Determination device, determination system, determination method, and program

Abstract

To provide a determination device and the like capable of determining the occupancy status of each seat with high accuracy.SOLUTION: A determination device 20 determines the presence or absence of an object to be detected based on an output signal output by an infrared sensor 10 detecting the differential change in infrared light, and is equipped with: a recording unit 21 which records the output time of the output signal each time an output signal is output from the infrared sensor 10; a calculation unit 22 that calculates at least an output time t0 of the output signal recorded in the recording unit 21, an output time t-A1 of the output signal output immediately before the output time t0, an output time tA1 of the output signal output immediately after the output time t0, or a time difference between the output time tA1 and the output time t-A1 of the output signals output immediately before and after the output time t0; a statistical processing unit 23 which outputs statistical values obtained by performing statistical processing on the time difference; and a determination unit 24 that compares the statistical value with a first threshold value for determining the presence or absence of the object to be detected and determines the presence or absence of the object to be detected.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a determination device, a determination system, a determination method, and a program for visualizing the utilization rate of each seat.

Background Art

[0002] In recent years, a device that detects a person using a pyroelectric sensor has been known. For example, Patent Document 1 discloses a detection device including a determination unit that monitors a digital detection signal from a comparator circuit at intervals of 10 μs and determines that a human body has been detected when the digital detection signal continuously indicates five times that a heat source has been detected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional detection device, even when a person is present, if the body movement of the person is small, it is difficult for the sensor to output a sufficient signal, and thus there are cases where it is determined as an absent state. Therefore, it is conceivable to increase the sensitivity of the sensor to output a sufficient signal, but the detection range of the sensor determines that a person is present even when the person simply passes by. For example, when a conventional detection device is applied to each seat in an office, there is a problem that the presence / absence state of each seat cannot be accurately determined.

[0005] The present disclosure solves the above problems and provides a determination device, a determination system, a determination method, and a program capable of accurately determining the presence / absence state of each seat.

Means for Solving the Problems

[0006] A determination device according to one aspect of the present disclosure is a determination device that determines the presence or absence state of a detection target based on an output signal output by an infrared sensor that detects a differential change amount of infrared rays, and each time the output signal is output from the infrared sensor, a recording unit that records the output time of the output signal, the output time t0 of the output signal recorded in the recording unit, and the output time t of the output signal output immediately before the output time t0 -A1 and the output time t of the output signal output immediately after the output time t0 A1 or the output time t of the output signal output immediately before and immediately after the output time t0 A1 and the output time t -A1 and a calculation unit that calculates at least the time difference from, and a statistical processing unit that outputs a statistical value obtained by performing statistical processing on the time difference, and a determination unit that compares the statistical value with a first threshold value for determining the presence or absence state of the detection target and determines the presence or absence state of the detection target.

[0007] Moreover, a determination system according to one aspect of the present disclosure includes a determination device and an infrared sensor that detects a differential change amount of infrared rays.

[0008] Moreover, a determination method according to one aspect of the present disclosure is a determination method that determines the presence or absence state of a detection target based on an output signal output by an infrared sensor that detects a differential change amount of infrared rays, and each time the output signal is output from the infrared sensor, the recording unit records the output time of the output signal, the output time t0 of the output signal recorded in the recording unit, and the output time t of the output signal output immediately before the output time t0 -A1 and the output time t of the output signal output immediately after the output time t0 A1 or the output time t of the output signal output immediately before and immediately after the output time t0 A1 and the output time t -A1 and at least the calculation unit calculates the time difference from, the statistical processing unit outputs a statistical value obtained by performing statistical processing on the time difference, and the determination unit compares the statistical value with a first threshold value for determining the presence or absence state of the detection target and determines the presence or absence state of the detection target.

[0009] Also, a program according to an aspect of the present disclosure enables a computer to execute a determination method.

[0010] Note that the overall or specific aspects of the present disclosure may be realized by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or may be realized by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

Advantages of the Invention

[0011] According to the determination device and the like of the present disclosure, it is possible to accurately determine the presence or absence state of each seat.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Best Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments and the like will be described with reference to the drawings. All of the embodiments and the like described below show comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments and the like are merely examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments and the like, the components not described in the independent claims are described as optional components.

[0014] Also, each figure is a schematic diagram and is not necessarily drawn precisely. In each figure, the same reference numerals are given to substantially the same configurations, and redundant descriptions may be omitted or simplified. Also, in each figure, even when the same object is illustrated, the scale may be changed for convenience.

[0015] (Embodiment) <Function and Configuration> First, with reference to FIGS. 1 to 2B, the configuration of the determination device 20, the determination system 1, the determination method, and the program will be described.

