SU1381556A1 - Device for counting moving objects - Google Patents

Abstract

The invention relates to non-destructive testing based on the use of the properties of physical fields, in particular to electronic counting devices, and can be used primarily in water and semiconducting media to account for moving objects of both living and non-living nature. The aim of the invention is to increase the accuracy of counting. The device for counting moving objects contains a pulse generator 1, a shaper 2 W-1 pulses, a repeater 3, a sensor 4, an amplifier 5, a phase-sensitive detector 6, a controlled phase shifter 7, a multiplier B, an integrator 9, a comparator 10 and a recorder 11. Composition The first and second transmitters 12 and 13 and the receiving electrode 14 enter the sensor. The advantage of the device in comparison with the known ones is that the use of complex signals and their correlation processing can significantly improve the sensitivity and allow conductive capacity by improving the signal / noise ratio and the effect time compression when correlation processing. In addition, this device has no effect of environmental conductivity fluctuations on the counting accuracy. 1 hp f-ly, 1 ill. 00 00 ate JV O5

Description

The invention relates to non-destructive testing means, based on the use of the properties of physical fields, in particular to electrical counting devices, and can be used mainly in water and semiconducting media to account for moving objects, both living and non-living. of nature.

The purpose of the invention is to improve the accuracy of the account.

The drawing shows a functional diagram of the device for counting (of the living objects.

The device comprises a pulse generator 1, a pulse driver 2, a repeater 3, a sensor 4, an amplifier 5, a phase-sensitive detector 6, a controlled phase shifter 7, a multiplier 8, an integrator 9, a comparator 10 and a recorder 11.

Sensor 1 contains the first 12 and second 13 transmitting electrodes and the receiving electrode 14.

A pulse generator 1 serves to generate a clock frequency signal, for example, of a sinusoidal or rectangular shape. Any appropriate standard generator can be used in the device, as well as made on the basis of integrated circuits according to well-known circuits.

Shaper 2 converts the clock signal into a complex signal, the base of which is significantly greater than one. The circuit implementation of the former 2 complex signal depends on the type of signal.

The repeater 3 is designed to match the output impedance of the signal converter 2 with the resistance of the medium between the transmitting electrodes 12 and 13.

The transmitting electrodes 12 and 13 form an electromagnetic field in the controlled area and can be made in the form of cylindrical rods of metal or graphite.

The receiving electrode 14 serves to measure the potential of the electromagnetic field. The main requirement for the receiving electrode is a low level of self-noise.

The amplifier 5 is a cascade with a high input resistance, the output voltage of which is proportional to the potential

five

0

B

0

five

0

five

B

0

the magnetic field at the location of the receiving electrode and can be implemented by limescale based on field-effect transistors or integrated circuits.

The phase-sensitive detector 6 generates an output signal, the amplitude and sign of which is proportional to the phase difference of the signals from the outputs of the amplifier 5 and controlling the mono-phase shifter 7. As the detector 6, a standard phase difference meter of low-frequency signals of type F2-16 or made according to well-known schemes can be used based on integral analog multipliers, for example K140MA1.

The controlled phase shifter 7 shifts the phase of the reference signal from the output of the signal converter 2 by an amount proportional to the voltage from the output of the phase-sensitive detector 6. The phase shifter 7 can be made using known RC-based circuits.

The multiplier 8 multiplies the signals from the outputs of the amplifier 5 and the controlled phase shifter 7, performed a synchronous detection operation. It is made on the basis of integrated circuits such as K140ML1, K525PS1, etc.

An integrator 9 for integrating a signal from the output of a multiplier 8 and can be implemented by known circuits based on integrated operational amplifiers.

Comparator 10 compares the signal from the output of integrator 9 with a predetermined threshold and, when the latter is exceeded, generates a voltage pulse indicating that the controlled zone is crossing. As the comparator 10 can be used almost any integral comparator, for example K521SAZ.

The registrar 11 performs the counting of objects crossing the controlled area. In the proposed device, as standard recorder 11, standard pulse counters can be used or made on the basis of digital integrated circuits with subsequent indication of the result on the board.

