US 8,265,838 B2Granted

System and method for controlling solenoid pressure

AssigneeGM Global Technology Operations LLC

InventorThomas H. Wilson

Life of this patent

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Abstract

A system for calibrating an input electrical signal to an individual pressure control device includes the steps of providing a target pressure-to-current (P/I) threshold, providing a lower estimated P/I threshold, and providing an estimated P/I curve that passes between the target P/I threshold and the lower estimated P/I threshold. Next, the method determines a lower actual P/I threshold at a pressure equal to the pressure at the lower estimated P/I threshold. A maximum offset current is calculated from the difference between the currents at the lower actual P/I threshold and the lower estimated P/I threshold. Finally, the system calculates a calibrated P/I curve. The calibrated P/I curve includes the target P/I threshold and the lower actual P/I threshold. The slope of the calibrated P/I curve is calculated as a proportional value of the maximum offset current.

Claims17

Dependent claims

A system in a transmission for calibrating an input signal sent to a pressure control device with an output pressure of a hydraulic fluid provided by the pressure control device, the system comprising:

a temperature sensor for sensing a temperature of the hydraulic fluid within the transmission;
a pressure control device for controlling an output pressure of the hydraulic fluid;
and
a controller in communication with the temperature sensor and the pressure control device, the controller having control logic including a first control logic for providing a target threshold that comprises a first actual input signal operable to produce a first output pressure, a second control logic for providing a lower estimated threshold that comprises a first estimated input signal estimated to produce a second output pressure, a third control logic for providing an estimated signal-to-pressure relationship that provides a plurality of estimated input signals estimated to produce a plurality of output pressures, the estimated signal-to-pressure relationship including the target threshold and the lower estimated threshold, a fourth control logic for determining a lower target threshold that comprises a second actual input signal required to produce the second output pressure, a fifth control logic for calculating a signal offset from the difference between the second actual input signal and the first estimated input signal, and a sixth control logic for determining a calibrated signal-to-pressure relationship that provides a plurality of calibrated input signals operable to produce the plurality of output pressures, wherein the plurality of calibrated input signals are proportionally offset from the plurality of estimated input signals using a proportional value of the signal offset.

1 more element

A system for operating a device in a transmission using hydraulic fluid, the system comprising:

a temperature sensor for sensing a temperature of the hydraulic fluid within the transmission;
a pressure control device for controlling an output pressure of the hydraulic fluid to the device;
and
a controller in communication with the temperature sensor and the pressure control device, the controller having control logic including a first control logic for determining whether the device should be activated, a second control logic for generating a requested output pressure required to activate the device, a third control logic for receiving a signal from the temperature sensor indicative of the temperature of the hydraulic fluid, a fourth control logic for providing an estimated input signal to provide the requested output pressure from the pressure control device that is adjusted for the temperature of the hydraulic fluid, a fifth control logic for providing a target threshold that comprises a first actual input signal operable to produce a first output pressure, a sixth control logic for providing a lower estimated threshold that comprises a first estimated input signal estimated to produce a second output pressure, a seventh control logic for providing an estimated signal-to-pressure relationship that provides a plurality of estimated input signals estimated to produce a plurality of output pressures, the estimated signal-to-pressure relationship including the target threshold and the lower estimated threshold, an eighth control logic for determining a lower target threshold that comprises a second actual input signal required to produce the second output pressure, a ninth control logic for calculating a signal offset from the difference between the second actual input signal and the first estimated input signal, a tenth control logic for determining a calibrated signal-to-pressure relationship that provides a plurality of calibrated input signals operable to produce the plurality of output pressures, wherein the plurality of calibrated input signals are proportionally offset from the plurality of estimated input signals using a proportional value of the signal offset, and an eleventh control logic for using the calibrated signal-to-pressure relationship to determine a calibrated input signal required to produce the requested output pressure.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 13/443,225Filed 10 Apr 2012 · division
Priority: 9 May 2008
Published: US 2012/0197502 A12 Aug 2012
Granted: 11 Sep 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

F16H 61/0251
The signals being electric: elements specially adapted for electric control units, e.g. valves for converting electrical signals to fluid signals
F16H 59/72
Inputs being a function of gearing status: dependent on oil characteristics, e.g. temperature, viscosity
F16H 2342/10
Calibrating: calibrating valves
F16H
Gearing

Family

Application61/051,780Us provisional application · filed 9 May 2008
Application12/413,245Parent of this division · filed 27 Mar 2009
US 2012/0197502 A1Pre-grant publication · published 2 Aug 2012
US 8,151,620 B2Parent of this division
US 2009/0281698 A1Published application
US 8,265,838 B2This patent

From the US filing history. Foreign family members aren’t listed.