JP7339010B2 - Approach detection device and approach detection system - Google Patents

Description

The present invention relates to a proximity detection device and a proximity detection system.

If a passerby opens the door without noticing a person on the other side of the door, the door may collide with the person. On the other hand, there is a device that prevents a collision when opening a door by detecting people on both sides of the door (see Patent Documents 1 and 2).

Japanese Unexamined Patent Application Publication No. 2016-142110 JP-A-2002-92754

In this type of device, it is necessary to notify the alarm device on the opposite side of the door of the detection result of the person detected by the sensor, so a means for communicating beyond the wall is required. As communication means, for example, a wireless LAN (Local Area Network) or a 3G (3rd Generation) communication device is used, but there are problems of increased power consumption and scale.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a small approach detection device and approach detection system with low power consumption.

In one aspect, the approach detection device includes a transmitter that transmits radio waves, a receiver that receives reflected waves of the radio waves, and a first detector that detects the approach of a first moving object based on the reflected waves. , in response to detection of the approach of the first moving body by the first detection unit, notification of the approach of the first moving body to another device that receives notification of the approach of the first moving body and controls an alarm . a control unit that modulates and transmits the radio wave to the transmitting unit so as to transmit the radio waves, a second detection unit that detects the modulated wave of the other device that notifies the approach of the second moving body to the other device , and the second 2 an alarm control unit for controlling the output of an alarm based on the detection result of the detection unit;

In one aspect, it has a first proximity detection device and a second proximity detection device, and the first proximity detection device includes a first transmitter that transmits a first radio wave and a reflected wave of the first radio wave. a first receiving unit for receiving; a first detecting unit for detecting the approach of the first moving object to the first proximity detection device based on the reflected wave of the first radio wave; 2. a second detection unit for detecting an approach of a moving object, and causing the first transmission unit to modulate the first radio wave into a first modulated wave when the first detection unit detects the approach of the first moving object. and a first alarm control unit that controls the output of an alarm based on the detection result of the second detection unit, and the second approach detection device transmits a second radio wave 2 transmitting unit, a second receiving unit for receiving the reflected wave of the second radio wave, and a second receiving unit for detecting the approach of the second moving object to the second approach detection device based on the reflected wave of the second radio wave 3 detection units, a fourth detection unit that detects the approach of the first moving body to the first approach detection device, and when the third detection unit detects the approach of the second moving body, the second A second control unit that modulates the second radio wave to a second modulated wave and transmits it to the transmission unit, and a second alarm control unit that controls the output of the alarm based on the detection result of the fourth detection unit , The second detection unit detects the approach of the second moving object in response to reception of the second modulated wave by the first reception unit, and the fourth detection unit detects the first detection by the second reception unit. The approach of the first moving body is detected in response to reception of the modulated wave.

ADVANTAGE OF THE INVENTION According to this invention, an approach detection apparatus and an approach detection system can be reduced in size, and power consumption can be reduced.

FIG. 1 is a diagram showing an operation example of the approach detection system. FIG. 2 is a configuration diagram showing an example of an approach detection system. FIG. 3(a) is a waveform diagram showing an example of the I component and Q component of an IF (Intermediate Frequency) signal, and FIG. 3(b) is a diagram showing an example of directivity of a transmitting antenna and a receiving antenna. . FIG. 4(a) is a waveform diagram showing an example of the modulated signal, and FIG. 4(b) is a waveform diagram showing another example of the modulated signal. FIG. 5 is a configuration diagram showing an example of an approach detection device. FIG. 6 is a flowchart illustrating an example of radio wave transmission processing. FIG. 7 is a flowchart showing an example of an alarm output process.

FIG. 1 is a diagram showing an operation example of the approach detection system. The proximity detection system includes proximity detection devices 1a, 1b respectively mounted on opposite sides of a wall 90 having a door 92 thereon. The approach detection devices 1a and 1b respectively transmit radio waves and detect the approach of people from the reflected waves.

In this example, the case where the person Ha is approaching the door 92 from the approach detection device 1a side and the person Hb is approaching the door 92 from the approach detection device 1b side will be described. Here, when the person Ha reaches the door 92 before the person Hb and pushes the door 92 open (see R), the door 92 and the person Hb may collide. In FIG. 1, door 92 in the open state is indicated by dotted lines.

