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

88 Report | AUVSI Xponential 2021 ultra-reliable, encrypted, high-throughput and highly SWaP-optimised mesh data link,” said Amol Parikh. “It operates at six frequency bands, from 1625 to 2500 MHz [which are also known as the M1 to M6 Federal Bands], providing global coverage in a single radio. Helix was developed for the Blue sUAS programme, which was sponsored by the Defense Innovation Unit of the US Department of Defense.” The dual-band Smart Radio Wearable was developed to help connect human operators and handheld GCS devices to private mesh networks. The system comes with a built-in wi-fi hotspot to simplify connecting tablets and smartphones to networks of unmanned vehicles over the internet. “It has integrated antennas, although it can also accept high-gain antennas, and it can also accept any power source, such as a portable battery bank,” Parikh added. “That, and the wi-fi hotspot, free the tablet from having to physically connect to this smartphone-sized radio, reducing weight and cord management. “We are working with some customers on some interesting applications for both of the radios. For example, one is multi-casting a UAV’s video stream to numerous interested parties who are spread out at different distances from the operator, using a combination of the Wearable and a smartphone.” Physical-Logic unveiled its new 50 g MAXL-CL-3050 and 70 g MAXL-CL-3070 closed-loop MEMS accelerometers, part of its new family of MAXL-CL-3000 products. The company says they are the only available MEMS systems with comparable performance to electromechanical (force rebalance) accelerometers while retaining the former type’s SWaP-C grades. “The MAXL-CL-3000 family’s performance characteristics include one year of bias repeatability of less than 0.5 m g – with less than 0.25 m g in typical operations – and a temperature residual error below 70 µ g , Aviram Feingold explained. “On top of that, we can achieve a vibration rectification error below 25 µ g / √ Hz, with typical results within 10 µ g / √ Hz, and a scale factor linearity error below 300 ppm with standard results below 100 ppm.” Charges in accelerometers’ Si/SiO 2 interfaces and SiO 2 layers typically affect the sensors’ performance after being switched on and under various environmental conditions. Also, temperature variations, ageing and previous circuit conditions can affect the magnitude of charge build-up in MEMS accelerometers, while high feedback voltages can increase charge build-up and result in high scale-factor and bias errors. Physical-Logic therefore sought to eliminate measurement errors in the sensor by minimising charging effects on the MEMS device’s surfaces and interfaces between the device layers. In 2019, the company began work on minimising the charge accumulation occurring on the devices’ interfaces, with an eye towards making the device surfaces as smooth as possible and reducing native growth of SiO 2 layers. In parallel, the r&d team introduced a new charge release algorithm module for the sensors’ electronics. This provides a varying voltage that helps eliminate charge build-ups on the capacitors and other MEMS electrode surfaces. To make the MAXL-CL-3050 and 3070 production-ready, the company took a number of validation steps. These included analysing performance data accumulated on upwards of 100 prototype MAXL-CL-3000s, and accelerated lifetime testing including a year of storage at 60 C to simulate 11 years of storage at room temperature, with temperature cycles from -40 C to +85 C performed once a month. UAV Factory has released the Penguin C VTOL, a UAV based on the design of the Penguin C Mk 2 but with the addition of the company’s patented Aeroflow VTOL boom technology in the airframe. The Aeroflow technology consists of servo-actuated hoods that automatically and fully enclose the vertical lifting propellers while the vehicle is in horizontal flight. This effectively eliminates the parasitic drag that such propellers typically impart on such vehicles. “Aeroflow enables a 20% increase in flight endurance compared with typical twin-boom VTOL-transitioning UAVs,” explained Konstantins Popiks. “That means the Penguin C VTOL October/November 2021 | Unmanned Systems Technology Physical-Logic’s latest closed-loop MEMS accelerometers