Research Of Robotic Grinding And Polishing Key Technology For Freeform Surface

At present,the polishing process of complex curved surface parts in our country is mainly based on manual operation,processing quality is difficult to be effectively guaranteed.It is time-consuming and inefficient,and most of the working environment is not suitable for workers to operate.So the intelligent and automatic surface finishing is an important link in the process of achieving high quality,high efficiency and low cost.This paper mainly focuses on the key technologies of intelligent robot automatic polishing system for complex curved surface.The main research contents are summarized as follows:1)Automatic compliance polishing system of complex curved surface robot was established.a flexible polishing tool was developed,the compliant characteristics of the polishing tool structure can imitate the human hand to carry on the processing,and overcome the contradiction between the rigidity and the flexibility of the robot.2)The distribution of flexible disk and curved surface contact pressure was analyzed,and the relative linear velocity distribution of the flexible disk polishing region was theoretically deduced and the theoretical equation of the polishing material removal profile was derived based on mobile polishing material removal index and the micro integral principle and the influence regularity of main process parameters on material removal profile of curved surface is analyzed.The method of the the row cutting and the ring cutting in the path planning of the robot end polishing tool was introduced,through the analysis and comparison,it is more suitable for the automatic polishing process of complex curved surface,such as spacing scanning path.3)In robot motion space,the pose of polishing end tools was described,the robot coordinate system transformation and mechanical analysis of flexible disk and gravity compensation algorithm were introduced,A simplified model for the contact between the end polishing tool of the robot and the outside environment was established,and the control strategy of the force based on the position inner loop was introduced in detail.4)The robot polishing system software was introduced and its performance was tested,the test results show that,constant pressure grinding and polishing was basically realized,control accuracy in ± 3N~5N,the experimental study on the surface of NAK80 die steel was carried out by using a self-developed polishing system,the resultsshow that the roughness of Ra=0.025 m,basic closest mirror effect fully meet the actual needs,the feasibility and effectiveness of the automatic high precision polishing of complex curved surface robot is well proved.