Research On Motion Planning Of 7-DOF Robot Arm Based On Self-motion

Robot autonomous motion planning technology is the key technology for rapidly applying robots to practical production.This paper is developed under the research fund for the doctoral program of higher education named “the Bilateral Servo Control Strategy of tele-operation of electro-hydraulic underactuated redundant robot”(No.20130061110009),and key issues of avoiding joint limit,motion planning,and collision avoidance is investigated.In this paper,the kinematics parameters of Kuka LBR iiwa robot with zero offset are used as models,and the kinematics equation is established according to D-H parameter method.According to the solution of the inverse solution,the workspace is divided and the controlling parameters of the inverse analysis are provided for the motion planning.The relationship between the arm-angle and the joint angle is established,and the intersection of the interval is solved,and the arm-angle interval satisfying the limit of the seven joints can be solved quickly.The 3D visualization obstacle environment model is established and provides the function of collision detection for line segment,triangle plane with obstacle model.The algorithm of the intersection of the hollow spindle and the obstacle formed by the self-motion of the robot is established,and the arm-angle interval of the obstacle avoidance is obtained.The interval intersection of arm angle between the obstacle avoidance and the joint limit avoidance is obtained,which can be used as the complete range of the subsequent dynamic optimization.Based on the combination of RRTstar and BiRRT,a connection strategy based on sample evaluation index is proposed,which makes the result more favorable to the global optimal path.The bidirectional heuristic random sampling strategy is used to bias the sample point to the starting point target point to improve the sampling probability of the narrow channel near the optimal path.