Research On Dynamic Performance Analysis And Control Of An 8-SPU Parallel Robot

With the progress of science and technology,industrial robots have been widely developed,among which the development of the series mechanisms are most rapid.Due to their strong load capacity and high motion precision,parallel robots have been gradually applied in the assembly of auto parts.In order to make the parallel robot better serve the automotive industry and strengthen the development of industrial robot,it is necessary to design and study the parallel robots with excellent comprehensive performance.Therefore,this paper takes 6-DOF 8-SPU parallel mechanism as the research object,analyzes the inertia match problem of parallel robot,estimates the parameters of the servo motor,completes the type selection of the motor,and through the analysis of institutions dexterity and servo motor control research,achieves good dynamic performance and control performance of parallel robot.The main contents of the thesis are as follows:Firstly,the kinematics and dynamics models of parallel robot are established,and the inertia matrix of parallel robot is deduced.A method for calculating the equivalent inertia parameters considering the coupling effect between branch chains is proposed.Based on the mechanical resonance frequency and acceleration torque of the parallel robot,the inertial matching problem of parallel mechanism is analyzed.Aiming at two practical problems in the design of the motion system,the inertial matching principle is proposed.Secondly,according to the principle of virtual work,the inverse dynamic equation of the mixed rigid body is established.Based on singular value decomposition,the parameter estimation model of the servo motor is established.The validity of the method and the rationality of the selected motor are verified by a prototype example.Then,under the workspace,the evaluation indexes of kinematic dexterity and dynamic dexterity are proposed respectively.Based on MATLAB software,the kinematic dexterity and dynamic dexterity are simulated.Through multi-objective optimization,not only the optimal size parameters of the mechanism are obtained,but also the optimal dexterity of the mechanism is achieved in the optimal parameters,that is,the working ability and dynamic performance of the parallel robot are given full play.Finally,the principle of PMSM servo control system of 8-SPU parallel robot is introduced from the angle of current loop and position loop.The vector control of i_d(28)0 is used.The auto-disturbance theory is introduced into the position loop controller,and the simulation model of the servo system is established by MATLAB.The SVPWM algorithm is adopted to track the rotation angle and torque of the motor,which establishes the foundation for the design and optimization of the control system of the 8-SPU parallel mechanism and provides the theoretical foundation for the practical control of the 8-SPU parallel robot.This thesis analyzes the 8-SPU parallel mechanism from many aspects,which provides certain theoretical reference for the analysis and design of the parallel robot applied in the automotive industry,and has certain engineering significance for the field of industrial robot to improve the machining accuracy,reduce the manufacturing cost and realize automation.