RU2596907C1 - Device for compensation of error of measurement of ultrasonic locator - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention can be used for compensation of ultrasonic locator error of measurement. This invention consists in fact that device for ultrasonic locator measurement error compensation comprises two independent channels, each of which comprises generator of ultrasonic signals, connected to emitter and series-connected receiver, amplifier, threshold device, time interval generation unit, unit for measuring time interval. To first and second threshold devices reference voltage source is connected, and to first and second time interval measurement units quartz generator is connected. Third time interval measurement unit is connected to first threshold device, to quartz generator and control unit, which is connected to first and second generators, with first and second time interval generation units, with first and second time interval measurement units and indication unit.

EFFECT: technical result is reduced measurement error.

1 cl, 2 dwg

Description

The invention relates to ultrasonic location devices used to measure the depth of wells in the mining industry, shipping and other sectors of the economy.

A device for compensating the error of measurement of an ultrasonic level gauge [RU 75034 U1, IPC G01F 23/28 (2006.01), publ. 07/20/2008], including an ultrasonic signal generator connected to an emitter, a reference voltage source connected to a threshold device, and a receiver, amplifier, threshold device, a time interval generating unit, a control and indication unit, and a second reference voltage source connected in series , a second threshold device and a second time interval generating unit connected to the first threshold device and to a control and indication unit, the second threshold device is connected to the amplifier.

A disadvantage of the known device is the high measurement error due to the deviation of the envelope shape of the received ultrasonic signals from linearly increasing due to propagation in the waveguide.

A device for compensating errors of an ultrasonic borehole depth gauge [RU 2544311 C1, IPC G01N 29/36 (2006.01), publ. 03/20/2015], selected as a prototype, containing an ultrasonic pulse generator connected to the emitter, and a series-connected receiver, amplifier, threshold device, time interval generation unit, time interval measurement unit, and a control and indication unit, the output of which is connected to the generator and the input unit of the formation of the time interval, the reference voltage source connected to the input of the threshold device, a crystal oscillator connected to the unit for measuring time intervals. The second ultrasonic pulse generator is connected to the second emitter. A second receiver, a second amplifier, a second threshold device, a second time interval formation unit and a second time interval measurement unit are connected in series. The reference voltage source is connected to the second input of the second threshold device. The input of the second time interval measurement unit is connected to a crystal oscillator. The output of the second time interval measurement unit is connected to the control and indication unit, the outputs of which are connected to the second generator and the second time interval formation unit.

The disadvantage of this device is the low accuracy of the measurement, due to the inability to determine the response phase of the threshold device, which can vary from 0 to π / 4.

The objective of the invention is to provide a device for compensating the measurement error of an ultrasonic locator, which provides a reduction in measurement error during the waveguide propagation of ultrasonic vibrations.

The proposed device for compensating the measurement error of the ultrasonic locator, as in the prototype, contains two independent channels, each of which contains an ultrasonic signal generator connected to the emitter, and a receiver, amplifier, threshold device, time interval generation unit, time interval measurement unit while the reference voltage source is connected to the first and second threshold device, and to the first and second block of measurement of time intervals ene crystal oscillator.

According to the invention, the third time interval measuring unit is connected to the first threshold device, to a quartz oscillator and a control unit, which is connected to the first and second generator, to the first and second time interval forming unit, to the first and second time interval measuring unit and to an indication unit.

By using the third time interval measurement unit, it is possible to measure the time interval in which the instantaneous amplitude of the received signal of the ultrasonic wave of the first frequency exceeds a threshold level, and based on this, determine the time coordinate of the received signal of the ultrasonic wave of the first frequency. This allows you to compensate for the measurement error of the ultrasonic locator.

In FIG. 1 shows a diagram of a device for compensating the error of measurement of an ultrasonic locator.

In FIG. 2 is a diagram illustrating the operation of the device.

