RU2532606C1 - Ultrasonic tomography device - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention can be used to render ultrasonic flaw detection of a three-dimensional article. The ultrasonic tomography device comprises an antenna array with n receiving-transmitting elements, each connected to the output of a corresponding pulse generator and the input of a corresponding amplifier; n analogue-to-digital converters are connected to corresponding inputs of a realisation memory unit, the number of outputs, N, of which is defined by the formula N=n·(n+1)/2. Outputs of the realisation memory unit are connected to corresponding inputs of a computing unit, which is connected to a display through an image memory unit and a storage memory unit. Clock inputs of each pulse generator, realisation memory unit, computing unit and image memory unit are connected to corresponding outputs of a clock unit. A sensitivity temporary adjustment unit is connected to the clock unit and all amplifiers. A multiplicative processing unit is connected to the computing unit and the storage memory unit. The output of each amplifier is connected to a detector, the output of which is connected to an analogue-to-digital converter.

EFFECT: improved definition of the obtained image of the investigated article due to higher resolution.

5 dwg, 1 tbl

Description

The invention relates to the field of analysis using ultrasonic waves of materials or products from metals, ceramics, plastics and can be used in industry for inspection of defects inside parts, for flaw detection of various materials, as well as in medicine for the diagnosis of internal organs.

A device for forming an acoustic image of a controlled object [RU 2246723 C1, IPC7 G01N29 / 04, publ. 02/20/2005], comprising a first generator, the output of which is connected to the input of the first transmitting piezoelectric transducer, a second generator, the output of which is connected to the input of the second transmitting piezoelectric transducer, a first receiving piezoelectric transducer, the output of which is connected to the first receiving device, and a second receiving piezoelectric transducer, the output of which is connected to second receiving device. The outputs of the first and second receiving devices are connected to the first and second inputs of the storage device, the output of which is connected to the input of the electronic computing unit, the first and second outputs of which are connected, respectively, the inputs of the first and second generators. Transmitting piezoelectric transducers are located on the surface of the controlled object. The receiving piezoelectric transducers are arranged to move them along the surface of the controlled object.

The disadvantage of this device is the need for sequential location at various points on the surface of the controlled object of the first and second receiving piezoelectric transducers and the difficulty of comparing each of the M pairs of preliminary images.

A device for ultrasound tomography [RU 2458342 IPC G01N29 / 06 (2006.01), publ. http://www.fips.ru/cdfi/fips.dll?ty=29&docid=2458342&cl=9&path=http://195.208.85.248/Archive/PAT/2012FULL/2012.08.10/DOC/RUNWC1/000/000/ 002/458/342 / document.pdf "\], selected as a prototype, containing an antenna array with n receiving and transmitting elements, each of which is connected to the output of the corresponding pulse generator and the input of the corresponding chain of series-connected amplifier and analog-to-digital converter, the output of each of the n indicated chains is connected to the corresponding input of the implementation memory, the number of outputs of which N is determined by the formula:

N = n · (n + 1) / 2,

the outputs of the implementation memory are connected to the corresponding inputs of the computing unit, which is connected to the storage memory unit and to the display through the image memory. The synchronization inputs of each pulse generator, implementation memory, computing unit and image memory are connected to the corresponding outputs of the synchronizer.

A disadvantage of the known device is the low resolution, determined by the width of the main lobe of the synthesized radiation pattern of the antenna array, consisting of n receiving and transmitting elements, different sensitivity at different depths of the control object, determined by the gain of the amplifier, low signal-to-noise ratio and limited use only ultrasound diagnostics of flat metal structures of a certain thickness.

The objective of the invention is to improve the clarity of visualization of the obtained image of the controlled product by increasing the resolution.

The problem is solved due to the fact that the ultrasound tomography device, as in the prototype, contains an antenna array with n receiving and transmitting elements, each of which is connected to the output of the corresponding pulse generator and the input of the corresponding amplifier, n analog-to-digital converters are connected to the corresponding inputs implementation memory block, the number of outputs of which is N is determined by the formula

N = n · (n + 1) / 2,

the outputs of the implementation memory block are connected to the corresponding inputs of the computing unit associated with the indicator through the image memory block and the storage memory block, while the synchronization inputs of each pulse generator, the implementation memory block, the computing unit and the image memory block are connected to the corresponding outputs of the synchronization block.

