A novel method for tracing and digitizing the 3D ice shape

Traditional method of tracing and digitizing the ice shape in the icing research tunnels(IRT) is a time consuming process and the errors lie on many factors. Based on the technology of machine vision (MV), the present study proposes a novel approach to trace the 3D ice shape on the wings in the icing experiment and the result is inherently digitized. An instrument used for tracing and digitizing the 3D ice shape was designed, assembled and calibrated by the authors. The main components of the instrument include two detectors and each detector is composed of a laser which can project line structured light and a CMOS camera. So the instrument can be seen as a line structured light binocular vision measurement system. Besides, a multifunctional shelf which can be used to mount the planar calibration target and the object to be measured was designed and manufactured. With the help of the shelf, a few images photographed in one time can be used to accomplish the calibration of the camera parameters, the plane equation of the laser light, and the relative position and orientation of the two cameras. Experiments are taken and the results show that the method is feasible and instrument can get a high accuracy digitized ice shape data swiftly and automatically.