Dynamic Analysis And Motion Control Research Of Four-degree-of-freedom High-speed Parallel Robot Mechanism

This paper combines the high speed and light load carrying task demand of automatic production in areas such as electronic,food,medicine,modern logistics,ect.Taking a kind of new high-speed parallel robot mechanism with single moving platform and parallelogram branched chain as research object,which can realize SCARA movement.The research is funded by the National Natural Science Foundation Project(item no.51605225)..The research including the concept of the mechanism design,kinematics analysis,dynamics modeling,servo motor parameter estimates,trajectory planning and motion control system development,The following results are mainly achieved:In terms of conceptual design and kinematics analysis,realizing the rotation of z axis by adding the hinge of rotation of z axis on the three parallel branched chain,.the new mechanism is proposed with single moving platform and can realise SCARA motion.Compared with high speed parallel mechanisms with double platform,.the new mechanism can effectively simplify the structure of the moving platform,reduce the quality of the moving parts,which is conducive to to realize the dynamic characteristics of high speed and high acceleration.Based on this,the forward and inverse position model and Jacobi matrix of the mechanism are established by vector method,and the singularity analysis of the mechanism is completed too.It is concluded that the mechanism can avoid the occurrence of singularity when the moving platform adopts non-square structureIn the aspects of dynamic modeling and parameter estimation of servo motor,the model of velocity and acceleration of each moving component is established first,and then a complete dynamics model is established based on virtual work principle.Based on the characteristics of high-speed parallel mechanism,simplified the dynamics model.based on the peak torque,the parameters of servo motor are estimated and selected.In the aspect of trajectory planning,the effects of different motion rules and motion paths on the end platform motion and active joint motion are studied.Based on the time optimality and the principle of motion stability,the motion rule optimization and motion path planning are completed.In the aspect of the development of motion control system,the motion control hardware and software system have been set up based on the development of prototype.The forward and inverse position model,path interpolation planing,motor shaft enable,mechanism homing,interpolation,stop and reset functional block is developed,through the electromechanical joint adjustment,realised high-speed and high-accelation movement in the work space.