The paper reports a system which builds asseblies by simulating in virtual space assembly operations specified in an assembly manual. A manual consists of both illustration and explanation.
Illustration consists of not only figures but also phrases and symbols which relate the phrases to the figures. This research uses the three dimensional models of mechanical parts generated with a modeling tool.
A noun phrase in illustration specifies the name of a mechanical part and determines the model used. A verb phrase imposes an initial condition to be held before the execution of an assembly operation.
Auxiliary lines in an illustration are virtual lines, which are used to mate the parts at both ends of them. Both the assembly way and the terminal condition of the operation are elucidated in explanation.
The state of a subassembly obtained is hard to infer because an operation often occurs a side effect, which is affected with the geometries of the parts involved in the operation. Configuration obtained with simulation is propagated to inference mechanism and this allows the system recognize the state of the machine assembled.