DIRECTION DETECTION SYSTEM, CONSTRUCTION MACHINE INCLUDING THE SAME, AND DIRECTION DETECTION PROGRAM

To provide a direction detection system capable of accurately detecting the direction of an upper revolving body with respect to a lower traveling body of a construction machine, a construction machine equipped with the direction detection system, a direction detection program, and an antenna device.SOLUTION: A direction detection system 1 includes a plurality of RFID (radio frequency identification) tags T1 to T8 interlocking with one of an upper revolving body 12 and a lower traveling body 11 included in a construction machine, an RFID antenna A1 interlocking with the other of the upper revolving body 12 and the lower traveling body 11 and receiving identification information of any RFID tag corresponding to the direction of the upper revolving body 12 among the plurality of RFID tags T1 to T8 by radio, and a detection unit 13 for detecting the direction of the upper revolving body 12 with respect to the lower traveling body 11 based on the identification information received by the RFID antenna A1.SELECTED DRAWING: Figure 1 【課題】建設機械の下部走行体に対する上部旋回体の向きを精度良く検出することが可能な方向検出システム、それを備えた建設機械、方向検出プログラム、及び、アンテナ装置を提供すること。【解決手段】方向検出システム１は、建設機械を構成する上部旋回体１２及び下部走行体１１の一方に連動する複数のＲＦＩＤ（Ｒａｄｉｏ Ｆｒｅｑｕｅｎｃｙ ＩＤｅｎｔｉｆｉｃａｔｉｏｎ）タグＴ１〜Ｔ８と、上部旋回体１２及び下部走行体１１の他方に連動し、複数のＲＦＩＤタグＴ１〜Ｔ８のうち上部旋回体１２の向きに対応する何れかのＲＦＩＤタグの識別情報を無線受信するＲＦＩＤアンテナＡ１と、ＲＦＩＤアンテナＡ１によって受信された識別情報に基づいて下部走行体１１に対する上部旋回体１２の向きを検出する検出部１３と、を備える。【選択図】図１