The device works as follows.

The clock frequency voltage, for example, a sinusoidal or square wave form, from the generator output, enters the driver 2, which is converted into one of the complex signal types, for example, a signal with linear frequency modulation, discrete frequency modulation, discrete phase modulation and etc. In this case, it is preferable that signals whose base, in general, is equal to the product of the duration per lane, has a maximum value with a minimum signal attenuation in the surrounding aquatic environment. Further, the complex signal is amplified in power and is consistent with the resistance of the monitored section of the medium between transmitting electrodes 12 and 13 using repeater 3. At transmitting electrodes 12 and 13 of sensor A, the complex signal is strictly symmetrical about a zero (midpoint) point, the potential of which is taken as zero level. The receiving electrode 14 is located exactly in the center between the transmitting electrodes 12 and 13 on the same axis with them. In the absence of an object and the described arrangement of the receiving electrode 14, the latter is at a zero equipotential. The signal at the output of amplifier 5 is proportional to the potential difference between the zero point and the point of location of the receiving electrode 14. In the absence of an object, the signal at the output of amplifier 5 is also absent. In the case of the presence of a complex signal at the output of amplifier 5 and the absence of a controlled object by moving the receiving electrode and setting it at zero equipotential, the device is balanced. When an object passes between electrodes 12 and 14 or 13 and 14, the balancing is disturbed and at the output of amplifier 5 a complex signal appears, the amplitude and phase of which are determined by both the characteristics of the object (conductivity, geometrical dimensions, etc.) and which of the transmitting electrodes is closer to the object's trajectory. The phase-sensitive detector 6 evaluates the phase shift between the received and initial complex signals. The controlled phase shifter 7, the multiplier 8 and the integrator 9 together constitute a correlator. In this case, the support delay 1

d 5 0 5 about Q d

35

five

signal and its synchronism is achieved by using a controlled phase shifter 7. Thus, at the output of integrator 9, when the object crosses the controlled area, a signal appears that coincides with the mutual correlation function of the signal from the output of amplifier 5 and a copy of the original complex signal from the output a converter 2 of the signal delayed by a controlled phase shifter 7. Next, the voltage at the output of the integrator 9 is compared with the threshold using a comparator 10 and is recorded by the recorder 11 when the threshold is exceeded. The complexity of a complex signal is chosen to be no less than the time of interaction of the object under control with the electromagnetic field created by the transmitting electrodes 12 and 13.

The use of complex signals and their correlation processing can significantly improve the sensitivity and resolution of the proposed device in comparison with the known ones by improving the signal-to-noise ratio and the effect of temporal compression during correlation processing. In addition, in the proposed device, there is no effect of fluctuations in the conductivity of the environment of the environment on the counting accuracy.

Claims (1)

Invention Formula one . A device for counting motions from objects containing a pulse generator, a repeater, the first output of which is connected to the first input of the sensor, the output of which is connected to the input of the amplifier, an integrator, the output of which is connected to the input of a comparator, and a recorder, counting accuracy, a Phase-sensitive detector, a controlled phase shifter, a multiplier and a pulse shaper are entered into it, the output of the pulse generator is connected to the repeater input and the first input of the pulse generator via ravl emogo phase shifter whose output is connected to the first inputs of multiplier and phase-sensitive detector, whose output is connected to the second input of the phase shifter is controlled emog second output repeater so5 13815566 connected to the second input of the sensor, you-electrodes and the receiving electrode, the amplifier is connected to the second input and second transmitting electrodes, and I will give a phaeosensitive detector and a receiving electrode located on a single multiplier, the output of which is connected to the axis, the receiving electrode is located at the integrator input, the output is in the middle between the first and second the parator is connected to the input of the reg-transmitting electrodes, the first and Rtora.second transmitting electrodes solese2. The device according to claim 1, 1 and 2, respectively, with the first and second So that the sensor with its sensor inputs, the receiving electrode Holds the first and second transmitters connected to the sensor output.