Sensor light having occupancy detection function enhanced by heterogeneous sensors

Abstract

A sensor light having an occupancy detection function enhanced by heterogeneous sensors may be disclosed. The sensor light turned on by a sensor for detecting the presence of a person may comprise: a PIR detection sensor for detecting occupancy by detecting a heat change amount; an image sensor for detecting the presence of a person on the basis of an image of an area in which the sensor light is installed; a control unit for receiving an occupancy signal generated from at least one of the PIR detection sensor and the image sensor, and generating a control signal for turning a lamp on or off; and the lamp turned on or off on the basis of the control signal.

Description

Sensor lights with enhanced presence detection capabilities based on heterogeneous sensors

[0001] The present invention relates to a sensor light with improved occupancy detection function, and to a sensor light that operates more accurately and efficiently based on heterogeneous sensors.

[0002] In order to prevent excessive power consumption, sensor lights are installed in stairwells, entrances, parking lots, garages, warehouses, etc. of apartments and buildings. When a moving object such as a person or vehicle enters a certain range around the installation location, the lights turn on for a certain amount of time and turn off in all other situations.

[0003] A conventional sensor light is illustrated in Figure 1. To reduce power consumption, control methods have been developed for existing sensor lights that work in conjunction with human body detection sensors. For example, PIR (Pyroelectric Infrared Ray) sensors, commonly used as occupancy / vacancy sensors, detect the difference between the heat emitted by a moving human body and the background space to determine whether a person is present or absent.

[0004] Referring to Fig. 1, the conventional sensor light (10) using the most widely used PIR detection sensor (11) detects a moving object through the PIR detection sensor (11) and is implemented in a way that the light source turns on according to the detection signal. However, since this PIR detection sensor is based on a method of detecting heat change, it cannot detect presence, that is, whether a human body is located in the vicinity, when the human body moves slowly, has little movement, or is stationary. In addition, there is a problem that a moving object emitting a certain amount of infrared ray is not continuously detected if it does not move from a fixed location after being initially detected. Therefore, in order to turn the light on again after an unwanted turning off, a person must repeatedly take additional actions, such as moving the body greatly or swinging the arms, which is inconvenient.

[0005] Rather than adopting only a single sensor such as a PIR detection sensor, a sensor light can be provided that improves the occupancy sensing function by mounting different types of sensors, thereby enabling stable continuous lighting when a person is present under the light.

[0006] Rather than adopting only a single sensor such as a PIR detection sensor, a sensor light can be provided that improves the occupancy sensing function by mounting different types of sensors, thereby enabling stable continuous lighting when a person is present under the light.

[0007] A sensor light can be provided that improves the occupancy sensing function by mounting different types of sensors, thereby enabling stable continuous lighting when a person is present under the light.

[0008] Figure 1 is a drawing for explaining a sensor light and its use according to conventional technology.

[0009] FIG. 2 is a drawing for explaining an electronic device and an existing sensor according to an embodiment of the present invention.

[0010] FIG. 3 is a drawing for explaining the configuration of an electronic device according to an embodiment of the present invention.

[0011] Figure 4 is a drawing for explaining the signal form detected by a PIR detection sensor such as an existing sensor.

[0012] FIG. 5 is a drawing for explaining the output signal form of an electronic device according to an embodiment of the present invention.

[0013] FIG. 6 is a drawing for explaining the waveform of power applied to a pseudo signal generator according to an embodiment of the present invention.

[0014] FIG. 7 is a drawing for explaining the installation form of an electronic device according to one embodiment of the present invention.

[0015] FIG. 8 is a drawing for explaining the installation form of an electronic device according to another embodiment of the present invention.

[0016] Figure 9 shows a block diagram of a sensor, etc., according to one embodiment.

[0017] FIG. 10a illustrates a flowchart of a method for determining whether an image sensor unit is present, according to one embodiment.

[0018] FIG. 10b illustrates a flowchart of a method for updating a background image by an image sensor unit, according to one embodiment.

[0019] FIG. 11 illustrates image frames acquired by an image sensor unit according to one embodiment.

[0020] Figure 12 shows images showing areas where sensors are installed, according to one embodiment.

[0021] Figure 13 shows the point in time at which the image sensor unit starts operating, according to one embodiment.

