared to the existing methods, grinding tests show that the proposed method substantially improves the coordination accuracy between feed rate and force, thereby reducing MRD error and surface roughness.