RBF Neural Network Sliding Mode Control For Single Electromagnetic Suspension Guiding System Of Linear Elevator

Linear elevator vertical transportation system which is applied the high-rise building in the future high-rise elevator is an important direction of development. The electromagnetic levitation technology applied the linear elevator guide shoes compose electromagnetic guiding system of linear elevator, making linear elevator in the shaft with no mechanical friction, high-speed operation, eliminate the noise and reduce the vibration when the car is running. As the electromagnetic guiding suspension system of linear elevator exist parameters uncertainty and disturbance, leading to suspension gap is unstable. Therefore, this paper propose RBF neural network sliding mode controller is used to suspension air gap height control of single electromagnetic suspension guiding system, ensuring the system stability and tracking performance.This paper reviews the background for magnetic levitation technology for development-oriented and describes recent research in electromagnetic levitation guiding technology of linear elevator. Meantime, the control method of levitation guiding technology is briefly introduced. The single electromagnetic suspension guiding actuator used 3U-type electromagnet. The structure of the guiding system is "Eight-Maglev" symmetrical topology structure. The mathematical model of single electromagnetic suspension guiding system is established, based on the structure of guiding actuator and the principle of electromagnetic levitation. In order to solve the nonlinear characteristics of the model, the method of linear equilibrium is used to simplify the mathematical model of the single electromagnetic suspension guiding system. According to the linear model, the levitation air-gap controller is designed. In order to overcoming the effect of system parameter variations and external disturbances,sliding mode controller and dynamic sliding mode controller is separately designed to control the single electromagnetic suspension guiding system. By comparison, the integral sliding mode control and dynamic integral sliding mode control suspension air gap in the system parameters change adapt better to the suspension air gap height than the traditional PID controller. The dynamic sliding mode control reduced the jitter of the system. However, little jitter of dynamic sliding mode control could cause the vibration of elevator car, when the elevator car is running. In order to effectively restrain the still existing jitter, use RBF neural network sliding mode control to speed up the system response speed and reduce the dynamic sliding jitter. The elevator car achieved a steady state.By comparing Matlab simulation results of the four control methods discussed above, RBF neural network sliding mode control can achieve the suspension of air-gap height robustness of single electromagnetic suspension guiding system.