Blimps and flight controllers

Projects General Guidance
1

Dear all,

I am looking into making an autonomous Arduino blimp. I see some attemps have already been made but some were stopped (blimpduino for example).

My questions are the following:
-Should I go for a quadcopter flight controller? Is it really worth the money? An Arduino UNO+MPU+GPS is well bellow what most flight controller cost.

-If I go for an Arduino Uno, will there be enough pins free for:
Gyroscope/accelerometer+GPS+speed controller?

-I am thinking of going hot air instead of helium. How do you suggest I integrate the heating element?

-What is your opinion on "IR lock" as a homing beacon?

Thank you!

2

Arminius_Notus:
My questions are the following:
-Should I go for a quadcopter flight controller? Is it really worth the money? An Arduino UNO+MPU+GPS is well bellow what most flight controller cost.

I'm not sure where you looked for flight controllers but HobbyKing has a nice selection with many controllers costing less than $20.

I'd think it would be much easier to program a blimp flight controller than a quadcopter or airplane flight controller.

Arminius_Notus:
-I am thinking of going hot air instead of helium.

Do you know how much bigger your envelope would need to be if you used hot air instead of helium?

I've read about a hot air blimp once. They are very rare. The one I read about could only fly in the early morning hours since this was the only time the hot air blimp produced enough lift to carry its payload.

Arminius_Notus:
How do you suggest I integrate the heating element?

What would you use as a heating element?

Arminius_Notus:
-What is your opinion on "IR lock" as a homing beacon?

I'm not sure what you mean by "IR lock". Many IR devices do not work well outside in the sunlight. The sunlight can swamp IR sensors. Fortunately GPS should work well.

3

Hi,
I think you will find the problem with a blimp is, you steer right, and some time later, depending on wind speed, altitude, temperature, the blimp might turn right the amount you need.
Ditto climbing
Ditto descending
Ditto turn left.
Ditto any action.
Will be delayed, slowed.
Hence the need for human control, you need someone to scream out, "oooooohh loook out for that (insert any life threatening obstacle)".
A more direct responding aerial contraption would be more suitable.

Tom..... :slight_smile:

4

TomGeorge:
I think you will find the problem with a blimp is, you steer right, and some time later, depending on wind speed, altitude, temperature, the blimp might turn right the amount you need.
Ditto climbing
Ditto descending
Ditto turn left.
Ditto any action.
Will be delayed, slowed.

I think you're accurately describing many blimps but not necessarily ALL blimps.

If the blimp is flying indoors, then the wind isn't really an issue. Here's a nice indoor blimp example.

The hot air blimp idea may not be as impractical as I had first thought. Here's an interesting looking RC blimp which uses hot air. Pretty cool. I was very surprised to see a hot air blimp.

Here's a related thread about an Arduino controlled blimp.

5

Thank you for you answers.

Well any flight controller I looked at were in the range of 100€+. Quadrino nano for example.

Are those you showed me as reliable? What explains the price difference? Do they have good function libraries for input and output?

Regarding hot air I have been doing some extended Excel simulations (also with use of material, heat loss etc...). You need significantly more except if you boost the heat of the hot air (which in turn causes problems with material use).

For heating elements I thought hooking up the replacement heating elements of a soldering iron but I'm not sure if that's smart and easy or just big problems waiting to happen.

Regarding IR Lock, it is the following: http://irlock.com/ . They apparently fixed the issue with interferences. Furthermore, I was thinking of using the beacon on the blimp, not the other way around ;).

I will read through the topic you suggested.

Finally about the big issue of reactivity: Blimps are also much slower than, lets say quadcopters, which allows the autonomous program much more time to detect and avoid obstacles!

6

An Arduino Uno is HEAVY. A Pro Mini or Teensy is much much lighter. Then you have to put the sensors and radios onto a circuit board, so the pre built ones look more attractive.

A soldering iron element? Is this blimp going to lift an extension cord? Also a soldering iron is designed to heat the air as little as possible. You need something that sucks in air and heats it. Like a flame. Can you run a cigarette lighter or micro torch as your heater?

7

MorganS:
You need something that sucks in air and heats it. Like a flame. Can you run a cigarette lighter or micro torch as your heater?

Some butane soldering iron/torch combos also have a hot air attachment.

I'm pretty sure I've seen these sorts of tools for less than $25 but I can't find one right now.

I did find this Dremel torch.

I personally think it would be safer to use hydrogen as your lifting gas than using hot air. It's pretty easy to generate hydrogen.

When Germany first used dirigibles to bomb England, the RAF had a hard time shooting the dirigibles down.

They had to use a combination of exploding bullets and tracers to get the hydrogen to ignite. Tracer bullets alone would pass right through the envelope of hydrogen without igniting it.

The exploding bullets would open a large hole. The tracer bullets could only ignite the hydrogen after it had a chance to mix with the surrounding air.

I certainly don't claim a hydrogen blimp is completely safe, but I think a hydrogen blimp would be safer than a hot air blimp with flammable fuels.

8

MorganS:
An Arduino Uno is HEAVY. A Pro Mini or Teensy is much much lighter. Then you have to put the sensors and radios onto a circuit board, so the pre built ones look more attractive.

A soldering iron element? Is this blimp going to lift an extension cord? Also a soldering iron is designed to heat the air as little as possible. You need something that sucks in air and heats it. Like a flame. Can you run a cigarette lighter or micro torch as your heater?

Compared to the cameras that some quadcopters lift the Uno doesn't feel that heavy. Can these flight controllers (such as the quadrino nano) be extended through shields or other external elements or are they quite "rigid"?3,7V 2000mAh battery, that would give us: 7,4 Wh

If we suppose, most of the heating will be on the ground for lift off, battery consumption won't be that high?

