I agree with the sentiments regarding the missile vs rocket thing. Adding guidance to a model rocket without authorization is fiercely illegal. You should not post this.

This isn’t a guidance system. It performs no navigation. Rather, it appears to perform closed-loop maneuvers using feedback from a 2-axis accelerometer. I can a few raised eyebrows given their choice of maneuver (transition from vertical to horizontal flight) but, it still wouldn’t call it a guidance system.

I think an interesting application of guidance would be in the *return* of model rockets. I remember launching a few 3-stage Estes rockets when I was a kid, and in every instance, we never got the top stage back. It went so high that the winds caught it and carried it off.

A GPS guided and servo-steered parachute or parasail, however, could assure that that the payload stage comes back and lands near where it was launched.

The question is whether or not this would qualify as “targeting” and whether or not, according to the accounts of some here, this would render the system a weapon.

Cool project, but how is this ‘guided’?

They have used some code and an accelerometer to get some basic attitude control.

If it could follow a predefined path, then I’d call it guided.

Oh yeah, I see whats the problem. The accelerometer doesn’t work without a proper gyro, therefore it only reacts correctly to slow changes. The quick changes just produce overreactions.

How bout we change the hate to something else, like the ARDUINO! That shit is still on the board!
You don’t have to be a ROCKET scientist to take it off.
BTW, went to Makerfaire saw a bunch of Arduinos and wanted to die. Some Makers didn’t even know the name of the chip! I almost shit.

“I’m amazed it didn’t just veer off wildly.”

This contradicts your prior sentence- it was not a complete waste of time. It did something interesting, and maybe of dubious legality (but gee whiz, give it a rest. Unless you are a federal agent charged with enforcing the rules, MYOFB.) There was some loose shit involved, but they didn’t make any bones about that, either.

It was cool, and did something unexpected; as far as I am concerned, this makes it a win, despite being a bit lopsided, with an somewhat inadequate control system. You need 6 DOF, but you can do some stuff with 3 DOF.

The whole point of projects like arduino, or wiring, is to be like a nail- a tool to hold stuff together. It is a tribute to the Arduino effort that they DON’T have to know what the micro is, Anon. It is a tool to do stuff, not a nerd badge of courage and righteousness. You don’t like them? Don’t use them.

Watching the videos, either CG is way off or this was an epic fail. The rocket took off sideways halfway through the powered phase.

@Dave Eaton: I agree with you about the Arduino, but I don’t think I’ve seen anything here to suggest that anyone is mentioning the possible illegality of a guided model rocket as a way to brow-beat the project makers. Personally, I brought it up because I’m not 100% sure about the status myself and felt that it’s, directly, related to the project. Besides myself, either this project’s creators and/or others looking to replicate a similar project might want to know that they are, or aren’t, breaking federal law. I, personally, don’t have a problem with what they’re doing, but the simple fact is that if it violates FAA/Homeland Security rules it can get you into a lot of trouble (even if it’s just a light model rocket). I just figured it made sense that we should be aware of the issue so that we know, ahead of time, that we may, or may not, be risking an things like hefty fines.

So, who’s gonna build a camera-equipped rockoon (rocket-balloon)? One team seems to be doing it already… http://fly.hiwaay.net/~bbrown/rockoon.htm

http://library.sciencemadness.org/lanl1_a/lib-www/la-pubs/00318644.pdf

put a shaped charge on it and an infra-red camera and a rocket that will burn for 30 seconds instead of 2. If you can get the cost down to a few hundred dollars this will be the AK-47 of the 21st century.

wow pat.. way to turn this in to something its not. No one here is going to get “rolled up on” because of some guys fairly inaccurate execution of a guidance system (yet commendable idea, I have planned an R/C version of this since I was little and it was going to have similar build quality probably). Just some people having fun…if you are in to extremest websites and plan to be an idiot and launch in a sensitive area then yes, I agree, you will and probably should be “rolled up on”. I don’t like that I can be wiretapped at any time but come on this isn’t politics, its some guys fulfilling a childhood fantasy.

First of all, I’d like to thank Hack A Day for posting this. K.o.D and myself read the articles on here all the time.

The term ‘guided’ was commented on, and perhaps isn’t the best word. I picked it as relative to the rocket itself, the electronics guided the rocket’s flight. Controlled would be a better term. As mentioned earlier, there is no navigation and if the definitions are not correct oh well, but I call a rocket something w/o navigation and a missile as something with navigation…. If that’s wrong, my bad.

Arduino haters: It’s modular! Once this project was done I literally took the parts out and used them on other stuff with ease, that’s all. I could have soldered up a 328 barebones, but that pretty much solidifies those components to that application…. I like being able to do multiple things quickly with fewer parts, hence Arduino is the choice.

This project was for fun and to learn, as Dave Eaton said. Getting controlled motion to work for a short period of time was the goal, and it worked. Efficiency was not a focus for this project, but will be for future projects of this type.

About the legality of this project – I have no idea. As human beings, we both made sure there were no aircraft in the area, we had water in case of fire and launched it far enough away from houses it wouldn’t create a problem. If it’s illegal and a law enforcement official comes to hunt me down, oh well. If ‘sorry’ isn’t good enough then oh well for me, lol. Doesn’t take away the fun and success of this project.

Thanks for all the comments!! Keep ‘em coming!

Good point RBRat3!

I forgot to mention the cool technical stuff… Rollerons are awesome, btw. We wanted to put a video camera onboard so we could see the amount of roll relative to the ground, but didn’t have one at the time. It doesn’t take too much fin deflection to counteract the rolling for stable flight.

Rockoons are my current favorite topic, and plans are in the making for a flight to high altitude (FAA approval WILL be granted for this, so don’t worry everyone). A friend of mine that is a NAR high power rocket club member is helping me out with this. Any ‘control’ that a rocket will use at high altitude will need a gimbaled motor as mentioned before.

