船舶进出港低速航向保持

为了在船舶进出港时，船舶处于浅水域并以低速航行，在风、浪等强扰动作用下，增强航向控制性能，减小能源损耗，选择三阶Nomoto模型，将航速和水深变化反映到模型参数的变化上，基于闭环增益成形算法设计出一种具有适应性的鲁棒PID控制器，建立基于风、浪干扰的非线性船舶运动数学模型，并用S函数来实现。用PID控制器对非线性船舶运动数学模型进行控制，在Simulink环境中对各种水深、船速及海况进行航向控制仿真。从仿真曲线可看出其航向跟踪效果良好，静差为0，且施舵合理，所设计的控制器对非线性船舶运动数学模型具有良好的控制性能。

Course-keeping of inward-and-outward low speed ship

In order to improve ship control performance, reduce ship energy consumption when ship navigates at low speed in inward-and-outward shallow water under strong wind and wave disturbance, third-order Nomoto model was chosen, ship speed and water depth were reflected into the changes of its parameters, a robust PID controller with adaptability based on closed-loop gain shaping algorithm was designed. The nonlinear mathematical model of ship motion with wind and wave disturbance was built and realized through programming its S-function. The designed PID controller was used to control the nonlinear mathematical model of ship motion in the conditions of various water depths, ship speeds and sea states. The simulation result shows that the course-tracking effect is satisfactory, the steady state error is zero, the rudder angle is reasonable, and the designed controller has good performance for the nonlinear mathematical model. 2 tabs, 5 figs, 11 refs.