Research On Improvement Of Positioning Accuracy Of Robot Based On Laser Tracker Measurement

Industrial robots are being used more and more in aircraft digital assembly at present, and the robot technology improves the efficiency and quality of aircraft assembly greatly. By connecting various aircraft components, system parts and templates of drilled holes in the end, a robot can fulfill various accurate positioning and reduce assembly auxiliary equipment. By fixing multi-function tools, the robot can finish many functions such as drilling a hole or boring a hole, and this improves the digital level and quality of aircraft assembly greatly. Although the industrial robot has a high repetitive positioning accuracy, the positioning accuracy is influenced by its structure and it can’t meet the requirement of high accuracy in assembly. It is necessary to introduce the laser tracker to carry out a high accurate and wide-range measurement in order to improve the positioning accuracy of the robot and meet the requirement of assembly installation. So it is very important to carry out the research on improvement of positioning accuracy of robot based on laser tracker measurement in order to expand the application of industrial robot technology in aircraft digital assembly and to improve the assembly quality and the level of flexibility. The aircraft digital assembly is the research background of this article, and this article makes a research on improvement of positioning accuracy of robot based on laser tracker measurement. Specific contents of each chapter are as follows:In chapter1, the research and application status of aircraft digital assembly with laser tracker and industrial robot at home and abroad are introduced firstly, and then laser tracker technology and robot technology are summarized, in the end of this chapter the background and overall framework of this dissertation are given. In chapter2, the system structure of laser tracker, measurement principle and the software of measurement are introduced firstly, then, the orientation principle and error of measurement are analyzed, and at last the kinematics of KUKA robot is calculated. In chapter3, joint link parameters of KUKA robot are selected as the optimized parameters, and the optimized model is established, then Newton method is selected as the optimized method, and simulation demonstrates that results of optimization accord with practice, with optimization the positional accuracy of robot can be improved greatly. In chapter4, a method based on laser tracker measurement to calibrate the tool coordinate frame of robot is put forward, and the principle and process of calibration are expounded; however, the accuracy of calibration is not always stable, so the singularity of the robot is analyzed and that the calibration error of robot TCF arises when the robot runs through its singular positions is proved, and then experiment is carried out to test and verify. In chapter5, in aircraft digital assembly, the structure, function and calibration of coordinates of robot processing operating system is stated, on this base, a method based on laser tracker measurement to correct the position and orientation of robot is put forward, and the principle and process of the method is given, then the technology of position and orientation correction integrated with system software is introduced. In the final chapter, summary for the whole work is given, and the future work is expected.