Research On Kinematics Optimal Parameters Of 4R Manipulator Based On Trajectory

In recent years,the development of science and technology strides forward and more and more industrial robots are applied in industrial production.Especially in the automatic logistics production line,the multi joint robot is the most universally used.This thesis is concerning with the optimal mechanism parameter study based on 4R Manipulator for loading and unloading.The following parts are included in this paper:Firstly,the research background and the purpose and significance of this paper are introduced.Development research status of industrial robot at home and abroad,research status of kinematics analysis,trajectory planning and parameter optimization are also introduced,which can lay the foundation for the research in this paper.According to the actual production needs,mechanism of the manipulator is selected,and then basic structure and the manipulation task of the manipulator are confirmed.Secondly,based on the work principle of robot for loading and unloading,the kinematics equation is established by using the D-H method,and this equation is verified.The inverse solution is solved by using the counter transformation method.On the base of it,the selection principle of the inverse solution is discussed.Thirdly,several methods of the trajectory planning design are introduced in this thesis.Based on the inverse kinematics solution and the attitude of the end effector of the manipulator,the joint angles of the manipulator at the critical positions are calculated.Then,according to the velocity constraint and time distribution of the joints,the three polynomial interpolation method is used to plan the trajectory of the manipulator.Then,according to the motion trajectory of the manipulator and some known mechanism parameters,in this paper,the method of “the shortest path ”as the objective function,which makes the whole robot system consumes the minimum energy.The mathematical model about the mechanism parameters of motion analysis and the reasonable range of the mechanism parameters as constraints are selected.In the manipulator feeding process,optimal mechanism parameters are obtained in the key points and on the motion trajectory.Finally,the simulation experiment based on trajectory planning is verified by the MATLAB software,and the trajectories of the manipulator before and after the solving the optimal mechanism parameters are simulated in MATLAB software.The error of bothtrajectories in the same coordinate system is obtained,and the rationality of the error is analyzed.The results show that the optimal mechanism parameters are effective and have important reference value to optimize the structure design of manipulator.