dc.description.abstract | Traditional extrusion based Additive Manufacturing (AM) is realized using a 3 Degrees
of Freedom (DOF), translation only, 3D printer. Here, the printer must be larger than
the printed part. One way of enabling AM in large-scale is to combine AM with
robotics. By using a 6 DOF robot manipulator to extrude a fast-curing material, the
workspace of the build would be greatly expanded and it would be possible to increase
the flexibility of the building process itself since the structure would no longer have
to be built from the bottom-up approach which is necessary for most existing forms
of AM. This could possibly reduce the need for support structures to the point of
only relying of anchoring and stabilizing. In this thesis, a method for generating a
path for AM using robot manipulators that takes advantages of the robots DOF is
presented. The path is generated based on simple surfaces in CAD models. First, the
surface(s) is sampled and the samples are gathered in a point cloud. Then, a path is
generated based on the point cloud using a path generation algorithm. Three different
path generation algorithms was implemented and tested: greedy choice, weighted
greedy choice and Travelling Salesman Problem (TSP). Out of the three algorithms,
the weighted greedy choice algorithm shows the most promise. With this algorithm,
paths that enable printing along curved surfaces and reducing the need for support
structures was generated. The method is effective, and by interfacing with FreeCAD, it
is easy to review the generated paths through visual aids. It is, however, important to
mention that the method only generates paths based on simple surfaces and is based
on the assumption of fast-curing material enabling mid-air printing. | |