船舶柴油机数字化监测与诊断系统

介绍了基于虚拟仪器技术的船舶柴油机数字化监测与诊断系统的设计与实现技术,分析了柴油机主要子系统的参数测量、分析和管理等子模块.实验室试验结果表明,可以用该系统实现柴油机多参数多方法的综合监测与故障诊断.     

Comparison of vibration response prediction on the main deck of a catamaran using experimental,numerical and correlated mode shapes

This work analyses the influence of three types of modal matrices on the prediction of vibration response (virtual sensing), at unmeasured degree of freedoms (DOFs), on a catamaran’s main deck: (1) uncorrelated finite element (FE), (2) correlated FE and (3) experimental modal matrices.A multi-objective genetic algorithm (MOGA) framework was developed to handle the optimization and prediction processes. This framework introduces a new metric called Time–Frequency-Error Response Assurance Criteria (TFERAC) to assess the prediction quality. This metric also allows estimating the best set of modal acceleration vectors, which is a critical step in the virtual sensing process.As a case study, only 06 accelerometers and 13 vibration modes (within each modal matrix) were used in the virtual sensing. The MOGA framework’s performance was evaluated using a variance analysis test (ANOVA) between measured and predicted response signals.Results showed that: (1) any one of the modal matrices could be used successfully for virtual sensing on the main deck, that is, there is no need to use correlated FE or experimental modal matrices; (2) the newly proposed metric TFERAC leads to smaller errors in the prediction of both vibration time series and vibration spectra;(3) it is possible to perform a virtual sensing on a ship’s main deck using a limited number of sensors and a numerical modal matrix without being correlated with experimental data.     

激光测量技术在船舶舾装中的典型应用

从常规测量和高精度测量两个方面,结合与传统手段的对比,介绍激光测量技术在船舶舾装领域中的典型应用,包括应用场景、技术原理、仪器类型和操作方法,总结主要激光仪器的适用特点。激光测量技术相对于传统测量方法具有显著优势,针对船舶舾装的具体任务和环境,选取合适的器材种类,可以获得良好的测量效果。