Back-Stepping Sliding Mode Improved Master-Slave Control For H Platform Driven By Linear Motors

The H-type movement platform studied in this thesis is composed of three Permanent Magnet Linear Synchronous Motor(PMLSM)with the same structure and parameters.Two linear motors are installed in parallel on the Y-axis to simultaneously push the linear motor on the X-axis to move in the Y-direction and the linear motor itself on the X-axis to move in the X-direction.However,the motion of the linear motor on the X axis leads to the uneven force of the two linear motors on the Y axis and coupled with the mechanical coupling between the two motors,both of them can lead to the single-axis position tracking error and synchronization error of the H-type movement platform,which not only affects the working accuracy,but also leads to system damage and even personal safety.Therefore,the study of the single-axis control method and the synchronous control method is very important for the H-type movement platform.The purpose of this thesis is to design a single-axis position controller to ensure the accuracy of the single-axis position,and to design a synchronous controller to reduce the two-axis synchronization error of the H-type movement platform.Firstly,the development status of H-type movement platform at domestic and abroad,and the factors affecting the control accuracy of H-type movement platform and the research status of control strategy are understood.The decline of H-type movement platform position accuracy caused by the single-axis position tracking error and the synchronization error,and when the linear motor motion on the X axis move along the X-direction to produce twist force to affect two linear motor on the Y axis,so mathematical model of H-type movement platform is deduced according to the torque balance equation and the basic principle of permanent magnet linear synchronous motor.Secondly,an integral back-stepping adaptive sliding mode control method is proposed to solve the problem of single axis tracking error.The sliding mode control rate and adaptive rate of the system are firstly designed,then the Lyapunov function is designed to prove the stability of the system.At the same time,the traditional parallel master-slave control is used in the two-axis synchronous control,and the designed integral back-stepping adaptive sliding mode control is compared with the ordinary sliding mode control.The simulation of the designed controller is performed by using MATLAB/Simulink.Finally,in order to further reduce the influence of uncertainty and other factors on the position accuracy of the single-axis motor,a recurrent neural network was designed to estimate the lumped uncertainty of the system,and a robust compensator is designed to solve the problem of minimum reconstruction error in the system.The design of recurrent neural network to estimate the uncertainty of the system can solve the influence of uncertain disturbance on the system.An improved master-slave control is proposed to reduce the synchronization error between the two axes much effectively.MATLAB/Simulink is used to simulate the designed controller and analyze the results.