The device for compensating the measurement error of the ultrasonic locator (Fig. 1) contains a control unit 1 (control unit) connected to the first 2 (G1) and second 3 (G2) generators. The output of the first generator 2 (G1) is connected to the first emitter 4 (I1), the output of the second generator 3 (G2) is connected to the second emitter 5 (I2). The first receiver 6 (P1) is connected to the first amplifier 7 (U1), the output of which is connected to the input of the first threshold device 8 (PU1). To the other input of the first threshold device 8 (PU1) is connected a reference voltage source 9 (ION). The output of the first threshold device 8 (PU1) is connected to the input of the first measurement unit of the time interval 10 (BIVI1) and to the input of the first block of the formation of the time interval 11 (BFVI1), to the other input of which the control unit 1 (BU) is connected. The output of the first block of the formation of the time interval 11 (BFVI1) is connected to the input of the second block of measurement of the time interval 12 (BIVI2), the output of which is connected to the control unit 1 (BU). The output of the first measurement unit of the time interval 10 (BIVI1) is connected to the control unit 1 (CU). The second receiver 13 (P2) is connected to a second amplifier 14 (U2), the output of which is connected to the input of the second threshold device 15 (PU2), to the other input of which a reference voltage source 9 (ION) is connected. The output of the second threshold device 15 (PU2) is connected to the input of the second block for the formation of the time interval 16 (BFVI2), to the other input of which the control unit 1 (BU) is connected. The output of the second block for the formation of the time interval 16 (BFVI2) is connected to the input of the third block for measuring the time interval 17 (BIVI3), the output of which is connected to the control unit 1 (BU). A crystal oscillator 18 (KG) is connected to the input of the first measurement unit of the time interval 10 (BIVI1), to the input of the second measurement unit of the time interval 12 and to the input of the third measurement unit of the time interval 17 (BIVI3). The control unit 1 (CU) is connected to the display unit 19 (BI).

The control unit 1 (CU) can be performed on the ATMEGA16 microcontroller. Generators 2 (G1) and 3 (G2) can be made according to the scheme with the discharge of the storage capacitance on KU104G thyristors. Emitters 4 (I1) and 5 (I2), receivers 6 (P1) and 13 (P2) can be made of any piezoceramics, for example, TsTS-19. Amplifiers 7 (U1) and 14 (U2) can be performed on operational amplifiers, for example K544UD2. As threshold devices 8 (PU1) and 15 (PU2), K521CA3 comparators can be used. The blocks for the formation of the time interval 11 (BFVI1) and 16 (BFVI2) can be performed on standard K1554TM2 microcircuits. The time interval measuring units 10 (BIVI1), 12 (BIVI2) and 17 (BIVI3) can be performed on standard microcircuits, for example, K1554IE7. The reference voltage source 9 (ION) is selected as standard REF 192 from ANALOG DEVICES in a standard connection. A standard crystal oscillator 18 (KG) from Geyer Electronic KXO-V97-V1 was used. The display unit 19 (BI) is made on seven-segment indicators of the type DA56-11SRWA.

As an example, consider the determination of the distance of the proposed device. In a 250-cm-long pipe filled with water, emitters 4 (I1) and 5 (I2) were installed, as well as receivers 6 (P1) and 13 (P2). A reflector was mounted at the opposite end of the pipe. The frequency of ultrasonic vibrations of the first emitter 4 (I1) and the first receiver 6 (P1) was 600 kHz, respectively, the wavelength λ ₁ = 2.5 mm, and the oscillation period T ₁ = 1.67 μs. The frequency of ultrasonic vibrations of the second emitter 5 (I2) and the second receiver 13 (P2) was 900 kHz, respectively, the wavelength λ ₂ = 1.67 mm, and the oscillation period T ₂ = 1.11 μs.

The control unit 1 (BU) produced a start signal for the first generator 2 (G1), with the same signal the first block for the formation of the time interval 11 (BFVI1) was set to logical 1. The first generator 2 (G1) excited the first emitter 4 (I1), which emitted ultrasonic signals with a period of T ₁ . The emitted ultrasonic signal propagated through the controlled medium and was received by the first receiver 6 (P1), amplified by the first amplifier 7 (U1) and fed to the input of the first threshold device 8 (PU1). The second input of the first threshold device 8 (PU1) was supplied with voltage U1 from the reference voltage source 9 (ION). As soon as the voltage at the output of the first amplifier 7 (U1) exceeded the voltage U1, the output of the first threshold device 8 (PU1) switched to the logical 1 state, which reset the first block of the formation of time interval 11 (BFVI1) to the logical 0 state (point t ₁ in FIG. . 2). Thus, at the output of the first block of the formation of the time interval 11 (BFVI1), a signal was obtained whose duration is equal to time:

Δt ₁ = t ₁ -t ₀ ,

where t ₀ is the initial time of radiation of the ultrasonic signal of the first frequency.

This signal was received in the second block of measurement of the time interval 12 (BIVI2), the signal from the quartz generator 18 (KG) was received at the second input of the second block of measurement of the time interval 12 (BIVI2). Data on the duration of the second time interval was received in the control unit 1 (CU). In addition, the logical 1 at the output of the first threshold device 8 (PU1) allowed the operation of the first measurement unit of the time interval 10 (BIVI1). The second input of the first unit of measurement of the time interval 10 (BIVI1) received a signal from a quartz generator 18 (KG).

