Security System and Security Method

Abstract

A heat image acquisition unit (2) photographs a veranda (1) to acquire a heat image. A setting unit (11) sets, in the heat image, an outdoor area (15) that corresponds to the outside of the veranda (1) and an in-veranda area (16) that corresponds to the inside of the veranda (1). A heat source detection unit (9) detects a heat source (14) in the heat image. If in the heat image, the center position of the heat source (14) having the number of pixels and a temperature at the threshold or more move to the in-veranda area (16) from the outdoor area (15), an intrusion determination unit (12) determines that there is an intrusion. A determination result output unit (13) outputs the determination result by intrusion determination unit (12). This may allow a crime prevention system that monitors whether there is an intrusion into the veranda or not, to have a smaller determination device and consume less power.

Description

Technical Field

[0001] The present disclosure relates to a security system and a security method for monitoring the presence or absence of intrusion into a veranda.

Background Art

[0002] According to the statistical data on criminal law offenses of the police department, the intrusion of suspicious persons into residences occurs not only through the front door but also frequently through the veranda. In particular, in the upper floors of apartment buildings, the locking of windows is more likely to be neglected compared to the first floor, and security glass is rarely installed, resulting in weak awareness and countermeasures regarding security. In addition, since the veranda allows intruders to hide easily behind the parapet wall, it is easy for them to take time to break in through the window. Furthermore, since it is easy to move to adjacent residences via the partition installed between residences, the damage may increase once someone intrudes into the veranda. For these reasons, the importance of veranda security has been increasing.

[0003] Since the intrusion of suspicious persons occurs day and night, a security system that can monitor even at night is required. In response, the installation of a surveillance camera that irradiates infrared rays on the veranda can be considered. However, for high-resolution surveillance cameras, an installation method that takes into account the privacy of residents and neighboring residents and strict management of the captured videos are required, and the hurdles in introduction and operation are high.

[0004] In addition, in order to monitor the presence or absence of intrusion into the veranda, a process of detecting people on software is necessary. For example, a security system that 3D models the detected objects each time using a distance sensor and constantly calculates the volume and shape changes has also been disclosed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, since these security systems use complex algorithms and require a high-performance CPU, the size and power consumption of the determination device increase.

[0007] The present disclosure has been made to solve the above-described problems, and an object thereof is to obtain a security system and a security method capable of miniaturizing a determination device and reducing power consumption.

Means for Solving the Problems

[0008] The security system according to the present disclosure includes a thermal image acquisition unit that captures an image of a veranda to acquire a thermal image, a setting unit that sets an outdoor area corresponding to the outside of the veranda and a veranda interior area corresponding to the inside of the veranda in the thermal image, a heat source detection unit that detects a heat source in the thermal image, an intrusion determination unit that determines "intrusion detected" when the center position of the heat source with a pixel count and temperature equal to or higher than a threshold value in the thermal image moves from the outdoor area to the veranda interior area, and a determination result output unit that outputs a determination result by the intrusion determination unit.

Effects of the Invention

[0009] In the present disclosure, a heat source with a pixel count and temperature equal to or higher than a threshold value is detected in a thermal image, and when the center position of the heat source moves from the outdoor area to the veranda interior area, it is determined that "intrusion detected". Since the determination of whether or not there is an intruder is made only based on whether or not the temperature and pixel count of the heat source are equal to or higher than the threshold value, the amount of calculation of the intrusion determination unit can be small. Therefore, in a security system that monitors the presence or absence of intrusion into a veranda, the determination device can be miniaturized and power consumption can be reduced.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0011] A security system and a security method according to an embodiment will be described with reference to the drawings. The same or corresponding components may be denoted by the same reference numerals, and repeated description may be omitted.

