JP5724370B2 - Human body detection device and human body detection method - Google Patents

Description

  The present invention relates to an infrared human body detection device and a human body detection method.

  Infrared type human body detection devices that detect the presence or absence of a person using a pyroelectric infrared sensor that outputs an electrical signal corresponding to the amount of change in infrared rays incident from the human body have been known, for example, for crime prevention It is used for intrusion detection devices and automatic lighting switches. As such an infrared human body detection device, Patent Document 1 discloses an object detection device that can suppress erroneous detection even when background noise having a large level exceeding a threshold value occurs. In this object detection device, the waveform of the background noise shows gentle characteristics for both rising and falling, whereas the waveform of the human body detection signal is sharp for both rising and falling, which is clearly different from the waveform of the background noise. Paying attention to the characteristic, the detection output of the infrared detection unit corresponding to the amount of fluctuation of the infrared ray radiated from the predetermined detection area is continuously included between the first threshold value and the second threshold value. It is determined whether or not an object exists in a predetermined detection area based on the remaining time.

  Patent Document 2 discloses a human body detector that can set an appropriate determination time according to the speed of a moving object each time a change in the amount of infrared light is detected, and that can prevent false alarms and prevent false alarms. Has been. In this human body detector, a predetermined determination time is measured after detecting a change in which the amount of change in infrared rays exceeds a threshold for human body detection, and a change in which the amount of change in infrared rays exceeds a threshold for human body detection within this determination time. Is detected as a human body. More specifically, in this human body detector, first, the variation time from when the change amount of the infrared ray detected from the set monitoring area deviates from a predetermined normal range until it returns to the normal range is measured. . Next, the determination time is set using the variation time measured when the change exceeding the threshold for human body detection is first detected. When a change exceeding the human body detection threshold is detected within the set determination time, the human body is determined.

JP 2004-117250 A JP 2001-86262 A

By the way, in recent years, from the viewpoint of CO ₂ emission reduction and the like, there is a social demand for lower power consumption (energy saving) of electrical equipment. For this purpose, for example, an electric device that detects the presence or absence of a person with a human body detection device, turns on the power when a person is present, and automatically turns off the power when the person is absent has been put into practical use. At that time, for example, there is a demand to detect only the presence or absence of a person sitting in a predetermined area without detecting a person walking behind. However, since the detection devices described in Patent Documents 1 and 2 described above cannot distinguish between a seated person and a person passing behind, not only a seated person but also a person passing behind are detected. End up. As a result, there is a problem that in an unnecessary situation, the power source of the electric device is turned on and the energy saving effect is reduced.

  The present invention has been made to solve the above problems, and a human body detection device and a human body detection method capable of selectively detecting only the presence or absence of a person who stays in a predetermined area continuously The purpose is to provide.

  The inventors of the present application have conducted extensive studies on the above problems, and as a result, for example, when a person is seated in a chair or when a person moves from a away state to a seated state, the output of the infrared sensor On the other hand, when humans or small animals pass a little away, the output of the infrared sensor converges in a short time and the knowledge is returned to the steady state.

  Therefore, the human body detection device according to the present invention includes an infrared sensor that outputs an electrical signal corresponding to the amount of change in infrared, and a comparison unit that outputs a detection signal when the electrical signal output from the infrared sensor exceeds a threshold value. Each time the detection signal is output, the time measuring means for measuring the elapsed time since the detection signal was output, and the detection signal at a time interval shorter than a predetermined time based on the elapsed time measured by the time measuring means. Determining means for determining whether or not an event is repeatedly generated, and determining that there is a person who remains in a predetermined area when it is recognized that the event has repeatedly occurred It is characterized by providing.

  Further, the human body detection method according to the present invention includes a comparison step of outputting a detection signal when the electrical signal output from the infrared sensor that outputs an electrical signal corresponding to the amount of change in infrared exceeds a threshold, and the detection signal An event in which a detection signal is output at an interval shorter than a predetermined time based on the time measuring step for measuring the elapsed time since the detection signal is output and the elapsed time measured in the time measuring step each time it is output A determination step for determining whether or not there is a person who has remained in a predetermined area when it is determined that the event has occurred repeatedly. Features.

  As described above, for example, when a person is seated in a chair or when a person moves from a away state to a seated state, the fluctuation of the output of the infrared sensor lasts for a certain period of time (that is, the detection signal is repeated). Output). On the other hand, when a person or a small animal passes a little away, the output of the infrared sensor converges in a short time and returns to a steady state (that is, no detection signal is output). According to the human body detection device or the human body detection method of the present invention, each time a detection signal is output, the elapsed time from the output of the detection signal is counted, and the detection signal is transmitted at a time interval shorter than a predetermined time. When it is output repeatedly, it is determined that there is a person who stays in the predetermined area continuously. That is, when the output fluctuation of the infrared sensor continues, it is determined that there is a person who stays in a predetermined area continuously. Therefore, for example, it is possible to detect only the presence or absence of a person sitting in a predetermined area without discriminating between a person sitting and a person passing behind and detecting a person passing behind. That is, it is possible to selectively detect only the presence / absence of a person who stays in a predetermined area. In addition, according to the human body detection apparatus or human body detection method which concerns on this invention, since the noise which generate | occur | produces once can also be removed, the false detection by noise can also be reduced.

