  Multi-axis additive manufacturing enables high flexibility of material
deposition along dynamically varied directions. The Cartesian motion platforms
of these machines include three parallel axes and two rotational axes.
Singularity on rotational axes is a critical issue to be tackled in motion
planning for ensuring high quality of manufacturing results. The highly
nonlinear mapping in the singular region can convert a smooth toolpath with
uniformly sampled waypoints defined in the model coordinate system into a
highly discontinuous motion in the machine coordinate system, which leads to
over-extrusion / under-extrusion of materials in filament-based additive
manufacturing. The problem is challenging as both the maximal and the minimal
speeds at the tip of a printer head must be controlled in motion. Moreover,
collision may occur when sampling-based collision avoidance is employed. In
this paper, we present a motion planning method to support the manufacturing
realization of designed toolpaths for multi-axis additive manufacturing.
Problems of singularity and collision are considered in an integrated manner to
improve the motion therefore the quality of fabrication.
