Active Disturbance Rejection Control for Uncertain Nonlinear Systems Subject to Magnitude and Rate Saturation: Application to Aeroengine
针对受幅值和速率饱和影响的不确定非线性系统，提出一种改进的自抗扰控制器，通过扩展状态观测器和抗饱和回路实现精确估计与扰动抑制，并在航空发动机上验证了有效性。
In this article, the robust control problem of uncertain nonlinear systems subject to magnitude and rate saturation (MRS) is investigated via active disturbance rejection control. To this purpose, we propose a novel robust controller that involves an improved extended state observer (IESO), a composite loop, and two anti-windup loops. The IESO is designed to estimate the state and the total disturbance, which includes the uncertain dynamics and external disturbance. Compared with the traditional ESO, IESO absorbs an anti-windup loop to ensure accurate estimation under MRS. The convergence analysis of IESO is further carried out to theoretically verify the accurate estimation of IESO. The composite loop is generalized to cancel the total disturbance based on the output of IESO. Moreover, a rate anti-windup loop is designed to attenuate the effect of rate saturation on the estimation/cancellation of total disturbance. An algorithm for anti-windup gains computation is correspondingly established, in order to minimize the effect of external disturbance in terms of <inline-formula> <tex-math notation="LaTeX">$L_{2}$ </tex-math></inline-formula> gain while guaranteeing the local asymptotic stability. Finally, the proposed method is applied to aeroengine, which involves large uncertainty and suffers from disturbance and MRS. The experimental results verify the effectiveness of the proposed method.