Variable Parameter Modeling And Compensation Technology Of Servo System

As servo systems are more and more widely used in industrial manufacturing equipment,people have put forward higher requirements on their control accuracy.Reducing the tracking error of a servo system is one method to improve the control accuracy.Because the inertia affects the dynamic performance of a servo system and is unstable,this paper establishes a variable parameter transfer function model of the servo system that can detect the variation of the inertia,and a tracking error online compensation scheme based on the model is proposed.Firstly,this paper analyzes the servo system loop by loop,establishes the overall model of the servo system and simplifies it appropriately,and analyzes the rule of the inertia change with the load mass change.By analyzing the relationship between the inertia and the parameters of the servo system transfer function model,a variable parameter transfer function model of the servo system is proposed.Finally,according to the model,the main source of the tracking error is analyzed.Secondly,in order to establish a variable parameter transfer function model that can reflect the inertia variation of the servo system,the paper introduces the recursive least squares method with a forgetting factor.Base on this,an online identification method of the inertia of the servo system is designed.Thirdly,by studying the compensation mechanism of the iterative pre-compensation scheme,it is found that this scheme cannot adapt to the change of inertia in the real world.In order to solve this problem,the variable parameter model of the servo system is used to combine with the iterative pre-compensation scheme,and a tracking error online compensation scheme is proposed based on the variable parameter modelFinally,a motion control experiment platform was built based on Twin CAT platform,and the simulation and experiment compensation were carried out using the experiment platform and Matlab software.Through the parameter identification experiment,the variable parameter transfer function model of the experimental platform is built.The simulation and experimental results show that the tracking error compensation scheme proposed in this paper has stronger robustness and higher control accuracy when the inertia changes than general iterative pre-compensation scheme.Meanwhile,when the inertia is constant,the scheme can still effectively compensate the tracking error.