Issue 54 Uncrewed Sytems Technology Feb/Mar 2024 uWare uOne UUV l Radio and telemetry l Rheinmetall Canada medevacs l UUVs insight DelltaHawk engine l IMU focus l Skygauge in operation l CES 2024 report l Blueflite l Hypersonic flight

52 In operation | Rheinmetall Canada Mission Master medevac functioning as an orphan with their own software and their own GCS. Our software must integrate seamlessly with theirs.” “Overall, I would say 70% of our development work today is on software, with 30% on hardware. The USMC even asked us at one point to integrate Starlink Communications on the Mission Master, which we did on-the-fly so that signals from the UGV operating in Australia could be monitored in real-time from California.” Passive navigation Given apt worries among defence forces that casualties may be vulnerable en route to a collection point (whether transported by UGV or any other means), Rheinmetall Canada has integrated a ‘Blackout Mode’ in the Mission Masters. In this mode, the Lidar stops transmitting to prevent detectable laser pulses being emitted, and the UGVs switch to what Tremblay and Diniz call “passive navigation”. This typically means using only the inertial navigation system, although other sensors such as electrooptical (EO) or infra-red (IR) cameras can be used for obstacle avoidance and localisation (by the UGVs recognising features such as specific trees, structures or geological features to triangulate their position) without significant risk of detection by hostile agents. Passive navigation can also encompass uploading 2D or 3D maps into the Mission Master’s onboard memory. This can be critical for localisation in the event of GNSS denial (including jamming and spoofing attacks), which is an increasingly frequent concern among defence strategists, with the deliberate insertion of errors into GNSS feeds being a common tactic of some military forces. “Even without that, we’ve specifically chosen a very robust inertial measurement unit (IMU) system, such that the Mission Masters can go for quite long distances before distortions and degradations result in any noticeable drift during dead reckoning. “But, again, the SLAM system we’ve developed and embedded means the UGVs can triangulate their positions and recalibrate their INSs if they visually recognise a particular landmark, so it’s even more unlikely they would reach any state of IMU drift,” Tremblay notes. Diniz adds: “We’ve also tested the UGVs in a mine, where receiving GNSS is impossible, and there we used the Lidar to form a detailed map of the mine in real time. And because the UGVs can integrate mesh radios and form a mesh network, once the first UGV created that point cloud-based map, it communicated the information back to the others, so they could navigate and localise themselves while the leader continued to explore the mines and expand the map everyone was using.” Damage downtime When onboard energy runs low or signs of damage are visible, the UGV can be set to follow a soldier back to its base, or a return button on the GCS can be pressed that will trigger the vehicle to automatically backtrack all the way to its deployment point. As with pre-deployment preparations, routine maintenance for the UGVs after and between missions tends to be minimal, even in cold climates where conditions ought to be detrimental to batteries and mechanical components. This is largely attributable to Rheinmetall Canada’s choice of powertrain. “Batteries are expensive and don’t perform well at extremes of temperature, but we’ve worked around that to minimise downtime and the rate at which they need to be replaced,” Diniz says. “The CXT can be left outside at -40 C overnight and will still start the next morning, primarily thanks to the liquid cooling and heating circuit, which enables the diesel engine to heat the batteries to their optimal temperature of 20-25 C.” February/March 2024 | Uncrewed Systems Technology Ongoing trials of the Mission Masters in different locations are critical to finding and resolving edge cases for their autonomy Convoys of UGVs following one another can enable low-complexity autonomy across not only military work but also commercial applications, such as logging trucks