Research On The Key Technology Of Smart Hull Monitoring System

Ship engineering is becoming more and more large and complicated,and it is difficult to make a comprehensive damage diagnosis and evaluation of the hull structure only by manual detection and subjective experience.In order to timely monitor the structural parameter and predicte the trend of structural stress,the hull monitoring technology emerges at the historic moment.The hull structure monitoring system can real-time monitors the stress of the weak parts and make the data analysis and processing to improve the safety performance of hull structure.Based on the requirements of China classification society for intelligent ship construction and hull monitoring system,the modules of data compensation and filtering,slamming load inversion and trend prediction are studied and analyzed.And a prototype is designed.The main contents are as follows1.Based on Butterworth filter,data filtering module of intelligent hull monitoring system is designed and developed,and delay-data and outliers caused by filtering are solved.At the same time,compensation of measurement error caused by temperature deformation is carried out,and a method of measuring coefi-icient of thermal expansion and cold contraction by optical fiber sensor is proposed.2.The identification method of slamning load is designed,the generalized orthogonal polynomial theory is introduced to fit the slamming load,the influence matrix method is studied and the theoretical model is proposed.Through simulation calculation,the influence coefficient matrix of the model is solved,and the slamming loads of the measuring points are calculated.3.The time series prediction method,adaptive filtering method,gray prediction method and peak probability prediction method of ship overtaking probability level method are studied,and the mathematical theoretical model of trend prediction method is proposed.By using the above four prediction methods,the ship model test data are predicted and calculated,and the prediction results are compared to verify its applicability in the field of ship monitoring.4.The ship hull monitoring system including filtering module,temperature compensation module,load inversion module and trend prediction module is designed.Low temperature environmental load test is carried out to verify the temperature compensation function.And large-scale model test is carried out to verify the load inversion and trend prediction.