Research On 6R Assembly Manipulator Time-pose Optimal Trajectory Planning And Comprehensive Accuracy

As the main working equipment of major equipment manufacturing industry, heavy-duty precision manipulator is widely used in automobile, shipbuilding, aerospace, large machine tools and metallurgy of iron and steel industry. These industries need heavy-duty precision manipulator has good performance, the most important indicators of manipulators are high efficiency and high precision. "High efficiency" means shortest time to complete the specific work tasks or task route in order to shorten the manufacturing cycle and improve work efficiency; "High precision" refers to high movement precision and positioning accuracy in the process of manipulator working, in order to improve the quality of finished products. The two exist as a unity, so the research on the trajectory planning of heavy-duty precision manipulator requires to consider the effect of optimization problems and accuracy. This subject comes from the project of National Natural Science Fund(project number:51375519), the six DOF assembly manipulator was research object, using screw theory as the foundation, established the optimization objective function by using the method of weighted coefficient and studied the time-pose drift optimal trajectory planning model of manipulator. Further to analyze comprehensive precision of manipulator to acquire the influence of each parameter on the manipulator accuracy, finally the perturbation motion principle was used to the precision compensation of manipulator.The main research work of this paper are as follows:(1) In order to improve the precision of assembly manipulator, comprehensively analyze and research on the static precision and dynamic accuracy of manipulator, deformation caused by the influence of error on the manipulator accuracy considering the structure error and transmission error and mechanical hand connecting rod, the static precision of the model and the dynamic precision models are established, finally on the establishment of the manipulator comprehensive precision model based on the screw theory, analyzed the influence of various factors on the accuracy of the law.(2) In order to improve the assembly manipulator’s working efficiency and accuracy, based on the end position acquired by precision research, aimed at assembling manipulator specific target working state, established time-pose drift optimal trajectory planning model. Based on the kinematics analysis to the screw theory as the foundation, considering the kinematic constraint condition, the weighted coefficient method was used to define objective function of the model. The influence of global optimum and local optimal was considered in the process of model optimization, using the penalty function method to solve the problem, and finally the optimal trajectory was obtained by simulation analysis.(3) According to the various factors affecting the static and dynamic accuracy of manipulator, aimed at error on the manipulator caused by each of the factors, the perturbation motion principle was used to compensate the error and the compensation model was established. The method of error compensation was specifically described, and finally verified by simulation and theory, thus greatly improve the precision of a assembly manipulator.