Autonomous Rule-Based Robot Navigation in Orchards

Orchard navigation using sensor-based localization and flexible mission management facilitates successful missions independent of the Global Positioning System (GPS). This is especially important while driving between tight tree rows where the GPS coverage is poor.This paper suggests localization based on an a priori map of the tree rows, a laser scanner based tree row detection, detecting both the row line and the row ends. The localization is combined with mission objectives in a rule-based inference interpreter. This rule-based mission handler combines the functional modules: localization, obstacle avoidance, path planning and drive control.The system is tested successfully using a Hako 20 kW tractor during autonomous missions in both cherry and apple orchards with mission length of up to 2.3 km including the headland turns.