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Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Stopping a frame from falling using gyros (but keeping agility/manoeuverability

(OP)
Hello,

I am trying to figure out if gyros could solve my problem i would like to design a frame that will not topple over (rough height 1 metre) it needs to stay upright i.e cant be pushed over (mainly left or right) but can still be moved forward or backwards easily .. if gyros could be a solution how could i figure out what force i could exert left or right without the frame toppling .

Thankyou in advanced with any insite or help

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Time to whip out the ol' dynamics book and brush up on those vectors and all.
One observation: When you push on it, it doesn't stay stationary, it rotates slowly. So the question there is "how slowly do you need it to move". It's a dynamics problem, not a statics problem.
Second observation: As I recall, a single gyroscope left on it's own will rotate slowly in other directions, not necessarily something you want a frame to do.

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Hello,
gyros is greek winky smile and means circle, so a gyroscopic effect (self stabilization) is based on the rotation of a material body where the COG is located suitably. However, this needs a drive to impart the rotation.

From the spin of your post however i'd rather conclude you don't want to push a rotating object, but to prevent the movement of that frame into certain directions whereas being able to move it in others. So, a guide track or rail guiding might be a step towards your intent.

Do you have any mechanical engineering handbooks / some qualified mechanical engineer / technical college o.e. close at hand?
And a sketch would be a very nice first step towards a better understanding of your idea..
Regards

Roland Heilmann
Lpz FRG

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

(OP)
Hello

Roland Heilmann,

That is completley correct about the frame i want to be able to design it to not fall over but still maintain its forward movement ( imagine an elderly person and a zimmerframe) whilst the zimmer is fantastic going forward and backwards .. the problem lies with it toppling sideways i want to negate that problem.
So my thinking would be either a gyro in each leg rotating counter to each other using a motor and a simple gimball device to stop left and right deviation. Or a single larger gyro in the cog the only problem is i need it to be as light weight as possible.
Hopefully this clears up my intentions. Currently working on a sketch

Thanks :)

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Deano12,

Mechanically, a gyro drastically increases the moment of inertia of your assembly. The gyro does not stop rotation, it just makes it very much slower. Such a gyro must be very large in relation to your assembly. Tiny gyros are part of an instrument that that tells a servo-system what angle your assembly is sitting at.

--
JHG

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

(OP)
Hum so what you are saying proportionally to the frame it wouldnt be possible without a rather large/heavy gyro ..
I was under the impression with gyros if it went to a certain point then a motor would precess the gyro back to a fixed point in space (want for a better word) which would stop or limit a toppling effect ?

Thanks
Jhg

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Deano12,

Look at the picture attached to RolMec's post. That is what those gyros look like that you buy from science stores. You can spin a smaller gyro faster, but it still will be a substantial piece of hardware. You need to distinguish between a dumb disc that rotates and creates inertia, and a servo-system that reads some orientation detector and that sends signals to a servo-drive.

--
JHG

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

(OP)
Ok yes I see what you mean much more complex than originally anticipated
Thank you for your help !

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Do the gyros have to be mounted on the frame? Would sensors/servos/feedback links to an independently mounted gyro work? (Kinda like a robot driving a Segue?)

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

(OP)
The frame needs to be mobile and stay upright .. i.e not fall left or right.

The gyro would have to be on the frame as the frame needs to be able to go anywhere (shops restauraunts roads ect)

There is a new bike out that uses a gyro in its front wheel which (suposedly makes it impossible to push over .. would two smaller versions of this attached to the bottom of a frame in the form of a wheel work maybe ?

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

If the frame has an overhead tie or bar you might be better served using one of the huge number of electronic gyro sensors and a center of gravity weight that can be servo shifted from one side to the other. A servo system could easily compensate your described system. This system would not tend to overturn the frame if it failed or freaked, whereas if a gyro's bearings seized - no one would want to be near the frame as it vaulted into the sky or started counter-rotating.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Seems like you're looking for something like this: https://www.youtube.com/watch?v=ANUWBNLoN28

Note that it's NOT just a gyro; there's actually a stabilization controller that goes with that, which is why the system can compensate for the drift of the CMG

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Why not tilt switches?

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

I heard today on a local radio station during my morning commute of 2 hours that someone has developed a motorcycle that will stand on its own without a rider or kickstand using exactly that - a gyro mechanism. No Kidding!

Mike McCann, PE, SE (WA)


RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

(OP)
All amazing ideas thankyou guys for your help !!
Yes IRstuff literally what i was thinking !
I will look into the servo systems ITs smoked .. as also sounds doable ..

Cheers guys all really helping

:)

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Probably. I just heard about it on the radio. Never saw the picture... until now. Thanks.

Mike McCann, PE, SE (WA)


RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

Deano12. As already mentioned above, it isn't "impossible" to topple a gyro, nor does it return to it's former orientation if disturbed. All it does is apply a torque about the third axis if a "toppling" moment is applied about an axis at 90 deg to the axis of rotation. So if you try to roll a vehicle with a vertically oriented gyro, it will try to pitch and vice-versa. Get yourself a bicycle wheel, spin it up the try to re-orient the axle. Or you could look for one of the many You Tube videos on the subject.

A self stabilising vehicle like the BMW in the link would have to have an active stabilising system - perhaps a vertical gyro with the roll orientation of its axis positioned by a motor.

je suis charlie

RE: Stopping a frame from falling using gyros (but keeping agility/manoeuverability

If the orientation is ostensibly fixed, i.e., "this side "up", then accelerometers might be a nice complement to a 3-axis or 2-axis gyro subsystem. Gyros are excellent for detecting low angular rates, but the integrated angular position will drift due to integration errors, while accelerometers can measure the absolute angle position without drift.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers

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