Hello, this is my design for Airbus Cargo Drone Challenge.
DroneX was designed with efficiency in mind. My major concern is the fact, that having big wings while the craft is hovering will make it very sensible to the smallest winds. One of the requisites is hover 5 min, with winds up to 10m/s. For that, some simple form to reduce the wing surface is needed.
After dealing with different concepts to reduce the wing surface, I concluded that a retractable wings are needed. A simple design combining a telescopic spar (pneumatically actuated) with ribs, and flexible skin (parachute fabric), is enought light and resistant to do the job.
- DroneX can travel 100km with 5kg cargo.
- Designed with FLZ_Vortex and XFLR5
1. “Keep it super simple”:
a) Quad configuration: Most simple configuration, less elements, less prone to failure, less weight, extensively tested.
b) Flying wing configuration: One body, one wing, and four tail elements. Minimal elements with simple and symetrical shapes.
c) Tail sitter configuration: No transition flight mecanisms requiered. Less weight, less prone to failure, less elements to program and control.
d) Shared function elements:
i. Forward flight propulsion is achieved with the same motors/propellers used in multicopter mode. In aircraft mode the inferior motors are stopped, and propellers retracted.
ii. Inferior tail landing gear are used for land and takeoff in multicopter mode and aircraft mode.
e) Low parts count: The main body structure and skin are built with less than 15 parts.
2. Keep in mind: An optimized design contains the following:
a) Ease of maintenance:
i. All parts are easily accesible removing the superior and inferior skin parts (less than 20 screws)
ii. Ease of acces: The internal space is big, all internal parts are easy to acces and well spaced. No problem for those technicians with big hands.
iii. Elements with most decay are packed in the external nacelles. These nacelles are atatched to main body throught two screws, So replacing motor, ESC, battery, or propeller is as easy as swaping the nacelle with failure or TBO exahusted for one new, and send the old to overhaul.
b) 20 minutes turnaround between max-distance missions: less than 15 min
i. Land, propellers stopped, disarmed: <10s
ii. Aproximation to the Drone X with 4 fresh charged nacelles, and new cargo (15kg max): 60s
iii. Visual inspection: 240s
iv. Proceed to unload the arrived cargo (push demagnetitzation button while holding the cargo): 60s
v. Proceed to load the new cargo (Hold the cargo in their place and push magnetitzation button): 60s
vi. Remove the screw protection of nacelle 0 and remove the two screws that attatch him to tail 0. Swap the exhausted nacelle with a fresh one, plug in in their position and tighten the screws. Finally put the screws protection again: 90s
vii. Remove the screw protection of nacelle 1 and remove the two screws that attatch him to tail 1. Swap the exhausted nacelle with a fresh one, plug in in their position and tighten the screws. Finally put the screws protection again: 90s
viii. Remove the screw protection of nacelle 2 and remove the two screws that attatch him to tail 2. Swap the exhausted nacelle with a fresh one, plug in in their position and tighten the screws. Finally put the screws protection again: 90s
ix. Remove the screw protection of nacelle 3 and remove the two screws that attatch him to tail 3. Swap the exhausted nacelle with a fresh one, plug in in their position and tighten the screws. Finally put the screws protection again: 90s
x. Preflight check: 60s
xi. Arm, propellers start spinning, takeoff: <15s
c) Swappable batteries: The batteries are included in the external nacelles.
d) Consider the following conditions:
i. -30 to 50: Yes (Electronics included in the ignition kit must be capable of sustain these conditions).
ii. Moderate rain: Yes (The skin makes contact with the structure and vapour seals, creating watertight zones to all neded parts. The cargo is watertight too).
e) Safe operation in all flight states:
3. Human factors and safety provisions:
a) Transportable by two average size pople: It can be transported by one person as a backpack of 25kg.
b) Limit time on ground with rotors spinning: Automatic takeoff and landig will be programed to stay the minimal time in the ground with the propellers spining.
i. Takeoff: <15s
ii. Landing: <10s
c) Modular design for ease of transport:
i. Modular wings (easily atatched with 4 screws for half wing). There will be two versions attatchable. Conventional wings, and retractable wings.
ii. Modular nacelles (easily atached with 2 screws for each one)
d) The aircraft shall be able to be disassembled and transportable. Consider different scenarios of shipping to perhaps even remote places ( van, vessel, aircraft, truck, ISO container etc.).
i. Van: Capable
ii. Vessel: Capable
iii. Aircraft: Capable
iv. Truck: Capable
v. ISO container: Capable
4. Design guideline for your design:
i. May consider a disc loading between 10 kg/m^2 and 50 kg/m^2: Disc loading of 25 kg/m^2.
ii. May consider a wing loading between 10 kg/m^2 and 30 kg/m^2: Wing loading of 10 kg/m^2.
5. Mitigate consequences of failure:
i. Flight termination parachute system included.
ii. Redundant battery system.
6. May consider a landing gear for conventional fixed-wing take-off and landing: This is a working progress. Space and weight reserved for it.
7. Ease of handling: The stability factor is >10% at cruise speed (80km/h). The stall point is 45km/h.
4x Motors: KDE7215XF-135 (565g) 2260g
4x ESC: KDEXF-UAS95HVC (86g) 344g
4x Battery: 16s3p Samsung INR 18650-35E 3500mah (2256g) 9024g
4x Electromagnetic cargo holding: OpenGrab EPM V3 (40g) 160g
24x Propeller Blade: Aeronaut CAM-CARB 18.5x15 (12g) 288g
1x Pneumatic System: Custom brushless radial turbine, with valve system for deliver pressure/vaccumm (inflate/deflate telescopic main spar and other actuators) 350g
1x Structure: Custom made structure with lasercut plates of CF-Nomex, and some mechanized aluminium parts.
1x Skin top: Vacuum formed
1x Skin bottom: Vacuum formed
2x Ventral cargo doors: Vacuum formed
2x Tail doors: Vacuum formed
2x Flight termination system doors: Vacuum formed
4x Tail nacelles: Vacum formed skin / CF tube and plates structure