JP2008224528A - Human body detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a human body accurately without being influenced by an environmental change in a detection area or by a moving direction of a human body. <P>SOLUTION: A detection area corresponding to a thermopile element provided on a human body detection part 20 in the detection area E is defined as a single area, and a detection area including a combination of the single area and a single area in the periphery thereof is defined as a complex area. A differential value showing the difference between a detection value in the single area from the human body detection part 20 and a background value acquired from the detection value when the human body does not exist in the single area is calculated in each single area, and a differential value showing the difference between the sum of detection values in each single area constituting the complex area and the sum of background values in each single area constituting the complex area is calculated, and existence of a human body is discriminated based on comparison between each calculated differential value in the single area and in the complex area and a threshold. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a human body detection device using a thermopile element that senses infrared rays emitted from a human body as a detection object as a detection element, and in particular, an accurate human body without being affected by environmental changes in the detection area or the movement direction of the human body. The present invention relates to a human body detection device capable of detection.

  Conventionally, as a method of detecting the intruder's intrusion into the room, after the infrared ray is absorbed by the light receiving unit having an infrared absorber, the infrared ray is once converted into heat, and the resistance change due to the temperature difference between the light receiving unit and the substrate Thermopile type infrared detecting elements or pyroelectric type infrared detecting elements that take out output as electromotive force or the like are used.

The pyroelectric element is an element that captures changes in heat and is effective when entering at a speed higher than the specified speed.However, when the intruder's operating speed is slow or stationary, the intruder and the background temperature in the space. That is, the difference between the intruder's body temperature and room temperature cannot be distinguished, and the intruder cannot be detected reliably.
On the other hand, a thermopile is a thermocouple composed of two kinds of materials, forming a hot junction on the diaphragm, forming a cold junction on the surrounding heat sink, and providing an insulating protective film on the thermocouple, cold junction and hot junction. A chip configuration is adopted in which an absorption film is provided on the hot junction and used as a sensor unit. For this reason, unlike pyroelectric elements, it is an element that detects the absolute value of heat rather than capturing changes in heat, so it can detect the human body even when the intruder is slow or stationary. Is possible.
And as a human body detection apparatus using such a thermopile element, what is indicated by patent documents 1 is publicly known, for example.

As shown in FIG. 7, a thermopile radiation far-infrared detector 51 for security disclosed in Patent Document 1 includes three or more thermopiles 52, 53, and 54 arranged in an array in different detection spaces via a lens 55. An intruder into the space is detected by detecting the temperatures of 56, 57, and 58, and the output difference between the detected values output from the two thermopiles is extracted, and the output difference extracted between the different thermopile Intruders are detected by comparing each other.
According to the thermopile radiation far-infrared detector 51 for crime prevention, the intruder's intrusion is not detected by detecting the difference between the intruder's body temperature and room temperature as a thermal image, but the far-infrared radiation emitted from the human body is detected. Intrusion is detected without being affected by changes in room temperature because it is detected by the output difference between thermopile.
Japanese Patent No. 3451238

  As described above, in the crime prevention thermopile radiation far-infrared detector of Patent Document 1, when an intruder enters the detection area of any one thermopile, the output difference between the detection values output from the two thermopile The presence of an intruder is detected by comparing the output differences between different thermopiles.

However, in this apparatus, when an intruder enters between two detection areas (for example, between A and B) as shown in FIG. 8, for example, the intruder enters each detection area only slightly. Otherwise, the output difference between the intruding detection areas (difference between the detection areas A and B) and the output difference between the detection areas not entering (the difference between the detection areas B and C, or the detection areas C and A and Difference) may not occur. For this reason, there is a possibility that the output difference between the detection areas is almost the same, and there is a possibility that the intruder cannot be detected and the report is lost.
Also, as shown in FIG. 9, for example, when the detection areas A and B are irradiated with direct sunlight from the sun, a local temperature difference may occur compared to the surrounding environment when a certain amount of time has passed. In such a case, since the presence or absence of a human body is determined by the output difference between the detection areas, there is a possibility that the human body is erroneously detected.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a human body detection device capable of accurately detecting a human body regardless of environmental changes in the detection area and the moving direction of the human body. .