According to the invention, the temporal sensitivity adjustment unit is connected to the synchronization unit and all amplifiers, and the multiplicative processing unit is connected to the computing unit and the storage memory unit, and a detector is connected to the output of each amplifier, the output of which is connected to an analog-to-digital converter.

Due to the use of a block of temporary sensitivity adjustment, the attenuation of the ultrasonic signal is compensated as it propagates in the control object and, accordingly, the same sensitivity is maintained at different depths of the control object. The use of the unit of multiplicative processing, in which the signals are coherently multiplied without reflections from the bottom and outer surfaces of the control object, allows narrowing the width of the main lobe of the synthesized antenna array. This improves the clarity of the visualization of the received image of the control object by increasing the resolution at which separate visualization of several adjacent defects is possible, and also increases the signal-to-noise ratio.

In FIG. 1 is a functional diagram of an ultrasound tomography device.

In FIG. 2 is a functional diagram of a multiplier processing unit device.

In FIG. 3 is a functional diagram of a device for a unit for multiplying two numbers.

In FIG. 4 shows the results of visualization of ultrasonic flaw detection of a wheel axis, obtained using: a - a prototype, b - the claimed device, where a and b on the left show a tomographic image of the longitudinal section of the wheel axis in diameter, and on the right - the cross section of the wheel axis.

In FIG. 5 presents the results of visualization of ultrasonic flaw detection of two point defects located at a distance of 2.4 mm from each other, obtained using: a - prototype, b - the proposed device.

Table 1 presents an example of the multiplication of two numbers.

An ultrasound tomography device (Fig. 1) contains an antenna array 1 (AR), which consists of n receiving-transmitting elements 2.1 (PPE1), ..., 2.n (PPEn), each of which is connected to the output of the corresponding pulse generator 3.1 (GI1 ), ..., 3.n (ГИn) and the input of the corresponding chain of series-connected amplifier 4.1 (У1), detector 5.1 (Д1) and analog-to-digital converter 6.1 (ADC1), ..., amplifier 4.n (Уn), detector 5. n (Дn) and analog-to-digital converter 6.n (ADCn).

The output of each analog-to-digital converter 6.1 (ADC1), ..., 6.n (ADCn) is connected to the corresponding input of the implementation memory block 7 (BPR), the number of outputs of which is determined by the formula N = n · (n + 1) / 2. The outputs of the implementation memory block 7 (BPR) are connected to the corresponding inputs of the computing unit 8 (WB) associated with the input of the multiplicative processing unit 9 (BMPO), the output of which is connected to the storage memory block 10 (BNP). Computing unit 8 (WB) is connected to the output of the storage memory block 10 (BNP) and to the input of the image memory block 11 (BPI), which is connected to the indicator 12 (I). The inputs of each pulse generator 3.1 (ГИ1), ..., 3.n (ГИn), an implementation memory block 7 (BPR), a computing block 8 (WB), an image memory block 11 (BPI), and a sensitivity temporal adjustment block 13 (BVRCH) are connected with synchronization unit 14 (BS). The output of the block of temporary adjustment of sensitivity 13 (BVRCH) is connected to each amplifier 4.1 (U1), ..., 4.n (Un). Antenna array 1 (AR) is installed at the monitoring object 15 (OK).

идентичных блоков умножения (фиг. 2), соединенных пирамидально, так что первый уровень содержит n/2 блоков умножения 16.1 (БУ1.1), …, 16.n/2 (БУ1.n/2), входы которых соединены с вычислительным блоком 8 (ВБ). Выходы двух блоков умножения первого уровня 16.1 (БУ1.1) и 16.2 (БУ1.2) связаны с входами одного блока умножения второго уровня 17.1 (БУ2.1). Выходы двух блоков умножения первого уровня 16.3 (БУ1.3) и 16.4 (БУ1.4) связаны с входами одного блока умножения второго уровня 17.2 (БУ2.2). Выходы двух блоков умножения первого уровня 16.(n/2-1) (БУ1.(n/2-1)) и 16.n/2 (БУ1.n/2) связаны с входами одного блока умножения второго уровня 17.n/4 (БУ2.n/4). Выходы двух блоков умножения второго уровня 17.1 (БУ2.1) и 17.2 (БУ2.2) связаны с входами одного блока умножения третьего уровня 18.1 (БУ3.1) и т.д. Выходы блоков умножения третьего уровня 18.1 (БУ3.1) и 18.n/8 (БУ3.n/8) связаны с входом блока умножения n-го уровня 19.1 (БУn/2.1), выход которого является выходом блока мультипликативной обработки 9 (БМПО).Multiplicative Processing Unit 9 (BMPO) consists of

