The Generation Mechanism Of Irregular Wave In Experimental Tank And The Research Of It Control

Wave has great harm for the ship, harbor engineering and offshore platforms. It is very necessary to study the wave resistance character of marine facilities, with the further development and utilization of marine resources. Marine facilities require to test its character of wave resistance under the design phase in test pool, which can generate waves.Because of complicated marine environment, the traditional wave maker cannot able to meet the existing demand. Nowadays simulate irregular wave is become more and more important in test pool. This paper study and analyzes the theory of slight wave, Stokes wave, elliptic cosine wave, solitary wave, focused waves, oblique wave spectra and so on. By studying the curve of wave, the motion state and the trajectory of water particles, we study the generation mechanism of irregular wave and water particle trajectory. In this paper, taking paddle wavemaking style, and establishment the hydrodynamic model of the interaction of paddle and water, derived its motion formula based on the constant volume principle. Meanwhile, combine the generation mechanism of different kinds of wave and the movement of paddles, get motion trajectory equation of the plate of different kinds of wave.This paper designed and built 7-axis paddle style wave-maker. Using AC servo motor driven ball screw reciprocation, in order to achieve the control of paddle trajectory, and generate different kinds of irregular waves. Experimental platform taking full closed-loop control strategy, EtherCAT fieldbus, Beckhoff TwinCAT software, taking the control mode that "soft PLC" combine with the IPC to develop the wave-motion control system, and programing. At the same time taking electronic cam editor, convert plate motion trajectory equations of irregular wave to control signal, achieve plate motion controlBy wave-making experiments confirmed the formulation of wave generate and the motion of plate, which based on Volume invariance principle; The simulation of irregular waves in test pool, Due to the imitations of test pool size, the actual results of some special waves is not very good.