The approach detection device 1a transmits radio waves Ws, and detects the approach of the person Ha to the door 92 by the reflected wave Wr of the radio waves Ws reflected by the person Ha. Here, the proximity detection device 1a uses the principle of the Doppler effect to detect the movement of the person Ha based on the frequencies of the transmitted radio waves Ws and the received reflected waves Wr.

When the approach detection device 1a detects the approach of the person Ha to the door 92, the approach detection device 1a notifies the approach to the other approach detection device 1b (see S). The proximity detection device 1b outputs an alarm upon receiving the notification from the proximity detection device 1a.

When the person Hb notices the alarm, the person Hb can recognize that the person Ha is on the other side of the door 92 and can stop in front of the door 92 . Therefore, even if the person Ha opens the door 92, the door 92 does not collide with the person Hb on the opposite side. Even when the person Hb arrives at the door 92 before the person Ha, the approach detection device 1b detects the approach of the person Hb and notifies the other approach detection device 1a, so that the approach detection device 1a outputs an alarm. Therefore, collision between the person Ha and the door 92 is prevented.

FIG. 2 is a configuration diagram showing an example of an approach detection system. The proximity detection devices 1 a and 1 b are examples of first and second proximity detection devices, and are provided on both sides of the wall 90 . The approach detection devices 1a and 1b detect the approach of the moving bodies 91a and 91b and notify the other approach detection devices 1b and 1a. The approach detection devices 1a and 1b output an alarm when receiving notification of the approach of the moving body from the other approach detection devices 1b and 1a. The moving bodies 91a and 91b are examples of first and second moving bodies. Hereinafter, when distinguishing between the approach detection devices 1a and 1b, a or b is added to the reference numerals of each element, and when common description is given, the reference numerals omitting a and b may be used generically.

Each approach detection device 1 has an MCU (Micro Control Unit) 10, an RF (Radio Frequency) module 11, a DIP switch (SW) 12, a transmitting antenna 13, a receiving antenna 14, and an alarm device 15, respectively.

The RF module 11 transmits the detected wave 84 through the transmitting antenna 13 and receives the reflected wave 85 through the receiving antenna 14 . The detection wave 84 is a component of the radio wave Ws radiated toward the moving object 91 such as the person H. As shown in FIG.

The detection wave 84 is, for example, a sinusoidal continuous wave (CW) having a frequency in the ISM (Industry Science and Medical) band (eg, 24 GHz band). The frequency is different from that of the detection wave 84b transmitted by the detection device 1b. Reflected wave 85 is generated when detected wave 84 is reflected by moving body 91 . At this time, since the frequencies of the detected waves 84a and 84b are different from each other, the frequencies of the reflected waves 85a and 85b are also different. Therefore, interference between the reflected waves 85a and 85b does not hinder the detection of the moving bodies 91a and 91b.

According to the principle of the Doppler effect, when the moving object 91 is approaching the approach detecting device 1, the frequency of the reflected wave 85 becomes higher than the frequency of the detected wave 84 as shown in the drawing, and the moving object 91 is detected from the approach detecting device 1. When moving away, the frequency of the reflected wave 85 will be lower than the frequency of the detected wave 84 . When the moving body 91 is stationary, the frequencies of the detected wave 84 and the reflected wave 85 are the same.

The RF module 11 generates a detection wave 84 based on a sine wave signal from a VCO (Voltage Controlled Oscillator). The RF module 11 mixes the RF signal obtained by detecting the reflected wave 85 and the sinusoidal signal of the VCO, generates an IF signal according to the frequency difference between the detected wave 84 and the reflected wave 85, and outputs the IF signal to the MCU10.

FIG. 3(a) is a waveform diagram showing an example of the I component Si and the Q component Sq of the IF signal. Reference numeral 82 denotes a waveform diagram when the moving body 91 is stopped or when there is no moving body 91, and reference numeral 83 denotes a waveform diagram when the moving body 91 is moving. In each waveform diagram, the horizontal axis indicates time and the vertical axis indicates voltage.

When the moving body 91 is stationary or when there is no moving body 91, the I component Si and the Q component Sq have flat waveforms. When the moving body 91 is moving, the I component Si and the Q component Sq are sine waves out of phase with each other. Note that the sine wave is an example, and the waveforms of the I component Si and the Q component Sq may have other shapes.

