Pneumatic panic brake assist
When a brake system on a commercial vehicle, lateral acceleration and/or yaw of the vehicle are monitored and compared to a first predetermined threshold. If the first predetermined threshold is exceeded, a precharge command is sent to the brake system to precharge one or more air chambers by temporarily deactivating a modulator valve and activating an antilock traction relay valve in order to charge the air chambers up to a level permitted by the modulator valve. Upon detecting a panic braking event, a command signal is sent to the brake system to release the precharged air to facilitate braking.
1. A system that facilitates pre-charging an air brake system on a commercial vehicle, comprising:
sensor that detects a stability input value of the vehicle; and
a processor configured to:
compare the stability input value of the vehicle to a first predetermined threshold;
when the stability input value of the vehicle exceeds the first predetermined threshold, send a precharge command to the brake system to charge one or more circuits of the brake system, wherein the precharge command comprises instructions to place one or more antilock brake modulators into a hold state, and an antilock traction relay valve into an energized state in order to precharge the brake system.
2. The system according to claim 1 , further comprising a pedal sensor that detects a pedal event in the commercial vehicle, the pedal event triggering a decrease in vehicle speed.
3. The system according to claim 2 , wherein the processor is further configured to:
compare a magnitude of the pedal event as measured by the pedal sensor to a second predetermined threshold; and
when the rate of travel of the pedal exceeds the second predetermined threshold, send a command to the brake system to transmit the precharged air to the one or more air chambers.
4. The system according to claim 2 wherein the pedal sensor is a travel sensor that detects a rate of travel of the pedal during the pedal event.
5. The system according to claim 2 , wherein the pedal event is an actuation of a brake pedal.
6. The system according to claim 2 , wherein the pedal event is a deactivation of an accelerator pedal.
7. The system according to claim 1 , wherein when the first predetermined threshold is lower than an autonomous braking intervention threshold above which automatic braking is triggered.
8. The system according to claim 7 , wherein the first predetermined threshold is in the range of 50% to 80% of the autonomous braking intervention threshold above which automatic braking is triggered.
9. The system according to claim 7 , wherein the sensor is one of an accelerometer, a yaw rate sensor, and a forward vehicle sensor, and wherein the autonomous braking intervention threshold respectively is one of a lateral acceleration threshold, a yaw threshold, and a following distance threshold.
10. The system according to claim 7 , wherein the autonomous braking intervention threshold above which automatic braking is triggered is a lateral acceleration threshold of approximately 0.3 G.
11. A processor that facilitates pre-charging an air brake system on a commercial vehicle, the processor being configured to:
compare a stability input value of the vehicle to a first predetermined threshold;
when the stability input value of the vehicle exceeds the first predetermined threshold, send a precharge command to the brake system to charge one or more circuits of the brake system, wherein the precharge command comprises instructions to place one or more antilock brake modulators into a hold state, and an antilock traction relay valve into an energized state in order to precharge the brake system.
12. The processor according to claim 11 , wherein the first predetermined threshold is in the range of 50% to 80% of an autonomous braking intervention threshold above which automatic braking is triggered.
13. The system according to claim 12 , wherein the autonomous braking intervention threshold is one of a lateral acceleration threshold, a yaw threshold, and a following distance threshold.
14. The processor according to claim 13 , wherein the autonomous braking intervention threshold above which automatic braking is triggered is a lateral acceleration threshold of approximately 0.3 G.
15. The processor according to claim 11 , wherein the processor is further configured to:
compare a magnitude of a pedal event as measured by a pedal sensor to a predetermined brake pedal rate threshold; and
when a rate of travel of the pedal exceeds the predetermined brake pedal rate threshold, send a command to release the precharged air.
16. The processor according to claim 15 , wherein the pedal sensor is a travel sensor that detects a rate of travel of the pedal during the pedal event.
17. The processor according to claim 15 , wherein the pedal event is one of an actuation of a brake pedal and a deactivation of an accelerator pedal.
18. A method of precharging an air brake system on a commercial vehicle, the method comprising:
comparing a stability input value of the vehicle to a first predetermined threshold; and
when the stability input value of the vehicle exceeds the first predetermined threshold, sending a precharge command to the brake system to charge one or more air modulators of the brake system, wherein the precharge command comprises instructions to place one or more antilock brake modulators into a hold state, and an antilock traction relay valve into an energized state in order to precharge the brake system.
19. The method according to claim 18 , wherein the first predetermined threshold is in the range of 50% to 80% of an autonomous braking threshold above which automatic braking is triggered.
20. The system according to claim 19 , wherein the autonomous braking intervention threshold is one of a lateral acceleration threshold, a yaw threshold, and a following distance threshold.
21. The method according to claim 19 , wherein the autonomous braking intervention threshold is a lateral acceleration threshold of approximately 0.3 G.
22. The method according to claim 18 , further comprising:
comparing a magnitude of a pedal event as measured by a pedal sensor to a predetermined brake pedal rate threshold; and
when a rate of travel of the pedal exceeds the predetermined brake pedal rate threshold, sending a command to the brake system to apply the brakes.
23. The method according to claim 22 , wherein the pedal sensor is a travel sensor that detects a rate of travel of the pedal during the pedal event.
24. The method according to claim 22 , wherein the pedal event is one of an actuation of a brake pedal and a deactivation of an accelerator pedal.
25. An apparatus that facilitates pre-charging an air brake system on a commercial vehicle, comprising:
means for detecting a stability input value of the vehicle;
means for comparing the stability input value of the vehicle to a first predetermined threshold; and
means for sending a precharge command to the brake system to charge the brake system when the stability input value of the vehicle exceeds the first predetermined threshold, wherein the precharge command comprises instructions to place one or more antilock brake modulators into a hold state, and an antilock traction relay valve into an energized state in order to precharge the brake system.
26. The apparatus according to claim 25 , further comprising:
means for detecting a pedal event in the commercial vehicle, the pedal event triggering a decrease in vehicle speed;
means for comparing a magnitude of the pedal event as measured by the means for detecting the pedal event to a predetermined brake pedal rate threshold; and
means for sending a command to the brake system to release the precharged air when the rate of travel of the pedal exceeds the second predetermined threshold.