|The control characteristics of the heliogyro are simply modeled after helicopter controls. By pitching the blades, the sail can achieve all the necessary control responses. The equation for the pitch angle of the blades with conventional helicopter controls is given as
q = q0 + a1 sin( Wt - j0 ) + b1 cos( Wt - j0 )
where q0 , a1 , and b1 vary slowly with time and j0 is an azimuth reference that is fixed in the non-rotating coordinate system and is usually chosen to coincide with the longitude axis of the helicopter. For the heliogyro, this direction should be connected to the direction of flight. The angle q0 is the collective pitch angle, and a1 and b1 are the longitudinal and lateral components of cyclic pitch.
|Drawings from MacNeal, R. H., "The Heliogyro, An Interplanetary Flying Machine", NASA Contractor's Report CR 84460, June 1967.|