复合风场影响下RLV着陆段固定时间控制OACSTPCD

A fast and high-precision control method based on the double-power fixed-time stabilization theory is presented to address the problems of the vertical takeoff and landing reusable launch vehicle(RLV)under the influence of multi-type complex wind field disturbance during the return-landing section,e.g.,strong coupling between the convergence time upper bound of attitude tracking control and the initial state and the serious degradation of the tracking performance.First,the natural wind fields subject to the RLV return-landing section is classified and modeled,and the influence of the wind fields on the attitude control of the return-landing section is analyzed.Second,based on the back-stepping framework,a convergence law in the form of high and low power-weighted polynomials is designed to ensure that the system state error converges within a fixed time and the convergence time and the upper bound are independent of the initial state.Meanwhile,in order to reduce the influence of wind field disturbance on the performance of the control system of the RLV return-landing section and ensure the stability of the control performance of the landing section and landing safety,a fixed-time extended state observer is introduced to estimate and compensate for the wind field perturbation.Finally,based on the Lyapunov theory,it is proved that the control law can make the attitude control error of the RLV return-landing section converge within a fixed time.Moreover,the effectiveness of the proposed control scheme is verified by various numerical simulations.