METHOD AND APPARATUS TO CONTROL CLUTCH FILL PRESSURE IN AN ELECTRO-MECHANICAL TRANSMISSION
First Claim
8. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member via selective application of a plurality of hydraulically-applied torque transfer clutches, said method comprising:
- selecting a preferred command pressure in a pressure control solenoid fluidly connected to one of said clutches, said selecting comprisingiteratively filling said clutch with a calibration command pressure,wherein said calibration command pressure decreases with each iteration,monitoring pressure switch cycle times for a pressure switch fluidly connected to said pressure control solenoid and configured to generate an indication when said pressure control solenoid is in a full feed state, andselecting from said calibration command pressures said preferred command pressure based upon identifying a transition between differences in said calibration command pressures; and
utilizing said preferred command pressure in subsequent operation of said clutch.
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Accused Products
Abstract
A method to control a powertrain including a transmission, an engine, and an electric machine includes applying through a series of clutch fill events a series of incrementally changing command pressures in a pressure control solenoid controllably connected to a clutch within the transmission, monitoring a pressure switch fluidly connected to the pressure control solenoid and configured to indicate when the pressure switch is in a full feed state, determining changes in cycle times of the pressure switch corresponding to sequential applications of the series of incrementally changing command pressures, selecting a preferred command pressure to achieve a transient state in the clutch based upon the changes in pressure switch cycle times, and controlling the clutch based upon the preferred command pressure.
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Citations
13 Claims
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8. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member via selective application of a plurality of hydraulically-applied torque transfer clutches, said method comprising:
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selecting a preferred command pressure in a pressure control solenoid fluidly connected to one of said clutches, said selecting comprising iteratively filling said clutch with a calibration command pressure, wherein said calibration command pressure decreases with each iteration, monitoring pressure switch cycle times for a pressure switch fluidly connected to said pressure control solenoid and configured to generate an indication when said pressure control solenoid is in a full feed state, and selecting from said calibration command pressures said preferred command pressure based upon identifying a transition between differences in said calibration command pressures; and utilizing said preferred command pressure in subsequent operation of said clutch. - View Dependent Claims (1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13)
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10-1. The apparatus of claim 9, wherein said series of incrementally changing command pressures comprises a series of incrementally decreasing command pressures.
Specification