An Uncertainty Model for Saturated Actuators

An uncertainty model for saturated actuators is reported in this paper. The model includes linear as well as quasi-linear elements where the quasi-linear elements are used to model the effects of rate and deflection limiting within the actuator. Since the actuator uncertainty model is quasi-linear, the magnitudes of the signals within the actuator model must be known. Linear and nonlinear simulations are considered for determining the actuator signal magnitudes. An actuator uncertainty model is then obtained for a forward-swept-wing fighter aircraft model. The example demonstrates how actuator saturation uncertainty can affect stability and performance robustness of a flight control system.