Energy-optimal Trajectory Planning For A 7-DOF Robotic Manipulator Based On Improved Wolf Pack Algorithm

With the improvement of robot technology,the application of robotic manipulator in the field of industrial automation production is gradually increasing.In order to reduce the production cost,the actual production puts forward higher requirements on the operational energy consumption of industrial robotic manipulators.In this regard,this paper takes the seven-degree-of-freedom robotic manipulator as the research object and studies the trajectory planning of the robotic manipulator from the perspective of energy consumption,and the main research contents are as follows.(1)The joint structure model of the seven-degree-of-freedom robotic manipulator is established,and the positive kinematic analysis is performed.For its redundant characteristics,the inverse kinematic problem is solved by the analytical-geometric method,and the inverse solution geometric expressions based on the joint structure model are derived in detail.The Newton-Euler method is used to establish the kinetic equations,and the kinetic model of the robotic manipulator is established.(2)For the robotic manipulator trajectory optimization problem,this paper proposes to adopt the wolf pack algorithm with well global search performance for the optimization.Based on the traditional wolf pack algorithm,the problems of its convergence speed and search step length are studied,and the improved wolf pack algorithm based on information interaction mechanism and adaptive step length is proposed.The improved wolf pack algorithm is compared with other algorithms using nine test functions,and the results show that the improved wolf pack algorithm performs better in terms of convergence speed and global search.(3)For the problem of point-to-point operation of redundant robotic manipulator in obstacle environment,the parameterization method of the optimal energy consumption trajectory planning problem is proposed.The method converts the trajectory planning problem of the redundant robotic manipulator into a parameter preference problem by analyzing the mathematical model based on the construction of six times polynomial trajectory,and realizes the motion trajectory planning of the robotic manipulator in the joint space.In order to reduce the energy consumed during the operation of the robotic manipulator,a kinetic-based energy consumption mathematical model is established as the objective function of parameterized optimization,which considers the physical constraints of the mechanism and the obstacle constraints in the operation space,so that the robotic manipulator can complete the operation task while satisfying the constraints and achieving the optimal energy consumption of the trajectory.(4)Simulation and verification of the trajectory planning method of the seven-degreeof-freedom robotic manipulator are conducted with two sets of point-to-point tasks.By analyzing the trajectory of each linkage,the angle,angular velocity and angular acceleration of each joint with time,the trajectory planning method is verified to meet the constraint requirements.By comparing the total energy consumption before and after trajectory optimization,it is verified that this energy consumption trajectory optimization scheme can effectively reduce the energy consumption during the operation of the robotic manipulator.By evaluating the optimization algorithm of trajectory energy consumption model,the effectiveness of the improved wolf pack algorithm compared with the traditional wolf pack algorithm for trajectory optimization is verified.