Characteristic And Experimental Study Of A Redundant Actuated Delta Parallel Mechanism

In recent years,with the improvement of automation in industrial production lines,parallel robots have received extensive attention due to their advantages of high speed,high precision,and high load capacity.As an important method to improve and solve the problems of conventional parallel robots,redundant drive is of great significance to the improvement of automation.This paper systematically studies the influence of redundant drive on the traditional Delta parallel mechanism,and theoretically proves that the redundant drive plays an important role in improving the mechanism performance.Firstly,a redundant actuated Delta parallel mechanism configuration is proposed to meet the functional requirements and design requirements of robots determined by the background of laboratory theoretical research.And the degree of freedom is calculated,which shows the rationality of the configuration.A system power scheme that directly drives the geared motor is designed to meet the requirements of compact structure and small size.According to the functional requirements of the robot,the servo gear motor and electrical hardware system are selected and matched.The specific design and 3D modeling of the structure of the mechanism was completed using ProE software.Then,the kinematics and dynamics analysis of the redundant actuated Delta parallel mechanism was performed.Analytic expression of position equation is obtained by analytical geometry method.The velocity and acceleration model is established by deriving the velocity Jacobian matrix of the mechanism based on the closed vector derivation method.According to the lumped mass physical model and Lagrange multiplier method,the dynamic inverse model is established.And the redundant drive force is analyzed by the least square method.Then,based on the velocity Jacobian matrix,the kinematics and statics problems of the redundant and non-redundant Delta mechanisms of the same structural size parameters are analyzed.The numerical simulation results of workspace,operability,Jacobi condition and static transfer relationship are compared and analyzed,which intuitively illustrates the advantages brought by the introduction of redundant drive to the conventional Delta mechanism.Finally,the redundant drive Delta parallel mechanism experimental platform is built.An open distributed control system is arranged based on the CAN bus to ensure the reliability and lower cost of the system.The system test and simple motion control experiments verify the rationality of the overall design of the mechanism and the effectiveness of the control system.