Infrared occupancy sensor
First Claim
1. An occupancy sensor, comprising:
- an infrared sensor;
a variable bandpass filter operably coupled to the infrared sensor;
a digital potentiometer adapted to control a ratio of center frequency of the bandpass filter to a bandwidth of the bandpass filter; and
a controller operably coupled to the infrared sensor and the variable bandpass filter;
wherein the controller is adapted to;
filter the signals generated by the infrared sensor using the variable bandpass filter, andprocess the filtered signals to determine the presence or absence of an occupant within a defined region.
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Accused Products
Abstract
An occupancy sensor includes an infrared sensor, a variable bandpass filter operably coupled to the infrared sensor and a controller operably coupled to the infrared sensor and the variable bandpass filter. The bandpass filter includes digital potentiometers adapted to control a gain of the bandpass filter, the tuning of the bandpass filter, and the ratio of a center frequency of the bandpass filter to a bandwidth of the bandpass filter. The controller includes a bandpass filter engine to control the variable bandpass filter, a Doppler shift engine to characterize the signals filtered by the variable bandpass filter, and an occupancy sensing engine to determine the presence or absence of the occupant within the defined region. The controller is adapted to filter the signals generated by the infrared sensor and process the filtered signals to determine the presence or absence of an occupant within a defined region.
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Citations
28 Claims
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1. An occupancy sensor, comprising:
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an infrared sensor; a variable bandpass filter operably coupled to the infrared sensor; a digital potentiometer adapted to control a ratio of center frequency of the bandpass filter to a bandwidth of the bandpass filter; and a controller operably coupled to the infrared sensor and the variable bandpass filter; wherein the controller is adapted to; filter the signals generated by the infrared sensor using the variable bandpass filter, and process the filtered signals to determine the presence or absence of an occupant within a defined region.
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2. An occupancy sensor, comprising:
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an infrared sensor; a variable bandpass filter operably coupled to the infrared sensor comprising; a digital potentiometer adapted to control a gain of the bandpass filter; a digital potentiometer adapted to control a tuning of the bandpass filter; and a digital potentiometer adapted to control a ratio of a center frequency of the bandpass filter to a bandwidth of the bandpass filter; and a controller operably coupled to the infrared sensor and the variable bandpass filter comprising; a bandpass filter engine adapted to control the variable bandpass filter; a doppler shift engine adapted to characterize the signals filtered by the variable bandpass filter; and an occupancy sensing engine adapted to characterizations of the Doppler shift engine to determine the presence or absence of the occupant within the defined region; wherein the controller is adapted to; filter the signals generated by the infrared sensor using the variable bandpass filter, and process the filtered signals to determine the presence or absence of an occupant within a defined region. - View Dependent Claims (3, 4, 5, 6, 7)
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8. A method of operating an occupancy sensor, comprising:
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monitoring thermal energy within a defined region and generating signals representative of the thermal energy; filtering the signals using a variable bandpass filter; controlling a ratio of a center frequency to a bandwidth of the variable bandpass filter; sweeping the variable bandpass filter upwardly along a range of frequencies; then sweeping the variable bandpass filter downwardly along a range of frequencies; time averaging an amplitude of the filtered signals; comparing the time averaged amplitudes of the filtered signals; determining if a filtered signal indicates a source of thermal noise within the defined region; and determining if a filtered signal indicates a presence of an occupant within the defined region. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A system for operating an occupancy sensor, comprising:
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means for monitoring thermal energy within a defined region and generating signals representative of the thermal energy; means for filtering the signals using a variable bandpass filter; means for controlling a ratio of a center frequency to a bandwidth of the variable bandpass filter; means for sweeping the variable bandpass filter upwardly along a range of frequencies; means for then sweeping the variable bandpass filter downwardly along a range of frequencies; means for time averaging an amplitude of the filtered signals; means for comparing the time averaged amplitudes of the filtered signals; means for determining if a filtered signal indicates a source of thermal noise within the defined region; and means for determining if a filtered signal indicates a presence of an occupant within the defined region. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A computer-implemented method for operating an occupancy sensor, comprising the steps:
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monitoring thermal energy within a defined region to generate signals representative of the thermal energy within the defined region; filtering the signals using a variable bandpass filter; controlling a ratio of a center frequency to a bandwidth of the variable bandpass filter; sweeping the variable bandpass filter upwardly along a range of frequencies;
then sweeping the variable bandpass filter downwardly along a range of frequencies;time averaging an amplitude of the filtered signals; comparing the time averaged amplitudes of the filtered signals; determining if a filtered signal indicates a source of thermal noise within the defined region; and determining if a filtered signal indicates a presence of an occupant within the defined region. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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Specification