What do you think about using an electric arc for heating?

I understand the safety risk of hot air with flammable fuels which is why I went for idea of 100% electric.

9

Are those you showed me as reliable? What explains the price difference? Do they have good function libraries for input and output?

They are extremely reliable as they have to be in a multirotor that tends not to glide very well and many are based on Atmel chips.

They are sold in large numbers hence the low price.

What sort of input/output have you got in mind ? They already have inputs from the Rx and many of them can use a single wire PPM input. They already have outputs to drive ESCs and/or servos for control purposes.

They also have built in gyros and/or accelerometers as well as pressure sensors to allow altitude to be measured. Many will accept and use GPS data to allow Return to Home, Position Hold, Waypointing and similar functions to be used.

Telemetry data such as voltage and GPS data can be output and fed back to the Tx if required.

My current favourite is the Naze32 but more are being released all the time.

10

Arminius_Notus:
Can these flight controllers (such as the quadrino nano) be extended through shields or other external elements or are they quite "rigid"?

There are lots of flight controllers which have open source software (and I believe hardware). These open source projects should be easier to modify than a closed system.

Arminius_Notus:
If we suppose, most of the heating will be on the ground for lift off, battery consumption won't be that high?

Do you have figures on how fast you'll lose heat?

Fortunately turning energy to heat is pretty efficient. If you know how fast you'll be losing the heat, you can figure out how much battery power you'll need.

Arminius_Notus:
What do you think about using an electric arc for heating?

That sounds insanely cool (heavy on the insanely). I'd think there would be lots of ways of converting electrical energy to heat. An electric arc wasn't the first method to come to my mind. I was thinking more of an electric heat gun.

Arminius_Notus:
I understand the safety risk of hot air with flammable fuels which is why I went for idea of 100% electric.

LiPo batteries have great energy density compared with older battery technologies. Still batteries fall far short on energy density when compared with competing fuels.

I think it's safe to say the batteries on an electric vehicle are much heavier than the gasoline carried in conventional vehicles. Electric vehicles still do not have the same range as conventional vehicles.

I think it's a safe bet whenever you see a big gathering of hot air balloons, none of the balloons are heated with electric battery power (at least not while airborne).

It's likely possible to heat the air in a hot air balloon enough to keep it afloat, but the amount of time one can stay airborne will be far shorter when using electric power than if one used conventional fuels.

UKHeliBob:
They already have inputs from the Rx and many of them can use a single wire PPM input.

Some radio systems use digital data between the Tx and Rx. With Spektrum radios (and I imagine many others), it's possible to both send digital information and receive this information from the receivers. Some control boards include connectors for Spektrum satellite receivers. The data come through as asynchronous serial.

Side note (I try this in whenever I think I can get away with it): I took the small transmitter module out of a small "Blade" brand helicopter and used a microcontroller to supply the serial stream of date it expected. I was able to use the microcontroller to read the data from a Wii Nunchuck and convert this data to the protocol expected by the little transmitter module. This allowed me to fly a RC helicopter one handed. I used the joystick for roll and pitch and the accelerometer was used for yaw and throttle. It wasn't any easier to fly a helicopter this way but I sure thought it was cool (hence I mention it whenever I get a chance).

UKHeliBob:
Telemetry data such as voltage and GPS data can be output and fed back to the Tx if required.

Only certain radios use telemetry right? I think it's relatively common to use a second radio system for data. I know data can be send over the FPV's audio channel.

UKHeliBob:
My current favourite is the Naze32 but more are being released all the time.

I've heard Naze controllers are very nice. They're closed systems though aren't they? Nevermind, I decided to use use Google and what do you know, there is open source software for it! Very cool. I'll likely add one to my next HobbyKing order.

I have bunch of airplanes, helicopters, quadcopters and hexacopters, but I'd really like to add some sort of dirigible to my collection of flying things.

11

Only certain radios use telemetry right?

Yes, but it is quite common

I think it's relatively common to use a second radio system for data. I know data can be send over the FPV's audio channel.

Most RC telemetry on the 2.4 Gig band uses the same radio link as the main control signal. The Tx and Rx need to communicate both ways in order to bind in the first place so telemetry is just an extension of this. The Rx is also a Tx and vice versa.

12

UKHeliBob:
Yes, but it is quite commonMost RC telemetry on the 2.4 Gig band uses the same radio link as the main control signal. The Tx and Rx need to communicate both ways in order to bind in the first place so telemetry is just an extension of this. The Rx is also a Tx and vice versa.

Do you know of a way to hack into this exchange?

I know I can send my own data on the tx side and it's possible to receive the digital data from the receiver (though I haven't done it myself), but I'm not aware of a way to send data from the receiver to the transmitter. I imagine this would require one to burn new firmware into the receiver microcontroller. I have no idea how one would do this. Then there's the matter of getting the data out of the transmitter module. I think this would also require new firmware.

Have you used a RC system with telemetry? If so do, you have a favorite?

I've been planning to use a separate 900MHz system for data but it would sure be nice if the receiver could also transmit data back to the ground. I just don't want to have to purchase a new RC system to do so.

13

Have you used a RC system with telemetry? If so do, you have a favorite?

Yes, I use a FrSky Taranis Tx and a couple of different receivers. My main interest is in multirotors so pack voltage is of most interest to me but I have also used the barometer output of the Naze32 to monitor height.

The Taranis uses the OpenTx software which, as the name implies, is available to modify should you be interested and the receivers have a serial input into which the telemetry data is fed so it should be possible to access the data stream at the Rx end.

14

UKHeliBob:
The Taranis uses the OpenTx software which, as the name implies, is available to modify should you be interested and the receivers have a serial input into which the telemetry data is fed so it should be possible to access the data stream at the Rx end.

Interesting. Thanks for the information.