Research On Active Disturbance Rejection Control With Finite Time Convergence Property Of COTM Antenna Servo System

Communication in the move(COTM)radar is the significant part of the satellite communication.The tracking accuracy and the searching capabilities of COTM radar are directly decided by the antenna servo system.In this thesis,a new control algorithm is proposed based on the COTM antenna servo system.Moreover,the experiment platform of the antenna servo system is established for the feasibility verification.A new active disturbance rejection control(ADRC)algorithm is proposed,which can be converged in finite-time.The proposed control algorithm combines the strong anti-disturbance ability of the ADRC and the fast convergence of the finite-time control.Firstly,a new finite-time extended state observer(FTESO)is designed according to the characteristics of the traditional extended state observer(ESO)and the finite-time observer.This observer has the ability of observing and estimating the disturbance.Meanwhile,it meets the requirement of the finite-time convergence.The corresponding theoretical proof is presented.Secondly,with theoretical basis provided,a convenient method of parameter tuning for FTESO is proposed,which fills the blank of parameter tuning for nonlinear ESO.Thirdly,based on the FTESO,the finite-time active disturbance rejection controller is designed which has better rapidity and stability and can converge to zero in finite-time.The proof and mathematical analysis are given by applications of mathematical induction and Lyapunov method.The on board COTM antenna servo system experiment platform is established with the caliber of 0.9 m by cooperating with the 54 th Research Institute of China Electronics Technology Group Corporation(CETC).The platform can achieve real-time operating condition monitoring and the on-line adjustment of the algorithm parameters,by combining the floating point DSP controller TMS320F28335,the Elmo Driver and the software programming with the upper computer.Finally,the proposed algorithm is verified on the antenna servo system experiment platform.The result indicates that the proposed algorithm is able to achieve rapid and accurate tracking.Its comprehensive performance is better than traditional ADRC,which extremely improves the tracking accuracy of the COTM antenna servo system.