The Research And Practice On Intelligent Correcting Technology Of Engineering Drawing Assignment Based On Three-dimensional Reconstruction

With the continuous deepening of the education reform, traditional engineering drawings teaching has been unable to meet the requirements of modern teaching; the rapid development and popularization of computer technology has provided the essential conditions for it. In order to improve the quality of teaching and train the standard and efficient drawing skills of students, the computer graphics has become an important part of the engineer drawing course teaching. The learning of the computer graphics software makes them to complete the engineering drawing assignment on the computer, and it is necessary to study the automatic correcting technology.At present, the main method of automatic correction of engineering drawing assignment is the direct comparison, that is, the teacher pre made the standard answer, and then compare the student's answer to it. In view of the problem that need to make the standard answer artificially, this paper puts forward the automatic correction technique of engineering drawing assignment based on the three-dimensional reconstruction. The correction method does not require teachers to make standard answer artificially, which through to make specified 2D view into three-dimensional graph and extract the key data information of the stereogram, and then compare the information of the standard drawing and student work map, to realize the intelligent correction of engineering drawing assignment.Take engineering drawings made by AutoCAD software as the research object, the paper study the intelligent correcting technology of engineering drawings based on the three-dimensional reconstruction and its realization process. At first, this paper research on the three-dimensional reconstruction technology of engineering three views, which is the basis of the intelligent correction. The paper proposes an algorithm of combination three-dimensional reconstruction based on the reconstruction method of guide model. In view of the algorithm, the paper uses VB.NET to develop the application procedure which can realize the three-dimensional reconstruction and loads on the AutoCAD. Through analyzing the format of DWG and SAT file, then the paper gives a new method which converts the DWG file to SAT file and programs using string search method to extract the three-dimensional graphics key data information. Then inputs the graphic data information into the Access database, and gives the process and rules of the intelligent correction, to provide a basis for it. Finally, according to the intelligent correction process, the paper develops the intelligent correcting system of engineering graphics based on stereo reconstruction preliminary and designs the main modules of the systems. Present the specifics implementation process of the intelligent correction technology of engineering graphics based on stereo reconstruction and achieve the established functions.