Need ideas for my blimp project

[dR.eXntriK]

So a couple of guys in my college are arranging an event in the campus and we were thinking of a way advertising it around the campus. One of my friend came up with the idea of making a blimp with the details of the event on it and let it fly around the campus.
We are already started of with designs and calculations and I can say we're pretty much set with that. However, there are still a few things to consider
1.) The blimp has to be flown all around the campus, so we thought of making it an RC blimp. But that would require some one to keep going behind it all day long. So I thought why not automate its movement.
"That is a fantastic idea" they all said (including my professors) and I also told them I would take care of all the electronics. However, here is the actual problem. I AM A ELECTRONICS N00B.
I've never built anything, let alone something this complex, and I don't know how and where to start. I'd really appreciate it if you humble guys could help me out with this electronics stuff. (Like circuit design, components to use, suggestions, telling me how dumb I was to take up something I don't know s**t about/scolding me)
After a little bit of a thought process, I came with some ideas for it.
1.) Make a central station which sends out signals(Lets say bluetooth or wi-fi) of particular freq upto some distance. Make a wireless connection between the blimp and the central station such that the blimp keeps flying round and round within the radius of the signal emitted by the central station.
2.) Make a charging dock so that after a couple of rounds, the blimp comes to the charging dock for a battery recharge.

I know this stuff is complex, but I will have a lot of hands helping me on this. But before i can get some help I need to know how and where to start this stuff.
From the deepest trenches of my heart, I request you kind people to PLEASE help me make a reputation. PLEASE!

 

[Gryd3]

I won't scold you, or make fun of you. That's not my job nor my place.

I am unsure what your deadline or budget is though.
Initially, my thoughts are requiring a GPS, and camera.
Locating the charging dock without vision will be very difficult, so will object avoidance.
Also, using a wireless signal as a sort of geo-fence may be difficult as well because the signal will not be uniform and may be obstructed or interfered with depending on where you are on campus.

More details are needed:
-Budget
-Size limitations
-Designated Fly Zone
-Any experience programming?

 

[dR.eXntriK]

hey Gryd3,
Thanks for the reply and for not scolding me
Anyway, I don't think a camera is within budget. So lets just skip the charging dock for now. We'll manually charge it later.
Here are the details you asked for:
1.) Budget- around $100 ~ $150 max.
2.) Size- around 8ft ~ 10ft in length with a capacity to carry about 15 kilograms of weight
3.) Designated fly zone: Open air, within campus with no obstruction. However it will be subjected to fairly strong winds.
4.) Yes, I have some programming experience in Java and C++. Now learning python, ruby and HTML 5.

 

[Gryd3]

Well.. I hate to tell you that a complete automatic solution may be out of the budget.
You need to have a sensor or combination of sensors it can use to orientate itself and determine its approximate location. This could be done using 3 or more wireless base stations allowing it to triangulate it's rough position, but this is beyond me.
You need some way to determine location, but the budget does not seem like it will allow GPS, or a camera. The most you could do would probably be a gryoscope to make sure it keeps it's same heading, but the wind could be a severe problem.
You need range detection to keep proper altitude and prevent collisions. Ultrasonic Ping sensors can be used.

You may need to experiment with some unique solutions that may involve IR LED markers along a path you want it to follow, some kind of tether to the ground, or a directional antenna if you wanted to use RF to have it locate a rough 'home'.

 

[davenn]

This is really a major electronics project and definitely not for a noob. You would need the help of some very skilled electronics guys to "get this project off the ground" (pun intended)

cheers
Dave

 

[Gryd3]

This is really a major electronics project and definitely not for a noob. You would need the help of some very skilled electronics guys to "get this project off the ground" (pun intended)

cheers
Dave

Depending on desired hardware
He's got programming experience, so slapping a RaspberryPi on a blimp with a GPS module, camera, and OpenCV would not be out of the question. The budget makes it so though...
Controlling the IOs from the PI would be as easy as reading or writing a Linux file, and it could be directly connected to RC servos or brushless motor controllers.

Would be more of a software project with a little hardware mixed in.

 

[KrisBlueNZ]

Smartphones have GPS and a magnetic compass built in, and if it's a temporary requirement, you could borrow one, or get an old cast-off or spare smartphone. The blimp will be self-orienting vertically, so a compass might be enough to determine orientation, unless there are strong local magnetic fields. You could hack something to control two motors for propulsion using the headphone output. Do you know anyone with Android or iOS programming experience?

 

[dR.eXntriK]

Smartphones have GPS and a magnetic compass built in, and if it's a temporary requirement, you could borrow one, or get an old cast-off or spare smartphone. The blimp will be self-orienting vertically, so a compass might be enough to determine orientation, unless there are strong local magnetic fields. You could hack something to control two motors for propulsion using the headphone output. Do you know anyone with Android or iOS programming experience?