[0016] FIG. 1 is a block diagram showing a determination system 1 according to an embodiment. FIG. 2A is a diagram showing an output signal, an output time, and a time difference. FIG. 2B is a diagram showing a statistical value calculated for each output time and a first threshold value. The horizontal axis of FIG. 2B represents time, and the vertical axis represents the statistical value.

[0017] As shown in FIG. 1, the determination system 1 determines the presence or absence state of the detection target based on the output signal output by the infrared sensor 10 that detects the differential change amount of infrared rays. The detection target is, for example, a dynamic heat source such as a person. For example, by using the infrared sensor 10, the determination system 1 can accurately detect whether a person sitting on each seat arranged in facilities such as an office or a conference room, that is, whether the detection target is in a present state or an absent state. Such an infrared sensor 10 may be installed on each of the seats, or may be installed on the top plate of a desk or the like so as to be able to detect a person sitting on each seat.

[0018] Specifically, the determination system 1 includes an infrared sensor 10 and a determination device 20.

[0019] The infrared sensor 10 has a detection unit 11 and a comparison unit 12.

[0020] The detection unit 11 is, for example, a pyroelectric sensor or the like. The detection unit 11 detects the differential change amount of infrared rays radiated from the detection target at predetermined time intervals. That is, the detection unit 11 detects a heat source. The detection unit 11 outputs an output signal, which is an analog signal indicating that a heat source has been detected, to the comparison unit 12 at predetermined time intervals.

[0021] Each time the comparison unit 12 acquires an output signal from the detection unit 11, the comparison unit 12 compares the output signal output by the detection unit 11 with a second threshold value. That is, the comparison unit 12 compares the output value (for example, output voltage) of the analog output signal output by the detection unit 11 with the second threshold value. After the comparison, the comparison unit 12 determines the presence or absence of a heat source in the detection area where the detection unit 11 can detect the detection target, and outputs a digital output signal indicating the determination result to the determination device 20. The second threshold value is a preset value for determining the presence or absence of a heat source. The heat source includes dynamic heat sources such as people and heat sources other than people that emit infrared rays.

[0022] Note that the comparison unit 12 only determines the presence or absence of a heat source, and does not determine the presence or absence state of the detection target.

[0023] The determination device 20 includes a recording unit 21, a calculation unit 22, a statistical processing unit 23, and a determination unit 24.

[0024] The recording unit 21 is a storage device that records the output time of an output signal every time an output signal is output from the infrared sensor 10. Every time an output signal is output from the infrared sensor 10, the recording unit 21 records an output value of the output signal (e.g., output voltage) in association with the output time. The recording unit 21 also outputs the output time of the output signal to be recorded to the calculation unit 22. The recording unit 21 is realized by, for example, a semiconductor memory.

[0025] As shown in FIG. 1 and FIG. 2A, the calculation unit 22 calculates the output time t0 of the output signal recorded in the recording unit 21 and the output time t of the output signal output immediately before the output time t0. -A1 , the output time t of the output signal output immediately after the output time t A1 , or the output time t A1 and output time t -A1 In this manner, the calculation unit 22 calculates the time difference between the output times of the multiple output signals. -A1 , output time t0, output time t A1 are output signals outputted by the infrared sensor 10 in this order over time, and are signals inputted to the calculation unit 22. The calculation unit 22 outputs each of the calculated time differences to the statistical processing unit .

[0026] As described above, the calculation unit 22 calculates the output time t -A1 , t0, t A1 The time difference is calculated within a section width consisting of three output signals that are connected over time as shown above, but the time difference may be calculated within a section width consisting of two output signals, or within a section width consisting of four or more output signals. The section width is indicated by the number of output signals from the earliest output signal to the final output signal over time. The setting of the section width consisting of output signals will be described later.

[0027] The statistical processing unit 23 calculates a statistical value obtained by performing statistical processing on the time difference calculated by the calculation unit 22, and outputs the calculated statistical value to the determination unit 24. The statistical value is any one of the sum, average value, median value, mode value, maximum value, minimum value, and standard deviation of the information indicating the time difference.

[0028] In addition, as shown in FIGS. 1 and 2B, the statistical processing unit 23 can also calculate an interpolated statistical value obtained by interpolating a time period during which no output signal is output from the infrared sensor 10 based on the output time and the statistical value of the output signal. That is, between the output times of two adjacent output signals, there are blank periods and blank statistical values. Therefore, the statistical processing unit 23 calculates an interpolated statistical value by interpolating the period between two adjacent output signals using a predetermined function. FIG. 2B shows a case where interpolation is performed using a linear function.

