Aplication Of Model Identification Technology In Lectromechanical Servo System

With the development of industrial technology,the performance requirements of servo electromechanical system continue to improve,and model identification has become an integral part of the design of servo electromechanical system.In the application of model identification technology to servo electromechanical system,there are many problems to be solved,such as the treatment of nonlinear characteristics of the object,the identification scheme of linear model of the object,and so on.These problems restrict the application of model identification technology in the servo electromechanical system,and are also urgent problems to be solved in the practical engineering application.Therefore,this paper will start from these aspects,according to the characteristics of servo electromechanical system,carry out in-depth research on these problems and put forward feasible solutions.In view of the nonlinear problem of the controlled object of the electromechanical servo system,this paper will focus on the mechanism model of two nonlinear characteristics,i.e.the positioning torque and the friction torque,which have great influence on the system.Then,according to the mechanism model and Hammerstein model,the object is established as a block connection structure of nonlinear and linear parts.Then,an identification scheme and a model-based feed-forward compensation scheme are proposed for the nonlinear part of the system,so that the object can be approximated to the linear part after compensation,which greatly reduces the adverse effect of nonlinear factors on the identification and control of the servo system.Finally,the identification and compensation scheme is applied to the small inertia AC servo system to verify the effectiveness of the scheme.In the third chapter,the model identification scheme of the object which can be approximated as a linear link is studied.Firstly,according to the mechanical characteristics of the controlled object of the electromechanical servo system,the existence of resonance mode and its influence on the servo system are analyzed,and the key points of linear object identification are thus determined.Then,the identification method of frequency response model of electromechanical servo system is studied.The application points and identification errors of common frequency response model identification methods are analyzed,and the identification scheme of frequency response model is proposed with partial coherence function as evaluation index.Then,the application difficulty of the parameter model identification method in the electromechanical servo system is analyzed,and the parameter model identification scheme based on the frequency response model is proposed.What’s more,the design method of identifying the input signal is studied,and the signal selection and design scheme are made according to the power spectrum analysis.The parameter model identification scheme and nonparametric model identification scheme proposed in this paper can greatly reduce the blindness of identification,high operability,and relatively intuitive representation of the reliability of the results in different frequency bands in practical application,and can achieve good results in electromechanical servo system.Finally,the linear model identification scheme is applied in the large inertia AC servo platform and the antenna servo platform respectively.By analyzing the system characteristics,reasonably designing signals and selecting identification methods,the frequency response model and parameter model of the object are obtained,and the validity of the model is verified by experiments and data.