Unmanned Systems Technology 008 | Alti Transition UAS | Ground control systems | Xponential 2016 report | Insitu Orbital N20 | UAVs | Solar power | Oceanology International 2016 report

70 U nmanned aircraft face a continuing engineering challenge of the trade-off between their lifting power and range. Developers of battery-powered rotary systems are looking to increase the range and endurance with hydrogen fuel cells, but face a fundamental limit in the power- to-weight ratio of existing batteries. Providing more power needs larger, heavier batteries, limiting the endurance and lifting power. Larger, diesel-engined craft provide more endurance, from small, 5 m systems up to full helicopter systems that can carry large loads or several people. UAV developers are now converting existing helicopter platforms to make them autonomous by fitting more complex control systems and secure communications links. Fixed-wing designs aim to overcome the endurance challenge, providing longer time in the air and covering a greater distance with higher minimum speeds than rotary craft, putting a strain on the sensors as they have less time to capture data. Developers are therefore looking at new system-wide techniques to provide the coverage that customers are asking for. Using a fleet of battery-powered rotary craft that can autonomously return to a wireless charging point can provide constant coverage for surveillance applications, but require more complex control algorithms. Photography has been one of the major drivers of UAV technology in the past few years, but applications such as those in agriculture are using the same camera technologies to analyse the state of vegetation. This idea is being extended even further with the concept of a swarm of UAVs in the air at the same time with different types of sensors such as electro-optic (EO) cameras for visible light and infrared for detecting changes in the vegetation. PrecisionHawk, for example, has unveiled its latest single-engined fixed- wing platform for carrying complex cameras across fields. The Lancaster 5 has a wingspan of 1.5 m and weighs 2.4 kg with a 1.155 kg payload. With a typical speed of up to 50 kph from the 7000 mAh battery, it can survey an area of 300 acres at a height of 100 m with a flight time of 45 minutes. The comms system provides a link over 2 km for data, and the whole system is controlled by a dual-core processor running the Linux operating system. PrecisionHawk has also teamed up with Insitu, which has its own ScanEagle Flight paths June/July 2016 | Unmanned Systems Technology Nick Flaherty highlights some of the latest developments in unmanned aircraft systems The Lancaster 5 UAV can feed data back from across fields for agricultural analysis (Courtesy of PrecisionHawk)