PURPOSE: To prevent interference between stations and between automatically guided vehicles from being generated and to control the operation of the automatically guided vehicle normally, by providing polarizing filters at the transmission parts of projectors and light receivers provided on the ground and the vehicle of each station respectively.

CONSTITUTION: On the automatically guided vehicles 1a and 1b, the projectors 6a∼6d and the light receivers 7a∼7d are provided as interlocking sensors between the automatically guided vehicles 1a and 1b and the stations 2a and 2b, and vertical polarizing filters 10a∼10d which pass only the vertical components of a beam of light are mounted on the projectors 6a∼6d, and horizontal polarizing filters 11a∼11d which pass only the horizontal components of the beam of light on the light receivers 7a∼7d. Meanwhile, the projectors 4a and 4b, and the light receivers 5a and 5b are provided on the station 2a and 2b sides, and horizontal polarizing filters 8a and 8b which pass only the horizontal components of the beam of light, and vertical polarizing filters 9a and 9b which pass only the vertical components of the beam of light are mounted on them.