Abstract:This paper first establishes the mathematical model of the drive gap, including the hysteresis model and dead zone model, and analyses the influence of the drive gap on the stability of the system. Second, the describing function method is used to study the nonlinear system with a transmission gap, which reveals the mechanism of self-oscillation caused by the drive gap. On this basis, the effects of the drive gap on the frequency and amplitude of system self-oscillation are discussed under different control algorithms. Finally, a strategy to suppress the self-oscillation caused by the drive gap by adjusting the parameters of the control algorithm or reducing the gap to improve the accuracy by adding shims, etc., is derived, which provides a theoretical basis for improving the stability and accuracy of the rudder.