  In the human body detection device according to the present invention, when the determination means determines that there is a person staying in the predetermined area, if the detection signal is not continuously output for the first predetermined time, the second When the detection signal is not output continuously for a predetermined time, it is determined that there is no person staying in the predetermined area, and when the detection signal is output before the second predetermined time elapses, When it is recognized that an event in which the detection signal is output repeatedly at a time interval shorter than the fourth predetermined time from when the detection signal is output until the third predetermined time elapses. When it is determined that there is a person who stays in the predetermined area and the event does not occur repeatedly until the third predetermined time elapses, a person who stays in the predetermined area It is preferable to judge that there is no .

  Further, in the human body detection method according to the present invention, in the state where it is determined in the determination step that there is a person staying in the predetermined area, when the detection signal is not continuously output for the first predetermined time, When the detection signal is not output continuously for the second predetermined time, it is determined that there is no person staying in the predetermined area, and the detection signal is output before the second predetermined time elapses. When it is recognized that the event in which the detection signal is output repeatedly at a time interval shorter than the fourth predetermined time from when the detection signal is output until the third predetermined time elapses. The person staying in the predetermined area when it is determined that there is a person staying in the predetermined area and the event has not occurred repeatedly until the third predetermined time has elapsed. Judge that there is no Door is preferable.

  In this case, in a state where it is determined that there is a person who remains in the predetermined area, the detection signal is not output continuously for the first predetermined time, and the detection signal is further output for the second predetermined time. When it is not output, it is determined that no one remains in the predetermined area. On the other hand, even if the detection signal is not output continuously for the first predetermined time, if the detection signal is output before the second predetermined time elapses, the detection signal is output. A person who remains in the predetermined area when the detection signal is repeatedly output at a time interval shorter than the fourth predetermined time until the third predetermined time elapses. It is determined that there is. That is, when the output fluctuation of the infrared sensor continues for the third predetermined time, it is determined that there is a person who stays in the predetermined area continuously. On the other hand, if the detection signal is not repeatedly output at a time interval shorter than the fourth predetermined time until the third predetermined time elapses, there is no person staying in the predetermined area. Determined. Therefore, from the state where there is a person staying in the predetermined area, it is reliably determined whether or not there is no person staying in the predetermined area (for example, whether the person who was seated has left). It becomes possible.

  In the human body detection device according to the present invention, when the detection signal is output in a state where it is determined that there is no person staying in the predetermined area, the determination unit starts from the time when the detection signal is output. Until the fifth predetermined time elapses, when it is recognized that an event in which the detection signal is output at a time interval shorter than the sixth predetermined time is repeatedly generated, it remains in the predetermined area. When it is determined that there is a person and the event does not occur repeatedly until the fifth predetermined time has elapsed, it is preferable to determine that there is no person remaining in the predetermined area.

  In the human body detection method according to the present invention, when the detection signal is output in the state where it is determined in the determination step that there is no person staying in the predetermined area, the detection signal is output. If it is recognized that an event in which a detection signal is output at a time interval shorter than the sixth predetermined time has occurred repeatedly until the fifth predetermined time elapses from the time point, it remains within the predetermined region. Determining that there is no person who remains in the predetermined area when the event does not occur repeatedly until the fifth predetermined time elapses. preferable.

  In this case, in a state where it is determined that there is no person staying in the predetermined area, when the detection signal is output, until the fifth predetermined time elapses after the detection signal is output, When the detection signal is repeatedly output at a time interval shorter than the sixth predetermined time, it is determined that there is a person who stays in the predetermined region continuously. That is, when the output fluctuation of the infrared sensor is continued for the fifth predetermined time, it is determined that there is a person who stays in the predetermined area continuously. On the other hand, if the detection signal is not repeatedly output at a time interval shorter than the sixth predetermined time until the fifth predetermined time elapses, there is no person remaining in the predetermined area. Determined. Therefore, it is possible to reliably determine whether or not a person has entered the predetermined area and stayed (for example, whether or not a person has been seated) from a state in which no person remains in the predetermined area.

  The human body detection device according to the present invention preferably includes an output unit that outputs a determination result by the determination unit.

  Moreover, it is preferable that the human body detection method according to the present invention further includes an output step for outputting a determination result in the determination step.

  In this case, only the determination result, that is, the presence / absence of a person (for example, a seated person) staying within a predetermined area is output. That is, even if there is a person who passes behind, it can be excluded. Therefore, for example, when it is configured to turn on / off the electric device according to the output determination result, it prevents the electric device from being turned on in an unnecessary situation and reducing the energy saving effect. It becomes possible to do.

  In the human body detection device according to the present invention, when it is determined that there is a person who remains in the predetermined area, the comparison unit determines that there is no person who remains in the predetermined area. It is preferable to make it lower than when it is in a closed state.

  Further, in the human body detection method according to the present invention, when it is determined that there is a person who remains in the predetermined area, there is no person who remains in the predetermined area in the comparison step. It is preferable to make it lower than when it is determined to be.

  In this case, when there is a person who stays in the predetermined area, the threshold value is made lower than when there is no person who stays, and the detection sensitivity is increased. For example, in the seated state, it is desired to detect even a small movement that moves the head, but if the sensitivity is increased, it becomes easier to pick up noise in the away state. Therefore, when a person moves from an unattended state to a seated state, he notices that there will be a large movement and the output of the infrared sensor will increase, and when in the seated state, by lowering the threshold than in the unattended state, In this case, the sensitivity can be increased to detect small movements, while the sensitivity can be decreased in the absence state to reduce the influence of noise.

