Frequency dividing detector for feedback control of low frequency electromagnetic vibration table system

Abstract

The invention discloses a frequency division detector for feedback control of a low frequency electromagnetic vibration table system. The frequency division detector comprises a comparator, a counterand a frequency controller connected in sequence. The system input signal and the reference input signal of the driving vibration table system are input to the comparator, and the comparator outputs asquare wave signal formed by the system input signal and the reference input signal. The square wave signal is input to the counter together with the pulse signal of the known frequency. The countergives the number of cycles of the system input signal Nf and the number of cycles of the pulse signal of the known frequency Ns, and inputs the number of system input signal cycles and the number of reference input signal cycles to the frequency controller, and the frequency controller calculates the frequency value of the square wave signal ff. The frequency dividing detector is shown in the description, where fs represents the frequency value of the pulse signal of known frequency. The frequency division detector is capable of identifying the current operating frequency of the vibrating table with high motion control accuracy.

Description

technical field [0001] The invention relates to a low-frequency electromagnetic vibrating table system. Background technique [0002] The electromagnetic vibrating table has the advantages of wide frequency range, good controllability, and high output waveform accuracy. It is widely used in the fields of simulated vibration environment test of products, vibration sensor calibration and so on. In order to further improve the accuracy of the output waveform of the vibration table in the low frequency range (reduce the degree of distortion), it is usually necessary to build a negative feedback control system. Negative feedback control first needs to detect the output vibration signal of the electromagnetic vibrating table through a vibration sensor (acceleration, speed or displacement sensor) or other motion detection devices, and then use this signal as a feedback signal to calculate the difference with the input signal, and the deviation signal passes through the controller ...

AI Technical Summary

Problems solved by technology

[0005] 1. Since the equivalent DC resistance R of the driving coil of the vibrating table cannot be accurately measured, the parameter K in the relative speed extraction device 1 2. The device extracts the motion of the vibrating table by constructing an analog circuit network. Since a resistor needs to be connected in series in the drive circuit, the heat loss is large, so it is not suitable for Vibration table with high acceleration output

In addition, the system is more complex, and the low-frequency noise of the analog circuit will cause low-frequency drift of the vibrating table during motion, which reduces the motion accuracy

3. The output signal of the relative speed extraction device depends on the parameters of the driving coil. Since the number of turns of the driving coil is limited, the output voltage reflecting the relative speed is relatively low, especially in the lower frequency band, which affects the control effect

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