Patent ID: 9062963
Filing Date: 2015-06-23
Classification: G01B

Abstract:
1. A thickness measurement system configured to continuously measure a thickness of a conveyed plate as a measurement target, the system comprising: a first thickness measurement apparatus and a second thickness measurement apparatus each measuring the thickness of the measurement target using a laser, the first thickness measurement apparatus being disposed on an upstream side and the second thickness measurement apparatus being disposed on a downstream side in such a manner that a measurement position for the first thickness measurement apparatus and a measurement position for the second thickness measurement apparatus are separated from each other by a predetermined distance in a traveling direction of the measurement target; an operation mode setting section configured to periodically set a “calibration” mode or a “measurement” mode in a switchable manner as an operation mode for the first thickness measurement apparatus, while synchronously setting a “measurement” mode or a “measurement value correction” mode in a switchable manner as an operation mode for the second thickness measurement apparatus; position setting means configured to set, in accordance with the operation mode, a position of the first thickness measurement apparatus at a measurement position where the measurement target is measured or a calibration position where a reference object disposed at a position different from a position of the measurement target is measured, with a measurement result calibrated; a speed detector configured to detect a traveling speed of the measurement target; and thickness calculation means configured to calculate and output the thickness of the measurement target at regular intervals based on measurement results from the first thickness measurement apparatus and the second thickness measurement apparatus and a detection result from the speed detector, wherein the thickness calculation means selectively outputs the measurement result from the second thickness measurement apparatus set in the “measurement” mode when the first thickness measurement apparatus is in the “calibration” mode, and when the first thickness measurement apparatus is in the “measurement” mode, delays the measurement result obtained from the upstream-side first thickness measurement apparatus after calibration for the first thickness measurement apparatus is completed, based on a detection speed obtained by the speed detector and a separation distance between the first thickness measurement apparatus and the second thickness measurement apparatus, to allow the measurement position for the first thickness measurement apparatus to coincide with the measurement position for the second thickness measurement apparatus, determines a difference between the measurement results as a correction value, and corrects the thickness measurement result from the second thickness measurement apparatus set in the “measurement value correction” mode.