[0029] As shown in FIGS. 1 to 2B, for example, the time period during which no output signal is output is defined as the time period between the output time t0 and the output time t A1 and the time period between the output time t0 and the output time t -A1 In this case, the statistical processing unit 23 calculates an interpolated statistical value obtained by interpolating between the output time t0 and the output time t A1 based on the output time t0, the output time t A1 and the statistical value. In addition, the statistical processing unit 23 calculates an interpolated statistical value obtained by interpolating between the output time t0 and the output time t -A1 based on the output time t0, the output time t -A1 and the statistical value.

[0030] The statistical processing unit 23 can also output the interpolated statistical value to the determination unit 24.

[0031] The determination unit 24 compares the statistical value with a first threshold value for determining the presence or absence state of the detection target, and determines the presence or absence state of the detection target. For example, when the statistical value is greater than or equal to the first threshold value, the determination unit 24 determines that the detection target is in the absent state, and when the statistical value is less than the first threshold value, the determination unit 24 determines that the detection target is in the present state.

[0032] Further, the determination unit 24 can also compare an interpolated statistical value interpolated based on the output time and the statistical value when the output signal is output with a first threshold value for a time period during which no output signal is output from the infrared sensor 10, and determine the presence or absence state of the detection target. The setting of the first threshold value will be described later.

[0033] The determination unit 24 outputs the determination result of determining the statistical value and the determination result of determining the interpolated statistical value to an external device. The external device is a server capable of collecting the determination results determined by the determination unit 24 in time series. The external device can, for example, visualize the utilization rate of each seat based on the determination result. Note that the external device may be included in the components of the determination system 1.

[0034] The calculation unit 22, the statistical processing unit 23, and the determination unit 24 are realized by, for example, a large scale integration (LSI) which is an integrated circuit (IC). Note that the integrated circuit is not limited to the LSI, and may be a dedicated circuit or a general-purpose processor. In the embodiment, the calculation unit 22, the statistical processing unit 23, and the determination unit 24 are microcontrollers. The microcontroller includes, for example, a non-volatile memory in which a program is stored, a volatile memory which is a temporary storage area for executing the program, and a processor for executing the program. Further, the calculation unit 22, the statistical processing unit 23, and the determination unit 24 may be a programmable field programmable gate array (FPGA), or a reconfigurable processor in which the connection and setting of circuit cells in the LSI can be reconfigured. The functions executed by the calculation unit 22, the statistical processing unit 23, and the determination unit 24 may be realized by software or by hardware.

[0035] <Operation Example 1> Next, with reference to FIGS. 3 and 4 and the like, an operation example 1 of the determination device 20, the determination system 1, the determination method, and the program according to the embodiment will be described.

[0036] FIG. 3 is a flowchart showing an operation example of the determination system 1 according to the embodiment. FIG. 4 is a diagram showing the output time, time difference, statistical value, first threshold value, and presence / absence state.

[0037] First, as shown in FIGS. 1 and 3, the detection unit 11 of the infrared sensor 10 in the determination system 1 detects the differential change amount of the infrared rays radiated from the detection target at predetermined time intervals, and outputs an analog output signal to the comparison unit 12 of the infrared sensor 10 (S11).

[0038] Next, when the comparison unit 12 acquires the analog output signal from the detection unit 11, it compares the analog output signal (output voltage) output by the detection unit 11 with the second threshold value (threshold voltage), determines the presence or absence of a heat source in the detection area, and outputs a signal indicating the determination result to the determination device 20 (S12). Specifically, the comparison unit 12 compares the output signal with the second threshold value. If the analog output signal output by the detection unit 11 is equal to or greater than the second threshold value, it determines that there is a heat source in the detection area, and outputs an output signal indicating the digital determination result that there is a heat source to the determination device 20. On the other hand, if the analog output signal output by the detection unit 11 is less than the second threshold value as a result of the comparison, the comparison unit 12 determines that there is no heat source in the detection area, and outputs an output signal indicating the determination result that there is no heat source to the determination device 20. Note that when the comparison unit 12 determines that there is no heat source in the detection area, it may not output the determination result to the determination device 20 and end the flowchart of FIG. 3.

[0039] Next, each time an output signal is output from the infrared sensor 10, the recording unit 21 records the output time of the output signal (S13). For example, as shown in FIG. 4, the recording unit 21 records (1) 13:31:10 on June 20, 2023, (2) 13:31:32 on the same day, (3) 13:31:44 on the same day, (4) 13:32:03 on the same day, (5) 14:04:04 on the same day, and (6) 14:12:22 on the same day.