Referring to FIG. 2 again, the MCU 10a detects the approach of the moving body 91a from the phase relationship between the I component Si and the Q component Sq. When the MCU 10a detects the approach of the moving object 91a, the MCU 10a causes the RF module 11a to modulate the detection wave 84a. As a result, the approach detection device 1b notifies the other approach detection device 1b of the approach of the moving object 91a.

The transmitting antenna 13 and the receiving antenna 14 have directivity not only on the front side of the wall 90 but also on the back side. Therefore, part of the radio wave Ws radiated from the transmitting antenna 13 passes through the wall 90 . A transmitted wave 86 that has passed through the wall 90 is received by the receiving antenna 14 on the back side of the wall 90 .

FIG. 3B is a diagram showing an example of directivity of the transmitting antenna 13 and the receiving antenna 14. As shown in FIG. The transmitting antenna 13 and the receiving antenna 14 have directivity such that the main lobe 80 spreads in the direction of 0° and the back lobe 81 spreads in the direction of 180° with the point P as the center. Here, wall 90 extends in directions of 90° and 270°.

The transmitting antenna 13 is installed with the main lobe 80 directed toward the moving body 91 and the back lobe 81 directed toward the receiving antenna 14 on the back side of the wall 90 . Also, the receiving antenna 14 is installed with the main lobe 80 directed in the direction in which the reflected wave 85 arrives, and the back lobe 81 directed in the direction in which the transmitted wave 86 arrives from the transmitting antenna 13 on the back side of the wall 90 .

Referring to FIG. 2 again, the transmitting antenna 13a radiates the detection wave 84a, which is the main lobe 80, toward the moving object 91a, and transmits the transmitted wave 86a, which is the back lobe 81, toward the receiving antenna 14b on the back side of the wall 90. be radiated. The receiving antenna 14 b receives the transmitted wave 86 a through the back lobe 81 and the reflected wave 85 b through the main lobe 80 .

Further, the transmitting antenna 13b radiates a detection wave 84b, which is the main lobe 80, toward the moving body 91b, and a transmitted wave 86b, which is the back lobe 81, toward the receiving antenna 14a on the opposite side of the wall 90. FIG. The receiving antenna 14 a receives the transmitted wave 86 b through the back lobe 81 and the reflected wave 85 b through the main lobe 80 .

The RF module 11 detects the transmitted wave 86 to convert it into an electrical transmitted signal and outputs it to the MCU 10 . The MCU 10 determines whether or not the transmitted signal is a modulated signal, and causes the alarm device 15 to output an alarm when the transmitted signal is a modulated signal.

As described above, when the MCU 10a detects the approach of the moving body 91a, the MCU 10a causes the RF module 11a to modulate the radio wave Ws into a modulated wave. In this case, not only the detected wave 84a but also the transmitted wave 86a are modulated, so the MCU 10b on the back side of the wall 90 determines whether or not the transmitted signal is a modulated signal. Modulation schemes include, for example, the following OOK (On Off Keying) and PPM (Pulse Position Modulation).

FIG. 4(a) is a waveform diagram showing an example of a modulated signal. The modulation scheme in this example is OOK.

The detected wave 84 and the transmitted wave 86 before modulation are continuous sine waves, but the modulated waves, which are the detected wave 84 and the transmitted wave 86, are intermittent sine waves that are turned on and off at regular intervals. Therefore, the transmitted signal obtained from the transmitted wave 86 becomes a modulated signal that repeats logical values "1" and "0" at a constant cycle.

FIG. 4(b) is a waveform diagram showing another example of the modulated signal. The modulation scheme in this example is PPM.

A modulated wave obtained by modulating the detected wave 84 and the transmitted wave 86 becomes an intermittent sinusoidal wave that is turned on and off in a periodic predetermined pattern. Therefore, the transmitted signal obtained from the transmitted wave 86 becomes a modulated signal that repeats a predetermined pattern of logical values "1" and "0" at a constant period. Note that the type of modulation scheme (OOK, PPM, etc.) may be switched by the user, for example, by setting the SW12.

