PURPOSE: To exactly detect the turning position with respect to the ground of a turning base by using a system in which lasers from a laser projector on the land is received in a selective manner by a large number of laser receiving sensors attached to the periphery of the shaft of the turning base.
CONSTITUTION: A laser projector L is set on a specific position on the land, and a large number of laser receiving sensors S are attached in order on all the periphery of the rotary shaft of a turning base 1. The laser from the laser projector L is received by the sensor S in a selective manner as the turning base 1 turns, thereby permitting the turning position against ground of the turning base 1 to be detected based on which of the sensors S is in laser-receiving state.
TABUCHI YOSHINOBU
TSUTSUMI MASAHIRO
TSUDA AKIRA
MOURI AKIHIKO
