SOLENOID QUICK EXHAUST CIRCUIT FOR IMPROVED ANTI-LOCK PERFORMANCE IN AN ELECTRONIC BRAKING SYSTEM

摘要

A system and method are provided for controlling an anti-lock braking system (ABS) in a motor vehicle where the ABS is performed by an electronic braking system (EBS) which includes a pulse width modulating (PWM) drive circuit connected to a solenoid (30) in a modulator valve (20). The modulator valve controls air from a pressurized air source (12) to a brake cylinder. The PWM drive circuit (100) allows the solenoid to accurately control the pressure t o the brake cylinder during the braking operation to control the smoothness of the current and force profiles. During steady-state control operation of the system, a diode (146) in the drive circuit is connected in parallel with the solenoid. When quick dissipation occurs, the diode is eliminated from the circuit by opening the drive circuit with a high-side and low-side switch system (44, 120). This allows for optimal performance of the drive circuit when the EBS is in either the steady-state or quick dissipation mode.