JP6445812B2 - Approach detection system - Google Patents

Description

  The present invention relates to an approach detection system that detects an approach between a mobile device and a worker and outputs an approach warning at a work site where mobile devices such as a forklift and a bulldozer come and go.

  As such an approach detection system, a system using an induction magnetic field (electromagnetic induction wave) and a radio wave is known. For example, in Patent Document 1, when a slave unit carried by an operator receives an induction magnetic field from a mobile device, the slave unit (radio wave transmission unit) transmits a radio wave, and the mobile unit (radio wave reception unit) receives the radio wave. Then, an approach detection system that outputs an alarm is disclosed. In addition, in the patent document 2, the inventors of the present application disclosed an alarm level according to the distance between the distance detection control device (radio wave receiving means) attached to the mobile device side and the RFID tag (radio wave sending means) attached to the worker side. An approach detection system has been disclosed in which the distance can be set on the mobile device side.

  However, in the conventional approach detection system, the worker is attached to the worker side even if the worker is in a safe area that is secured by a wall, a fence, or a line drawn on the floor. When the mobile device approaches the range where the radio wave transmitted from the radio wave transmitting means reaches, an approach warning is output. The approach warning at this time is unnecessary, and it is desired that an unnecessary approach warning is not output.

  Therefore, in order to prevent an unnecessary approach warning from being output when the worker is in the safe area, it is conceivable that the radio wave transmitting means is turned off when the worker enters the safe area. However, there is a risk that the operator forgets to return the radio wave transmission means to the ON state when leaving the safe area. If it is forgotten to return the radio wave transmission means to the on state, the approach warning is not output when necessary outside the safe area, and the safety of the worker cannot be ensured.

JP-A-7-168985 JP2013-142675A

  The problem to be solved by the present invention is to prevent unnecessary access warnings from being output when an operator is in a safe area, and to reliably output an access warning when necessary outside the safe area. It is to provide a proximity detection system.

According to one aspect of the present invention, the radio wave receiving means attached to the mobile device side receives radio waves transmitted from the radio wave sending means attached to the worker side, so that the mobile device and the worker can approach each other. In the approach detection system that detects an alarm and outputs an approach warning, a radio wave transmission control means including a radio wave stop operation unit is disposed at an entrance / exit of a safe area where the safety of the worker is ensured. An on-control signal that normally turns on the radio wave transmitting means is transmitted, and when the radio wave stop operation unit is operated, an off control signal that turns off the radio wave transmitting means is transmitted for a predetermined time thereafter , An approach detection system is provided in which the control signal and the off-control signal are transmitted so as to cover only a range covering an area where an operator passes in the entrance / exit part .

  In the present invention, when the radio wave transmitting means receives the off-control signal, it can be set so as to be insensitive to the on-control signal for a predetermined time thereafter. In addition, the reach ranges of the ON control signal and the OFF control signal and the predetermined time can be made variable by setting of the radio wave receiving means or the radio wave transmitting means. Further, in the present invention, the on control signal and the off control signal transmitted by the radio wave transmission control means can be induced magnetic field signals. In this case, the radio wave transmission means attached to the operator side converts the induced magnetic field signal into the induced magnetic field signal. It may have means for detecting.

  According to the approach detection system of the present invention, when the operator operates the radio wave stop operation unit of the radio wave transmission control unit when entering the safety zone from the entrance / exit part, the radio wave transmission unit is turned off. Therefore, it is possible to prevent an unnecessary approach warning from being output when the worker is in the safe area.

  On the other hand, the radio wave transmission control means is always set to transmit an on control signal for turning on the radio wave transmission means, and after a predetermined time has elapsed after the radio wave stop operation unit is operated, the on control signal is again transmitted. send. For this reason, when the worker leaves the safe area from the entrance / exit, the radio wave transmitting means automatically returns to the on state. Therefore, an approach warning is reliably output when necessary outside the safe area.

1 is a conceptual system configuration diagram of an approach detection system according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a specific configuration example of a radio wave transmission unit and a radio wave reception unit illustrated in FIG. 1.

  Hereinafter, embodiments of the present invention will be described based on examples shown in the drawings.

  FIG. 1 is a conceptual system configuration diagram of an approach detection system according to an embodiment of the present invention. The approach detection system shown in the figure includes a radio wave transmission means 20 attached to a worker 10 working at a work site, a radio wave reception means 40 attached to a mobile device 30 such as a forklift that travels around the work site, and a work site. It comprises radio wave transmission control means 60 arranged at the entrance / exit part 51 of the safety zone 50 inside.

