摘要 |
PROBLEM TO BE SOLVED: To improve measurement precision of a displacement detector by accurately detecting a flexure of a frame to which the displacement detector is fitted.SOLUTION: Vertical flexure of a frame body 23L to which two-dimensional laser displacement detectors 21, 23, and 25 are fitted is calculated using targets 43, 44 provided on an upper or lower surface of an end part of the frame body and laser displacement gauges 41, 42 which measure distances to inclined surfaces of the targets. The targets are fitted to the upper surface or lower surface of the frame body and then the inclined surfaces of the targets have a predetermined angle to the upper surface or lower surface of the frame body. If the frame body flexes in the vertical direction, the targets also move in the vertical direction. The distances from the laser displacement gauges to the inclined surfaces of the targets vary as the targets move, so a flexure amount in the vertical direction is calculated based upon the distances and the angle of the inclined surfaces which have changed. An influence of the calculated flexure is removed from displacement or the like of a rail so as to improve measurement precision of two-dimensional laser displacement detectors. |