Research On The Trajectory Planning Methods Of Redundant Dual-arm Robots

With the acceleration of the global automation process,people have put forward higher requirements for robots,not only in industrial production,but also hope that robots can be integrated into our lives,especially in the home service industry,to help the elderly reduce the burden of life.Compared with traditional single-arm robots,redundant dual-arm robots have a wide range of applications,large working space,good fault tolerance,and can perform secondary optimization of kinematics and dynamics.Therefore,it has become one of the hot topics for scholars at home and abroad.In this paper,a redundant dual-arm robot is taken as the research object,and two aspects of time optimal trajectory planning for dual-arm loose coordination operation and the real-time collision avoidance trajectory planning for dual-arm tightly coordination operation are mainly studied.First of all,the kinematics and dynamics analysis of the redundant dual-arm robot of the research group is performed.Based on the link parameters of the redundant manipulator,the kinematics model of the redundant manipulator was established using the D-H method,and the forward and inverse kinematics of the redundant manipulator were solved on this basis;Mathematical model of redundant dual-arm robot was established by Matlab/Robotic Toolbox,and the work space of dual-arm coordinated operation was analyzed based on Monte Carlo method;and the coordinated operating space of the dual-arm robot is analyzed.A Newton-Euler iterative dynamics algorithm was used to establish the dynamic model of the redundant manipulator.Secondly,to solve the problem of time optimal trajectory planning for a given path point during the loosely coordinated operation of a dual-arm robot,this paper uses a hybrid particle swarm optimization algorithm to plan the trajectory of the robotic arm.The trajectory planning of the adjacent nodes of the joints of the robotic arm is performed using the fifthdegree polynomial interpolation method.The minimum of the sum of the trajectory running time intervals of each segment is used as the objective function,and the angular velocity,angular acceleration and driving torque of the joints of the robotic arm are used as constraints.using the hybrid particle swarm optimization algorithm to optimize the running time,so as to plan the running trajectory of each joint.Then,in view of the safety problems of redundant dual arm robot in the process of coordination operation,this paper proposes an algorithm based on the self motion characteristics of redundant dual arm robot to coordinate operation of real-time self avoiding collision and simultaneously avoiding environmental obstacles.According to the kinematic constraint relationship of the coordinated operation of the two arms,the kinematic equation of the dual-arm is constructed,and the dual-arm are simplified by the capsule surrounding simplification algorithm.The shortest distance between the center of the environmental obstacle and the axis of the connecting rod of the master and slave manipulator and the shortest distance between the axes of the connecting rod of the master and slave manipulator are obtained in real time by the gradient projection method.At the same time,the "threshold distance" is introduced to assess the danger of collision between the obstacle and the robotic arm,so as to change the speed of the nearest point on the robotic arm in real time,so that the movement of the robotic arm avoiding the obstacle is continuous and stable.Finally,in order to verify the effectiveness of the algorithm proposed in this paper,an experimental platform is built to simulate and experiment the algorithm that the redundant dual arm robot cooperates to operate real-time self collision avoidance and simultaneously avoids environmental obstacles.