Archive for May, 2012

1988 – “Shadow” Biped Walker – David Buckley et al (British)

Shadow Biped Walker by David Buckley – 1988 

Information sourced from my friend David Buckley's own website here

Shadow Walker – Retired in 2002
A two legged human sized pneumatic powered walking robot.
Design and building started 1988.
Size – 5ft 6inches high, weight about 80lb
Operational area:- safety supporting frame 4ft * 8ft * 8ft plus host computer, a small compressor fits under the host computer's table.

Shadow Biped appearances:

1990 – the BBC TV program Tomorrow's World, live on 18th January 1990.
1990 – Robotix, The Robot Olympics Glasgow 1990 – Gold Medal for Best Robot at Robotix
1990 – The Garden Party, TV program 12th September 1990.
1996 – Robotix96, The Robot Olympics Glasgow 1996 voted 'Best Robot' by attendees.
2002 – Robodex (Japan). Invited by the organisers, voted favourite Robot by an exit poll.

Back in 1988 when the Shadow Group was new, Richard Greenhill, the founder and funder of the Group, was working on a shrugging shoulder which he thought was necessary for a robot or human to lift heavy weights such as suitcases. For David this wasn't a very fascinating aspect of robotics and he suggested that in order to attract members the group needed an appealing and challenging project such as the full sized biped robot they had often talked about. Rather than wait until everything was developed, the group could start with the legs and add the other parts as they went on. So the project to build the first Shadow Biped Walker was set in motion.

David Buckley drew up plans for the skeleton, researched medical texts for muscle placements and designed the electronics so the group could run the walker from an Acorn Archimedes computer. Richard Moyle and David Buckley built the skeleton and the electronics were built by various other members of the group. Richard Greenhill designed and built the muscles (his development of the McKibben muscle) and attached them to the legs. All the joints had potentiometers attached for position feedback and all the muscles had tension sensors. The next step was to build the pneumatic valve sets to drive the muscles.

David Buckley was working abroad and when he came back others in the group had built the two sets of air valves and switches seen in the photograph. They took up all of the body space leaving no room for any arm mechanism at all! David was very disappointed but what was built was built, maybe it was his fault for not drawing up the arms, he thought to himself. David Tricket built a pressure sensor panel with modified pressure dial gauges so everyone and the computer could read the pressure in each muscle and this was attached to the back of the robot.

Richard Walker took over writing software experimenting with all sorts of neural nets trying to get the walker to learn how to stand.

Since the robot used McKibben muscles David Buckley hoped it would be quite flexible but Richard Greenhill kept pressing for more force from the muscles and in the end it was very highly strung and could nearly stand up without any compressed air in the muscles at all!

During this time David Buckley was spending time working abroad so had little control of what went on with the robot and one time when he returned the group had decided that since some of the potentiometer fixings had come loose instead of securing them they would take off all of them and replace them with analog optical sensors.

After a lot of work especially by Richard Greenhill, in getting the sensors to work, Richard Walker discovered they were not monotonic and so more time and effort was expended on them.

The original valves were 110vac (used because Richard Greenhill bought them cheaply from Proops at around £1 each) but Richard Walker thought they didn't have enough through flow to fill the muscles fast enough for his control software to work. So they were all changed for 12v washing machine valves with enormous flow capacity. In doing so it was discovered that the reason the old valves couldn't supply the necessary air was that most of the connections in the pressure sensor panel virtually sealed off the supply and simply making them good would have been sufficient. The new valves required large fittings and only cast-iron ones were available, this set another problem because the group member who modified them didn't clean them thoroughly and they all went rusty and particles stopped the valves from working. An all night session stripping and cleaning everything was required so the robot could be shown, probably at the Robot Olympics 1996.

The new valves brought their own problems, they had rubber diaphragms and pressure bleed holes and didn't respond well to being pulsed, but Richard Walker eventually managed to tame them.

In 1998 David Buckley moved into a new house in the North of England and the walker was transferred from the Shadow labs in London with the idea that he could continue to work on it at home. However after inspecting it he realised that it would take as much work to refurbish as to build a new walker and so it was decided to retire it. The walker now hangs on the wall of the Shadow labs.
Sadly after returning from Robodex 2002 the Biped was never put back together. In 2008 the valve blocks were in a store cupboard… and the rest?…
 valve blocks.

For more information see

A good place for Biped links is – see Biped Projects

[photographs of the Shadow Biped by Richard Greenhill]  

Shadow leg

Robotic-Leg for medical research into powered prosthetics, North Carolina A & T University  2005  by David Buckley.
    The human sized Leg was made for the Shadow Robot Co. as part of a contract from North Carolina A & T University and my understanding is that it was to be used at North Carolina A & T University in a research program which would investigate myoelectric control of powered prosthetic legs. The program was to be overseen by Dr. Gary L. Lebby, a Research Professor in the Department of Electrical and Computer Engineering.

The actuators are Shadow Air muscles, a development of the McKibben artificial muscle.

Material – white acetal plate.
The leg was fitted with the control system used by the Shadow Hand 
See David Buckley's website for further photos, video clip and other details.

Shadow Hands

There are two types of hand built by Shadow.

The McKibben Shadow hand

The Electrically actuated Shadow hand.

