Design and implementation of a measuring system for shipbuilding based on WinCE
The measurement in shipbuilding is an important task of improving the quality and efficiency. Precision industrial surveying and computer technology can be applied to embedded measurement systems, in which the convenient functions of coordinate data collection, assistant calculation and analysis are provided to test shipbuilding quality. In this paper, the process of system design and operation was described in detail, and then the key technologies involved were discussed.
Applications of Lodrigues matrix in 3D coordinate transformation
Three transformation models (Bursa-Wolf, Molodensky, and WTUSM) are generally used between two data systems transformation. The linear models are used when the rotation angles are small; however, when the rotation angles get bigger, model errors will be produced. In this paper, we present a method with three main terms: the traditional ➀ rotation angles θ, φ, ψ are substituted with a,b,c which are three respective values in the anti-symmetrical or Lodrigues matrix; ➁ directly and accurately calculating the formula of seven parameters in any value of rotation angles; and ➂ a corresponding adjustment model is established. This method does not use the triangle function. Instead it uses addition, subtraction, multiplication and division, and the complexity of the equation is reduced, making the calculation easy and quick.
Statistics and damage assessment of ship grounding
Abstract In this paper, general statistics of ship grounding incidents are considered and the damage extent distributions for Ro–Ro ships are presented from the results of a comprehensive damage data survey conducted using Lloyd's Register's damage database. Theoretical models and semi-empirical formulae based on parametric studies are used to study the damage extents of grounded ships. Two real life grounding accidents are assessed. One is a single hull VLCC grounded onto a single rock and the other is a cargo ship grounded onto multiple rocks. A simulation based on a simple multi-rock scenario has been conducted on a 304-m single hull tanker. Correlation is made between the present calculation method results, statistical results and IMO requirements. The paper concludes with the main findings from the study.