Systems and methods for providing hub-based motion detection using distributed, light-based motion sensors
11693383 · 2023-07-04
Assignee
Inventors
Cpc classification
G01R19/165
PHYSICS
F24F2120/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F2110/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F11/56
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F11/62
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F2120/12
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02B20/40
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H05B47/11
ELECTRICITY
F24F2120/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H05B47/115
ELECTRICITY
F24F11/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
G05B2219/2642
PHYSICS
F24F11/64
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F2130/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F24F11/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F11/62
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
G01R19/165
PHYSICS
Abstract
Systems and methods are provided herein for determining motion in a volume using a lighting based sensor. A status of a light is determined with which a motion sensor is associated. Motion measurements are received from the motion sensor. Based on the motion measurements, a motion score is determined. A room status is adjusted based on the motion score.
Claims
1. A method of determining motion in a volume using a lighting based sensor implemented by one or more data processors forming one or more computing devices, the method comprising: determining, by at least one data processor, a status of a light with which a motion sensor is associated; receiving, by at least one data processor, motion measurements from the motion sensor; determining, by at least one data processor, based on the motion measurements, a motion score, wherein determining the motion score further comprises: determining a motion signal representation of the motion measurements; calculating the motion score based on at least one of a number of transitions in the motion signal representation and a number of smoothed reversals in the motion signal representation, wherein calculating the motion score comprises: comparing a data point of the motion signal representation to a most-extreme value variable; replacing the most-extreme valuable variable with the data point if the data point exceeds the most-extreme value variable; identifying a next data point below the most-extreme value variable as one of the smoothed reversals in the motion signal representation; and averaging corresponding voltages of recent smoothed reversals to determine the motion score; adjusting, by at least one data processor, a room status control based on the motion score; and adjusting, by at least one data processor, a room light level or a room temperature based on the room status control.
2. The method of claim 1, wherein averaging comprises an exponentially weighted moving average.
3. The method of claim 2, wherein determining the motion score further comprises generating a smoothed motion signal representation, by multiplying the motion signal representation by a smoothing factor.
4. The method of claim 3, wherein determining the motion score further comprises averaging absolute differences between each sample.
5. The method of claim 1, wherein determining the motion signal representation comprises a time-smoother variance of the motion measurements.
6. The method of claim 1, wherein the motion type comprises a major motion, a minor motion, or no motion.
7. The method of claim 1, further comprising transmitting the motion score from the light to a remote location.
8. The method of claim 7, wherein the remote location comprises an HVAC system.
9. The method of claim 1, wherein the room status control comprises a light level or temperature setting.
10. The method of claim 1, wherein calculating the motion score based on a number of transitions in the motion signal representation comprises: picketing a subset of samples of the motion signal representation over a constant interval; determining a delta-voltage between each sample of the subset of samples; and comparing the delta-voltage to a predetermined threshold, wherein the motion score is based on a number of delta-voltages exceeding the predetermined threshold.
11. The method of claim 1, wherein the smoothed reversals are weighted based on a signal strength of the motion signal representation.
12. The method of claim 1, wherein calculating the motion score is further based on at least one of a slew rate of the motion signal representation.
13. A method of determining motion in a volume using a lighting based sensor implemented by one or more data processors forming one or more computing devices, the method comprising: determining, by at least one data processor, a status of a light with which a motion sensor is associated; receiving, by at least one data processor, motion measurements from the motion sensor; determining, by at least one data processor, based on the motion measurements, a motion score, wherein determining the motion score further comprises: determining a motion signal representation comprising a plurality of frequencies; removing a bias from the motion signal representation; generating a guard band around a midline of the motion signal representation; and determining a number of zero crossings from the motion signal representation, wherein a zero crossing occurs when the signal exceeds the guard band and the motion score comprises the number of zero crossings; adjusting, by at least one data processor, a room status control based on the motion score; and adjusting, by at least one data processor, a room light level or a room temperature based on the room status control.
