Unmanned Aerial System Selection
and Sensor Placement
Research Analysis
Miguel A. Linares
Embry-Riddle Aeronautical
University
Introduction
When designing an unmanned system regardless of its operational domain,
one has to consider a number of factors like the type of power source, payload
capacity, general mission objectives and related sensor types. This study will
focus on the selection and description of two commercially available UAVs as it
pertains to the aerial photography and first-person-view racer applications of
each system. Each of the UAVs selected have been designed primarily to meet
their intended objective. In studying these UAVs and their capabilities, the
design characteristic of “onboard sensor placement” and its impact on system
performance and mission accomplishment will be discussed.
Aerial Photography
UAS
Aerial photography is an industry that
has greatly benefited from the use of small UAVs as it provides an appealing
perspective and proximity that could not be achieved via manned aviation. Due
to this industry’s open acceptance to the technology, manufacturers and
developers have created a wide range of unmanned aerial photography system
designs ranging form those resembling recreational model remote control fixed
and rotary aircraft, to the more popular quadcopter drones.
For this study, the DJI Phantom 4 has
been selected as the ideal unmanned system to achieve optimum professional
grade low altitude aerial photography, regardless of its specific market. This
quadcopter drone has several design improvements that make it ideal for the
task at hand such as its motor locations, imaging stabilization software, and
autonomous flight functions. The motors have been raised from the previous
Phantom 3 UAV meaning they will not come into the top of the image when flying
forward at higher speeds. The Phantom 4 is also very stable in flight enabling
a more stable image with low vibration from the motors. The gimbals enable also
a more stable image. The flight modes that this DJI drone has include position
hovering, tap-to-fly, follow-me, flight path pre-programming and active tracking.
This drone however does have a new feature that few systems out there offer and
that is an obstacle avoidance feature through the use of sonar radar sensors.
The downside of this capability, which enhances the safety of the system while
flying is that the sensors can only detect larger objects in front of the
system. Thus, they are not capable of avoiding obstacles if flying sideways. (4K Stephen,
2016)
Nonetheless, this obstacle avoidance feature is sure to be improved on in the
future.
The system design
places the camera below the system enabling it to capture images through a
great range of angles. However, the landing gear supports are fixed and thus
would obstruct the image at certain angles; a problem easily fixed by facing
the drone forwards or backwards. (Gilbertson,
2016)
The fixed landing struts also serve as a protection to the camera sensor in
case of a crash, which is something that other drones like the Yuneec Typhoon H
would suffer great damage from. The Typhoon H has a retractible gear which
enables unobstructed 360 degree rotation of the camera but at the expense of
exposing the camera to possible damage. (Biggs,
2016)
This system also has a more complicated controller, thus making the system
harder to fly and more difficult to capture footage. (Ulanoff, 2016) The Phantom is also
equipped with dual down-facing cameras that serve as a positional and flying aid
when operating indoors, low to the ground, or outside of GPS signal coverage. The
main camera sensor placed below and at the center of the main body has 12.4
effective megapixels to capture still images as well as shoot 4K video
recording and live stream 720p HD quality video. (DJI , 2016)
FPV Racer UAS
When it comes to FPV drone racing,
there are many systems available for all kinds of skill levels. Racing leagues
like DRL (Drone Racing League) have seen competitors reach speeds of
approximately 85mph from multirotor-type drones. Although the winning and
fastest drones are all self-builds and have been heavily modified, there are a
few ready-to-fly (RTF) racing drones available for purchase.
The system chosen in this study for
FPV racing is the Immersion RC Vortex 250 Pro. While this system is considered
RTF out of the box, it is not necessarily for beginners in the drone-flying
arena because of its capabilities and speed. Drones that are more user-friendly
and less expensive in case of a bad crash would include the Hubsan X4 H107D.
However, to win a race, the Vortex is likely the RTF drone of choice. (Nixon, 2016) The Vortex’s design
does enable for a very fast and maneuverable drone. It is a quadcopter with an
X-style frame that carries its components centered so that the system is well balanced,
allowing for maneuvering and returning to stability with less effort from the
motors and thus using less energy extending battery life. A great option of
this system is the ability to adjust the angle of the flight camera up to 45
degrees. This helps specifically for this racing drone due to the incline on
the platform’s body caused when traveling at higher speeds. (Immersion RC, 2016) The Vortex has been compared to other
racing drones like the Walkera Furious 320, which can achieve higher speeds of
75mph compared to the Vortex’s 65mph. However, the Walkera is also bigger,
heavier, less sturdy, and less agile when performing in a tight circuit. (RT Staff,
2016)
The Vortex is highly durable and could survive a crash to fly another day.
Furthermore, the placement of its antenna high and centralized on top of its
body enables for a reliable connection with the controller despite high angles
of bank.
Conclusion
The
world of small UAS has been growing and continues to grow encompassing a wide
range of audience users. From enthusiast photographers or commercial film
producers using the Phantom 4 in the aerial photography industry, to the
beginner recreational drone pilot or the expert FPV racer and systems
modification builder using the Vortex 250 to win 1st place, there is
a place for everyone in the world of small UAS.
References
4K Stephen. (2016, April 22). DJI Phantom 4 Review
– 4K UHD UAV Camera Drone Quadcopter. Retrieved from 4K:
http://4k.com/drones/dji-phantom-4-review-4k-uhd-uav-camera-drone-quadcopter/
Biggs, J. (2016, August 8). The
massive Yuneec Typhoon H is pure aerial video magic. Retrieved from
TechCrunch:
https://techcrunch.com/2016/08/08/the-massive-yuneec-typhoon-h-is-pure-aerial-video-magic/
DJI . (2016, September 25). Phantom 4
Info. Retrieved from DJI: https://www.dji.com/phantom-4/info
Gilbertson, S. (2016, April 22). Review:
DJI Phantom 4. Retrieved from Wired:
https://www.wired.com/2016/04/review-dji-phantom-4/
Immersion RC. (2016). Vortex 250 Pro.
Retrieved September 26, 2016, from Immersion RC: Real Virtuality: http://www.immersionrc.com/fpv-products/vortex-250-pro/
Nixon, A. (2016, July 1). Racing Drone
Buyers Guide. Retrieved from Best Drone for the Job:
http://bestdroneforthejob.com/drones-for-fun/racing-drone-buyers-guide-2/
RT Staff. (2016, February 24). Walkera
Furious 320 vs. Blade Vortex 250 Pro: Which Racing Drone is Best?
Retrieved from Robotics Trends:
http://www.roboticstrends.com/article/walkera_furious_320_vs_blade_vortex_250_pro_which_racing_drone_is_best
Ulanoff, L. (2016, July 7). Yuneec
Typhoon H drone is full of awesome power and frustrating complexity.
Retrieved from Mashable:
http://mashable.com/2016/07/07/yuneec-typhoon-h-drone-review/#NDrfGYsG25qH
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