Research On Motion Planning Method For Multi-robot Coordination

At present,the industrial production process is becoming more and more complex,and the performance characteristics of the robot working independently cannot meet the actual production requirements.Therefore,the research on multi-robot technology is increasingly important and meets the needs of current social development.Multi-robot technology has many difficult problems worthy of study,such as how to achieve the coordinated movement of multi-robot to complete the given production tasks;how to plan the trajectory to make the robot finish the given production tasks efficiently and so on.Therefore,this paper takes the related technologies involved in coordinated motion of multi-robots as the research object,analyzes the motion constraint relationship,and designs the time-optimal trajectory planning algorithm,so as to make multi-robot coordinate movement efficiently.The specific research contents are as follows:Firstly,the mathematical model of single robot is established.The improved D-H method is used to establish the geometric model of the robot,and the homogeneous transformation matrix is derived to represent the position and attitude relationship between the adjacent coordinate systems of the robot;in the inverse kinematics modeling of the robot,the first three joint angles are solved by the geometric method,the last three joint angles are solved by the Euler transformation method,and the final joint angle value is selected according to the principle of the shortest travel;the Newton-Euler recursion equation is used to build the dynamic model of the robot,and the simulation program is written to verify the correctness of the established model.Secondly,the related technologies of multi-robot coordinated motion planning are studied.In this paper,the algorithm of indirectly calculating and calibrating the base coordinate system of multi-robot is designed,and the process of selecting points is optimized.The orientation transformat ion matrix between the common target coordinate system and the base coordinate system of multi-robot is solved,and then the orientation transformation matrix of the multi-robot base coordinate system is derived.When a robot's motion trajectory is given,another robot's motion trajectory can be generated according to the constraint equation.Thirdly,the time-optimal trajectory planning algorithm based on dynamics is designed.Given the motion path of the robot hand in Cartesian space,the path is discretized,the Cartesian space coordinates of each discrete point and the differential about the path length are calculated;the dynamic constraint,the joint velocity constraint,the space line velocity constraint and the attitude angular velocity constraint are considered,the upper limit value of each discrete point's velocity is calculated recursively according to the linear programming principle;the maximum acceleration of each discrete point is calculated recursively,and then the velocity of each discrete point is calculated and kept within its own constraint range;the corresponding time of each discrete point is calculated by using velocity,and then the path position,orientation of Cartesian space and joint parameters of each period are output according to the interpolation period.Finally,a multi-software co-simulation experiment platform is built.On the simulation platform,the calibration experiment of multi-robot base coordinate system,the experiment of multi-robot motion coordination and the experiment of time-optimal trajectory planning algorithm based on dynamics are carried out.The experimental results prove the correctness and accuracy of the algorithm designed in this paper,and then achieve the fast and accurate coordinated motion goals fo r multi-robot.