Research On Robot Polishing Compliance Control Method Based On Force Feedback

At present,in China,the finishing stage of complex curved parts is mainly based on manual polishing,however,manual polishing has common problems such as poor consistency of processing quality,low processing efficiency,poor working environment of workers and shortage of skilled workers.This is an urgent need for robotic automated processing technology instead of manual work.During the actual polishing process of the robot,the robot trajectory is generated according to the 3D model of the workpiece.Due to the inevitable error between the 3D model and the actual workpiece,and the positional accuracy of the robot itself,the actual motion trajectory of the robot is inconsistent with the ideal trajectory,which leads to the phenomenon that the robot does not contact or over-contact during the polishing process.At this time,it is necessary to coordinate the position control and force control of the robot through the compliance control.At the same time,the size of the polishing contact force directly determines the quality of the polishing.For this reason,this paper studies the robotic polishing compliance control method for the constant force control problem in the robot polishing process.This paper briefly describes the main research methods and research status of robotic compliance control at home and abroad.Combining the complex surfaces such as bathroom hardware as the processing object,the robot polishing compliance control system based on KUKA robot and force sensor is built.Develop a technical route for robotic polishing compliant control systems,and the communication network between the computer and the robot and force sensor was established.Robot polishing compliance control is mainly used to achieve constant contact force during robot polishing,so the solution of contact force is very important.By establishing the gravity compensation algorithm of the end load of the robot,the interference of the gravity factor on the solution of the polished contact force is eliminated.Based on the theoretical design,the effectiveness of the algorithm is verified by experiments.On the basis of gravity compensation,the contact force solution scheme based on the base coordinate system and the tool coordinate system is proposed for different machining conditions.The mathematical model of the robot polishing system is the premise of the compliant control.According to the system identification principle,the recursive least squares method and the Kalman filter algorithm are used to identify the polishing system,and the mathematical model of the polishing system is established.The design of the controller is the core of robotic compliance control.According to the flexible control model of system identification,the basic PID controller is optimized by fuzzy control and RBF neural network.Using MATLAB to simulate and adjust the parameters of the designed controller,and verify that the two control methods can effectively achieve the constant contact force during the robot polishing process.