Tech Briefs Magazine - November 2021 - 36

Winner of an HP Workstation
AEROSPACE & DEFENSE
CATEGORY WINNER
HONORABLE MENTIONS
Learning Extreme Flight
Elia Kaufmann and
Antonio Loquercio,
University of Zurich,
Switzerland
This method safely
trains agile flight controllers
in simulation and
deploys them with no fine-tuning on physical quadcopters while
only using onboard sensing and computation. The quadcopter
can perform acrobatic maneuvers in the real world with unprecedented
agility while only relying on onboard sensing and computation.
https://contest.techbriefs.com/2021/entries/11008
HOW
TO KEEP DRONES FLYING WHEN
A MOTOR FAILS, WITHOUT GPS
Sihao Sun, Giovanni Cioffi, Coen de Visser,
and Davide Scaramuzza
University of Zurich
Switzerland
S
afety is critical for autonomous drones. For drones with four
propellers - also known as quadcopters - the failure of
one motor is a big problem. With only three rotors working,
the drone loses stability and inevitably crashes unless an emergency
control strategy sets in. Especially in GPS-denied environments,
a quadrotor with loss of one motor will fast yaw spin,
causing significant position drift, crashing the drone and potentially
harming people on the ground.
The solution is a vision-based control algorithm that saves the
quadrotor after the complete loss of a single motor. Information
from onboard cameras can be used to stabilize the drone and
keep it flying autonomously after one rotor suddenly gives out.
When one rotor fails, the drone begins to spin on itself like
a ballerina. This high-speed rotational motion causes standard
controllers to fail unless the drone has access to very accurate
position measurements. In other words, once it starts spinning,
the drone is no longer able to estimate its position in space and
eventually crashes.
One way to solve this problem is to provide the drone with a
reference position through GPS. But there are many places
where GPS signals are unavailable. The team solved this issue
without relying on GPS, instead using visual information from different
types of onboard cameras. They equipped the quadcopters
with two types of cameras: standard ones, which record
images several times per second at a fixed rate, and event cameras,
which are based on independent pixels that are only activated
when they detect a change in the light that reaches them.
The algorithms combine information from the two sensors
and use it to track the quadrotor's position relative to its surroundings.
This enables the onboard computer to control the
drone as it flies and spins with only three rotors.
For more information, visit
https://contest.techbriefs.com/2021/entries/10909
36
Cov
www.techbriefs.com
ToC
D3 - Control and Deorbit
Spacecraft Without Rockets
Riccardo Bevilacqua, Laurence
H. Fineberg, Dave Guglielmo,
Erik Long, Camilo A. RianoRios,
and Nicolo Marcello
Woodward, Orbotic Systems,
Thousand Oaks, CA
A unique propellant-less ro -
bot can act as part of a spacecraft subsystem to control its orbit
and attitude. The D3 modulates the spacecraft drag force while
controlling orientation and orbital decay. It can be used to control
a satellite constellation, deorbit a satellite, and target the reentry
location.
https://contest.techbriefs.com/2021/entries/11106
Bio-Inspired Multifunctional
Ceramics for Aerospace
Applications
Hamidreza Yazdani
Sarvestani and Behnam
Ashrafi, National Research
Council Canada, Montreal
A fast, simplified, and in -
dustrially scalable fabrication technique is based on laser
machining. Using the technique, a new class of advanced
ceramics based on bio-inspired architectures has been designed
to improve and tune the mechanical response in multi-impact
conditions.
https://contest.techbriefs.com/2021/entries/10992
Project PrObe
Sebastian Bandycki, Piotr Kostek,
Rafal Rotblum, and Janusz
Dobrzanski, Haxtron, Poland
Project prObe designs and develops
an aerial autonomous robotic
platform for extreme and challenging
environments. Capable of highquality
data acquisition activities, the probe features a propulsion
system inside a spherical shape.
https://contest.techbriefs.com/2021/entries/11392
Tech Briefs, November 2021

https://contest.techbriefs.com/2021/entries/11008 https://contest.techbriefs.com/2021/entries/11106 https://contest.techbriefs.com/2021/entries/10992 https://contest.techbriefs.com/2021/entries/11392 https://contest.techbriefs.com/2021/entries/10909 http://www.techbriefs.com http://info.hotims.com/79419-902

Tech Briefs Magazine - November 2021

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