On the Stopping Criteria n Nonlinear Unknown Input Observability Condition

• 成果类型: Article
• 署名作者: Sarafrazi, Mohammad Amin; Kotta, Ulle; Bartosiewicz, Zbigniew
• 署名单位: Tallinn University of Technology; Bialystok University of Technology
• 刊物名称: IEEE TRANSACTIONS ON AUTOMATIC CONTROL
• ISSN/ISSBN: 0018-9286
• DOI: 10.1109/TAC.2022.3160133
• 发表日期: 2022
• 页码: 4733-4737
• 关键词: Nonlinear system; observability; unknown input

摘要

Observability of nonlinear systems with unknown inputs was recently characterized in terms of dimension of an observability codistribution, obtained from Lie derivatives of outputs with respect to an infinite set of vector fields. However, the suggested stopping criterion does not apply to all systems, and the applicability condition is difficult to check. This article provides a new stopping criterion which holds universally and is easy to check. Moreover, we show that for systems with n states, in the single-input single-output case the algorithm for computing observability codistribution converges in no more than 3n - 1 steps, while in the multi-input multi-output case addition of each independent input or output channel reduces this upper bound by one.