14. A system determining motion in a volume using a lighting based sensor, the system comprising: at least one data processor; memory storing instructions, which when executed by at least one data processor, result in operations comprising: determining, a status of a light with which a motion sensor is associated; receiving motion measurements from the motion sensor; determining, based on the motion measurements, a motion score, wherein determining the motion score further comprises: determining a motion signal representation of the motion measurements; and calculating the motion score based on at least one of a number of transitions in the motion signal representation, a number of smoothed reversals in the motion signal representation, and a slew rate of the motion signal representation, wherein calculating the motion score comprises: comparing a data point of the motion signal representation to a most-extreme value variable; replacing the most-extreme valuable variable with the data point if the data point exceeds the most-extreme value variable; identifying a next data point below the most-extreme value variable as one of the smoothed reversals in the motion signal representation; and averaging corresponding voltages of recent smoothed reversals to determine the motion score; adjusting a room status control based on the motion score; and adjusting a room light level or a room temperature based on the room status control.
15. The system of claim 14, wherein averaging comprises an exponentially weighted moving average.
16. The system of claim 15, wherein determining the motion score further comprises generating a smoothed motion signal representation by multiplying the motion signal representation by a smoothing factor.
17. The system of claim 16, wherein determining the motion score further comprises averaging absolute differences between each sample.
18. The system of claim 14, wherein determining the motion signal representation comprises a time-smoother variance of the motion measurements.
19. The system of claim 14, wherein the motion type comprises a major motion, a minor motion, or no motion.
20. The system of claim 14, wherein the operations further comprise transmitting the motion score from the light to a remote location.
21. The system of claim 20, wherein the remote location comprises an HVAC system.
22. The system of claim 14, wherein the room status control comprises a light level or a temperature setting.
23. The system of claim 14, wherein calculating the motion score based on a number of transitions in the motion signal representation comprises: picketing a subset of samples of the motion signal representation over a constant interval; determining a delta-voltage between each sample of the subset of samples; and comparing the delta-voltage to a predetermined threshold, wherein the motion score is based on a number of delta-voltages exceeding the predetermined threshold.
24. A system determining motion in a volume using a lighting based sensor, the system comprising: at least one data processor; memory storing instructions, which when executed by at least one data processor, result in operations comprising: determining a status of a light with which a motion sensor is associated; receiving motion measurements from the motion sensor; determining, based on the motion measurements, a motion score, wherein determining the motion score further comprises: determining a motion signal representation comprising a plurality of frequencies; removing a bias from the motion signal representation; generating a guard band around a midline of the motion signal representation; and determining a number of zero crossings from the motion signal representation, wherein a zero crossing occurs when the signal exceeds the guard band and the motion score comprises the number of zero crossings; adjusting a room status control based on the motion score; and adjusting a room light level or a room temperature based on the room status control.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(21) Light-based sensors can come in a variety of types. In certain examples, data from those light based sensors can be transmitted to a server to coordinate actions. For example, temperature sensors in light bulbs can be used to provide high resolution ambient temperature measurements of a volume, where a server can be used to coordinate heating, ventilation, and air conditioning (HVAC) systems accordingly. As another example, ambient light and/or motion can be measured at light bulbs, where light bulbs can individually adjust their level based on ambient light and/or motion measured at that light bulb, or coordinated light bulb adjustment can be performed through communication among light bulbs or with a server. The following paragraphs describe an example temperature sensing implementation.
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(23) A luminary (e.g., a lighting fixture, light bulb, lamp, or light module that provides illumination) is typically a most common electronic device in a building. Systems and methods as described herein can, in some embodiments, take advantage of the existing power wiring that already exists in most environments for lighting for powering temperature sensors positioned within, on, or next to a lighting device. Having ready sources of power for the lighting devices that are already distributed in environments enables operation of these distributed temperature sensors. Wireless, or wired communications using existing infrastructure (e.g., transmitting signals via power lines connected to the lighting device) enables communications of measured temperatures from the lighting device to another device (e.g., a server, a thermostat, other lighting devices) that have the capability to adjust HVAC or other environment control settings.
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(25) Following is a discussion of one example of such preprocessing. While installing temperature sensors in, on, or near lighting devices as described above accounts for the power and communications issues for distributed temperature sensing, it does not account for an added complication introduced by placing temperature sensors near light sources. Typically, light sources, like light source 104, emit heat. This is indicated by the arrow from light source 104 to temperature sensor 106. This light source 104 heat interferes with the measurement of ambient temperature of the volume by the temperature sensor 106. Thus, in one embodiment, the data processor 114 may adjust temperature data measured by the temperature sensor 106 based on whether the light source 104 is on or off. In other examples, more complex adjustments to temperature data may be made by the data processor 114, such as based on an amount of time that the light source 104 has been on or off or an output level (e.g., 50%, 90%, 100%) of the light source 104, as described further herein.
