Method for measuring object deformation in real time

Abstract

The invention discloses a method for measuring object deformation in real time, which comprises the following steps: arranging and adjusting measuring equipment, namely symmetrically arranging two cameras and corresponding LED illumination lamps above a measured object, and making optical axes of the two cameras intersected in a distance of 1 meter in front of the cameras; then calibrating the cameras, namely tightly sticking mark points to the surface of an object to be measured according to the size and shape of the measured object and the measurement requirement; next, placing the measured object stuck with the mark points under the two cameras in about 1 meter or moving the whole measuring equipment to make the measured object enter a measurement range and enable each camera to acquire the mark points on the surface of the measured object, starting the two cameras to shoot sequence images, and acquiring digital images; then identifying and positioning the images; reversely solving a projection matrix according to the calibration result of the cameras, and combining image coordinates of the solved mark points on the surface of the measured object on the images of the two cameras to reconstruct a three-dimensional coordinate of the mark points; and finally, carrying out deformation analysis and calculation for the mark points on the surface of the measured object.

Description

technical field [0001] The invention relates to a three-dimensional optical measurement method, in particular to a real-time measurement method suitable for object deformation. Background technique [0002] Deformation measurement is an important part of solid mechanics and material science research. Therefore, accurate, fast and efficient measurement of material deformation is an important research content of experimental mechanics. There are mainly two types of methods to dynamically measure the motion and deformation information of objects: contact and non-contact. [0003] Contact measurement methods mainly include photoelastic patch method and resistance strain gauge measurement method. Among them, the photoelastic patch method can be used to measure the dynamic stress, static stress, elastic stress and residual stress of structures or parts made of metal, concrete, wood, rock, rubber and other materials, but this method has very high requirements for the patch. High,...

AI Technical Summary

Problems solved by technology

The holographic interferometry has high detection sensitivity and precision. The disadvantage is that it has no penetrating ability to opaque objects. Generally, it can only be used for thin materials with small thickness. The equipment is relatively expensive, and it is affected by mechanical vibration, acoustic vibration ( Such as environmental noise) and ambient light, etc. have great interference, so it needs to be tested in a quiet and clean dark room

However, when the moiré method is used to measure small strains in the elastic range, the sensitivity and accuracy are not enough, and this method is greatly affected by external vibrations.

Since the electronic speckle interferometry technology is based on two-beam interference, it has certain requirements for the detection environment and the detection object, the experiment is difficult, and the equipment is expensive, which limits the general application of this technology.

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