Design And Implementation Of Multi-channel Data Acquisition Device Based On FPGA

Rotary equipment is the key industrial equipment in civil and military fields,including steam turbine,compressor,helicopter rotating mechanism and so on.In the civil field,for rotating equipment such as steam turbine and compressor,the real-time monitoring of the equipment can discover the fault in time and judge whether it can run normally.In the military field,it is necessary to detect and analyze the key components of special rotating equipment in order to judge the performance of the equipment.At present,the research of data acquisition based on rotating equipment has become an important subject in the field of measurement and control.However,as the rotating equipment is developing towards the direction of complexity and intellectualization,its operating environment is becoming more special,and the requirement of acquisition index for accuracy is also increasing day by day.At present,data acquisition devices are often difficult to adapt to its complex electromagnetic environment and can not meet the requirements of rotating environment acquisition.In view of the above situation,this paper designs and implements a data acquisition system based on FPGA,which can be used for 64 analog signals synchronous acquisition.The maximum sampling rate is 200KS/s/ch,and the sampling rate can be set by programming.It is a complete data acquisition system,which adopts highly integrated hardware architecture and can be connected to the host computer through the Ethernet interface.The acquisition system can be installed on rotating equipment and rotate synchronously with it,and can work stably in complex electromagnetic environment.It provides a miniaturized and scalable solution for data acquisition of rotating equipment.Firstly,the engineering background of the collector is introduced.According to the functional requirements,the overall scheme of the collector with the control core of the FPGA is constructed.Its structure consists of the acquisition control board and the core control board.The acquisition control board mainly completes the function of multi-channel signal conditioning and analog-to-digital conversion,and performs noise suppression through RFI anti-radio filter and 6-order Butterworth filter.The core control board completes the data parallel processing and the logical control and timing control of the whole system.The Ethernet module is responsible for the data transmission function of the hardware and the host computer,and the memory module is responsible for the data caching mechanism.At the same time,in order to obtain pure power supply,a sliding-loop filter based on pi-filter is designed.Each board adopts 6-layer PCB cascade structure,and the collector is cylindrical as a whole.Secondly,based on the function modules of the collector,this paper explains how to realize the overall logic design through the FPGA.The design process of data buffer module based on NAND Flash and Ethernet transmission module based on W5500 is introduced.Finally,the test platform is built and related tests are carried out.The actual data acquisition experiments verify that the relevant indicators of the collector can meet high requirements in both static and dynamic acquisition environments: CMRR(≥ 75dB),SFDR(≥60dBc),GA(≤0.1%),PM(≤0.1degrees),which meets the requirements of the rotary equipment data collector for the accuracy of indicators,anti-interference ability and working stability,and verifies the performance reliability of the designed collector.