  The human body detection device according to the present invention can vary the amplification factor, and is in a state where it is determined that there is an amplifier that amplifies an electric signal output from the infrared sensor and a person who remains in a predetermined region. In some cases, it is preferable to include switching means for making the amplification factor of the amplifier larger than when it is determined that there is no person remaining in the predetermined region.

  In addition, the human body detection method according to the present invention sets the amplification factor of the amplifier that amplifies the electrical signal output from the infrared sensor when it is determined that there is a person staying in the predetermined region. It is preferable to provide a switching step that is larger than when it is determined that there is no person remaining in the area.

  In this case, when there is a person who stays in the predetermined region, the amplification factor of the amplifier is made larger than when there is no person who stays, and the detection sensitivity is increased. Thus, for example, in the seated state, by increasing the amplification factor than in the away state, the sensitivity is increased in the seated state and small movements can be detected, while the sensitivity is lowered in the away state to reduce the influence of noise. It becomes possible to reduce.

  In the human body detection device according to the present invention, a dual-type pyroelectric infrared sensor having two pyroelectric elements connected in series so that the polarities are reversed is preferably used as the infrared sensor.

  According to the present invention, when the detection signal is repeatedly output at a time interval shorter than the predetermined time, it is determined that there is a person who stays in the predetermined area continuously. It becomes possible to selectively detect only the presence or absence of a person who stays in the area continuously.

It is a block diagram which shows the structure of the human body detection apparatus which concerns on embodiment. It is a state transition diagram of the determination state by the human body detection apparatus according to the embodiment. It is a flowchart which shows the process sequence of the human body detection process (seating state process) in a seating state by the human body detection apparatus which concerns on embodiment. It is a flowchart which shows the process sequence of the human body detection process (seating determination process) in the absence determination state by the human body detection apparatus which concerns on embodiment. It is a flowchart which shows the process sequence of the human body detection process (seating state process) in a away state by the human body detection apparatus which concerns on embodiment. It is a flowchart which shows the process sequence of the human body detection process (seating determination process) in the seating determination state by the human body detection apparatus which concerns on embodiment. It is a figure (seating determination) for demonstrating the seating determination process / absence determination processing by the human body detection apparatus which concerns on embodiment. It is a figure (seating determination) for demonstrating the seating determination process / absence determination processing by the human body detection apparatus which concerns on embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, the configuration of the human body detection device 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of the human body detection device 1.

  The human body detection device 1 selectively detects only the presence or absence of a person who stays in a predetermined area among persons existing in the detectable area. For example, the human body detection device 1 is used by being connected to or built in a monitor of a personal computer placed on a desk. In such a case, the human body detection device 1 does not detect a person who walks past the chair provided on the desk, and selectively selects only the presence or absence of the person sitting on the chair in front of the desk. And automatically turn the monitor power on and off according to the detection result. Hereinafter, the phrase “seating and leaving” is used as an example of “staying in a predetermined area, not staying in a predetermined area”.

  For this purpose, the human body detection device 1 outputs an electrical signal corresponding to the amount of change in infrared rays incident from a human body (including a part of the human body) and the like, and is output from the infrared detector 10. And a signal processing unit 20 that processes the electrical signal (output signal) and detects the presence or absence of a person (for example, a person who is seated) continuously in a predetermined area. The infrared detector 10 includes a condensing unit 11, a dual type pyroelectric infrared sensor 12, an amplifying unit 13, and a band filter (band pass filter) 14. The signal processing unit 20 includes an A / D conversion unit 21, a comparison unit 22, a first timer 23, a second timer 24, a state determination unit 25, an output unit 26, and a switching unit 27. Hereinafter, each configuration will be described in detail.

  The condensing unit 11 includes a multi-segment lens. Infrared light emitted from the human body is collected by the multi-segment lens of the light collecting unit 11 and input to the dual type pyroelectric infrared sensor 12.

  The dual-type pyroelectric infrared sensor 12 has two pyroelectric elements connected in series so that the polarities are reversed, and the difference in the amount of change in infrared incident on each of the two pyroelectric elements. A motion signal is output as a detection signal. That is, the dual type pyroelectric infrared sensor 12 corresponds to the infrared sensor described in the claims. The dual type pyroelectric infrared sensor 12 is connected to the amplifying unit 13, and the electrical signal output from the dual type pyroelectric infrared sensor 12 is input to the amplifying unit 13.

  The amplifying unit 13 amplifies an electric signal input from the dual type pyroelectric infrared sensor 12, and a programmable gain amplifier capable of dynamically changing an amplification factor (gain) is preferably used. The amplifying unit 13 corresponds to the amplifier described in the claims. Here, when an external programmable gain amplifier is used, an input port on the amplifier side provided for accepting the setting and an output port of the microprocessor are connected, and the port output (Hi) of the microprocessor is connected. , Lo), the gain is switched. Details of the switching will be described later. On the other hand, when a programmable gain amplifier with a built-in microcomputer is used, the amplification factor is changed by rewriting the microcomputer register (setting) in software. The electric signal amplified by the amplifying unit 13 is output to the band filter 14.

  The band filter 14 removes a frequency component (noise component) that is unnecessary for detecting a human body from the electrical signal output from the amplifying unit 13. In the present embodiment, a bandpass filter having a passband of 1 Hz to 30 Hz is used. In addition, it is good also as a structure which removes noise by performing a filtering process using a digital filter after A / D conversion. The electrical signal (output signal) output from the band filter 14 is output to the signal processing unit 20.

