Research On Energy-optimal Trajectory Planning Method Of Industrial Robot

Industrial robots are widely used in various industrial scenes due to their efficiency and high performance. Many of them are operating in the manufacturing stage of the production line where the highest percentage of energy is consumed. Therefore, their energy consumption bec ame a major focus for many robots manufacturers and academic research groups. Trajectory planning is one of the industrial robots optimal control problem s, the task of trajectory planning is to plan the smooth optimal trajectory via given path points, which satisfies relevant boundary constraint conditions. In the process of the optimal trajectory planning, the energy optimal trajectory is easier to track and the stress of the actuators and the operating arms can be reduced. This paper treats the common serial industrial robot with six degree of freedom as the research object, respectively to study the Cartesian coordinate continuous trajectory of industrial robot method to select the optimal trajectory of energy consumption a nd joint space energy consumption per unit period spot welding robot, the optimal trajectory planning method.First of all, the model of Motoman HP165 type industrial robot was established based on D-H notation and the robot kinematics theory. The solutions of forward kinematics and inverse kinematics were derived after kinematics equation was proposed based on the analysis of D-H parameters.Secondly, robot dynamic equation was established based on Lagrangian Formulation by using the theory of multiple rigid body dynamics knowledge and the robot model was set up in MATLAB. The energy consumption model of robot trajectory was established by using the relationship between permanent magnet AC servo motor electrical parameters and the joint torque. The trajectory of the manipulator end-effector was described by using Frenet-Serret formula in the Cartesian coordinate space and then the trajectory was transformed into joint space by kinematic inverse solution. Take the straight line and circle-arc trajectory of the end-effector as an example, the optimal energy consumption trajectory was discussed on the condition of the multiplicity of the kinematics inverse solution.Lastly, in order to obtain the optimal energy trajectory, the energy consumption mathematical model of spot welding robot trajectory driven by PMSM was established. The method for searching for the optimal spot welding robot trajectory based on Bee Evolutionary Genetic Algorithm was put forward by taking consideration of the constraints of robot ki nematics, dynamics and the production cycle. In order to ensure the early global optimization and late stage convergence speed of the algorithm, the selection operator was improved and the nonlinear algebraic fitness function was proposed. Finally, the pose of typical spot welding robot was designed by the software of DELMIA and relevant algorithm was verified by MATLAB simulation. By contrast with the shortest time trajectory optimization, the results indicate that energy consumption of the energy optimal t rajectory was significantly reduced in the case of meeting the constraints.