MICRO-ROBOT FOR MEASUREMENT AND THREE-DIMENSION RECONSTRUCTION OF MICROPIPES

The presented system consists of field devices, a control system and a host computer system. The field devices, which are composed of an in-pipe micro-robot, a displacement sensor, a curvature sensor, and an inner surface measurement unit, can go into the pipe to get the data of displace- ment and axis curvature, and the shape data of the inner surface. With the conic-shape laser beam shot by the inner surface measurement unit, the intersectional curve between the laser beam and the inner-surface of the tested pipe can be calculated in the local coordination system （LCS） of the inner surface measurement unit. The relation between the LCS and the global coordination system （GCS） can be deduced, too. After the robot reaches the end of the pipe, all measured intersectional curves can be translated into the same coordination system to become a point cloud of the inner surface of the pipe according to the relations between LCS and GCS. Depending on this points cloud, the CAD model of the inner surface of the pipe can be reconstructed easily with reverse engineering tools, and the feature of flaw of the pipe can be obtained with flaw analysis tools.