On Finite-Time Extended State Observer And Its Application

With the rapid development of technology,satellite communication on motion(SCOM)plays an important role in modern military,for example,target searching,fighter warning and so on.SCOM servo system determines tracking precision and searching capability of radar and affects overall performance of the radar antenna directly.In this thesis,considering the capability of disturbance rejection and accuracy of SCOM servo system,active disturbance rejection controller(ADRC)based on finite-time extended state observer(FT-ESO)is designed.This thesis studies the third-order finite-time extended state observer,in terms of finite-time observer.It is shown that such an observer has not only the property of estimating the disturbance for ESO,but also has the finite-time convergence of finite-time observer.The definition of finite-time control is introduced,we then prove finite time stability of FT-ESO,i.e,observer design to ensure homogeneity of observation system error,matrix Lyapunov function to prove the asymptotic stability of the observer error system.As a result,it has the finite time convergence characteristics.The superiority and effectiveness of the proposed method are illustrated by simulations.With DSP control as core and Elmo motor as drive,this thesis realizes the closedloop design based on FT-ESO ADRC controller.First,the structure of SCOM servo system is introduced,current speed double closed-loop servo system is analyzed based on the mathematical modeling of the servo system.The designed controller is then successfully applied to servo platform.Finally,FT-ESO based ADRC algorithm is successfully applied to the platform of SCOM servo system.The simulation and experiment in SCOM servo system are carried out,by comparing the simulation results as well as the performance analysis.The control algorithm proposed in this thesis shows the effectiveness and superiority of disturbance rejection and tracking performance.