  As described above, the signal processing unit 20 processes the output signal input from the infrared detector 10 and detects the presence or absence of a person (for example, a person who is seated) continuously in a predetermined area. To do. The signal processing unit 20 includes an A / D converter 21, a microprocessor that performs arithmetic processing on an output signal input via the A / D converter 21, and causes the microprocessor to execute each process. A ROM for storing the programs and data, a RAM for temporarily storing various data such as calculation results, and a backup RAM for backing up the data. In the signal processing unit 20, the program stored in the ROM is executed by the microprocessor, whereby the comparison unit 22, the first timer 23, the second timer 24, the state determination unit 25, the output unit 26, and the switching unit The function of the unit 27 is realized. Note that the microprocessor, the ROM, the RAM, and the like may be configured by independent chips, or may be configured by a microcomputer (microcomputer) housed in one chip.

  The A / D converter 21 includes an A / D converter, and converts an output signal (analog signal) output from the infrared detector 10 (band filter 14) into digital data at a predetermined sampling period. The digitally converted output signal is output to the comparison unit 22.

  The comparison unit 22 compares the value of the output signal of the infrared detector 10 converted into a digital value with a predetermined threshold value set in advance, and when the value of the output signal is larger than the threshold value, a human body is detected. The detection signal which shows that is output. That is, the comparison unit 22 functions as a comparison unit described in the claims. Here, since the output signal of the infrared detector 10 (dual type pyroelectric infrared sensor 12) changes in the plus direction and the minus direction with respect to the steady state (see FIGS. 7 and 8), the threshold value is steady. Two threshold values are set: a first threshold value on the plus side of the state (first threshold value in FIGS. 7 and 8) and a second threshold value on the minus side (second threshold value in FIGS. 7 and 8). Therefore, the comparison unit 22 outputs a detection signal when the value of the output signal of the infrared detector 10 that has been digitally converted exceeds the first threshold and when it falls below the second threshold. In addition, it is good also as a structure which takes the absolute value of an output signal and compares only with the 1st threshold value on the plus side. The detection signal generated by the comparison unit 22 is output to the state determination unit 25.

  As shown in FIG. 2, the state determination unit 25 takes four determination states (a seating state 100, a leaving determination state 110, a leaving state 120, and a seating determination state 130), and between these four determination states. Transition and determine the presence or absence of a seated person. Here, the seating state 100 is a state in which it is determined that there is a person who stays in the predetermined area (here, a person who is seated), and the absence determination state 110 remains in the predetermined area. This is a state in which it is determined whether or not the person (seated person) has disappeared (whether or not he / she has left). In addition, the away state 120 is a state in which it is determined that there is no person (a person who is seated) in the predetermined area, and the seating determination state 130 is that a person has entered the predetermined area and stayed there. In this state, it is determined whether or not the user has been seated.

  In the seating state 100, the seating determination state 110, and the seating determination state 130, the state determination unit 25 transitions from the seating state 100 to the seating determination state 110 and the elapsed time after the detection signal is output. In the first timer 23 that counts the elapsed time since the start, and in the absence determination state 110 and the seating determination state 130, every time a detection signal is output, the first timer 23 that measures the elapsed time since the detection signal was output. 2 timer 24 (corresponding to the timing means described in the claims). The state determination unit 25 determines the presence / absence of a person (a person who is seated) who stays in a predetermined area continuously based on the detection signal and the states of the first timer 23 and the second timer 24.

  When the detection signal is output in the seated state 100, the state determination unit 25 sets a first predetermined time (for example, 20 seconds) in the first timer 23. If a new detection signal is output before the first predetermined time elapses after the detection signal is output (that is, within 20 seconds before the first timer 23 times out), the user is continuously seated. It is determined that there is a person and the seated state 100 is maintained. When a new detection signal is output, the state determination unit 25 sets the first predetermined time (20 seconds) in the first timer 23 again. On the other hand, the state determination unit 25 determines whether to leave the seat when the detection signal is not output continuously for the first predetermined time (20 seconds) after the previous detection signal is output (that is, when the first timer 23 times out). Transition to state 110.

  When the state determination unit 25 transitions to the absence determination state 110, first, the state determination unit 25 sets a second predetermined time (for example, 10 seconds) in the first timer 23. Then, after transitioning to the absence determination state 110, the state determination unit 25 leaves the seat when the detection signal is not output continuously for the second predetermined time (10 seconds) (that is, when the first timer 23 times out). Transition to state 120. On the other hand, when the detection signal is output before the second predetermined time has elapsed (within 10 seconds) after the transition to the absence determination state 110, the state determination unit 25 causes the first timer 23 to output a third predetermined time ( For example, 5 seconds) is set, and a fourth predetermined time (for example, 3 seconds) is set in the second timer 24. When the detection signal is output before the fourth predetermined time has elapsed (within 3 seconds), the state determination unit 25 sets the fourth predetermined time (3 seconds) in the second timer 24 again. On the other hand, when the detection signal is not output for the fourth predetermined time (3 seconds) (that is, when the second timer 24 times out), the state shifts to the away state 120 (see FIG. 7). In addition, the state determination unit 25, when the third predetermined time (5 seconds) has elapsed (that is, when the first timer 23 has timed out), if the second timer 24 has not timed out, that is, the third If the detection signal is repeatedly output at an interval shorter than the fourth predetermined time (3 seconds) until the predetermined time (5 seconds) elapses, the state shifts to the seated state 100 (see FIG. 8).

