Development Of Vibration Signal Acquisition And Analysis System Based On FPGA

Rotary machinery equipment is the key equipment in power,aerospace,machinery manufacturing and other important fields.It is developing towards the direction of automation,precision and complexity,and the requirements for its safety and reliability in industrial production are further increased.Vibration signal detection technology is one of the most widely used technologies in the field of health monitoring of rotating machinery structures.It has the advantages of strong detection ability,strong adaptability,strong reliability,low detection cost and non-intrusion.Vibration signal acquisition and analysis system is the foundation and premise of vibration signal detection technology,and plays a pivotal role in the whole vibration signal detection technology.In this paper,a vibration signal acquisition and analysis system based on FPGA is developed.The main research contents include:(1)Design of IEPE piezoelectric acceleration sensor.In order to improve the antiinterference and integration of the piezoelectric acceleration sensor,an IEPE piezoelectric acceleration sensor was developed in view of the current situation of the vibration signal detection of rotating machinery.Based on the research and analysis of the piezoelectric effect theory,the working principle of the sensor and the performance index of the sensor,the planar shear sensor module structure is selected.According to the structural characteristics and material properties,the materials of the piezoelectric element and other components are selected.A two-wire IEPE circuit based on MOS tube is designed.Finally,the sensitivity of the sensor is calibrated and its lateral sensitivity and long-term stability are tested.(2)Hardware design of vibration signal acquisition and analysis system.In order to meet the requirements of vibration signal acquisition equipment for multi-sampling channels,adjustable sampling frequency,high sampling accuracy,high transmission speed and high system integration,a hardware board of vibration signal acquisition and analysis system based on FPGA is designed.The hardware circuit includes signal conditioning module,analog to digital conversion module,FPGA main control module,gigabit Ethernet communication module and system power supply module.The design process includes chip selection,circuit schematic design,PCB layout,PCB production and debugging of each module function.(3)Software design of vibration signal acquisition and analysis system.Aiming at the requirement of real-time acquisition and on-line analysis of rotating machinery vibration signal.The lower computer Verilog program and upper computer LabView software of vibration signal acquisition and analysis system are designed.Verilog program includes data conversion module,RAM cache and control module,gigabit Ethernet communication module and interactive logic control module.The analysis and synthesis of Verilog program and timing constraints were completed,and the simulation was carried out by online logic analyzer(Signal Tap),and the verification function of FPGA internal logic waveform was realized.The upper computer LabView software completes the reading,calculation,storage and display of the collected data,realizes the time-frequency domain analysis of the vibration data and the configuration of the parameters and acquisition mode of the hardware board of the system.(4)Test verification and integrated packaging of vibration signal acquisition and analysis system.The system test platform was built.The vibration signal acquisition and analysis system power stability,system power consumption,gigabit Ethernet communication,acquisition channel dynamic range,no spurious dynamic range and system temperature environment adaptability were tested.At the same time,the portable integrated package of the system is completed,and the rolling bearing fault vibration signal detection experiment is carried out based on the rotating machinery fault diagnosis simulation platform,verifying that the system can be applied in the field of rotating machinery vibration signal detection and fault diagnosis.Based on the requirements of vibration signal detection of rotating machinery,this paper studies and designs a vibration signal acquisition and analysis system based on FPGA with a synchronous eight-channel sampling rate of 100kSa/s and a sampling accuracy of 24bit.The dynamic range of the acquisition channel is greater than 100dB,the dynamic range of the nonstray is no less than 60dB,and the temperature environment is well adapted.The power consumption is only 3.36W.Portable packaging system volume is 430mm*360mm*180mm,weight is 10.8kg,battery power actual life is 16h.In addition,an IEPE piezoelectric acceleration sensor with planar shear structure is developed,and an internal two-wire IEPE circuit composed of only 8 tiny components is designed.The overall volume of the sensor was controlled at 13mm in diameter and 20mm in length.It has a typical sensitivity of 9.8mV/m/s2 with high anti-interference,small transverse sensitivity and high long-term stability.Based on the test results,the vibration signal acquisition and analysis system has realized the functions of sensing,sampling,transmission,analysis,display and storage of vibration signals of rotating machinery,which can meet the requirements of vibration signal detection and analysis of rotating machinery equipment.It has obvious advantages in portable and complex interference working scenes,and has practical industrial application value.