Dynamic Modeling And Control Of The Cable-Driven Parallel Robots

The cable-driven parallel robots(CDPRs)are a kind of special parallel structure robots with flexible cable instead of rigid connecting pole,it has the advantages of large working space,fast movement speed and easy disassembly,which makes it have a broad application prospect and important research and development value.This paper has studied kinematics analysis,dynamics modeling,control strategy and dynamics parameter identification research for the cable-driven parallel robots,the main contents are as follows:Based on the vector closure theory and differential derivative rule,the kinematic inverse solutions of position,velocity and acceleration of the cable-driven parallel robots are analyzed,the kinematics inverse equations are derived.The Archimedes spiral trajectory of the end-effector is planned,and the changes of the cable length,the cable length velocity and the cable length acceleration is analyzed.Considering the cable elasticity,the dynamic analysis of the cable-driven parallel robots is carried out,the dynamic model of the end-effector and actuator unit is established by using the Newton-Euler method,and the dynamic model considering cable elasticity is obtained by using the Lagrange method.The minimum p norm of correlation force was selected as the objective function to optimize the cable tension.The accuracy and necessity of the elastic dynamics model are verified by simulation.Dynamics model of the cable-driven parallel robots as basis,design the force/position hybrid control strategy,using expanded critical proportion method on the controller parameter setting,the force/position hybrid control strategy is analyzed under the condition of different velocity control of the cable-driven parallel robots,results show that the force/position hybrid control strategy can effectively control while guarantee the trajectory tracking and cable tension,high precision motion control can be implemented successfully.The control system of the cable-driven parallel robots is designed and built.Based on the system dynamics model of the cable-driven parallel robots,the linear equation of the dynamics parameters to be identified is derived,the dynamics parameters of the robot system are identified by the least square method,and the validity of the dynamics parameters identification method is verified by Matlab and Adams software simulation comparison.