Thats a fantastic idea Kris. I am infact learning android programming and I might just be able to make an app to use the compass and maybe the camera. But there are motors which need to be controlled. How can i do that?

 

[Gryd3]

Thats a fantastic idea Kris. I am infact learning android programming and I might just be able to make an app to use the compass and maybe the camera. But there are motors which need to be controlled. How can i do that?

You could hack something to control two motors for propulsion using the headphone output.

This would require a custom circuit, but would be pretty cheap to build. The catch here though is that I understand the idea, but am unsure exactly how the circuit would be implemented. You would be controlling direction and speed with audio signals.

 

[dR.eXntriK]

This would require a custom circuit, but would be pretty cheap to build. The catch here though is that I understand the idea, but am unsure exactly how the circuit would be implemented. You would be controlling direction and speed with audio signals.

Ya. I kinda figured that out. I can control the two motors by sending a sound signal (either Left or Right) via a headphone and connecting the other end (ear piece) of the cord to another circuit which identifies L or R and controls that motor.
I can make the blimp turn toward left by locking the left motor & running the right motor at full speed and vice versa for the other direction. So can you kind fellas please tell me if this logic is correct and if it is correct, then what kind of circuit should i use. Can someone please give me a list of components and rough design please?
Thanks!

 

[BobK]

How large is this thing? Have you checked local regulations on flying drones? This might not be legal.

Bob

 

[Gryd3]

How large is this thing?

2.) Size- around 8ft ~ 10ft in length with a capacity to carry about 15 kilograms of weight

I didn't think drones have been reclassified yet.. Who would you need to speak to?

 

[BobK]

Well, in the U.S. it is not real clear right now.

If used for non-commercial purposes, they are legal in uncontrolled airspace. Everything above 1200 feet is controlled airspace in the U.S. and near airports and military facilities it can extend to the ground. There is also a 700 ft limit in some places.

In other countries, who knows?

Bob

 

[KrisBlueNZ]

Well, with two signals, you have two lots of frequency and two lots of amplitude to control, and both of those can be detected fairly easily and converted into voltages, so you would have four linear signals you could control independently. How many do you need? Two motor speed controls? Some kind of rudder position? Anything else?

 

[dR.eXntriK]

Well, in the U.S. it is not real clear right now.

If used for non-commercial purposes, they are legal in uncontrolled airspace. Everything above 1200 feet is controlled airspace in the U.S. and near airports and military facilities it can extend to the ground. There is also a 700 ft limit in some places.

In other countries, who knows?

Bob

Well I don't think there are any restrictions here as the blimp is just used for advertising and the max height it would reach is about 50ft off the ground and since its a just within the airspace of the college ,there wont be any problem either.
The biggest problem right now would be designing and building the entire thing

 

[dR.eXntriK]

Well, with two signals, you have two lots of frequency and two lots of amplitude to control, and both of those can be detected fairly easily and converted into voltages, so you would have four linear signals you could control independently. How many do you need? Two motor speed controls? Some kind of rudder position? Anything else?

I think we will be using only two motors for direction control and no rudders.
Just two motors on either side of the blimp. If its insufficient then we might add another set. But no rudder controls, it make things more difficult

 

[Gryd3]

Good call on avoiding the rudder. If you set up the Left channel frequency to the left motor and Right channel frequency to the right motor. If you need to add extra, just hook em up in parallel.
There are specific ICs like this one > http://www.ti.com/lit/ds/symlink/lm2907-n.pdf < that will take a frequency and convert it directly to voltage.
You can easily drive motors with this, and your program can control the motors simply by playing a higher frequency to drive faster

 

[dR.eXntriK]

Good call on avoiding the rudder. If you set up the Left channel frequency to the left motor and Right channel frequency to the right motor. If you need to add extra, just hook em up in parallel.
There are specific ICs like this one > http://www.ti.com/lit/ds/symlink/lm2907-n.pdf < that will take a frequency and convert it directly to voltage.
You can easily drive motors with this, and your program can control the motors simply by playing a higher frequency to drive faster

Wonderful! Thanks Gryd3.
Now tell me if these are correct or any changes required.
1. We make a blimp and mount motors on it, connected to suitable circuits. (I am gonna need your expertise on the circuits part though!)
2. I use an android phone as the brains of the "AIRCRAFT"
3. I build an app which uses GPS to find its position and the compass to turn the blimp in the suitable direction. (Need some, <scratch that> A LOT of advice on this part. How, what, when etc etc stuff)
4. I hook up everything to the blimp
5. Fill the blimp with Helium
6. Pray to GOD that it works and keeps working through the day!

 

[BobK]

the max height it would reach is about 50ft off the ground

Which brings up an interesting point, how are you going to control the altitude?

Bob

 

[Gryd3]

Which brings up an interesting point, how are you going to control the altitude?

Bob

I guess those motors will have to tilt to push the craft up/down
I wonder how accurate the phones will be with the GPS determining altitude...