An Output Feedback Controller in the Presence of Measurement Error

In the presence of measurement error, a conventional approach to feedback control is to exploit state feedback control and observer simultaneously. However, a large gain in observer often has a tradeoff between tracking error and estimation error. Thus, static output feedback controllers to control a system directly without the observer are proposed. To this end, linear matrix inequality (LMI) was introduced to include a signal to noise ratio (SNR) type constraint efficiently in the development of the controller. Three different static output feedback controllers from using matrix inequality and some approximation are developed. Numerical simulation shows that the method with the smallest matrix dimension provides the best performance in terms of finding the stabilizing the stabilizing controller, which implies that the proposed design may be sensitive to numerical errors.