  This paper presents an integrated system for performing precision harvesting
missions using a legged harvester. Our harvester performs a challenging task of
autonomous navigation and tree grabbing in a confined, GPS denied forest
environment. Strategies for mapping, localization, planning, and control are
proposed and integrated into a fully autonomous system. The mission starts with
a human mapping the area of interest using a custom-made sensor module.
Subsequently, a human expert selects the trees for harvesting. The sensor
module is then mounted on the machine and used for localization within the
given map. A planning algorithm searches for both an approach pose and a path
in a single path planning problem. We design a path following controller
leveraging the legged harvester's capabilities for negotiating rough terrain.
Upon reaching the approach pose, the machine grabs a tree with a
general-purpose gripper. This process repeats for all the trees selected by the
operator. Our system has been tested on a testing field with tree trunks and in
a natural forest. To the best of our knowledge, this is the first time this
level of autonomy has been shown on a full-size hydraulic machine operating in
a realistic environment.
