A Servo System Identification Method Based on Relay Position Feedback Phase Trajectory Curve Fitting

Abstract

The invention discloses a servo system identification method based on relay position feedback phase trajectory curve fitting, which relates to the fields of servo motion control and the like. The method is realized based on relay feedback technology and optimal curve fitting, and its realization steps are as follows: setting experimental parameters and relay parameters; conduct relay position feedback experiments, record displacement and velocity data to obtain the actual phase plane trajectory; set the initial value of the cost function parameter; perform curve fitting and correct the initial value of the parameter according to the fitting result until the fitting curve and the actual curve Consistent; determine the servo system model and its parameters. The present invention can avoid the disadvantage that the least squares method requires acceleration information for servo system identification, does not have the approximation problem of frequency domain identification based on the description function method, can obtain higher identification accuracy with less servo system information, and has short running time, The advantages of easy on-site implementation and flexible debugging process provide a basis for improving the motion performance and system reliability of the servo system.

Description

technical field [0001] The invention relates to the technical field of motion control, in particular to a servo system identification method based on relay position feedback phase trajectory curve fitting. Background technique [0002] With the development of manufacturing and control technology, the servo system with the potential of precise speed and position control is widely used in modern industry and plays the role of the control core. However, the accuracy of the servo system is limited due to factors such as external interference and friction. Some methods to improve the control accuracy of the servo system, such as compensators and model-based controllers, have been widely used, but most of these methods are based on high-precision servo systems. Therefore, the high-precision servo system identification method has attracted the attention of many developers and designers in the field of control. [0003] Servo system identification methods can be divided into two ca...

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Problems solved by technology

[0004] After searching the existing literature, it is found that the Chinese patent application number is 200910051179.2, the name is "AC servo system self-tuning method based on relay feedback" and the Chinese patent application number is 201010131841.8, the name is "Servo system control method based on relay feedback ", this technology uses the description function method to identify the parameters of the servo system, and designs a PID controller, which achieves a good control effect. However, due to the error caused by the approximate processing of the description function method, the model identification accuracy of the controlled servo system is limited. limit

In the literature "A Relay Shaping Method for ServoMechanical System Identification" (a filter shaping servo system identification method), C.Liu et al. proposed a shaping and filtering method, which makes the output of the relay module closer to a sine wave by shaping and filtering the output of the relay module. Thereby reducing the approximation error and improving the description function method. Although this method can effectively reduce the approximation error and improve the identification accuracy, it increases the workload of designing the filter.

[0005] After searching, it was found that J.Liu et al. proposed a relay speed feedback-based Time domain characteristics, this method can avoid the approximation error of the description function method, but there is the influence of the quantization error of the speed feedback

The Chinese patent application number is 201310647691.X, titled "A Servo System Identification Method Based on Time Domain Characteristics of Relay Position Feedback". The approximation error of the description function method, but still only to obtain some characteristics of the limit cycle through the relay feedback experiment, there is a problem of low data utilization

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