identical multiplication blocks (Fig. 2) connected pyramidally, so that the first level contains n / 2 multiplication blocks 16.1 (BU1.1), ..., 16.n / 2 (BU1.n / 2), the inputs of which are connected to the computing unit 8 (WB). The outputs of two blocks of multiplication of the first level 16.1 (BU1.1) and 16.2 (BU1.2) are connected to the inputs of one block of multiplication of the second level 17.1 (BU2.1). The outputs of two multiplication blocks of the first level 16.3 (BU1.3) and 16.4 (BU1.4) are connected to the inputs of one multiplication block of the second level 17.2 (BU2.2). The outputs of two multiplication units of the first level 16. (n / 2-1) (BU1. (N / 2-1)) and 16.n / 2 (BU1.n / 2) are connected to the inputs of one multiplication unit of the second level 17.n / 4 (BU2.n / 4). The outputs of two blocks of multiplication of the second level 17.1 (BU2.1) and 17.2 (BU2.2) are connected to the inputs of one block of multiplication of the third level 18.1 (BU3.1), etc. The outputs of the third level multiplication blocks 18.1 (BU3.1) and 18.n / 8 (BU3.n / 8) are connected to the input of the n-th level multiplication block 19.1 (BUn / 2.1), the output of which is the output of the multiplicative processing block 9 (BMPO )

The structural diagram of all the multiplication blocks 16.1 (BU1.1), ..., 16.n / 2 (BU1.n / 2), 17.1 (BU2.1), ..., 17.n / 2 (BU2.n / 4), 18.1 (BU3.1), ..., 18.n / 8 (BU3.n / 8), ..., 19.1 (BUn / 2.1) is the same (Fig. 3). For example, in the multiplication block 16.1 (BU1.1), the input of the register of the first number 20 is connected to the computing unit 8 (WB), and the first output of the register of the first number 20 is connected to the input of the first register of the second number 21.1. The second output of the register of the first number 20 is connected to the input of the second register of the second number 21.2, and the nth output of the register of the first number 20 is connected to the input of the nth register of the second number 21.n. The inputs of the registers of the second number 21.1, ..., 21.n are connected to the computing unit 8 (WB). The outputs of the second number registers 21.1, ..., 21.n are connected to the inputs of the adder 22. The output of the adder 22 is the output of each multiplication unit 16.1 (BU1.1), ..., 16.n / 2 (BU1.n / 2), 17.1 (BU2 .1), ..., 17.n / 2 (БУ2.n / 4), 18.1 (БУ3.1), ..., 18.n / 8 (БУ3.n / 8), ..., 19.1 (БУn / 2.1).

Antenna array 1 (AR) is a set of 16 or more receiving and transmitting elements arranged linearly or matrixly, for example OLYMPUS 2L16-A1. Pulse generators 3.1 (ГИ1), ..., 3.n (ГИn) are made on microcircuits having a collector pulse current of at least 2A and an output voltage of 90 V, for example, STHV748. Amplifiers 4.1 (U1), ..., 4.n (Un) are made according to a typical scheme, for example, on AD603 microcircuits. Detectors 5.1 (Д1), ..., 5.n (Дn) are made according to a typical circuit on an operational amplifier, for example, AD603. Analog-to-digital converters 6.1 (ADC1), ...., 6.n (ADCn) are made according to a standard scheme, for example, on ADC9057 microcircuits. The memory block of implementations 7 (BDP), with a volume of at least 64 Kb, is made on standard microcircuits, for example, on microchips IDT72V293. Computing unit 8 (WB) can be performed on a microcontroller, for example ATMEGA64, manufactured by ATMEL. The storage memory block 10 (BNP) and the image memory block 11 (BPI) with a volume of at least 100 MGB can be performed, for example, on memory modules used in personal computers, 1 GB DDR SDRAM PC3200, 400 MHz. Indicator 12 (I) can be performed on a matrix panel or on a personal computer monitor, for example, BENQ G2320HDB. The block of temporary adjustment of sensitivity 13 (BVRCH) can be performed on a digital-to-analog converter, which is part of a microcontroller, for example ATMEGA64, manufactured by ATMEL. The synchronization unit 14 (BS) can be performed on a microcontroller, for example ATMEGA64, manufactured by ATMEL. The register of the first number 20 and the registers of the second number 21.1, ..., 21.n are made on standard microcircuits, for example K1533IR23, the adder 22 can be performed on typical microcircuits for adders, for example K1533IM3.

