Vibration Signal Acquisition And Eigenvalue Calculation Based On FPGA

Vibration signal monitoring has been widely used in structural health monitoring systems for large-scale civil infrastructure projects due to its high efficiency,reliability,low cost and non-invasiveness.By analyzing the vibration signals,the extracted feature values can provide early warning,so the monitoring staff can perform timely maintenance on the facility.On the basis of understanding the research status at home and abroad,this paper develops a FPGA+ARM multi-channel vibration data synchronous acquisition system.This paper realized the effective calculation of dynamic displacement eigenvalues based on the hardware platform designed in this paper.The main contents are as follow:1.This paper determines the hardware achieving plan of the multi-channel vibration data synchronous acquisition system,which is consist of two parts: one is the data acquisition and control unit based on EP4CE15F23C8,and another is the data processing unit based on STM32F407IGT6.The hardware platform includes micro controller part,electric power part,signal acquisition and conversion part,backup memory device part,and communication part such as Ethernet.2.Completed the software design and debugging of the acquisition system.Using FPGA to realize the synchronous sampling,sampling frequency switching and data buffering of highspeed signals;using ARM to realize the backup storage in the form of files and data upload in multiple communication methods.Combined with the designed hardware platform,this paper finally realized the online,stable and synchronous sampling of 12 channels.3.For dynamic displacement calculation,this paper proposes a method that combines fast Ensemble Empirical Mode Decomposition and time domain integration.Through the FEEMD algorithm,the acceleration,velocity,and displacement signals are decomposed and reconstructed,which effectively filters out the low-frequency trend terms and high-frequency noise that cause integral drift.On the data acquisition system platform developed in this paper,the proposed algorithm is verified based on a variety of experimental scenarios.Compared with the three methods in the cited literature,the effectiveness of the proposed method has been verified.4.Based on the multiple filtering and double integration,the dynamic displacement calculation is realized on the FPGA hardware platform.High-pass filtering and low-pass filtering are used to filter out most of the interference terms in the integration process.The effectiveness of the method is verified by signal simulation experiments.Compared with the FEMMD adaptive filtering method proposed in this paper,the advantages and disadvantages of this method in engineering applications are summarized.