Fault estimation observer design for a class of nonlinear multiagent systems in finite-frequency domain

This paper focuses on the fault estimation observer design problem in the finite-frequency domain for a class of Lipschitz nonlinear multiagent systems subject to system components or actuator fault. First, the relative output estimation error is defined based on the directed communication topology of multiagent systems, and an observer error system is obtained by connecting adaptive fault estimation observer and the state equation of the original system. Then, sufficient conditions for the existence of the fault estimation observer are obtained by using a generalized Kalman-Yakubovich-Popov lemma and properties of the matrix trace, which guarantee that the observer error system satisfies robustness performance in the finite-frequency domain. Meanwhile, the pole assignment method is used to configure the poles of the observer error system in a certain area. Finally, the simulation results are presented to illustrate the effectiveness of the proposed method.