The device operates as follows.

During the control, for example, of the wheel axis, an antenna array 1 (AR) was placed at its end, containing 32 receiving and transmitting elements 2.1 (PPE1), ..., 2.32 (PPE32) arranged in a matrix. The signal from the synchronization unit 14 (BS), the first pulse generator 3.1 (GI1) supplied an excitation pulse to the first transceiver element 2.1 (PES1) of the antenna array 1 (AR). A probe pulse was emitted into control object 15 (OK). At this point, all the transceiver elements 2.1 (PPE1), ..., 2.32 (PPE32) of the antenna array 1 (AR) begin to receive ultrasonic (ultrasound) vibrations from the monitoring object 15 (OK). At the same time, the temporal sensitivity adjustment block 13 (HIF) starts to change the gain of amplifiers 4.1 (U1), ..., 4.32 (U32), thereby compensating for the attenuation of the ultrasonic wave in the control object 15 (OK). These oscillations, converted into electrical oscillations, are amplified in amplifiers 4.1 (U1), ..., 4.32 (U32), are detected by detectors 5.1 (D1), ..., 5.32 (D32), are digitized in analog-to-digital converters 6.1 (ADC1), ..., 6.32 (ADC32) and are recorded in the memory block of implementations 7 (BPR) independently of each other. These vibrations are recorded in a time interval equal to the propagation time of ultrasonic vibrations from the first transceiver element 2.1 (PES1) of the antenna array 1 (AR) to the farthest visualized point of the monitoring object 15 (OK) and back to the 32nd most distant from it transceiver element of the antenna array 1 (AR).

Next, the pulse generator 3.2 (GI2) connected to the second transceiver element 2.2 (PES2) of the antenna array 1 (AR), by a signal from the synchronization unit 14 (BS), excites the second transceiver element 2.1 (PES2) of the antenna array 1 (AR) ), which sends a probe pulse to the object of control 15 (OK). Again, reception and recording of the received oscillations in the memory block of implementations 7 (BPR) takes place. But the vibrations received by the first transceiver element 2.1 (PES1) of the antenna array 1 (AR) are not recorded in this case, because the implementation of these oscillations according to the reciprocity principle is identical to that which was already adopted by the second transceiver element 2.2 (PES2) of the antenna array 1 (AP) when sending a probe pulse to its first transceiver element 2.1 (PES2) of the antenna array 1 (AP) in the previous sounding-receiving cycle of ultrasonic vibrations.

Then, in the third sensing-receiving cycle of ultrasonic vibrations, everything happens similarly to the above, only the probe pulse to the monitoring object 15 (OK) sends the third transceiver element 2.3 (PES3) of the antenna array 1 (AR), and the oscillations to the memory unit 7 ( BPR) are recorded from 32 transceiver elements of the antenna array 1 (AR).

In the last, 32nd sensing-receiving cycle, the 32nd transceiver element 2.32 (PES32) of the antenna array 1 (AR) acts as a transmitter and receiver of ultrasonic vibrations, i.e. works in combined mode. At the same time, only one implementation of the received oscillations is recorded in the memory block of implementations 7 (BDP).

After performing all these sounding-receiving cycles of ultrasonic vibrations, i.e. after all 32 transmitting and receiving elements of the antenna array 1 (AR) make one sending of a probe pulse, N = 32 · (32 + 1) / 2 = 528 implementations of the received oscillations will be recorded in the memory block of the realizations 7 (BPR).

After all 528 implementations are written to the implementation memory block 7 (BPR), reconstruction of the image of the internal structure of the control object 15 (OK) begins, alternately for each visualized point. The number of visualized points in our example was 6489600 with the following dimensions of the control object: length - 900 mm, diameter - 156 mm. Computing unit 8 (WB) calculated the propagation time of an ultrasonic wave to each visualized point in accordance with the expression:

- координата приемо-передающего элемента антенной решетки 1 (АР), работающего в режиме излучения,Where

- the coordinate of the transceiver element of the antenna array 1 (AR) operating in the radiation mode,

- координата приемо-передающего элемента антенной решетки 1 (АР), работающего в режиме приема;

- the coordinate of the transceiver element of the antenna array 1 (AR), operating in the reception mode;

x, z - coordinates of the rendered point;

C is the propagation velocity of ultrasonic waves in the material of the object of control 15 (OK).