[0012] Embodiment 1. FIG. 1 is a diagram showing how the thermal image acquisition unit of the security system according to Embodiment 1 is installed. The thermal image acquisition unit 2 is attached to the ceiling or wall surface of the balcony 1 of each dwelling in an apartment building such as a condominium. Here, the balcony 1 is a part that projects externally from the main house of the dwelling, is surrounded by a waist wall 3 and a wall or partition 4, and is located under an eaves or a soffit. However, it is not limited to this, and a balcony without an eaves may also be used.

[0013] In FIG. 1, one thermal image acquisition unit 2 is attached to one end of the balcony 1. The thermal image acquisition unit 2 is, for example, an infrared array sensor, and takes a thermal image of the balcony 1 to acquire a thermal image. As the infrared array sensor, for example, one in which infrared sensors such as bolometers, thermopiles, and thermal diodes are arranged in a matrix can be used. By using an infrared array sensor, it is possible to take a picture of the balcony 1 even at midnight while taking privacy into consideration. The determination device 5 determines whether an intruder has entered the balcony 1 based on the acquired thermal image. Note that the thermal image acquisition units 2 may be provided at both ends of the balcony 1 of each dwelling to take pictures of the balcony 1 from opposite sides.

[0014] FIG. 2 is a diagram showing the view seen from the thermal image acquisition unit. By perspective drawing, the boundary line between the waist wall 3 of the balcony 1 and the outdoors 6 extends obliquely. Similarly, the boundary line between the ceiling 7 and the outdoors 6 also extends obliquely. A partition 4 is provided between the balconies of adjacent dwellings. The outdoors 6 is surrounded by the end of the waist wall 3, the end of the ceiling 7, and the end of the partition 4. A window 8 is provided between the interior and the balcony 1.

[0015] FIG. 3 is a block diagram showing the security system according to Embodiment 1. The determination device 5 includes a heat source detection unit 9, a storage unit 10, a setting unit 11, and an intrusion determination unit 12. The determination result output unit 13 outputs the determination result by the intrusion determination unit 12.

[0016] The heat source detection unit 9 detects, in the acquired thermal image, a heat source having a number of pixels and a temperature equal to or higher than a preset threshold value as a heat source corresponding to an intruder. The storage unit 10 stores the thermal image in which the heat source is detected by the heat source detection unit 9.

[0017] The temperature threshold is a temperature higher than the specified temperature by a certain amount from the reference temperature. The reference temperature is the temperature of the thermistor or temperature IC built into the infrared camera for measuring the temperature of the infrared sensor, or the temperature of the mechanical shutter built into the infrared camera. The specified temperature is arbitrarily set by the user and input at the time of initial setting. It is preferable to count the number of pixels of the heat source and exclude those that do not meet a predetermined minimum size. This can reduce false detection.

[0018] The setting unit 11 sets an area in the thermal image using software. FIGS. 4 and 5 are diagrams showing thermal images in which the setting unit according to Embodiment 1 has set an area. FIG. 4 shows a state where there is no intruder. Since there is a difference in temperature between the veranda 1 and the inside of the room, the portion of the window 8 is displayed as a different temperature in the thermal image. FIG. 5 shows a state where an intruder has entered. The intruder is displayed as the heat source 14.

[0019] The setting unit 11 sets, in the thermal image, an outdoor area 15 corresponding to the outdoor 6 outside the veranda 1 and a veranda inner area 16 corresponding to the inside of the veranda 1. The outdoor area 15 is surrounded by a reference line 17 corresponding to the waist wall 3 of the veranda 1, the edge of the ceiling 7, and the edge of the partition plate 4. The outdoor area 15 and the veranda inner area 16 are separated by the reference line 17. Since these areas in the thermal image can be easily set by the user on the software, there is no need for a constructor to perform masking to set the detection area as in the case of a pyroelectric sensor.

