Design and Data Analysis for Ship Maneuverability Captive Model Test Measurement System
To solve the practical experiment measurement and data processing problems for ship maneuverability captive model tests,a hardware system is designed and developed,data processing algorithms are derived to obtain the on-line hydrodynamic derivatives.According to previous research experience,a comprehensive measuring system is developed as well as the measuring schemes;to achieve precise timing at ze-ro-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 the integral number of motion period.Utilizing least-square fitting and Fourier analy-sis methods,the data analysis algorithms are derived to fulfill the object of identifying ship maneuverability derivatives.As the key object of this paper,the measuring and analysis software program is written,which meets the practical requirements of captive model tests with satisfac-tion,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.The model experiment is carried out to demonstrate the hardware and software of the system,which give the agreeable results.Meanwhile,the results show that the ship's derivative Yv is very close to its inertial mass,and the derivative values of Y'r,N'v are very small,close to zero.
ship maneuverabilitycaptive model testPMMFourier analysisleast square fittingdata acquisition