Eaton Corporation

Warren R Dedow

Jon A Steeby

Daniel P Janecke

Steven Louis Melvin

Mark A Boardman

A shift control system is provided that is suitable for semi-automatic transmissions in heavy duty vehicles. The torque modulation system includes logic circuitry that employs a ramping torque function or algorithm to control the acceleration of torque, both positive and negative, and/or provides a longer dwell time in the torque clutch disengagement range. Moreover, dwell time at peak is not required. A method for improving gear disengagement and shift control in accordance with the principles of the invention is also disclosed.

Torque modulation shift control system and method

A control method/program for rapidly confirming engagement of a target gear ratio (GR.sub.T) in an automated mechanical transmission system (92) on the basis of input signals (ES, or IS, OS) indicative of transmission input shaft (18) and output shaft (58) rotational speeds.

Engagement of gear ratio confirmation

An automated mechanical transmission system (92) including anti-hunt logic (FIG. 7) and logic allowing the operator to reduce or cancel the anti-hunt logic offsets by post-shift throttle pedal (THL) manipulation.

Anti-hunt logic

A control for confirming disengagement of a disengaging gear ratio (GR). Signals indicative of input shaft speed (ES or IS) are compared to signals indicative of output shaft rotational speed (OS) to determine if the quotient of input shaft rotational speed to output shaft rotational speed (IS/OS) remains outside an increasing-sized window (GR.+-.error, GR.+-.2*error, GR.+-.3*error).

Disengagement confirmation

A partially automated mechanical transmission system (92) includes a splitter-type compound transmission (10) and controls for automating splitter shifting upon manual selection of the highest main section ratio position (ninth/tenth). Logic is provided to provide an optimized response to manual shifting into main section neutral from the highest main section ratio position.

Automode-to-neutral logic

A control system and method for controlling start-from-stop operation in an automated mechanical transmission system, including a multiple-speed change-gear transmission (10) having a lowest grouping of ratios (first-fourth) suitable for start-from-stop operation, is provided. Upon a request or requirement for a shift into a default start ratio, the system controller (106) will cause initiation of a shift into the highest gear ratio (fourth) of the lowest group of ratios.

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Portage, MI, United States of America

Warren R Dedow