I am currently working with a team at CSU Fullerton to design and implement a UAV system. We are designing just about everything: from the airframe and related systems to the onboard image processing capabilities and more. At this stage in the design, I've run across a bit of a road block that I'm hoping you folks can help me clear.
The ordeal is this: onboard our UAV, we will have two computers running. One will be the APM (we have my personal v2.0 for testing right now, hoping to have a 2.5 or later for the final vehicle), and the other will be a small ARM based embedded computer. We are investigating options for data link with the vehicle while in air, and I have to figure out communications for both computers.
We need to have the ability to send and receive data to the APM. I need to have telemetry data, and I need to be able to adjust the flight plan mid-flight. I also need to communicate with the computer, to receive imaging data and to manage 802.11 wireless connections from out in the field (yes, I'm serious, and no, I didn't make that one up). Ideally, I'd like to get away with one radio, as I'm limited in the power I can provide to the payload systems. At first I thought I could run the mission planner software on the onboard computer and then use RPC/SSH or the like to control it and send data, but our ARM computer will be running a stripped down version of linux. I could always go the other way, and try to funnel my image data through the telemetry radio/APM, but I feel like that may not be a very good way to go about that much data transfer.
So the big questions are:
I've heard about using MAVlink instead of the usual mission planner software. Does MAVlink offer a way to receive data from the APM and command it from linux?
What's the best way to approach having an adjustable flight plan/bounding box/search area with hard restrictions?
Also, if you have any ideas on a wireless comm system with decent bandwidth at range (less than a kilometer, line of sight, and I'm shooting for 100-500 KB/s) I'm all ears.
Thanks in advance!
I guess you are new here. Go to the store, that's my idea on telemetry.
Mission planner and Ardupilot both use MAVlinlk 1.0.
Oh, ya, the most important part. You have a lot of work TODO
You have a lot unfulfilled needs with APM, most of witch are already there.
Thanks for the reply Greg. I supposed I should have asked a more focused question:
Are there linux alternatives to the mission planner software? I'd prefer to not write my own.
I've been to the store and have seen the telemetry radios they have. They would work out of the box for my application, if I had no need for interfacing with custom software on another board. I was hoping someone would have some experience with the situation I described, transmitting data from another board along with the APM telemetry and commanding the APM at the same time.
I understand I have a lot of work to do. That's why we're talking about this now, when the competition is still 9-10 months away.
Do you know where I can find data/tutorials on on-the-fly flight plan adjustment?
Which competition are you doing? AUVSI Small UAS in Pax River?
I started a team that does that comp, and we use Ardupilot.
Mission Planner is by far the most user-friendly ground control package, but if you're running Linux, you'll want Q Ground Control. All of our experience has been with Mission Planner.
For your network, take a look at Ubiquiti.They sell some nice high-power/bandwidth 802.11 equipment.
The tutorials can be found in the Ardupilot Wiki.
A word to the wise: put Ardupilot in a foam airplane and start flying right away. Also, buy more Ardupilots.
We are, in fact, planning on competing at Pax River in the summer. Definitely looking to use Ardupilot as well, since it's cheap and easy to use. Meets the accuracy requirements, and does the job fairly well. I have one I bought this summer in a Bixler, we've been flying the hell out of it (and actually flew it right into the ground last weekend, time for another trip to the hobby store!). How were you guys getting your image info down to the ground?
I'll have a look at Ubiquiti, their stuff looks really nice.
We tried making our own 802.11 setup, and it didn't work out for us. We should have used more off-the-shelf stuff. It just couldn't connect at long distances. I know for a fact that other teams use Ubiquti products, particularly the Bullet, with some success.
This past year, we actually weren't able to send image data. We just waited for the plane to land, then took the SD card out of the camera an went to work finding targets with our detection software. Even with such a simple strategy, we placed 8th in flight.
We like Ardupilot, and we'll continue to use it because of the price. You're in the same place we were a year ago. If you have any questions or need help, PM me.
Funny, I was actually out today flying one of our Bixlers. Ours came home in one piece, fortunately.