Adaptive estimation and accommodation of loss of control effectiveness using a Lyapunov method

A Lyapunov approach is used to design regulators for systems subject to loss of control effectiveness. Control effectiveness factors are used to quantify faults entering control systems through actuators. An adaptive Kalman filtering algorithm is used to estimate the state as well as the amount of reduction of control effectiveness in a closed-loop setting. The state estimate is fed back to achieve the steady state regulation, while the control effectiveness estimate is used for the online tuning of the control law. The resulting regulator is guaranteed to be stable when the estimation error is sufficiently small. An aircraft longitudinal model is used to demonstrate the use of the Lyapunov method.