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

95 and the hub mounts a Cube Orange flight controller that interfaces directly with the fuel cell, to provide the operator with live data on fuel cell power, voltage, hydrogen levels and more. “We contracted a specialist from CubePilot’s open-source network to integrate our data stream into the Ardupilot code,” Douglas-Smith said. He added that Intelligent Energy is collaborating with GKN Aerospace in the H2GEAR programme, which is aimed at running regional and sub-regional zero-emissions commercial flights (19- 100 seats) in the UK by 2026. Existing technological lessons from lightweight UAV fuel cells and evaporative cooling are to be used heavily, as Intelligent Energy aims to develop fuel cells with the power density for these upcoming conventional, eVTOL and eSTOL fuel cell-powered aircraft. Gladiator Technologies attended the show to report on some key performance updates to its MEMS IMUs, including enhancements to signal processing and bandwidth, reductions in noise and latency, adding more feature options, and minimising angular random walk. “These improvements have been implemented in three products: the G300D Triax gyroscope, the Landmark 005 IMU, and the Landmark 007 high-dynamic IMU, the last of which integrates a 2000 º /s rate gyro and a 98 g accelerometer,” said Eric Yates. “For example, through updates to our Velox technology, we can achieve bandwidths up to 600 Hz, whereas most systems only manage 250-300 Hz, and we don’t have to deal with trade-offs such as added noise or filter delay – we maintain around 100 µs of digital delay.” He added that data output rates for the IMU sensors can now reach 10 kHz, an ideal performance level for high stabilisation of tracking gimbals as well as high-speed, highly dynamic aircraft. “About two-thirds of the performance improvements have come from updates to our Velox technology, with about a third being down to adopting the latest improvements in electronics hardware,” Yates said. Thistle Design showcased its latest developments in motion control solutions for high-end defence platforms across land, air and sea, and spoke with us in particular about a reflective encoder it has developed for unmanned vehicles, especially UAVs. The company’s high-performance encoders are used for understanding, with great accuracy, where a vehicle’s servo motors and hence gimbals are pointing – critical information for any long-range cameras or weapons aiming 2 km or further away. Thistle encoders are also used in control surfaces such as guide vanes and in the electric drives on large ships, which need to synchronise their propshafts to minimise cavitation. On the reflective encoder, Kevin Duthie said, “Standard optical sensing systems inside encoders use a sensor on one side, a light source on the other, and a patterned disc in between, to gauge the speed and position of a rotary motor-type system, but our reflective sensor has an internal LED instead, so it has fewer and smaller components, making the encoder smaller and lighter overall. “In fact, it also delivers a step up in performance – up to 22-bit resolution and 18-bit accuracy. “Our prototype reflective encoder weighs about 250 g, whereas an equivalent traditional encoder would typically weigh around 1 kg. Also, ours has a 36 mm diameter compared with 50-55 mm for traditional alternatives.” In addition to delivering a substantial weight saving for traditional use-cases on land, sea and in the air, the SWaP optimisation and performance of Thistle’s next-generation encoders also potentially opens the door to their adoption in unmanned spacecraft such as launch vehicles and satellites. We met with Connect Tech and learned about two new ruggedised embedded computing systems it had on display. “The Sentry-X is built around the Nvidia Jetson AGX Xavier, and has been built, designed and tested to Mil-Std-810G as well as DO-164 and IP67 for ruggedness in harsh environments,” said Rob Callaghan. “It has a removeable computing platform and allows for various I/Os, including 38999 rectangular connectors, Fischer circular connectors, PC-style connectors and others, with high-speed interfaces such as Gigabit Ethernet for sensors, USB 3.0 and 3.1 Gen 2 Type C.” The system also allows for passive cooling, at up to 70 C. The Jetson AGX Xavier computer contains a 512-core Volta GPU, an eight-core ARM v8.2 64-bit CPU, and a seven-way VLIW vision accelerator, among other components. “We’re also presenting our Rudi-AGX embedded system, which is based around the same computing system but with connectivity for up to eight Unmanned Systems Technology | December/January 2022 The sensor in Thistle Design’s reflective encoder features an internal LED The Sentry-X from Connect Tech has been built to military and ruggedness standards