Research Of Variable Gain High-order Sliding Mode Filter

After decades of improvement and development of control theory,filtering the noise of the feedback signal and estimating the derivative of its signal component in the control system has gradually become an extremely important research topic in the field of control.If the traditional method of numerical difference estimation is directly used to calculate the derivative of the signal polluted by noise,it will undoubtedly amplify the noise in the system,which will have a serious effect on the control accuracy of the system,even directly lead to the system failure.With the gradual deepening of the research,different filters to filter out the noise in the signal has become a widely recognized solution.Among them,the problems of large phase lag and limited noise attenuation performance of linear filter have become the constraints of its further development.In addition,nonlinear filters such as median filter and Kalman filter shave the problems of high computational cost and need to use exact system model.In recent years,sliding mode filter has attracted wide attention in academia because of its advantages of high precision,strong robustness and no need of system models.In this paper,the adaptive gain high-order sliding mode filter is selected as the research topic,and the existing problems and the causes of the problems of the traditional high-order sliding mode filter are analyzed,and the main research work is as follows:Firstly,aiming at the existing problems of traditional high-order sliding mode filter,such as filtering effect,tracking performance and system overshoot,a new adaptive gain high-order filter is proposed based on the existing research results.The advantage and innovation of this algorithm is that it can be used by any order sliding mode filter,and the gain of the system can be adaptively changed according to the frequency and amplitude of the input signal.Using this adaptive method,the new high-order sliding mode filter can improve the filtering performance and tracking performance of the traditional high-order filtering system when processing complex signals.In addition,the new high-order sliding mode filter improves the auxiliary variables of the system and realizes the overshoot suppression for any order filter.This paper also explains the parameter variation and influence of the new high-order sliding mode filter and the stability of the system through simulation comparison and theoretical analysis.Finally,the performance advantages of the new high-order sliding mode filter are verified by simulation examples in both step response and dynamic response.In addition,some scholars have proposed a parameter adaptive estimation algorithm for high-order sliding mode filter under the condition of known input signal expression.This algorithm is also applied to the traditional high-order sliding mode filter to verify the effectiveness of the proposed parameter adaptive estimation algorithm...