Unmanned Systems Technology 028 | ecoSUB Robotics AUVs I ECUs focus I Space vehicles insight I AMZ Driverless gotthard I InterDrone 2019 report I ATI WAM 167-BB I Video systems focus I Aerdron HL4 Herculift

74 Future developments In addition to further testing, to potentially increase the maximum power rating and gauge the engine’s performance with a prop mounted, the company is turning towards hybridisation. “We’re particularly interested in developing an independent parallel hybrid of the WAM-167BB,” Newton says. “For example, if you combined the engine’s output with an electric motor, two to 10 minutes’ of extreme power output could be achieved. “In addition to the obvious redundancy, that could give a far more powerful escape capability, which is key for some users. You might break a motor or severely damage a piston along the way, but you’ll still have your UAV and engine back at the shop in largely one piece.” ATI also foresees such a system’s redundancy enabling successful returns to base even with one of the propulsion units out of action. Newton and Franklin see a parallel hybrid system as helping commercial aircraft maintain clean air and quiet operation around airports and urban areas. If approach, take-off and landing can be conducted under electric power, the diesel engine can be used after clearing 8 km of the emissions-restricted area (depending on what distance regulations require) for propulsion and driving the generator to recharge the battery. With a simplified, lightweight base design, ATI will be able to modify, upgrade and repurpose the WAM engine for a range of potential uses and innovations well into the future. October/November 2019 | Unmanned Systems Technology Dossier | Apple Tree Innovation WAM-167BB WAM-167BB Two-stroke four-cylinder reciprocating engine Twin charged with intercooler Diesel, heavy fuel, biodiesel Weight: 118 kg Size: 914 by 657 x 528 mm Maximum continuous power output: 100 kW Maximum continuous torque: 375 Nm Bore x stroke: 97.5 x 100 mm = 2986 cc (746.6 cc per cylinder) Compression ratio, undisclosed Compression ignition, pre-chamber Indirect injection Maximum rpm, 2750 Some key suppliers to the WAM-167BB Crankshaft: Arrow Precision Engineering Crankshaft: Farndon Engineering Con rods: Arrow Precision Engineering Con rods: Farndon Engineering CNC machining: CNC Solutions Camshafts: Kent Cams Camshafts: Newman Cams Camshafts: Retro Track & Air Valves: G&S Valves Aluminium castings: GPD Developments Aluminium castings: Aeromet Group Cylinder liners: Laystall Propeller governor: Jihostroj Propeller governor: MT Propeller CAD/FEA: SolidWorks CAD/FEA: Advanced Analysis Specifications A water pump at the back of the WAM- 167BB drives the water-antifreeze mixture for cooling the pre-combustion chambers, fuel injectors, cylinders and other areas of thermal concern across the engine