JP2012037408A - Infrared-ray human body detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a heat source having a temperature different from the background temperature of space, identify whether the heat source is a human being or not, and output the coordinates of the position of the heat source determined to be a human being, the size, average temperature, maximum temperature, and minimum temperature of a heating element, and the background temperature of the vicinity of the heat source.SOLUTION: The temperature distribution of space is measured using an infrared-ray detecting element arranged two-dimensionally. If a heating element having a temperature different from the temperature of its background is present in the space, the center of the gravity of the heating element is obtained, and the coordinates of the positions of the center of the gravity are stored. If the number of the coordinates of the center of the gravity stored in a set area around the coordinates of the center of the gravity of the heating elements detected successively exceeds a set value, information that the heating element is a human being, the coordinates of the position of the heating element, the size, its average temperature, maximum temperature, and minimum temperature, and the background temperature of the vicinity of a heat source are output.

Description

  The present invention includes two-dimensionally arranged infrared detection elements, detects a heating object by detecting the temperature of the space, and detects position information, size, average temperature, maximum temperature, minimum temperature, background of the detection heating element Output temperature. Furthermore, it is determined whether the heating object is a person or another heating element, and if it is determined that the heating element is a person, information indicating that the heating element is a person, position coordinates, size, average temperature, maximum temperature The present invention relates to an infrared human body detection device that outputs a minimum temperature and a background temperature around a heating element.

  A conventional human body detection device is a human body detection device that measures the temperature of each region of a space with a plurality of thermopile elements arranged in a two-dimensional manner, and detects the presence of a person based on a difference temperature at different measurement times. It is known (see Patent Document 1).

Japanese Patent No. 3805165

  However, in the conventional human body detection device disclosed in Patent Document 1, when there is a heating element that starts to generate heat after turning on the power source of the television or the like in the detection area, a differential temperature on the time axis is generated as the temperature of the television or the like rises. Therefore, there is a problem that a TV or the like is erroneously detected as a human body. In order not to continue the false detection for a long time, if there is no dynamic movement of the heat source for a long time, the human body detection information will be canceled, and the human body that has been working for a long time will not be able to be detected and will become an unattended room .

  The human body detection device according to the present invention repeatedly detects infrared rays emitted from the space and the background using infrared detection elements arranged in two dimensions, measures the temperature distribution of the space by converting the amount of infrared rays into temperature, If a heating element with a temperature different from the background temperature exists in the space, the center of gravity of the heating element is obtained, the position coordinates of the center of gravity are recorded, mapping processing is performed, and the center of gravity coordinates of the detected heating element are centered. When the number of barycentric coordinates recorded in the setting area exceeds the set value, the barycentric coordinates are assumed to be a place where a person is active for a long time, and the heating element detected there is determined to be a person. It outputs position coordinates, size, average temperature, maximum temperature, minimum temperature, and background temperature around the heat source.

  According to the present invention, the human body position can be detected without being confused by the heating element that exists in the human body detection space and fluctuates in temperature, and the position coordinates, size, average temperature, maximum temperature, and minimum temperature of the human body are detected. By obtaining the background temperature around the heat source, the environment in which the human body is placed is comfortable due to the activity status of the human body, the change of the human body surface temperature in time series and the change of the background temperature if the human body is stationary It is possible to obtain information for determining whether the environment is an unpleasant environment, a transition to a comfortable environment, or a transition to an unpleasant environment.

The block diagram of the infrared human body detection apparatus which concerns on the Example of this invention. The figure which memorize | stored the temperature distribution of the space measured with the infrared human body detection apparatus which concerns on the Example of this invention in the memory | storage part 3, and represented in the state of the two-dimensional arrangement | sequence. The figure showing the state of the two-dimensional arrangement | sequence after the labeling process memorize | stored in the memory | storage part 2 of the infrared human body detection apparatus which concerns on the Example of this invention. The figure showing the state of the two-dimensional arrangement | sequence which recorded the locus | trajectory of the gravity center memorize | stored in the memory | storage part 3 of the infrared human body detection apparatus which concerns on the Example of this invention. The figure which started the measurement with the infrared human body detection apparatus based on the Example of this invention, memorize | stored the temperature distribution of the detection space after fixed time passed in the memory | storage part 1, and represented it in the state of the two-dimensional arrangement | sequence. The figure which started the measurement with the infrared human body detection apparatus which concerns on the Example of this invention, memorize | stored the locus | trajectory of the gravity center after the fixed time passed in the memory | storage part 3, and represented it in the state of a two-dimensional arrangement | sequence.

