They are definitely winches. We are not using a rope drive with pulley but a double winch drive on both ends of a single cable. A rope belt does not give enough reel-in / reel-out distance to be power productive. The prototype is currently using a pulley and belt since we are only using it for aerodynamic and control studies at a fixed distance and not for power production.
Here’s the architecture from the patent to help you understand the system design for power production.
There are two simple equations which govern the reel-out speed (r_dot) and the cylinder rotation (omega) based upon the reeling speeds of winch line 1 and 2 (V1 & V2) and the cylinder radius (r_cylinder).
(V1+V2)/2 = r_dot
(V1-V2)/r_cylinder = omega
So yes, reeling and rotation are possible at the same time depending on speed and direction of the pair of winches. And I can confirm that the energy required to rotate the cylinder is significantly less than the energy produced during the generation phase (as hinted at in the poster).
