A motion planning strategy was developed and implemented to generate motion control instructions from solid model data for controlling a robotically driven solid free-form fabrication process. The planning strategy was tested using a PUMA type robot arm integrated into a LENS/sup TM/ (Laser Engineered Net Shape) system. Previous systems relied on a series of x, y, and z stages, to provide a minimal coordinated motion control capability. This limited the complexity of geometries that could be constructed. With the coordinated motion provided by a robotic arm, the system can produce three dimensional parts by "writing" material onto any face of existing material. The motion planning strategy relied on solid model geometry evaluation and exploited robotic positioning flexibility to allow the construction of geometrically complex parts. The integration of the robotic manipulator into the LENS/sup TM/ system was tested by producing metal parts directly from CAD models.

We describe the implementation and performance of Archimedes 2, an integrated mechanical assembly planning system. Archimedes 2 includes two planners, two assembly sequence animation facilities, and an associated robotic workcell. Both planners use fully 3 dimensional data. A rudimentary translator from high level assembly plans to control code for the robotic workcell has also been implemented. We can translate data from a commercial CAD system into input data for the system, which has allowed us to plan assembly sequences for many industrial assemblies. Archimedes 2 has been used to plan sequences for assemblies consisting of 5 to 109 parts. We have also successfully taken a CAD model of an assembly, produced an optimized assembly sequence for it, and translated the plan into robot code, which successfully assembles the device specified in the model.