Accessibility, Observability, and Fault-Tolerant Control Structure Selection of Network Nonlinear Systems

An appropriate control structure is the prerequisite to guarantee the controllability and the observability of a system. This article addresses the issue of fault-tolerant control structure selection (CSS) problem for a class of network nonlinear systems (NNSs) with multidimensional nodes. First, based on differential algebra theory, necessary and sufficient accessibility/observability conditions are established, respectively, for NNSs, which fully reveal the relations between the accessibility/observability and the network structure as well as external inputs/outputs. Second, a fault-tolerant CSS-based recovering strategy is provided that adds minimal inputs/outputs/edges to recover the accessibility and observability of the faulty NNS. Finally, the new strategy is applied to examples of chemical reaction and multiple aircrafts to illustrate the effectiveness of the theoretical results.