Antilock brake system and method incorporating a pressure feedback
US5171069A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1990 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Apr 23, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S303/04
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An air brake system for a truck includes a treadle valve, a pilot control isolation valve, an exhaust valve, a relay valve, an air pressure transducer, a wheel speed sensor, an electronic control unit (ECU) and an air brake chamber associated with a brake actuator. In heavy braking operations, the pilot system pressure rise rate is monitored and restricted by modulation of the pilot control isolation valve. During heavy braking operations, if braking of the vehicle wheel results in a wheel velocity change which exceeds a predetermined deceleration threshold, the pressure rise rate is further restricted in attempt to "creep" up on the brake system pressure at which the lock condition is expected to occur. At another predetermined deceleration threshold, the brake system pressure is vented. The brake system pressure decreases resulting in a reduction in the applied brake force thereby permitting the vehicle wheel to roll back up to speed. The roll up rate is a function of the friction force. The friction force is used to control parameters of operation of the antilock brake system during subsequent antilock cycles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.