  When the detection signal is output when the state determination unit 25 is in the away state 120, the state determination unit 25 shifts to the seating determination state 130. On the other hand, when the detection signal is not output, the determination state unit 25 holds the away state 120 until the detection signal is output.

  When the state determination unit 25 shifts to the seating determination state 130, the state determination unit 25 sets a fifth predetermined time (for example, 5 seconds) in the first timer 23 and sets a second predetermined time (for example, 3 seconds) in the second timer 24. ) Is set. If the detection signal is output before the sixth predetermined time has elapsed (within 3 seconds), the state determination unit 25 sets the sixth predetermined time (3 seconds) in the second timer 24 again. On the other hand, when the detection signal is not output for the sixth predetermined time (3 seconds) (that is, when the second timer 24 times out), the state shifts to the away state 120 (see FIG. 7). In addition, the state determination unit 25, when the fifth predetermined time (5 seconds) has elapsed (that is, when the first timer 23 has timed out), if the second timer 24 has not timed out, that is, the fifth If the detection signal is repeatedly output at an interval shorter than the sixth predetermined time (3 seconds) until the predetermined time (5 seconds) elapses, the state shifts to the seating state 100 (see FIG. 8). The result (determination state) determined by the state determination unit 25 is output to the output unit 26.

  The output unit 26 outputs a signal indicating the presence or absence of a seated person and / or a signal indicating the above-described four determination states to, for example, an externally connected electronic device (not shown). That is, the output unit 26 functions as output means described in the claims.

  The switching unit 27 switches the amplification factor of the amplifying unit 13 according to the four determination states described above. More specifically, the switching unit 27 switches the amplification factor of the amplification unit 13 so as to be larger when in the seated state 100 than when in the away state 120. Further, the switching unit 27 sets the amplification factor of the amplification unit 13 between the amplification factor in the seating state 100 and the amplification factor in the separation state 120 when in the absence determination state 110 and the seating determination state 130. Switch to be. That is, the switching unit 27 functions as a switching unit described in the claims. By switching the amplification factor in this way, the detection sensitivity is set higher in the seated state 100 than in the away state 120. In the absence determination state 110 and the seat determination state 130, the detection sensitivity is set between the seating state 100 and the leaving state 120. Thus, in the seated state 100, it is possible to detect even a small movement that moves the head, for example, and in the away state 120, it is difficult to pick up noise.

  Further, instead of or in addition to switching the amplification factor of the amplification unit 13, the threshold value of the comparison unit 22 described above may be switched. More specifically, when the user is in the seated state 100, the threshold value of the comparison unit 22 is switched to be lower (closer to the steady-state output value) than in the seated state 120. Further, when in the absence determination state 110 and the seating determination state 130, the threshold value of the comparison unit 22 is switched between the threshold value in the seating state 100 and the threshold value in the separation state 120. By switching the threshold in this way, the detection sensitivity is set higher in the seated state 100 than in the away state 120. In the absence determination state 110 and the seat determination state 130, the detection sensitivity is set between the seating state 100 and the leaving state 120. When the threshold value of the comparison unit 22 is switched, an amplifier using, for example, an operational amplifier with a fixed amplification factor may be used as the amplification unit 13 and the switching unit 27 may be omitted.

  Next, the operation of the human body detection device 1 and the human body detection method will be described with reference to FIGS. Here, FIG. 3 is a flowchart showing a processing procedure of human body detection processing (seating state processing) in the seating state 100 by the human body detection device 1, and FIG. 4 is a human body detection processing (seating) in the absence determination state 110. It is a flowchart which shows the process sequence of a determination process. FIG. 5 is a flowchart showing a processing procedure of human body detection processing (seating state processing) in the away state 120, and FIG. 6 is a flowchart showing processing procedure of human body detection processing (seating determination processing) in the seating determination state 130. It is. FIG. 7 is a diagram (seating determination) for explaining the seating determination processing / seating determination processing, and FIG. 8 is a diagram for explaining the seating determination processing / seating determination processing by the human body detection device 1. It is a figure (seating determination). Each process is repeatedly executed in the signal processing unit 20 at a predetermined cycle.

  First, the human body detection process (seat state process) in the seat state 100 will be described with reference to FIG. First, in step S100, the threshold value of the comparison unit 22 is switched to a low level (that is, high sensitivity). Instead of or in addition to the switching of the threshold value of the comparison unit 22, switching may be performed so that the amplification factor of the amplifier 13 is increased.

  Next, in step S102, a first predetermined time (for example, 20 seconds) is set in the first timer 23. In the subsequent step S104, it is determined whether or not a detection signal has been output. If the detection signal is output, the process proceeds to step S102, and the first predetermined time (for example, 20 seconds) is set in the first timer 23 again. On the other hand, when the detection signal is not output, the process proceeds to step S106.

  In step S106, the value of the first timer 23 is decremented. Thereafter, in step S108, a determination is made as to whether or not the value of the first timer 23 has become zero (that is, whether or not the first timer 23 has timed out). Here, when the value of the first timer 23 is not zero (when the first timer 23 has not timed out), the process proceeds to step S104, and the processes after step S104 described above are executed again. The On the other hand, when the value of the first timer 23 becomes zero, that is, for example, when the detection signal is not output for 20 seconds and the first timer 23 times out, it is determined whether or not the seated person has left the seat. Shift to the absence determination state 110 to be performed.

