On-grade shift logic with provision for skip downshifts
US4916979A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 18, 1988 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Apr 18, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2061/0444
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved control system and method for an automatic/semi-automatic transmission system (10) including an automatic change gear transmission (12) driven by a throttle (26) controlled engine (14) is provided. The control system includes a processing unit (42) for receiving inputs indicating at least throttle position (THL) and vehicle speed (OS) and for determining vehicle deceleration (dOS/dt) and for processing these inputs in accordance with a program or logic rules to determine the selected engaged gear ratio and for issuing command signals to a transmission shifting mechanism (34). The processing unit includes logic rules by which vehicle performance is maximized and the control will evaluate and allow and/or execute skip downshifts upon sensing conditions indicative of vehicle deceleration due to ascending a steep grade.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.