Speed change control method for setting a gearshift position of an automatic transmission for vehicles based upon driver acceleration intention and external variables
US5428531A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 13, 1992 |
| Grant date | Jun 27, 1995 |
| Priority date | — |
| Expiry date | Mar 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S477/904
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
When a vehicle is traveling on a descending slope, the gearshift position of an automatic transmission is set to a position selected in accordance with driver's intention to accelerate the vehicle based on the accelerator opening. A decision is preferably made as to whether the gearshift position should be set to a low-speed gearshift position where an engine brake can be applied, in accordance with the magnitude comparison between a threshold value and at least one value of a gradient of a road and a timedependent change in vehicle speed. The threshold value may be changed to a value that causes the low-speed gearshift position to be easily selected if the frictional resistance of the road surface is judged to be low. Further, the threshold value may be preset corresponding to the degree of gradient and/or winding of the road. Further, the threshold value is changed to a value that causes the low-speed gearshift position to be easily selected if the detected operating amount of braking exceeds a predetermined standard value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.