[0040] Next, the calculation unit 22 calculates the time difference between two adjacent output times over time in the output signal recorded in the recording unit 21 (S14). Specifically, the calculation unit 22 determines the output time t0 of the output signal recorded in the recording unit 21 and the output time t -A1 of the output signal output immediately before the output time t0, the output time t A1 of the output signal output immediately after the output time t0, or the output times t A1 and t -A1 of the output signals output immediately before and after the output time t0, respectively, and calculates at least the respective time differences. Further, the calculation unit 22 calculates the time differences with respect to all output signals using the output time t0. Calculating at least the time difference includes calculating the time difference based on the output time t -A1 of the output signal output immediately before the output time t -A2 , the output times of the respective output signals before the output time t -A2 , etc., and also includes calculating the time difference based on the output time t A1 of the output signal output immediately after the output time t A2 , the output times of the respective output signals after the output time t A2 , etc.

[0041] For example, the calculation unit 22 calculates the time difference t1 between the output time t0 and the output time t A1 , and the time difference t -A1 between the output time t0 and the output time t -1 . Also, when considering the output time t -A1 of the output signal output immediately before the output time t -A2 and the output time t A1 of the output signal output immediately after the output time t A2 , the calculation unit 22 calculates the time difference t2 between the output time t0 and the output time t A2 , and the time difference t -A2 between the output time t0 and the output time t -2 . Further, the calculation unit 22 may similarly calculate the time differences for the output times before the output time t -A2 , or may similarly calculate the time differences for the output times after the output time t A2 .

[0042] Specifically, in the above (1), the time difference t0 was 0 seconds, the time difference t1 was 22 seconds, and the time difference t2 was 34 seconds. Also, since the time difference t ー1 t ー2 was not recorded in the recording unit 21, it was not calculated.

[0043] In the above (2), the time difference t ー1 was 22 seconds, the time difference t0 was 0 seconds, the time difference t1 was 12 seconds, and the time difference t2 was 31 seconds. Also, since the time difference t ー2 was not recorded in the recording unit 21, it was not calculated.

[0044] In the above (3), the time difference t ー2 was 34 seconds, the time difference t ー1 was 12 seconds, the time difference t0 was 0 seconds, the time difference t1 was 19 seconds, and the time difference t2 was 32 minutes and 20 seconds.

[0045] In the above (4), the time difference t ー2 was 31 seconds, the time difference t ー1 was 19 seconds, the time difference t0 was 0 seconds, the time difference t1 was 32 minutes and 01 second, and the time difference t2 was 40 minutes and 19 seconds.

[0046] In the above (5), the time difference t ー2 was 32 minutes and 20 seconds, the time difference t ー1 was 32 minutes and 01 second, the time difference t0 was 0 seconds, the time difference t1 was 8 minutes and 18 seconds, and the time difference t2 was 25 minutes and 17 seconds.

[0047] In the above (6), the time difference t ー2 was 40 minutes and 19 seconds, the time difference t ー1 was 8 minutes and 18 seconds, the time difference t0 was 0 seconds, the time difference t1 was 16 minutes and 59 seconds, and the time difference t2 was 17 minutes and 50 seconds.

[0048] The calculation unit 22 outputs each calculated time difference to the statistical processing unit 23. Also, the calculation unit 22 may record the calculated time difference in the recording unit 21.

[0049] Next, the statistical processing unit 23 uses the time differences t -1 t -2And calculate statistical values obtained by performing statistical processing on the time differences t1, t2, etc. (S15). Note that the statistical processing unit 23 uses the output time t -A2 When time differences based on the output times of each of the previous output signals are calculated, even when time differences based on the output times of each of the output signals after the output time t A2 are calculated, statistical values based on these may be calculated.

[0050] For example, the statistical processing unit 23 may calculate a sum as a statistical value by adding up the time differences t -1 , t -2 etc., and the time differences t1, t2, etc.

[0051] Also, the statistical processing unit 23 may calculate a sum by adding up the time differences t -1 , t -2 etc., and the time differences t1, t2, etc., and then calculate an average as a statistical value by dividing the calculated sum by the number of time differences. For example, when using the above time differences, since the number of time differences t1, t2, t -1 , t -2 is four, the statistical value = (t -1 +t -2 +t1+t2) / 4. When considering the time difference for the output time t0, the statistical value = (t -1 +t -2 +(t0 - t0)+t1+t2) / 5 may also be used.

[0052] Specifically, for the time differences in (1) above, the statistical processing unit 23 calculates an average value of 18.7. For the time differences in (2) above, the statistical processing unit 23 calculates an average value of 16.3. For the time differences in (3) above, the statistical processing unit 23 calculates an average value of 41.0. For the time differences in (4) above, the statistical processing unit 23 calculates an average value of 38.0. For the time differences in (5) above, the statistical processing unit 23 calculates an average value of 35.2. For the time differences in (6) above, the statistical processing unit 23 calculates an average value of 41.2.