As soon as the voltage at the output of the first amplifier 7 (U1) became less than the voltage U1, the output of the first threshold device 8 (PU1) switched to the logical 0 state, which stopped the operation of the first measurement unit of the time interval 10 (BIVI1) (point t ₃ in Fig. 2 ) Data from the first measurement unit of the time interval 10 (BIVI1) was received in the control unit 1 (BU), which calculated the correction value:

,

,

where T ₁ - the period of oscillation of the ultrasonic signal of the first frequency,

t is the time interval in which the instantaneous value of the amplitude of the received ultrasonic signal of the first frequency exceeds the threshold level.

Then the control unit 1 (BU) generated a start signal for the second generator 3 (G2), with the same signal the second block for the formation of the time interval 16 (BFVI2) was set to logical 1. The second generator 3 (G2) excited the second emitter 5 (I2), which emitted ultrasonic signals with a period of T ₂ . The emitted ultrasonic signal propagated through the same controlled medium and was received by the second receiver 13 (P2), amplified by the second amplifier 14 (U2) and entered the input of the second threshold device 15 (PU2). The second input of the second threshold device 15 (PU2) was supplied with voltage U1 from the reference voltage source 9 (ION). As soon as the voltage at the output of the second amplifier 14 (U2) exceeded the voltage U1, the output of the second threshold device 15 (PU2) switched to the logical 1 state, which reset the second block of the formation of the time interval 16 (BFVI2) to the logical 0 state (point t ₂ in FIG. . 2).

Thus, at the output of the second block for the formation of time interval 16 (BFVI2), a signal was obtained whose duration is equal to time:

Δt ₂ = t ₂ -t ₀ ,

This signal was received in the third block for measuring the time interval 17 (BIVI3), the signal from the quartz generator 18 (KG) was received at the second input of the third block for measuring the time interval 17 (BIVI3). Data on the duration of the third time interval was received in the control unit 1 (CU).

The time intervals between the emitted and received ultrasonic signals, measured by time interval measurement units 12 (BIVI2) and 17 (BIVI3), had the durations:

Δt ₁ = 328.7 μs,

Δt ₂ = 326.8 μs.

The control unit 1 (BU) made the first correction of these time intervals in accordance with the expression:

where T ₁ - the period of oscillation of the ultrasonic wave of the first frequency,

T ₂ - the period of oscillation of the ultrasonic wave of the second frequency,

i is the correction number,

- первый скорректированный временной интервал,

- the first adjusted time interval,

- второй скорректированный временной интервал.

- the second adjusted time interval.

After that, the control unit 1 (BU) has compared the results of the correction:

After correction according to formulas (1) and (2), we obtained the following set of values:

.

.

As a result, a value exceeding a quarter of the period of ultrasonic vibrations was obtained.

The control unit 1 (BU) carried out the second correction of these time intervals:

After the second correction (i = 2), a value exceeding a quarter of the period of ultrasonic vibrations was obtained.

The control unit 1 (BU) carried out the third correction of these time intervals:

.

.

After the third correction (i = 3), we obtained the time difference of the first and second interval, which is less than a quarter of the period of ultrasonic signals of the first frequency.

The time interval in which the instantaneous value of the amplitude of the received ultrasonic signal of the first frequency exceeds the threshold level measured by the measuring unit of the time interval 11 (BIVI1), had the duration:

t = 0.4 μs.

Then the control unit and display 1 (BU) determined the duration of the corrective time interval in accordance with the expression:

,

,

After that, the control unit 1 (BU) determined the time coordinate of the beginning of the received signal of the ultrasonic wave of the first frequency:

Using this time coordinate, the control unit 1 (BU) determined the distance to the reflector h and transmitted the data to the display unit 19 (BI) for display.

where C is the speed of propagation of ultrasound in water.

The error in measuring the level Δh was:

Δh = 250-250.11 = 0.11 mm.

Thus, it was experimentally established that the error in measuring the distance to the reflector was λ / 22.

Claims (1)

An ultrasonic locator measurement error compensation device comprising two independent channels, each of which contains an ultrasonic signal generator connected to an emitter, and a series-connected receiver, amplifier, threshold device, time interval generation unit, time interval measurement unit, while to the first and second a reference voltage source is connected to the threshold device, and a crystal oscillator is connected to the first and second time interval measurement unit, the fact that the third time interval measurement unit is connected to the first threshold device, to a quartz oscillator and a control unit that is connected to the first and second generator, to the first and second time interval formation unit, to the first and second time interval measurement unit, and to the unit indication.

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