Dynamic Inverse Control of Rudder Roll / Yaw Stabilization Based on Rudder Saturation Constraint

An adaptive dynamic inverse control method with input constraints was proposed to solve the problem of steering gear saturation caused by large rudder movement in the process of rudder damping. Firstly, the ship roll/yaw system is decoupled into two subsystems according to the different response frequencies of roll and yaw to rudder. Then, the hyperbolic tangent function is used to constrain the actuator input to reduce the amplitude of steering gear and avoid the saturation of steering gear. After that, aiming at the nonlinear, strong coupling and unknown interference characteristics of ship rudder roll/yaw stabilization system, the roll and yaw control rates are designed respectively by nonlinear dynamic inverse control method, the constraint errors and environmental interference are estimated by combining the adaptive law. Finally, the bounded stability of the closed-loop system is proved by constructing Lyapunov function. The simulation results under different sea conditions show that the designed controller not only has good anti-roll effect, but also can effectively reduce the control input and avoid the saturation of steering gear.