Cultural relic object high-precision micro-deformation monitoring method based on uncontrolled scanning point cloud

Abstract

The invention discloses a cultural relic object high-precision micro-deformation monitoring method based on uncontrolled scanning point cloud. The method comprises the following steps: step 1, continuously carrying out data acquisition twice on a cultural relic object in a period to obtain two data: carrying out registration by applying an ICP algorithm to obtain registration precision sigma 0 ofan articulated arm scanning point cloud under the condition that the surface of the cultural relic object is not changed; then solving a median error sigma d of the deformation measurement D; step 2,carrying out data acquisition on the cultural relic object in another period, and carrying out grid iteration method registration on the first data of the two periods to enable the registration precision to be less than or equal to sigma 0; and step 3, calculating a deformation measurement D by using the first data of the two stages, and taking a value of the D value change exceeding a confidenceinterval (-m sigma d to + m sigma d) as a change value of the cultural relic object. According to the method, on the premise that the targets are not arranged and the body is not damaged, the minimumvariable quantity and the variable quantity distribution which can be monitored are evaluated, and scientific data reference is provided for cultural relic protection.

Description

technical field [0001] The invention belongs to the field of construction, and relates to a high-precision micro-deformation monitoring method of a cultural relic object based on an uncontrolled scanning point cloud. Background technique [0002] The weathering and shedding of the surface of cultural relics is the main factor causing the demise of the statues. Since the surface changes of cultural relics are often small changes in a continuous sheet, the traditional deformation monitoring method based on monitoring points cannot capture the overall deformation of the surface. Three-dimensional laser scanning technology is used for deformation Monitoring is undoubtedly the ideal method. However, laser scanning point cloud monitoring based on target points is not suitable for micro-deformation monitoring of cultural relic objects, because its surface or its environment does not allow the deployment of target points; so it is necessary to study cultural relics based on uncontro...

AI Technical Summary

Problems solved by technology

The point cloud resolution, accuracy, and integrity of ordinary terrestrial lidars cannot meet the requirements for monitoring the above-mentioned small random deformations. In contrast, high-resolution and high-precision articulated arm scanners can meet the requirements of such objects. However, since the surface of the cultural relic object and its environment cannot place a target, the study of the high-precision registration method of the point cloud of the target-free joint arm is a key issue for such small deformations

At present, the target-free laser scanning point cloud registration is mainly to extract the feature points, lines, and surfaces of the object point cloud, but this method is not suitable for scanning point clouds that are not deformed at the same time

It seems that the registration of deformed data without a target is an unsolvable problem

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