  FIG. 2 is a block diagram illustrating a specific configuration example of the radio wave transmission unit 20 and the radio wave reception unit 40. The radio wave transmission means 20 shown in the figure is composed of an RFID tag with a magnetic field detection function, and includes a magnetic field sensor unit 21, a radio wave transmission unit 22, and a battery 23. The radio wave receiving means 40 transmits an induction magnetic field to the radio wave transmitting means 20 (RFID tag with a magnetic field detection function) and receives a radio wave transmitted from the radio wave transmitting means 20, so that the operator 10 (the radio wave transmitting means 20 ) And the mobile device 30 (the radio wave receiving means 40) are detected and an approach warning is output, which can be said to be a control device of the approach detection system. Specifically, the radio wave reception means 40 includes an induction magnetic field transmission unit 41, a radio wave reception unit 42, an alarm output unit 43, and a control unit 44 that controls them. The radio wave receiver 40 includes a voltage converter 45 that converts an external power source into a DC voltage (for example, 12 V) suitable for operation of the radio wave receiver 40.

  First, the basic operation of the proximity detection system according to the present embodiment will be described. The radio wave receiving means 40 transmits an induction magnetic field having a long waveband frequency (for example, 125 kHz) from the induction magnetic field transmission unit 41. And if the magnetic field sensor part 21 of the electromagnetic wave transmission means 20 detects an induction magnetic field, the electromagnetic wave transmission part 22 will transmit a magnetic field detection electromagnetic wave (UHF charged wave). When the radio wave receiving unit 42 of the radio wave receiving means 40 receives this magnetic field detection radio wave, the alarm output unit 43 outputs an approach alarm. The operation of each part of these radio wave receiving means 40 is controlled by the control unit 44. The reach of the induction magnetic field is about 5 m, and the reach of the magnetic field detection radio wave is about 20 to 100 m.

  Here, in the above-described basic operation, even if the worker 10 is in a safe area 50 that is partitioned and secured by a wall or the like, it is transmitted from the radio wave transmitting means 20 attached to the worker 10. When the mobile device 30 (radio wave receiving means 40) approaches a range where a radio wave (magnetic field detection radio wave) reaches, an approach warning is output. At this time, an approach warning is unnecessary. Therefore, in the present invention, the radio wave transmission control means 60 is installed at the entrance / exit part 51 of the safety area 50 so that an unnecessary approach warning is not output when the worker 10 is in the safety area 50.

  The radio wave transmission control means 60 includes a radio wave stop operation unit 61. The radio wave stopping operation unit 61 can be configured by a push button, for example. The radio wave transmission control unit 60 normally transmits an on control signal for turning on the radio wave transmission unit 20, and when the radio wave stop operation unit 61 is operated, the radio wave transmission control unit 60 turns off the radio wave transmission unit for a predetermined time thereafter. Send a signal. These ON control signals and OFF control signals are transmitted so as to cover a range that covers the area where the operator 10 passes in the entrance / exit part 51, for example, as indicated by a broken line range in FIG. The reach ranges of the ON control signal and the OFF control signal and the length of the predetermined time described above are variable. That is, these can be appropriately changed according to the setting of the radio wave transmission control means 60 according to the structure of the entrance / exit part 51 and the like. For example, the reach range of the ON control signal and the OFF control signal is set to a range with a radius of about 2 m centering on the radio wave transmission control means 60, and the predetermined time is set to about 2 seconds.

  Next, the operation of the approach detection system according to this embodiment using this radio wave transmission control means 60 will be described.

  When the worker 10 enters the safe area 50, the operator 10 operates the radio wave stop operation unit 61 of the radio wave transmission control means 60 installed at the entrance / exit unit 51. Then, the radio wave transmission control unit 60 transmits an off control signal, and the radio wave transmission unit 20 attached to the worker 10 is turned off. When the predetermined time elapses, the radio wave transmission control means 60 transmits the ON control signal again. However, when the worker 10 enters the main body region of the safety area 50 where the ON control signal does not reach within the predetermined time, the worker 10 Since the ON control signal does not reach the radio wave transmitting means 20 attached to the, the OFF state is maintained. In this case, the predetermined time described above may be set so as to match the time required for the operator to reach the main body region of the safe area 50 where the ON control signal does not reach.

  As described above, while the worker 10 is in the main body region of the safety area 50, an unnecessary approach warning is not output even if the mobile device 30 approaches.

