Self-adaptive speckle interference measurement method and system

Abstract

The invention relates to the technical field of optical measurement, in particular to a self-adaptive speckle interference measurement method and system, and the method comprises the steps: obtaining a group of speckle images of an object to be detected according to the exposure time from short to long in each phase shift based on a four-step phase shift algorithm, and obtaining four groups of reference speckle images; performing image fusion on each group of reference speckle images to obtain four reference speckle fusion images; obtaining four groups of deformed speckle images based on a four-step phase shift algorithm; performing image fusion on each group of deformed speckle images to obtain four deformed speckle fusion images; and storing the four deformed speckle fusion images and the four reference speckle fusion images in a GPU memory, determining the deformation phase of the to-be-detected object according to the four deformed speckle fusion images and the four reference speckle fusion images through parallel calculation, and completing real-time display. According to the invention, the stability and applicability of phase measurement are improved.

Description

Technical field [0001] The present invention relates to the field of optical measurement technology, in particular to an adaptive speckle interferometry method and system. Background [0002] Speckle interferometry is a precision measurement technique based on the principle of optical interference. Depending on the specific optical arrangement, speckle interferometry can be used to measure full-field deformation in and out of the surface. Shear imaging simplifies the optical arrangement by using a shearing device, measuring the derivative of the out-of-plane deformation by setting the shear amount and shear direction. The interferometer uses the wave characteristics of coherent light to analyze surface properties, including in-plane and out-of-plane displacements and gradients. If a controllable phase shift is introduced in the interferometer, the path difference between the two beams produces a given constant phase. By introducing phase shift technology, the contrast of the int...

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Problems solved by technology

However, in the non-destructive inspection of rubber-coated structures that do not allow surface treatment, such strong reflection spots can lead to loss of measurement information in the overexposed regions of the speckle image

[0004] To sum up, due to factors such as illumination arrangement, object surface curvature and sample reflectivity, the quality of the calculated phase image is often poor, which leads to the low applicability of the existing methods and the relatively complicated arrangement, resulting in low phase measurement accuracy.

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