Patent · US Expired

Gear shift control system of an automatic transmission

US5235875A · kind A · utility

15Cited by
5References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 13, 1992
Grant dateAug 17, 1993
Priority date
Expiry dateFeb 13, 2012

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S706/90
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A gear shift control system according to this invention includes a throttle opening sensor, a vehicle speed sensor and a controller for delivering a shift command signal to an automatic transmission. The controller is previously stored with shift lines, which divide the respective regions of gear-shift stages, on the basis of the throttle opening and the vehicle speed. The controller delivers the shift command signal to the transmission when any of the shift lines is crossed by a shift point which is defined by the throttle opening and the vehicle speed. Taking account of the changing rate of the throttle opening, the past throttle opening, and the acceleration of the vehicle, however, the controller calculates a decision value which is indicative of the running state of the vehicle, on the basis of the fuzzy theory. When the decision value exceeds a predetermined value, the controller corrects the shift lines depending on the running state.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.