Trajectory Planning For4-DOF Manipulator Based On Optimal Torque

Manipulator, which can complete the space docking, unknown exploration, satellite maintenance, and other complex tasks, plays an important role in aerospace engineering. The Control of manipulator is particularly important in these occasions, moreover, trajectory planning is the basis of the control. This paper mainly studies the motion planning, trajectory planning, and error analysis of the4-DOF sample manipulatorThe4-DOF sample manipulator kinematics model is derived by using the D-H method, and simulation analysis for the manipulator is conducted. On this basis of motion planning for the manipulator, the minimax method is adopted to optimize the six selected possible maximum torque according to its light weight, flexible and poor load capacity, aiming to withstand the maximum torque of the shoulder. The optimization results determine the specific point of the rotary joints for every action and the optimal torque. The results meet the design requirements. Then the whole operation process of the manipulator is simulated in SolidWorks to verify the motion planning.On the basis of the motion planning, maximum acceleration indicator of the joints in different conditions is formulated by taking the mechanical properties and the operating characteristics of the manipulator into consideration. Sine curve is used as the interpolation function of the joints trajectory planning. The maximum dynamic torque and angular velocity of the joints in different conditions are obtained. The results show the time to complete all the tasks.Finally, on the basis of the kinematic analysis, the homogeneous transformation matrix method is used to derive the functional relationship between the manipulator’s D-H parameter error and the end-actuator error. The error indicators is formulated by calculating the errors of the manipulator’s key action to meet the design requirements. At last, simulation under specific law of motion and given error condition is taken to analysis the change of end pose and error using Matlab and the simulation is verified based on ADAMS and MATLAB.