Multi-channel Strain Detection System For Pressure Vessel

Pressure vessels are widely used in the field of industrial production.Structural damage occurs on the surface of the vessels,and the strain data at the corresponding position will also appear abnormally.In this paper,a complete multi-channel synchronous acquisition system is designed for the needs of pressure vessels strain detection.The acquisition system is composed of hardware design,slave computer software design,and master computer software design.According to the different strain range of the container,the hardware acquisition scheme of the acquisition system is divided into two types.For pressure vessels with large strain range,carbon nano paper is selected as the sensor in this design.The acquisition scheme is designed to convert the resistance signal of the carbon nano sensor into voltage signal for sampling and quantification through constant current source circuit.For pressure vessels with small strain range,resistance strain gauge sensors are used in this design.The acquisition plan is designed to convert the strain signal into small changing voltage signal by using a Wheatstone bridge to perform sampling and quantification work subsequently.The hardware design of the acquisition system mainly realizes functions of signal conditioning,filtering,amplification,analog signal sampling,analog signal to digital signal conversion,data processing,storage,and data transmission.This design uses single-chip microcomputer GD32F407 as the main control chip to realize the control of each functional module.Multiple domestic A/D chips called cl1606 are used to realize multi-channel synchronous analog-to-digital conversion function.Micro SD card is used to realize data storage function.LAN8720A is used to realize data network protocol transmission.The software of the slave computer realizes a variety of functions.It mainly includes the design of A/D chip driver,the design of data processing and filtering algorithms,the design of data storage functions,and the design of UDP data sending functions.Among them,SD card data storage is realized by transplanting FATFS file system,and UDP data transmission is realized by transplanting LWIP protocol.The master computer of the acquisition system is designed with LabVIEW software,which displays real-time resistance,strain curves,and also saves the data in a text file format.Finally,through experiments,the power supply stability,response uniformity of each channel and the acquisition accuracy of the acquisition system designed in this paper are analyzed to verify the effectiveness of the design in this paper.