Dae-Woo Kim

Fundamental limitations imposed by RHP poles and zeros in SISO systems

Establishes limitations on the impulse response of an LTI system based on the open-loop poles and zeros located in the convergence region of the closed-loop transfer function. Using the definition of Laplace transform, it is shown that time-domain integral constraints have to be satisfied by the impulse response of the SISO stable system and that the maximum value of impulse response has some lower bounds according to the achievable settling time of the system. Also, it shows the reason why it is very difficult to control the system with open-loop RHP (right half plane) poles or zeros using the unity-feedback scheme in the view of small impulse response. These results can be used to determine a priori whether desired design specifications axe achievable or not.

Robust Fault Detection Method for Uncertain Multivariable Systems

Abstract This paper deals with the fault detection problem in uncertain linear multivariable systems having both model mismatch and noise. A robust fault detection method presented by Kwon et al . (1994) for SISO (Single Input/Single Output) systems which accounts for the effects of the variance and bias errors caused by the noise and the model mismatch, has been here extended to the multivariable systems. First, the parameter estimation problem in multivariable system is formulated in a univariable form. Second, the corresponding results to MIMO (Multi Input/Multi Output) systems based on Kwon et al . (1994) are derived. The method proposed is shown to have good performance via a number of simulated systems

Robust H/sub /spl infin// FIR filtering for uncertain time-varying nonlinear systems

Investigates the robust nonlinear H/sub /spl infin// filter with FIR (finite impulse response) structure for nonlinear discrete time-varying uncertain systems represented by the state-space model having parameter uncertainty. Firstly, the discrete-time nonlinear H/sub /spl infin// FIR filter without parameter uncertainty is derived by using the equivalence relationship between the FIR filter and the recursive filter, which corresponds to the standard nonlinear H/sub /spl infin// filter. Secondly, the robust H/sub /spl infin// FIR filter is proposed for discrete-time nonlinear uncertain systems. It is also derived from the equivalence relationship between the robust nonlinear H/sub /spl infin// FIR filter and the robust nonlinear H/sub /spl infin// filter proposed by de Souza et al. (1993).

Maneuvering target tracking in uncertain parameter systems using robust H/sub /spl infin// FIR filters

This paper deals with the maneuver detection and target tracking problem in uncertain parameter systems using a robust H/sub /spl infin// filter to improve the unacceptable tracking performance due to the parameter uncertainty. The tracking filter used is based on the robust H/sub /spl infin// FIR filter proposed by Kwon et al. (1996) to estimate the state signal in uncertain systems with parameter uncertainty, and the basic scheme of the proposed method is the input estimation approach.