[0020] FIG. 6 is a flowchart of the operation of the intrusion determination unit according to Embodiment 1. When an intruder enters the veranda from the outside, as shown in FIG. 5, the heat source that appears in the outdoor area 15 moves to the veranda inner area 16. Therefore, the intrusion determination unit 12 first determines whether there is a heat source 14 with a pixel count and temperature equal to or greater than a threshold value in the outdoor area 15 (step S1). Next, when the center position of the heat source 14 moves from the outdoor area 15 to the veranda inner area 16, the intrusion determination unit 12 determines that "there is an intrusion" (step S2). Note that when the intrusion of a plurality of heat sources is detected, the intrusion determination unit 12 may also detect and notify the number of people.

[0021] There may be cases where a heat source 14 corresponding to the entire body of the intruder cannot be obtained, such as when the intruder is thickly dressed in winter. However, it is not always necessary to identify the entire body of the intruder for intrusion detection. The threshold values for the number of pixels and temperature may be adjusted so that the heat generation locations around the face can be detected. In addition, the intrusion determination unit 12 can improve the detection sensitivity of whether the heat source 14 belongs to the intruder through image processing such as image averaging between frames or edge extraction filters. Note that the intrusion determination unit 12 may learn the information of the intruder in advance by machine learning and use this learning result to detect whether the heat source 14 belongs to the intruder. As a detection method, HOG (Histogram of Oriented Gradient) features using gradient information of luminance values are used, and SVM (Support Vector Machine) or the like is used for learning. Also, a method using deep learning such as SSD (Single Shot Multi Box Detector) or YOLO (You Only Look Once) may be used.

[0022] The determination result output unit 13 is, for example, a display that displays a thermal image, a mobile phone, or a tablet terminal, and notifies the determination result by the determination device 5 to residents, managers, security companies, or the like. The information transmission from the determination device 5 to the determination result output unit 13 is performed by wireless connections such as Wi-Fi (registered trademark), Bluetooth (registered trademark), 4G·5G, or by wired connections such as communication cables or wired LAN.

[0023] As described above, in this embodiment, in the thermal image, the heat source 14 having a pixel count and temperature equal to or higher than the threshold value is detected, and when the center position of the heat source 14 moves from the outdoor area 15 to the veranda area 16, it is determined that "intrusion has occurred". Since whether or not there is an intruder is determined only by whether the temperature and pixel count of the heat source 14 are equal to or higher than the threshold value, the computational load on the intrusion determination unit 12 can be small. Therefore, in a security system that monitors whether or not there is an intrusion into the veranda, the determination device can be miniaturized and power consumption can be reduced.

[0024] Also, in order to determine that "intrusion has occurred" when the heat source 14 moves from the outdoor area 15 to the veranda area 16, the possibility of erroneously detecting a resident who has gone out to the veranda 1 is low. Therefore, it is possible to provide a security system that can be monitored for 24 hours without the need to switch to the security mode. However, when a resident is looking outside from the veranda 1, etc., the heat source 14 is detected in both the outdoor area 15 and the veranda area 16 at the same time. Therefore, it is preferable that the intrusion determination unit 12 determines that "intrusion has occurred" when the heat source 14 moves to the veranda area 16 after being detected only in the outdoor area 15. Thereby, false detection of an intruder can be prevented.

[0025] Also, since the structures of the verandas 1 of each dwelling in an apartment house are often the same, the contents set for the veranda 1 of one dwelling can be applied to other dwellings almost as they are, and system construction is easy.

[0026] Also, for example, when monitoring the shape with a distance image sensor (ToF), etc. and detecting an intrusion, there is a possibility of erroneously detecting a moving inanimate object such as laundry. On the other hand, in this embodiment, since the temperature of the object is detected, there is no fear of erroneously detecting an inanimate object. Also, the ToF sensor may misrecognize the distance in rainy weather, but since the infrared sensor uses light of a long wavelength, it can be monitored with high accuracy even in rainy weather.

[0027] In addition, the determination result output unit 13 outputs the thermal image to an external administrator or security company only when the intrusion determination unit 12 determines that there is an intrusion. In order to output the thermal image, not only the presence or absence of intrusion but also the movement after intrusion can be monitored. By outputting the thermal image only when an intrusion is detected, the movement of the intruder can be monitored from the outside day and night while taking into account the privacy of the residents.