  Next, the human body detection process (separation determination process) in the absence determination state 110 will be described with reference to FIG. First, in step S200, the threshold value of the comparison unit 22 is switched to an intermediate level (that is, intermediate sensitivity). Note that the amplification factor of the amplifier 13 may be switched to an intermediate level instead of or in addition to the switching of the threshold value of the comparison unit 22.

  Next, in step S202, a second predetermined time (for example, 10 seconds) is set in the first timer 23. In the subsequent step S204, it is determined whether or not a detection signal has been output. If a detection signal is output here, the process proceeds to step S210. On the other hand, when the detection signal is not output, the process proceeds to step S206.

  In step S206, the value of the first timer 23 is decremented. Thereafter, in step S208, a determination is made as to whether or not the value of the first timer 23 has become zero (that is, whether or not the first timer 23 has timed out). Here, when the value of the first timer 23 is not zero (when the first timer 23 has not timed out), the process proceeds to step S204, and the processes after step S204 described above are executed again. The On the other hand, when the value of the first timer 23 becomes zero, that is, when the first timer 23 times out without outputting a detection signal for 10 seconds, for example, it is determined that no one is seated and the person leaves the seat. Transition to state 120.

  When the detection signal is output before the second predetermined time (for example, 10 seconds) elapses, a third predetermined time (for example, 5 seconds) is set in the first timer 23 in step S210. In the subsequent step S212, a fourth predetermined time (for example, 3 seconds) is set in the second timer 24.

  Next, in step S214, a determination is made as to whether or not the value of the first timer 23 has become zero (that is, whether or not the first timer 23 has timed out). Here, when the value of the first timer 23 is not zero (when the first timer 23 has not timed out), the process proceeds to step S216. On the other hand, when the value of the first timer 23 becomes zero, that is, as shown in FIG. 8, the detection signal is repeatedly output at a time interval shorter than the fourth predetermined time (3 seconds). When the first timer 23 times out without the second timer 24 timing out, it is determined that there is a seated person, and the seating state 100 described above is entered.

  If the first timer 23 has not timed out, a determination is made in step S216 as to whether the value of the second timer 24 has become zero (that is, whether the second timer 24 has timed out). Here, when the value of the second timer 24 is not zero (when the second timer 24 has not timed out), the process proceeds to step S218. On the other hand, when the value of the second timer 24 becomes zero, that is, as shown in FIG. 7, when the detection signal is not output for the fourth predetermined time (3 seconds) and the second timer 24 times out, It is determined that no person is seated, and the state transitions to the away state 120.

  If neither the first timer 23 nor the second timer 24 has timed out, the first timer 23 is decremented in step S218, and the second timer 24 is decremented in step S220.

  Subsequently, in step S222, a determination is made as to whether a detection signal has been output. Here, when the detection signal is output, the process proceeds to step S212, and after the fourth predetermined time (for example, 3 seconds) is set again in the second timer 24, the process after step S214 described above is performed. Is executed again. On the other hand, when the detection signal is not output, the process proceeds to step S214, and the processes after step S214 described above are executed again.

  Next, the human body detection process (seating process) in the away state 120 will be described with reference to FIG. First, in step S300, the threshold value of the comparison unit 22 is switched to a high level (that is, low sensitivity). Note that the amplification factor of the amplifier 13 may be switched to a low level instead of or in addition to the switching of the threshold value of the comparison unit 22.

  Next, in step S302, a determination is made as to whether a detection signal has been output. Here, when the detection signal is output, the process proceeds to a seating determination state 130 in which it is determined whether or not a person is seated. On the other hand, when the detection signal is not output, this step is repeatedly executed until the detection signal is output.

  Next, the human body detection process (seat determination process) in the seat determination state 130 will be described with reference to FIG. First, in step S400, the threshold value of the comparison unit 22 is switched to an intermediate level (that is, intermediate sensitivity). Note that the amplification factor of the amplifier 13 may be switched to an intermediate level instead of or in addition to the switching of the threshold value of the comparison unit 22.

  Next, in step S <b> 402, a fifth predetermined time (for example, 5 seconds) is set in the first timer 23. In the subsequent step S404, a sixth predetermined time (for example, 3 seconds) is set in the second timer 24.

  Next, in step S406, it is determined whether or not the value of the first timer 23 has become zero (that is, whether or not the first timer 23 has timed out). Here, when the value of the first timer 23 is not zero (when the first timer 23 has not timed out), the process proceeds to step S408. On the other hand, when the value of the first timer 23 becomes zero, that is, as shown in FIG. 8, the detection signal is repeatedly output at a time interval shorter than the fourth predetermined time (3 seconds). When the first timer 23 times out without the second timer 24 timing out, it is determined that there is a seated person, and the seating state 100 described above is entered.

  If the first timer 23 has not timed out, a determination is made in step S408 as to whether or not the value of the second timer 24 has become zero (that is, whether or not the second timer 24 has timed out). Here, when the value of the second timer 24 is not zero (when the second timer 24 has not timed out), the process proceeds to step S410. On the other hand, when the value of the second timer 24 becomes zero, that is, as shown in FIG. 7, when the detection signal is not output for the sixth predetermined time (3 seconds) and the second timer 24 times out, It is determined that no person is seated, and the state transitions to the away state 120.