[0053] Also, the statistical processing unit 23 may calculate the time differences t -1 , t -2The median, mode, maximum value, minimum value, and standard deviation may be calculated from, for example, time differences t1, t2, etc.

[0054] The statistical processing unit 23 outputs the calculated statistical value to the determination unit 24. Further, the statistical processing unit 23 may cause the calculated statistical value to be recorded in the recording unit 21.

[0055] Next, the determination unit 24 compares the statistical value with a first threshold value for determining the presence or absence state of the detection target. That is, the determination unit 24 determines whether the statistical value is less than the first threshold value (S16).

[0056] When the determination unit 24 determines that the statistical value is less than the first threshold value (YES in S16), it outputs a determination result indicating that the detection target is in a present state to the external device (S17). On the other hand, when the determination unit 24 determines that the statistical value is greater than or equal to the first threshold value (NO in S16), it outputs a determination result indicating that the detection target is in an absent state to the external device (S18).

[0057] For example, when the statistical value is the average value and the first threshold value is set to 30 seconds, the determination unit 24 determines that the detection target is in an absent state when the output time of the average value is 30 seconds or more, and determines that the detection target is in a present state when the average value is less than 30 seconds. Therefore, in the case of statistical values 41.0, 38.0, 35.2, 41.2, the determination unit 24 determines that it is in an absent state, and in the case of statistical values 18.7, 16.3, the determination unit 24 determines that it is in a present state.

[0058] Then, the flowchart of FIG. 3 ends.

[0059] In this way, since the external device can acquire the presence or absence state of the detection target at each seat in time series, it can be used to calculate the operating rate of each seat.

[0060] <Operation Example 2> Next, referring to FIGS. 5A and 5B, an operation example 2 of the determination device 20, the determination system 1, the determination method, and the program according to the embodiment will be described. For the operations similar to those in the operation example 1, the same reference numerals will be used and the description will be omitted as appropriate.

[0061] FIG. 5A is a flowchart showing another operation example of the determination system 1 according to the embodiment. FIG. 5B is a flowchart showing another operation example following FIG. 5A of the determination system 1 according to the embodiment.

[0062] In this operation example, since there are blank periods at the output times of the respective output signals, those periods can be interpolated.

[0063] First, as shown in FIG. 5A, in the determination system 1, through S11 to S15, the statistical processing unit 23 calculates an interpolated statistical value based on the output time when the output signal is output and the statistical value for the time period during which no output signal is output from the infrared sensor 10 (S15a). For example, the statistical processing unit 23 calculates an interpolated statistical value by interpolating between the output time t0 and the output time t A1 based on the statistical value, and calculates an interpolated statistical value by interpolating between the output time t0 and the output time t A1 based on the statistical value, and calculates an interpolated statistical value by interpolating between the output time t0 and the output time t -A1 based on the statistical value, and calculates an interpolated statistical value by interpolating between the output time t0 and the output time t -A1 based on the statistical value. The statistical processing unit 23 causes the recording unit 21 to record the calculated interpolated statistical value and outputs it to the determination unit 24.

[0064] Next, the determination unit 24 compares the statistical value with a first threshold value for determining the presence or absence state of the detection target (S16).

[0065] Furthermore, through S17 to S18, as shown in FIG. 5B, the determination unit 24 compares the interpolated statistical value with a first threshold value for determining the presence or absence state of the detection target (S16a).

[0066] When the determination unit 24 determines that the interpolated statistical value is less than the first threshold value (YES in S16a), it outputs a determination result indicating that the detection target is in the present state to an external device (S17a).

[0067] On the other hand, when the determination unit 24 determines that the interpolation statistical value is equal to or greater than the first threshold value (NO in S16a), the determination unit 24 outputs a determination result indicating that the detection target is in an absent state to the external device (S18a).

[0068] Then, the flowcharts of FIGS. 5A and 5B are terminated.

[0069] <Setting of the First Threshold Value> Next, the setting of the first threshold value will be described.

[0070] The setting of the first threshold value may be performed by, for example, the determination unit 24. The first threshold value may be recorded in the recording unit 21 or may be recorded in a memory or the like mounted on the determination unit 24.

[0071] As described above, the first threshold value is a value for determining the presence or absence state. Therefore, in order to improve the accuracy of determining the boundary between the present state and the absent state, the first threshold value should be set appropriately. Thus, in the present embodiment, the first threshold value is set as follows.

