Video

If weight is a consideration, getting a buck converter to convert the voltage for your raspberry pi is the way to go

@@timmarkhuff Thanks :)

This series has been on pause for a while, but I might resume soon. What kind of videos were you looking for?

@@timmarkhuff something that covers the basics of the code and how you starting building the software would be interesting. Even if it was high level and not super detailed.

I am not. Haven’t figured out how to measure airspeed yet, so I wouldn’t be able to control throttle

I was working on a proof of concept here: github.com/timmarkhuff/horizon_detector/tree/sbus, but it's not really complete. The code I wrote uses an SBUS library provided here: github.com/VermontCoder/read_sbus. I have also had some luck using this C++ SBUS library: github.com/Carbon225/raspberry-sbus. Let me know if any of that is interesting, and I might be able to make a video on it.

Yeah, there are definitely more established and straightforward ways of doing this. My project was about exploring what could be accomplished with computer vision. Who knows, maybe it could function as a backup system when IMU data is not reliable? Or maybe it was just a fun project :)

Hi Sahil. Altimeters don’t keep a plane flying level; that’s the job of a gyroscope. My system can keep the plane flying level by visually identifying the horizon. Since it doesn’t have an altimeter, it will tend to lose or gain altitude over time. I’ve tried to think of ways to visually gauge the altitude of the plane, but haven’t been able to solve that problem yet

It’s a raspberry pi camera v2 connected directly to the raspberry pi. I used cv2.VideoCapture to interface with the camera

Search for “plug and play” airplanes

Or what about putting a more powerful computer on the plane, like a Jetson. I might go in that direction at some point

I started by flying the plane manually and recording footage. I used that to develop and test the horizon detection algorithm. It became tricky when I started developing the flight controller. I had no simulation software, so most testing was in the air. I did create a simulated horizon out of poster board, which I held in front of the plane to test that it made sensible responses to changes in the horizon. Once in the air, I found that the PID controller was not well tuned (lots of oscillation). I had to do trial and error over many flights to get the PID parameters tuned reasonably.

This project has been on the back-burner for a bit, but I’m getting back into it now. I hope to have a new version available soon that controls the rudder and reads SBUS packets from the receiver. Stay tuned!

Thanks! I'll look into that

Glad it was helpful!

It's coming soon! Stay tuned

​@@timmarkhuff😢

It’s coming soon! Within a couple weeks I plan to have a version that’s ready to release

There are two cameras on the plane. A raspberry pi camera 2 is used for the computer vision operations. It also records footage onboard, and that is what you see in my videos. It doesn’t transmit footage in real-time. I also have an FPV camera with an antenna that transmits footage back to my goggles. I have never really tested the range, because I fly within a park, but sometimes at the corners of the park, the image starts to get a fuzzy, so I turn back. The airplane transmitter has RSSI, so I get warnings if signal is low, but that rarely happens in practice.

@@timmarkhuff Great stuff. Thanks!

Why no rudder control?

because it's useless unless you wish to do aerobatics (assymertic flight) or if you must have a perfect lateral control during crosswind takeoffs and landings 😅 => I think both cases are irrelevant in your case (basically mono speed aircraft. takeoffs and landings from/to whatever ) Never forget that the best way to avoid a system failure, is by deleting it lol. Go on simplicity. Use programmable/mechanical aileron differential to avoid lateral dissymetry during flight ... but maybe you have no idea of how to adjust such parameters ... ?!? If your airplane has issues with lateral stability, increase the vertical surface. An approximate formula here Va*l/b*Sw=0.035 where : Va=vertical surface (rudder and fin) l=distance from the forward 1/4 of the wing's median chord to the forward 1/4 of the vertical surface's median chord b= wingspan Sw= wing surface all figures must be in metric decimeters. I really love your project. Ask for more info if you wish :) GL

Thank you for your interest in the project! The GPIO pin numbers are passed into the TransmitterSwitch and ServoHandler objects in main.py. Please note that the version on GitHub is a slightly older version than what I use in this video. The version you see on GitHub does not use SBUS, but rather reads each output from the receiver using different GPIO pins. I plan to have the updated SBUS version of the code up on GitHub soon, but it still needs more work at this point.

@@timmarkhuff thanks! So I should wait...

@@mrmoonrc I would wait. The next version will be better and easier to install and deploy.

Currently no, I manually take off and land the plane

Why does it have to have a point?

@Raine Lauer this line of thought leads to useless waste of resources...

@@joshuajustfine Well you're just a ton of fun aren't you...

@joshuajustfine the point is to someday steal your job

It would struggle with mountains for sure. I’m interested in making a system that uses a machine learning model to find the horizon line. I’m thinking it could look at more features than just relative brightness, and therefore achieve better accuracy.

Good catch!

A steep dive would be a problem. It needs to always keep the horizon in sight. The autopilot program I wrote only allows level flight, slight turns, and slight ascents/descents so it isn’t a problem. This could be improved with a wider angle lens, but I haven’t really explored that too much.