An automatic control of robotic polishing  for a compound surface composed of a plane and curved parts

Abstract

Abstract The presented paper proposes a robotic polishing method for compound surface composed of plane and curved parts to increase quality, reducing cost, time and effort compared to manual polishing. The polishing approach is adopted based on the smooth trajectory planning, constant force algorithm, and modeling the removal profile depth. In order to generate a smooth polishing path that helps in stability and accuracy of motion during the polishing operation, a cubic B-spline interpolation curve with the harmonic model approach and Squad method were used. An online stiffness and reverse damping force (OSRDF) impedance controller supported by gravity compensation algorithm is used to to achieving a constant polishing force. Consequently, to evaluate the quality of a polishing results, the removal depth model is determined for plane and curved surfaces before and after polishing. The experimental studies were conducted to polish the manufactured box composed of resin material using the UR robot manipulator for validating the proposed method. The results of experiments proved the constancy of polishing force thanks to the OSRDF impedance controller with a small fluctuation directly proportional to the value of applied force. It also showed accurate equality of removal depth at the applied force of 20 N. The overall results explained that a presented polishing approach has a good capability to polish a compound surface with shiny appearance after painting.