Multiobjective design of robust fault detection systems

Abstract

This chapter considers the multiobjective integrated design of fault detection systems for linear time-invariant systems with unknown inputs. The unknown inputs are classified into two parts: the part of unknown inputs that should be decoupled and the part of unknown inputs that needs not to be decoupled. The sensitivity of the Fault detection (FD) system to the faults is also taken into account in the design. First, the residual generator is designed in such a way that the residual is decoupled from the unknown inputs that mainly influence the system. Then, the rest freedom is used to improve the robustness of the residual generator to other unknown inputs and its sensitivity to faults. By virtue of the close relationship between the parity space approach and the observer based approach, the order of the residual generator can be kept at a low and flexible level. The result reported in this paper is an application of the recently developed properties of the parity space approach.