自适应广义滑模观测器之状态估计和故障重构

摘要

An adaptive descriptor sliding mode observer (SMO) is proposed to estimate system states and reconstruct actuator fault for a class of uncertain system with both actuator fault and output disturbance. The system model is firstly transformed and augmented to be a descriptor system model. In this way, the actuator fault and output disturbance are decoupled, and the output disturbance turns into new states of the transformed system. Secondly, inspired by the idea of unknown input observer and sliding mode observer, an adaptive descriptor SMO is developed where the strict constraint in the dimension of outputs is relaxed. Meanwhile, with the help of adaptive technique, the requirements of known boundary in disturbance and fault are liberalized. At last, actuator fault is reconstructed based on the idea of equivalent output error injection. Case studies of a reusable launch vehicle during re-entry flights are conducted to demonstrate the effectiveness of the proposed approach.%针对一类同时具有执行机构故障和输出扰动的不确定性系统,提出了一种自适应广义滑模观测器,实现系统状态的估计和执行机构故障的重构.首先,进行系统变换及状态增广构成一类奇异系统,使得执行机构故障和输出扰动解耦,且输出扰动成为增广系统的状态之一;随后,受未知输入观测器和滑模观测器的启发,设计了一种广义滑模观测器,放宽了传统方法对输出维数的严格约束,并通过融入自适应技术放宽了对故障和不确定性上界已知的要求;最后,利用等效误差注入的思想实现故障重构.针对可重复使用运载器再入段进行的仿真实例,验证了所提方法的有效性.