OmniTread: A serpentine robot

karvind writes "Physorg is running a story about OmniTread: a serpentine robot designed to traverse extremely difficult terrain, such as the rubble of a collapsed building. The 26-pound robot is developed at the University of Michigan U-M College of Engineering. It moves by rolling, log-style, or by lifting its head or tail, inchworm-like, and muscling itself forward. Link to videos. Check out there other robots as well."

Comments

cool

[dteichman2]

I imagine that with more development, this could lead to subways/trains without tracks. Or, perhaps "smart" cars that "know" how to handle obstacles and avoid collisions.

Spheres with tentacles are better

[GAATTC]

From a comment posted below the article: "Arthur C. Clarke had it right --- spheres with tentacles; _that_ is the ultimate in agility and mobility, for robotic design. Plus, such units can easily link together to form a much greater whole, if required --- they could perform nearly *any* engineering, construction, or transportation task."

Re:Spheres with tentacles are better

[ikkonoishi]

While spheres have the lowest surface area to volume ratio, cubes are far easier to store and link.

Memory Shape Alloys

[TimeTraveler1884]

I have always wondered why robotics engineering has not taken more approaches using memory-shape alloys. Mondo-tronics has a product called Muscle Wire that has carbon or graphite embedded in the alloy so that it heats up when an electric current is applied. This causes the Nitinol to contract as the alloy returns to its "memory" shape.

Really the only thing I have seen using this form of memory-shape alloys is just for hobbyist projects, nothing serious. Granted there are some problems to overcome, such as duty cycles and heat dissipation. But most of these could be solved, I have looked into them. On larger scale projects the cost could be prohibitive though.

The value as I see memory-shape alloys over motors, is that it is almost a solid-state actuator. There really is no moving parts that can wear, other than the alloy itself. And these memory-shape alloys have a very high force/weight ratio - thus making the bulk of most robotics not a function of locomotion.

Re:Memory Shape Alloys

[loupgarou21]

one problem is that Nitinol really doesn't contract that much, usually only 5-7% (if I'm remembering correctly) however one especially clever nitinol crawler was able to move something like 20% of it's total body length per step

What about controls?

[Statecraftsman]

That thing looks like you need more than a joystick. It'd be really great if they showed how many buttons they have on their control board. By my count the 5 segment version has 9 degrees of freedom. 1 for the front back and the other 8 for the 2 degrees of freedom for each joint.

Also, does it know which way is up and readjust or do you have to figure that out after it rolls?

Snakebots are very fragile!

[Quantum Jim]

My friend Jer Romeiko builds these kinds of robots for a living. You can download some cool videos of snakebot action at his employer's web site (CMU).

Snakebots are very fragile. Many times a section would break after a few hours demostration. Jer was working on making each section more modular and easier to build. Apparently the main goal of snakebots for many research labs are for providing demostrations (read: grantbots) and giving new grad students something to do. ;-)

Weight distribution among segments?

[ArsenneLupin]

Anybody know how to explain the photo a the 4th page of the presentation? (robot having its head and middle segment resting on top "stair", while tail is hanging "in the air").

Such position looks as if it would only be possible if "head" is substantially heavyer than "tail" (or else it would tip backwards). However, the doc states that the middle segment is the heavyest. Or does it also have the means of pumping liquid for one end segment to the other to achieve more optimal weight distribution? In any case, if such feature exist, it isn't mentioned anywhere...