The Control Algorithm Of Closed-loop Gain Shaping And Its Application To The Rudder Roll Damping System

The control algorithm of closed-loop gain shaping when the controlled object is not square matrix in the SIMO system is developed in this thesis. The application of the control algorithm to the SISO system, the unstable process and the MIMO system whose controlled object is square matrix has been affirmed fully. However, it is very difficult that the controller is designed when the controlled object is not square matrix, because it is involved in the pseudo inverse of matrix. The closed-loop transfer function matrix of such a system must be singular and an input controls two outputs in the system, so the closed-loop transfer function should be assumed a singular matrix whose elements are the fist-order inertia components, then the controller is designed.The control algorithm of closed-loop gain shaping is applied to the rudder roll damping system (RRD). The rudder roll damping system is just the system whose controlled object is not square matrix. The input is rudder-order and the outputs are the roll angle and the heading angle. The input controls the two outputs.The model of RRD is linearized to a fifth-order linear one, and then is reduced to a second-order one. With the algorithm, a low-order controller can be got. The nonlinear mathematics model of RRD is researched and established, and is realized by programming in Matlab. The controller designed is applied to the fifth-order linear model and the nonlinear one, and then simulated by Simulink. The control performance is excellent.In order to enhance the reliability of the simulation, the wind and wave model are added to the nonlinear system. The course keeping and the course tracking are well. Through observing, analyzing and comparing the simulated curves with damping and those without damping, the roll reduction can reach 25% or so.Because of the excellent control performance and robustness, the algorithm is worth studying and applying.