[0022] A sensor light that is turned on by a sensor that detects the presence of a person includes a PIR detection sensor unit for detecting presence by detecting a heat change, an image sensor unit for detecting presence based on an image of an area in which the sensor light is installed, and a light that is turned on when presence is detected by at least one of the PIR detection sensor unit and the image sensor unit, and the light that is in an off state is turned on when presence is detected by the PIR detection sensor unit, but may not be turned off when presence is detected by the image sensor unit even after a preset period has passed from the time when presence was last detected by the PIR detection sensor unit.

[0023] The above image sensor unit is in a sleep state when the light is turned off, and when presence is detected by the PIR detection sensor and the light is turned on, the light is changed from a sleep state to a wake-up state before the light is turned off according to the cycle from turning on to turning off, thereby performing presence detection.

[0024] The above image sensor unit determines presence if a person is present in the image, and whether a person is present in the image can be determined based on at least one of a CNN (Convolutional Neural Network) model, an SVM (Support Vector Machine) algorithm, and a YOLO (You Only Look Once) algorithm.

[0025] The above sensor further includes a memory for storing an image of the area in which there is no person as a background image, and the image sensor unit can determine presence if a first delta value indicating a difference between the currently acquired image and the background image is greater than a first reference value.

[0026] After the image sensor unit determines that the room is occupied (while the light is kept on), if the second delta value of the images acquired by the image sensor unit is less than the second reference value, one of the images is updated to the background image, and the second delta value may be a value indicating the amount of change in the images.

[0027] Below, several embodiments will be described clearly and in detail with reference to the attached drawings so that those skilled in the art (hereinafter, “ordinary technicians”) can easily practice the present invention.

[0028] Hereinafter, the term "sensor light" may refer to a light source that turns on when a sensor detects a human body, a person, or any type of object. In this specification, the term "sensor light" is mainly described with reference to a sensor light that employs a PIR detection sensor as an example, but is not limited thereto. The term "sensor light" in this specification should be interpreted as a sensor light that employs any sensor capable of detecting a human body, a person, or any type of object.

[0029] Hereinafter, ‘existing sensor lights’ may refer to sensor lights already installed and used in a designated location.

[0030] Hereinafter, 'Occupancy' may refer to a state in which a person is present in an area where a sensor light is installed (e.g., entrance, garage, elevator, hallway, bathroom, parking lot, restroom, warehouse, factory, etc.).

[0031] FIG. 2 is a drawing for explaining an electronic device and an existing sensor according to an embodiment of the present invention.

[0032] The electronic device (20) is a device to assist the operation of the sensor light (10), and is intended to assist the stable operation of the sensor light (10) by complementing the shortcomings of the human body sensing function or the occupancy sensing function of the sensor light (10). The electronic device (20) can solve the problems of the PIR sensor of the existing sensor light (10) that employs the PIR detection sensor simply by being installed around the sensor light without replacing the sensor light. That is, since the existing PIR sensor is a method of detecting the amount of heat change, the problem of not being able to properly detect the presence of the human body when moving at low speed or when stopped, resulting in the light being turned off even when a person is present, can be easily solved by placing the electronic device (20) around the sensor light (10).

[0033] Referring to FIG. 2, an existing sensor light (10) that detects heat generated from a human body with a PIR detection sensor (11), which is a human body detection sensor, and turns on when a human body is detected exists in a predetermined space. An electronic device (20) can be placed within the detection range of the sensor light (10). The detection range refers to the range in which the sensor light (10) can detect a human body (or, including other types of objects) to turn on the light source. The placement location of the electronic device (20) can be anywhere within the detection range of the PIR detection sensor (11) around the existing sensor light (10).

[0034] An electronic device (20) placed within the detection range of a PIR detection sensor (11) can perform its own human body detection independently from the PIR detection sensor (11) and continuously generate a pseudo signal while a human body is detected, thereby outputting a fake human body signal (pseudo signal) to the PIR detection sensor (11). Accordingly, since the PIR detection sensor of the existing sensor light (10) continuously detects the pseudo signal, the sensor light (10) can be stably lit even if there is no significant movement of the human body while the human body remains within the detection range.

[0035] FIG. 3 is a drawing for explaining the configuration of an electronic device according to an embodiment of the present invention.

[0036] An electronic device (20) may include a sensor unit (23) for detecting a human body, a control unit (22) for receiving a human body detection signal generated from the sensor unit (23) and controlling the generation of a pseudo signal, a pseudo signal generator (21) for generating a pseudo signal according to human body detection under the control of the control unit (22), and a power supply unit (24) for supplying operating power to the sensor unit (23), the control unit (22), and the pseudo signal generator (21).

