A Snake-arm robot

A snake-arm robot is a slender hyper-redundant
manipulator. The high number of degrees of
freedom allows the arm to “snake ” along a path
or around an obstacle – hence the name “snake-
arm”.
Definition
Elephant Trunk robotic arm
Snake-arm robots are also described as
continuum robots and elephant’s trunk robots
although these descriptions are restrictive in their
definitions and cannot be applied to all snake-
arm robots.
A continuum robot is a continuously curving
manipulator, much like the arm of an octopus.
An elephant’s trunk robot is a good descriptor
of a continuum robot. This has generally been
associated with whole arm manipulation –
where the entire arm is used to grasp and
manipulate objects, in the same way that an
elephant would pick up a ball.
This is an emerging field and as such there is no
agreement on the best term for this class of
robot.
Snake-arm robots are often used in association
with another device. The function of the other
device is to *introduce the snake-arm into the
confined space. Examples of possible introduction
axes include mounting a snake-arm on a remote
controlled vehicle or an industrial robot or
designing a bespoke a linear actuator. In this
case the shape of the arm is coordinated with the
linear movement of the introduction axis enabling
the arm to follow a path into confined spaces.
Other features which are usually (but not always)
associated with snake-arm robots:
Continuous diameter along the length of the
arm
Self-supporting
Either tendon-driven or pneumatically
controlled in most cases.
A snake-arm robot is not to be confused with a
snakebot which mimics the biomorphic motion of
a snake in order to slither along the ground.
Applications
The ability to reach into confined spaces lends
itself to many applications involving access
problems. The list below is not intended to be an
exhaustive list of possibilities but merely an
indication of where these robots are being used or
developed for use.
Industry
Main article: Industrial robot
Nuclear
Decommissioning [1]
Repair and maintenance [2][3]
Aerospace
Manufacture and assembly: inside wing
boxes, jet engines and ducts.
Surface Preparation: wielding pneumatic
sanders for all stages of surface finishing
prior to final paint application.
Maintenance, Repair and Overhaul
Automotive
Manufacture: Snake-arm robots allow
structures to be assembled in a different
way.
Security and defence
Further information: Bomb disposal robot and
Rescue robot
Bomb disposal and counter terrorism [3]
Search and rescue
Robotic surgery
Main article: Robotic surgery
Endoscopy
Colonoscopy [4]
Neurosurgery [4]
History of Snake-arm robots
Tensor arm manipulator, invented in 1968 by
V.C. Anderson, commonly called the Scripps
Tensor Arm, is a spine-like elephant trunk arm.
Control is via a large number nylon
microfilaments.
ANAT (Articulated Nimble Adaptable Trunk)
AMI-100 , invented in 1997 by Charles
Khairallah, is a modular hyper-redundant
snake-like industrial robot arm.
References
1. ^ "Robot snake created by Bristol
engineers" , Dave Harvey, BBC News Website
( bbc.co.uk ), 27 September 2011
2. ^ "Snaking around in a nuclear jungle" , Rob
Buckingham and Andrew Graham, Int. J.
Industrial Robot, Vol. 32, No. 2, ISSN
0143-991X, 2005, p120-127
3. ^ a b "Snake-arm robots slither forward" ,
Jonathon Fildes, BBC News Website
( bbc.co.uk ), 13 September 2006
4. ^ a b Ingenia
Snake-arm robots are currently being researched
by several major universities:
Cornell University: Student Project team with
goal to design and fabricate a class of robotic
arms that best resemble the strength, fluidity,
precision, and dexterity of a snake
Carnegie Mellon: Research into various hyper-
redundant robots including snake-arms
Clemson : Research into elephant’s trunk
robots
Mississippi State University: Research into
designing, analyzing, and building continuum
robots.
Snake-arm robots are being made commercially
by:
OC Robotics : manufacturing for the aerospace
sector (automated assembly of aircraft),
security (robotics for counter-terrorism),
nuclear (decommissioning and asset
management), and other industries (inspection
and maintenance).