On dynamic inversion with rate limitations

This paper investigates new ways of accounting for saturations in nonlinear dynamic inversion schemes. Because of its high practical interest, the particular case of rate limitations will receive a special attention here. The central contribution of the paper consists of showing how the nonlinear control problem can be rewritten in a standard form, strongly inspired by the robustness analysis framework. More precisely, standard dynamic-inversion-based controllers are viewed in this paper as particular solutions to a more general nonlinear compensation scheme. Various strategies are then proposed to solve the problem, among which multi-channel H_∞ design approaches - for which new optimization tools were recently made available - will play a key role. In a second step, anti-windup optimization is also considered to further improve the control laws. The proposed methodology is illustrated by a realistic aircraft control design example.