D3: fixed-wing UAV with 3h endurance and 3m wingspan
D3 is a turnkey unmanned aerial system (UAS). It consists of fully autonomous and highly modular electric glider, integrated autopilot, and ground control software. D3 is ready to fly out-of-the box with minimal training similar to the widely spread consumer multirotor drones.
The main D3 advantage is flight time up to 3 hours with an off-the-shelf 10Ah LiPo battery. In other words, six times longer than a typical multicopter flight of 30 minutes. Additionally, the D3 can take advantage of any local thermals and maintain or even gain altitude without the help of its electric motor. Therefore, the D3 can scan more area and cover longer distance than any multicopter while maintaining a cruise speed of 55km/h.
Applications
Research, Development and Education
D3 is great development airframe for any R&D or educational organization. We have been using the D3 to develop our electronics and software for more than 3 years and continue to improve it.
- D3 is fully operational out-of-the-box . No configuration is required.
- Learn 20% of the features, get 80% of the job done: perform autonomous takeoff, navigate GPS waypoints and land with parachute after watching 20 minute video tutorial.
- Our Raspberry Pi based autopilot allows integration of any custom application. Just upload the executable per sftp and start it per ssh.
- All telemetry data are available per UDP API. Just open a socket with a 3 line snippet and your application will have real time GPS coordinates, velocity, IMU data, etc.
- Two fuselage options, two wing configurations, and two battery capacities provide a great range of payload capabilities, endurance and cruise speeds to fit your application.
- What if the Raspberry Pi has no driver for you sensor? No problem! Our autopilot app can work on any Linux/Windows system that can fit onboard since all real-time computations run on a dedicated MCU board.
- D3 is easy to repair. In R&D accidents are almost unavoidable. We can repair any damaged airframe part in our workshop. Alternatively, we can sent replacement parts at a fraction of the total system’s price.
UAV D3 with optional 2.3m wingspan
D3 with standard 10Ah battery for 3h endurance
Surveying
Surveying with fixed-wing drone should be as easy as with a quadcopter.
Here is how we managed to achieve it:
- D3 supports the 24MP Sony Alpha a5100 by default. The high resolution enables flights from higher altitudes and better yield per flight.
- Hand launch is just as easy as vertical takeoff. Only one thing to remember: throw against the wind direction. The rest is fully autonomous.
- Once D3 is in the air it is the same as with quadrotor: survey the preselected field area and take photos periodically.
- Parachute landing instead of vertical landing. Before landing check the wind direction and if anything lies in the landing path. If OK, press “Open Parachute”.
- Once on the ground, use your favorite software such as Pix4D to process the geotagged pictures.
- With 3 off-the-shelf batteries you can fly 24/7. We use only standard LiPo batteries that can be exchanged in the field. You can charge two batteries in the car while you fly with the third one.
Customization
We develop, build and test every part of the D3 in-house including the software and electronics. As a result, we can customize every aspect of the system.
If your payload seems too bulky or too heavy for the D3 send us your requirements anyway. We will check if we can modify the D3 fuselage or propulsion. If it is not possible then we will offer you a feasible solution based on the D5 or D7 airframes. Alternatively, we will create a completely new technical concept.
Reliability and Safety
Design & Technology
D3 can maintain level flight with minimal energy consumption. The main reason is its high aerodynamic efficiency (L/D ratio). The following elements contribute to the high lift-to-drag ratio of 15:
- High aspect ratio wing: 3m wingspan to 0.2m chord
- Optimized aerodynamic design for low drag
- High surface quality due to vacuum carbon fiber technology
Polished carbon surface of the left wing section and winglet
Having a single BLDC motor onboard instead of four has big advantages:
- Less overall weight for the same power output: one 700W BLDC weighs less than four 175W motors. Additionally, we have only 1/4 of the ESCs, cables, propellers, connectors, etc.
- Greater propeller efficiency for the same power output: a single propeller with bigger diameter is more efficient than 4 smaller propellers
- Less heat dissipation and electrical losses for the same power output: less BLDC copper coils, ESC transistors and cables.
The diameter, airfoils and RPM range of the propeller are selected for high efficiency.
CAD model of highly efficient propeller optimized for D3
Furthermore, the optimal operating point of 2900 RPM reduces the noise. As a result, the D3 is barely detectable by human ear above 50m AGL (170ft) and virtually undetectable above 100m AGL (340ft).
The D3 airframe is extremely light and sturdy. Each part is made of multilayer carbon fiber binded with epoxy resin. All carbon components are made in-house following strict quality assurance process. Interestingly, we use 14 custom made molds for the D3.
The full control of our manufacturing allows us to continuously improve our technology. The added bonus is that we can experiment with new techniques and materials. As a result, our drones get lighter and their endurance increases. And finally, the productivity i.e. yield per flight improves.
Specification Overview
| Wingspan | 2.32m .. 3m | 7.6ft .. 10ft |
| Length | 1.35m | 4.44ft |
| MTOW | 4kg | 8.8lb |
| Payload | 0.8kg | 1.7lb |
| Endurance | 2h .. 4h | |
| Propeller | 13″x10″ | |
| Economic speed | 55km/h | 30kn |
| Maximum speed | 75km/h | 40kn |
| Minimum speed | 25km/h | 13kn |
| Operational range | 3km .. 30km | 1.6NM .. 16NM |
| Propulsion | 700W BLDC | |
| Battery Type | 4S LiPo, 16V | |
| Battery Capacity | 10Ah .. 20Ah |
