Speed change control method and apparatus for an automatic transmission for vehicles traveling under various road conditions
US5390116A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 13, 1992 |
| Grant date | Feb 14, 1995 |
| Priority date | — |
| Expiry date | Mar 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/903
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
In a speed change control method for an automatic transmission for vehicles with a plurality of gearshift positions, the frictional resistance of a road surface is detected, gearshifting to at least a lowest-speed gearshift position is prohibited if the frictional resistance of the road surface is judged to be low. Preferably, gearshifting to at least the lowest-speed gearshift position is prohibited when starting the vehicle from a stopped position if the frictional resistance of the road surface is judged to be low. The frictional resistance of the road surface is determined to be low when an occurrence frequency (%) of the detected frictional resistance value, being less than or equal to a first predetermined value, is more than or equal to a second predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.