[0072] Assuming that the average time interval of the output signals in the present state is a minutes and the average output interval of the false detection signals due to passage or the like is b minutes, the time difference t -2 is 2b, the time difference t -1 is b, the time difference t1 is a, and the time difference t2 is 2a. Therefore, the first threshold value is (2a + a + b + 2b) / 4 = 3(a + b) / 4 minutes. For example, when a is 1 minute and b is 10 minutes, the first threshold value is 3(a + b) / 4 = 8.25 minutes (495 seconds). In this case, it is preferable to set the first threshold value to about 500 seconds.

[0073] Also, in the case of (2a + a + (t0 - t0) + b + 2b) / 5 minutes, the first threshold value is 3(a + b) / 4 = 6.6 minutes (396 seconds). In this case, it is preferable to set the first threshold value to about 400 seconds.

[0074] Note that, as an example of a suitable time for determining the presence / absence state, a = 1 minute and b = 10 minutes were exemplified, but this is merely an example and is not limited to the numerical values of the present embodiment.

[0075] <Setting of Interval Width> Next, with reference to FIGS. 6 and 7, the setting of the interval width will be described.

[0076] FIG. 6 is a diagram for explaining the setting of the interval width. FIG. 7 is a diagram showing the relationship between the interval width, the number of signals affected, and the reduction rate of the hit rate of the present state.

[0077] In FIG. 6, the relationship between the interval width, the number of signals affected according to the interval width, and the reduction rate of the hit rate of the present state is shown. The number of signals affected is counted from the boundary between the present state and the absent state, and is the number of signals whose hit rate of the present state has decreased.

[0078] When the false detection frequency of the infrared sensor 10 is high, it is difficult to determine absence, and the absence hit rate decreases. When the false detection frequency of the infrared sensor 10 is low, the absence hit rate is higher than when the false detection frequency is high. However, even in this case, if the period of the absent state extends over a long period, when changing from the absent state to the present state and when changing from the present state to the absent state, a statistical value is calculated based on the time difference between the first output signal or the last output signal of this present state and the output signal that has drifted over time, so it is considered that the time difference becomes large and the statistical value is affected.

[0079] Therefore, even at the boundary between the present state and the absent state, it is required to accurately determine the presence / absence state of the detection target. Thus, the reduction rate of the hit rate of the present state was investigated according to the length of the interval width.

[0080] Specifically, after 25200 seconds have elapsed in the absent state of the detection target, when the present state is maintained for 3600 seconds, the reduction rate of the hit rate at the boundary between the absent state and the present state according to the length of the interval width was investigated.

[0081] For example, when the interval width is 3, the number of signals affected is 1 counted from the boundary, and the reduction rate of the hit rate in the present state is 1.7%.

[0082] Also, when the interval width is 5, the number of signals affected is 2 counted from the boundary, and the reduction rate of the hit rate in the present state is 3.3%.

[0083] Also, when the interval width is 7, the number of signals affected is 3 counted from the boundary, and the reduction rate of the hit rate in the present state is 5.0%.

[0084] Also, when the interval width is 9, the number of signals affected is 4 counted from the boundary, and the reduction rate of the hit rate in the present state is 6.7%.

[0085] From this, it can be said that at the boundary between the present state and the absent state, it is preferable to determine the present / absent state with the interval width as small as possible.

[0086] <Function and Effect> Hereinafter, the function and effect of the determination device 20, the determination system 1, the determination method, and the program in the present embodiment will be described.

[0087] As described above, the determination device 20 of Technique 1 in the present embodiment is a determination device 20 that determines the present / absent state of a detection target based on an output signal output by an infrared sensor 10 that detects a differential change amount of infrared rays. Each time an output signal is output from the infrared sensor 10, a recording unit 21 that records the output time of the output signal, the output time t0 of the output signal recorded in the recording unit 21, and the output time t of the output signal output immediately before the output time t0 -A1 , the output time t of the output signal output immediately after the output time t0 A1 , or the output time t of the output signal output immediately before and after the output time t0 A1 and the output time t -A1a calculation unit 22 that calculates at least the time difference from [something]; a statistical processing unit 23 that outputs a statistical value obtained by performing statistical processing on the time difference; and a determination unit 24 that compares the statistical value with a first threshold value for determining the presence or absence state of the detection target and determines the presence or absence state of the detection target.

[0088] In this way, in order to calculate a statistical value from each time difference calculated based on the output time of each output signal, the signal density obtained from the number of output signals per certain period is large in the present state, and the variation of each time difference can be reduced (the statistical value obtained by performing statistical processing on the time difference becomes small). On the other hand, when the detection target simply passes in front of the infrared sensor 10, the signal density is small compared to the present state, and the variation of each time difference becomes large (the statistical value obtained by performing statistical processing on the time difference becomes large).