Referring to FIG. 2 again, the MCU 10 determines whether or not the transmitted signal is a modulated signal by, for example, matching the transmitted signal with a predetermined pattern. The MCU 10 controls the alarm device 15 to output an alarm when the transmitted signal is the modulated signal, and does not control the alarm devices 15a and 15b when the transmitted signal is not the modulated signal. The MCU 10 controls the alarm device 15 so as to stop outputting the alarm when, for example, a predetermined period of time elapses after the alarm is output.

The alarm 15 is, for example, a buzzer or an LED (Light Emitting Diode). The buzzer notifies the approach of the moving body 91 by sound, and the LED notifies the approach of the moving body 91 by light. Note that the MCU 10 may control the pattern of sound or light in accordance with the setting from the SW12.

The SW 12 is used by the user to make various settings for the proximity detection device 1 . The settings include, for example, a channel ID corresponding to the frequency of the radio wave Ws of the approach detection device 1, the priority of the alarm of the alarm device 15 (“1”: priority, “0”: non-priority), and the output of the alarm at the time of non-priority. There are availability information, an alarm delay time Td at the time of non-priority, a modulation period Tm of the radio wave Ws, an alarm pattern of the alarm device 15, and the like. Different channel IDs are set for the approach detection devices 1a and 1b, and different priorities are set for the alarm devices 15a and 15b.

The MCU 10 acquires settings from the SW 12 and sets them in the RF module 11 and the alarm device 15, for example, when the proximity detection device 1 is activated. Next, the details of the functional configuration of the detection device 1 will be described.

FIG. 5 is a configuration diagram showing an example of the approach detection device 1. As shown in FIG. The RF module 11 has a transmitter circuit 110 and a receiver circuit 111 . The transmission circuit 110 and the transmission antenna 13 are examples of first and second transmission units, and transmit radio waves Ws. The receiving circuit 111 and the receiving antenna 14 are examples of the first and second receiving units, and receive the radio wave Ws. The transmission circuit 110 and the reception circuit 111 are circuits configured by hardware such as ASIC (Application Specified Integrated Circuit).

The transmission circuit 110 has a VCO 112 that generates a sine wave signal and a modulator 113 that modulates the sine wave signal. VCO 112 changes the frequency of the sine wave signal according to the channel ID notified from MCU 10 . The modulator 113 starts or stops modulation processing according to on/off control of the MCU 10. A signal output from the modulator 113 is input to the transmitting antenna 13 and the receiving circuit 111. FIG. The transmitting antenna 13 transmits a sine wave signal as radio waves Ws. When the modulator 113 is performing modulation processing, a modulated wave is transmitted from the transmission antenna 13 .

Further, the receiving antenna 14 receives the reflected wave 85 and the radio wave Ws transmitted from the transmitting antennas 13 a and 13 b of the proximity detection device 1 on the back side of the wall 90 , that is, the transmitted wave 86 . The approach detection device 1 may have an additional receiving antenna on the back side of the wall 90 to receive the transmitted wave 86 .

The receiving circuit 111 has frequency filters 114 and 118 , a mixer 115 and detection circuits 116 and 117 . Frequency filters 114 and 118 filter RF signals input from receiving antenna 14 . The RF signal includes signal components of the reflected wave 85 and the transmitted wave 86 received by the receiving antenna 14 .

A transmission band corresponding to the frequency of the detected wave 84 is set in the frequency filter 114 according to the channel ID notified from the MCU 10 . Thereby, the frequency filter 114 transmits the signal component of the reflected wave 85 according to the channel ID notified from the MCU 10 and outputs the signal component to the mixer 115 . Therefore, the receiving circuit 111 can receive the reflected wave 85 of the detected wave 84 transmitted by the transmitting circuit 110 .

The mixer 115 mixes the sine wave signal from the transmission circuit 110 and the signal component of the reflected wave 85 and outputs the result to the detection circuit 116 . The detection circuit 116 detects the mixer signal input from the mixer 115 to generate an I component Si and a Q component Sq and outputs them to the MCU 10 .

Further, the frequency filter 114 is set with a transmission band corresponding to the frequency of the transmitted wave 86 according to the channel ID of the proximity detection device 1 on the back side of the wall 90 notified from the MCU 10 . Thereby, the frequency filter 118 transmits the signal component of the transmitted wave 86 and outputs it to the detection circuit 117 . The detection circuit 117 detects the signal input from the frequency filter 118 to generate a transmission signal Sn and outputs it to the MCU 10 .

