Design Of Ship Motion Control Platform Controller

With the help of continuous development of the world trade, the marine transportation is developing fast day after day, reflected from the type and the number of vessels tremendous changes. At the same time, the requirement of ship motion control is increasing, and various algorithms of ship motion control and dynamic positioning are emerging one after another. The berthing maneuver is very delicate and difficult but important phase in ship's navigation. It is more difficult and more complicated than ever with the appearance of huge vessels and the decrease of crew on board. Thus the problem of automatic berthing is an open one in ship control. Currently, control algorithms of ship motion are mainly focused on computer simulation, with existence of significant limitation. The platform on ship motion control is used to solve this problem.The platform on ship motion control is composed of an industrial computer of PC 104, stepping motor group and the driving system, laser range sensors and four orbits. It is used to simulate the ship's movement in the wave disturbance. The simulation platform is used to validate the applicability of various control algorithm of steering gear in the wave interference. Compared with simple computer simulation and other simulation platform, the advantage of this platform is that ship simulation layer and wave simulation layer are separately controlled by two industrial computers. Because the models are independent of each other, the results of the simulation are more convincing.This thesis is done with the oretical basis provided by a large amount of simulation work in the world. The hardware structure of the ship motion control platform is introduced first, followed by the wave parameters and its mathematical model, and next the ship for the wave response function is derived. Following, the discretization of the displacement and velocity response function is done. The stepping motor driver is controlled by pulses of different frequencies generated by PC 104, corresponding to the discreted velocity response function. Finally, response of the ship on waves is reflected from the wave disturbance layer, with realization of the disturbance to the upper layer, and the purpose of testing algorithms is achieved at last.