Robust Control Of Course-changing For Ships Based On VB Simulation

The research of course-changing for ships is important in the ship motion control; many experts do a lot of effective work. In all of the control methods, Closed-loop gain shaping algorithm based on robust theory can control ships for the course-changing preferably. This method is simulated successfully by MATLAB. Because MATLAB can't be applied into actual engineering directly, the course-changing for ships is carried out by VB in this paper. This paper makes a foundation for an actual engineering application of closed-loop gain shaping algorithm.This paper uses the nonlinear-Norrbin six-degree of freedom motion equations for ships. Calculating the K, T maneuverability index by experiment of simulation. In design of the controller, the PID parameters are calculated using H_∞ robust theory and closed-loop gain shaping algorithm to make the controller robust. the effect of wind and wave is considered to improve the simulation, this paper calculates the rudder of keeping course and decreases the negative effect of wind and wave by precompensation. In the part of programming, in order to improve the efficiency of experiment, some new functions such as calculating the radius of turning circle are added.Through simulation, the results are satisfactory. In the part of ship course control, because of adopting closed-loop gain shaping algorithm, the ship can arrive the setting course quickly without overshoot; after adding the precompensation, the ship can be controlled with the wind of beaufort No.7; in the process of changing course, making the motion of ship reasonable by smoothing the setting course.This paper simulates the ship motion by VB. The controller is robust and the motion of changing-course is satisfactory. By modification of the program, the whole program is easy to read and to amend; the circumstance is more operable and more convenient to the user.