A 3D Shape Measurement Technique that Makes Use of a Printed Line Pattern

Abstract

The in-house validation of finite element models for bird strike events is currently done by experimental tests on flat plates. High displacement speeds in these experiments demand a small exposure time of the high speed camera (up to 1/50000 s). In order to acquire images of sufficient quality, a special, highintensity light source has to be used, which is not always possible. The regions with high displacement speeds, therefore, often result in blurry images. In this case, a printed line pattern to estimate the shape of the plate during test provides major advantages over a speckle pattern in terms of reconstruction and optimization of the blurry regions. In this work, a stereo vision technique is developed to reconstructs 3D shape maps using images of impacted plates with printed line patterns. It is shown that two cameras are necessary to calculate accurate shape maps in case of large deflections. The resulting shapes can be used for the validation of numerical simulations.

Centrosymmetric 3D Deformation Measurement using Grid Method with a Single-Camera

“…Since Barnard proposed computer vision technology [14] in 1982, many measurement methods for 3D deformation have been developed and applied in measuring different types of highspeed deformation and dynamic mechanical performance. These applications include random nonlinear dynamic response [15], simulation of artificial wing modal analysis of an underwing beetle [16], high-speed impact [17][18][19], and Hastelloy-X high-temperature vibration response [20]. However, system errors caused by the non-synchronization of the acquisition time are inevitable because of the use of a pair of high-speed cameras.…”