Flight Physics Of The Quadcopter

[HiDesertHal]

I have an RC helicopter, which has a servo-activated mechanism that varies the collective pitch of the main rotor (as with the real machine), and along with the tail rotor, allows complete maneuverability in flight.

My question about the Quadcopter's flight physics is how does it maneuver in Yaw, Pitch, and Roll, and in forward flight speed?
Is it done by differential speeds among the four rotors? Since all four blades are fixed in pitch, then differential rotor speeds are all I can think of for its abilty to maneuver. Am I right?

Please elaborate if necessary.....
Thanks, my Fellow Engineers!

HiDesertHal

 

[LoneRCRanger]

In one simple way, yes, the quad varies the rotor speeds for maneuvering. The details would take a book to explain.

 

[RENOV8R]

You are correct, the pitch and roll are only controlled by motor speed. Simply put, if the front 2 motors are decreased and the rear 2 are increased, you have forward flight. This is why when you see a quad moving at a high rate of speed, the forward angle can be up to 45 degrees. Yaw is a little more complicated. There are thousands of sites that explain the theory in depth, this one is pretty good without getting super complicated
http://www.thedronesmag.com/the-physics-of-multirotor-drone-flight/

 

[LoneRCRanger]

Renov8r to the rescue. I viewed that page and it explains it very well. Thanks Guy!

 

[HiDesertHal]

Ah HAH! That corroborates what I was thinking all along!

Thanks for that link, RENOV8R...it explained everything that juggling the motor speeds can do!

I never thought of motor torque differences producing yaw movements!

Thanks, guys!
Hal