[0037] The pseudo signal generated by the pseudo signal generator (21) can be detected by the PIR detection sensor (11) of the sensor light (10), and the PIR detection sensor (11) of the sensor light (10) that detects this signal can recognize the pseudo signal as a human body detection signal.

[0038] The above sensor unit (23) performs human body detection within a predetermined range, and can generate a human body detection signal when a human body is detected.

[0039] The above sensor unit (23) can be configured with any type of human body detection sensor except for a PIR sensor that detects heat change. For example, the sensor unit (23) can be configured with various types of human body detection sensors such as an ultrasonic sensor that detects ultrasonic energy caused by the movement of the human body, an infrared sensor that detects infrared energy, a radar sensor that detects the phase change of radio waves through a patch antenna to detect the human body, a biometric detection sensor that can recognize a person through breathing, etc., a camera-based image sensor that can recognize a person, etc., but is not limited thereto. The sensor unit (23) can be configured with any type of sensor that can detect a human body even when there is no movement of the human body, unlike the PIR detection sensor (11) of the sensor (10) that detects heat change.

[0040] The control unit (22) can receive a human body detection signal generated from the sensor unit (23) and operate the pseudo signal generator (21). The control unit (22)'s operation control of the pseudo signal generator (21) can continue while the human body detection state of the sensor unit (23) is maintained. According to one embodiment, the control unit (22) can control the pseudo signal generator (21) so that the pseudo signal is continuously output while the human body detection by the sensor unit (23) continues. Alternatively, the control unit (22) can control the pseudo signal generator (21) so that the pseudo signal is intermittently or one-time output only to the extent that the sensor light (10) is kept on even when the human body detection by the sensor unit (23) continues.

[0041] The above pseudo signal generator (21) can independently generate and output a pseudo signal according to human body detection under the control of the control unit (22).

[0042] FIG. 4 is a drawing for explaining the signal form detected by a PIR detection sensor such as an existing sensor, according to one embodiment.

[0043] The PIR detection sensor (11) of the existing sensor light (10) generates a detection signal as shown in (a) of Fig. 4 when a person enters the detection range.

[0044] The PIR detection sensor (11) detects infrared rays (heat) emitted from the human body. That is, when a temperature change occurs due to external conditions (human body) within the surveillance area determined by the Fresnel lens, the pyroelectric element converts this temperature change into an electrical signal, and when it exceeds a certain standard (signal size / number of pulses generated), the human body detection situation can be output to the outside.

[0045] Additionally, if a person within the detection range does not move, a detection signal as shown in (b) of Fig. 4 can be generated. That is, since no thermal change occurs when a person does not move, a detection signal is no longer generated after a certain period of time.

[0046] Therefore, the pseudo signal generator (21) of the electronic device (20) must generate heat exceeding a reference value periodically or non-periodically as shown in FIG. 5 so that the PIR detection sensor (11) of the existing sensor light (10) continuously outputs a detection signal.

[0047] For this purpose, the pseudo signal generator (21) can generate a heat signal as a pseudo signal.

[0048] For example, the pseudo-signal generator (21) may be configured with at least one infrared LED that emits light periodically or non-periodically. At this time, the emission cycle of the infrared LED should be shorter than the cycle from lighting on to turning off according to the human body detection of the PIR detection sensor (11) (the time for which the light is maintained on after the human body is detected once by the sensor light (10). In this way, the sensor light (10) can be continuously lit by the pseudo-signal before it is turned on and then turned off. The infrared LED can generate a certain amount of heat along with light to generate a pseudo-signal tailored to the PIR detection sensor (11).

[0049] As another example, the pseudo signal generator (21) may be composed of at least one resistive heating element that periodically generates heat. At this time, the heating cycle of the resistive heating element should be shorter than the cycle from lighting on to turning off according to the human body detection of the PIR detection sensor (11) (the time for which the light is maintained on after the human body is detected only once by the sensor light (10). In this way, the sensor light (10) can be continuously lit by the pseudo signal before it is turned off after being lit. The resistive heating element can generate a certain amount of heat according to the applied power to generate a pseudo signal tailored to the PIR detection sensor (11).

