Design And Application Of Controller Based On Fractional Auto-disturbance Rejection Theory

In recent years,with the rapid development of fractional order theory,the research results of fractional calculus theory have been relatively rich,which has laid a solid foundation for its application in industrial production process control,especially in aerospace,biomedicine,Industrial chemistry and robot process control have been widely used.The theory of fractional calculus is a further extension of the traditional integral order.Now many scholars have studied the fractional order theory deeply and applied the fractional order theory to other controller design.The ADRC technology does not rely on the precise model of the controlled system.The algorithm is simple and robust.It can estimate and compensate the disturbance in the controlled system in real time.In view of its unique structure,each control module does not interfere with each other.But the whole is related to each other,which makes it possible to combine the ADRC algorithm with other control algorithms.By combining the two control algorithms,the control accuracy of the controlled object is greatly improved.The main contents of this paper are:1.The basic theory and related knowledge of fractional calculus are studied.The parameter tuning rules of fractional order controller and the relation between step response characteristic and parameter change are analyzed,and then different controller models are established.The frequency characteristics of three typical links in fractional order control system are analyzed by using MATLAB simulation software,and the influence of controller parameters on the dynamic characteristics of the system is studied.Finally,the design,numerical realization and system simulation analysis of FOPID controller are completed by using amplitude margin method,phase margin method and Z-domain numerical method.2.The structural characteristics and related knowledge of ADRC are studied,and the realization method of ADRC is determined.In this paper,two kinds of control ideas are integrated into the fractional controller,such as arranging the excessive process in the ADRC controller,extending the state observer theory and estimating the disturbance of the compensation system.This paper gives full play to the advantages of fractional calculus controller and active disturbance rejection controller,and puts forward the fractional order active disturbance rejection compound control method.Then,the design scheme and implementation process of fractional order active disturbance rejection controller are studied emphatically.3.Taking permanent magnet synchronous motor(PMSM)as the application object,the FOPID controller,IOPID controller,ADRC controller and FOADRC controller are designed,and the dynamic response and immunity are compared and analyzed.The results show that the active disturbance rejection control and fractional PID control complement each other.Through the experimental simulation,the FOADRC hybrid control scheme proposed in this paper can actively suppress unforeseen interference.The performance of the new FOADRC controller is more accurate than that of the other three controllers,which proves that the method of combining the controller to improve the control performance of the system is reasonable and effective.