Finite Time State Estimation and Fault Detection for Linear Switched Systems with Unknown Inputs

In this paper, we consider using finite time switched observer to estimate the states and detect the faults for a type of linear switched system with unknown inputs. We first design the finite time switched observer by a reduced-order switched system which originates from the primary switched system, where the unknown inputs are removed with the help of state and output transformations. A cluster of finite time observers are presented for all of the reduced-order subsystems. Then, by choosing any small time parameters, we can get the finite time state estimation of the reduced-order switched system by finite time switched observers. And the finite time state estimation of the primary switched system is acquired by state equivalent transformations. Next, we put forward a fault detection method using output residual. Finally, a MATLAB simulation result is presented to confirm the reliability of the method we put forward.