Research On Application Of State Observer In Servo Control System

With the rapid development of power electronic technology,micro-compter technology,rare-earth permanent magnetic materials and the control theory, permanent-magnet synchronous motor(PMSM) has been widely used in motion control system with low or medium capacity. However,the permanent-magnet synchronous servo system is easily influenced by factors such as the changing parameters of the electrical machine, the disturbing effect from outside load and the sensor noise ect. People have to do some research on the advanced control strategies and control methods in order to acquire the high performance and low cost permanent-magnet synchronous servo system which has strong adaptability and the capacity of anti-disturbing. This paper is mainly centered about the research on high performance and low cost permanent-magnet synchronous servo system.The mathematics model of the permanent-magnet synchronous motor (PMSM)in d-q reference frame is established , and the PMSM vector control strategy is analyzed and then the control method rotor field-orientation vector control of i d=0 is chosen. According to the automatic control theory, the components and the mathematics models of the permanent-magnet synchronous servo system are analyzed in detail, in accordance with the engineering design method of automatic control system adjustor ,the current loop and the velocity loop are designed. In order to meet the needs of rapid dynamic respond and at the same time ,make the system has the strong ability of anti-disturbing and restraining the sensor noise, The state observer is introduced in the control system, the current loop state observer and the velocity loop state observer are set up respectively, by these means, the parameters such as the feedback current,position, velocity and the load torque can be estimated in advance. Based on these, The simulink design on the whole system under the simulink circumstance is proposed in this paper. In the simulink design, the relationship between the system's dynamic performance and the parameters of the system adjustor and state observer are discussed detailedly; further more, how the adjustor and state observer's parameters can influence the sensor noise are analyzed; the solving methods in system control are presented.The performance comparisons between the systems using digital filter and the state observer are given. The experimental results show that the system using the state observer has more excellent quality in tracking and anti-disturbing.