Gm Global Technolgoy Operations, Inc.

Allison Transmission, Inc.

Peter Edwin Swingler

Jeff Shultz

Sean E Gleason

Edmond M Etchason

David W Wright

Reece R Fuehrer

Joseph H Hunter

William J Wegeng

Barry Lewis Ladd

A method for managing torque transmitting mechanism actuator output pressure under low supply pressure conditions is provided. The method is executable to control engagement of a torque transmitting mechanism during such conditions.

Control for managing actuator output pressure applied to a torque transmitting mechanism of a multi-speed transmission

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 improved transmission shift pattern control that preserves the attributes of a selected base shift pattern while dynamically adjusting the high throttle shift thresholds based on a measure of vehicle loading. Heavy vehicle loading is detected by recognizing a pattern of high engine throttle and lower than expected vehicle acceleration, and the high power shifting thresholds are dynamically adjusted based on the detected loading to automatically provide aggressive shifting in a heavily loaded vehicle without producing excessive shift cycling in a normally or lightly loaded vehicle. A throttle timer is used to detect a condition of sustained high throttle operation, and under such condition, an acceleration timer determines the duration of lower than expected acceleration. If the determined duration exceeds a threshold, a shift pattern override is activated until the acceleration rises above an exit threshold. The severity of the loading condition may be determined with multiple acceleration timers used to activate successively more aggressive shift pattern overrides.

Dynamic load compensation method for an automatic transmission shift pattern

In an automatic transmission having an electronic control, a double transition powered downshift to a target range requires the release of two off-going clutches and the engagement of two on-coming clutches. The shift begins by releasing one clutch and applying another to begin (but not complete) an upshift to a third range having a speed ratio lower than both the initial range and the target range so that first an input speed increase occurs followed by an input speed decrease (pull-down). The speed decrease triggers respective application and release of the other clutches to arrest the upshift and complete the downshift. Each clutch application and release occurs gradually under an open loop control. Slip of the first off-going clutch, pull-down, speed sync at the low gear ratio and a near sync condition are determined from turbine speed and output speed and are used to time pressure command changes to smoothly coordinate clutch releases and applications.

Sequenced control of double transition powered downshifting in an

A valve and closure assembly has a cover plate which attaches to a transmission housing to close the interior housing from atmosphere. A separator plate and a plurality of fluid valve assemblies are secured to the cover plate and disposed within the transmission housing. Fluid passages in the cover plate interconnect the valve assemblies. Passages in the separator plate direct fluid to passages in the transmission housing at the interface of the cover plate and transmission housing for distribution within the transmission housing to components disposed therein. Electrical wiring for the solenoids and an electrical connector are disposed on the cover plate so that a single electrical interconnection with the transmission can be utilized. Filters for both high pressure control fluid and low pressure cooling and lube fluid are secured on the cover plate.

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Carmel, IN, United States of America

Peter Edwin Swingler