Tire-Wear Control in Aircraft via Active Braking

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 model 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, using an appropriate anti-skid control approach, one may directly formulate the braking problem as a tire consumption regulation one, being sure that the resulting braking performance will have an a priori guaranteed outcome. The tire wear model is also validated in an experimental setting.

Analysis of landing gear walk vibration characteristics excited by aircraft anti-skid brakes

“…In [6], the landing gear strut was simplified to a torsional spring-damping system in the longitudinal direction, and a detailed gear walk vibration mechanical model was established by using Lagrange's second-type equation. To characterize the effect of landing gear walk on aircraft ABS, a simplified landing gear coupling vibration analysis model based on landing gear walk angle is established in [7][8]. The above study directly simplified the landing gear walking vibration to a low-order vibration system, and the boundary conditions of the simplified model were not analyzed.…”