Identification of Transfer Function of Position Servo System

In the three closed-loop servo system, the position loop is the key consideration object, and the transfer function directly reflects the relationship between the position instruction signal and the feedback signal. Because the servo system contains controller, motor, mechanism, control algorithm, and so on, the whole system is more complex, and all kinds of coefficient constant cannot be obtained accurately, so it is difficult to obtained transfer function accurately by modeling and simulation method. In order to improve the identification accuracy of the system transfer function, the amplitude-frequency and phase-frequency data are obtained by experimental method, and the algorithm program is written by MATLAB. The algorithm can identify the system transfer function quickly and accurately, and can achieve the identification accuracy that the absolute error of amplitude-frequency characteristic and phase-frequency characteristic is very small. It has great practical value for the research of servo control system.