Gm Global Technolgoy Operations, Inc.

William J Wegeng

Edmond M Etchason

Peter Edwin Swingler

Randall S Conn

Mark A Rushing

Barry Lewis Ladd

Ronald P Hitch

John D Hylton

Ricke D Katko

A method for controlling a transmission in a motor vehicle during acceleration from an idle condition begins when the vehicle is stationary, the engine is at idle, and the transmission is in the first gear range or ratio. When the vehicle begins to accelerate, the method includes the steps of monitoring the rate of vehicle acceleration and comparing the rate of vehicle acceleration to a rate of vehicle acceleration threshold. If the rate of vehicle acceleration is less than the acceleration threshold, then the transmission allows one of the currently engaged clutches to slip. This clutch slip reduces the torque load on the engine. The method then monitors the engine output speed. If the engine output speed exceeds an engine output speed threshold, then the clutch is fully applied.

Method for controlling a transmission during acceleration from idle

An apparatus and method is provided for controlling torque in a powertrain having an engine and a transmission capable of operating a power take-off unit. The apparatus includes: a controller selectively operable to send a power take-off unit activation request to a transmission control module within the powertrain; a transmission control module capable of receiving the power take-off unit activation request; and wherein the apparatus is configured to prevent the torque of the engine from exceeding a maximum defined torque value when the power take-off unit is in operation. The apparatus includes an engine control module capable of receiving commands from the transmission control module through a data link connecting them.

Apparatus and method of engine torque control during power take-off operation in a motor vehicle

A vehicle transmission retarder control apparatus is provided including an engine, a throttle, a brake, a transmission having an output member with an actual transmission output speed, a speed sensor operable for measuring the actual transmission output speed, a plurality of user-commandable input devices for selecting a desired transmission output speed, and a controller having an algorithm for controlling the amount of retarder request to provide a zero or constant rate of deceleration independently of weight and axle ratio. Additionally, a method is provided for controlling a transmission retarder, including measuring the actual transmission output speed, sensing a desired transmission output speed using a plurality of user-commandable input devices, communicating the actual and desired speeds to a controller, and commanding the retarder to apply a continuously variable opposing torque to the transmission based on the actual and desired output speeds to achieve a constant rate of deceleration.

Adaptive retarder control method and apparatus

One or more friction devices of a transmission coupled to an engine through a fluid coupling are used during engine neutral idle operation to control the state of the fluid coupling for synchronous engagement and disengagement of a PTO input gear with a transmission-driven gear. The fluid coupling includes an input member connected to the engine and an output member connected to the input shaft of the transmission, and the transmission friction devices temporarily ground the output member without mechanically coupling the transmission input and output shafts under specified enable conditions. This maintains the transmission input shaft in a stationary condition while an actuator engages or disengages the PTO input gear with the transmission-driven gear. Following engagement or disengagement of the PTO input gear, the friction devices are released to resume normal operation of the fluid coupling.

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Avon, IN, United States of America

William J Wegeng