[0050] More specifically, in the pseudo signal generator (21) of the other example described above, the resistance heating element is composed of two, and power can be applied as shown in Fig. 6 so that they are crossed over each other and heat up.

[0051] These resistance heating elements can enable the pseudo signal generator (21) to be driven at low power by adjusting the resistance value.

[0052] In particular, power efficiency can be further improved by applying power to each resistance heating element in the form of a PWM waveform. Here, the resistance heating element constituting the pseudo signal generator (21) does not necessarily have to be two, and even if it is configured as a single element, the configuration is possible as long as the heating cycle is shorter than the cycle from lighting to turning off according to human body detection by the PIR detection sensor (11).

[0053] FIG. 7 is a drawing for explaining the installation form of an electronic device according to one embodiment of the present invention.

[0054] In Fig. 7, the existing sensor light (10) can detect human movement through the PIR detection sensor (11) and turn on when a human body is detected. The electronic device (20) is installed within the detection range of the PIR detection sensor (11) around the existing sensor light (10) so that the PIR detection sensor (11) can detect a pseudo signal. The power supply (24) of the electronic device (20) can be configured with an existing indoor commercial power source or a battery.

[0055] In this arrangement, the electronic device (20) detects a human body on its own and generates a pseudo-signal accordingly. This pseudo-signal will be generated while the human body detection state of the sensor unit (23) within the electronic device (20) is maintained.

[0056] Accordingly, the above PIR detection sensor (11) maintains the lighting state dependent on the pseudo signal generated from the electronic device (20) regardless of human body movement.

[0057] FIG. 8 is a drawing for explaining the installation form of an electronic device according to another embodiment of the present invention.

[0058] If the power supply unit (24) of the electronic device (20) is configured with a battery, the overall size of the device can be manufactured to be extremely small. In this embodiment, the entire configuration of the pseudo signal generator (21), control unit (22), and sensor unit (23), including the power supply unit (24), can be built into a single housing (30).

[0059] In addition, the housing (30) can be attached to an existing sensor light (10) using a fastening means (25). When attaching, it is preferable that the pseudo signal generator (21) be attached so that it is close to the PIR detection sensor (11) of the sensor light (10) with a minimum gap. In such a structure, even if the pseudo signal generator (21) generates a heat signal of relatively small intensity, the PIR detection sensor (11) at a close distance will be able to sufficiently detect the heat signal. This can ultimately further increase the power efficiency of the electronic device (20).

[0060] Here, the fastening means may be any method that can fasten the housing (30) to the PIR detection sensor (11) or the sensor light (10). For example, the fastening means may be configured as an adhesive so that the PIR detection sensor (11) or the sensor light (10) can be firmly adhered to the housing (30). In addition, the fastening means may be configured as a hooking protrusion that can be hooked to a groove of the housing (30) so that the PIR detection sensor (11) or the sensor light (10) can be firmly hooked to the housing (30). In addition, the fastening means may be configured as a threaded protrusion that can be fitted into a screw groove of the housing (30) so that the PIR detection sensor (11) or the sensor light (10) can be firmly fitted to the housing (30).

[0061] In addition, the pseudo signal generator (21) may be built into a separate tube or enclosure so that the pseudo signal generator (21) is brought into close proximity to the PIR detection sensor (11) of the sensor light (10) with a minimum distance. At this time, it is important that the material of the tube or enclosure is made of a material through which the pseudo signal can pass so that the pseudo signal generated from the pseudo signal generator (21) inside can easily reach the PIR detection sensor (11) at a short distance. Through this configuration, the distance between the pseudo signal generator (21) and the PIR detection sensor (11) can be reduced, thereby increasing the energy efficiency of the pseudo signal generator (21) and enhancing the detection performance for the pseudo signal, thereby enabling more reliable device operation.

[0062] While minimizing the power consumption generated by the operation of the electronic device (20), the sensor light (10) should not be turned off while a person is under the light, causing inconvenience. As power consumption is minimized, if the electronic device (20) is configured with a battery as its power source, the battery's lifespan can be extended and the number of recharges can be reduced. Hereinafter, embodiments for reducing the power consumption of the electronic device (20) are disclosed.

[0063] According to one embodiment, the electronic device (20) may be configured to operate only when the sensor light (10) is turned on or when the sensor light (10) detects a human body. The electronic device (20) may conditionally operate only when the sensor light (10) is turned on. According to one embodiment, the sensor unit (23) of the electronic device (20) may operate when the sensor light (10) is turned on or when the sensor light (10) detects a human body. That is, the sensor unit (23) may not always detect a human body, but may operate only under certain conditions.

