Aircraft anti-skid system modeling and simulation during landing runway path using Simcenter Amesim® and Bond Graphs for failure condition performance evaluation

Resumo

Anti-skid is an electro-hydraulic control, applied in a brake system, that works to prevent aircraft
wheels to lock and slip, mainly with runways under wet or icy conditions. Velocity sensors at the wheels measure
its braking rates. If the speed decreases too rapidly, this could indicate wheel lock-up. In these situations, anti-skid
control acts to relieve pressure at the brakes, so the wheels could be unlocked to prevent slipping.
A business aircraft was selected as a case study, in which the main landing gear system consists of 4 wheels (2
on each side). Brakes are operated by a hydraulic system, which is composed of two segregated hydraulic pressure
sources, actuating on the internal and external wheels, respectively. This configuration prevents inadvertent yaw
movements in the case of failure in one of the hydraulic sources.

The goal of the present work is to model an anti-skid system using bond graph methods and making sub-
sequent computational modeling in Simcenter Amesim®. The model takes into account several effects such as

the contact between tires and runaway; the contact between braking discs; braking disc thermal inertia; hydraulic
actuator dynamics; hydraulic servo-valve dynamics and electric system PID control.