FINITE-TIME H ∞ STATE ESTIMATION FOR DISCRETE-TIME SWITCHED CONTROL SYSTEMS UNDER ASYNCHRONOUS SWITCHING

The Luenberger observer technique has long been used for reliable state estimation of feedback control systems. In this paper it is employed for asynchronously switched control systems. The theory of finite-time stability (FTS) and finite-time boundedness (FTB) is incorporated, which is a relatively new concept offering open and challenging problems, especially in the field of robust state estimation for switched control systems. Many real-world systems are supposed to run for a fixed interval of time and hence the design of finite-time state observers has more significance from the point of view of many engineering applications. This investigation considers asynchronous switching between observer and physical systems, which accounts for inherent delays in practical applications caused by measurement and sensing mechanisms, and crafts a more practical and accurate design method. Furthermore, H∞ performance index which is a vital technique for robust system design against external disturbances is integrated in the design procedure.