Autogyros work in a constant state of autorotation and have minimal articulation; only one pivot point and no pitch control, at least not in a small autogyro. Powering the rotor in such a solution would require jet-propelled tips (which present a variety of problems in their own right) or a part time anti-torque solution.
The problem of combining the advantages of both rotary and fixed wing flight rightfully attracted lots of thought over the last eighty-plus years.
The best solution by far is the tilt-rotor, which is soon to evolve to high-speed jet-borne flight where the blades stop and fold back into the slipstream.
