Greetings FPV pilots! I would like to share some experience about model aviation. The prototype is designed and built to serve as a suitable platform for FPV/UAV autonomous flight mission. The design platform is called DLE-JW02-A2
; codename: “The Automaton
”. Besides the amount of payload carrying capability, flight efficiency also becomes the main priority in the design consideration. The FPV gears which consist of CCD camera, AV transmitter, OSD, etc; could be incorporated with the autopilot modules in order to provide aerial view through a ground control station in an autonomous flight mission. To achieve complete information, airspeed sensor, GPS, OSD telemetry and data link Tx/Rx should be included in the autopilot system.
The Automaton consists of 2 wings (upper wing and lower wings) configured in a joined wing layout. The wings’ surface area will provide the desired aspect ratio and suitable wing loading. The wings’ lift production is sufficient for obtaining the payload carrying capability without compensating the model’s maneuverability. Flaps on the upper wing will enable slow-cruise flight capability in addition to function for take-off and landing procedures.
The specification is as follows:
Wingspan : 1520 mm ( 59.84 inch )
Length : 788 mm ( 31.02 inch )
Height : 308 mm ( 12.12 inch )
Estimated A.U.W : 1856 g – 2200 g ( 65.46 oz – 77.60 oz )
Tested Drive system :
- Brushless motor : Turnigy G10, 810kv, 375W
- ESC : Turnigy Trust 55A SBEC
- Propeller : Revox 12x6E
- Servos : Emax ES08MD Digital, Metal Gear servo
- Li-po Batt : Turnigy nano-tech 4S-2200mAh (35C-70C) or Zippy 4S-2200mAh (35C)
Radio Tx/Rx system:
- Futaba T8FG Super, 2.4 GHz transmitter
- Futaba R6028SB, 8ch 2.4 GHz receiver
Design review :
- 409 grams of solid lead is attached to the cockpit to simulate the payload of FPV and autopilot gears; resulting in 1.9kg of A.U.W.
- Airbrake mixing is implemented to preset the flaps and ailevators positions for hand-launch take-off and landing.
- The Automaton is easy for hand-launch take-off, easy for maneuvers, has sufficient lift production for carrying large amount of payload, has lots of thrust for both high and low speed flight.
- Flaps are proved to be effective during the emergency landing procedure; it is also used during a low speed/cruise flight.
- Implement average throttle range of 30% - 60% for efficient flight to increase flight duration.
The maiden flight of the Automaton was a successful one. A 409 grams of solid lead is loaded to the prototype so as to simulate the payload of FPV and autopilot gears.
The tested A.U.W is 1.9 kg and it is easy for take-off and easy to maneuver, even in a windy day. This prototype is expected to be able to reach a payload up to 2.2 kg without decreasing the maneuverability. A co-pilot is required to assist the hand-launch take-off. Flaps offset are pre-set using the airbrake mixing for take-off procedure.
The prototype could easily reach high altitude with the large thrust from the Turnigy G10 with 12x6E prop powered by 4S nano-tech Li-Po batt with 35C constant and 70C burst. The airframe structure strength was tested by implementing average throttle range of 60% - 80% to produce high G-force during maneuver. It flew at high speed and the flaps are disengaged to prevent pitching and gaining altitude.
The flight experience was addictive and the flight lasted for a few minutes before the Li-Po battery had reached its low voltage level. The ESC is programmed by default to automatically reduce the throttle until it kills the throttle; allowing only the servos to operate. Flaps were deployed to maximum position for the emergency landing as motor had stop and did not provide any thrust. Fortunately, the prototype was still at high altitude and had sufficient time to turn and face the headwind for the landing. The Automaton was able to glide down slowly and landed without any damage.
The Li-Po battery was replaced with the fresh one. This time 4S Li-Po batt with 35C was being implemented. The Automaton still easy for take-off, even though the Li-Po batt had no burst high rate C capability. Average throttle range of 30% - 60% provides a slow-cruise flight with a little down flaps setting (approximately 15°
down angle). The flight was more efficient compared to the previous one. The flight was still easy at low speed, but the crosswind had a greater impact on the flight stability.
Here is the video of the event: