Understanding assembly illustrations in an assembly manual without any model of mechanical parts

A discussion is presented of how to understand assembly illustrations in an assembly manual without basing it on any model of mechanical parts. The discussion is based on the following two basic prerequisites. The first is that at the present stage mechanical parts are assumed to be in the shape of or composed of cylinders. The second is to recognize the 3-D-structure of mechanical parts by using the assembly information obtained from auxiliary lines. A hierarchical approach is developed to understand an assembly illustration. Also presented is a `generated´ structure understanding scheme. The scheme finds the generated structure in the succeeding illustration, by using preliminary information on the generated structure from the current assembly illustration. The preliminary information is obtained by understanding the current assembly illustration