Tavasolipour Elham, Poshtan Javad, Shamaghdari Saeed
Department of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran.
Department of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran.
ISA Trans. 2021 Aug;114:31-43. doi: 10.1016/j.isatra.2020.12.040. Epub 2020 Dec 28.
The problem of fault estimation for nonlinear systems with Lipschitz nonlinearities is addressed in this work for the estimation of both the system fault and states. In the proposed approach disturbance is regarded to be a function which is nonlinear and coupled with states of the system, and fault to be a function which is additive. In order to diagnose the fault and reduce the disturbances effects by dissipativity theory, Luenberger and two unknown input observers (UIOs) are designed separately. If the system satisfies the matching condition, the first UIO can accurately estimate faults by decoupling the effects of state-coupled disturbances. Otherwise, the second UIO estimates faults by decoupling partial disturbances, and attenuating the disturbances which cannot be decoupled. The essential conditions for all designed observers to exist are stated. Finally, the suggested method is applied to a robot by simulation to analyse its performance.
本文针对具有Lipschitz非线性的非线性系统的故障估计问题，进行了系统故障和状态的估计。在所提出的方法中，干扰被视为一个非线性且与系统状态耦合的函数，故障被视为一个加性函数。为了利用耗散理论诊断故障并降低干扰影响，分别设计了Luenberger观测器和两个未知输入观测器（UIO）。如果系统满足匹配条件，第一个UIO可以通过解耦状态耦合干扰的影响来准确估计故障。否则，第二个UIO通过解耦部分干扰并衰减无法解耦的干扰来估计故障。阐述了所有设计观测器存在的必要条件。最后，通过仿真将所提方法应用于一个机器人，以分析其性能。