  FIG. 1 is an explanatory diagram of an infrared human body detection device showing an embodiment of the present invention. The case where the two-dimensional infrared detection element 100 is 16 × 16, and a total of 256 infrared detection elements will be described as an example. The two-dimensional infrared detection device divides a detection space into 256 spaces of 16 in length and 16 in width, and the infrared rays emitted from the divided detection space are detected by individual infrared detection elements.

  First, the CPU 102 switches the matrix switch of the two-dimensional infrared detection elements and outputs output signals from the individual infrared detection elements to the signal processing circuit 101. The signal processing circuit 101 amplifies the signal from the infrared detection element, performs A / D conversion, and outputs it to the CPU 102 as digital data. The CPU 102 converts the obtained data into temperature data based on the temperature conversion formula, and then sequentially stores them in the storage units 1 and 103. In the storage units 1 and 103, 16 × 16 = 256 pieces are stored as two-dimensional array data as shown in FIG.

The CPU 102 obtains a histogram of the temperature data in the storage units 1 and 103 when the storage of the entire 256 detection spaces into the storage units 1 and 103 is completed. In the case of the example shown in FIG. 2, a temperature of 25 ° C. at which the distribution is maximum is set as the background temperature.
The CPU 102 uses the obtained background temperature, obtains a threshold temperature for detecting the heat source from a conversion table or a calculation formula, performs comparison operation, binarization, labeling processing with the data in the storage units 1 and 103, the storage unit 2, The labeling processing result is stored in 104 (see FIG. 3). At the same time, the barycentric coordinates of each heat source are calculated. In the example of FIG. 3, the center of gravity coordinates of the upper left heat source are (a5, b3), and the center of gravity coordinates of the lower right heat source are (a11, b10). The number of each label NO at this time is the size of the extracted heat source.

  Next, the CPU 102 writes 1 in (a5, b3) and (a11, b10) as the mapping process of the locus of the center of gravity coordinates in the coordinates of the storage units 3 and 105 that are the same as the center of gravity coordinates of each heat source (see FIG. 4).

  Next, the CPU 102 moves from the periphery (a3, b1) to (a7, b5) around the center of gravity (a5, b3), and from the periphery (a9, b6) to (a13, b12) around (a11, b10). Count how many points you have recorded in the past. In the case of FIG. 4, each heat source is 1 point, and if the human body detection threshold number is set to 10 points or more, the two heat sources are not recognized as human bodies. Since it is not yet known whether the heat source is a human body, the infrared human body detection device sends a mark signal indicating that it is not a human body, and then displays the center of gravity coordinates, size, average temperature, maximum temperature, minimum temperature, and background temperature of the heat source. Output.

  The infrared human body detection apparatus of the present invention repeats the above processing, and in the process of repeating the above processing, the moving heat source, that is, the locus of the center of gravity mapped to the storage units 3 and 105 is gradually expanded in the case of a human body. In the case of a heat source that does not move, the trajectory of the center of gravity slightly expands due to the fluctuation of heat, but does not greatly expand beyond the range of the heat source. At this time, the range for examining the periphery of the center of gravity stored in the storage units 3 and 105 and the number of the center of gravity determined to be a human body are determined in advance by the number of infrared detection elements, the purpose of detecting the human body, and the detection range.

