Method and apparatus for detecting and compensating for pressure transducer errors
First Claim
1. A system for controlling pressure in a transmission comprising:
- a valve for regulating operation of a hydraulic device;
a pressure transducer for detecting an output pressure of the valve, the pressure transducer configured to output a pressure reading representing the detected pressure for a range of pressures both below and above a predetermined threshold pressure and to communicate the detected pressure for each of the pressures, a first pressure reading taken at an operating condition in which the actual output pressure of the valve is substantially known;
a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer and a corrected pressure reading, the pressure measurement error computed using the first pressure reading and the substantially known actual output pressure of the valve and the corrected pressure reading computed using a first variable comprising a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading, and a second variable comprising the previously computed pressure measurement error; and
a valve controller for controlling the operation of the valve, the valve controller configured to receive as input from the microprocessor the corrected pressure reading and to output a control signal used to control the operation of the valve, the control signal formulated using the corrected pressure reading received from the microprocessor; and
a transmission control unit configured to receive as input from the microprocessor the previously computed pressure measurement error, the transmission control unit comprising logic for computing an adjusted command pressure computed using a desired pressure to be output from the valve and the previously computed pressure measurement error received from the microprocessor.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for detecting and compensating for pressure transducer errors includes a valve for regulating operation of a hydraulic device, a pressure transducer for detecting a pressure output from the valve, and a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer. The pressure transducer is configured to output a pressure reading representing the detected pressure. The pressure measurement error may be computed using a first pressure reading from the pressure transducer taken at an operating condition in which the actual output pressure of the valve is substantially known, together with the substantially known actual output pressure of the valve.
55 Citations
32 Claims
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1. A system for controlling pressure in a transmission comprising:
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a valve for regulating operation of a hydraulic device; a pressure transducer for detecting an output pressure of the valve, the pressure transducer configured to output a pressure reading representing the detected pressure for a range of pressures both below and above a predetermined threshold pressure and to communicate the detected pressure for each of the pressures, a first pressure reading taken at an operating condition in which the actual output pressure of the valve is substantially known; a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer and a corrected pressure reading, the pressure measurement error computed using the first pressure reading and the substantially known actual output pressure of the valve and the corrected pressure reading computed using a first variable comprising a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading, and a second variable comprising the previously computed pressure measurement error; and a valve controller for controlling the operation of the valve, the valve controller configured to receive as input from the microprocessor the corrected pressure reading and to output a control signal used to control the operation of the valve, the control signal formulated using the corrected pressure reading received from the microprocessor; and a transmission control unit configured to receive as input from the microprocessor the previously computed pressure measurement error, the transmission control unit comprising logic for computing an adjusted command pressure computed using a desired pressure to be output from the valve and the previously computed pressure measurement error received from the microprocessor. - View Dependent Claims (2, 3, 4)
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5. A system for controlling pressure in a transmission comprising:
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a valve for regulating operation of a hydraulic device; a pressure transducer for detecting an output pressure of the valve, the pressure transducer configured to output a pressure reading representing the detected pressure for a range of pressures both below and above a predetermined threshold pressure and to communicate the detected pressure for each of the pressures, a first pressure reading taken at an operating condition in which the actual output pressure of the valve is substantially known; a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer and a corrected pressure reading, the pressure measurement error computed using the first pressure reading and the substantially known actual output pressure of the valve and the corrected pressure reading computed using a first variable comprising a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading, and a second variable comprising the previously computed pressure measurement error, and the microprocessor is configured to output the previously computed pressure measurement error and a command pressure corresponding to a desired pressure to be output from the valve; a valve controller for controlling the operation of the valve, the valve controller configured to receive as input from the microprocessor the corrected pressure reading and to output a control signal used to control the operation of the valve, the control signal formulated using the corrected pressure reading received from the microprocessor; and an application specific integrated circuit configured to receive as input from the microprocessor the previously computed pressure measurement error, the application specific integrated circuit unit comprising logic for computing a corrected pressure reading using the previously computed pressure measurement error received from the microprocessor and the first pressure reading output from the pressure transducer. - View Dependent Claims (6, 7, 8)
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9. A system for controlling pressure in a transmission comprising:
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a valve for regulating operation of a hydraulic device; a pressure transducer for detecting an output pressure of the valve, the pressure transducer configured to output a pressure reading representing the detected pressure for a range of pressures both below and above a predetermined threshold pressure and to communicate the detected pressure for each of the pressures, a first pressure reading taken at an operating condition in which the actual output pressure of the valve is substantially known; a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer and a corrected pressure reading, the pressure measurement error computed using the first pressure reading and the substantially known actual output pressure of the valve and the corrected pressure reading computed using a first variable comprising a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading, and a second variable comprising the previously computed pressure measurement error; and a valve controller for controlling the operation of the valve, the valve controller configured to receive as input from the microprocessor the corrected pressure reading and to output a control signal used to control the operation of the valve, the control signal formulated using the corrected pressure reading received from the microprocessor; wherein the valve controller is configured to receive as input from the microprocessor the previously computed pressure measurement error and to output a control signal used to control the operation of the valve, the control signal formulated using the previously computed pressure measurement error received from the microprocessor. - View Dependent Claims (10, 11, 12)
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13. A system for controlling pressure in a transmission comprising:
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a valve for regulating operation of a hydraulic device; a pressure transducer for detecting an output pressure of the valve, the pressure transducer configured to output a pressure reading representing the detected pressure for a range of pressures both below and above a predetermined threshold pressure and to communicate the detected pressure for each of the pressures, a first pressure reading taken at an operating condition in which the actual output pressure of the valve is substantially known; a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer and a corrected pressure reading, the pressure measurement error computed using the first pressure reading and the substantially known actual output pressure of the valve and the corrected pressure reading computed using a first variable comprising a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading, and a second variable comprising the previously computed pressure measurement error; a valve controller for controlling the operation of the valve, the valve controller configured to receive as input from the microprocessor the corrected pressure reading and to output a control signal used to control the operation of the valve, the control signal formulated using the corrected pressure reading received from the microprocessor; and a transmission control unit is configured for outputting a command pressure corresponding to a desired pressure to be output from the valve; wherein the microprocessor is configured to output the previously computed pressure measurement error and a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading; wherein the valve controller is configured to receive as input from the transmission control unit the command pressure and as input from the microprocessor the previously computed pressure measurement error and the second pressure reading, the valve controller configured to output a control signal used to control the operation of the valve, the control signal formulated using the previously computed pressure measurement error received from the microprocessor and at least one of the command pressure and the second pressure reading. - View Dependent Claims (14, 15, 16)
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17. A system for controlling pressure in a transmission comprising:
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a valve for regulating operation of a hydraulic device; a pressure transducer for detecting an output pressure of the valve, the pressure transducer configured to output a pressure reading representing the detected pressure for a range of pressures both below and above a predetermined threshold pressure and to communicate the detected pressure for each of the pressures, a first pressure reading taken at an operating condition in which the actual output pressure of the valve is substantially known; a microprocessor comprising logic for computing a pressure measurement error of the pressure transducer and a corrected pressure reading, the pressure measurement error computed using the first pressure reading and the substantially known actual output pressure of the valve and the corrected pressure reading computed using a first variable comprising a second pressure reading received from the pressure transducer taken subsequent to the first pressure reading, and a second variable comprising the previously computed pressure measurement error; a valve controller for controlling the operation of the valve, the valve controller configured to receive as input from the microprocessor the corrected pressure reading and to output a control signal used to control the operation of the valve, the control signal formulated using the corrected pressure reading received from the microprocessor; and a transmission control unit is configured to receive as input from the microprocessor the previously computed pressure measurement error and to output a command pressure corresponding to the desired pressure to be output from the valve and the previously computed pressure measurement error received from the microprocessor; wherein the microprocessor is configured to output the previously computed pressure measurement error and a second pressure reading received from the pressure transducer, the second pressure reading taken subsequent to the first pressure reading; wherein the valve controller is configured to receive as input from the transmission control unit the command pressure and the previously computed pressure measurement error, and from the microprocessor the second pressure reading, the valve controller configured to output a control signal used to control the operation of the valve, the control signal formulated using the command pressure and the previously computed pressure measurement error received from the transmission control unit and the second pressure reading received from the microprocessor. - View Dependent Claims (18, 19, 20)
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21. A method for automatically detecting and compensating for measurement error of a pressure transducer comprising:
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operating a pump to produce a flow of pressurized fluid for delivery to a valve; arranging the valve in a configuration known to substantially produce a predetermined output pressure of the valve while operating the pump; using the pressure transducer to detect an output pressure of a valve, the pressure transducer configured to output a pressure reading representing the detected pressure; obtaining a first pressure reading while operating the pump with the valve arranged in the configuration known to substantially produce a predetermined output pressure of the valve; computing a first pressure measurement error using the first pressure reading and the substantially known output pressure of the valve occurring at the time the first pressure reading is obtained; obtaining a second pressure reading subsequent to the first pressure reading; and computing a first corrected pressure reading using the first pressure reading and the first pressure measurement error. - View Dependent Claims (22, 23, 24)
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25. A method for automatically detecting and compensating for measurement error of a pressure transducer comprising:
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operating a pump to produce a flow of pressurized fluid for delivery to a valve; arranging the valve in a configuration known to substantially produce a predetermined output pressure of the valve while operating the pump; using the pressure transducer to detect an output pressure of a valve, the pressure transducer configured to output a pressure reading representing the detected pressure; obtaining a first pressure reading while operating the pump with the valve arranged in the configuration known to substantially produce a predetermined output pressure of the valve; computing a first pressure measurement error using the first pressure reading and the substantially known output pressure of the valve occurring at the time the first pressure reading is obtained; and computing a first compensated command pressure using a desired pressure to be output from the valve and the first pressure measurement error. - View Dependent Claims (26, 27, 28)
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29. A method for automatically detecting and compensating for measurement error of a pressure transducer comprising:
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operating a pump to produce a flow of pressurized fluid for delivery to a valve; arranging the valve in a configuration known to substantially produce a predetermined output pressure of the valve while operating the pump; using the pressure transducer to detect an output pressure of a valve, the pressure transducer configured to output a pressure reading representing the detected pressure; obtaining a first pressure reading while operating the pump with the valve arranged in the configuration known to substantially produce a predetermined output pressure of the valve; and computing a first pressure measurement error using the first pressure reading and the substantially known output pressure of the valve occurring at the time the first pressure reading is obtained; wherein the first pressure reading is obtained when the valve is closed. - View Dependent Claims (30, 31, 32)
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Specification