The MCU 10 has an arithmetic processing circuit 100 and a memory 106 . The arithmetic processing circuit 100 is a processor that performs arithmetic processing according to a program, and the memory 106 stores programs and variables used by the arithmetic processing circuit 100 .

When the arithmetic processing circuit 100 reads a program from the memory 106, it forms a setting processing unit 101, a transmission control unit 102, an approach detection unit 103, a notification detection unit 104, and an alarm control unit 105 as functions.

The setting processing unit 101 acquires the setting of the SW 12 when the approach detection device 1 is activated. The setting processing unit 101 sets channel IDs in the transmission circuit 110 and the reception circuit 111 , and sets priority, alarm output enable/disable information, and delay time Td in the alarm control unit 105 . The setting processing unit 101 also sets the modulation period Tm of the radio wave Ws to the transmission control unit 102 . The user sets the SWs 12a and 12b so that the channel IDs of the approach detection devices 1a and 1b and the priorities of the alarm devices 15a and 15b are different.

The approach detection unit 103 is an example of the second and fourth detection units, and detects the approach of the moving object 91 based on the reflected wave 85 of the radio wave Ws. The approach detection unit 103 detects the approach of the moving body 91 from the phase relationship between the I component Si and the Q component Sq based on the principle of the Doppler effect. When the approach detection unit 103 determines that the moving object 91 is approaching, the approach detection unit 103 notifies the transmission control unit 102 of detection of approach.

The transmission control unit 102 is an example of a control unit, and when the approach detection unit 103 detects the approach of the moving body 91, the transmission circuit 110 transmits the radio wave Ws as shown in FIG. 4(a) or FIG. 4(b). It modulates into a modulated wave like When the approach detector 103 notifies the transmission controller 102 of the detection of the approach of the moving body 91, the transmission controller 102 controls the modulator 113 to be in the ON state.

As a result, the modulator 113 starts modulating the sine wave signal of the VCO 112, so that the radio waves Ws are modulated into modulated waves. By modulating the radio waves Ws, the proximity detection device 1 can notify the proximity detection device 1 on the back side of the wall 90 of the approach of the moving body 91 to the device using modulated waves.

In this way, the approach detection device 1 does not use a wireless LAN or 3G communication device for notification of approach, and does not require large-scale electrical components with high power consumption, so it can be reduced in power consumption and size. is.

Further, after receiving the notification from the approach detection section 103, the transmission control section 102 controls the modulator 113 to be in an OFF state when the modulation period Tm has elapsed. This causes modulator 113 to stop modulating the signal from VCO 112 .

In this manner, the transmission control unit 102 causes the transmission circuit 110 to modulate the radio wave Ws for the modulation period Tm. Therefore, the proximity detection device 1 can automatically stop detecting the approach of the moving object 91 to the proximity detection device 1 on the back side of the wall 90 without the user's operation.

The notification detection unit 104 is an example of the second and fourth detection units, and detects the approach of the moving body 91 to the proximity detection device 1 on the back side of the wall 90 in response to reception of the modulated wave by the reception circuit 111 . . The notification detection unit 104 collates the transmitted signal Sn with the pattern of the modulated signal as shown in FIG. 4(a) or 4(b). If the transmitted signal Sn matches the pattern as a result of collation, the notification detection unit 104 recognizes that the transmitted signal Sn is a modulated signal for notifying the approach of the moving body 91 , and It is determined that the moving body 91 is approaching.

Therefore, the approach detection device 1 can detect the approach of the moving body 91 on the back side of the wall 90, which cannot be detected by the radio waves Ws of the device itself. The notification detection unit 104 notifies the alarm control unit 105 of detection of the modulated signal.

The alarm controller 105 is an example of the first and second alarm controllers 105 and controls the output of the alarm by the alarm device 15 . The alarm device 15 outputs an alarm indicating the approach of the moving object 91 to the approach detection device 1 on the back side of the wall 90 under the control of the alarm control unit 105 .

Also, the approach detection unit 103 notifies the alarm control unit 105 of the approach of the moving object 91 . When the approach of the moving bodies 91a and 91b is detected at the same time, the alarm control unit 105 delays or cancels the alarm by the alarm device 15 of its own device according to the priority. Since the alarm control units 105 of the approach detection devices 1a and 1b have different priorities, the alarm control unit 105 having a higher priority causes the alarm device 15 of its own device to output an alarm.