(26) In one embodiment, the temperature sensing light bulb 102 seeks to measure temperature at a particular height (e.g., an average height of a person standing or sitting) in the volume. Because heat tends to rise, the ambient temperature near the light bulb 102 may be different than the temperature at a desired measurement height. The data processor may further preprocess the data to account for the temperature varying by height, such as by adjusting a temperature sensor 106 measurement by a particular amount or an adjustment factor, such as a factor informed by a calibration operation (e.g., manual measurement of a temperature at the desired measurement height compared to the ambient temperature nearer to the light bulb near a ceiling).
(27) Preprocessing of temperature data by the data processor 114 may be based on other inputs as well, including heat put off by other devices in the light bulb 102 (e.g., transmitter 108, data processor 114, memory 116). Such adjustments to the temperature data may be based on an activity level of those devices, such as current processing load on the data processor 114 or the current throughput of data by transmitter 108, as those devices may produce more heat when working harder. In certain embodiments, preprocessing, as described in
(28) In addition to sensing temperature, light bulb 102 can also include a motion sensor 118 to detect motion within the volume. Similar to temperature sensor 106, motion sensor 118 takes motion measurements, and in the example of
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(30) In addition to commanding the LED light 206, the LED control 210 also provides data to a light status determination module 212 for ascertaining a current state of the LED light 206. The status of the LED light 206 is useful for adjusting the temperature data acquired by the temperature sensor 204. As noted before, the light source 206 outputs heat that can influence the temperature sensed by the temperature sensor 204. But that influence is not the same at all times. For example, the light source's influence is negligible when the light source 206 has been off long enough to reach a steady state heat output compared to when the light source 206 has been on for a significant amount of time. The heat output of the light source 206 further varies during a period shortly after the light source 206 is turned on, turned off, or its power level is adjusted.
(31) In one embodiment of the disclosure, the data processor 205 adjusts a temperature level output by the temperature sensor 204 according to a correction factor 214 stored in a correction factor memory 216. The correction factor memory 216 in one embodiment is a read only memory, preloaded with correction factors, while in another example, the memory 216 is a flash-type memory, where correction factors 214 can be adjusted, such as based on calibration operations. In the embodiment of
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CF=(1−0.68).sup.t Eq. 1
where t is a time ranging from 0 to 1 seconds.
(34) A second zone (2) also spans about 1.0 s, from t=1 s to t=2 s. During the second zone time period, the correction factor still has a decay but with a much shallower slope. That slope may be a near linear fit for most practical purposes, although in some embodiments a curve fit is used. In one example, during this time period, the data processor multiples the measured temperature by a correction factor of:
CF=−0.03t+0.38 Eq. 2
where t is a time ranging from 1 to 2 seconds. A third zone (3) ranges from t=2 s until the light source is turned off and represents a steady state time period where the heat level from the power source that is experienced at the temperature sensor does not change. During this time period, the correction factor in the example of
CF=0.75(t−toff)+0.32 Eq. 3
where t.sub.off indicates a time that the light source was turned off. In the example of
(35) In certain examples, the correction factors described in
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(37) As noted above, a number of additional factors could be considered by a server or light sensor processors in determining estimated ambient temperatures. In one example, correction factors for each of a plurality of light source status zones are bulb type specific. Temperature estimates could further be adjusted based on factors such as whether the associated light bulb is within a lampshade, an open fixture, an enclosed fixture, or a recessed fixture (e.g., a recessed can fixture will typically measure ambient temperatures higher than an open fixture because more heat from the light source will be retained within the fixture). Corrections to measured temperatures could further be based on ambient light detected in a volume being considered. Sunlight into a room can result in it feeling 3-5 degrees warmer than the actual ambient temperature to occupants. Thus, if ambient light is measured to be high, the estimated temperature or the control to the thermostat can be adjusted accordingly. In another example, an online accessible weather report is accessed to determine a sunlight level in a room. Fans running in a volume can also affect temperature measured by a sensor, with adjustments being made based on detection of such a fan's operation (e.g., via a sensed sound level, sensed air movement, or via an indicated control value for the fan).
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(40) As described above with reference to
(41) In another example, the server 902 can provide ambient light measurement data to adjust lighting in rooms, such as sensor containing light bulbs. In the example of
(42) This application uses examples to illustrate the invention. The patentable scope of the invention includes other examples. For example, to enable continued temperature measurement when a light source is off (i.e., typically a light bulb draws no power when off due to an open circuit), a system can be configured to maintain a closed circuit, even when the light source is off, so that temperature sensor operations can still be maintained, despite the light source being off (e.g., at night).
