Multipose measurement of surface defects on rotary metal parts with a combined laser-and-camera sensor
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In manufacturing, automotive, and aerospace industries, there is a need for accurately measuring the geometric parameters of surface defects to give an approximate prediction of the remaining life of the part. For this purpose, we describe a multipose measurement system with a combined laser-and-camera sensor to measure surface defects on rotary metal parts accurately. By using the combined sensor and multipose measuring method, the system can accurately measure the defects of the whole surface with time-saving and the dimensions of the defects can be obtained. We mainly focus on system calibration and defect extraction. First, to eliminate strong correlations among all the parameters, kinematic calibration and camera position calibration are accomplished by using a designed compound calibration artifact. Second, a new defect extraction method based on contourlet transform integrating with active contour model is proposed for precisely and rapidly locating defects. Experimental tests were conducted to verify the capability of the developed system in achieving accurate measurement of surface defects on rotary metal parts. The system can measure defects down to ∼6 μm in height/depth and ∼50 μm in lateral dimension.Keywords:
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Structured Light
Stamping
Accuracy and precision
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Repeatability
Accuracy and precision
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Structured-light 3D scanner
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Structured Light
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Brittleness
Hydrostatic test
Hydrostatic equilibrium
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