IMPULSE ANALYSIS FOR FLOW SENSOR-BASED FLUID CONTROL SYSTEM
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Accused Products
Abstract
A fluid flow control system using flow rate changes to extract additional information from an in-line flow sensor. The system provides the ability to determine a position of a movable flow sensor element of a flow sensor by illuminating a photosensitive pixel array with a light source to create a first set of pixel intensity values, introducing an abrupt change to the fluid driving pressure, illuminating the photosensitive pixel array with a light source to create a second set of pixel intensity values, and calculating the difference between the first and second sets of pixel intensity values as a function of pixel position.
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Citations
35 Claims
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1-18. -18. (canceled)
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19. A flow sensor for a flow control system for controlling flow of a liquid, the flow control system having a flow passageway, the flow sensor comprising:
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a sensor element movably positioned in the flow passageway, wherein a position of the sensor element in the flow passageway is responsive to a flow rate of the liquid in the flow passageway and to a viscosity of the liquid, and further wherein the flow rate is responsive to a fluid driving pressure and a systemic flow resistance in the flow control system; a sensor for generating a signal representative of a position of the sensor element in the flow passageway; and a processor coupled to the sensor for receiving the signal from the sensor before and after an abrupt change in the fluid driving pressure to calculate any one or more of; the position of the sensor element in the flow passageway before the abrupt change in the fluid driving pressure; the position of the sensor element in the flow passageway after the abrupt change in the fluid driving pressure; a change in position of the sensor element in the flow passageway; a rate of change in position of the sensor element in the flow passageway; the flow rate before the abrupt change in the fluid driving pressure; the flow rate after the abrupt change in the fluid driving pressure; a change in the flow rate; the viscosity of the liquid; and the systemic flow resistance. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
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20. A method for determining flow information in a flow control system, the flow control system for controlling flow of a liquid, the flow control system having a flow passageway, a sensor element movably positioned in the flow passageway, and a sensor for generating a signal representative of a position of the sensor element in the flow passageway, wherein a position of the sensor element in the flow passageway is responsive to a flow rate of the liquid in the flow passageway and to a viscosity of the liquid, and further wherein the flow rate is responsive to a fluid driving pressure and a systemic flow resistance in the flow control system, the method comprising:
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introducing an abrupt change in fluid driving pressure; prior to introducing the abrupt change in fluid driving pressure, sampling the signal from the sensor to obtain a first measurement of sensor element position; after introducing the abrupt change in fluid driving pressure, sampling the signal from the sensor to obtain a second measurement of sensor element position; and determining a difference between the first measurement and the second measurement. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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Specification