110 Digest | Nauticus Robotics Aquanaut Mk2 Navigation and comms The navigation sensor package consists of an iXblue Phins 6000 fibre-optic gyro-based inertial navigation system, a Nortek DVL500 Doppler velocity log, an AML Oceanographic AML6 sound velocity, a conductivity and temperature sonde, and an Imaginex 837 AXi multibeam obstacle avoidance sonar. Positioning sensors include a Sonardyne Avtrak-6 tracking, comms and relocation transceiver, along with an increased instruction set GNSS and radio module. The underwater comms system includes both acoustic and optical bearers. The acoustic element relies principally on two devices: an M25M series modem and Dolphin Comms’ ‘direct blast’ cancellation system that enables full duplex continuous telemetry without interference from signals from the transmitter to the local receiver. Optical comms are provided by a Hydromea Luma X 10 Mbit/s optical modem with a 50 m range. In the Aquanaut’s normal operation, the assumption is that acoustic comms constraints apply, says Akinyode, but if optical communication is available, the comms system can take advantage of the greater bandwidth it provides to offload data gathered during recently executed tasks, for example. Vice-president of operations Todd Newell says the Aquanaut is one of the first autonomous vehicles to offer both survey/inspection and intervention capabilities. For survey and inspection work using data collection and perception sensors, the vehicle is said to be in ‘excursion’ mode, while with a pair of robot arms fitted for physical manipulation of underwater hardware it is in ‘intervention’ mode. Intelligent arms The manipulator arms are members of Nauticus Robotics’ Olympic Arm family, all of which are electrically powered and can be fitted with interchangeable tools. The company says full electric operation makes the arm much more environmentally friendly than hydraulic alternatives, because there is no hydraulic oil to leak, while providing sufficient lifting power to handle tasks normally undertaken by divers. The Aquanaut carries extra tools in its front trunk (‘frunk’), and can change them itself underwater, Newell says. The variant of the Olympic arm fitted to the Aquanaut can lift 60 kg at full extension and offers six degrees of freedom in motion, plus the gripper’s n x 360o of rotation and opening and closing movements. The gripper can exert a force of 454 kg, and includes a set of force-feedback sensors to allow some delicacy of operation to complement its power. The arm itself weighs 109 kg in air or 73 kg in water, and measures 584.2 mm long, 266.7 mm wide and 977.9 mm high when stowed. The Aquanaut’s sensors and manipulators are coordinated locally by onboard algorithms, Akinyode adds. Basic tasks such as station-keeping and manipulation tasks are controlled autonomously by the vehicle, while the operator has responsibility for high-level task direction of the platform. Both the Aquanaut and the Olympic arms also feature the company’s Azimov system, which is designed to ensure safe operation near people, equipment and infrastructure. Fine control of the manipulators is also the responsibility of the October/November 2023 | Uncrewed Systems Technology The Aquanaut is fitted with lifting eyes to ease ground handling and to allow it to operate from vessels of opportunity equipped with conventional launch & recovery equipment. Note the comms/navigation mast The Aquanaut is one of the first vehicles of its kind to offer both survey/inspection and intervention. It carries extra tools it can change itself
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