APPROACH WARNING SYSTEM

To prevent approach warning from being output to an operator (heavy machine operator) on a driver seat of a heavy machine without adding a new device concerning an approach warning system in the periphery of the heavy machine.SOLUTION: An approach warning system outputs approach warning by detecting an approach of a detector 2 installed in a driver seat of a heavy machine 1 or in the neighborhood thereof to tags 4a and 4b attached to operators 3a and 3b. The detector 2 includes a magnetic field transmission section, an electric wave reception section, a device warning section, and a device control section. Each one of the tags 4a and 4b includes: a magnetic field sensor section for detecting an induction magnetic field to be transmitted from the magnetic field transmission section; an electric wave transmission section for transmitting a magnetic field detection electric wave when the magnetic field sensor section detects the induction magnetic field; a tag warning section; and a tag control section. When intensity of the induction magnetic field detected by the magnetic field sensor section is equal to or more than a predetermined threshold, the tag control section prevents the tag warning section from outputting approach warning and also prevents the electric wave transmission section from transmitting the magnetic field detection electric wave.SELECTED DRAWING: Figure 1 【課題】重機周りの接近警報システムにおいて、新たな装置を追加することなく、当該重機の運転席にいる作業者（重機運転者）に対して接近警報が出力されないようにする。【解決手段】重機１の運転席又はその近傍に設置された検知機２と、作業者３ａ，３ｂに取り付けられたタグ４ａ，４ｂとの接近を検知して接近警報を出力する接近警報システムにおいて、検知機２は、磁界送信部と、電波受信部と、装置警報部と、装置制御部とを備え、タグ４ａ，４ｂは、前記磁界送信部から送信される誘導磁界を検知する磁界センサ部と、当該磁界センサ部が前記誘導磁界を検知したときに磁界検知電波を送信する電波送信部と、タグ警報部と、タグ制御部とを備え、タグ制御部は、磁界センサ部が検知した誘導磁界の強さが所定の閾値以上の場合、タグ警報部から接近警報を出力させないと共に、電波送信部から磁界検知電波を送信させない。【選択図】図１