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10 Platform one FlyFocus has developed a high- power tethered UAV that is also detachable to give a combination of operating modes for surveillance applications (writes Nick Flaherty). The CableGuard can hover at altitudes of 70 m indefinitely using a 5 kW power supply to drive eight motors. A remote command detaches the tether cable, allowing the UAV to fly freely at up to 60 kph to track a suspicious object for up to 30 minutes. The cable furls automatically as it detaches. The system uses isolated, regulated DC- DC converters from Vicor to supply the UAV’s motors and electronics from a 400 VDC cable and to keep the batteries fully charged and ready for the UAV to detach. Using a high voltage for the tether reduces the cable current and I2R losses, and means a lighter cable with a smaller diameter can be used, which gives the higher operating altitude. The higher power also allows cooled thermal cameras or larger zoom systems to be used. However, this requires an efficient conversion of the 400 VDC source to the 36 V operating voltage of the motors, which is provided by the Vicor ceramic DC module. This allows eight 600 W DC- DC converter modules to be packed into a limited-size pod under the UAV, with just two heatsinks or fans. In tethered mode, the UAV can carry out surveillance virtually indefinitely, with only occasional landings for maintenance inspections. When it untethers for free flight, onboard batteries seamlessly take over its power supply, allowing up to 30 minutes’ flight with a single daylight camera payload or 20 minutes with a dual thermal-plus- daylight camera. With eight motors, it can safely land even if two are disabled. The cameras provided are a full HD type with 10x optical zoom and 4x digital zoom, and a night vision IR 640p camera with 4x digital zoom. Control of the UAV is via a fibre optic cable alongside the power cable in the tether, or via a 128-bit ASES encrypted radio link when detached. Tethering is just an option Airborne vehicles December/January 2021 | Unmanned Systems Technology Gladiator Technologies has enhanced its Velox high-speed data sampling software to boost the performance of its compact inertial measurement unit designs (writes Nick Flaherty). “We have released SX2 versions of our LandMark005 IMU, LandMark007 High Dynamics IMU and G300D gyroscope with an improved performance engine using our high-speed data processing Velox technology,” said Eric Yates at Gladiator. The low-noise sensors measure 9.8 cm 3 . (0.6 cu in) and use the Velox software to enable the use of cost-effective sensors. The updated Velox software gives the SX2 IMUs an improved angle random walk of 0.002 º /s/ √ Hz, as well as improved bias stability and repeatability, and a 10 kHz output with 600 Hz bandwidth. The improvements to the software to reduce the latency and phase lag enable a data transfer speed of 7.5 mBaud and less than 180 µs of delay on the digital signal. “Velox has made further improvements to further reduce the digital latency and phase lag,” said Yates. “Customers will have the option to enable the Velox features most suitable to their application.” IMU data sampler boost Navigation The CableGuard’s 400 V tether can be detached to allow the UAV to track objects for up to 30 minutes