Adaptive faucet controller measuring proximity and motion
First Claim
1. In an automatic faucet controller comprising an emitter emitting electromagnetic radiation, a detector detecting said electromagnetic radiation and having as an output an electrical signal corresponding to the intensity of said detected radiation, and an electrically operated valve, said controller acting to open said valve when a user'"'"'s hands proximate said faucet reflect said electromagnetic radiation from said emitter to said detector and thereby provide a said signal exceeding a threshold value, an improvement comprisingmeans for storing a water-offset value equal to said signal corresponding to the intensity of said radiation reflected only from a stream of water from said faucet at a first predetermined time, andmeans for subtracting said water-offset value from said signal at a second time, subsequent to said first time, when said valve is open, andmeans for holding said valve open if said signal, less said water-offset value, exceeds said threshold value.
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Abstract
An electronically controlled automatic faucet has a pulsed infrared beam intersecting the water stream discharged by the faucet. Infrared signals reflected from the water stream are thus detected in addition to any signals reflected from a user'"'"'s hand(s). A reasonable approximation of the signal received from the water stream alone is subtracted from the sum of all detected signals whenever water is flowing in order to provide a compensated proximity signal. This compensation method, which may be implemented in hardware or software, prevents a shift in the sensor'"'"'s sensitivity during periods when water is flowing, and eliminates the possibility that water flow might "lock-on" once initiated. Compensating for water flow improves sensor performance by allowing the infrared detection field to encompass a larger volume of space where a user'"'"'s hands might be found. In addition, the same, or similar, hardware can be used to detect a user'"'"'s hand motion. The disclosed motion detection method can be used alone, or it can be used as an adjunct to the water stream compensation method, in which case it prevents extended intervals of water flow that could otherwise occur when foreign objects are left in view of the sensor.
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Citations
29 Claims
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1. In an automatic faucet controller comprising an emitter emitting electromagnetic radiation, a detector detecting said electromagnetic radiation and having as an output an electrical signal corresponding to the intensity of said detected radiation, and an electrically operated valve, said controller acting to open said valve when a user'"'"'s hands proximate said faucet reflect said electromagnetic radiation from said emitter to said detector and thereby provide a said signal exceeding a threshold value, an improvement comprising
means for storing a water-offset value equal to said signal corresponding to the intensity of said radiation reflected only from a stream of water from said faucet at a first predetermined time, and means for subtracting said water-offset value from said signal at a second time, subsequent to said first time, when said valve is open, and means for holding said valve open if said signal, less said water-offset value, exceeds said threshold value.
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9. In a motion-sensing controller for a faucet having an output stream of water reflecting pulsed electromagnetic radiation from an emitter thereof to a detector thereof, said detector having an output signal value corresponding to the intensity of said pulsed electromagnetic radiation, said controller opening an electrically actuated valve if said output signal varies by more than a first predetermined amount during a predetermined interval, an improvement comprising
means for storing a water-offset value equal to the output signal value corresponding to the intensity of said radiation reflected only from said stream of water, means for subtracting said water-offset value from the output signal value at a time when said valve is open, thereby forming a difference value, said controller holding said valve open if the difference value exceeds a second predetermined amount.
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12. A method of operating a faucet controller comprising an emitter of optical radiation, a detector of optical radiation having as an output an electrical signal corresponding to the intensity of said radiation received, a computer having computer memory associated therewith, and an electrically actuated valve controlled by said computer, said method comprising the steps of
a) storing, in a first location in said computer memory, a water-offset value equal to said signal corresponding to radiation reflected only from a stream of water from said faucet, b) storing, in a second location in said computer memory, a threshold value, c) forming a first algebraic difference by subtracting said threshold value from said signal output at a first time and opening said valve if said first difference is greater than zero, d) forming a second algebraic difference by subtracting the sum of said threshold value and said water-offset value from said signal at a second time subsequent to said first time, and e) closing said valve if said second difference is less than zero.
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15. A method of operating a controller for a faucet, said controller comprising an emitter of optical radiation, a detector of optical radiation having as an output an electrical signal corresponding to the intensity of radiation received, signal processing circuitry processing said detected signal, and an electrically actuated valve controlled by said signal processing circuitry, a stream of water from said faucet reflecting said radiation from said emitter to said detector, said method comprising the steps of
a) comparing said detected signal to a predetermined threshold value and opening said valve if said detected signal exceeds said threshold, b) forming a difference signal by subtracting from said detected signal a water-offset value equal to said signal corresponding to radiation reflected only from said stream of water, c) comparing said difference signal to said threshold value and closing said valve if said difference signal does not exceed said threshold value.
