Sliding Mode Control Study Of Permanent Magnet Linear Motor Direct Thrust Control System

In recent years, the direct thrust control system is becoming the research hotspot in the field of motor control due to its simple structure, quick thrust response, and the robusabiltiy to rotor parameters. However, the linear motor is sensitive to load disturbance and system parameter change, and the end effect of linear motor is difficultly controlled. Hence, the study on linear motor control system with high control accuracy, easily realized and strong robustness has important practical significance.Firstly, the structure model of permanent magnet linear motor direct thrust control system has been established. And then, this thesis has considered the design of controller and speedless-sensor. The main research results are as follows:(1) By integrating sliding mode control technique and RBF neural network, a novel RBF neural sliding mode controller has been designed, which can adapte the variation of parameters and improve the robustness of system. The simulation results have verified the effectiveness of the proposed controller.(2) Aiming at the chatter phenomenon of sliding model control, this paper has proposed a speed loop controller based on the reaching law of sliding mode control.It has been shown from the simulation results that the present controller can not only effectively eliminate the chatter phenomenon, but also restraine the load disturbance, reducethe speed overshoot, and improve the speed of tracking.(3) This paper has designed a speed-sensorless based direct thrust controller for permanent magnet linear motors, which removes the requirement on the speed-sensor. Simulation results have illustrated the effectiveness of the present controller in the accurate and quickness.