SU1497720A1 - Adaptive filter - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to improve the accuracy of filtration. The adaptive filter comprises an adder 1, adjustable amplifiers 2 and 3, D / A converters 4 and 5, adjustable voltage dividers 6 and 7, integrators 8 and 9, and a reference period measuring unit (BI) 10. The goal is achieved by improving the accuracy of filter tuning at the signal frequency. The filter of clause 2 of the file is distinguished by the implementation of BI 10. 1 C.p. f-ly, 1 ill.

Description

The invention relates to radio engineering and can be used to filter a signal functionally related to the level of vibrations and unbalance of rotating objects.

The purpose of the invention is to improve the accuracy of filtering by increasing the accuracy of filter tuning on the signal frequency "

The drawing shows an electrical adaptive filter circuit diagram.

Adaptive filter contains adder 1, first 2 and second 3 adjustable amplifiers, first 4 and second 5 digital-to-analog converters (D / A) first 6 and second 7 adjustable voltage dividers, first 8 and second 9 integrators, unit 10 measuring the period of the reference A signal containing a photoelectric converter 11, a generator of 12 pulses, a synchronous driver of 13 pulses, a key 14, a counter 15, a buffer register 16 and a decoder 17, a signal input 18, a reference signal input 19, a control input 20 and the first 21 and the second 22 outputs

Adaptive filter works as follows with

When the object under study is rotated, the photoelectric converter 11 perceives a contrast mark deposited on the surface of the object. the generator 12 pulses through the key 14 are fed to the input of the counter 15, the output of which is connected to the information input of the buffer register 16. For each signal differential signal of the photoelectric generator 11, the synchronous driver 13 connected to the e-th output generates a short pulse synchronously with the generator frequency 12 “On the leading edge of this pulse, the information from counter 15 is entered into the buffer register 16, and on the falling front - the counter is reset to 15 At low frequencies, when the period duration is large and long The measurements of the counter 15 are not enough; when the log appears in all its bits, 1 at the output of the decoder 17 appears a log level with O, when the input of which to the control input of the key 14 occurs, the passage of impulses to the input counter 15. In the buffer register 16, all units are rewritten, and the cut-off frequency of the adaptive filter on the second output 22, which is the output-low frequency, is set as low as possible and does not change until the rotation frequency of the object increases will enter d The measurement range of the counter is 15. Thus, at the output of the buffer register 16, which is the output of the reference period measurement unit 10, a signal is generated that is proportional to the reference signal period, whose frequency is proportional to the object rotation frequency o

The test input signal, which may be a signal from the output of an unbalance sensor or a vibration sensor, is fed to the first input of the adder 1, which is filled with a 1–1 input from the actual input of the adaptive 1; Iltrao The frequency of its setting on the first output 21, is it the output of the bandpass filter, and the cut-off frequency of the low-pass filter at the second output 22 is determined by the parameters of two chains; the first chain contains the first adjustable amplifier 2, the first DAC 4, the first adjustable divider 6, the second - the second adjustable amplifier 3, the second DAC 5 and second control; l11 divider 7 Moreover, the variation of matrices of the second DAC 5 and first DAC 4 occurs simultaneously under the control of the code from the output of the buffer register 16 of the reference period measurement unit 10, and the division ratio of the controlled dividers 6 and 7 voltages - under control of a signal from control input 20 "With a constant signal at control input 20, the tuning frequency of the bandpass filter and the cut-off frequency of the low-pass filter can be equal to the frequency of the reference signal when changing the latter in a wide range determined by the width of the applied first and second D / A converters 4 and 5. Such an adaptive filter operation mode can be used when measuring the unbalance signal. At the same time, the phase shift of the signal;: and at the input and output of the filter remains constant throughout the entire tuning range. A change in the control signal at control input 20 can in turn, over a wide range, shift the tuning frequency of the bandpass filter and the cutoff frequency of the low-pass filter relative to the frequency of the reference signal. However, this tuning frequency still changes synchronously with the frequency of the reference signal, Tov rotation frequency. This mode of operation can be useful when measuring the vibration of a rotating object, as it allows you to monitor the amplitudes of the harmonics of the input signal.

Claims (1)

Invention Formula 1o Adaptive filter containing the adder, whose input is the signal input of the adaptive filter, as well as the first and second integrators, the first adjustable voltage divider and the first adjustable amplifier, characterized in that, in order to increase the filtration accuracy by improving the accuracy of the filter tuning at the signal frequency, First, the period measurement unit of the reference signal, whose input is the input signal of the adaptive filter reference signal, has been entered; the first digital-to-analog signal  Q 1497720 A voltage divider whose output is connected to the input of the second integrator, and a control input is connected to the control input of the first adjustable divider and is the control input of the adaptive filter, and a second digital-to-analog converter, the reference input of which is connected to the output of the second adjustable time, the signal input is connected to the signal input of the first digital-to-analog converter, and to the output of the period measurement unit of the reference signal, and the output is connected to the control input of the second controlled signal The output, the output of the second integrator, which is the output of the adaptive filter, is connected to the third input of the adder, and the output of the first variable voltage divider is connected to the input of the first integrator. 2. Filter POP.1, characterized in that the reference period period measurement unit comprises a series-connected photoelectric converter, whose input is the input of the reference period period measurement unit, and synchronous the converter, the reference input of which is a pulse shaper, is subsequently connected to the output of the first adjustable amplifier and to the input of the first adjustable voltage divider, and the output is connected to the control input of the first adjustable amplifier, the signal input of which is connected to the output of the adder, connected in series to the second adjustable an amplifier, the signal input of which is connected to the output of the first integrator, which is the first output of the adaptive filter and to the second input of the adder, and the second regulator 5 0 connected pulse generator, the output of which is connected to the second input of the synchronous pulse driver, a key, counter and buffer register, the control input of which is connected to the control input of the counter and the output of the synchronous pulse driver, and the output of the reference signal period measuring unit and also a decoder, the input of which is connected to the output of the counter, and the output is connected to the control input of the key.