Uncrewed Systems Technology 046

54 “We record and store all the navigation data at a rate of 20 Hz and make it available to the customer in case they really want to go into thin levels of detail on what their YUCO has been up to underwater. And any update to the navigation software or middleware can be uploaded over wi-fi; we don’t want users to have to recover, let alone open, their YUCO to update it.” Power The thruster is an electric motor system based closely on the reference design behind Blue Robotics’ T200, Seaber having selected it for its reputation as a low maintenance system and being easily disassembled and cleaned. The system has a maximum power output of about 600 W, running on 7-20 V with 76 mm-diameter prop blades, and steering is handled by three servo motors operating the fins. “We also provide spare propellers and replacement fins for maintaining the powertrain, but to date we’ve not seen any fins broken by the work our clients do,” Simon notes. Energy of 600 Wh is stored in an IATA- certified lithium-ion battery, although an NiMH battery with 200 Wh is also available for customers to transport the YUCO by air more easily. As indicated, the pack sits on a plate that is actuated forwards or back on a rail to keep the centre of buoyancy in the middle of the vessel. “We’ve prepared the electronics to run on any bus, with various voltages and comms protocols depending on what customers want and how the electronics are optimised in the future,” Simon adds. Payloads Five versions of the YUCO were available at the time of writing. The YUCO-Physico was previously discussed in UST 42 (February/March 2022) in relation to its nose cone integrating AML Oceanographic’s AML-3 sonde for water quality measurements. Its name signifies that up to three sensors can be inserted at once, for gauging parameters such as sound velocity, conductivity and turbidity. At 123 cm long, it is the lengthiest YUCO so far. Meanwhile, the 112 cm YUCO-CTD uses RBR Global’s RBRlegato sensor for detailed conductivity, salinity and temperature measurements. The other three models are all 98 cm long. For bathymetric surveys and mapping, the YUCO-Scan integrates the 680 kHz sidescan sonar from DeepVision, the engineering of Seaber’s INX being vital for accurate geo-referencing and hence stitching of acoustic imagery taken from this payload. The YUCO-PAM (passive acoustic monitoring) uses the Porpoise recorder from RsAqua, with sampling rates of up to 384 kHz and up to 4 Tbytes of storage for detecting human-made noises such as ships or pile driving, or those from marine mammals including seals and dolphins. Lastly, the YUCO-Carrier is offered as an open variant of the YUCO, for users to embed their own sensors or sondes in the wet payload cone. It can be customised to up to 45 cm with variable geometries on request. “As long as you equilibrate properly and make a dedicated nose cone, you can implement as many different payloads as required,” Simon explains. “And as the payload sections have similar power and comms modes they can be swapped without issue.” SeaPlan intelligence Pre-deployment programming and recovery of mission data are performed on the YUCO via wi-fi on the SeaPlan GCS mission planner. The GCS also connects persistently to the YUCO via wi-fi. The YUCO’s computer architecture consists of a main central board, with distributed lower-level boards allocated to different subsystems, including dedicated microprocessors for the INX, the payload and some other parts. This robustness of processing and data handling enables some key capabilities for the end-user. As the YUCO executes programmed waypoints, the operator receives visualisations of not just the AUV’s longitudinal and latitudinal position but also its depth along the programmed route, which is shown in a separate display (consisting of just the y and z axes) below the GCS area map. That allows the user to set geo-fences for the YUCO in terms of depth below waves and altitude over the seabed, with minima and maxima configurable for both. Also, templates for navigational patterns such as spiralled loitering, 3D zigzagging or floating at the surface for gathering data can be dragged and dropped onto or between different waypoints. October/November 2022 | Uncrewed Systems Technology Digest | Seaber YUCO Seaber’s SeaPlan GCS software enables a wide range of intelligent behaviours for navigation, data gathering and recovery during each YUCO mission