I'm honest: I love my drone. I mean, as a teenager, I always had remote-controlled vehicles. And of course, the most impressive RC vehicle was the gas-powered helicopter. But it was expensive and hard to fly. Now it's a breeze with a quadcopter. In addition, pictures and videos are taken.
Since I have this fascination for drones, it is only logical to take the next step and use it for some physical tasks. How about an analysis of the aviation of this particular drone, the DJI Spark? Drones, physics – what could be better?
So I took some slow-motion videos of the Spark with my phone, moving first vertically and then horizontally. Here is an example below. And then I used one of my favorite tools, the Tracker Video Analytics app, to record the drone's position in each frame. Equipped with these data, it's just a jump, a jump and a jump to derive performance data such as acceleration and thrust.
Snapshots of the drone stamped on the ball
as it moves, but I need to know the frame rate to calibrate the timescale. My phone says it records slow motion at 240 fps ̵
To re-examine this, I'm going to do a test analysis for something I already know: accelerating a ball thrown straight into the air. An object in free fall, on which only gravity acts, has a vertical acceleration of about -9.81 m / s 2 .
So if I put a dipstick in the video frame (It's the horizontal bar next to my hand, I'll know the distance scale as well as the vertical acceleration, and I can get the true frame rate.) That's how the ball looks:  Video: Rhett Allain
I have run the tracker software for this clip and adjusted the specified frame rate until the fit equation yields a vertical acceleration of -9.81 m / s. 2 played around a bit, I got a time interval of 4.28 milliseconds – about 234 frames per second Here's the trajectory with the set frame rate: