Vacuum actuated vehicle speed control system
US6424905B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1999 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Sep 22, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60W2520/105
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A method and system adjusts powertrain controls to avoid significant deviations from set speed during speed control operation. Low vacuum conditions of a reservoir vacuum resulting from high load conditions are detected and eliminated through the initiation of downshifts. Detection is based on the determination that speed control mode has been initialized, the throttle is extended, vehicle acceleration is low, and there has been a significant deviation from set speed. The downshift creates an increase in engine rpm and a reduction in throttle angle to increase the manifold vacuum and thereby recharge the reservoir vacuum and eliminate the low vacuum condition. The transmission can be returned to normal operation and the pre-adjustment gear upon elimination of the low vacuum condition or the occurrence of a driver override condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.