[0028] When there is an intruder near the thermal image acquisition unit 2 by the perspective method, the heat source becomes larger, and when the intruder is further back, the heat source becomes smaller. Therefore, it is preferable to set a larger threshold value for the number of pixels of the heat source 14 in the region closer to the thermal image acquisition unit 2 in the thermal image. However, when the veranda 1 is small, the influence of the perspective method is small, so it is not necessary to change the threshold value of the number of pixels.

[0029] FIG. 7 is a block diagram showing a modification of the security system according to the first embodiment. In FIG. 3, the thermal image acquisition unit 2 and the determination device 5 are mounted in one security camera, but in FIG. 7, the imaging device 18 equipped with the thermal image acquisition unit 2 and the management server 19 equipped with the determination device 5 are separated. The imaging device side transmission / reception unit 20 of the imaging device 18 transmits and receives data with the server side transmission / reception unit 21 of the management server 19. The management server 19 may be in the cloud. The thermal image acquired by the thermal image acquisition unit 2 of the imaging device 18 is transmitted via the Internet or the like and data processing is performed on the management server 19 side. Note that one management server 19 may be provided for a plurality of imaging devices 18.

[0030] FIG. 8 is a diagram showing a first modification of the mounting method of the thermal image acquisition unit of the security system according to the first embodiment. One thermal image acquisition unit 2 is attached to the ceiling at the center of the veranda 1. In order to photograph all of the edge of the ceiling 7, the waist wall 3, the inside of the veranda 1, the window 8, the partition plate 4, etc., it is necessary to use a wide-angle lens for the thermal image acquisition unit 2. In this case, since the distortion of the lens is included in the thermal image, it is necessary to correct the distortion by image processing.

[0031] FIG. 9 is a diagram showing a second modification of the mounting method of the thermal image acquisition unit of the security system according to Embodiment 1. Two thermal image acquisition units 2 are attached to the ceiling at the center of the veranda 1. The two thermal image acquisition units 2 photograph in different directions respectively. However, it is necessary to ensure that the fields of view of both overlap at the center of the veranda 1 so as not to create an area that cannot be photographed.

[0032] Embodiment 2. FIG. 10 is a diagram showing a thermal image in which the setting unit according to Embodiment 2 has set areas. The setting unit 11 sets a window area 22 corresponding to the window 8 and a partition area 23 corresponding to the partition 4 in the thermal image. The window area 22 is surrounded by a reference line 24. The partition area 23 is surrounded by a reference line 25. Note that there may be a plurality of windows 8 or partitions 4. For example, there may be two window areas 22 and two partition areas 23. In that case, the size of each area can be freely set by changing the reference line.

[0033] FIG. 11 is a flowchart of the operation of the intrusion determination unit according to Embodiment 2. After determining that there is an intrusion, the heat source detection unit 9 continues to monitor the position of the heat source 14 to determine the state of the intruder. The storage unit 10 records the movement history of the detected heat source 14 and transmits it to the intrusion determination unit 12. Specifically, the intrusion determination unit 12 checks whether the heat source 14 exists in the veranda inner area 16 (step S3). As long as the heat source 14 exists in the veranda inner area 16, the intrusion determination unit 12 determines that there is an intrusion and continues to issue an alarm.

[0034] If the heat source 14 is no longer detected in the balcony area 16 after the determination that "there is an intrusion," the intrusion determination unit 12 determines the subsequent movement of the intruder based on the last detection position of the heat source 14 (step S4). If the last detection position is the outdoor area 15, the intruder is considered to have escaped from the balcony 1 to the outdoor area 6, and the intrusion determination unit 12 determines that the intruder has "escaped to the outdoor area." If the last detection position is the window area 22, the intruder is considered to have entered the house through the window, and the intrusion determination unit 12 determines that the intruder has "entered the house." If the last detection position is the partition area 23, the intruder is considered to have moved to the adjacent residence via the partition 4, and the intrusion determination unit 12 determines that the intruder has "moved to the adjacent residence." These determination results are notified to the resident, the manager, or the management company by the determination result output unit 13.