[0089] Thereby, by comparing the statistical value obtained by performing statistical processing on the time difference with the first threshold value, it is possible to determine whether the detection target is in the seat or not in the seat.

[0090] Therefore, according to the present disclosure, it is possible to accurately determine the presence or absence state of each seat.

[0091] As a result, since the presence or absence state of the detection target in each seat can be output in time series, the acquirer can use it to calculate the operation rate of each seat.

[0092] Also, the determination device 20 of Technology 2 in the present embodiment is the determination device 20 described in Technology 1. In this case, the statistical value is any one of the sum, average value, median value, mode value, maximum value, minimum value, and standard deviation of the information indicating the time difference.

[0093] According to this, by using any one of the statistical values, it is possible to accurately determine the presence or absence state of each seat.

[0094] Further, the determination device 20 of Technology 3 in the present embodiment is the determination device 20 described in Technology 1 or 2. In this case, for a time period during which no output signal is output from the infrared sensor 10, the determination unit 24 compares an interpolated statistical value interpolated based on the output time when the output signal is output and the statistical value with a first threshold value, and determines the presence or absence state of the detection target.

[0095] According to this, by calculating the interpolated statistical value for a time period during which no output signal is output from the infrared sensor 10, it is possible to determine the presence or absence state of the detection target in the interpolated statistical value.

[0096] Further, the determination device 20 of Technology 4 in the present embodiment is the determination device 20 described in any one of Technologies 1 to 3. In this case, the time period during which no output signal is output is specified as the time period between the output time t0 and the output time t A1 and the time period between the output time t0 and the output time t -A1 Then, the statistical processing unit 23 interpolates between the output time t0 and the output time t A1 based on the output time t0 and the output time t A1 and the statistical value, and calculates at least one of the interpolated statistical values obtained by interpolating between the output time t0 and the output time t -A1 based on the output time t0 and the output time t -A1 and the statistical value.

[0097] According to this, it is possible to calculate the interpolated statistical value for a time period during which no output signal is output from the infrared sensor 10.

[0098] Further, the determination device 20 of Technology 5 in the present embodiment is the determination device 20 described in any one of Technologies 1 to 4. In this case, the infrared sensor 10 includes a detection unit 11 that detects the differential change amount of infrared rays and outputs an output signal, and a comparison unit 12 that compares the output signal output by the detection unit 11 with a second threshold value, determines the presence or absence of a heat source in the detection region where the detection unit 11 can detect the detection target, and outputs a signal indicating the determination result.

[0099] According to this, the infrared sensor 10 can determine the presence or absence of a heat source within the detection area.

[0100] Moreover, the determination system 1 of Technique 6 in the present embodiment is a determination system 1 including the determination device 20 described in any one of Techniques 1 to 5 and an infrared sensor 10 that detects the differential change amount of infrared rays.

[0101] Also in this determination system 1, the same operational effects as described above are achieved.

[0102] Moreover, the determination system 1 of Technique 7 in the present embodiment is the determination system 1 described in Technique 6. In this case, the infrared sensor 10 is installed so as to be able to detect a detection target in the seated state for each seat.

[0103] According to this, it is possible to accurately detect a detection target sitting on each seat.

[0104] Moreover, the determination method of Technique 8 in the present embodiment is a determination method for determining the presence or absence state of a detection target based on an output signal output by an infrared sensor 10 that detects the differential change amount of infrared rays. Each time an output signal is output from the infrared sensor 10, the recording unit 21 records the output time of the output signal, the output time t0 of the output signal recorded in the recording unit 21, and the output time t of the output signal output immediately before the output time t0 -A1 , the output time t of the output signal output immediately after the output time t0 A1 , or the output time t of the output signal output immediately before and immediately after the output time t0 A1 and the output time t -A1 at least the calculation unit 22 calculates the time difference therebetween, the statistical processing unit 23 outputs a statistical value obtained by performing statistical processing on the time difference, and the determination unit 24 compares the statistical value with a first threshold value for determining the presence or absence state of the detection target and determines the presence or absence state of the detection target.

[0105] This determination method also achieves the same operational effects as described above.

[0106] In addition, the program of Technique 9 in the present embodiment is a program that enables a computer to execute the determination method described in Technique 8.

[0107] This program also exhibits the same operational effects as described above.

[0108] (Other Modifications) As described above, the determination device, determination system, determination method, and program according to the present disclosure have been described based on the above embodiments. However, the present disclosure is not limited to these embodiments. Without departing from the spirit of the present disclosure, various modifications conceived by those skilled in the art applied to the embodiments may also be included within the scope of the present disclosure.

