The sky crane system used on the Perseverance and Curiosity Mars rovers is a challenging control system problem that peaked [Nicholas Rehm]’s curiosity. Constrained to Earth, he decided to investigate the problem using a drone and a rock.
The setup and the tests are simple, but clearly illustrate the problem faced by NASA engineers. [Nicholas] attached a winch mechanism to the bottom of a racing-type quadcopter, and tied a mass to the end of the winch line. At first, he built a foam model of the rover, but it proved to be unstable in the wake of the quadcopter’s propellers, so