METHOD AND APPARATUS TO CONTROL HYDRAULIC LINE PRESSURE IN AN ELECTRO-MECHANICAL TRANSMISSION
First Claim
1. Method for controlling hydraulic line pressure of a hydraulic control system in an electromechanical transmission adapted to selectively transmit mechanical power to an output member, said method comprising:
- determining an available flow from a main hydraulic pump;
determining an available flow from an auxiliary hydraulic pump;
determining a flow consumption of functions served by said hydraulic control system;
determining an estimated hydraulic line pressure based upon said flow from said main hydraulic pump, said flow from said auxiliary hydraulic pump, and said flow consumption;
determining a desired hydraulic line pressure to fulfill the functions served by said hydraulic control system;
comparing said desired hydraulic line pressure to said estimated hydraulic line pressure; and
controlling said main hydraulic pump and said auxiliary hydraulic pump based upon said comparing said desired hydraulic line pressure to said estimated hydraulic line pressure.
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0 Petitions
Accused Products
Abstract
A method for controlling hydraulic line pressure of a hydraulic control system in transmission includes determining an available flow from a plurality of hydraulic pumps, determining a flow consumption of functions served by the hydraulic control system, determining an estimated hydraulic line pressure based upon the flow from the pumps and the flow consumption, determining a desired hydraulic line pressure, and controlling the hydraulic pumps based upon the desired hydraulic line pressure and the estimated hydraulic line pressure.
223 Citations
17 Claims
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1. Method for controlling hydraulic line pressure of a hydraulic control system in an electromechanical transmission adapted to selectively transmit mechanical power to an output member, said method comprising:
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determining an available flow from a main hydraulic pump; determining an available flow from an auxiliary hydraulic pump; determining a flow consumption of functions served by said hydraulic control system; determining an estimated hydraulic line pressure based upon said flow from said main hydraulic pump, said flow from said auxiliary hydraulic pump, and said flow consumption; determining a desired hydraulic line pressure to fulfill the functions served by said hydraulic control system; comparing said desired hydraulic line pressure to said estimated hydraulic line pressure; and controlling said main hydraulic pump and said auxiliary hydraulic pump based upon said comparing said desired hydraulic line pressure to said estimated hydraulic line pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. Method for controlling hydraulic line pressure of a hydraulic control system including main and auxiliary hydraulic pumps providing hydraulic oil to functions comprising transmission clutch control, electric machine cooling, and lubrication in an electromechanical transmission adapted to selectively transmit mechanical power to an output member, said method comprising:
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monitoring factors affecting hydraulic pump operation including hydraulic oil temperature, hydraulic pump speeds, and hydraulic line back pressure; determining available flow from each hydraulic pump in said hydraulic control system; modeling flow consumption of said functions; determining an estimated hydraulic line pressure based upon said flow from said hydraulic pumps and said flow consumption; determining a desired hydraulic line pressure to fulfill functions served by said hydraulic control system, wherein said desired hydraulic line pressure is based upon a minimum functional hydraulic line pressure, a maximum achievable hydraulic line pressure, and said modeling said flow consumption of said functions; and controlling said main hydraulic pump and said auxiliary hydraulic pump to meet said desired hydraulic pressure based upon said estimated hydraulic line pressure.
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15. Apparatus for controlling hydraulic line pressure of a hydraulic control system in an electromechanical transmission adapted to selectively transmit mechanical power to an output member, said method comprising:
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a main pump flow module determining an available flow from a main hydraulic pump; an auxiliary pump flow module determining an available flow from an auxiliary hydraulic pump; a line pressure estimation module determining an estimated hydraulic line pressure based upon said flow from said main hydraulic pump, said flow from said auxiliary hydraulic pump, transmission clutch flow requirements, and a transmission oil temperature; and a pump control module issuing pump commands to said main hydraulic pump and said auxiliary hydraulic pump based upon a desired hydraulic line pressure and said estimated hydraulic line pressure. - View Dependent Claims (16, 17)
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Specification