In order to achieve the above-described object, the human body detection device according to claim 1 includes a plurality of thermopile elements that acquire the temperature in the detection area as a detection value based on the amount of infrared light received from the detection area. In the human body detection device that detects the amount of infrared rays in different detection areas for each thermopile element and detects the presence or absence of a human body in the detection area based on the detected value,
A detection area corresponding to each thermopile element in the detection area is a single area, a detection area consisting of a combination of the single area and its surrounding single area is a composite area,
A plurality of the thermopile elements, each of the thermopile elements each outputs a detection value based on the amount of infrared light obtained from the single area,
A difference value that is a difference between a detection value of the single area from the human body detection unit and a background value obtained from a detection value when no human body exists in the single area is calculated for each single area, and A difference value that is a difference between the sum of the detection values of the single area constituting the composite area and the sum of the background values obtained from the detection value when no human body is present in the single area constituting the composite area is calculated. A determination unit that determines the presence or absence of a human body based on a comparison between the calculated difference value of each single area and each composite area and a threshold value;
It is characterized by providing.

The human body detection device according to claim 2 is the human body detection device according to claim 1,
When the difference value between the detection value of the single area and the background value obtained from the detection value when no human body is present in the single area where the detection value is detected exceeds the threshold value for determination start Starting discrimination, and determining that a human body exists in the single area when the difference value of the single area exceeds the human body discrimination threshold within a predetermined time (T1) from the start of discrimination;
Alternatively, when the difference value between the detection value of the composite area and the background value obtained from the detection value when the human body does not exist in the composite area where the detection value is detected exceeds the threshold for starting determination, the human body is determined. It is determined that a human body exists in the composite area when the difference value of the composite area exceeds a human body determination threshold within a predetermined time (T1) from the start of determination.

The human body detection device according to claim 3 is the human body detection device according to claim 2,
When the determination unit determines that there is no human body in the detection area, the detection value at the end of the determination is updated as a background value,
In addition, when the determination unit determines that the human body has left the detection area, the detection value at that time is updated as a background value,
In addition, when the determination unit determines that the difference value between the single area and the composite area does not exceed the determination threshold value, a processing control unit is provided that updates the detection value at that time as a background value. .

The human body detection device according to claim 4 is the human body detection device according to claim 2,
When it is determined that the human body determination threshold is not exceeded within a predetermined time (T1) from the start of human body determination, the determination unit uses the difference between the maximum / minimum detection values in the single area within a predetermined time. A certain fluctuation value is calculated, and the fluctuation value is compared with a predetermined fluctuation value determination threshold value.When the fluctuation value of the single area exceeds the fluctuation value determination threshold value, Determine that the human body exists,
Further, when the fluctuation value of the composite area is calculated, the fluctuation value is compared with the fluctuation value determination threshold, and the fluctuation value of the composite area exceeds the fluctuation value determination threshold, the composite area It is characterized in that it is determined that a human body exists inside.

  According to the human body detection device of the present invention, since the human body is determined by detecting a plurality of single areas set in the detection area E and a composite area in which each single area is arbitrarily combined, the human body is single. Even when passing between areas, it is possible to reliably detect the presence or absence of a human body in the detection area E without detection omission.

  Further, a fluctuation value based on the detection value obtained from the detection area is calculated, and based on the calculated fluctuation value, it is determined whether or not a human body exists in the detection area E, and whether or not the human body has left the detection area E. Therefore, even if the difference between the detected value and the background value is smaller than usual due to environmental changes or the like, the presence or absence of a human body in the detection area can be detected with high accuracy.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a conceptual diagram illustrating a configuration example of the detection area E of the human body detection device according to the present invention, and FIG. 2 is a conceptual diagram illustrating a configuration example of a composite area in the detection area E of the human body detection device according to the present invention. 3 is a schematic block diagram for explaining the configuration of the human body detection device according to the present invention, and FIG. 4 is for explaining the human body discrimination start processing and human body discrimination processing in the processing operation of the human body detection device according to the present invention. FIG. 5 is a flowchart for explaining the stay determination process, the exit determination process, and the background value update process in the processing operation of the human body detection device according to the present invention, and FIG. FIG. 6B is a line graph showing the relationship between the output and time when a human body is detected by the human body detection device according to the present invention, and FIG. Line graph A.

