Application Of 6-RSS Parallel Mechanism On Active Control Of Six Dimension Vibration Absorber

Multi-dimensional vibration absorber based on the parallel mechanism is the new idea and the new breakthrough in the multi-dimensional vibration domain,has the important application prospect and the development value.A 6-RSS parallel mechanism is used as the main mechanism of six-dimension vibration absorber bemuse of its advantage on simple structure,the compact type,the high precision, easy-to-control and so on.This dissertation studies the application of the 6-RSS mechanism on active control of large amplitude low frequency multi-dimensional vibration.And the key technology of the vibration absorber system is studied carefully. The main research works can be described as follows.The dynamics model of the main mechanism of six dimension vibration absorber is achieved by Newton-Eular method.In order to ensure the accuracy of the model,the moving platform inertial,branched-chain inertia and other factors are considered deeply. Through the numerical simulation,the correctness and the accuracy of the dynamic model of the main mechanism are verified.As the six dimension vibration absorber is a complex mechanical and electrical systems,between the structure parameter and the controlled variable,the coupling phenomenon is existence.To enhance the performance of the vibration absorber,the parameters of the vibration absorber system are designed by the integrated optimal design of structure and control system.By simulation,the validity of this method is proved.Considering the effect of the time delay of the system,the measurement kinematical model of the base platform center is built to obtain exact states values of the center involves displacement,velocity,acceleration based on kalman filter theory.The influence of measuring instrument error and unknown disturbance to the system is considered fully in the model.The effective and the rationality of the model are analyzed from different aspects by simulation.Finally,the pose of the base platform center is predicted ahead of time.A robust auto-disturbance rejection controller in linkspace is developed to accomplish the high precision vibration control of the six dimension vibration absorber. Genetic algorithm is used for setting the controller parameters,a necessary condition of the controller stability is given,and the good compensation capability of the controller for friction disturbance is proved by simulated.This paper proposed compound control strategy to realize the active vibration isolation of six dimension vibration absorber.The numerical simulation results showed this method may effective suppress the influence of the vibration to moving platform pointing accuracy.