By-wire fallback braking mode for brake-by-wire systems in vehicles

摘要

A vehicle includes a brake-by-wire system that delivers a certain amount of brake fluid pressure to wheel brakes depending upon the position of a brake pedal. A brake-by-wire fallback or backup mode of operation is also provided. When activated, this by-wire fallback mode commands a certain, known magnitude of brake pressure. The commanded amount of brake pressure can vary based on the state of a brake pedal on/off switch, and can be set regardless of brake pedal position. This provides a backup to the brake-by-wire system without necessarily requiring a mechanical push-through backup system to brake the vehicle in the event a backup mode is required.

主权项

1. A vehicle comprising:
a brake-by-wire system configured to transmit a brake force to wheel brakes based on signals from a brake pedal position sensor; a mechanical push-through system configured to transmit hydraulic pressure from a master cylinder; and at least one controller programmed to, in response to signal loss from the brake pedal position sensor during brake-by-wire system operation, maintaining brake-by-wire system operations while commanding a predetermined magnitude of the brake force and inhibiting activation of the mechanical push-through system; wherein the at least one controller is further programmed to activate the mechanical push-through system in response to a temperature of the wheel brakes exceeding a threshold.