ROS 2-Based Flexible Behavior Engine for Flexible Navigation

Hierarchical Finite State Machines (HFSM) are commonly used as high-level behavioral control strategies for robotic systems. Over the years a number of behavior engines have been developed for the original Robot Operating System (ROS 1), including the popular Flexible Behavior Engine (FlexBE). In recent years a new ROS 2 system has been developed to improve communication performance by using the Data Distribution Service (DDS) protocol. This paper describes the conversion of both FlexBE and the open-source Flexible Navigation system to the latest ROS 2 release, and our experiments with the new system. Both ROS 2 conversions are released as open-source and available for use by the robotics community.