The Distance Changing Filing Algorithm Based On Center Retracting

This paper is mainly about the researches of path planning and scanning strategy in FDM system. In the article, a new filling algorithm is demonstrated, and the corresponding principle and efficiency of this algorithm are detailedly discussed. Also, the simulating programme is developed to demo this algorithm in the Visual C++ platform.Filling (scanning) is a key step in rapid prototyping process, and the quality of the products mainly depends on this. In FDM system, the product is molded by silk which is from sprayer, and the basic operation is to scan slice. In the depositing process, the sprayer will do much movement, so the proper scanning path plays a important role in the quality of the products.The distance changing filing method based on the center retracting is an offsetting algorithm. Compared to the traditional scanning method, it has the advantage of lower times of silk breaking down, better performance in energetics. Because the distance in scanning operation is changing, it can avoid the defect called ring-meets.To enlarge the using range of this filling algorithm, the paper also develops a fast algorithm to decompose the concave polygon to protruding polygon. This algorithm can find out concave points quickly and decomposed them to protruding point. Also, It has high efficiency by contrasting to the conventional algorithm.Besides, aimed at solving the problem which contour has inner rings, the paper develops an algorithm to redefine the processing area. The algorithm divides processing area into some sub areas, and then used distance changing filling method in sub areas respectively. This algorithm extends the range that the distance changing filing algorithm based on center retracting can be used successfully.