Combining tire-wear and braking control for aeronautical applications

Abstract

In ground vehicles, tire consumption is in general mainly due to the mileage covered, and in fact the life span of tires, at least in common situations, is rather long. In the aeronautical context, and for aircraft in particular, instead, tire consumption plays a crucial role in determining the maintenance costs. This is due to the fact that, in aircraft braking, nearly all maneuvers activate the anti-skid controller, which remains in use for long time intervals. In ground vehicles, instead ABS systems are usually active for short time intervals which cover a part of the braking maneuvers only. Thus, tire consumption in the automotive context is usually studied under constant speed assumptions. In this work, we formulate a tire consumption models that encompasses explicitly the wheel acceleration/deceleration dynamics, and we show that tire wear can be directly related to the anti-skid controller parameters. Based on this, a sensitivity analysis of tire-consumption versus braking performance is carried out, showing that the braking control problem can be reformulated as a tire consumption regulation one.

Data-Driven Modeling and Regulation of Aircraft Brakes Degradation via Antiskid Controllers

“…In order to analyse how the braking actuator usage status and the tire energy consumption can be directly related to the anti-skid controller parameters, a wheel slip anti-lock braking system was designed and an analysis was performed on how the energy distribution for these two components depends on the wheel slip set-point value λ, selected for the controller tracking performance. The slip controller was selected due to the straightforward tuning procedure and the possibility to extract a direct relationship between its parameters and component wear, already proved in [22], [23]. A simplified schematic representation of the controller is represented in Fig.…”

“…Hence, current ABS approaches are still mostly deceleration-based, and they aim at generating a stable limit cycle on the wheel speeds. Recent works, see e.g., [22], [23] proved that a wheel slip control approach, could provide significant advantages, not only increasing performance and reducing the time needed for design and tuning, but also allowing a direct control of the tire usage. The longitudinal speed estimation problem is particularly challenging in the aeronautic context, because of the aforementioned limitation in the available measurements.…”

“…This, in turn, is caused by the sliding motion between the braking pads and wheel disc surfaces, and for this reason it is proportional to the applied pressure per unit of surface and to the sliding distance [31]. The sliding between the wheel and road surface, as well as the one between the braking pads and wheel disc, are not independent, but instead they are coupled and connected via the applied pressure, which is regulated by the anti-skid controller [22], [23]. The pressure profile commanded by the anti-skid controller for a given aircraft braking maneuver determines the distribution of the energy dissipated between the two components and hence their relative consumption.…”

Tire-Wear Control in Aircraft via Active Braking

“…In this paper, we offer, to the best of our knowledge, the first detailed contribution to tire wear modelling for aircraft, introducing a dynamic description of this phenomenon that allows us to capture the importance of its close relationship with anti-skid braking. This work leverages a first brief description of these results currently submitted to the 2019 ECC, [6]. The conference version of the paper presents a limited part of the material contained in this manuscript.…”

“…In this appendix, the linearized model of the landing gear dynamics given in(6) is presented, based on which the transfer functions from braking torque to wheel slip and wheel deceleration are computed. The state and input vectors are defined as follows x = ω v a θ θ T ; u = T b ; y = ω .where: ω is the wheel speed, v a is the longitudinal aircraft speed, θ ,θ are the gear-walk angular speed and position, T b is the braking torque.…”