Reinforcement learning-based framework for whale rendezvous via autonomous sensing robots

• Published in: Science robotics 2024-10, Vol.9 (95), p.eadn7299
• Main Authors: Jadhav, Ninad, Bhattacharya, Sushmita, Vogt, Daniel, Aluma, Yaniv, Tønnesen, Pernille, Prabhakara, Akarsh, Kumar, Swarun, Gero, Shane, Wood, Robert J, Gil, Stephanie
• Format: Article
• Language: English
• Subjects: Acoustics; Algorithms; Animals; Computer Simulation; Diving - physiology; Equipment Design; Radar; Reinforcement, Psychology; Robotics - instrumentation; Sperm Whale - physiology; Vocalization, Animal - physiology
• ISSN: 2470-9476; 2470-9476
• DOI: 10.1126/scirobotics.adn7299

Rendezvous with sperm whales for biological observations is made challenging by their prolonged dive patterns. Here, we propose an algorithmic framework that codevelops multiagent reinforcement learning-based routing (autonomy module) and synthetic aperture radar-based very high frequency (VHF) signal-based bearing estimation (sensing module) for maximizing rendezvous opportunities of autonomous robots with sperm whales. The sensing module is compatible with low-energy VHF tags commonly used for tracking wildlife. The autonomy module leverages in situ noisy bearing measurements of whale vocalizations, VHF tags, and whale dive behaviors to enable time-critical rendezvous of a robot team with multiple whales in simulation. We conducted experiments at sea in the native habitat of sperm whales using an "engineered whale"-a speedboat equipped with a VHF-emitting tag, emulating five distinct whale tracks, with different whale motions. The sensing module shows a median bearing error of 10.55° to the tag. Using bearing measurements to the engineered whale from an acoustic sensor and our sensing module, our autonomy module gives an aggregate rendezvous success rate of 81.31% for a 500-meter rendezvous distance using three robots in postprocessing. A second class of fielded experiments that used acoustic-only bearing measurements to three untagged sperm whales showed an aggregate rendezvous success rate of 68.68% for a 1000-meter rendezvous distance using two robots in postprocessing. We further validated these algorithms with several ablation studies using a sperm whale visual encounter dataset collected by marine biologists.