[0064] So far, we've described electronic devices installed around sensor lights. Below, we'll describe sensor lights based on multiple sensors. The sensor lights described below can enhance occupancy sensing capabilities solely through their own operation, without the need for any additional auxiliary devices.

[0065] Figure 9 shows a block diagram of a sensor, etc., according to one embodiment.

[0066] Referring to FIG. 9, the sensor light (SL) may include a PIR detection sensor unit (PS), an image sensor unit (IS), and a light (L). The sensor light (SL) may be installed in a predetermined area and may determine whether a person is present based on the PIR detection sensor unit (PS) and / or the image sensor unit (IS) and may turn on the light (L) according to the determination result. Therefore, since the light (L) of the sensor light (SL) is normally turned off, power is saved, and since the light is turned on by the human presence detection function of heterogeneous sensors (PIR detection sensor unit (PS) and image sensor unit (IS)) mounted on the sensor light (SL), inconvenience due to the functional limitations of the conventional sensor light may be minimized.

[0067] The light (L) can be turned on when presence is detected by at least one of the PIR detection sensor unit (PS) and the image sensor unit (IS). For example, changing from an off state to an on state can be performed by an occupancy detection signal of the PIR detection sensor unit (PS), and maintaining the lighting of the turned-on light (L) or turning it off can be determined by an occupancy detection signal of the PIR detection sensor unit (PS) or the image sensor unit (IS). The light (L) can be turned on by occupancy detection, maintained on for a preset period, and turned off when no occupancy is detected again. For example, the light (L) in an off state can be turned on when presence is detected by the PIR detection sensor unit (PS), but can be maintained on without being turned off when presence is detected by the image sensor unit (IS) even after a preset period has passed since the last time occupancy was detected by the PIR detection sensor unit (PS). According to one embodiment, the cycle (P1) of the light (L) turned on by the PIR detection sensor unit (PS) and the cycle (P2) of the light (L) turned on (or kept on) by the image sensor unit (IS) may be the same or different.

[0068] The PIR detection sensor unit (PS) and the image sensor unit (IS) may each be equipped with a processor, or the PIR detection sensor unit (PS) and the image sensor unit (IS) may share a processor. The processor may perform calculations based on sensor data acquired by the PIR detection sensor unit (PS) or the image sensor unit (IS). The PIR detection sensor unit (PS) and the image sensor unit (IS) may be interpreted as including not only the sensor itself but also an electrical circuit (e.g., a processor) for generating meaningful information based on the sensor data.

[0069] The PIR detection sensor unit (PS) can detect the presence of a person by detecting infrared rays and human movement. The PIR detection sensor unit (PS) has been described above with reference to FIGS. 1 to 8, so a detailed description thereof will be omitted. The PIR detection sensor unit (PS) can efficiently detect the presence of a person when a person enters (or enters) the installation area of ​​the sensor light (SL) or when the person's movement is large. If the PIR detection sensor unit (PS) determines that a person is present, the light (L) can be turned on.

[0070] The image sensor unit (IS) can detect whether a person is present based on image information. The image sensor unit (IS) may include any type of sensor capable of obtaining image information of an installation area. The image sensor unit (IS) may include a camera, a charge-coupled device (CCD) sensor, a complementary metal-oxide-semiconductor (CMOS) sensor, a backside-illuminated (BSI) sensor, etc. According to an embodiment, the image sensor unit (IS) may be a complementary metal-oxide-semiconductor image sensor (CIS sensor). The presence detection of the image sensor unit (IS) may be performed for each frame or at regular time intervals. For example, the period in which the image sensor unit (IS) performs presence detection may be determined to be shorter than the period (P2).

[0071] In one embodiment, the image sensor unit (IS) can use an algorithm, such as an artificial intelligence model, to determine and detect whether a person is present in the currently acquired image. The algorithm may include, but is not limited to, a Support Vector Machine (SVM) algorithm, a You Only Look Once (YOLO) algorithm, a Convolutional Neural Network (CNN) model, and the like. The image sensor unit (IS) can determine an occupancy state if an object corresponding to a person is detected in the current image frame.