  On the other hand, when the worker 10 leaves the safe area 50, the radio wave transmission means 20 attached to the worker 10 when passing through the entrance / exit 51 is an on-control signal transmitted from the radio wave transmission control means 60. Automatically returns to the on state. Accordingly, an approach warning is reliably output outside the safety zone 50 when necessary.

  In the present embodiment, the ON control signal and the OFF control signal transmitted by the radio wave transmission control means 60 are induction magnetic field signals, and these induction magnetic field signals are detected by the magnetic field sensor unit 21 (the induction magnetic field signal) of the radio wave transmission means 20. ) Is detected, the radio wave transmitting means 20 is turned on or off as described above.

  In the above embodiment, in order to prevent the radio wave transmission means 20 that has been turned off at the entrance / exit 51 of the safety zone 50 from immediately returning to the on state, the radio wave transmission control means 60 transmits the off control signal for a predetermined time ( Hereinafter, the “first predetermined time” is set so as to correspond to the time until the operator reaches the main body region of the safety area 50 where the ON control signal does not reach as described above. The predetermined time is not necessarily set in this way. That is, when the radio wave transmitting means 20 attached to the worker 10 receives the off control signal, the predetermined time (hereinafter referred to as “second predetermined time”) is insensitive to the on control signal thereafter. If set, it is possible to prevent the radio wave transmission means 20 that has been turned off at the entrance / exit part 51 of the safe area 50 from immediately returning to the on state, as in the embodiment. In this case, the first predetermined time can be set shorter than in the case of the embodiment. For example, the first control time can be set so that the ON control signal is transmitted immediately after the OFF control signal is transmitted. The second predetermined time may be set to a length comparable to the first predetermined time in the case of the embodiment, and can be appropriately changed (variable) by setting of the radio wave transmission means 20.

  In the embodiment, an RFID tag with a magnetic field detection function, that is, an RFID tag that transmits a magnetic field detection radio wave (radio wave) when an induction magnetic field is detected is used as the radio wave transmission means 20, but it is in an on state regardless of the induction magnetic field. In this case, an RFID tag that always emits radio waves can be used. In short, any radio wave transmitting means for transmitting radio waves having a predetermined reachable range can be used. Further, the radio wave receiving means 40 is not limited to the configuration example of FIG. 2, and by receiving the radio wave transmitted from the radio wave transmitting means, it is possible to detect the approach between the mobile device and the worker and output an approach alarm. Any material can be used.

  Furthermore, although the entrance / exit part 51 of the safe area 50 was provided in two places in the Example, the entrance / exit part 51 may be one place and may be three or more places. In either case, if the radio wave transmission control means 60 is installed in each entrance / exit part 51, the same operational effects as in the embodiment can be obtained. It will be apparent to those skilled in the art that other various modifications are possible.

10 Worker 20 Radio wave transmission means (RFID tag with magnetic field detection function)
DESCRIPTION OF SYMBOLS 21 Magnetic field sensor part 22 Radio wave transmission part 23 Battery 30 Mobile device 40 Radio wave receiving means (control apparatus)
DESCRIPTION OF SYMBOLS 41 Guide magnetic field transmission part 42 Radio wave reception part 43 Alarm output part 44 Control part 45 Voltage conversion part 50 Safety area 51 Entrance / exit part 60 Radio wave transmission control means 61 Radio wave stop operation part

Claims (4)

When the radio wave receiving means attached to the mobile device receives the radio wave transmitted from the radio wave sending means attached to the worker side, it detects the approach between the mobile device and the worker and outputs an approach warning. In the proximity detection system,
A radio wave transmission control means equipped with a radio wave stop operation part is arranged at the entrance / exit part of the safe area where the safety of the worker is secured,
The radio wave transmission control means always transmits an on control signal for turning on the radio wave transmission means, and an off control signal for turning off the radio wave transmission means for a predetermined time after the radio wave stop operation unit is operated. It originated the,
The proximity detection system according to claim 1, wherein the on control signal and the off control signal are transmitted so as to cover only an area covering an area where an operator passes in the entrance / exit part .   The approach detection system according to claim 1, wherein the radio wave transmission means is insensitive to the on control signal for a predetermined time after receiving the off control signal.   The approach detection system according to claim 1 or 2, wherein reach ranges of the ON control signal and the OFF control signal and the predetermined time are variable.   The on-control signal and the off-control signal transmitted by the radio wave transmission control means are induction magnetic field signals, and the radio wave transmission means attached to the worker side has means for detecting the induction magnetic field signal. An approach detection system according to any one of the above.

Images