Fault estimation for uncertain interconnected systems with faults: A lower triangular matrix transformation approach

This paper mainly studies the fault estimation for a class of interconnected systems with simultaneous dynamic uncertainties and actuator faults. A lower triangular matrix based linear transformation theorem is proposed. Based on the theorem, an estimation observer is designed for the interconnected system in consideration. The designed observer with relaxed conditions covers some existing robust observers and adaptive observers in the literature in certain conditions. The fault can be well estimated via the designed estimation observer. Simulation results of a numerical example is presented to show the effectiveness and advantages of the proposed methods.