[0072] According to another embodiment, the image sensor unit (IS) can compare the current image (current frame) acquired in real time with a background image, and determine occupancy if the difference between the background image and the current image is greater than a reference value. The background image may be an image showing the appearance of a moving object before entering the installation area of ​​the sensor light (SL) (for example, B in FIG. 12). The background image may be stored in the memory of the sensor light (SL). If there is a difference between the current frame and the background image, it may be determined that a person is present (occupancy) in the space where the sensor light (SL) is (for example, P in FIG. 12). The comparison between images may be performed based on frame differencing, or any other known method may be used. The greater the difference between the current frame and the background image, the larger the first delta (Delta1) value may be. The first delta represents the degree of difference between the two images.

[0073] [Mathematical Formula 1]

[0074] First delta = |F c - F bg | (F c is the current frame , F bg : background image)

[0075] Referring to Fig. 10a, the current frame and the background image are compared (S1010), and if the first delta, which is the difference between the current frame and the background image, is greater than or equal to the first reference value (S1020, Yes), the current state can be determined to be occupied (S1030). If the first delta is less than the first reference value (No), the current state can be determined not to be occupied (S1040).

[0076] In one embodiment, the background image may be updated, as the environment surrounding the sensor light (SL) installation area may change. If the background image is not updated, the image sensor unit (IS) may determine that a person is present even when no person is present.

[0077] For example, a sensor light (SL) may be installed in the entrance hall, and the background image may be stored as an image of the entrance hall without an umbrella. If a person enters the hallway, puts down the umbrella, and then leaves, the currently acquired image frame will contain an umbrella that was not present before, resulting in a difference in the background image. This may cause the image sensor unit (IS) to determine that the room is occupied and keep the light (L) on. Therefore, in such cases, the background image must be updated to an image of the space with the umbrella present.

[0078] For example, a sensor light (SL) may be installed in an empty garage and an image of a vehicle-less garage may be stored as a background image (B in Fig. 12). If a person enters and exits a vehicle in the garage, the currently acquired image frame may contain a vehicle that was not present before (C in Fig. 12), resulting in a difference from the background image (B in Fig. 12). This may cause the image sensor unit (IS) to determine that the garage is occupied and cause the light (L) to remain on. Therefore, the background image must be updated to a spatial image of a vehicle-occupied garage (C in Fig. 12).

[0079] Referring to FIGS. 10B and 11, a method for an image sensor unit (IS) to determine whether a person is present and update a background image will be described. Steps S1010, S1020, S1030, and S1040 in the flowchart of FIG. 10B are the same as those described above with reference to FIG. 10A. If the image sensor unit (IS) determines an occupancy state by comparing the current frame (CF1) with a background image in step S1030, the image sensor unit (IS) can determine a second delta (Delta2) for the image frames (AFS) in step S1050. The second delta is an index indicating an amount of image change between a plurality of image frames (AFS). If there is little change between the image frames (AFS) for a predetermined time interval, it can be determined that there is only a background without a foreground, and one of the image frames (AFS) (CF2) can be stored as a new background image. For example, if a vehicle is parked in a garage and a person enters a house, the garage image acquired by the image sensor unit (IS) will be in a state of complete absence of movement, so there will be little change and the second delta value will be close to 0. In this case, the background image can be updated from an empty garage image (B of FIG. 12) to an occupied garage image (C of FIG. 12). Referring back to FIG. 10, if the second delta is less than the second reference value (Yes) in step S1050, the current image is determined to be in a static state with little change, and thus it is determined that there is no occupancy (step S1070), and at the same time, one of the frames (CF2) can be updated with a new background image (step S1060). Since there is no occupancy, the occupancy detection function of the image sensor unit (IS) is terminated.

[0080] In one embodiment, the second delta may be determined using a method for determining the first delta. If the first delta is a difference between two image frames, the second delta may be determined by accumulating or averaging the first delta between the two image frames over multiple frames. However, the method for determining the second delta may use any known method for representing the amount of image change over multiple frames, and is not limited thereto.

[0081] [Equation 2]

[0082] Second delta = |F2- F1| + |F3- F2| + |F4- F3| + |F n - F n-1 |

[0083] (F n is the nth frame, where n is an integer)

[0084] In the above mathematical formula 2, F n class F n-1 It is not necessary that the frames be consecutive. If the n video frames (AFS) are static images, the second delta will be close to 0.

[0085] If the second delta is greater than or equal to the second reference value in step S1050 (No), presence detection can be continuously performed by comparing the current frame and the background image in step S1010.

