Adaptive impedance control for robotic polishing with an intelligent digital compliant grinder

Abstract

Aircraft-engine blade has a free-form surface in space, which is extremely complicated. And the surface milling must be polished completely to eliminate the surface residual texture and stress concentration. To solve this problem, an intelligent digital compliant grinder with active and passive compliance, double-end floating and multi-station polishing is independent-designed. Besides, a novel impedance controller based on particle swarm optimization algorithm is proposed, which can realize adaptive adjustment of the impedance parameters. And it can maintain the contact force between the grinding tool and the workpiece to a constant value. The experimental results show that the proposed method works well and the surface roughness and the machining consistency of the blade are greatly improved with the intelligent digital compliant grinder for active contact force. Specifically, the surface roughness of the blade reduces from 0.730 μm to 0.065 μm, and the force fluctuation is less than 1 N, therefore, leading to a better surface quality.