When two heat sources as shown in FIG. 5 are extracted in the process of repeating the process, the center-of-gravity coordinates (a5, b3) and (a10, b10) can be obtained. The locus of these coordinates is stored in the storage unit 3 shown in FIG. At the same time as 105, the number of trajectories of the center of gravity around the area is counted. Since the count number of the heat source having the center-of-gravity coordinates (a5, b3) is 2, which is less than 10 set in advance, this place is not a place where a person is active, and the detected heat source is not recognized as a human body. After sending a mark signal indicating that the heat source extracted at the center of gravity coordinates (a5, b3) is not a human body, the center of gravity coordinate data (a5, b3), size 9, average temperature 30 ° C, maximum temperature 30 ° C, minimum temperature 30 Outputs ℃ and background temperature 25 ℃.
The heat source having the center-of-gravity coordinates (a10, b10) has a count of the number of trajectories of the surrounding center of gravity, and this place is a place where people are active. The heat source detected at this place is determined to be a human body, After sending a mark signal indicating that it is a human body to the connected external device, the center of gravity coordinate data (a10, b10), the size of the heat source 9, the average temperature within the heat source 30 ° C, the maximum temperature 30 ° C, the minimum temperature 30 ° The background temperature of 25 ° C. is output.
The infrared human body detection device according to the present invention is determined not to be a place of human activity because the center of gravity coordinates do not change greatly even if the temperature of the heat source existing at the coordinates (a5, b3) changes, and the heat source detected at this place for a long time. Is not mistakenly detected as a human body.

When the infrared human body detection device of the present invention is used as a sensor of an air conditioner, it is determined whether the temperature environment is comfortable for the human body from the detected background temperature information. For example, the background temperature is unpleasant at 30 ° C. or more. Air conditioning is performed at maximum output so that the environment temperature is the shortest and comfortable in the environment. By extracting the position, size, and temperature of the heat source that is not the human body, the position of the human body, the distribution of the surface temperature of the human body, and the background temperature around the human body, the temperature around the human body can be excessively lowered. This makes it possible to quickly shift to a comfortable and energy-saving driving state.
In addition, if the number of pixels of the infrared detection elements arranged in two dimensions of the infrared detection device of the present invention is increased, it becomes possible to track changes in the center of gravity of the human body more finely, and to move between certain coordinates. It is possible to determine that the human body is in a sleeping state, and by detecting changes in the detection area and fluctuations in the position of the center of gravity, it is possible to detect movements such as turning the human body, and whether it is a REM sleep state or a non-REM sleep state. It is possible to determine whether the result of the room temperature control of the air conditioner can provide a comfortable sleep.

100 Infrared detectors arranged in two dimensions.
101 A signal processing circuit unit that amplifies a signal from an infrared detection element, performs A / D conversion, and outputs the result as data.
102 A control unit that controls the infrared detection element 100 and the signal processing circuit unit to perform various arithmetic processes.
103 A storage unit 1 that converts a signal from the infrared detection element into temperature data and stores it.
104 A storage unit 2 that stores the result of binarizing and labeling the temperature data stored in the storage unit 1.
105 A storage unit 3 that calculates the center of gravity of the data stored in the storage unit 2 and stores mapping information as locus data of the center of gravity.

Claims (4)

  Infrared detectors arranged in a two-dimensional array of at least 16 x 16 elements or more, storage means for converting the infrared intensity radiated from the space detected by each element into a temperature, and storing it as the temperature of each space, and measuring A storage means for taking a histogram of the entire space temperature, extracting a space having a temperature difference between the background temperature and a set temperature as a heat source, using the center temperature of the distribution as a background temperature, obtaining a barycentric coordinate of the extracted heat source, and storing the barycentric coordinate The location where the heat source is detected when the number of centroids stored in the setting area around the centroid coordinates of the newly extracted heat source becomes equal to or greater than the set value while repeating these processes. An infrared human body detection device comprising human body detection means for determining that the extracted heat source is a human body.   When it is determined that the human body, the human body coordinates, the size, the average temperature of the heat source, the maximum temperature, the minimum temperature, and the background temperature around the heat source are output after sending a mark signal indicating the human body. Item 2. The infrared human body detection device according to Item 1.   Even if the extracted heat source is not a human body, after sending a mark signal that it is not a human body, information on the coordinates, size, average temperature, maximum temperature, minimum temperature, background temperature of each extracted heat source The human body detection device according to claim 1, wherein the human body detection device outputs the human body detection device.   The human body detection device according to claim 1, wherein a temperature difference from a background temperature when extracting the heat source is determined by a measured background temperature.

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