Gm Global Technolgoy Operations, Inc.

Andrew L Mitchell

Jeffrey Kurt Runde

Brett Caldwell

Phillip F Mc Cauley

John P Kresse

Scott E Mundy

Kevin Kluemper

Scott T Kluemper

Steven Franklin James

A system for controlling a transmission of a vehicle powered by an engine includes a torque determination module and a shift determination module. The torque determination module determines a desired exhaust brake torque for the engine based on an actual speed of the vehicle and a desired speed of the vehicle. The shift determination module determines whether to shift between gear ratios of the transmission based on the desired exhaust brake torque and an exhaust brake torque capacity of the engine.

System and method for controlling a transmission to improve exhaust braking

A system for calibrating a transmission includes a slip generation module, a volume determination module, and a calibration control module. The slip generation module generates transmission slip. The volume determination module, after the transmission slip has been generated, applies a torque converter clutch (TCC) and determines a volume of the TCC based on a period for the TCC to fill with hydraulic fluid. The calibration control module generates a calibrated volume based on the determined volume and calibrates a control module based on the calibrated volume, wherein the control module controls the transmission.

System and method for determining a volume of a torque converter clutch and calibrating a transmission

An improved downshift control for an automatic transmission optimized for sequential shifting achieves a non-sequential fifth gear to third gear downshift by reducing the main pressure of the transmission hydraulic control system, allowing a offgoing clutch to slip, disengaging the offgoing clutch, using torque reduction to control engine speed, engaging the oncoming clutch, increasing the main pressure of the transmission hydraulic control system and using torque reduction to synchronize the transmission input speed with the third gear transmission output speed.

Multi-stage non-sequential downshift control for an automatic transmission

A system for braking a vehicle includes a transmission having a plurality of gear sets for establishing a plurality of forward and reverse gear ratios and an actuator for changing the gear ratios. The system also includes a plurality of sensors for detecting a plurality of vehicle operating parameters and an auxiliary brake for reducing a speed of the vehicle. A controller having a processor configured to receive a plurality of output signals from the plurality of sensors has control logic for activating one of the actuator and the auxiliary brake based on the received output signals. A method for operating the system for braking is also provided. The method includes determining road grade, determining an acceleration of the vehicle, determining an activation status of the primary brake, determining a position of the throttle, determining whether extra braking is and activating the auxiliary brake based on the extra braking determination.

Automatic braking system

A method is provided for determining variance of actual engine torque from reported engine torque, including configuring a controller with an algorithm to calculate the ratios of current and maximum engine torque to reported torque upon the initiation of high-throttle 1-2 shift, high-throttle 2-3 shift, high-throttle torque converter lockup, and at maximum Engine Rating Torque Function for each high-throttle torque converter drive cycle. An apparatus is also provided for detecting engine torque variance in a vehicle having an engine, a throttle, and a torque converter, the apparatus comprising a controller with memory and an algorithm for calculating the maximum and current engine torque variance upon the occurrence a predetermined throttle condition, and storing the values in accessible memory, wherein the controller is configured to initiate the algorithm upon the occurrence of one of the throttle conditions, and wherein the throttle and torque converter each communicate speed signals to the controller.

Engine overrate detection method and apparatus

According to a preferred embodiment of the present invention, a clutch is applied when the vehicle comes to a stop. The application of this clutch locks the output shaft with energy stored therein. When the shift selector is then moved to the park position, the clutch releases the stored energy in a controlled manner by slipping the clutch plates. The controlled slipping reduces the noise as the park pawl tooth contracts an output gear tooth.

Method for improving a drive-to-park shift

An improved method of operation for a motor vehicle automatic transmission determines a vehicle speed for purposes of selecting a desired transmission gear at least in part based on the wheel speeds of the vehicle. If the vehicle is being operated in a two-wheel drive mode, the vehicle speed is determined based on an average of the speeds of the un-driven wheels; if the vehicle is being operated in a four-wheel drive mode, the vehicle speed is determined based on the lowest of the four wheel speeds. Optionally, the wheel speeds are only used to determine vehicle speed if the Reverse range of the transmission has been engaged within a specified time interval, and otherwise the vehicle speed is determined based on an output speed of the transmission.

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Indianapolis, IN, United States of America

Andrew L Mitchell