The front stretcher adopts magnetic powder breaker to provide linear tension, to solve the relative slip between conveyor belt and damping roll;

For the aircraft with moderate swept wing, the main reasons of causing wing rock are the variations of roll damping moment with the Angle of attack and the sideslip Angle.

The concept of roll energy decay function is put forward, and the nonlinear damping coefficients are solved based on the minor error between actual energy function and evaluated energy function.