Issue 41 Unmanned Systems Technology December/January 2022 PteroDynamics X-P4 l Sense & avoid l 4Front Robotics Cricket l Autonomous transport l NWFC-1500 fuel cell l DroneX report l OceanScout I Composites I DSEI 2021 report

80 the pitch motor, adjusting the weight to correct the angle. In terms of endurance, Hefring Engineering’s objective is to demonstrate the OceanScout’s ability to operate at sea for as long as 5-6 months, although Ordonez points out that the effective endurance will depend on both the sensor applications and the mission design. More than 1.2 kWh of energy stored in its battery pack is enough to support the glider’s propulsion, control, sensor operation, data gathering and comms for months in its current state of development. The existing batteries are not rechargeable, but rechargeable lithium-ion batteries are under development, he says. Developing a vehicle with performance comparable to that achieved by larger, more conventional gliders but with far less complication in terms of operation and maintenance has required close attention to detail, Ordonez notes. “For instance, our battery-change method requires only the separation of one section and one connector, and our piloting software offers intuitive controls and straightforward graphical layouts,” he says. He stresses that Hefring Engineering’s approach to affordability has been through addressing the total cost of ownership, including the vehicle itself and its operation. “Through rigorous engineering and testing, we have optimised each component for durability and to reduce size and, as a result, the interior space used,” Ordonez says. The focus on purpose-built vehicles rather than offering an a la carte approach to users is also driven by affordability. “No user group needs everything, so why drive price and complexity up for one by catering to the specs of another?” Ordonez says. “You also add cost in the way of integration time, either for the user or the manufacturer, if each glider has individual considerations for myriad combinations of onboard electronics working together to produce high-quality data. “In the end, from a customer perspective, the product is the data not the machine. By examining the use case and optimising the vehicle for it, we can reduce cost and give the user exactly what they need – no more, no less – to get that valuable data.” Multi-glider operations The OceanScout’s control software and user interface are designed to perform multi-vehicle missions in which ocean features can be measured in tight transects and on wide spatial scales. Such multi-glider missions are managed by web-based piloting software and a user interface that includes mission planning and data visualisation features that are designed to be sufficiently intuitive for the pilot to keep track of all the gliders’ progress without being overwhelmed, even though each one has to be commanded individually. “The key is in the interface design, which includes a clean, organised layout and simple mission command execution,” Ordonez notes. The next big step in control software development is to enable coordinated mission commands to be sent to and executed by multiple gliders, creating a swarming capability that Ordonez refers to as fleet-controlled flight. “While this future development might enable a number of innovative use cases, our simplified multi- vehicle mission planning is already a force multiplier for individual pilots,” he says. The principal comms bearers are the Iridium satcom network and wi-fi. The former is for long-range commands, monitoring and some data retrieval, while the latter is for more bandwidth-intensive ‘housekeeping’ tasks such as software updates. When connected to the glider locally, Ordonez explains, its operator interacts with its main computer through an interface resembling a web page. This interface enables numerous actions including motor function tests, rapid data download and compass calibration. The OceanScout’s lighting systems, of which there are two, are also part of the comms and location systems. A strobe light integrated into the antenna aids in offshore recoveries, while an LED system indicates the glider’s status to the operator on the support vessel or ashore. “The user will know the glider state without having to consult their laptop, something that is especially useful for shore pilots controlling the glider via Iridium,” Ordonez says. Hefring intends to offer cloud-based services for managing missions and the data gathered in them. That means a glider team does not have to set up a dedicated server in their lab, and that distributed access is provided to all the scientific and navigational data. December/January 2022 | Unmanned Systems Technology The user interface includes course segment displays that show the OceanScout’s sawtooth depth profile and seabed avoidance capability