A deceleration-based algorithm for anti-skid control of aircraft

Anti-skid control systems are standard equipment for aircraft of all sizes. Such systems are designed by rather few braking systems suppliers, with control algorithms that have never been presented, nor analysed, in the scientific literature. From industrial practice, it is known that such controllers act on a single landing gear, that they use a single wheel speed measure, and that they require extensive trial-and-error tuning before release. In this paper, we first analyse experimental data measured on closed-loop braking tests to see which is the behaviour of the controlled aircraft when braking. Then, we propose a control-oriented modelling of the landing gear, that allow disclosing its dynamic features. Based on this, we present an anti-skid control algorithm that achieves a very similar closed-loop behaviour to that experimentally experienced. The performance of the controller are quantitatively analysed according to cost functions that are standards in the aeronautic braking systems evaluation.