Shadow C6M Smart Motor Hand
Electric conversion for Shadow Pneumatic Dextrous Hand.  Summer 2008  by David Buckley.
      For The Shadow Robot Company.
Mechanical design of the forearm and wrist for the conversion of the Shadow Pneumatic Dextrous Hand to use electric motors together with force sensing feedback to achieve active compliance. Debugging and reworking of existing motor control boards and force sensors for use with the new arm. The project also required learning and becoming skilled in ProDesktop, the CAD program Shadow use.

See David Buckley's website for further photos, video clip and other details.

An earlier Shadow KcKibben-actuated arm

See other Pneumatic, Fluidic, and Inflatable robots here.

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1999 – Slim Slime Snake Robot – Shigeo Hirose and Takeshi Aoki (Japanese)

Slim Slime Robot

The Slim Slime robot is a robot made up of linearly connecting multiple modules that pneumatically bend and elongate. Inside a module (below), three metal bellows are arranged in parallel at regular intervals with an identical circumference.
Both ends of each bellows are fixed with two disks, and the disks are connected to each other by expanding springs. These bellows elongate when compressed air is supplied, and they shrink when the air is drained out. Each bellow has two solenoid valves embedded, used for the intake and expulsion of the compressed air. The module bends and elongates by controlling the compressed air that is supplied to the three bellows. The module is 128 mm in diameter, from 114 to 178 mm in length, 1.7 kg in weight, and has a maximumbending angle of 30.

The Slim Slime robot is composed of six connected modules, from 730 to 1,120 mm in length and 12 kg in weight. The Slim Slime robot has realized a wide variety of movement styles by bending and elongating. This robot has also succeeded in performing locomotion in an inclined pipe (bottom).

Built by Takeshi Aoki and Shigeo Hirose at the Hirose Fukushima Lab.

There is a later model, SSR-II which used a "Bridled Bellows".

See other Pneumatic, Fluidic, and Inflatable robots here.

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1995 – KSI Tentacle Manipulator – Immega and Antonelli (American)

Kinetic Sciences Inc. (1995) developed a tentacular robot, powered by a hybrid system of pneumatic bellows and electric motors. It can extend, contract and bend in 6 dof by using tendons threaded through cable guides.

Tentacle-like manipulators with adjustable tension lines by Guy Immega

Patent number: 5317952
Filing date: Dec 14, 1992
Issue date: Jun 7, 1994

A tentacle-like manipulator has a resiliently longitudinally extensible, laterally bendable elongate member, e.g. an inflatable bellows or a helical compression spring-like member, with an end effector mounting on one end thereof. Tendon-like tension members extend along said elongate member and are spaced apart from one another around said elongate member, one end of each of said tension members being to said elongate member at said one end thereof. Guides spaced apart along and secured to said elongate member and slidably engage said tension members for guiding said tension members relative to said elongate member. Further tension members extend along only a portion of the length of the elongate member and are secured to the elongate member at a location intermediate the ends of the elongate member. Winches are used to wind and unwind the tension members to correspondingly control the length and the bending of the elongate member.

See full patent details here.

Kinetic Sciences Inc. – Immega and Antonelli

See my related Immega Pneumatic Bellows article here.

See other Pneumatic, Fluidic, and Inflatable robots here.

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1990 – Inflatable Robot Arm – Yoram Koren (Israeli/American)

A world’s-first robot that he built had inflatable arm linkages for deployment in hostile and confined spaces. The inflatable robot is a low-volume and low-weight alternative to rigid arms. The inflatable robot arms can achieve the required load-bearing capacity and rigidity through the appropriate selection of size and pressure. The links of the robot are made of thin film material and are inflatable by air or other gas. The robot can achieve the required load-bearing capacity and rigidity through the appropriate selection of materials, size and pressure. This robot might be useful for surveillance and resource operations, or in areas difficult to access in buildings.

An inflatable structure, particularly adapted for use in outer space, employs one or more inflatable links which are connected at a base of the structure. A distal end of an outer most link is provided with a gripper assembly which can be remote controlled, and suitable encoders are included to indicate the angular position of each of the links. The motors for driving the at least one link is situated at the base to thereby reduce the mass of the at least one link and correspondingly reduce moments of inertia during operation.

Inflatable structure Yoram Koren and Yechiel Weinstein    
Patent number: 5065640
Filing date: Jul 9, 1990
Issue date: Nov 19, 1991

See here for full patent details.

Although Yoran is Israeli, he invented this arm whilst working at the University of Michigan.

See other Pneumatic, Fluidic, and Inflatable robots here.

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1994 – Inflatable Robot – Patricia Dombiak (Ben-Horin) et al (Israeli)

A Six Degrees-of-Freedom parallel inflatable robot.
Patricia Dombiak (Ben-Horin), Moshe Shoham and Gershon Grossman.

Little is known about this robot. It was built as part of her Masters Thesis. P. Ben-Horin, M.Sc., "A Six Degrees-of-Freedom Parallel Robot with Three Planarly Actuated Links", 1994. Technion – Israel Institute of Technology, Dept. of Mechanical engineering, The Kahn Medical Robotics Laboratory for Research and Instruction.

See other Pneumatic, Fluidic, and Inflatable robots here.

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