Approach Warning System

Abstract

To prevent an unnecessary approach warning from being outputted in an approach warning system which detects an approach between vehicles and outputs the approach warning.SOLUTION: In an approach warning system which detects an approach between vehicles 1a and 1b and outputs an approach warning, detectors 2a and 2b and tags 3a and 3b are installed in the vehicles 1a and 1b, respectively. Device ID information of the detectors similarly installed in the vehicles in which the tags 3a and 3b are installed is registered as self device ID information in tag control units of the tags 3a and 3b. Only in a case where a magnetic field sensor unit detects an induction magnetic field including the self device ID information and detects an induction magnetic field including device ID information other than the self device ID information, the tag control unit transmits a magnetic field detection radio wave from a radio wave transmission unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a proximity warning system that detects the proximity of vehicles, such as forklifts and bulldozers, at a work site and outputs a proximity warning. [Background technology]

[0002] As such an approach warning system, the applicant of the present application has disclosed a system including a distance detection control device and an RFID tag with a magnetic field detection function in Patent Document 1. As an application of the system of Patent Document 1, the applicant of the present application has also created a prototype approach warning system in which a distance detection control device and an RFID tag with a magnetic field detection function are installed in each vehicle, and an approach warning is output upon detection of vehicles approaching each other.

[0003] In this prototype approach warning system, the distance detection control device operates in conjunction with the on / off state of the vehicle's engine, but the RFID tag with magnetic field detection function is battery-powered and not linked to the on / off state of the vehicle's engine. In other words, the RFID tag with magnetic field detection function continues to operate even when the vehicle is stopped and the engine is off. Therefore, when another vehicle approaches the stopped vehicle, the RFID tag with magnetic field detection function installed in the stopped vehicle reacts, causing the distance detection control device installed in the other vehicle to output an unnecessary approach warning. In other words, since the risk of another vehicle approaching the stopped vehicle is low, there is no need to output an approach warning. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-142675 A (Patent No. 583577 A) Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to prevent unnecessary output of an approach warning in an approach warning system that detects the approach of vehicles and outputs an approach warning. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided the following proximity warning system. An approach warning system that detects the approach of vehicles and outputs an approach warning, The system includes a distance detection control device and an RFID tag with a magnetic field detection function, which are installed in each vehicle. The distance detection control device includes a magnetic field transmission unit that transmits an induction magnetic field including device ID information of the distance detection control device, a radio wave reception unit, a device alarm unit that outputs the proximity alarm, and a device control unit that controls these units; The RFID tag with magnetic field detection function includes a magnetic field sensor unit that detects the induced magnetic field transmitted from the magnetic field transmitter unit, a radio wave transmitter unit that transmits a magnetic field detection radio wave when the magnetic field sensor unit detects the induced magnetic field, and a tag controller that controls these units; The tag control unit has registered therein, as its own device ID information, device ID information of the distance detection control device that is also installed in the vehicle in which the RFID tag with magnetic field detection function is installed, The tag control unit causes the radio wave transmitter to transmit the magnetic field detection radio wave only when the magnetic field sensor unit detects an induced magnetic field including the device's own ID information and also detects an induced magnetic field including device ID information other than the device's own ID information.

[0007] According to another aspect of the present invention, there is provided a proximity warning system. An approach warning system that detects the approach of vehicles and outputs an approach warning, The system includes a distance detection control device and an RFID tag with a magnetic field detection function, which are installed in each vehicle. The distance detection control device includes a magnetic field transmission unit that transmits an induction magnetic field including device ID information of the distance detection control device, a radio wave reception unit, a device alarm unit that outputs the proximity alarm, and a device control unit that controls these units; The RFID tag with magnetic field detection function includes a magnetic field sensor unit that detects the induced magnetic field transmitted from the magnetic field transmitter unit, a radio wave transmitter unit that transmits a magnetic field detection radio wave including tag ID information of the RFID tag with magnetic field detection function, the device ID information, and magnetic field strength information when the magnetic field sensor unit detects the induced magnetic field, and a tag controller that controls these units; The tag control unit has registered therein, as its own device ID information, device ID information of the distance detection control device that is also installed in the vehicle in which the RFID tag with magnetic field detection function is installed, the tag control unit, when the magnetic field sensor unit detects only the induction magnetic field including the own device ID information, adds alarm non-output information to the magnetic field detection radio wave output from the radio wave transmitter unit to prevent the device alarm unit from outputting the proximity alarm; Furthermore, the tag control unit, when the magnetic field sensor unit detects an induced magnetic field including the self-device ID information and also detects an induced magnetic field including device ID information other than the self-device ID information, causes the radio wave transmitting unit to transmit the magnetic field detection radio wave, an approach warning system. [Effects of the Invention]