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18. A method of adapting an automatic faucet controller to environmental changes, the controller comprising an emitter emitting electromagnetic radiation, a detector detecting reflected electromagnetic radiation from the emitter, the detector having as an output an electrical signal corresponding to the intensity of the detected radiation;
- and an electrically operated valve having open and closed states, the controller opening the valve when a user'"'"'s hands reflect a portion of the electromagnetic radiation from the emitter to the detector and are thereby detected proximate the faucet, the controller comprising a microprocessor having computer memory operatively associated therewith, the method comprising the steps of
a) measuring a first signal value at a first time when the valve is closed and storing the first signal value in the memory as a stored background value, b) waiting for a predetermined interval during which the difference between the detector output and the stored background value never exceeds a predetermined value, c) measuring the current background signal value at the expiration of the predetermined interval, and d) replacing, in the computer memory, the stored background value with an adjusted background value differing from the replaced background value by a predetermined increment, the difference between the adjusted background value and the current background value less than the difference between the replaced background value and the current background value. - View Dependent Claims (19, 20, 21, 22)
- and an electrically operated valve having open and closed states, the controller opening the valve when a user'"'"'s hands reflect a portion of the electromagnetic radiation from the emitter to the detector and are thereby detected proximate the faucet, the controller comprising a microprocessor having computer memory operatively associated therewith, the method comprising the steps of
- 23. A motion-sensing faucet controller comprising an emitter and a detector of pulsed electromagnetic radiation, the detector having an output signal corresponding to the intensity of the pulsed electromagnetic radiation reflected from an object proximate the faucet, the controller comprising timing means and memory means, the controller receiving the output signal from the detector and storing, in the memory means, a value equal to the output signal at a first time, the controller subsequently opening an electrically actuated valve at a second time when the output signal varies from the stored value by more than a predetermined amount, the timing means initiating a first interval having a first predetermined duration when the output signal varies by more than the first predetermined amount from the stored value, the controller holding the valve open during the duration of the first interval and, if the output signal differs from the stored value by less than the predetermined amount at all times during the first interval, closing the valve at the expiration of the first interval and holding the valve closed for a second interval having a second predetermined duration.
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26. A method of adapting an automatic faucet controller to environmental changes, the controller comprising an emitter emitting electromagnetic radiation;
- a detector detecting electromagnetic radiation from the emitter, the detector having as an output an electrical signal corresponding to the intensity of the detected radiation; and
an electrically operated valve having open and closed states, the controller opening the valve when a user'"'"'s hands reflect a portion of the electromagnetic radiation from the emitter to the detector and are thereby detected proximate the faucet, the controller comprising a microprocessor having computer memory operatively associated therewith, the method comprising the steps of;a) storing a predetermined value in the memory at a first time prior to a time of installation, b) installing the controller and waiting for a predetermined interval; c) measuring the current value of the signal at the expiration of the predetermined interval; and d) replacing, in the computer memory, the stored predetermined value with a first background value differing from the replaced predetermined value by a predetermined increment, the difference between the first background value and the current value less than the difference between the replaced value and the current value. - View Dependent Claims (27)
- a detector detecting electromagnetic radiation from the emitter, the detector having as an output an electrical signal corresponding to the intensity of the detected radiation; and
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28. A method of operating an automatic faucet controller comprising an emitter emitting electromagnetic radiation, a detector detecting electromagnetic radiation from the emitter, the detector having as an output an electrical signal corresponding to the intensity of the detected radiation;
- and an electrically operated valve having open and closed states, the controller opening the valve when a user'"'"'s hands reflect a portion of the electromagnetic radiation from the emitter to the detector and are thereby detected proximate the faucet, the controller comprising a microprocessor having computer memory operatively associated therewith, the method comprising the steps of
a) resetting the microprocessor; b) controlling the valve to be in the closed state; c) waiting a first predetermined interval; c) storing the signal corresponding to the intensity of the detected radiation at the end of the first predetermined interval in the computer memory as a background value; and d) thereafter opening the valve only when the signal exceeds the background value by a first predetermined amount. - View Dependent Claims (29)
- and an electrically operated valve having open and closed states, the controller opening the valve when a user'"'"'s hands reflect a portion of the electromagnetic radiation from the emitter to the detector and are thereby detected proximate the faucet, the controller comprising a microprocessor having computer memory operatively associated therewith, the method comprising the steps of
Specification