Disturbance and Time Constant Estimation for Compensating Dynamics of Guidance Systems in Intercept Problems

Abstract

In this paper, we propose two estimators to compensate the target's maneuver and uncertain vehicle dynamics including uncertain system lag; one is an extended state high-gain-observer-based estimator to estimate an uncertainty and disturbance term (UDT) which affects the line-of-sight (LOS) rate dynamics, and the other is a novel filter to estimate the uncertain system lag. Generally, a linearized system from its original system for the estimation of the uncertain system lag is unobservable, whereas, we can make the system observable with the filter. The effectiveness of those compensation methods are shown by conducting some representative numerical simulations and comparing with a conventional compensating method. The filter which estimates the uncertain system lag used in combination with the high-gain-observer-based estimator has made better performance than the one used in combination with the conventional method in terms of convergence time and resulting miss distance.