Research On Constant Force Grinding Control Technology Of Industrial Robot

Industrial robot grinding is widely used,but there are still some problems to be solved.In this paper,the key technology of constant force grinding control of industrial robots is studied,and a constant force grinding control system is developed by combining the key technologies and algorithms such as admittance control and gravity compensation.Finally,the constant force index is achieved and the surface quality of test pieces is improved.The main content of the paper is as follows:First of all,in order to ensure the smoothness of the grinding force,the grinding trajectory is reasonably planned.The optimized trajectory is obtained through the study of the cutting method,the analysis of the critical overlap region and the curvature analysis of the machining curve.By using the transformation principle of coordinate system,the orientation of the optimized trajectory grinding point is obtained.Secondly,the least square admittance control strategy is improved to keep the force constant.The fuzzy control strategy is analyzed and the effectiveness of the improved method is verified by step signal simulation.At the same time,the weight compensation of end-effector and the normal offset algorithm of robot displacement are introduced,and the accurate offset data of normal pure contact force and robot base coordinate system are obtained respectively.Thirdly,a constant force grinding system was developed to verify the effectiveness of the admittance control grinding method under the fuzzy strategy.The system includes the main robot equipment,software framework,force value acquisition and processing module,force position conversion module,real-time robot pose acquisition module,etc.Finally,by using the trajectory planning method,a reasonable trajectory of the curved surface is generated by RobotStudio simulation software.In the developed constant force grinding control system,the admittance control method based on least square and fuzzy strategy was used to carry out constant force grinding experiments respectively.After comparison,it was found that the goal of reducing the force fluctuation and reducing the surface roughness of the specimen was achieved,which verified the effectiveness of the method proposed in this paper.