A snake-arm robot is a slender hyper-redundant manipulator. The high number of degrees of freedom allows the arm to “

snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...

” along a path or around an obstacle – hence the name “snake-arm”.

Definition

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 A confined space is a space with limited entry and egress and not suitable for human inhabitants. An example is the interior of a storage tank, occasionally entered by maintenance workers but not intended for human occupancy. Hazards in a confined ...

. 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 A linear actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer Peripheral, periphera ...

. 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

Nuclear Nuclear may refer to: Physics Relating to the nucleus of the atom: * Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear ...

** Decommissioning "Robot snake created by Bristol engineers"
Dave Harvey, BBC News Website (

bbc.co.uk BBC Online, formerly known as BBCi, is the BBC's online service. It is a large network of websites including such high-profile sites as BBC News and BBC Sport, Sport, the on-demand video and radio services branded BBC iPlayer and BBC Sounds, t ...

), 27 September 2011 ** Repair and maintenance "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"Snake-arm robots slither forward"
Jonathon Fildes, BBC News Website (

), 13 September 2006 *

Aerospace Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astrona ...

** 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 Aircraft maintenance is the performance of tasks required to ensure the continuing airworthiness of an aircraft or aircraft part, including overhaul, inspection, replacement, defect rectification, and the embodiment of modifications, compliance w ...

"Continuum Robot for in-situ repairs"
University of Nottingham MiRoR project robot * Automotive **Manufacture: Snake-arm robots allow structures to be assembled in a different way.

Security and defence

Bomb disposal Bomb disposal is an explosives engineering profession using the process by which hazardous Explosive device, explosive devices are rendered safe. ''Bomb disposal'' is an all-encompassing term to describe the separate, but interrelated functi ...

and counter terrorism *

Search and rescue Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger. The general field of search and rescue includes many specialty sub-fields, typically determined by the type of terrain the search ...

Robotic surgery

Endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

Colonoscopy Colonoscopy () or coloscopy () is the endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It can provide a visual diagnosis (''e. ...

Ingenia *

Neurosurgery Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty concerned with the surgical treatment of disorders which affect any portion of the nervous system including the brain, spinal cord and peri ...

Ingenia

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 An industrial robot is a robot system used for manufacturing. Industrial robots are automated, programmable and capable of movement on three or more axes. Typical applications of robots include welding, painting, assembly, disassembly, pick a ...

arm.
OC Robotics
a British company founded in 1997 is one of the worlds leading manufacturers of wire driven snake arm technologies.

References

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External links

Snake-arm robots are currently being researched by several major universities:
University of Toronto
A major research lab for continuum robotics.
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

Research into elephant's trunk robots
Mississippi State University
Research into designing, analyzing, and building continuum robots.
University of Nottingham
Research into continuum robots for in-situ repair applications 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). Robotic manipulators