What does gravity compensation do in flight control? In flight control designs for lateral directional movement, there is a block named &quot;gravity compensation&quot;. This block changes yaw rate measurement from &quot;$r$&quot; to &quot;$r-g/Vcos(\theta)sin(\phi)$&quot; before it is sent to the controller. How does this block change the equation of motion?
That term is a feedforward.
It simply makes sure that during a turn the rudder will anticipate the need for that $r$ component and thus helps making the turn coordinated.
Since the term is complete (i.e. there is also the $\theta$ component) this will work also for climbing/descending turns.