Computer controllable synchronous shifting of an automatic transmission
A multiple forward speed automatic transmission produces its lowest forward speed ratio when a hydraulic clutch and hydraulic brake are disengaged and a one-way clutch connects a ring gear to the transmission casing. Second forward speed ratio results when the hydraulic clutch is engaged to connect the ring gear to the planetary carrier of a second gear set. Reverse drive and regenerative operation result when an hydraulic brake fixes the planetary and the direction of power flow is reversed. Various sensors produce signals representing the torque at the output of the transmission or drive wheels, the speed of the power source, and the hydraulic pressure applied to a clutch and brake. A control algorithm produces input data representing a commanded upshift, a commanded downshift, a commanded transmission output torque, and commanded power source speed. A microprocessor processes the inputs and produces a response to them in accordance with the execution of a control algorithm. Output or response signals cause selective engagement and disengagement of the clutch and brake at a rate that satisfies the requirements for a short gear ratio change and smooth torque transfer between the friction elements. 6 figs.
- Research Organization:
- Ford Motor Company, Detroit, MI (United States)
- DOE Contract Number:
- AC07-85NV10418
- Assignee:
- IDO; EDB-94-116114
- Patent Number(s):
- US 4855914; A
- Application Number:
- PPN: US 7-126064
- OSTI ID:
- 7168173
- Resource Relation:
- Patent File Date: 27 Nov 1987
- Country of Publication:
- United States
- Language:
- English
Similar Records
Method for controlling a motor vehicle powertrain
Method for controlling a motor vehicle powertrain