GYROSCOPE stabilised rocket - hmmmm

[pinter75]

I have been thinking about stabilising a rocket using RC GYROs and servos. I would have a go at building a prototype, but I will need 2 Heading Hold piezo gyros and 2 digital high speed servos - all of which are expensive.

Here are the designs so far.

A 3d see through of the control tech and movable surfaces. I have used a ejection blow through tube to protect the electronics.

Sort of what it could look like.

I have also made a small animation video showing how the servos move the fin surfaces.

You can see that here (needs quick time and MSIE or Netscape 7).

Steve C.

 

[Prowler901]

That is totally AWESOME!

You would be my hero if you can pull it off

One question. Can the servos you are intending to use actuate fast enough to keep up with the rocket?

Regards,
Todd

 

[rstaff3]

This is a cool concept and I look forward to hearing your progress. The only semi-successful electronically steered (we'll stay away from the word 'guided' since it has bad implications) rocket was a sun-seeker. Instead of reacting to sun sensors yours will be driven off the gyros.

Another issue is weight, maybe the gyros and associated electronics should be in the nose? Also, you think that having the gyros further away from the CG would be a benefit?

 

[shockwaveriderz]

pinter75: build it and they will come, so will I...

My only suggestion is to move some of the weight of the electronics more forward if possible......It going to take at least a D-E engine to get this off the ground to a respectable altitude...


but then on the other hand, it also depends on what you plan on placing n the top.....may I suggest soem kinf ocamera or video camera?


excellent design, good luck....

 

[vjp]

To prove that it's the gyro-operated fins, and not merely static
stability, which is stabilizing the rocket, it would be necessary to
prove that the rocket itself, without active fins, was unstable.

i.e., you should make the rocket dynamically 'neutral' so that
without active stabilization, it would not fly straight and true.

 

[rstaff3]

Some quick thoughts:

How about testing in windy conditions? Have a fixed fin position with the electronics off and observe the amount of weathercocking. The engage the electonics and see if it flies straight up?

How about having the fins canted at the start to give an inital turn and see if the system corrects itself?

If the system isn't designed right, it will make the normally stable rocket go nuts. Maybe a nominal flight with the system engaged is itself an indicator?

Maybe you need a flight computer to log the system state?

 

[matt_taylor]

i have the HPR magazine with that article in it, i think there is also another article too, i can dig it up and scan it if anyone wants


matt

 

[powderburner]

pinter75,

You indicated that this system might be expensive. Can you ball-park that statement a bit? Are we talking $100 per rocket or $1000 per rocket? (or more?) Do we expect that this thing will eat batteries, maybe require a fresh reload per flight?

A larger issue to be addressed would be what is the failure mode of a rocket equipped with such a system? If we are standing around, 50 feet or 50 meters away, and this thing decides to quit before it reaches the end of the rail, there is a 'safety-of-flight' sort of question (actually, a 'safety of bystanders' issue) that comes to mind. If we require the rocket to be inherently stable so as to still have a safe flight after a failure, this has some serious design impacts. Not only do we have to design a conventionally stable rocket to begin with, but now we have to add a fail-safe mechanism to your gyro chain; the added device must ensure that the fins return to true streamwise from whatever position they had previously been commanded.

I think you will have to consider the failure mode problem, else the outfits like NAR and Tripoli will be reluctant to put their insurance policies and flying privileges at risk.

 

[pinter75]

I have decied to can this idea, as I only fly LPR and they seem to go straight anyway

I just had an idea when I saw that gyros for rc helicopters/planes were quite cheap on ebay. I could have got 2 for about £21, but they were mechanical and a bit big. The piezo heading hold gyros are about £30 a piece plus the servos will have to be high speed digital ones. I also think a circuit will have to be built to pulse the gyros to replace fitting a reciever which would be a). dangerous b). Illegal?

Steve C.

 

[Fore Check]

If nothing else, your command of 3D rendering is quite impressive and worth posting more pics of your concepts (as proven here and in the "Got Boost?" thread)

 

[lamart72]

John Pursley has done this on one of his Vanguard rockets.
The website is www.accur8.com. Look under Scale Projects and then 1/10 Scale Vanguard. There is some good info there.

 

[rstaff3]

Hey, I enjoyed this thread even if it is just hypothetical. Keep throwing your ideas out here. And I too think your 3-D views are nice!

 

[pinter75]

Remove all fins, build a movable motor holder and use the servos to move that - I think that is called a Gimballed motor?

This guidance stuf is fascinating

 

[powderburner]

Originally posted by Fore Check
If nothing else, your command of 3D rendering is quite impressive

I agree, pinter75, those graphics look great! What software did you use to create these?

 

[pinter75]

MS Paint

No really I used this: Discreet 3D Studio MAX 5. https://www.discreet.com/products/3dsmax/

 

[powderburner]

pinter,
I used your link to go check out this software.
It's a bit too pricey for me at $3105 (that last $5 put it just out of my range). Is this software something you have at work (and get to play with on the side) or is this really something you bought to take home? (if so, I am greatly impressed)

 

[Stymye]

Pinter,

great project idea!

the biggest hurdle to gyro stabilised or gimbaled
set ups would be the reaction time

the rocket is traveling very fast (obviously) and can change it's course in the blink of an eye...

I know that some rocketeers have been sucessfull (to a certain degree) but don't expect a fully controlled arrow straight flight without some serious tinkering...by all means, go for it!