On the other hand, the alarm control unit 105 with a low priority causes the alarm device 15 of its own device to delay the output of the alarm from the other alarm device 15 by the delay time Td, or stop the output of the alarm. Here, the alarm control unit 105 with a low priority delays the output of the alarm when the alarm output propriety information indicates "possible", and stops outputting the alarm when the alarm output propriety information indicates "impossible". do.

In this way, when the notification detection units 104 of the approach detection devices 1a and 1b respectively detect the approach of the moving bodies 91b and 91a, the one with the lower priority among the alarm control units 105 of the approach detection devices 1a and 1b The alarm control unit 105 delays or cancels the alarm. Therefore, in the example of FIG. 1, for example, the persons Ha and Hb are prevented from stopping across the door 92 due to receiving alarms from the approach detection devices 1a and 1b at the same time, and thus giving way to each other.

Further, for example, if the wall surface on which the proximity detection device 1a is installed is the wall surface on the side that pushes the door 92 open, the priority of the alarm control unit 105 of the proximity detection device 1a is set higher than that of the other alarm control unit 105. good too. In this case, the person Ha receives a warning from the approach detection device 1a and carefully opens the door 92, so that the collision between the pushed open door 92 and the person Hb can be effectively prevented.

Next, processing of the approach detection devices 1a and 1b will be described.

FIG. 6 is a flow chart showing an example of transmission processing of the radio wave Ws. This processing is repeatedly executed, for example, at a constant cycle. The processing performed by the approach detection device 1a will be described below, but the approach detection device 1b also performs the same processing.

The transmission circuit 110 transmits radio waves Ws from the transmission antenna 13a (St1). The approach detection unit 103 determines whether the moving object 91a is approaching the approach detection device 1a from the phase relationship between the I component Si and the Q component Sq obtained from the reflected wave 85a of the radio wave Ws (St2). If the moving body 91a is not approaching (No in St2), the process ends.

If the moving object 91a is approaching (Yes in St2), the transmission control unit 102 turns on the modulator 113 (St3). Thereby, the radio wave Ws is modulated. At this time, the radio wave Ws is modulated so as to be distinguishable from the detection of the moving object 91 . Next, after waiting for the modulation period Tm (St4), the transmission control section 102 controls the modulator 113 to be turned off (St5). Thereby, the modulation processing of the radio waves Ws is stopped. Thus, the transmission processing of the radio wave Ws is executed.

FIG. 7 is a flowchart showing an example of an alarm output process. This processing is repeatedly executed, for example, at a constant cycle.

The notification detection unit 104 determines whether or not the transmission signal Sn from the receiving circuit 111 is a modulated signal by pattern collation (St11). If the transmitted signal Sn is not a modulated signal (No in St11), the process ends.

Further, when the transmission signal Sn is a modulated signal (Yes in St11), the notification detection unit 104 determines that the moving body 91b is approaching the approach detection device 1b on the back side of the wall 90, and moves to the own device. Whether or not the body 91a is approaching is determined based on the notification from the approach detection unit 103 (St12). Thereby, the approach detection device 1a determines whether or not the moving bodies 91a and 91b are approaching the approach detection devices 1a and 1b at the same time.

If the moving body 91a is not approaching the device itself (No in St12), the alarm control unit 105 causes the alarm device 15a to start outputting an alarm (St13). Next, after waiting for a predetermined time (St14), the alarm control unit 105 causes the alarm device 15a to stop outputting an alarm (St15).

Further, when the moving body 91a is approaching the device itself (Yes in St12), the alarm control unit 105 determines that the moving bodies 91a and 91b are approaching the approach detection devices 1a and 1b at the same time. 15a is "1" (high priority) or not (St16). If the priority is "1" (Yes in St16), each process after St13 is executed.

Further, when the priority is "0" (low priority) (No in St16), the alarm control unit 105 determines whether or not the alarm propriety information indicates "possible" (St17). When the alarm propriety information indicates "impossible" (No in St17), the alarm control unit 105 terminates the process without causing the alarm device 15a to output an alarm. That is, the alarm control unit 105 stops outputting the alarm.

