RU1797726C - Detonation meter - Google Patents

Abstract

The invention relates to a magnetic recording technique, and in particular to devices for controlling the knock coefficient of magnetic recording equipment. The purpose of the invention is to improve the accuracy of measurements. The device contains 1 ADC (1), 1 linear bandpass digital filter (2), 1 shift register (3), 2 adders (4, 5). 1 divider (6), 1 digital weighing filter (7), 1 maximum value determining unit (8), 1 digital indicator (9). 1-2-3-4-6-7-8-9, 3-5-6. 1 ill.

Description

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The invention relates to a magnetic recording technique, namely, to devices for controlling the knock coefficient of magnetic recording equipment.

A device is known for measuring the knock coefficient, in which the knock value is estimated from the absolute value of the frequency deviation, comprising an ADC connected to a digital bandpass filter with a finite impulse response and a converter.

A disadvantage of the known device is a sufficiently long measurement time, low measurement accuracy and a small frequency range of measurement,

A knock measuring device is known which comprises a frequency demodulator, a rectifier, a calibrator, controls, connections and controls.

The aim of the invention is to increase accuracy and extend the frequency range of measurements.

For this, an analog-to-digital converter (ADC) connected to a digital band-pass filter with a finite impulse response and a converter connected to the band-pass filter through shift registers are introduced into the device for measuring detonation.

To clarify the essence of the measurement, we use the following notation:

zi / mind - yi /. X | / uhhhhhhhhh.

In the device, the measurement and processing of the results is carried out in real time, which is possible due to the fact that in the inventive device the samples r and xi are obtained as a result of two subtraction operations that are carried out in parallel (simultaneously). The obtained samples zi and x are added to the previous samples ZM; ZMv xl-a; zi-2 etc. And after carrying out (n - 5) additions, the device divides the sums obtained.

In practice, processing each new sample takes time to carry out only two operations (subtraction and addition). The number n is determined by the required measurement accuracy and the band of measured frequencies.

Claims (1)

SUMMARY OF THE INVENTION An apparatus for measuring detonation, comprising in series an input signal driver, a demodulator with a weighting filter and an indicator, characterized in that, for the purpose of The drawing shows a structural diagram of the device. The device contains an ADC 1, the output of which is connected to a linear strip digital filter with FIR 2. The output of the digital filter 2 is connected to the shift registers 3, the outputs of which are connected through the adders 4 and 5 to the divider 6, In turn, the output of the divider g is connected to a digital weighing filter with IIR 7, the output of which is connected through a device for determining the maximum value of 8 to a digital indicator 9. During operation of the device, a signal reproduced by the tape recorder from the measuring tape, is fed to the input of the ADC 1, where it is converted into a sequence of samples. Next, the signal is passed through a digital bandpass filter with a passband of 2600-3700 Hz, after which it is fed to a digital frequency demodulator made on shift registers 3, adders 4, 5 and divider 6. On adder 4 from shift registers the samples arrive shifted relative to each other by four sampling periods, and to adder 5 - shifted relative to each other by two sampling periods, Thus, in the digital demodulator, a frequency estimate is implemented according to the following formula: n -5 2 / yj + 4 yi / cos (2 lzd -  0 and -5 2 / U1 + s  0 where y are voltage readings; f is the signal frequency; D is the sampling period; n is the number of voltage samples for which the frequency is estimated. Next, the signal from the digital demodulator is fed through a digital weighing filter 7 to a maximum value determination device 8, after which the measurement result is transmitted to a digital indicator 9, on which the measured detonation coefficient is displayed. increasing accuracy and expanding the frequency range of measurements, the input signal shaper is made in the form of a series-connected analog-digital converter and a digital band-pass filter, the demodulator is made in the form of a of the adder-calculator, the sequential block for determining the maximum end-connected shift register, the output of which is the output, the de-input of which is the input of the demodulator-modulator, and the other output of the shift pa, the second adder-calculator, is divisor The register is connected through the first total, a digital weighting filter, an itor-subtractor, and another input of the divider.