CTR - good description of EMA challenges on rotorcraft. I was essentially going to say that on most applications I’ve studied, electrical main rotor actuation is heavier and often more complex than hydraulic. I’ve seen plausible electric actuation of tail rotor type applications where demands are lower.
Originally Posted by
JohnDixson
Question, CTR: is that Karem project including higher harmonic control aspects?
Yes, Karem’s rotor is rigid both in the flap-wise and edge-wise direction and they are going to attempt to use higher harmonic blade control to largely cancel the ludicrous levels of 3P such a three bladed design will generate, especially during non-axial flow flight. At least the primary driving blade harmonic is 2P, so perhaps more predictable and at a low enough frequency to for the system to respond to. Will definitely be a challenge, though... the state of the “force generator” that is being controlled is far more complex than a simple rotating mass like many current active vibration control systems. Now you have a latency and knowledge problem with understanding the aircraft vibrations, and a lack of precise force output knowledge with the “force generator” that doesn’t exist with a rotating mass system.