  This manuscript presents enhancements on our motion-primitives exploration
path planning method for agile exploration using aerial robots. The method now
further integrates a global planning layer to facilitate reliable large-scale
exploration. The implemented bifurcation between local and global planning
allows for efficient exploration combined with the ability to plan within very
large environments, while also ensuring safe and timely return-to-home. A new
set of simulation studies and experimental results are presented to demonstrate
the new improvements and enhancements. The method is available open source as a
Robot Operating System (ROS) package.