In the following description, as shown in FIG. 1, the detection area E of the human body detection device 1 of this example is set by dividing it into six single areas E1 to E6, and detection is obtained from the amount of infrared rays from each single area. The presence / absence of a human body is determined based on a difference (hereinafter also referred to as a difference value) between the value and a background value of each detection area (a value obtained from a detection value when no human body is present in the area).
As the detection area E, as described above, six independent single areas E1 to E6 and, for example, as shown in FIG. 2, “E1 + E2”, “E2 + E3”, “E4 + E5”, “E5 + E6”, “E1 + E4”, The presence / absence of a human body is determined in each of these areas including a composite area composed of a combination of “E1 + E5”, “E2 + E4”, “E2 + E5”, “E2 + E6”, “E3 + E5”, and “E3 + E6”.
In this example, there are six single areas in the detection area E. However, the present invention is not limited to this, and the number of single areas, the size of the single area range, each single area, depending on the installation location and usage method. The interval, the combination of composite areas, and the like can be set as appropriate. Further, the single areas in FIG. 1 are formed in two lines in a straight line, but may be formed in a staggered pattern, for example.

  First, the configuration of the human body detection device 1 of this example will be described with reference to FIG. As shown in FIG. 3, the human body detection device 1 of this example is schematically configured to include an optical unit 10, a human body detection unit 20, and a signal processing unit 30.

  The optical unit 10 is configured by an optical system such as a convex lens or a concave mirror that collects infrared rays from the single areas E1 to E6. The optical unit 10 outputs infrared rays collected from the single areas E1 to E6 to the human body detection unit 20.

The human body detection unit 20 includes a plurality of thermopile elements that absorb infrared rays with a light receiving unit having an infrared absorber and extract thermal electromotive force according to a temperature difference between the light receiving unit and the substrate as an output. Each single area is configured to have one element. That is, each thermopile element receives infrared rays from different detection areas via the optical unit. The human body detection unit 20 receives the infrared rays collected by the optical unit 10 at a constant sampling period (100 msec in this example), and outputs the heat amount based on the received infrared rays to the signal processing unit 30 as a detection signal. Yes.
In this example, a total of six elements are provided corresponding to each of the single areas 1 to E6. However, the present invention is not limited to this, and the thermopile element is selected according to the number of single areas. The number of installations is also changed as appropriate.

  The signal processing unit 30 is configured by a microcomputer such as a CPU, a ROM, and a RAM, for example. The signal processing unit 30 receives the detection signal output from the human body detection unit 20 and performs various processes and settings related to the determination of the presence or absence of the human body based on the detection value obtained by processing the input detection signal. As shown in FIG. 3, the signal processing unit 30 includes an amplification unit 31, an A / D conversion unit 32, a timing unit 33, a determination unit 34, a storage unit 35, and a processing control unit 36. Is done.

  The amplification unit 31 amplifies the detection signal output from the human body detection unit 20 and outputs the amplified detection signal to the A / D conversion unit 32.

The A / D conversion unit 32 has an A / D conversion function for converting an analog signal into a digital signal, converts the analog detection signal output from the amplification unit 31 into a digital detection signal by A / D conversion, The converted digital detection signal is output to the determination unit 34 as a detection value.
The detection value after the conversion is smoothed by removing noise of the detection signal using a band limiting filter such as a low-pass filter or a high-pass filter that smoothes by removing noise superimposed on the signal. Things are output to the determination unit 34.

  The timekeeping unit 33 is configured by a time measuring device such as a timer, for example, and measures the time during the human body discrimination process under the control of the discrimination unit 34 described later.

  The determination unit 34 includes a single area determination unit 34a and a composite area determination unit 34b, and stores each detection value in the detection area E acquired by the human body detection unit 20 and a storage unit 35 described later. The presence or absence of the human body in the detection area E is determined based on the background value (obtained from the detection value when the human body does not exist in the detection area where the detection value is detected).

The single area discriminating means 34a detects the detection value from each single area output from the A / D conversion unit 32 and the background value of each single area stored in the storage unit 35 for each single area. The difference (difference value) between the value and the background value is calculated, and the presence or absence of the human body in the single area is determined from this difference.
Note that the human body discriminating method in the single area discriminating means 34a includes [human body discriminating start processing], [human body discriminating processing], [stay discriminating processing], [exit discriminating processing], [background value update] in the processing operations described later. Since processing is performed based on [Processing], description of the processing content is omitted.

As described above, the composite area discriminating unit 34b sets, for example, an area composed of an arbitrary combination of one area in each of the single areas E1 to E6 and the surrounding single areas as shown in FIG. Similar to the single area discriminating means 34a, the presence / absence of a human body is discriminated based on the difference value of each composite area. Further, in the composite area discriminating means 34b, when the human body enters between the detection areas (for example, E1 + E2), the human body may not completely enter the detection areas, so that there is a shortage in each detection area. A value obtained by adding the human body ratio to the complement α calculated based on the interval between the detection areas and the size of the area as a weight is used as the detection value.
As for the human body discriminating method of the composite area discriminating means 34b, the same as the single area discriminating means 34a, the following processing operations are [human body discrimination start processing], [human body discrimination processing], [stay discrimination processing], Since processing is performed based on [Exit determination processing] and [Background value update processing], description of the processing content is omitted.

