Abstract: The causes of anti-locked braking system (ABS) air-liquid two-phase flow were analyzed to develop
an ABS control algorithm under the effects of gas-liquid two-phase flow. A four-wheel ABS hydraulic model
was established to simulate how various brake fluid parameters and braking line structures affect the brake
pressure using the AMESim software. The results show that gas-liquid two-phase flow occurs when brake fluid
parameters change, with the dynamic response of brake pressure slowing down and the regulating range of
brake pressure reduced. However, reducing the braking line inner diameter can restrain the influence of gasliquid
two-phase flow. The results can provide advice on the ABS control.

Key words: automotive safety, anti-locked braking system (ABS) control, gas-liquid two-phase flow, brake
fluid;, brake pressure, AMESim software