Research On The Tracking For Suspended Following Objects System

The tracking control system of suspended following objects is an on-earth low gravity simulation device which has important application,it can be used for special engineering operations such as spacecraft maneuvering,landing simulation and astronauts low gravity training.Because the system has higher requirements on control precision,and the friction coefficient of the viscous term in the system is extremely small,so the system is not easy to converge,which poses a high challenge to design the control method for the system.The tracking control system of suspended following objects is focused on in this paper.The effective control and measurement methods are studied.The main research contents of the thesis are as follows:In order to solve the problem of inaccurate measurement of sling swing angle caused by the fact that the reflector can't be installed vertically with the sling manually in the measurement link of the tracking control system of suspended following objects.A dynamic measurement method of sling swing angle based on dual redundant PSD autocollimator is proposed.This method can iteratively solve the relevant parameters of the measurement system by the least square method to obtain more accurate sling angle measurement values.Finally,the simulation verification of the measurement system is completed by the simulation platform designed in this paper,which proves the effectiveness of the designed system.Aiming at the stabilization control problem of the tracking control system of suspended following objects in the stop experiment stage,an observer-controller design method is proposed.Firstly,the model of T-S fuzzy form is obtained based on the system kinematics and dynamics equations.Then the system observation error equation is obtained through the fuzzy observer combined with the problem that the state variables such as velocity and angular velocity are unmeasurable in the system.To utilize the membership functions more effectively,fuzzy system's membership functions formed vector is used as new premise variables.Without considering the Lipschitz conditions constraints,the error terms which are induced by unknown premise variables are decoupled into a new T-S fuzzy system.Then,the stability condition of the augmented error system is obtained by using Lyapunov function.A conversion method from BMI to LMI is designed,which is converted into LMI condition,and the gain matrix of the observer-controller is obtained.Finally,the simulation platform designed in this paper is used to verify the control task in the system stop experiment stage,and the effectiveness of the designed control algorithm is demonstrated.In order to solve the problem that the real system design cost is too high,so a simulation system for the tracking control system of suspended following objects is developed.The system is formed by connecting upper and lower computers through network communication.The lower computer is developed based on Eclipse environment of Linux system and is mainly composed of system module,observer module,controller module,measurement system simulation module and data transmission module.The upper computer is developed based on the Qt Creator environment of Windows system and is mainly responsible for human-computer interaction and data transmission.By using the designed simulation platform,the simulation analysis of the results described in chapter 2 and chapter 3 can be completed.