Analysis of the Design of Stability Loop Affected by Nonlinear Characteristics of Servo Valve Dead-Zone of Rudder

According to nonlinear characteristics of servo valve dead-zone, the method of combining describing function and mathematical simulation is used to analyze the impacts on the design of stability loop. The result shows that the dead zone characteristics will lead to 0. 5-2Hz low-frequency oscillation. The way of designing the control parameters in reason and reducing dead-zone can alleviate the oscillation phenomenon, which contributes to system stability. Furthermore, the amplitude and frequency of system oscillation are irrelevant to the input signal.