The storage unit 35 is composed of, for example, a rewritable magnetic or optical storage medium or a semiconductor memory such as a ROM or a RAM, and stores various data necessary for driving control of the human body detection device 1 such as an operation history of the human body detection device 1. I remember it. In addition, the storage unit 35 stores the background value obtained from each single area in the detection area E to be compared with the detection value and the background value obtained from the above-described composite area. When the processing control unit 36 outputs an update background value that becomes a new background value corresponding to each background value of the single area or the composite area, the storage unit 35 updates this update. The background value for use is updated and stored as a new background value.
In addition, when the human body detection device 1 is newly installed, since the background value to be compared is not stored, the default background value of each single area obtained in advance during the installation work is stored, This initial background value is used immediately after the device is started.

  Based on the human body discrimination information, stay information, and exit information output from the discrimination unit 34, the process control unit 36 issues various processes related to human body detection, such as issuing an alarm or outputting an operation history by an alarm means (not shown). It is carried out. Further, when an update background value is output from the determination unit 34 (single area determination unit 34a, multiple area determination unit 34b), the processing control unit 36 stores a storage unit corresponding to the output update background value. 35 background values are controlled to be updated.

  Next, a series of processing operations in the above-described human body detection device 1 will be described with reference to FIG. Here, the processing operation of the single area E1 of the single areas E1 to E6 as the detection area E will be described as an example, but the same processing operation is performed for the other single areas E2 to E6 and the composite area.

First, as a human body discrimination start process, a detection value is acquired from the single area E1 (ST1), and a difference (difference value) between the acquired detection value and the background value of the single area E1 is set for a predetermined discrimination start. It is determined whether or not the threshold is exceeded (ST2). When the difference value exceeds the discrimination start threshold value (ST2-Yes), the human body discrimination process is started, and the timer 33 is started simultaneously with the start of the human body discrimination process (ST3). Keep time.
On the other hand, when the difference value does not exceed the discrimination start threshold value (ST2-No), the process proceeds to the background value update process in order to set the detected value at this time as the background value.
The background value used when the human body discrimination process is started is used as it is without being updated until it is determined that no human body is present in the single area E1.

  Next, in the human body determination process, it is determined whether or not the difference (difference value) between the detected value and the background value exceeds a preset human body determination threshold (ST4). When the difference value exceeds the human body determination threshold value (ST4-Yes), it is determined whether or not the human body determination threshold value is exceeded within a predetermined time (T1) from the determination start (ST5). That is, the determination based on the change rate based on the change amount per unit time is performed together with the determination based on the change amount in which the difference value has changed.

  If the human body determination threshold is exceeded within a predetermined time (T1) from the start of determination (ST5-Yes), it is determined that a human body exists in the single area E1, and human body determination information based on the determination result Is output to the processing control unit 36 (ST6).

  Here, when the body temperature of the human body and the temperature in the single area E1 are approximate, even if the difference (difference value) between the detected value and the background value exceeds the discrimination start threshold, this difference value is used for human body discrimination. The threshold may not be exceeded.

Therefore, when it is determined that the human body determination threshold is not exceeded (ST4-No), the fluctuation value of the detection value within the predetermined time (T3) is calculated (ST7).
The fluctuation value is the difference between the maximum / minimum detection values within a certain time. When the human body is present in the single area E1, it must be completely stationary as shown in FIG. 6 (a). Because there is no, there will be some fluctuation. Further, when the single area E1 is affected by environmental changes such as heating and direct sunlight, unlike the case where a human body exists, there is almost no fluctuation as shown in FIG.

  Then, the presence or absence of a human body is determined based on whether or not the calculated fluctuation value exceeds a preset fluctuation value determination threshold (ST8). At this time, when the fluctuation value obtained from the detection value exceeds the fluctuation value determination threshold (ST8-Yes), it is determined that a human body exists, and the human body determination information based on the determination result is obtained as the processing control unit 36. (ST6).

