  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. 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. Experiments are conducted to demonstrate the performance of our
method.