Therefore, in the example of FIG. 1, one of the persons Ha and Hb on both sides of the door 92, who is on the side of the high-priority alarm devices 15a and 15b, does not notice the presence of the other. Therefore, it is possible to prevent the persons Ha and Hb from stopping across the door 92 due to receiving alarms from the approach detection devices 1a and 1b at the same time, and thus giving way to each other.

Further, when the alarm availability information indicates "Yes" (Yes in St17), the alarm control unit 105 waits for the delay time Td (St18), and then causes the alarm device 15a to start outputting an alarm (St13). As a result, the low-priority alarm device 15a outputs an alarm with a delay of at least the delay time Td from the high-priority alarm device 15b.

Therefore, in the example of FIG. 1, it is possible to shift the timing at which the persons Ha and Hb on both sides of the door 92 become aware of each other's existence. Therefore, it is possible to prevent the persons Ha and Hb from stopping across the door 92 due to receiving alarms from the approach detection devices 1a and 1b at the same time, and thus giving way to each other. After that, each process after St14 is executed. Thus, the alarm output processing is executed.

As described above, the approach detection device 1a transmits the radio wave Ws and detects the approach of the moving body 91a to the device by the reflected wave 85a. When detecting the approach of the moving body 91a, the approach detecting device 1a can notify the other approach detecting device 1a of the approach of the moving body 91a by modulating the radio wave Ws.

For this reason, the approach detection device 1 does not use a wireless LAN or 3G communication device for notification of approach, and does not require large-scale electrical components with high power consumption, so that low power consumption and miniaturization are possible. be.

The embodiments described above are examples of preferred implementations of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

1a, 1b approach detection device 10a, 10b MCU
11a, 11b RF modules 13a, 13b transmission antennas 14a, 14b reception antennas 91a, 91b moving body 102 transmission control unit 103 approach detection unit 104 notification detection unit 105 alarm control unit 110 transmission circuit 111 reception circuit

Claims (4)

a transmitter that transmits radio waves;
a receiving unit that receives the reflected wave of the radio wave;
a first detection unit that detects the approach of the first moving body based on the reflected wave;
In response to detection of the approach of the first moving body by the first detection unit, the approach of the first moving body is notified to another device that receives the notification of the approach of the first moving body and controls the alarm. a control unit that causes the transmission unit to modulate and transmit the radio wave as
a second detection unit that detects a modulated wave of the other device that notifies the approach of the second moving body to the other device ;
and an alarm control unit that controls an output of an alarm based on the detection result of the second detection unit. Having a first proximity detection device and a second proximity detection device,
The first proximity detection device is
a first transmission unit that transmits a first radio wave;
a first receiver that receives the reflected wave of the first radio wave;
a first detection unit that detects an approach of the first moving body to the first approach detection device based on the reflected wave of the first radio wave;
a second detection unit that detects an approach of a second moving body to the second approach detection device;
a first control unit that modulates the first radio wave into a first modulated wave and transmits the first radio wave to the first transmission unit when the first detection unit detects the approach of the first moving body;
a first alarm control unit that controls the output of an alarm based on the detection result of the second detection unit;
The second proximity detection device,
a second transmitter that transmits a second radio wave;
a second receiver that receives the reflected wave of the second radio wave;
a third detection unit that detects the approach of the second moving body to the second approach detection device based on the reflected wave of the second radio wave;
a fourth detection unit that detects an approach of the first moving body to the first approach detection device;
a second control unit that modulates the second radio wave into a second modulated wave and transmits the second radio wave to the second transmission unit when the third detection unit detects the approach of the second moving object;
a second alarm control unit that controls the output of an alarm based on the detection result of the fourth detection unit;
The second detection unit detects the approach of the second moving object in response to reception of the second modulated wave by the first reception unit,
The approach detection system, wherein the fourth detection unit detects the approach of the first moving object in response to reception of the first modulated wave by the second reception unit. Different priorities are set for the first alarm control unit and the second alarm control unit,
When the second detection unit and the fourth detection unit detect the approach of the second moving body and the first moving body, respectively, the priority of the first alarm control unit and the second alarm control unit is 3. The proximity detection system of claim 2, wherein the lower alarm control delays or cancels the alarm. The first proximity detection device is provided on one side of the door,
4. The approach detection system according to claim 2, wherein said second approach detection device is provided on the other side of said door.

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