(43) As another example, in a volume having multiple light based temperature sensors, a server or light-based data processors can compare temperature measurements among the sensors in the volume to determine whether any are outliers. Such sensors giving out of family measurements can be voted out or otherwise ignored when controlling the volume environment.
(44) In another example, a distance sensor can be incorporated into a luminary to determine a distance to the floor and an area (e.g., 4-8 feet off the floor) where temperature control is most desirable). Temperature measurements at the luminary can be adjusted based on a distance from the luminary to the floor or region of desired control.
(45) In one example, a number of correction factor profiles for time period zones (e.g., zones (1)-(4) of
(46) As another example, in addition to providing light-based sensing of ambient light and temperature, lights can be configured to detect motion, where environment characteristics can be adjusted based on that detected motion. For example, lights can be turned on or have their levels changed when motion, or a particular type of motion, is detected in a room. Temperature settings can similarly be changed.
(47) Using distributed (e.g., light bulb-based) sensors, motion can be detected using a variety of methods as further described herein. Such discrimination may be dependent upon how clean the electrical environment is surrounding the sensors. For example, noise may impact distinguishing motion (e.g., major motion, minor motion) from quiescence.
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(49) One example motion detecting algorithm is a transition counting algorithm. Using a transition counting algorithm, motion is detected based on detecting a rise in a signal frequency. This transition counting algorithm is based on the Doppler frequency being proportional to velocity. The frequency is gauged by the rate of reversals in the direction of the signal. Motion for a given point is calculated using data from a point to the right of the given point such that the actual response lags the resulting algorithm plot. The transition counting algorithm evaluates the strength of motion at any given time by constructing a picket fence of samples (e.g., 20 samples) selected at constant intervals (e.g., 10 sample intervals) from a reference time. The delta-voltage from one picket to the next is evaluated. The delta-voltage is compares to a threshold voltage in order to determine if there has been a significant movement detected. For example, if the delta-voltage exceeds the threshold voltage, then a significant movement is detected. A motion score can be determined based on the number of direction reversals among the significant movements counted. In one example,
(50) Smoothed reversal counts is an example motion detecting algorithm used to generate a motion signal representation. Using a smoothed reversal counts algorithm, the signal is evaluated for up and down indications and a most-extreme value. If the signal data point exceeds a most-extreme value, that data point value updates the most-extreme value variable. The next data point value that is below this new most-extreme value (e.g., slack) reverses the direction indicator and updates the variable. A motion score is determined based on the count of recent reversals. In one example, the motion score can be determined by adding or averaging the recent per-sample values (e.g., reversal=0, non-reversal=1). Such an average, in one example, is a weighted moving average (EMA). The weighted moving average can be applied more than once (e.g., twice) so as to provide for extra smoothness in the output signal. Using a slack threshold allows for tuning ability and avoids responding to noise, along with adjusting the sensitivity.
(51) Another example algorithm for motion detection includes a smooth reversal count that is adjusted for relative signal strength. In some instances, the frequency of test spliced motion signal drops as a result of a subject walking past the motion sensor relative to what it is in approach or departure, despite the signal strength being higher. A reversal count of the signal can be multiplied by a variable that divided signal strength to the smoothed prior signal strength.
(52) A slew rate algorithm is yet another example motion detecting algorithm that can generate a motion signal representation. Similar to the smooth reversal count algorithm, the signal is multiplied by a frequency proxy based on relative amplitude. The derivative of the signal rises with both amplitude and frequency. Using a moving average of absolute differences from one sample to the next provides for multiplying the amplitude by the frequency.
(53) Another example motion detection algorithm is the smoothed standard deviation algorithm that can generate a motion signal representation. Using this algorithm, a time-smoothed variance of the signal is measured.
(54) A smoothed zero crossing algorithm is another example algorithm that can generate a motion signal representation. Using the smoothed zero crossing algorithm, the frequency of the signal is determined. A DC bias is subtracted out from the signal. A count of the times the signal crosses zero within a time period is used to measure an overall frequency. In the absence of motion, the noise-only signal crosses zero frequently. Such frequency crossings can cause false elevated readings. A guard band is created around the midline of the signal so that a zero crossing is counted only when the swing exceeds a nominal noise level.
(55) While the disclosure has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the embodiments. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.