Tech Briefs Magazine - August 2023 - MD-27

Biomimetic " Myriapod " Robot Relies on Dynamic
Instability to Navigate
A new centipede-like robot shows how its motion can be switched from straight and curved walking,
which may assist with search and rescue operations or planetary exploration.
Osaka University, Suita, Japan
A
team of researchers from the
Department of Mechanical Science
and Bioengineering at Osaka University
have invented a new kind of walking
robot that takes advantage of dynamic
instability to navigate. By changing the
flexibility of the couplings, the robot
can be made to turn without the need
for complex computational control systems.
This work may assist the creation
of rescue robots that are able to traverse
uneven terrain.
Most animals on Earth have evolved a
robust locomotion system using legs that
provides them with a high degree of
mobility over a wide range of environments.
Somewhat disappointingly, engineers
who have attempted to replicate
this approach have often found that
legged robots are surprisingly fragile.
The breakdown of even one leg due to
the repeated stress can severely limit the
ability of these robots to function.
In addition, controlling a large number
of joints so the robot can transverse
complex environments requires a lot of
computer power. Improvements in this
design would be extremely useful for
building autonomous or
AB
Motor
Spring
Nut
Screw
Body-axis joint
C
Nut
Motor
Screw
Body-axis joint
Motor
Spring
Body-axis joint
Screw (back side)
Myriapod robot (A) and Variable body-axis flexibility mechanism (B. Front view, C. Top view, D. Schematics
of top view). (Image: 2023, Aoi et al., Soft Robotics)
semi-autonomous
robots that could act as exploration
or rescue vehicles.
Now, investigators from Osaka
University have developed a biomimetic
" myriapod " robot that takes advantage of a
natural instability that can convert straight
walking into curved motion. In a study
published recently in Soft Robotics, researchers
from Osaka University describe
their robot, which consists of six segments
(with two legs connected to each segment)
and flexible joints. Using an adjustable
screw, the flexibility of the couplings
can be modified with motors during the
walking motion.
The researchers showed that increasing
the flexibility of the joints led to a
situation called a " pitchfork bifurcation, "
in which straight walking becomes unstable.
Instead, the robot transitions to
walking in a curved pattern, either to
Motion Design, August 2023
the right or to the left. Normally, engineers
would try to avoid creating instabilities.
However, making controlled use
of them can enable efficient maneuverability.
" We were inspired by the ability
of certain extremely agile insects that
allows them to control the dynamic instability
in their own motion to induce
quick movement changes, " said Shinya
Aoi, an author of the study. Because this
approach does not directly steer the
movement of the body axis, but rather
controls the flexibility, it can greatly reduce
both the computational complexity
as well as the energy requirements.
The team tested the robot's ability to
reach specific locations and found that
it could navigate by taking curved paths
toward targets. " We can foresee applications
in a wide variety of scenarios, such
as search and rescue, working in hazardous
environments or exploration on
other planets, " said Mau Adachi, another
study author. Future versions may
include additional segments and control
mechanisms. " We hope that our research
can make it easier for people to
show robots what they prefer, " said
Nemlekar. " By helping each person in
their preferred way, robots can reduce
their work, save time and even build
trust with them. "
For
instance,
imagine you're assembling
a piece of furniture at home, but
you're not particularly handy and struggle
with the task. A robot that has been
trained to predict your preferences could
provide you with the necessary tools and
parts ahead of time, making the assembly
process easier.
This technology could also be useful in
industrial settings where workers are
tasked with assembling products on a
mass scale, saving time and reducing the
risk of injury or accidents. Additionally, it
could help persons with disabilities or
limited mobility to more easily assemble
products and maintain independence.
For more information, contact Aoi
Shinya at resou.osaka-u.ac.jp/en/contact.
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Spring
Nut
D

http://resou.osaka-u.ac.jp/en/contact

Tech Briefs Magazine - August 2023

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