Electric Three-degree-of-freedom Movement Platform Analysis And Modal Control

Compared with the series mechanism,the parallel mechanism has high bearing capacity,high movement accuracy.The object of this paper is a new type of three-degree-of-freedom parallel mechanism.This novel mechanism is studied from the aspects of kinematics forward and inverse solutions,dynamic analysis,structural parameter optimization,load matching,control strategy research,and experimental verification.The constrained equations were used to analyze the concomitant motions.The kinematics inverse solution of the three-degree-of-freedom parallel mechanism was studied by combining the constraint equations and the vector method.The virtual prototype was built in ADAMS and the MATLAB was cosimulated to verify the correctness of the inverse kinematics solution.The kinematics forward solution was deduced using the characteristics of the mechanism,and the kinematics positive solution was verified by simulation.In order to study the influence of the anti-twist arm position parameters on the system concomitant motion,based on the kinematics relationship,a genetic algorithm was used to study the anti-twist arm position parameters.In order to study the dynamics of the platform,Kine's equations were used to model the dynamics of the three-degree-of-freedom parallel mechanism.The generalized inertial force and the generalized main force were derived.So the kinetic equations were obtained.On the basis of kinematics and dynamics,the range of motion and the load of the actuator of the three-degree-of-freedom parallel mechanism are calculated.Based on this,we can select electric cylinder model.In the control strategy,the joint space control commonly used in kinematics control strategy is first studied.The control method uses PID control.The results show that the kinematic control strategy can follow the signal well,but because of the complexity of the mechanism,there is a certain coupling.This forms a way to use the modal space control method to control the decoupling space.It can improve the system control performance.Simulated software was used to analyze the control effect of modal space control.Design and build experimental prototypes,use the rapid control prototype technology to complete the communication function of the Ether CAT network;verify the kinematic control strategy on the experimental prototype;analyze the system with the sweep signal at the same time,observe the response,and obtain the various poses Direction of bandwidth.Due to the limitation of communication,only the position control experiment can be completed and the modal space control effect cannot be verified.