[0086] In one embodiment, the image sensor unit (IS) may not be always on, but may be turned on only when necessary to save power. The sensor light (SL) is basically switched from an off state to an on state by the PIR detection sensor unit (PS), and the image sensor unit (IS) may be utilized to supplement the occupancy detection function of the PIR detection sensor unit (PS). Accordingly, the image sensor unit (IS) may only begin operating when the PIR detection sensor unit (PS) determines that occupancy is present.

[0087] According to one embodiment, the image sensor unit (IS) is normally in a sleep state and can perform occupancy detection by changing to a wake-up state after the light (L) is turned on by the PIR detection sensor unit (PS) (for example, before the light is turned off because no human movement is detected (detection by the PIR detection sensor unit (PS)) after the light is last turned on by the PIR detection sensor unit (PS). Referring to FIG. 13, the image sensor unit (IS) in the sleep state can be changed to a wake-up state before the time (t2) at which the light (L) is turned off after a period (T = P1) has elapsed since the time (t1) at which the PIR detection sensor unit (PS) last detected occupancy. The period (T) means the period from the turning on of the light (L) to the turning off of the light, i.e., the time for which the light is turned on when a person is detected only once by the PIR detection sensor unit (PS). Accordingly, since the image sensor unit (IS) operates while the light (L) is on, there are few cases where the image cannot be acquired due to darkness. According to one embodiment, the image sensor unit (IS) in the wake-up state may change back to the sleep state if presence is not detected (for example, steps S1040 and S1070 of FIG. 10b). In the flowcharts of FIGS. 10a and 10b, start may mean a change from the sleep state of the image sensor unit (IS) to the wake-up state, a start of the presence detection operation, a supply of power, etc. In the flowcharts of FIGS. 10a and 10b, end may mean a change from the wake-up state of the image sensor unit (IS) to the sleep state, a termination of the presence detection operation, a cutoff of the power supply, etc.

[0088] In one embodiment, the light (L) may be turned off by gradually or gradually dimming in a dimming manner before being turned off. The user may recognize that the light (L) is about to be turned off by the dimming light (L) and take action, thereby preventing the light (L) from being turned off while the user is present.

[0089] It should be understood that the image sensor described herein may be replaced with any type of sensor capable of detecting human presence, such as an ultrasonic sensor, an infrared sensor, a radar sensor, or a biosignal sensor. Accordingly, the on / off operation of sensors other than the image sensor may also be applied using the method described herein.

[0090] The descriptions are intended to provide exemplary configurations and operations for implementing the present invention. The technical concept of the present invention encompasses not only the embodiments described above, but also implementations that can be achieved by simply modifying or altering the above embodiments. Furthermore, the technical concept of the present invention encompasses implementations that can be easily achieved by modifying or altering the above embodiments in the future.

Claims

1. In a sensor light that is turned on by a sensor that detects the presence of a person, A PIR detection sensor unit for detecting presence by detecting heat change; An image sensor unit for detecting presence based on an image of the area where the above sensor lights are installed; and It includes a light that turns on when presence is detected by at least one of the PIR detection sensor unit and the image sensor unit, A sensor light that is turned on when presence is detected by the PIR detection sensor unit in the off state, but is not turned off when presence is detected by the image sensor unit even after a preset period has passed since the last time presence was detected by the PIR detection sensor unit.

2. In paragraph 1, The above image sensor unit is in a sleep state when the light is turned off, and when presence is detected by the PIR detection sensor and the light is turned on, the sensor light changes from the sleep state to the wake-up state before the light is turned off according to the cycle from turning on to turning off, thereby performing presence detection.

3. In paragraph 1, The above image sensor determines that a person is present in the image, A sensor that determines whether a person exists in the above image based on at least one of a CNN (Convolutional Neural Network) model, an SVM (Support Vector Machine) algorithm, and a YOLO (You Only Look Once) algorithm.

4. In paragraph 1, Further comprising a memory for storing an image of the above area in a state where there is no person as a background image, The above image sensor unit is a sensor that determines presence when the first delta value indicating the difference between the currently acquired image and the background image is greater than the first reference value.

5. In paragraph 4, After the image sensor unit determines that the image is present, if the second delta value of the images acquired by the image sensor unit is less than the second reference value, one of the images is updated to the background image, and the second delta value is a value indicating the amount of change in the images.

Images