Like A Cat, New Robot Lands On Its Feet

eckenheimer writes "Students at the Physics Department at Drury University have developed a robot that uses motions and contortions of its body to orient itself in zero gravity. According to the project site, 'If you've ever seen a cat land on its feet after falling while upside down then you've seen the idea behind our project.' The effort is a proposal for the NASA Reduced Gravity Student Flight Opportunities Program."

Cats landing on their feet

[thedogcow]

This was explained to me in my physics for engineers class...

Cats reposition themselves to land on their feet because they can sense the change in velocity (dv/dt = acceleration). My professor stated this only works for small height values (less than 20 ft), otherwise, the acceleration due to gravity might result in an unpleasant aftermath.

Re:Cats landing on their feet

[Kenja]

I recall reading a bit about how after the 10th floor, cats cat spread thir legs and "glide" to slow down enough to survive. Statistics show that there are more feline fatalities between floors 3-10 then there are after 10.

Re:Where's the beef?

[enforcer999]

Here [drury.edu] you go. It is not a very "pretty" robot but it could have its uses.

Re:Have to wonder how they did their research...

[jfengel]

That research was already done [physlink.com]. Complete with pictures of dropped cats. These guys are just taking advantage of the previous research.

Re:Cats landing on their feet

[Anonymous Coward]

Cats don't just jump from top floors. They also can fall from intermediate floors while trying to grab birds and other critters who wander about on window ledges and push screens out of windows.

I had a cat who almost did this once. He was head-butting the screen so much when he saw me coming I thought he was going to either break the screen or force it out of the tracks.

RGSFOP

[ghack]

As an individual who has participated in the RGSFOP program, I have seen a number of novel experiments, but this particular experiment is a retread that has been done many, many times. Last March, for example, Washington-St. Louis did a very interesting experiment involving zero-gravity orientation of a space vehicle. The typical RGSFOP experiment fails, however, although my University did experience a success this year.

A list of active RGSFOP teams [nasa.gov]

Re:Air pressure

[Anonymous Coward]

The GYRE robot [washington.edu], which flew last year, did just that. And hopefully will do so again.

Re:Story Musgrave

[roman_mir]

Sit calmly in a swivel chair, slowly extend your legs, then extend your arms to one side, say to the left, move your arms from that position to the other side of your legs at the same time pull your arms close to your body, at the same time push your pelvis in opposite direction to your arms.
There you have it, net angular momentum is 0 but you are still rotating.

Absolute crock of shit

[SuperBanana]

Cats falling from very high heights (i.e. skyscrapers) tend to survive the fall better than those falling from lower elevations.

Um- no. Every bone in their body breaks and their internal organs are crushed, just like a human. The "paper" you cite is an absolute crock of shit- they have TWO datapoints, and among other things, the data-fit is so poor it implies 100% survival rates above 8 stories for cats! BullSHIT! Nevermind that they consider "skyscraper" to be "under 7 stories", when most people consider a skyscraper to be at least 50 or much more.

Cats DO survive a two or three story fall(which is nowhere NEAR their terminal velocity) better than they will survive a one story fall, purely because they have plenty of time to orient themselves and extend their legs for full cushioning of the fall. If they don't have time to orient themselves, they often don't get their body fully aligned and it's a roll of the dice between bone strength and impact velocity.

Already in use

[cjameshuff]

As far as I can tell, this is basically an overly complex version of a momentum wheel...basically, a massive, low-speed flywheel. Spin it one way, the surrounding structure spins the opposite direction...stop the momentum wheel, and the entire structure stops spinning. That is, angular momentum for the entire structure is conserved.

The Hubble telescope uses momentum wheels for very precise aiming without requiring propellant and complex, failure-prone, and mirror-dirtying thrusters. These people are trying too hard...the basic idea is just a massive wheel attached to an electric motor.