Experiment Research & Electronic Control System Development Of A Small Two-Stroke Heavy-Fuel DISI Engine For Aerial Vehicles

With the development of UAV (unmanned aerial vehicle), small UAVs have been widely used for patrolling, aerial photographing, cargo delivering, investigating and so on. Now gasoline is the main fuel for small UAVs. But in consideration of the fuel security, heavy-fuel which is less possible to self-burn or explode has more potential in the UAV market. Meanwhile, DOD (Department of Defense) requires heavy-fuel for small UAVs. Therefore, heavy-fuel would replace gasoline in the future.Two-stroke spark ignition engines which have simpler structure and bigger power weight ratio are widely used as the propulsion for small UAVs. But most aerial two-stroke engines are still equipped with carburetor or fuel-port-injector. It’s difficult to use heavy-fuel in these engines for that heavy-fuel could not evaporate well with carburetor or fuel port-injector. But direct-injection could solve this problem and cut down fuel consumption greatly.A small DISI (Direct Injection Spark Ignition) two-stroke engine was designed. Based on a two-stroke single cylinder gasoline engine with carburetor, some sub-systems, including combustion system, fuel injection system, ignition system, lubrication system, ISG (integrated generation and starting) system, especially electronic controlling system were designed. Sensors and actuators were chosen. A ECU(electronic control unit) applied to DISI two-stroke engine were designed. The ECU includes signal processing circuit, power management circuit, driver control circuit, communication and fault processing circuit etc. Moreover a control program included main program, signal analysis program, ignition and injection control program, communication and fault processing program were designed. Then a prototype engine and engine experiment system were built. With the experiment system, calibration was conducted to get engine control MAPs. At last, experiment research on original engine and the heavy-fuel engine was given. No.93 gasoline, No.3 aerial kerosene, No.0 diesel were used to test the performance of heavy-fuel engine. The result showed that the heavy-fuel engine performed well with both gasoline and heavy-fuel, and the fuel consumption was cut down greatly.