Spatiotemporal Deformation Analysis And Visualization Of Bridges Based On Spatiotemporal Kalman

The purpose of deformation analysis is to use mathematical models to predict the deformation trend of the deformed body and provide a basis for the structural health analysis and early warning of the deformed body,so that corresponding measures can be taken in time to avoid or reduce the occurrence of disasters.The traditional deformation analysis methods mainly only consider the time correlation of the monitoring points,but not the spatial correlation between the monitoring points,and cannot make full use of the time and space correlation information between the monitoring points.Spatial analysis methods such as Kriging interpolation and polynomial interpolation only consider the spatial correlation between the monitoring points,but ignore the time correlation of the monitoring points.The use of the Space-Time Auto-Regression model in the field of deformation analysis takes into account the spatio-temporal correlation of the deformable body,but the Space-Time Auto-Regression model can only perform multi-point deformation analysis,not the overall deformation analysis of the deformable body.In order to analyze the global deformation of the deformable body,process the new planar measurement data and improve the prediction accuracy at the same time,this paper improve the Spatio-Temporal Kalman model based on the Spatio-Temporal Random Effects model,and develop a bridge visualization system for deformation analysis results combining the deformation of the bridge.The main research work and results are as follows:(1)Summarizes the current research status of geometric deformation analysis and the existing problems in the current deformation analysis,and concludes that the Spatio-Temporal Kalman based on STRE is a better method for the deformation analysis of massive surface monitoring data.(2)Spatio-Temporal Kalman models based on STRE are Analyzed and compared,which methods of moment estimation and EM iterative estimation establish,with experiment of simulation data,the result points out: Spatio-Temporal Kalman model established EM iterative estimation is a little better than Spatio-Temporal Kalman model established moment estimation in dimension reduction effect,deformation prediction effect of EM iterative estimation is superior to the prediction effect of moment estimation.In the Spatio-Temporal Kalman model based on STRE established by EM iteration estimation,there is no significant difference between Fixed Rank Smooth(FRS)and Fixed Rank Filter(FRF)in dimension reduction effect,while in the aspect of space and time prediction,FRS is slightly better than FRF.(3)According to the characteristics of bridge deformation,a SpatioTemporal Kalman deformation analysis method based on STRE is improved.Considering the vibration phenomenon of the bridge,the vibration period of the bridge is extracted by using the wavelet analysis method,and the amplitude of the corresponding sampling time point is set according to the sampling rate of the monitoring data.The amplitude of the sampling time point within a vibration period is expressed as the form of Kalman filter,and then it is fused with the Spatio-Temporal Kalman model based on STRE.The state transition matrix which changes at any time is estimated by EM iteration segment,and the STRE model with variable state transition matrix is constructed.Simulation experiment and deformation analysis results of bridge ground-base SAR data show that the STRE model of variable state transfer matrix has the same dimension reduction effect as the common STRE model.For the deformation prediction effect of FRS,in the simulation experiment and the bridge data processing,the state transfer matrix variable STRE model is improved compared with the ordinary STRE model.At the same time,FRS of state transfer matrix variable STRE model improves the prediction velocity,However,the FRS prediction effect of STRE model with variable state transition matrix is very close to that of FRF deformation prediction,which indicates that the STRE model with variable state transition matrix can consider using FRF instead of FRS for dimensional reduction and prediction of spatial-temporal data,to avoid the burden of system storage and calculation when using FRS for deformation analysis.(4)According to the results of bridge deformation analysis,a 3D visualization system of bridge deformation based on QT and SQL Sever was developed to realize the 3D display of bridge deck deformation.The software supports the display of bridge deformation analysis data and manmachine interactive operation.