Research On Continuous Path Smoothing Trajectory Planning And Time Optimization Of 6R Industrial Robot

As one of the ten key areas formulated by the "Made in China 2025" strategy,industrial robots have been widely used in all walks of life,especially in precision manufacturing industry,such as flattening of welded parts,deburring of cast parts,and deburring of stamped parts.Industrial robots tend to move along a given continuous path,which requires industrial robots not only to run stably,but also to have the shortest running time to meet the high quality and high efficiency of the manufacturing industry.Therefore,in the trajectory planning of the continuous path,proper trajectory planning and time optimization is crucial to the efficient,accurate,and reliable operation of the industrial robot.In this paper,the HY1006A-144 6R serial industrial robot was taken as the research object.In view of the stability of the continuous path trajectory and the trajectory planning accuracy of industrial robots,a modified three Bézier trigonometric interpolation function method was used to plan the presupposed continuous trajectory of 6R industrial robots on the basis of kinematics.At the same time,the rationality of this method in trajectory planning was verified by dynamics.On this basis,the operation time of the robot was optimized with the constraint of the motion parameters and torque,which provides a certain reference value for the trajectory planning and optimization of the continuous trajectory.The main research contents of this paper are as follows:(1)According to the structural parameters of 6R robots,the improved D-H method was used to establish its kinematics equations.The kinematics of the robot was analyzed by using forward kinematics and inverse kinematics,and the inverse solution of the robot was obtained by analytical method.(2)In view of the disadvantage of singularity in trajectory planning in Cartesian space,we chose the trajectory planning for 6R industrial robot in joint space.Firstly,for the problems of low-order polynomial acceleration mutation and high-order polynomial operation difficulty,the quintic polynomial and the cubic B-spline interpolation curve was used for trajectory planning respectively.After analyzing the advantages and disadvantages of the above two trajectory planning methods,the improved cubic Bézier trigonometric interpolation function was selected for trajectory planning of the robot.Secondly,the trajectory simulation was performed by using the spatial straight line and the spatial circular arc as the specified paths.The results show that using the cubic Bézier trigonometric interpolation function for trajectory planning is the most ideal in terms of the stability of the trajectory and the precision of the trajectory motion.(3)To further verify that the cubic Bézier trigonometric interpolation function method is a reliable and stable trajectory planning method,the dynamic equation of the HY1006A-144 industrial robot was established by using the Lagrangian method.And the dynamic simulation was analyzed in ADAMS.The results show that each joint torque curve of the robot is relatively smooth without mutation,and they are within the specified torque range,which verifies the rationality of the trajectory planning method.(4)In order to meet the requirements of high efficiency,the purpose of this thesis is to optimize time,with both motion parameters and moments as constraints.And on the basis of the straight path of the trajectory planning of the cubic Bézier trigonometric interpolation function,the genetic algorithm is used to optimize the time.Finally,the time of the trajectory planning is reduced from the first 15 seconds to 9.99 seconds,and the optimization rate reaches 33.4%.