基于辅助输出构造的未知输入观测器设计

研究了观测器匹配条件不满足之前提下,状态和未知输入同时估计的未知输入观测器的设计方法.基于可测输出相对于未知输入的相关度的概念,给出了可以满足匹配条件的辅助输出的构造方法.考虑了一种高阶滑模观测器,根据原系统的可测输出不仅能给出辅助输出、还能给出其微分在有限时间内的精确估计.基于辅助输出,提出一种能对状态渐近估计的降维观测器设计方法.基于状态和辅助输出之微分的估计,提出了一种未知输入的重构方法,该方法具有不必用到系统微分信息的优点.最后通过一仿真实验验证方法的可行性.

Unknown input observer design based on auxiliary outputs

A design method of unknown input observer which is able to estimate simultaneously the system states and the unknown inputs was proposed when the observer matching condition is not satisfied. Based on the concept of relative degree with respect to unknown input, the auxiliary outputs were designed so that the newly-constructed output equation can meet the matching condition. A high-order sliding mode observer was considered to get the exact estimates of both the auxiliary outputs and their derivatives in a finite time based on the system measured outputs. Then a reduced-order observer which can asymptotically track the real states of the system was constructed. A kind of unknown input reconstruction method based on both the state and the auxiliary output derivative estimates was developed. None of system differential information has been used directly when the unknown inputs was reconstructed. The simulation results to a system show that the proposed method is effective.