Method and apparatus for controlling the operation of a pump
First Claim
1. A method of controlling the rate at which fuel is supplied to an engine by a fuel pump, said method comprising the steps of determining a series of curves which indicate the manner in which pump output varies with pump operating speed, determining at a first time which one curve of the series of curves is representative of the manner in which fuel pump output varies with pump speed by simultaneously sensing fuel pump operating speed and output pressure during engine operation, and thereafter varying the fuel pump operating speed in accordance with the one curve to provide a desired variation in fuel pump output to the engine.
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Abstract
An improved method and apparatus is provided to control the rate at which fuel is supplied to an engine by a fuel pump. The fuel pump has an output pressure which varies with pump operating speed in accordance with different curves of a series of curves. In order to determine which curve of the series of curves is representative of the manner in which the fuel pump output varies with pump speed at one time, the fuel pump operating speed and output pressure are simultaneously sensed to determine a point on an initial curve. The fuel pump operating speed is subsequently varied in accordance with the initial curve to provide a desired variation in fuel pump output to the engine. The fuel pump operating speed and output pressure are periodically simultaneously sensed to determine if the fuel pump output still varies in accordance with the initial curve or has changed to a second curve of the series of curves. If it is determined that a second curve is representative of the manner in which the fuel pump output varies with pump speed, the fuel pump operating speed is subsequently varied in accordance with the second curve.
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Citations
37 Claims
- 1. A method of controlling the rate at which fuel is supplied to an engine by a fuel pump, said method comprising the steps of determining a series of curves which indicate the manner in which pump output varies with pump operating speed, determining at a first time which one curve of the series of curves is representative of the manner in which fuel pump output varies with pump speed by simultaneously sensing fuel pump operating speed and output pressure during engine operation, and thereafter varying the fuel pump operating speed in accordance with the one curve to provide a desired variation in fuel pump output to the engine.
- 8. A method comprising the steps of operating an engine, operating a fuel pump to give a predetermined fuel flow rate to the engine, varying the rate of flow of fuel to the engine by varying the speed of operation of the fuel pump, sensing a fuel pump operating characteristic each time a predetermined condition occurs, and changing the speed at which the fuel pump is operated to give the predetermined fuel flow rate to the engine in response to a sensing that the fuel pump operating characteristic has changed.
- 14. A method of controlling the rate at which fluid is discharged from a pump and motor assembly having a fluid output which varies with variations in a pump and motor assembly operating characteristic in accordance with different curves of a series of curves at different times, said method comprising the steps of determining at a first time which curve of the series of curves is representative of the manner in which pump output varies with variations in the pump and motor assembly operating characteristic, said step of determining which curve is representative of the manner in which pump output varies with variations in the pump and motor assembly operating characteristic at the first time includes the step of locating a point on a first curve of the series of curves by sensing pump output and the operating characteristic of the pump and motor assembly at the first time, thereafter varying the pump and motor assembly operating characteristic in accordance with the first curve to provide a desired pump output, performing said steps of sensing the pump output and the operating characteristic of the pump and motor assembly at a second time to determine if the pump output still varies in accordance with the first curve or has changed to a second curve of the series of curves, and subsequently varying the pump and motor assembly operating characteristic in accordance with the second curve to provide a desired pump output if it is determined that the second curve is representative of the manner in which pump output varies with variations in the pump and motor assembly operating characteristic.
- 19. A method of controlling the rate at which fuel is supplied to an engine by a pump having a fluid output which varies with fuel pump operating speed in accordance with different curves at different times, said method comprising the steps of operating a motor to drive the fuel pump to supply fuel to the engine during operation of the engine, providing a first signal which varies as a function of variations in a desired fuel flow rate to the engine during operation of the engine, providing a second signal which represents the fuel flow rate to the engine during operation of the engine, comparing the first and second signals and providing a third signal which varies as a function of the difference between the desired fuel flow rate represented by the first signal and the fuel flow rate represented by the second signal, varying the speed at which the motor drives the fuel pump as a function of variations in the third signal, sensing fuel pump output and operating speed each time a predetermined event occurs during operation of the engine, each time the predetermined event occurs during operation of the engine performing the step of determining which curve of the series of curves is representative of the manner in which fuel pump output varies with fuel pump operating speed, and varying the second signal as a function of fuel pump operating speed and the curve determined to be representative of the manner in which fuel pump output varies with fuel pump operating speed the last time the predetermined event occurred during operation of the engine.
- 21. An apparatus for use in controlling the rate at which fuel is supplied to an engine by a fuel pump, said apparatus comprising a fuel pump, control means for determining a first time which one curve of a series of curves is representative of the manner in which fuel pump output varies with pump speed during engine operation, said control means including sensor means for simultaneously sensing fuel pump operating speed and output pressure at the first time during engine operation, and drive means connected with said control means and said fuel pump for varying fuel pump operating speed in accordance with the one curve to provide a desired variation in fuel pump output to the engine.
- 28. An apparatus comprising an engine, a fuel pump connected in fluid communication with said engine, said fuel pump having an output flow rate which varies as a function of variations in the speed at which the fuel pump is driven and as a function of variations in fuel pump operating characteristics, variable speed motor means connected with said fuel pump for driving said fuel pump, and control means for effecting operation of said motor means to drive said fuel pump at any one of a plurality of speeds to supply fuel to said engine at a desired one of a plurality of fuel flow rates, said control means including sensor means for sensing a fuel pump operating characteristic, first means for providing a first signal which varies as a function of variations in the fuel pump operating characteristic, second means for providing a second signal which varies as a function of variations in the desired fuel flow rate to the engine, third means for providing a third signal which varies as a function of variations in the first and second signals, and means for effecting operation of said motor means to vary the speed at which said pump is driven as a function of said third signal.
- 33. An apparatus comprising an engine, a pump and motor assembly, said pump and motor assembly including a fuel pump connected in fluid communication with said engine and a motor connected with said fuel pump, said fuel pump having an output which varies as a function of variations in an operating characteristic of said pump and motor assembly and as a function of variations in different curves of a series of curves, and control means connected with said pump and motor assembly for controlling operation of said pump and motor assembly to supply fuel to the engine at a desired rate during operation of the engine, said control means including first sensor means for providing a first signal which varies as a function of variations in fuel pump output, second sensor means for providing a second signal which varies as a function of variations in the operating characteristic of said pump and motor assembly, means responsive to said first and second signals for determining which one curve of the series of curves is representative of the manner in which fuel pump output varies with variations in the operating characteristic of said pump and motor assembly and for providing a third signal which varies as a function of variations in the one curve of the series of curves with variations in the operating characteristic of said pump and motor assembly, means for providing a fourth signal which varies as a function of desired fuel flow rate to said engine, and comparator means for comparing said third and fourth signals and effecting operation of said motor to vary the fuel pump output as a function of the difference between said third and fourth signals.
Specification