  When it is determined by the human body determination process that a human body exists in the single area E1 (ST5-Yes, ST8-Yes), the stay determination process is performed to determine whether the human body is staying in the single area E1. Transition. On the other hand, if it is determined by the human body determination process that there is no human body in the single area E1 (ST2-No, ST5-No, ST8-No), the process proceeds to the background value update process.

  Next, as shown in FIG. 5, in the stay determination process, when the presence of a human body is determined in the human body determination process (ST5-Yes, ST8-Yes), the human body continuously in the single area E1 for a predetermined time (T2). Is present in the single area E1 (ST9). If the predetermined time (T2) continues (ST9-Yes), it is determined that the human body is staying in the single area E1, and stay information based on the determination result is output to the processing control unit 36. (ST10) The stay determination process is performed again.

  On the other hand, in the stay determination process, when the time determined that the human body exists is less than the predetermined time (T3) (ST9-No), in order to determine whether or not the human body has left the single area E1, Shift to discrimination processing.

In the exit determination process, when it is determined in the stay determination process (ST9) that the human body has not stayed from the single area E1 for a predetermined time, a fluctuation value is calculated from the determined detection value (ST11). It is determined whether or not a state in which the fluctuation value does not exceed the threshold value for exit determination continues for a predetermined time (T4) (ST12). Only when the state where the fluctuation value does not exceed the threshold value for exit determination continues for a predetermined time (T4) (ST12-Yes), it is determined that the human body has exited from the single area E1, and the exit information based on the determination result Is output to the process control unit 36 (ST13), and the process proceeds to the background value update process.
On the other hand, when the state where the fluctuation value does not exceed the threshold for exit determination does not continue for the predetermined time (T4) (ST12-No), the process returns to the initial operation (A) from ST1.

Next, in the background value update process, when it is determined in the human body determination process that there is no human body in the single area E1 (ST2-No, ST5-No, ST8-No), the detected value at the end of each determination As an update background value to the processing control unit 36 to update the background value (ST15).
Further, in the exit determination process, when it is determined that the human body has exited and the exit information is output to the process control unit 36 (ST13), the timing of the time measuring unit 33 is stopped and the exit determination process is terminated (ST14). In order to update the detection value at the end of the exit determination process as the latest background value, this detection value is output to the process control unit 36 as an update background value to update the background value (ST15).
Furthermore, when the difference (difference value) between the detected value and the background value does not exceed the threshold for determination and the body determination process is not performed (ST2-No), the detected value at that time is updated as the latest background value. The detected value is output as an update background value to the processing control unit 36, and the background value is updated (ST15).

Thus, the human body detection device 1 described above receives infrared rays from each area in the detection area E, and acquires a detection value from the detection signal based on the received amount of infrared rays. Then, a difference (difference value) between the detected value and the background value of the detection area E from which the detected value is acquired is calculated, and a single area discriminating unit based on the difference value, a discrimination start threshold value, and a human body discrimination threshold value 34a and the complex area discriminating means 34b perform [human body discrimination start processing], [human body discrimination processing], [stay discrimination processing], [exit discrimination processing], and [background value update processing], respectively. The presence or absence of a human body in E is determined.
That is, since the human body detection device of the present invention performs human body discrimination using each single area of the detection areas E1 to E6 and a composite area arbitrarily combining the detection areas E1 to E6 as a detection target, for example, the detection area Even when a human body enters between each single area such as between E1 and E2 or between E1 and E4, it is possible to detect a human body that has entered between each single area.
Therefore, when a human body enters the detection area E, the presence or absence of the human body in the detection area E can be reliably detected without omission of detection.

Also, in ST7 in the processing operations of FIGS. 4 and 5 described above, a fluctuation value based on the detected value is calculated, and whether or not the calculated fluctuation value exceeds a preset fluctuation value determination threshold value in the detection area E In ST10, a fluctuation value based on the detected value is calculated, and the human body detects whether or not the calculated fluctuation value does not exceed the exit determination threshold for a predetermined time (T5). It is determined whether the user has left the area E.
For this reason, even if the difference between the detection value and the background value is smaller than usual due to environmental changes or the like, the presence or absence of a human body in the detection area can be detected with high accuracy.

  By the way, in the operation process shown in FIG. 4, a threshold for starting discrimination is set for determining a heat source variation in which noise and a human body are not limited, but the process of ST2 is omitted and a detection value is acquired from the detection area E (ST1) It is also possible to start the timekeeping unit together with the start of the human body discrimination process and time the human body discrimination state (ST3).