[0008] According to the present invention, in a proximity warning system that detects the proximity of vehicles and outputs a proximity warning, it is possible to prevent unnecessary proximity warnings from being output. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a system configuration diagram of an approach warning system according to an embodiment of the present invention; [Figure 2] 2 is a block diagram showing the configuration of a distance detection control device and an RFID tag with a magnetic field detection function in the proximity warning system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0010] Fig. 1 shows the system configuration of a proximity warning system according to one embodiment of the present invention, and Fig. 2 shows the configurations of a distance detection control device and an RFID tag with magnetic field detection function in this proximity warning system. In the following description, the "distance detection control device" will be simply referred to as the "detector," and the "RFID tag with magnetic field detection function" will be simply referred to as the "tag."

[0011] As conceptually shown in Fig. 1, in this approach warning system, detectors 2a and 2b and tags 3a and 3b are installed on vehicles 1a and 1b (both of which are forklifts in this embodiment), respectively. Fig. 1 shows vehicle 1a stopped with its engine off, and vehicle 1b approaching vehicle 1a.

[0012] The detectors 2a and 2b have the same configuration. As shown in the upper part of FIG. 2, they include a magnetic field transmitter that transmits an induction magnetic field containing the device ID information of the detectors 2a and 2b, a radio wave receiver, a device alarm unit that outputs a proximity alarm, and a device controller that controls these components. They also include a voltage converter that converts an external power source into a DC voltage (12V) suitable for operating the detectors 2a and 2b. In this embodiment, the external power source is linked to the on / off state of the engines of the vehicles 1a and 1b in which the detectors 2a and 2b are installed. That is, in this embodiment, the detectors 2a and 2b operate in conjunction with the on / off state of the engines of the vehicles 1a and 1b in which the detectors 2a and 2b are installed. Therefore, since the engine of the vehicle 1a in FIG. 1 is off, the detector 2a is not operating. On the other hand, since the engine of the vehicle 1b in FIG. 1 is on, the detector 2b is operating.

[0013] The tags 3a and 3b also have the same configuration, and as shown in the lower part of Figure 2, they include a magnetic field sensor unit that detects the induced magnetic field transmitted from the magnetic field transmitter unit of the detectors 2a and 2b, a radio wave transmitter unit that transmits a magnetic field detection radio wave when the magnetic field sensor unit detects the induced magnetic field, a tag alarm unit that outputs a proximity alarm, and a tag control unit that controls these, as well as a battery as a power source. That is, in this embodiment, the tags 3a and 3b operate using power from the battery. Therefore, the tags 3a and 3b in Figure 1 operate regardless of whether the engines of the vehicles 1a and 1b are on or off. Note that the tag control unit registers the device ID information of the detectors 2a and 2b installed in the vehicles 1a and 1b on which the tags 3a and 3b are installed as its own device ID information.

[0014] In FIG. 1, detector 2a installed on vehicle 1a is not operating as described above, and therefore does not transmit an induced magnetic field containing the device ID information of detector 2a from its magnetic field transmitter. Meanwhile, detector 2b installed on vehicle 1b in FIG. 1 is operating as described above, and therefore transmits an induced magnetic field containing the device ID information of detector 2b from its magnetic field transmitter. Then, when vehicle 1b approaches vehicle 1a, the magnetic field sensor unit of tag 1a installed on vehicle 1a detects the induced magnetic field transmitted from detector 2b. In a conventional system, the radio wave transmitter unit of tag 1a transmits a magnetic field detection radio wave, which is received by the radio wave receiver unit of detector 2b. As a result, a proximity alarm is output from the device alarm unit of detector 2b. As described above, this proximity alarm is an unnecessary proximity alarm.

