Research On Optimization Strategy Of Mobile Milling Robot Operation Accuracy

With the development of aerospace technology,the core cabin components of the spacecraft is developing toward large-scale,new claim of the high-precision and efficient manufacture of large spacecraft cabins was posed.Mobile robot can realize the large parts nonstructured machining.Industrial robots have high repeatability,but absolute position accuracy is low.In the continuous machining process,the precision of the machined surface of the workpiece is low,and the tolerance requirements cannot be met.It is necessary to study the improvement of the working accuracy of the robot.For the mobile milling robot,the robot system is studied from three levels to face the accuracy of the robot operation and the improvement of machining efficiency.The main research contents of the paper are as follows:(1)For the problem of low absolute position accuracy of the robot,the main sources of analysis of the position error are geometric error and joint rotation error.Based on the theory of robot kinematics,the error model of the robot is established.The grating ruler is used as the joint rotation measuring device to compensate the parameter error to improve the absolute position accuracy of the terminal.(2)For the problem of mobile station positioning in the working area,the image visual servo control theory is adopted to meet the docking positioning requirements of the terminal relative to the target.The laser ranging sensor is used to realize the distance positioning of the mobile robot relative to the target.(3)Using a dual robot cooperative control method,a control system is simultaneously controlled to control the cooperative control of two industrial axes with a total of 19 motion axes,satisfying the online detection and processing requirements of the milling robot,and improving the processing efficiency of the milling robot.Based on the mobile milling robot for kinematic error compensation,external sensor servo position control and dual robots cooperative motion test verification.The research results show that under the combined influence of error compensation strategy and external sensor servo positioning control,the average trajectory accuracy of the optimized mobile milling robot reaches 0.104 mm,and the robot's "online detection & machining" is realized through the coordinated motion control of the dual robot system",improve the processing efficiency of mobile robots,and provide an effective solution for the unstructured processing of large components.