[0035] According to this embodiment, after an intruder has invaded the balcony 1, which is difficult to see from the outside, it is possible to know whether the intruder has entered the house through the window 8, moved to an adjacent residence, remained on the balcony 1, or escaped to the outdoors. This reduces the risk of the resident coming face to face with the intruder, and enables the manager or management company to take appropriate action according to the situation. In addition, since the only sensor required is the thermal image acquisition unit 2, there is no need for a complex system that would detect an intruder by attaching sensors to the waist wall 3, the partition board 4, and the window 8. In addition, since the above judgment and notification are made using the detection of an intruder as a trigger, there is no need to go to the trouble of setting the security mode, and it is possible to prevent erroneous operation due to forgetting to turn off the security mode.

[0036] Embodiment 3 12 is a diagram showing an apartment house in which a security system according to embodiment 3 is installed. A thermal image acquisition unit 2 is installed on each of the balconies 1 of the multiple residences in the apartment house, which is made up of consecutive residences such as an apartment building.

[0037] FIG. 13 is a block diagram showing a security system according to Embodiment 3. A thermal image from a thermal image acquisition unit 2 installed on a veranda 1 of each dwelling is input to a determination device 5. When it is determined that there is an intrusion in a veranda 1 of a certain dwelling and the final detection position is determined to be the partition area 23, the thermal image acquisition unit 2 of the veranda 1 of the adjacent dwelling acquires a thermal image, and the intrusion determination unit 12 continuously monitors the position of the heat source 14 in the thermal image to determine the state of the intruder.

[0038] By linking such a monitoring system using the thermal images of adjacent dwellings in this way, even when an intruder moves to an adjacent dwelling through the partition 4, continuous monitoring can be continued. This not only helps to secure the intruder, but also can guide the residents of the adjacent dwelling to evacuate and prevent the residents from coming face to face with the intruder.

[0039] Embodiment 4. FIG. 14 is a diagram showing a thermal image in which an area is set by a setting unit according to Embodiment 4. The setting unit 11 sets a monitoring exclusion area 26 in the thermal image. The intrusion determination unit 12 does not perform monitoring on the heat source 14 existing in the monitoring exclusion area 26.

[0040] For example, an object with a changing temperature such as an outdoor unit of an air conditioner placed on the veranda 1 becomes a heat source or a cooling source. Therefore, an area corresponding to the outdoor unit in the thermal image is set as the monitoring exclusion area 26. Thereby, false detection due to a heat source or a cooling source can be suppressed. Also, in summer, since the floor of the veranda 1 becomes hot, the floor of the veranda 1 may be set as the monitoring exclusion area. Note that when a pyroelectric sensor has been used for monitoring the veranda until now, the construction contractor physically masked the pyroelectric sensor, but such work is not required and the resident can easily set the monitoring exclusion area 26 by software.

[0041] Embodiment 5. FIG. 15 is a block diagram showing a security system according to Embodiment 5. In this embodiment, an imaging device 27 is attached to the entrance of each dwelling. The imaging device 27 operates only when the intrusion determination unit 12 determines that there is an intrusion and enters the alarm mode, and captures an image of the entrance. The imaging device 27 uses an infrared array sensor similar to the thermal image acquisition unit 2, but a visible camera may also be used. When the imaging device 27 detects a person leaving the entrance after an intrusion is detected on the veranda 1, the intrusion determination unit 12 determines that the intruder has escaped from the entrance to the common area, and notifies the same. As a result, it is possible to monitor all the intrusion routes and escape routes of the intruder. Therefore, it is possible to secure the entire apartment building against crime, and it is possible to easily secure the intruder and evacuate the residents.

