船舶操纵性约束模测量系统设计与分析

Ship Maneuverability Captive Model Test Measurement System Design and Data Analysis

摘要:

为解决实验室船舶操纵性约束模实验中的测量及数据分析处理技术问题，开发组建实验测量系统，推导数据分析处理方法，以期实现约束模实验的测量与数据在线分析处理。根据前期研究经验，设计了较为完善的测量硬件系统方案；其中为实现约束模中精确的零相位整周期测量要求，采用光电开关利用数据采集卡的硬件触发启动功能来实现，并给出了整数周期测量的方案；利用最小二乘拟合及傅里叶分析等方法推导给出各船舶水动力导数数据处理方法。在此基础上，作为重点编写了完整的在线测量与数据在线分析程序，主要功能内部独立实现；该系统手工介入频度低，基本实现了测量的自动化，效率得到大幅提高。最后展开实际测量验证，数据的拟合结果与测量结果符合良好，验证了本文系统的可靠性；同时处理结果显示船舶附加质量导数Yv同船舶惯性质量很接近，而导数Yr',Nv'数值很小近于零。

Abstract:

In order to solve the practical experiment measurement and data processing problems for ship maneuverability captive model tests, a hardware system is designed and set up, data processing algorithms are derived to obtain the hydrodynamic derivatives on-line. A comprehensive measuring system is developed as well as the measuring schemes; to achieve precise timing at zero-phase angle for starting data acquisition, a high-speed infrared photoelectric switch is employed with the help of the trigger function of the data acquisition card, and a scheme is proposed to ensure integral number of motion period. Utilizing Least-Square-Fitting and Fourier-Analysis methods, data analysis algorithms are derived to fulfill the object of identifying ship maneuverability derivatives. A measuring and analysis software program, as the key object of this paper, is coded, which meets the practical requirements of captive model tests with satisfaction, its main and elementary functions are implemented internally with little outer dependency, the program requires little human interference and achieve an agreeable level of automation. Model experiment is carried out to demonstrate the hardware and software system, which yields agreeable results. Meanwhile, the results show that the ship’s derivative Yv is pretty close to its inertial mass, and the derivatives Yr',Nv' are a minor value.