  If neither the first timer 23 nor the second timer 24 has timed out, the first timer 23 is decremented in step S410, and the second timer 24 is decremented in step S412.

  Subsequently, in step S414, a determination is made as to whether a detection signal has been output. If the detection signal is output, the process proceeds to step S404, and after the sixth predetermined time (for example, 3 seconds) is set again in the second timer 24, the processes after step S406 described above are performed. Is executed again. On the other hand, when the detection signal is not output, the process proceeds to step S406, and the processes after step S406 described above are executed again.

  According to this embodiment, every time a detection signal is output, the elapsed time since the detection signal is output is counted, and the detection signal is repeated at a time interval (for example, within 3 seconds) shorter than a predetermined time. If it is output, it is determined that there is a seated person. That is, when the output fluctuation of the infrared detector 10 (dual type pyroelectric infrared sensor 12) continues, it is determined that there is a person seated. Therefore, for example, it is possible to discriminate between a seated person and a person passing behind, and selectively detect the presence or absence of a seated person without detecting a person passing behind. In addition, according to this embodiment, the noise which generate | occur | produces by one shot can also be removed, Therefore The false detection by noise can also be reduced.

  More specifically, according to the present embodiment, in the seated state 100, the detection signal is not output continuously for the first predetermined time (for example, 20 seconds), and further, the second predetermined time (for example, 10 seconds). ) When the detection signal is not continuously output, it is determined that no one is seated. On the other hand, even if the detection signal is not output continuously for the first predetermined time (20 seconds), the detection signal is output before the second predetermined time (10 seconds) elapses thereafter. After the detection signal is output, until the third predetermined time (for example, 5 seconds) elapses, the detection signal is repeated at a time interval shorter than the fourth predetermined time (for example, 3 seconds). If it is output, it is determined that there is a seated person. That is, when the output fluctuation of the infrared detector 10 (dual type pyroelectric infrared sensor 12) continues for the third predetermined time (5 seconds), it is determined that there is a person seated. On the other hand, if the detection signal is not repeatedly output at a time interval shorter than the fourth predetermined time (3 seconds) until the third predetermined time (5 seconds) elapses, the user is seated. It is determined that there are no people. Therefore, it is possible to reliably determine whether there are no seated persons (whether they have left).

  In addition, according to the present embodiment, when a detection signal is output in the away state 120, the fifth predetermined time (for example, 5 seconds) elapses after the detection signal is output. When the detection signal is repeatedly output at a time interval shorter than a predetermined time 6 (for example, 3 seconds), it is determined that there is a seated person. That is, when the output fluctuation of the infrared detector 10 (dual type pyroelectric infrared sensor 12) continues for a fifth predetermined time (5 seconds), it is determined that there is a person seated. . On the other hand, if the detection signal is not repeatedly output at a time interval shorter than the sixth predetermined time (3 seconds) until the fifth predetermined time (5 seconds) elapses, the user is seated. It is determined that there are no people. Therefore, it is possible to reliably determine whether a person has entered and sat down from a state in which there is no seated person (separated state 120).

  Further, according to the present embodiment, only the determination result, that is, the presence or absence of a seated person is output. That is, even if there is a person who passes behind, it can be excluded. Therefore, for example, when it is configured to turn on / off the electric device according to the output determination result, it prevents the electric device from being turned on in an unnecessary situation and reducing the energy saving effect. It becomes possible to do.

  Further, according to the present embodiment, when in the seated state 100, the threshold value of the comparison unit 22 is made lower than that in the away state 120, and the detection sensitivity is increased. That is, by lowering the threshold value of the comparison unit 22 in the sitting state 100 than in the leaving state 120, the sensitivity is increased in the sitting state 100 so that small movements can be detected, while the sensitivity is decreased in the leaving state 120. Thus, the influence of noise can be reduced.

  Further, according to the present embodiment, the detection sensitivity can be increased by increasing the amplification factor of the amplifying unit 13 in the seated state 100 than in the away state 120. In this case, for example, in the seated state 100, by increasing the amplification factor compared to that in the seated state 120, the sensitivity is increased in the seated state 100 and small movements can be detected, while the sensitivity is decreased in the seated state 120. Thus, the influence of noise can be reduced.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the dual type pyroelectric infrared sensor 12 having two pyroelectric elements connected in series so that the polarities are reversed is used. However, the single type pyroelectric type having one pyroelectric element is used. An infrared sensor or a quad-type pyroelectric infrared sensor having four elements may be used.

  In addition, the values of the first to sixth predetermined times set in the first timer 23 and the second timer 24 described above are examples, and the present invention is not limited to the above-described embodiment. Depending on the situation, it can be set arbitrarily.

  In the above embodiment, when the detection signal is output by comparing the output signal from the infrared detector 10 with the threshold value, the comparison unit 22 realized by the CPU and software performs processing in software. The hardware signal may be processed by inputting an electric signal before A / D conversion to a comparator and comparing it with a threshold value.

  In the above-described embodiment, a signal indicating the presence / absence of a seated person and / or a signal indicating the four determination states described above is output to, for example, an externally connected electronic device. Therefore, for example, in the seating state 100 and the absence determination state 110, the power of the electric device is turned on, and in the leaving state 120 and the seating state 130, the human body detection device 1 is connected by turning off the power of the electric device. It is possible to reduce the power consumption of the electrical equipment. In the seating determination state 130, a fifth predetermined time (for example, 5 seconds) is required until the seating state 100 is determined. However, when the user wants to start the electrical device without delay when sitting, The power source of the electrical device may be turned on when the determination state 130 is entered. In this case, when it is determined that the user is in the away state 120 after that, the state is changed to the away state 120 and the power is turned off. Therefore, the power supply can be returned to an off state in a short time, and thus a low power consumption state can be maintained.

