Unmanned Systems Technology 033 l SubSeaSail Gen6 USSV l Servo actuators focus l UAVs insight l Farnborough 2020 update l Transforma XDBOT l Strange Development REVolution l Radio telemetry focus

52 Insight | UAVs in the sky, or for reliable logistics, with a flexible payload and a long flight time for the weight being carried. “If you want to put a heavy Lidar on it, that’s fine too. We also recently tested a long-range acoustic device, which can be used for crowd control or for disseminating lifesaving information to large groups of people on the ground.” To achieve this payload flexibility, the MK4-R has been designed to maximise its payload capacity versus its empty weight. To that end, Periscope has made design choices in terms of its propeller design, batteries, ESCs and several other factors that remain proprietary, to produce an aircraft that can carry more than double its own weight. “In January we competed in a heavy-lift tactical resupply competition for the US Marine Corps,” McCarter recounts. “We turned up to that competition with a small carry-case, compared to the giant trucks everyone else’s UAVs needed, and we assembled the MK4 and had it ready to launch in five minutes.” The MK4-R is the largest of Periscope’s UAVs, measuring roughly 175 x 169 cm, and weighing 8.6 kg without payload. When carrying 6 lb (2.72 kg) it can fly for up to 30 minutes, and has flown for 12 minutes with 41 lb (18.6 kg); its maximum rated payload is 55 lb. It has a top speed of nearly 129 kph, cruises at just over 56 kph and can operate in winds of up to 64 kph. In addition to various government and military work, the company is looking at other critical services such as firefighting, where it envisions the MK4 providing critical comms relay and situational awareness capabilities to provide dynamic assistance in coordinating wildfire suppression and evacuation efforts. Periscope is also in talks to work with filmmakers and cinematographers to start mounting IMAX cameras on the MK4-R. These cameras, usually costing upwards of $500,000, have typically only been entrusted to fixed-wing or helicopter-type aircraft, owing to their past dominance in payload-carrying capability. Cinematography Film production cameras remain one of the most expensive varieties of video- capture equipment, and very few UAVs are trusted to carry them safely. The Freefly Alta X quadcopter ranks among the leaders in this field. It can carry 35 lb (15.88 kg) for 11 minutes, and its rotor booms are stiffened with foldable struts that reduce vibration from the motors to the hub and payload. To customise the autonomy and navigation according to the required angles, speeds and routes needed, Freefly has begun integrating the PX4 autopilot stack from Auterion into the UAV. “The Alta X has a unique motor design,” says Kevin Sartori, co-founder of Auterion. “It is almost like a swashplate, and it helps to reduce vibration, improving cinematic picture quality and the longevity of onboard systems. “To help in that regard, the Auterion Enterprise PX4 stack includes the UAV- CAN protocol for motor control response, as well as the newly created open Pixhawk Payload Bus standard to enable Freefly and other users to integrate and hot-swap a wide array of cameras. At the same time, component manufacturers can easily build payloads that are compatible with multiple vehicles. “We have other partners in the US who are developing new heavy-lift UAVs to work in search & rescue, infrastructure inspection, mapping and other applications requiring heavy, high-power camera payloads – and incorporating our new Skynode autopilot and companion computer system to be unveiled later this year.” Summary Designing for heavy lift is a problem that has many different solutions, and there is no single ‘best’ one. UAV manufacturers can cut hull weight, improve hull aerodynamics, install new motors, design a more suitable propeller, and mix in a host of other tried methods and new design theories and technologies. With so many engineering techniques to try out, multi-copters, helicopters and fixed-wing UAVs alike are all diversifying into countless shapes, to better optimise them for carrying more weight for their intended missions, rather than standardising around a handful of hull and powertrain architectures. As end-users guide UAVs in these different directions, component suppliers can be expected to follow suit. They will offer wider ranges of systems and features for navigation, propulsion and connectivity, as well as other products to suit the different breeds of unmanned aircraft that will emerge. August/September 2020 | Unmanned Systems Technology Periscope Aviation’s MK4-R UAV being presented to the US Marine Corps in early 2020 (Courtesy of Chartis Federal)