Robustness analysis of nonlinear dynamic inversion control laws with application to flight control

This paper presents the development of robustness analysis tests for quasi-LPV models in the presence of time-varying, parametric uncertainty. The tests are applied for the robustness analysis of nonlinear dynamic inversion control laws giving sufficient conditions for assessing the nonlinear system´s performance in the presence of bounded disturbances and uncertainty. The tests are formulated as linear minimisation problems subject to linear matrix inequality constraints and solved using a gridding procedure. An example is presented in which two nonlinear dynamic inversion control laws for the short-period dynamics of an aircraft are analysed.