Issue 40 Unmanned Systems Technology October/November 2021 ANYbotics ANYmal D l AI systems focus l Aquatic Drones Phoenix 5 l Space vehicles insight l Sky Eye Rapier X-25 l FlyingBasket FB3 l GCS focus l AUVSI Xponential 2021

51 Aquatic Drones Phoenix 5 | Digest consists of pressurised bulbs that rupture when exposed to the heat of a fire, activating the extinguisher, while the electrical system is based on a set of temperature sensors linked to the PLC. Two separate systems are installed, one for the generator compartment near the stern and the other near the bow to protect the electronics and battery bay. As well as having automatic triggering, both can also be activated remotely. Control station and the cloud On-site control is achieved through a station that is essentially a laptop with two display screens, a dedicated RF link to the vessel and a 4G link to Aquatic Drones’ cloud services. The control station runs mission management software containing all the tools the operator needs to plan, execute, monitor and modify a survey with the UAV to which it is connected. Muhammad Tariq, Aquatic Drones’ software architect, explains that multiple tasks can be planned and prioritised, while individual tasks can be cancelled and new ones added during a survey. The cloud services are accessed through a dashboard that provides a single place from which authorised users anywhere in the world with an internet connection can plan and execute multiple surveys with multiple vessels and select any active survey for monitoring and control. Tariq leads the team responsible for developing the company’s operational software, which is a custom-designed application that incorporates a number of off-the-shelf packages and third-party libraries. Autopilot and autonomy The autopilot is reconfigurable and adjustable for vessels of different dimensions and weights, and is capable of both line and waypoint navigation; it can also adjust the Phoenix 5’s course dynamically in response to inputs from the situational awareness system. GPS/ GNSS systems provide references for fine-tuning the PID controllers. The autopilot also supports safe homing in case of an emergency and controls the vehicle’s loitering capabilities. The situational awareness (SA) system integrates information from a suite of sensors consisting of Lidars, radars, video cameras, an AIS receiver and a forward- looking sonar, all supported by a high- resolution IMU, Tariq explains. Together, they create a 3D virtual representation of the world around the vessel and localise it within that world, enabling the SA system to be used in conjunction with the autopilot for object detection, collision avoidance and survey navigation. Comms The comms link between the vessel and the control station enables real-time monitoring of the control functions, system health and diagnostics, and includes an ultra-low latency video feed that allows steering via radio control if necessary. Another feature is a dedicated RF ‘heartbeat mechanism’ to ensure that a bare minimum control connection is always available. The comms system can accommodate any IP-based network including 4G cellular, wi-fi and marine broadband radio systems, and routes traffic over whichever one is best for a given purpose at the time. For security, all the data and control traffic between the vessel and the control station are protected by 256-bit encryption, with strict TLS handshake mechanisms enforced to ensure comms safety. Internally, many systems talk over EtherCAT, the open real-time Ethernet network developed by Beckhoff for PLC systems, while the sensors have their own network running the NMEA 2000 protocol. However, the PLC remains the brain of the system, and all comms with the base station and the cloud go through it, Tariq says. Testing Testing of the latest iteration of the Phoenix 5, which the company refers to as the production model, began in July. It has a hybrid configuration, the most complex of the variants. “We feel that it is easier to start with the range-extended model, as we have built pure electric versions already that have fewer systems, and we want to test how all the systems work together, how our calculations match up with real-world conditions, how well the cooling system works – the core vessel functionalities,” Hope says. Further testing will cover stability, speed and endurance tests in which power consumption will be logged along with heat build-up in the hull under various conditions. These tests, which follow on from the autonomous sailing tests carried out with a prototype, are scheduled for completion this October. Regarding further developments in the near term, a more advanced and adaptable variable-speed sound velocity profiling winch is in the pipeline, and an automatic sensor deployment system could follow. Unmanned Systems Technology | October/November 2021 Length: 5 m Beam: 2 m Draught: 0.55 m Height: 2.5 m Weight: 1500 kg Survey speed: 5 knots Payload support power: up to 2 kW Some key suppliers Air conditioning: Dometic Diesel generator for HP variant: Whisper Power Fire extinguisher canisters: FirePro Inboard electric motors: WaterWorld Systems Marine mapping software: Teledyne Caris Multi-beam sonar: Teledyne Reson PLC: Beckhoff Specifications