Research On Posture Analysis And Trajectory Planning Of Six Degrees Of Freedom Robot

Trajectory planning is one of the key technologies for intelligent control of six-degree-of-freedom robots.The traditional posture control method that keeps the motion posture the same as the initial posture may cause the robot joint motion to be out of range.At the same time,the motion trajectory planning method in a multi-obstacle working environment is complicated.In view of the above problems,this paper proposes a trajectory planning method based on spatial position and posture analysis in a multi-obstacle working environment.The inverse kinematics model is derived from the spatial position;all the reachable poses of the spatial position are analyzed;the selection criterion of the optimal pose is proposed;the obstacle avoidance strategy for real-time collision detection is established;the multi-obstacle working environment is planned by the simulated annealing algorithm The trajectory of the motion;completed the motion simulation and experimental verification in the multi-obstacle working environment.The main contents of the thesis research are as follows:First,the kinematic model of the ABB irb120 robot is derived.The Modifeid-DH parameter method is used to derive the robot’s forward kinematics model,and the inverse kinematics model of the robot is derived using analytical and geometric methods,respectively,and the correctness of the positive kinematics model and the inverse kinematics model is verified.The Jacobian matrix of the robot is derived based on the vector construction method,which is used as the mathematical basis for the optimal pose selection in robot pose analysis.Secondly,the robot pose analysis method and the optimal pose selection method of space position points are proposed.Based on the mapping relationship between the spherical point on the spherical surface serving the spherical surface and the joint angle of the robot,a pose ball representing the pose set of the position point is preliminarily established.A spherical area aggregation method for dividing different types of spherical points is proposed,and a pose ball representing the pose set of different areas is obtained.According to the joint motion range of the robot,the numerical method and the analytical method are used to analyze the attitude set of different spherical areas,and the attitude ball at the position point is further obtained.The comprehensive performance index of the robot with the best posture is studied,and the robot posture is solved only based on the spatial position.Then,a collision detection algorithm and trajectory planning algorithm in multi-obstacle working environment are proposed.Based on the spatial position-based attitude solution method,the interference discrimination method between the spatial position of the connecting rod and the obstacle is studied.Using the stretching change of the cubic B-spline curve,a segmented path planning method under multi-obstacle environment based on simulated annealing algorithm is proposed.Based on the spatial position-based attitude solution method,the motion attitude of the motion track point is obtained.According to the fifth-degree B-spline curve,the joint angle,velocity and acceleration between the trajectory points are planned.The robot motion parameters of the traditional attitude control method and the attitude control method in this paper are compared and analyzed,and the effectiveness of the proposed method is verified.Finally,the simulation and demonstration of the robot motion experiment under multi-obstacle environment is completed.The upper computer program is written,and the simulation analysis is carried out in Robotstudio to verify the correctness of the upper computer program.The experimental procedure was designed to complete the movement of the irb120 robot in a multi-obstacle environment.