[0109] For example, in the above embodiment, all or part of the components such as the determination device may be configured by dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU (Central Processing Unit) or a processor reading and executing a software program recorded on a recording medium such as an HDD (Hard Disk Drive) or a semiconductor memory.

[0110] Also, the division of the functional blocks in the block diagram is an example, and a plurality of functional blocks may be realized as one functional block, one functional block may be divided into a plurality, or part of the functions may be transferred to other functional blocks. Further, the functions of a plurality of functional blocks having similar functions may be processed by a single piece of hardware or software in parallel or in a time-sharing manner.

[0111] Also, the order in which each step in the flowchart is executed is for illustrative purposes to specifically describe the present disclosure, and may be in an order other than the above. Also, some of the above steps may be executed simultaneously (in parallel) with other steps.

[0112] In addition, forms obtained by making various modifications that occur to those skilled in the art to each of the above embodiments, and forms realized by arbitrarily combining the components and functions in each embodiment without departing from the spirit of the present disclosure are also included in the present disclosure.

Explanation of Signs

[0113] 1 Determination system 10 Infrared sensor 11 Detection unit 12 Comparison unit 20 Determination device 21 Recording unit 22 Calculation unit 23 Statistical processing unit 24 Determination unit

Claims

1. A determination device that determines the presence or absence state of a detection target based on an output signal output by an infrared sensor that detects a differential change amount of infrared rays, a recording unit that records the output time of the output signal each time the output signal is output from the infrared sensor; The output time t of the output signal recorded in the recording unit ０ and the output time t ０ of the output signal output immediately before the output time t －Ａ１ the output time t ０ of the output signal output immediately after the output time t Ａ１ or the output time t ０ of the output signal output immediately before and immediately after the output time t Ａ１ and the output time t －Ａ１ and a calculation unit that calculates at least the time difference with a statistical processing unit that outputs a statistical value obtained by performing statistical processing on the time difference; and a determination unit that compares the statistical value with a first threshold value for determining the presence or absence state of the detection target and determines the presence or absence state of the detection target. Determination device.

2. The statistical value is any one of the sum, average value, median value, mode value, maximum value, minimum value, and standard deviation of information indicating the time difference. The determination device according to claim 1.

3. The determination unit compares an interpolated statistical value interpolated based on the output time and the statistical value at which the output signal is output with the first threshold value for a time period during which the output signal is not output from the infrared sensor, and determines the presence or absence state of the detection target. The determination device according to claim 1 or 2.

4. The time interval during which the output signal is not output is the output time t ０ and the output time t Ａ１ and the output time t ０ and the output time t －Ａ１ and is defined by the time interval between them, The statistical processing unit the output time t ０ and the output time t Ａ１ Based on the output time t ０ and the output time t Ａ１ an interpolated statistical value obtained by interpolating between them, and the output time t ０ and the output time t －Ａ１ Based on the output time t ０ and the output time t －Ａ１ calculate at least one of the interpolated statistical values obtained by interpolating between the output time t The determination device according to claim 3.

5. The infrared sensor includes a detection unit that detects a differential change amount of infrared rays and outputs the output signal, and a comparison unit that compares the output signal output by the detection unit with a second threshold value, determines the presence or absence of a heat source in a detection area where the detection unit can detect the detection target, and outputs a signal indicating the determination result. The determination device according to claim 1 or 2.

6. A determination system comprising the determination device according to claim 1 or 2, and an infrared sensor that detects a differential change amount of infrared rays. Determination system.

7. The infrared sensor is installed so as to be able to detect the detection target present in each seat. The determination system according to claim 6.

8. A determination method for determining the presence or absence state of a detection target based on an output signal output by an infrared sensor that detects a differential change amount of infrared rays, wherein each time the output signal is output from the infrared sensor, a recording unit records the output time of the output signal; The output time t of the output signal recorded in the recording unit ０ and the output time t ０ of the output signal output immediately before the output time t －Ａ１ the output time t ０ of the output signal output immediately after the output time t Ａ１ or the output time t ０ of the output signal output immediately before and immediately after the output time t Ａ１ and the output time t －Ａ１ at least the calculation unit calculates the time difference with a statistical processing unit outputs a statistical value obtained by performing statistical processing on the time difference; and the method includes comparing the statistical value with a first threshold value for determining the presence or absence state of the detection target, and a determination unit determining the presence or absence state of the detection target. Determination method.

9. A program that can be executed by a computer for the determination method according to claim 8. Program.

Images