As for this project, there were a lot of different things that could have been used, as mentioned but we took the idea and made it work with what we had, it’s not like it was a huge undertaking. We had a 2-axis accelerometer in our parts bin, so we used it. 3-axis gyros or even a full blown IMU would be a better option, but that stuff wasn’t in our parts bin. If we were paid to create something like this, or were getting some kind of credit for a degree then yeah it’d go from a weekend project to a couple months with fancy graphs, schematics and waiting for parts to come in. Same with the servos, yeah 2 work fine with all the hardware to connect them to the fins and all, but we had 4 so why not simplify?

I’ve said it before and I’ll say it again, we must not allow this to get into the hands of terrorists. But wouldn’t it be simpler to just use wire guidence?

@Hirudinea: I think you are underestimating those rich islamic fundamentalists. They got the money and the brains to pull this off (hey, they go to the best schools in the US and Europe!). Let’s just hope the Dept. of Homeland Security is doing its job.

On another note, I don’t see why the Arduino haters aren’t happy. Crash it and you get to kill an Arduino!!

leaving breadboard ? do he realize what stress rocket face with + unnecessary extra weight

p.s. I surprise how many mention legal bs, it sad to see so brainwashed generation, looks like if government forbid to breath you all will quietly line up on bridge and drown yourself
Its not like he shooting people or aiming it on aircrafts, if laws wast broken you all would be slaves right now

lol i like the sound it makes

I hate to be that guy, but as an idiot who thought a NO2 powered [snip] replica with a flight plan driven by boost high/coast at apogee (with a 38 mph stall while you read the GPS )in 1986 was a great idea until I got caught…. well, it was fun at the time.

The rules against powered devices with active guidance systems have been clear for a long time. But that was 15 years before 9/11. I’m not so sure folks get off on technicalities these days.

You cannot g vector stabalise a rocket, which accelerates at +2-3g, with only accelerometers. you need gyros.

also needs bigger shoot

@Dave Eaton

It doesn’t contradict the previous sentence if you understood the context, sorry I may not have made that clear. My comments about a complete waste of (my) time were in reference to bothering to watch the second video. Why on earth would I want to watch servos twitching for 1:17, seriously is that their idea of testing?
I thought if I commented it might save people the trouble of watching it themselves.

@everybody else (with a few exceptions),
stop moaning about legality and say something useful about aerodynamics, servo response times, g forces etc.
This is hack a day not don’t break the law a day

I for a gyro just pick up a wii motion plus. It uses I2C and is has been interfaced to the Arduino

As long as the rocket is not guided toward or aimed at a target and this is done on your own land, it should be ok legally. I fly high power rockets. It’s intended use or how it’s is used that would be illegal. But that’s not to say you won’t be investigated/harassed by the some government agency.

There is a sunseeker guided rocket that’s been out for a while and no issues with legality. Cool project at that level. Try it with a G motor for higher flights and more payload electronics.

@Paul I wouldn’t go up to a G with that. For one using accelerometer will not work as the flight shows.
What they really need is a gyro.
Now an interesting project would be to roll stabilize a model rocket.
You would only need one servo. It could really help with video camera shots.
@Squirrel thanks for the PID links. I have been wanting to play with augmented stability for a while now and that is just what I needed.

@lwatcdr

Good luck with the stabilisation project – it’s a very worthwhile and rewarding thing to try and do.

Just as a pointer, I noticed that you used the term ‘augmented stability’. That’s not really a term that exists in the control engineering field, so you might not have much luck if you google for it. PID loops are basically really noddy classical control, there’s absolutely tonnes of literature on the subject. ‘Modern Control Systems’ is an excellent beginner text book if you want a thorough grounding.

As a hopefully useful contribution, you’ll be aware that a fin will produce an effect that is proportional to the velocity of the fluid flow over the wing (all else being equal) so you’ll want to account for air-speed, perhaps with a pitot sensor. You then can just divide your proportional gain (Kp) by the dynamic pressure (so Kp/(0.5*density*velocity^2). The pitot sensor measures 0.5*density*velocity^2 directly so you don’t need to worry about the individual terms.

Best of luck!

@Graycode
“If you had to go to a school to figure out how to do things, then you EE people would get your hands slapped every time you used a computer to program. You did not go to a computer programmer school.”

Yes we did go to “computer programmer school”, it required for EE to take some CS classes… And because so many people did not take CS classes Apple try to turn computer into TV and big companies try to turn Internet into pay-per-view channels on TV

my idea was to use a balloon to get my device to “the edge of space” then a modified solar powered Lifter drive (ion propulsion) to get it the rest of the way.

contrary to popular belief Lifters do work somewhat in low pressure air but they do not work in a vacuum at all.

No gyros at all! Arduino calculates servo positions from the accelerometer only

that breadboard and wire mass must weigh a lot, maybe streamline the design more.
too bad you can’t set those thrusters to burst mode.
lots of good stuff here. inspired me it has!

sparkfun has a 6-axis IMU for $450:

http://www.sparkfun.com/commerce/product_info.php?products_id=8454

From their site: “The v4 provides 3 axes of acceleration data, 3 axes of gyroscopic data, and 3 axes of magnetic data.”

Looks small enough to easily fit in a model rocket, and could be just the thing we need to stay safe and on course through a flight.

Full disclosure: I am in no way related to sparkfun.com and receive no compensation of any kind for pointing out their stuff.

Yeah to all you guys that are leaving comments saying this is illegal… One dont you think the FAA has better things to do? and two this really isnt a guidence system so much as advanced stabalizer system. SO shut up and give these guys some congradulations on something that is pretty damn cool.