PURPOSE: To provide a method and an apparatus for measuring an accurate conduit shape without necessity of installing a sensor, etc., on the ground with out influence of a circumferential magnetic element.
CONSTITUTION: A conduit shape measuring train D in which a plurality of measuring unit vehicles α1-α4 for placing laser light oscillators 7a-7e having photoreceivers 6a-6e and fluctuation and turning control means 11a-11e to be controlled by detection signals of the photoreceivers 6a-6e are coupled is traveled through a conduit, relatively varying fluctuating and turning angles Δ1-Δ5 of the means 11a-11e of the oscillators 7a-7e and developing distances L1-L3 between central vehicles between the vehicles α1-α4 are detected, and a bent state, etc., of a conduit β is sensed.
HONJO KATSUHIKO
HOSHITANI KUNIO
KUROSAWA TOMOHIRO
KAWABATA KAZUYOSHI
