New results on output feedback disturbance attenuation of saturated linear systems

In this paper, we will study the problem of disturbance attenuation by output feedback for linear systems subject to actuator saturation. Both continuous and discrete-time systems are considered. A nonlinear output feedback, expressed in the form of a quasi-linear parameter-varying system, is constructed that minimizes the the effect of the disturbance on the output of the system. The level of disturbance attenuation is measured in terms of the regional ℒ₂ gain and ℓ₂ to ℓ_∞ gain over a class of energy-bounded disturbances.