Research C-shaped Gantry Parallel Machine Tool Calibration

In order to improve the motion precision of machine moving platform in real time,kinematic calibration of the3-(2SPS) parallel mechanism with redundant driving is to be mainly researched in this paper. That is the main driving force transmission of C-Type gantry machine tools.Firstly, by introducing the geometric structure of parallel mechanism,the direct and inverse kinematics solution is established. And according to analyze of the ideal and actual model of mechanism,the kinematic model of single chain is set up by using D-H matrix method.Secondly,a directly pose measurement method based on additional measurement shaft is put forward,according to the kinematic characteristics of institution.it is used to be established the pose measurement model of moving platform. And based on that the error of the measurement system and measuring accuracy of the encoder are researched.Thirdly, in order to establish the main error source model,the error factors that affect the motion precision of machine moving platform are analyzed. Then the parameter identification method of telescopic rod and redundancy slider are given. That is used to identify actual geometry parameter of the institution by using the nonlinear least square method.Finally, the data of calibration experiments is to be simulated by using matlab.the results show that the actual geometry parameter can be identified effectively,motion precision can be improved and calibration effect is good.