Research On Multi-channel Dynamic Balance Test System Based On Hardware Correlation

In the application of rotating machinery,due to the different support stiffness in the horizontal and vertical directions,the vibration generated in the horizontal and vertical directions is also different in the process of rotation,so it is necessary to select the vibration in different directions.Based on the algorithm of signal frequency correlation,a new multi-channel dynamic balance testing instrument is developed in this paper.The instrument has the function of multi-channel vibration signal acquisition,which can simultaneously detect the unbalance of rotor in horizontal and vertical direction.The main design content of the subject includes the following aspects:According to the test object and design requirements,the overall design scheme of the test system is determined firstly.The piezoelectric sensor is selected to pick up the vibration signals of the rotor in different directions,and the laser sensor detects the speed signals of the rotor.The hardware circuit is mainly divided into two parts.The first part is to preprocess the vibration signal to obtain the vibration signal with certain strength and the same frequency as the rotating speed,including photoelectric shaping circuit,controllable amplification circuit,lock-in frequency doubling circuit,tracking filter circuit,etc.;the second part is the same frequency correlation circuit designed according to the signal correlation principle,which bears most of the difference The balance calculation process makes the test speed faster and more accurate,including level conversion circuit,low-pass filter circuit,Co frequency correlation circuit,etc.The 24 bit data acquisition card designed and produced by Wuhan Yawei company is selected to collect vibration data and upload it to the computer.The test software is also composed of two parts.The first part is to use Visual Basic 6.0 language to write a program to control A / D data acquisition card according to the digital communication protocol,which is the core of the software part;the second part is to process the vibration data,realize the sweep frequency analysis function,and establish the database to store the vibration data,and select the solution point according to the sweep frequency analysis results,so as to calculate The magnitude and position of the unbalance of the measured rotor are calculated and displayed on the corresponding human-computer interface.The interface of test system mainly includes system start interface,main test interface,sweep frequency analysis interface,database interface and exit prompt interface.Finally,the test accuracy and stability of the whole test system are verified to meet the requirements of the standard,and the unbalance of this kind of rotor can be accurately measured.