[0015] Therefore, to prevent such unnecessary proximity alarms from being output, in one aspect of this embodiment, the tag control unit controls the radio wave transmitter to transmit a magnetic field detection radio wave only when the magnetic field sensor detects an induced magnetic field including the own device ID information and also detects an induced magnetic field including device ID information other than the own device ID information. Specifically, in the case of FIG. 1 , the magnetic field sensor unit of tag 3a does not detect an induced magnetic field including the own device ID information, which is the device ID information of detector 2a. Therefore, even if it detects an induced magnetic field including the device ID information of detector 2b, which is device ID information other than the own device ID information, the radio wave transmitter unit of tag 3a does not transmit a magnetic field detection radio wave. Therefore, a proximity alarm is not output from the device alarm unit of detector 2b. On the other hand, the magnetic field sensor unit of tag 3b detects an induced magnetic field including the own device ID information, which is the device ID information of detector 2b, but does not detect an induced magnetic field including the device ID information of detector 2a, which is device ID information other than the own device ID information. Therefore, the radio wave transmitter unit of tag 3b does not transmit a magnetic field detection radio wave. In one aspect of this embodiment, the tag control unit can be configured to transmit a magnetic field detection radio wave from the radio wave transmitting unit and output a proximity alarm from its own tag alarm unit only when the magnetic field sensor unit detects an induced magnetic field including the above-mentioned own device ID information and also detects an induced magnetic field including device ID information other than the own device ID information.

[0016] In another aspect of this embodiment, when the magnetic field sensor detects an induced magnetic field, the radio wave transmitter of each tag 3a, 3b transmits a magnetic field detection radio wave including the tag ID information of the tags 3a, 3b, the device ID information contained in the induced magnetic field, and magnetic field strength information. Then, when the magnetic field sensor detects only the induced magnetic field including its own device ID information, the tag control unit prevents the tag alarm unit from outputting a proximity alarm and adds alarm non-output information to the magnetic field detection radio wave (including the tag ID information of the tags 3a, 3b, the device ID information contained in the induced magnetic field, and magnetic field strength information) output from the radio wave transmitter to prevent the device alarm unit from outputting a proximity alarm. Specifically, in the case of FIG. 1, the detector 2a installed in vehicle 1a with its engine off does not transmit an induced magnetic field including the device ID information. Therefore, even if vehicle 1b approaches vehicle 1a, the magnetic field sensor of tag 3b installed in vehicle 1b will only detect the induced magnetic field including its own device ID information. In this case, the tag control unit of tag 3b prevents the tag alarm unit of tag 3b from outputting a proximity alarm, and adds alarm non-output information to the magnetic field detection radio waves (including the tag ID information of tag 3b, the device ID information and magnetic field strength information of detector 2b) output from the radio wave transmission unit of tag 3b to prevent the device alarm units of each detector from outputting a proximity alarm. This prevents unnecessary proximity alarms from being output from detector 2b and tag 3b installed in vehicle 1b. Meanwhile, the magnetic field sensor unit of tag 3a installed in vehicle 1a does not detect an induced magnetic field including its own device ID information, which is the device ID information of detector 2a. Therefore, even if it detects an induced magnetic field including the device ID information of detector 2b, which is device ID information other than its own device ID information, no magnetic field detection radio waves will be transmitted from the radio wave transmission unit of tag 3a, and no proximity alarm will be output from the tag alarm unit of tag 3a. In this embodiment, in either aspect, when the magnetic field sensor unit of the tag detects an induced magnetic field including its own device ID information, no approach alarm is output from its own tag alarm unit and device alarm unit.

[0017] In another aspect of this embodiment, the tag control unit controls the radio wave transmitter to transmit a magnetic field detection radio wave when the magnetic field sensor detects an induced magnetic field including the own device ID information and also detects an induced magnetic field including device ID information other than the own device ID information. Specifically, in FIG. 1, the engine of vehicle 1a is turned on and detector 2a is operating. When vehicles 1a and 1b approach each other, the magnetic field sensor of tag 3a installed on vehicle 1a detects an induced magnetic field including the own device ID information, which is the device ID information of detector 2a, and also detects an induced magnetic field including the device ID information of detector 2b, which is device ID information other than the own device ID information. Therefore, the tag control unit of tag 3a controls the radio wave transmitter of tag 3a to transmit a magnetic field detection radio wave. The magnetic field detection radio wave transmitted from the radio wave transmitter of tag 3a is received by the radio wave receiver of detector 2b installed on vehicle 1b, and a proximity alarm is output from the device alarm unit of detector 2b (this proximity alarm is not an unnecessary proximity alarm). Furthermore, the magnetic field sensor unit of tag 3b installed in vehicle 1b detects an induced magnetic field including its own device ID information, which is the device ID information of detector 2b, and also detects an induced magnetic field including the device ID information of detector 2a, which is device ID information other than its own device ID information. Therefore, the tag control unit of tag 3b causes the radio wave transmitting unit of tag 3b to transmit a magnetic field detection radio wave. The magnetic field detection radio wave transmitted from the radio wave transmitting unit of tag 3b is then received by the radio wave receiving unit of detector 2a installed in vehicle 1a, and a proximity alarm is output from the device alarm unit of detector 2a (this proximity alarm is also not an unnecessary proximity alarm). In another aspect of this embodiment, when the magnetic field sensor unit detects an induced magnetic field including its own device ID information and also detects an induced magnetic field including device ID information other than its own device ID information, the tag control unit can be configured to transmit a magnetic field detection radio wave from the radio wave transmitting unit and output a proximity alarm from its own tag alarm unit.

