Uncrewed Systems Technology 044 l Xer Technolgies X12 and X8 l Lidar sensors l Stan UGV l USVs insight l AUVSI Xponential 2022 l Cobra Aero A99H l Accession Class USV l Connectors I Oceanology International 2022

60 Insight | USVs The TriDrone surveys at a speed of 3 knots to enable clear echo sounder data, although depending on its payload it can move at up to 6 knots. Its motor is a BLDC system fitted with a weed guard to prevent blockages, with energy coming from a 16 Ah lithium-polymer battery pack over a 14.8 V bus. Two 120 A ECUs provide redundant electronic control, and navigation is supplied by the end-user’s choice of GNSS (the vehicle is compatible with all brands). “While the TriDrone is currently in a single-beam echo sounder configuration, we are testing the integration of an acoustic Doppler current profiler into the system for conducting river flow calculations during high water events,” Tamplin notes. With specific niche operations being demanded by maritime businesses, Hong Kong-based OceanAlpha has also developed a number of specialised USVs for different environmental monitoring tasks. The ESM30 for instance is its first craft designed especially for sampling water quality. It measures 115 x 80 x 43 cm and moves at up to 2 m/s (4 knots), with up to 3 hours of endurance if a survey speed of 1 m/s is maintained. For additional safety when surveying autonomously in ports, harbours and other potentially congested locations it has a built-in obstacle avoidance capability powered by ultrasonic sensors about its fibreglass and carbon-Kevlar hull, which is designed with a catamaran shape for high stability. It is compatible with numerous sensor probes from different brands, enabling it to monitor parameters such as pH, dissolved oxygen, turbidity, conductivity, temperature, oxidation reduction potential, chlorophyll and blue-green algae growth. Samples are collected in four onboard bottles of around 1.8 litres each from 0.5 m below the waterline before being measured; sampling can also be performed autonomously at preset waypoints as pre-programmed in the mission planning software. “Water quality graphical reports can then be automatically generated from real-time survey data transmitted from the USV’s antennas to the GCS, either for routine monitoring or for emergency responses to pollution incidents in water supplies, aquaculture, municipal administration and environmentally protected areas,” according to Ran Zhang, OceanAlpha’s general manager. More recently, OceanAlpha has also introduced its ME120 flow injection monitoring USV, which integrates a multi- parameter online water quality analyser and a flow injection analysis system for measuring ammonia, nitrogen and total phosphorus levels. Its vessels have been used to investigate and prevent illegal river sewage discharges in Taizhou, Jiangsu province, as well as with multi-beam and sidescan sonar mapping systems. Lakes and harbours CEiiA was founded to support efforts across Portugal’s automotive industry. These days however, it has diversified its portfolio to include maritime autonomy, unveiling its Orca USV at Oceanology International 2022 in London. The Orca is a hybrid-electric platform built on a catamaran hull measuring 3.4 m long, 2.7 m tall and 1.7 m wide. Its total weight is 450 kg, with a 100 kg payload capacity. Helder Oliveira, head of electronics and embedded systems at CEiiA, says, “Orca’s development started in 2017, with the first concept of the vehicle being focused on bathymetry surveying missions. Following a USV market evaluation, we decided to expand the mission requirements, rendering the Orca to become a multi-purpose platform.” With the physical structure largely defined by 2018, CEiiA then started onboard software development to enable the Orca to navigate autonomously. A year later, the first sea trials were performed to validate its behaviour, control and navigation. The system can operate for up to 24 hours from launch to recovery, with a top speed of 5 knots thanks to its two electric thrusters outputting a collective 12 bhp at peak power. Data gathered from its payloads (as well as vehicle control and health information) during this time can be communicated over LTE links, wi-fi or cellular SMS updates for individual alerts. “To achieve a payload capability of 100 kg on a vessel less than 4 m in length, and to operate such a sensor June/July 2022 | Uncrewed Systems Technology The ESM30 is engineered with several litres of sampling bottles for water quality measurements (Courtesy of OceanAlpha)