Then, in the block of multiplicative processing 9 (BMPO), the digital codes selected from the memory block of implementations 7 (BPR) were multiplied in accordance with the propagation time from the ith transceiver element of the antenna array 1 (AR) operating in the radiation mode to j- of the receiving and transmitting element of the antenna array 1 (AR) operating in the reception mode through the visualization point with coordinates (x, z) and the result of multiplication was stored in the storage memory unit 10 (BNP).

Multiplicative processing is as follows. At the input of the unit of multiplicative processing 9 (BMPO) from the computational unit 8 (WB), simultaneously, n selected values A0, ..., An of digital codes (n = 32 in our example) are received, which are multiplied in pairs in the blocks of multiplication of the first level 16.1 (BU1.1 ), ..., 16.n / 2 (БУ1.n / 2), the data from the outputs of which are supplied to the inputs of the second-level multiplication blocks 17.1 (БУ2.1), ..., 17.n / 4 (БУ2.n / 4) and multiplied. The data from the outputs of the second level multiplication blocks 17.1 (BU2.1), ..., 17.n / 4 (БУ2.n / 4) are input to the third level multiplication blocks 18.1 (БУ3.1), ..., 18.n / 8 ( BU3.n / 8) and multiplied, etc. The last multiplication is carried out in the n / 2 multiplication block of level 19.1 (BUn / 2.1). The multiplication block, for example 16.1 (BU1.1), works as follows. The first number is written to the register of the first number 20. The second number is received at the inputs of the registers of the second number 21.1, ..., 21.n. Moreover, the second number is received at the input of the first register of the second number 21.1, the second number is received at the input of the second register of the second number 21.2, shifted one digit to the left, the second number is shifted to the input of the second register of the second number 21.3, shifted two digits to the left, etc. d., at the input of the nth register of the second number 21.n the second number is received, shifted by n bits to the left (table 1). Data is recorded in the registers of the second number 21.1, ..., 21.n according to the unit data recorded in the register of the first number 20. If the register of the first number 20 contains zero in any category, then in the corresponding register of the second number 21.1, ..., 21 .n the second number will not be written. Table 1 shows an example of a shift of a five-digit number 11011 at the inputs of the registers of the second number 21.1, ..., 21.n. The register column of the first number shows the value of the first number, in which units are only in the first and fifth digits, so the second number was recorded only in registers 21.1 and 21.5. In the remaining registers of the second number 21.2, 21.3, 21.4 zeros were written. Empty cells in the table are filled with zeros.

Then, the result obtained from the storage memory unit 10 (BNP) was sent to the computing unit 8 (WB), in which the obtained value (number) was assigned a specific color, which was stored in the image memory unit 11 (BPI). Indicator 12 (I) displayed the control result in the form of a color picture.

A comparison of the results of visualization of ultrasonic flaw detection of the wheel axis obtained using the prototype (Fig. 4 a) and the proposed device (Fig. 4 b) shows that when using the inventive device for visualizing ultrasonic flaw detection of a three-dimensional product, the signal-to-noise ratio increased.

A comparison of the results of visualization of ultrasonic inspection of two point defects of the wheel axle located at a distance of 2.4 mm from each other, obtained using the prototype (Fig. 5 a), and the proposed device (Fig. 5 b) shows that when using the prototype it is impossible to distinguish two defects separately, and the proposed device allows them to be seen separately, which indicates an increase in resolution.

Claims (1)

An ultrasound tomography device containing an antenna array with n receiving and transmitting elements, each of which is connected to the output of the corresponding pulse generator and the input of the corresponding amplifier, n analog-to-digital converters are connected to the corresponding inputs of the implementation memory block, the number of outputs of which is N is determined by the formula
N = n · (n + 1) / 2,
the outputs of the implementation memory block are connected to the corresponding inputs of the computing unit associated with the indicator through the image memory block and the storage memory block, while the synchronization inputs of each pulse generator, the implementation memory block, the computing unit and the image memory block are connected to the corresponding outputs of the synchronization block, characterized the fact that the temporary sensitivity adjustment unit is connected to the synchronization unit and all amplifiers, and the multiplicative processing unit is connected to a computing unit and a storage memory unit, while a detector is connected to the output of each amplifier, the output of which is connected to an analog-to-digital converter.

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