Computer Simulation and Parameter Sensitivity Study of a Commercial Vehicle During Antiskid Braking

Abstract

A large-scale digital computer model, used for simulating the dynamical response of commercial vehicles, was employed in a parameter sensitivity study which focused on the antiskid braking performance of a heavy truck. Full-scale vehicle test results and laboratory measurements were used in developing a baseline computer representation of the test vehicle. Subsequent to the development of the baseline computer representation, the computer simulation was exercised to study the influence of various vehicle and antiskid system parameters. Basic categories examined in the parameter sensitivity study were: brake system properties, vehicle mass and inertia properties, tire traction characteristics, suspension properties, wheel dynamics, and antiskid system characteristics.

The antiskid braking performance of the examined baseline vehicle was primarily dominated by the adverse effects deriving from rear brake torque imbalances and hysteresis precipitated during wheel cycling.

The most noteworthy findings of the parameter sensitivity study for improving the baseline stopping performance, outside of reducing the side-to-side imbalances and rear brake hysteresis, were found to be: (a) reduction in rear brake effectiveness or use of load proportioning valves, (b) modification of antiskid system operation, and (c) modification of rear suspension properties.