Building Wind Vibration Monitoring System Design Based On Quasi-Synchronous Over-Sampling Technology

With continuous development of science and technology,the height and quantity of super-high-rise buildings in our country have increased sharply at present.The characteristics of high-rise buildings are complex structure,low damping,wind vibration such as wind has a great impact on high-rise buildings,so wind vibration monitoring is particularly important.In this design,piezoelectric sensor is used to design a building wind vibration monitoring system based on quasi-synchronous oversampling technology to monitor building vibration caused by strong wind.At present,the price of vibration monitoring instrument is very high.Affected by the international situation in recent years,the chip supply chain is limited,and the price has increased greatly.It is urgent to re-design and implement the domestic instrument,make full use of the existing MCU resource allocation technology,eliminate the external ADC,and improve the circuit integration.A signal acquisition circuit without external synchronous acquisition chip is designed and implemented.Different sensors can be used in different scenarios.The PVDF sensor and low-cost signal acquisition circuit can be used to monitor the wind vibration of buildings without providing external excitation.The requirement of building monitoring circuit is that there are many collection points and the sampling rate is not high.A low-cost circuit implementation method is designed,which uses single-chip MCU for multi-channel configuration and relies on the 16 bitADC integrated by MCU in stmicroelectronics to configure multiple sampling channels.An eight-channel data acquisition configuration scheme is selected for hardware circuit design.At the same time,a multi-module synchronous triggering building monitoring scheme based on GPS/BDS dual mode is proposed to meet the needs of multi-floor vibration monitoring of high-rise buildings.The circuit of the building monitoring system is mainly composed of programmable gain amplifying circuit(PGA),signal conditioning circuit,trigger circuit and power circuit in the analog part.Digital part of the microprocessor(MCU)minimum system,GPS/BDS dual-mode satellite timing circuit,large capacity memory circuit,interface circuit.The oversampling technique is used to improve the dynamic input range of the signal,and the effective resolution is improved by about 4 bit after 64 times of oversampling.The resolution of ADC mainly depends on the significant digit.The quasi-synchronous algorithm can reduce the phase error of the collected signal and also slightly improve the SNR index during sampling.Use USB and network port to communicate with the upper computer in real time.After testing,the real-time transmission speed can reach 100 kSPS,and the waveform display and data processing can be carried out by the upper computer LabVIEW.The circuit cost of this system is about 500 yuan,compared with the same type of vibration monitoring instrument,greatly save the cost of hardware circuit,to achieve a higher economic and technical index.The hardware circuit of this design has been basically completed,and the necessary functional verification has been carried out.The wind-induced vibration of artificial knocking simulated buildings has been used for data monitoring,and the vibration frequency of the shaking table has been detected,which proves that the scheme is feasible.