  As mentioned above, although the best form in this invention was demonstrated, this invention is not limited with the description and drawing by this form. That is, it is a matter of course that all other forms, examples, operation techniques, and the like made by those skilled in the art based on this form are included in the scope of the present invention.

It is a conceptual diagram which shows the structural example of the detection area E of the human body detection apparatus which concerns on this invention. It is a conceptual diagram which shows the structural example of the composite area in the detection area E of the human body detection apparatus which concerns on this invention. It is a schematic block diagram for demonstrating the structure of the human body detection apparatus which concerns on this invention. It is a flowchart for demonstrating a human body discrimination | determination start process and a human body discrimination | determination process in the processing operation of the human body detection apparatus which concerns on this invention. It is a flowchart figure for demonstrating the stay discrimination | determination process, the exit discrimination | determination process, and background value update process in the processing operation of the human body detection apparatus concerning this invention. (A) It is a line graph which shows the relationship between the output at the time of detecting a human body with the human body detection apparatus which concerns on this invention, and time. (B) It is a line graph which shows the relationship between the output by an environmental change, and time in the human body detection apparatus which concerns on this invention. It is a schematic explanatory drawing of the conventional thermopile radiation far-infrared detector. It is a conceptual diagram which shows the example of arrangement | positioning of the detection area in the conventional detection apparatus. It is explanatory drawing which shows the example which a part of detection area in the conventional detection apparatus irradiated with the direct sunlight.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Human body detection apparatus 10 Optical part 20 Human body detection part 30 Signal processing part 31 Amplification part 32 A / D conversion part 33 Timekeeping part 34 Discriminating part 34a Single area discriminating part 34b Complex area discriminating part 35 Storage part 36 Processing control part

Claims (4)

A plurality of thermopile elements that acquire the temperature in the detection area as a detection value based on the amount of infrared light received from the detection area, each of the plurality of thermopile elements detects the amount of infrared light in a different detection area, and the detected In a human body detection device that detects the presence or absence of a human body in the detection area based on a detection value,
A detection area corresponding to each thermopile element in the detection area is a single area, a detection area consisting of a combination of the single area and its surrounding single area is a composite area,
A plurality of the thermopile elements, each of the thermopile elements each outputs a detection value based on the amount of infrared light obtained from the single area,
A difference value that is a difference between a detection value of the single area from the human body detection unit and a background value obtained from a detection value when no human body exists in the single area is calculated for each single area, and A difference value that is a difference between the sum of the detection values of the single area constituting the composite area and the sum of the background values obtained from the detection value when no human body is present in the single area constituting the composite area is calculated. A determination unit that determines the presence or absence of a human body based on a comparison between the calculated difference value of each single area and each composite area and a threshold value;
A human body detection device comprising: When the difference value between the detection value of the single area and the background value obtained from the detection value when no human body is present in the single area where the detection value is detected exceeds the threshold value for determination start Starting discrimination, and determining that a human body exists in the single area when the difference value of the single area exceeds the human body discrimination threshold within a predetermined time (T1) from the start of discrimination;
Alternatively, when the difference value between the detection value of the composite area and the background value obtained from the detection value when the human body does not exist in the composite area where the detection value is detected exceeds the threshold for starting determination, the human body is determined. 2. The method according to claim 1, wherein when the difference value of the composite area exceeds a human body determination threshold value within a predetermined time (T 1) from the start of determination, it is determined that a human body exists in the composite area. Human body detection device. When the determination unit determines that there is no human body in the detection area, the detection value at the end of the determination is updated as a background value,
In addition, when the determination unit determines that the human body has left the detection area, the detection value at that time is updated as a background value,
Furthermore, when the determination unit determines that the difference value between the single area and the composite area does not exceed the determination threshold value, a processing control unit is provided that updates the detection value at that time as a background value. The human body detection device according to claim 2. When it is determined that the human body determination threshold is not exceeded within a predetermined time (T1) from the start of human body determination, the determination unit uses the difference between the maximum / minimum detection values in the single area within a predetermined time. A certain fluctuation value is calculated, and the fluctuation value is compared with a predetermined fluctuation value determination threshold value.When the fluctuation value of the single area exceeds the fluctuation value determination threshold value, Determine that the human body exists,
Further, when the fluctuation value of the composite area is calculated, the fluctuation value is compared with the fluctuation value determination threshold, and the fluctuation value of the composite area exceeds the fluctuation value determination threshold, the composite area The human body detection device according to claim 2, wherein it is determined that a human body is present in the body.

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