Design Of Multi-channel Strain Data Acquisition Instrument For High-speed Maglev Transportation System

Strain measurement technology plays an important role in the research phase of maglev transportation system.In order to understand the load distribution of maglev transportation system and to provide data support for the verification of system index,strain measurement is required at key locations of maglev transportation system load such as support wheels and guide wheels.In this paper,we design a multi-channel strain gauge for high-speed maglev transportation system based on the strain testing requirements of the pilot phase of the "Ultra-high-speed low-vacuum maglev transportation" project.Based on the research of traditional strain acquisition equipment,this paper designs a multi-channel strain gauge for high-speed maglev transportation system with FPGA as the main control,and carries out the overall scheme design,hardware and software design,housing design and simulation of electromagnetic shielding of the housing.A high-precision bridge excitation is used to improve the strain testing accuracy and ensure the accuracy testing requirements of the collector.The analog filtering circuit includes RFI filtering and low-pass filtering,while the digital filter is designed with a 15th-order FIR filter module and a distributed design to improve the resource utilization of the FPGA.The strain gage housing is designed for structural and electromagnetic shielding.The electromagnetic simulation of the housing using Maxwell software determines the use of iron and Permalloy as the magnetic shielding materials of the housing,and proposes the electric field shielding measure of applying a layer of copper foil to the inner wall of the housing to make the gage have effective electromagnetic shielding capability.In addition,a local storage circuit and an Ethernet communication circuit are designed to enable the collector to perform real-time storage and remote communication of data.Finally,the function and accuracy of the collector are tested and verified,and the results show that the multi-channel strain data collector designed in this paper can realize the basic functions of acquisition,storage and transmission,and each channel can guarantee 0.5% of acquisition accuracy.