Research On Trajectory Planning And Motion Control For A 4-DOF Serial Manipulator

With the sharp decrease of the working-age population and the increasing cost of labor,the demand for upgrading and transformation of traditional manufacturing industry is increasingly urgent.The intelligent equipment,represented by industrial robots,has shown excellent features that traditional equipment can hardly reach in terms of improving equipment automatic level,increasing production efficiency,and ensuring the best quality of products.Manipulators are widely applied in industrial production and plays a more and more important role due to its outstanding operating ability,which is of great practical significance in promoting the transformation and upgrading of traditional manufacturing industries.This paper is to study the servo control system and trajectory tracking method of the manipulators so as to make progress in improving the manipulator's operating accuracy and the stability of the control system.The main content of this paper is as followings:(1)Hardware system design.Hardware system and master-slave control system for the four degree of freedom manipulator based on EtherCAT bus is built up in this paper.The hardware system uses the ET1100 slave control board based on EtherCAT bus combining with the DSP to drive the DC brush motor to improve the communication speed of the manipulator control system and lay the foundation for the trajectory tracking experiment platform.(2)Kinematics analysis of manipulator and trajectory interpolation.The kinematics model of the four degree of freedom manipulator is established based on homogeneous coordinates,and the inverse kinematics solution of the manipulator is obtained by geometrical method.Moreover,based on the inverse kinematics solution,a cubic polynomial is used for interpolation in order to get a steady trajectory for the point-to-point movement of the manipulator.(3)Research on manipulator trajectory tracking algorithm.Lagrange method is adopted in this paper to establish the dynamic model of the manipulator.Solidworks and Adams is utilized in the simulation to verify the correctness of the dynamic model.In order to improve the computational efficiency of the trajectory tracking algorithm and shorten the calculation time,the first two joints with the largest load coupling of the manipulator is simplified to a two degree of freedom linkage model.Then,the RBF neural network adaptive control is applied to simulate the trajectory tracking of the two degree of freedom linkage model,so as to verify the practicability of the method.(4)Establish the experimental platform as is illustrated in(1)and test the performance including servo control,communication speed and synchronize precision.