Appearance measuring and detecting method for inner surface of space curve type long-distance microtubule

Abstract

The invention discloses a method for checking the surface condition of spatial curvature long-distance micro tube. The inventive machine is mainly formed by a two-dimension position sensor, a semi-conductor laser, a transparent window, a micro motor, a scanning mirror, a reflector, a convergent lens, and a receiving lens. The light of laser via two reflections will form a micro spot on the inner wall of tube, while said spot is received by the two-dimension position sensor. Via the current signal of two-dimension position sensor and the structural parameters of inventive machine, the invention calculates out the position of the spot in local three-dimension coordinate. The micro motor rotates the scanning mirror one round to obtain the positions of all sampling points of one section of inner wall of tube. The invention can be used in the defect check and three-dimension measurement of the inner wall of the curvature micro tube whose inner diameter is 9-11mm and radius is larger than 100mm, while the measurement accuracy can reach +- 0.1mm.

Description

technical field [0001] The invention relates to a method for measuring and detecting the inner surface topography of a space curve type long-distance micro-pipe. Background technique [0002] A large number of pipeline parts are used in many industries such as machinery, energy, chemical industry, etc. After long-term use, defects such as cracks may appear, which may cause gas or liquid leakage, damage the entire system, and cause unnecessary economic losses, and even endanger the lives of staff. Therefore, the detection of such parts has become a very important subject. Many literatures at home and abroad have done in-depth research on this issue, but most of them are for pipes with an inner diameter greater than 20mm, and there are few research reports for small pipes, especially those with an inner diameter of less than 10mm. [0003] The detection technology of the inner wall of large pipes is relatively mature. The most common method is to use a CCD camera to image th...

AI Technical Summary

Problems solved by technology

Because the processing circuit of the CCD chip is complex and miniaturization is difficult, it is difficult for ordinary CCD cameras to enter the interior of small pipes.

Although the special industrial electronic endoscope can detect the inner wall of small pipes, it is difficult to determine the size of the defect, the specific spatial location and the three-dimensional shape of the inside of the pipe.

Although the micro pipeline robot developed by Tsuruta k. et al. can also enter the 10mm pipeline for detection, it can only observe the inner wall of the pipeline by the pictures taken by the CCD, and cannot make up for the above-mentioned shortcomings of the endoscope.

Mizunuma M and others used the position sensor PSD (Position Sensitive Detector) to realize the detection and three-dimensional reconstruction of the inner wall of the pipeline, but the rotation mechanism of the system developed by them is complicated, and it is only suitable for straight pipes with an inner diameter of 66-83mm, and cannot detect curved pipes or tiny pipe

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