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

77 “The fact that LynxOS-178 is a commercial off-the-shelf operating system that has received acceptance for reusability from the FAA for DO-178 certification, and from the EASA, was an important criterion in our selection process.” Ampyx Power developed the autopilot from scratch, and this is one of the main innovations for the PowerPlane; most other elements are available off-the-shelf. The autopilot runs on the latest safety-certified processors from Freescale Semiconductor (which is now part of NXP), and together with LynxOS-178, the control algorithms and software development process allows the system to be certified to aerospace safety standards. The sensors required were determined by a top-down safety analysis, and include an inertial measurement unit, GNSS unit, air data sensor and a tensiometer. This ensures that in all flight phases an accurate input is provided to the onboard computer and that all off- nominal situations can be handled.   The UAV is fitted with two small ducted fans to power the onboard electronics from the wind energy. Lithium-ion batteries are not used, but are still on board to enable a safe landing in case of failure of one of the fans. With this architecture, there is no need for fuel cells, and flight time is limited only by unfavourable wind conditions.  The operational height is maximised at 450 m, and includes margins for safety and counteracting strong gusts of wind. Nominal operations range from 150-350 m, which is within the regulatory flying limits. Ampyx Power says it has fully mapped all regulatory needs for permits to operate and doesn’t consider the maximum height to be an issue, and that the autopilot has no problems with managing a safe landing from any height. Conclusion The start of the first commercial UAV- based delivery service illustrates some of the challenges facing the industry. Fixed-wing craft such as Zip can deliver small packages quickly, and using a parachute for the last stage avoids the need for a vertical take-off rotary craft that other schemes are planning to use. Fixed-wing craft such as Lancaster 5 are also gaining popularity in observation applications such as agriculture, using higher performance hyperspectral cameras. Larger rotary craft such as K-MAX and Matrix are now being used with fully autonomous operation to deliver large loads for the military and for applications such as firefighting. Using swarm algorithms combines small and large rotary platforms to monitor the environment and provide coordinated delivery of equipment and material. Unmanned Systems Technology | June/July 2016 The PowerPlane uses a tether to help generate electricity from the wind (Courtesy of Ampyx Power)