The constant force control based on an optimized environmental model for the robotic lapping of curved surface

Abstract

During the curved surface lapping processing by robot, the surface quality of the processed workpieces cannot be fully guaranteed because of the uncontrollability of lapping contact force. Therefore, the accurate control of the contact force between the tool and the workpiece is important to improve the processing quality. This paper proposes an impedance control strategy based on an optimized environmental model to address the serious constraints brought by the uncertainty of the environmental model in impedance control on the compensation accuracy of contact force, and constructed a contact environmental model of elastic abrasives based on neural network algorithm, which improved the compensation accuracy of contact force through iterative iteration and prediction between the environmental model and the impedance model. Through comparison experiments, it is found that compared with the unoptimized method, the force control tracking error is reduced by 60.9%, the contact force variance is reduced by 25.7%, the contact force error during curved surface force control lapping process is reduced by 58.3% and the contact force variance is reduced by 52.5%, and the workpiece roughness Ra value is reduced by 37.2%. Therefore, the robotic constant force control system based on optimized environmental model can achieve a better force control effect, which can realize accurate and stable control of contact force during curved surface lapping process by robot, and has certain potential for engineering application.