PURPOSE: To avoid radio interference among transceivers and to prevent an accident due to collision at a site where a plurality of working machines and workers are mixedly exist, by transmitting a microwave frequency-modulated by the variable pattern of the graph of a broken line to a transponder.
CONSTITUTION: A function-generating ROM 31 memorizes various variable patterns in addition to the variable pattern of the graph of a broken line for connecting to a control voltage-generating circuit 11. An MPU 32 selects and reads the variable pattern from the ROM 31 FOR D/A conversion 11a. The variable pattern is then applied to a VCO 12 to change the frequency of a transmitting signal along a straight line. After a predetermined period of time, a transmitting wave sweeped to successively change the decline of the straight line is generated to be transmitted to a trasponder 20 (worker). Thus, mutual radio interference is avoided from the difference in the timing of transmission starting even if a plurality of transceivers (working machines) selects the same transmitting pattern. Each transceiver exactly detects the distance to the transponder 20 to prevent collision.
| WO/2024/010301 | METHOD AND DEVICE FOR RECOGNIZING BOUNDARY AT CONSTRUCTION SITE |
| WO/2005/111322 | ROTATION CONTROL DEVICE, ROTATION CONTROL METHOD, AND CONSTRUCTION MACHINE |
| WO/2022/201740 | ELECTRIC WORK MACHINE |
TANAKA YASUO
YAMASHITA SEIJI
AOKI SHIGENORI
