Disturbance attenuation problem for overactuated systems with actuator saturation: A control allocation based approach

In this paper, a two-stage control allocation based covariance controller design method is proposed to ensure a certain level of disturbance attenuation property for a class of overactuated systems. The proposed method is equally efficient as existing single-stage design technique for assigning a state or output covariance matrix. A set of sufficient conditions has been derived for which the actuator displacements in single-stage technique and in the proposed allocation based method become same. The design steps are formulated in the linear matrix inequality framework. In the presence of actuator saturation, the allocation based method yields better closed-loop performance compared to the single-stage design technique until the level of actuator saturation remains under the attainable range of the allocator. To elucidate the effectiveness of the proposed method, two flight control design examples have been presented.