Fault Tolerant Flight Control

Abstract

A fault tolerant flight control system is developed. The three-module controller consists of 1) a system identification module, 2) an adaptive parameter estimate smoother, and 3) a proportional and integral compensator for tracking control. Specifically, the classical Kalman filter for linear control systems is extended so that the control system's state and loop gain are jointly estimated online, and an adaptive smoother is developed to reduce automatically the fluctuations in the gain estimate and bursting. The output of the system identification and gain smoother modules is used to adjust continuously the tracking controller's gain to compensate for a possible reduction in the loop gain due to control surface area loss caused by failure or battle damage.