Patent Number: 6,253,140

Title: Engagement control logic for an automatic transmission clutch with adaptive engagement feel

Abstract: An adaptive control system and method for direct clutch engagement control for an automatic transmission including a micro-controller that receives and stores input data from driveline sensors and executes transmission clutch control logic. The micro-controller develops output signals in real time and transfers the signals to a driver circuit that controls solenoids that enable clutch engagement. The signals for establishing clutch pressure buildup are delivered to a driver circuit that produces hydraulic pressure at the clutch to achieve a smooth torque and speed transition for the torque input elements of the transmission. Adaptive pressure values are stored in a keep-alive memory. The pressure values are adjusted values based on the result of previous engagements. This compensates for driveline variables such as changes in coefficients of friction, spring loads, clutch wear, etc., whereby engagement cycle time is reduced and actual pressure buildup rate is maintained close to desired value to achieve a desired slip change rate, thereby achieving consistent, improved engagement quality.

Inventors: Jain; Pramod Kumar (Farmington Hills, MI), Kuhn; Howard Cecil (Farmington Hills, MI), Vodicka; Ronald James (W. Bloomfield, MI)

Assignee: Ford Global Technologies, Inc.

International Classification: G06F 7/00 (20060101); G06F 007/00 ()

Expiration Date: 06/26/2018