What are good options for modifying drones?

Question

I'm apart of a group at my University where we would like to build a drone/UAV and constantly add and modify parts on it.

We were thinking of using an Arduino or raspberry pi, but we really don't want to mess with PID loops. However, with these microcontrollers we can easily add multiple sensors and a GPS. We can build the frame, do soldering, and everything else, but we would like some type of pre-made PID loop or flight controller so we don't need to worry about the drone falling from the sky.

Would anybody have any recommendations for us? Maybe flight controllers that we can add anything else on top of, and then change the code. Or a pre-built drone where we can modify its code and add sensors.

Any help is extremely appreciated. Thanks!

Answer 1

Seems like you're looking for a basic flight controller, for example, the PIXHAWK. It comes with onboard IMUs and GPS support, while being able to run two main types of firmware: PX4 and ArduCopter. Firmware like this contains PID loops, flight control algorithms, flight mode switching support etc. while being open source and easily customizable if you have some C++ experience. Also, PIXHAWK supports the widely used MAVLINK protocol for sending and receiving messages, which allows you to send offboard position, velocity commands etc. or write your own commands adhering to the MAVLINK protocol.

On the other hand, boards like this are only good for low level control: so for anything vision based or for other kinds of sensing, you'd need a companion computer. If you have a companion computer like the RPi, you can use MAVROS to interface with the PIXHAWK(https://github.com/mavlink/mavros).

If you want to make this whole process easier and get something off the shelf, there are some platforms like the 'ErleCopter': it already comes with the ArduPilot flight stack and a RPi computer installed on a multirotor platform. Or if you're still interested in the custom platform route, there are also certain boards like the NavIO: (RPi + PIXHAWK) combo which you can install on your own custom platform.

Hope this helps.

Answer 2

I would recommend looking at acquiring an Intel Aero RTF (Ready-to-Fly) drone, if your group can afford it.

It ships with flight controller, etc. already set up, and the Realsense camera includes IR and depth.

You will have to flash the firmware before you can really do much, but the git repo wiki holds your hand through this pretty reliably. and Intel's evangalist team is very responsive and dedicated. The default examples are pretty robust and informative and you can go from unboxing to basic autonomous flight and computer vision / machine learning just by walking through the wiki. Thanks to the Intel ecosystem, it supports some really neat advanced capabilities including the Movidius VPU, NVIDIA TX2, etc.

The most annoying thing we ran into was power supply; it ships "batteries not included" and also with no AC power adapter. Since it also uses a hard-to-find xt60 type connection, you'll have to order an XT60 to wall solution from Amazon separately.

HTH.