DESCRIPTION OF SYMBOLS 1 Human body detection apparatus 10 Infrared detector 11 Condensing part 12 Dual type pyroelectric infrared sensor 13 Amplifying part 14 Bandpass filter 20 Signal processing unit 21 A / D conversion part 22 Comparison part 23 1st timer 24 2nd timer 25 State determination Part 26 output part 27 switching part

Claims (11)

An infrared sensor that outputs an electrical signal corresponding to the amount of change in infrared;
Comparing means for outputting a detection signal when the electrical signal output from the infrared sensor exceeds a threshold value;
Time measuring means for measuring the time elapsed since the detection signal was output each time the detection signal is output;
Based on the elapsed time measured by the time measuring means, it is determined whether or not an event in which the detection signal is output at repeated time intervals shorter than a predetermined time has occurred, and the event has occurred repeatedly. And a determination means for determining that there is a person who stays continuously in the predetermined area when recognized,
In the state where it is determined that there is a person staying in the predetermined region, the determination unit continues for a second predetermined time when the detection signal is not output for a first predetermined time. When the detection signal is not output, it is determined that there is no person staying in the predetermined area , and the detection signal is output when the detection signal is output before the second predetermined time elapses. When it is recognized that an event in which the detection signal is output at a time interval shorter than the fourth predetermined time has occurred repeatedly until the third predetermined time elapses from If it is determined that there is a person staying in the area and the event has not occurred repeatedly until the third predetermined time has passed, no person remains in the predetermined area. characterized in that it is determined that the The human body sensing device to. In the state where it is determined that there is no person staying in the predetermined area, the determination unit outputs a fifth predetermined time from the time when the detection signal is output when the detection signal is output. Until it is determined that there is a person who remains in the predetermined area when it is recognized that the event in which the detection signal is output at repeated time intervals shorter than the sixth predetermined time has occurred. and, until the predetermined time of the fifth has elapsed, claim 1 in which the event when not occur repeatedly, and judging that there is no person who remains in the predetermined area The human body detection device described in 1. The human body detection device according to claim 2 , further comprising: an output unit that outputs a determination result by the determination unit. When the comparison means is in a state where it is determined that there is a person who remains in the predetermined area, the comparison means is in a state where it is determined that no person remains in the predetermined area. human body detection device according to any one of claims 1 to 3, characterized in that lower than when. An amplifier capable of varying an amplification factor and amplifying an electric signal output from the infrared sensor;
When it is determined that there is a person staying in the predetermined area, the amplification factor of the amplifier is more than when it is determined that there is no person staying in the predetermined area. human body detection device according to any one of claims 1 to 4, characterized in that also comprises a switching means for increasing. The infrared sensor is in any one of claims 1 to 5, characterized in that polarity is pyroelectric infrared sensor of a dual type having two pyroelectric elements connected in series such that the opposite The human body detection device described. A comparison step of outputting a detection signal when the electrical signal output from the infrared sensor that outputs an electrical signal corresponding to the amount of change in infrared exceeds a threshold;
Each time the detection signal is output, a time measuring step of measuring an elapsed time since the detection signal was output;
Based on the elapsed time measured in the timing step, it is determined whether or not the event in which the detection signal is output at repeated intervals shorter than a predetermined time has occurred, and it is recognized that the event has occurred repeatedly. And a determination step for determining that there is a person who stays continuously in the predetermined area,
In the determination step, in a state where it is determined that there is a person staying in the predetermined region, when the detection signal is not output continuously for a first predetermined time, the second predetermined time continues further. When the detection signal is not output, it is determined that there is no person staying in the predetermined area , and the detection signal is output when the detection signal is output before the second predetermined time elapses. When it is recognized that an event in which the detection signal is output at a time interval shorter than the fourth predetermined time has occurred repeatedly until the third predetermined time elapses from If it is determined that there is a person staying in the area and the event has not occurred repeatedly until the third predetermined time has passed, no person remains in the predetermined area. it is determined that Human body detection method according to claim. In the determination step, when it is determined that there is no person staying in the predetermined area, when the detection signal is output, a fifth predetermined time has elapsed since the detection signal was output. Until it is determined that there is a person who remains in the predetermined area when it is recognized that the event in which the detection signal is output at repeated time intervals shorter than the sixth predetermined time has occurred. and, until the predetermined time of the fifth has elapsed, claim 7, characterized in that to determine that if the event does not occur repeatedly, who remains in the predetermined area is not The human body detection method described in 1. The human body detection method according to claim 8 , further comprising an output step of outputting a determination result in the determination step. In the comparison step, when it is determined that there is a person staying in the predetermined area, the threshold value is in a state where it is determined that there is no person staying in the predetermined area. The human body detection method according to any one of claims 7 to 9 , wherein the human body detection method is set lower than the time. A person who stays in the predetermined area with an amplification factor of an amplifier that amplifies an electric signal output from the infrared sensor when it is determined that there is a person staying in the predetermined area. human body detection method according to any one of claims 7 to 10, characterized in that it comprises a switching step to be larger than when in the state it is determined that there is no.

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