Research On Trajectory Optimization For HSR-605 Robot

In recent years,due to the flexible,intelligent and efficient working performance,industrial robots have been widely used in various automated industrial production fields such as welding,painting,grinding,palletizing,handling,etc.Therefore,as the basis of industrial robot in motion control research,the trajectory planning algorithm has received increasingly attention.Because the existing industrial robot only considers its kinematic constraints while planning trajectory,this paper studies the trajectory optimization algorithm with dynamic constraints based on HSR-605.Firstly,kinematics model was carried out for HSR-605 robot.The forward kinematics of the robot is established by the standard DH parameter method.Next,based on the piper criterion,the closed-object method is used to solve the eight inverse kinematics problem and the kinematics model is validated.According to the joint attribute configuration algorithm,the joint properties are divided based on the three singular configurations of the robot with the singular point problem in the inverse solution process effectively avoided.Secondly,for the trajectory planning problem of robots,the trajectory planning methods of Cartesian space and joint space are studied respectively.For the problems such as singularity and redundancy of the trajectory planning in Cartesian space,the trajectory planning problem is transformed into joints space.To Analyze the torque constraints in the trajectory planning process,the inverse dynamics model of the HSR-605 robot with analytical expression is studied.Then the time-optimal trajectory planning algorithm based on HSR-605 robot is studied with joint torque constraints.For the nonlinear optimal control problem,by introducing parameters and fitting the mapping relationship between joint angle and parameter with the least square method,the time-optimal trajectory planning problem based on kinematics and dynamics constraints was transformed into convex optimization control problem.The cubic spline curve was used to describe the velocity variable of the parameter space to ensure the continuity of the acceleration and the joint torque,then the problem was transformed into SOCP and solved.Finally,the path planning in Cartesian space was carried out in InteRobot2018.The validity of the time-optimized smooth trajectory algorithm was verified based on the original algorithm.