[0018] As described above, in another aspect of this embodiment, it is possible to prevent unnecessary proximity alarms from being output. Furthermore, according to another aspect of this embodiment, even when the magnetic field sensor unit detects only the induced magnetic field including its own device ID information, the tag control unit causes the radio wave transmitter unit to transmit a magnetic field detection radio wave including the tag ID information, the device ID information included in the induced magnetic field, and magnetic field strength information, so it is possible to detect whether the tag is operating normally.

[0019] In this embodiment, the tags 3a and 3b are equipped with a tag alarm unit, but the tag alarm unit can be omitted. Also, although two vehicles are shown in Figure 1, the number of vehicles may be three or more, and it will be obvious to those skilled in the art that the present invention is also applicable in this case. [Explanation of symbols]

[0020] Vehicles 1a and 1b 2a, 2b Detector (distance detection control device) 3a, 3b tags (RFID tags with magnetic field detection function)

Claims

1. An approach warning system that detects the approach of vehicles and outputs an approach warning, A distance detection control device and an RFID tag with a magnetic field detection function are installed in each vehicle, The distance detection control device includes a magnetic field transmission unit that transmits an induction magnetic field including device ID information of the distance detection control device, a radio wave reception unit, a device alarm unit that outputs the proximity alarm, and a device control unit that controls these units; The RFID tag with magnetic field detection function includes a magnetic field sensor unit that detects the induced magnetic field transmitted from the magnetic field transmitter unit, a radio wave transmitter unit that transmits a magnetic field detection radio wave when the magnetic field sensor unit detects the induced magnetic field, and a tag controller that controls these units; The tag control unit has registered therein, as its own device ID information, device ID information of the distance detection control device that is also installed in the vehicle in which the RFID tag with magnetic field detection function is installed, An approach warning system in which the tag control unit causes the radio wave transmitter unit to transmit the magnetic field detection radio wave only when the magnetic field sensor unit detects an induced magnetic field including the device's own ID information and also detects an induced magnetic field including device ID information other than the device's own ID information.

2. An approach warning system that detects the approach of vehicles and outputs an approach warning, A distance detection control device and an RFID tag with a magnetic field detection function are installed in each vehicle, The distance detection control device includes a magnetic field transmission unit that transmits an induction magnetic field including device ID information of the distance detection control device, a radio wave reception unit, a device alarm unit that outputs the proximity alarm, and a device control unit that controls these units; The RFID tag with magnetic field detection function includes a magnetic field sensor unit that detects the induced magnetic field transmitted from the magnetic field transmitter unit, a radio wave transmitter unit that transmits a magnetic field detection radio wave including tag ID information of the RFID tag with magnetic field detection function, the device ID information, and magnetic field strength information when the magnetic field sensor unit detects the induced magnetic field, and a tag control unit that controls these units; The tag control unit has registered therein, as its own device ID information, device ID information of the distance detection control device that is also installed in the vehicle in which the RFID tag with magnetic field detection function is installed, the tag control unit, when the magnetic field sensor unit detects only the induction magnetic field including the own device ID information, adds alarm non-output information to the magnetic field detection radio wave output from the radio wave transmitter unit to prevent the device alarm unit from outputting the proximity alarm; Furthermore, the tag control unit, when the magnetic field sensor unit detects an induced magnetic field including the self-device ID information and also detects an induced magnetic field including device ID information other than the self-device ID information, causes the radio wave transmitter unit to transmit the magnetic field detection radio wave, an approach warning system.

3. 3. The proximity warning system according to claim 1, wherein the distance detection control device operates in conjunction with turning on / off of the engine of the vehicle in which the distance detection control device is installed, and the RFID tag with magnetic field detection function is equipped with a battery and operates using power from the battery.

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