[Nicholas Rehm] works during the day at the used Physics lab at Johns Hopkins, Maryland, so has significant experience with a range of UAV applications. The concern arose about exactly how the determination mars rover landing worked, which prompted [Nicholas] to hang a rock under his drone, connected by means of a winch. This verified to be interesting. however what is a lot more fascinating for us, is what occurs when you try to connect an inverted pendulum to the top of a drone in flight? (video embedded, below)
This is a classic manage theory problem, where you requirement to determine the angle of the pendulum with respect to the base, as well as close the loop by calculating the needed acceleration from the pendulum angle. normally this is demonstrated in one dimension only, however it is only a bit a lot more challenging to balance a pendulum with two degrees of freedom.
[Nicholas] very first tried to obtain the pendulum angle by just eliminating the centering springs from an analog joystick, as well as utilizing it to connect the pendulum rod to the drone body. As is rather obvious, this has a huge drawback. The pendulum angle from vertical is now the sum of the joystick angle as well as the drone angle, which with the associated measurement errors, verified to be an unusable setup. Not to be discouraged, [Nicholas] just added one more IMU board to the bottom of the pendulum, as well as kept the joystick system as a pivot only. And, as you can see from the video after the break, this undoubtedly worked.
The flight controller is [Nicholas’] own project, dRehmFlight (GitHub), which is an Arduino library meant for the Teensy 4.0, utilizing the ubiquitous MPU6050 6-DOF IMU. [Nicholas] likewise made an introduction video for the controller, which may verify instructive for those wanting to go down this road to develop their own VTOL aircraft. The code for pendulum experiment is not offered at the time of writing, maybe it will hit the GitHub in the future?
For some a lot more inverted pendulum fun, do inspect out this basic linear sled. We did cover dRehmFlight a bit while back relating to the suspended pendulum, which may likewise worth a look.