Research On Vibration Signal Measurement Method Based On FPGA

The vibration signal is one of the important signals that characterize the motion state of the rotating machine.In this paper,by studying the signals of common faults in rotating machinery and their fault characteristics,the system based on Field Programmable Gate Array are designed which aims to measurement and acquire and process the vibration signal.Then the experiment of simulating mechanical vibration is designed to verify the advantage of the vibration signal acquisition based on Field Programmable Gate Array equal angle sampling.The advantage of the processing system,compared with the system of vibration signal acquisition and processing based on equal time sampling,the application of Field Programmable Gate Array in the analysis,acquisition and processing of mechanical vibration signals can make the signal acquisition and procedure simple and the processing result more accurate.First,the characteristics of common mechanical faults and their fault signals theoretically study as well as signal processing methods.An instantaneous speed measurement method based on Field Programmable Gate Array is proposed,as well as the order analysis method of equal time sampling,the order analysis method of equal angular based on Field Programmable Gate Array.Secondly,the rotational speed,vibration signal period measurement,vibration signal order analysis experiment of rotating machinery are designed,and the signal acquisition and processing program is designed according to the experimental requirements.The experiment is based on National Instruments LabVIEW and its sound and vibration module,signal processing module module,Field Programmable Gate Array module,RT module as the main software,cRIO 9025 real-time controller,NI 9234,NI 9411,NI 9201 and other hardware.The signal generator is used to simulate the encoder to send out various vibration signals.The NI 9411 is used to perform equal-angle interval sampling and instantaneous speed measurement.The NI 9201 and the NI 9234 is used to perform sampling at equal time intervals.Finally,the host computer reads and processes the signal.Finally,the rotating machine vibration experiment is simulated.The results of the instantaneous speed experiment show that the Field Programmable Gate Array-based equal angle sampling can improve the accuracy of the instantaneous speed measurement.At the same time,the Field Programmable Gate Array can increase the clock frequency by multiplying the frequency,and the accuracy of the instantaneous speed measurement can be further improved.The experimental results of the instantaneous speed measurement error indicate that the instantaneous speed measurement based on the Field Programmable Gate Array-based equal-angle interval has the advantages of short running time and small fluctuation of the measurement speed.