Research On Control Strategies And Experiments Of The Servo System Of Permanent Magnetic Synchronous Linear Motors

Comparing with rotational motors, permanent magnetic synchronous linear motors (PMSLMs) have wide application foreground in many fields such as high speed and high precision numerical control, precision measurement because of their advantages of high speed, high precision and big thrust force. In this paper, models of the servo system of PMSLMs are built, control strategies of current, velocity and position are proposed and the force disturbances existing in the servo system of PMSLMs are compensated. At the same time experiments are made to verify the performance of the servo system.Firstly, models of the servo system of PMSLMs are built, which include those of electromagnetics and kinematics, the optimization method of the structure of PMSLMs is proposed, and force disturbances of servo system are analyzed. All these models will be the bases of the software development of servo system.Research on the current control strategies that can realize the precise control of currents is important because it will influence the whole performance of the servo system. According to the analysis of the effect and generation mechanism of position angle error, a position correct technology based on model reference adaptive control method is proposed to promote the control precision of currents. On the whole, the decoupling technology of the vector control algorithm, the position angle correction and sinusoidal space vector Pulse-Width-Modulation (SVPWM) control technologies are used to improve the control performance of current, which results in good effect.After the current control strategy is proposed, velocity and position control strategies are proposed. In the velocity control, fuzzy control method is used, at the same time a disturbance observer is applied to suppress the force disturbances of PMSLMs considering the disadvantages of fuzzy controller. In the position control, the complete position control strategy with disturbance suppression technologies is proposed,and an improved neural network is proposed to offline approximate the force ripple based on the features of the force ripple, which results in better effect. At the same time, a robust adaptive controller is designed to make the servo system be robust to the parameter variation since the parameters of the servo system are time-varying.It is described comparatively detailedly that the design and realization of the software and hardware of the servo system of PMSLMs based on the double CPUs which are industrial control computer and DSP.In the end, simulation and experiments are made to verify the proposed control algorithms. At the same time, test methods and results of positioning precision, maximum velocity and other performances are provided to further verify the whole performance of the developed servo system of PMSLMs.