Research On Feature-based Automatic Correction Of Mechanical Drawing Homework

Net-based distance education is one of the fastest developing fields at present, which integrates CAI, modern multimedia technology and Internet technology, makes educational resource shared by all the people, and brings vitality to traditional education with the advantages of network and multimedia technology.By analyzing several typical interactive techniques and the characteristics of long-distance teaching of mechanical drawing, the paper develops an on-line drawing system with ActiveX, which realizes that students make drawings interactively on client PC, and sends the feedbacks of learning to the teaching management system through the interface of ActiveX. It provides a platform for mechanical drawing teaching.In allusion to the characteristics of mechanical drawing and the requirements of engineering drawing, the paper improves and extends the on-line drawing tool: consummating the functions of drawing and editing, adding the function of navigation for three principal views, designing a feature-based data structure. At the same time, through the pretreatment of the students' homework, the mistakes induced by using different ways of drawing when the integrity of geometric drawing is distinguished, are removed. This further improves the automatic correcting of mechanical drawing homework.After analyzing the characteristics of dimensioning and the data structure of Binary Tree, a method is put forward to judge the integrality of dimensioning by using the closing of dimensions. By traversal of the datum of drawings, the binary trees of dimensions are built in three directions. Then using the feature-based knot datum of drawing, the automatic correction of dimensioning can be realized.In the end, give a summarization, and point out the direction, main work and proper method for further research on this task.