Basic study on maximization of the power take off efficiency of oscillating body type wave energy converters.

本研究的目的是使振荡体型波能转换器的功率输出效率最大化。本研究包括三种研究。首先是对贝叶斯模型的改进，该模型通过分析船体的振荡来估计海况。具体而言，将响应函数的误差引入贝叶斯建模，并引入离散小波变换。二是研究了一种浮筒式点吸振器的动态振动控制系统。升沉运动的固有频率由轴向滑动阀控制。第三个研究是利用自参数激振系统进行动态控制。在时域数值模拟的基础上，证明了在不规则波中利用自参数激励振荡的可能性。因此，可以认识到本研究的目标已经实现。

The objective of this study is maximization of the power take off efficiency of oscillating body type wave energy converters. This study consists of three kinds of research. The first one is improvement of the Bayesian modelling that estimates the sea state by analyzing the oscillation of the body. Specifically, errors in response functions were taken into the Bayesian modelling and the discrete wavelet transform was introduced. The second research is development of a dynamic oscillation controlling system of a spar-buoy type point absorber. The natural frequency of the heaving motion is controlled by axial-sliding valves. The third research is utilization of the auto-parametrically excited oscillation for the dynamic controlling system. Based on the numerical simulations in time domain, the possibility of utilization of auto-parametrically excited oscillation in irregular waves was shown. Therefore, it can be recognized that the objectives of this study have been achieved.