Towards Dynamics Modeling for an Autonomous Underwater Vehicle (AUV) in Experimental and Simulated Settings

Abstract

Autonomous Underwater Vehicles (AUVs) have been in development in recent decades to address the difficulties and high costs of oceanic exploration, with a myriad of applications including marine life monitoring and search and rescue operations. An underwater robot in development by the Interactive Robotics and Vision (IRV) Laboratory at the University of Minnesota is LoCO, a Low Cost Open-Source AUV aiming to reduce the current high cost of entry into underwater robotics. One aspect critical to its capacity as an AUV is its autopilot system, which enables stability augmentation and predictable control behavior. Each new AUV comes with unique characteristics, requiring distinctive autopilot designs. This research seeks to prove the hypothesis that the known properties common to underwater environments (e.g., buoyancy and drag forces) can be characterized alongside parameterized variables adaptable to various AUV configurations. This understanding will lead to the efficient development of autopilot systems based on both dynamics modeling and experimental data, opposed to the purely experimental approximation of control parameters. Focusing on LoCO, this particular research centered on the development of a simulation program in Gazebo utilizing Robot Operating System (ROS) that has the potential to reduce time and cost spent on physical testing. Various physics aspects for simulated locomotion were considered alongside the implementation of initial underwater forces. Experimental data from physical testing was collected to characterize LoCO’s forward motion to aid in this initial modeling. Further evaluation and validation of dynamics modeling will build upon this framework, assisting in future control system development.