Description of Reference Numerals

[0042] 1 Veranda, 2 Thermal image acquisition unit, 3 Waist wall, 7 Ceiling, 9 Heat source detection unit, 11 Setting unit, 12 Intrusion determination unit, 13 Determination result output unit, 14 Heat source, 15 Outdoor area, 16 Area inside the veranda, 26 Monitoring exclusion area, 27 Imaging device

Claims

1. A thermal image acquisition unit that captures a veranda to acquire a thermal image; A setting unit that sets, in the thermal image, an outdoor area corresponding to the outside of the veranda and a veranda interior area corresponding to the inside of the veranda; A heat source detection unit that detects a heat source in the thermal image; An intrusion determination unit that determines "intrusion detected" when the center position of the heat source with a pixel count and temperature equal to or higher than a threshold value in the thermal image moves from the outdoor area to the veranda interior area; A crime prevention system comprising a determination result output unit that outputs a determination result by the intrusion determination unit.

2. The crime prevention system according to claim 1, wherein the outdoor area is surrounded by a reference line corresponding to the waist wall and the ceiling edge of the veranda.

3. The crime prevention system according to claim 1 or 2, wherein the intrusion determination unit determines "intrusion detected" when the heat source moves to the veranda interior area after being detected only in the outdoor area.

4. The crime prevention system according to any one of claims 1 to 3, wherein the determination result output unit outputs the thermal image only when the intrusion determination unit determines "intrusion detected".

5. The crime prevention system according to any one of claims 1 to 4, wherein in the thermal image, the threshold value of the pixel count of the heat source is set larger in a region closer to the thermal image acquisition unit.

6. The crime prevention system according to any one of claims 1 to 5, wherein the intrusion determination unit continues to monitor the position of the heat source after determining "intrusion detected" to determine the state of the intruder.

7. The setting unit sets, in the thermal image, a window area corresponding to a window and a partition area corresponding to a partition, After determining "intrusion", when the heat source is no longer detected in the veranda area, if the final detection position of the heat source is in the outdoor area, the intrusion determination unit determines "escaped outdoors", if the final detection position is in the window area, the intrusion determination unit determines "intruded indoors", The security system according to claim 6, wherein when the final detection position is in the partition area, the intrusion determination unit determines "moved to adjacent residence".

8. The thermal image acquisition unit is installed on the verandas of a plurality of residences in an apartment building, For a veranda of a certain residence, when it is determined that there is "intrusion" and the final detection position is determined to be in the partition area, the intrusion determination unit continuously monitors the position of the heat source in the thermal image acquired by the thermal image acquisition unit of the veranda of the adjacent residence to determine the state of the intruder. The security system according to claim 7.

9. The setting unit sets a monitoring-excluded area in the thermal image, The security system according to any one of claims 1 to 8, wherein the intrusion determination unit does not monitor the heat source existing in the monitoring-excluded area.

10. The security system according to any one of claims 1 to 9, further comprising an imaging device that operates when the intrusion determination unit determines "intrusion" and captures an image of the entrance.

11. After the intrusion determination unit determines "intrusion", when the imaging device detects a person leaving the entrance, the intrusion determination unit determines that the intruder has escaped from the entrance. The security system according to claim 10.

12. A step of capturing a veranda by the thermal image acquisition unit to acquire a thermal image, A step of setting, by a setting unit, an outdoor area corresponding to the outside of the veranda and a veranda area corresponding to the inside of the veranda in the thermal image, A step of detecting a heat source in the thermal image by a heat source detection unit; When the center position of the heat source with the number of pixels and temperature equal to or higher than a threshold value in the thermal image moves from the outdoor area to the veranda area, a step of determining "intrusion detected" by an intrusion determination unit; A crime prevention method characterized by comprising a step of outputting the determination result by the intrusion determination unit by a determination result output unit.

Images