Issue 45 | Uncrewed Systems Technology Aug/Sept 2022 Tidewie USV Tupan | Performance monitoring | Bayonet 350 | UAVs insight | Xponential 2022 | ULPower UL350i and UL350iHPS | Elroy Air Chaparral | Gimbals | Clogworks Dark Matter

76 crashworthiness might not be needed, so the fabric can be dispensed with to save cost and weight. The polyurethane alone enables a highly elastic and user- friendly fuel bladder, particularly during integration or maintenance. “Our lead times are around 4-5 weeks,” he said. “We try to complete the design phase back and forth with customers in about a week or two, then we go through the production process. “We generally encourage customers to give us a CAD model of the cavity they want to put the fuel bladder in, then we take that and translate it into either flat patterns for the fabric or use the CAD model to 3D-print a vacuum-forming toolset that allows us to manufacture the bladder to the exact shape.” High Eye was displaying its latest helicopter UAV, the Airboxer, which runs on an 80 cc two-stroke engine to achieve an endurance of 3-4 hours depending on payload and weather conditions. “We buy the two-cylinder, fuel-injected power unit from Zenoah before stripping it down, making our own modifications and installing some original parts for thermal management and such,” said Jesse La Porte. “We’ve done considerable testing of the system, including FAR33 endurance testing, running it on jet fuel and designing it with IP67 ruggedness and EMI shielding to appeal to maritime users in particular.” Notably, EMI frequencies of 1 MHz to 18 GHz and field strengths of 200 V/m have no impact on the Airboxer’s operations. The aircraft can also tolerate winds of up to 25 knots during take-off and landing, as well as moderate amounts of rain, snow and hail, with recommended operating limits in temperatures of -20 C to +45 C. The system has a standard data link range of around 50 km, it can carry up to 7 kg of payload within a MTOW of 32 kg, and its top speed is 70 knots. With a 2 kg payload, it can cruise at 30 knots for an endurance of slightly above 3 hours. Its powertrain uses main and tail rotor gearboxes based on over-dimensioned gearsets and titanium shafts, which are enclosed and environmentally sealed with permanent lubrication. Both the gearboxes and the rotors are validated to a TBO of 1000 hours in standard operating conditions. Doosan Mobility Innovations showcased many solutions in its ever- expanding range of products designed around hydrogen-electric mobility for autonomous vehicles. One of the most notable was the DM15, its most SWaP- optimised PEM fuel cell system to date. “The DM15 is a turnkey fuel cell solution with a 1.4 kW rated power output aimed principally at fixed-wing UAVs,” said Soonsuk Roh. “In our previous fuel cell powerpack solution, the DP30M2S, the hydrogen tank was included inside the product enclosure, but with the DM15 the tank is separate. That’s so that UAV manufacturers can install their hydrogen storage in their fuselage in the location and form factor that makes the most sense to them in terms of volume constraints, weight distribution and so on.” Up to 3 kW of power can be generated August/September 2022 | Uncrewed Systems Technology Doosan says the DM15 is its most SWaP- optimised PEM fuel cell to date Fuel Safe bladders are made largely from a strong fabric with a polyurethane coating The High Eye Airboxer has an IP67 rating and EMI shielding