SU1582094A1 - Apparatus for checking defects and profiles of surface of articles - Google Patents

Abstract

The invention relates to a non-destructive testing technique and can be used for non-contact monitoring of defects and surface profiles of products. The aim of the invention is to expand the scope. The device implements a light section method for converting the surface geometry of the products into an electrical signal, which is then compared with the signal received from the surface of the reference article. The device contains an illuminator 1, an optoelectronic converter 2, a signal processing unit 3 connected to the output of the optoelectronic converter 2, a driver of 4 coordinate codes, a block of 5 permanent memory devices (ROM) and a sensor 6 of the position of the article under test. In this case, the optoelectronic converter 1 is made on the basis of a photodiode array, the decoding of the elements of which is carried out according to the code signals of the imaging unit 4. The luminance values of the elements of the photodiode array are converted into an electrical signal and compared with the signals recorded in ROM unit 5 by the signal of sensor 6. Depending on from the ratio of these signals, the block 3 generates a signal of the validity or rejection of the product with the help of the logic circuits included in it. 1 il.

Description

The invention relates to non-destructive testing, in particular to optical methods of quality control by the method of reflected radiation.

The aim of the invention is to expand the field of application of the device.

The drawing shows the block diagram of the device.

A device for monitoring defects and surface profiles of products includes an illuminator 1, an opto-electronic converter 2, a signal processing unit 3, a coordinate cowler 4 and a ROM unit 5, a position sensor .16.

The output of the opto-electronic converter 2 is connected to the first input of the signal processing unit 3, the position sensor 6 is connected to the second input of the signal processing unit 3 and to the input of the coordinate code generator 4, the first output of which is connected to the first groups of address inputs of the ROM unit 5 and the first input of the optoelectronic converter 2, the second input of which is combined with the third input of the signal processing unit 3 and connected to the second output of the former 4 coordinate codes, the third output of which is connected to the second group of the inputs of block 5 of the ROM, the first and second outputs of which are connected respectively to the fourth and fifth inputs of the signal processing unit 3, the sixth input of which is connected to the fourth output of the imaging unit 4 coordinate codes, the fifth and sixth outputs of which are connected respectively to the third and fourth optical-to-electronic converter inputs 2.

The optoelectronic converter 2 consists of a lens 7, a photomatrix 8, a decoder 9 whose input is the first input of the optoelectronic converter 2, a switch 10 whose control input is the second, an input of the optoelectronic converter 2, the subtractor 11, the first 12 and 13 second analog memory blocks, the control inputs of which are the third and fourth inputs of the opto-electronic converter 2, respectively, the output of which is the output of the analog memory block 13.

The signal processing unit 3 contains a calculator 14, the first input of which

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is the first input bpock 3, the peak detector 15, analog divider 16, digital-to-analog converter (D / A converter) 17, whose input is the fourth input of signal processing unit 3, first comparator 18, reference voltage source 19, second comparator 20, unit 21 code, the first subtractor 22 codes, the first input of which is the third input of the block

3 signal processing, and the second input of the subtractor 22 is the fifth input of the block 3, the second subtractor 23 codes, D-flip-flops 24 and 25, the R-inputs of which are combined and are the second input of the signal processing unit 3, the RS-trigger 26 and 27, AND circuits 28 and 29, an OR circuit 30, the output of which is the output of block 3.

Shaper 4 codes of coordinates contains a generator 31, AND circuit 32, the first input of which is the first input of shaper 4, shaper 33 of pulses, the first and second outputs of which are respectively the fifth and sixth shaper outputs

4 coordinate codes, the first counter 34, the second counter 35 and the third counter 36, the outputs of which are respectively the second, first and third outputs of the imaging unit 4, and the counting input of the counter 35 is the fourth output of the imaging unit 4 of the coordinate codes.

Block 5 of the ROM contains a block 37 of the intensity ROM, the output of which is the first output of block 5, and block 38 of the coordinate ROM, the output of which is the second output of block 5 of the ROM.

The lighter 1 is optically connected by means of a lens 7 to a photodiode matrix 8, the inputs of which are connected to the outputs of the decoder 9, and the outputs to the analog inputs of the switch 10, the output of which is connected to the summing input of the subtractor 11 and the input of the first block 12 of the analog memory, and the output of the block 12 analog memory is connected to the subtractive input of the subtractor 11, the output of which is connected to the input of the second block 13 of the analog memory.

The subtractive inputs of the subtractor 14 and the comparator 18 are connected to the input of the peak detector 15 and the output of the block 13 of the analog memory, the output of the peak detector 15 is connected to the summing input of the comparator 18, the summing input of the subtractor 14. combined with the first

input analog divider 16 and connected to the output of the DAC 17, the second input of the analog divider 16 is connected to the output of the subtractor 14, the first input of the comparator 20 is connected to the output of the analog divider 16, and its second input to the source 19 of the reference voltage, the output of the comparator 20 is connected to The D input of the D flip-flop 24, the output of the comparator 18 is connected to the first input of the AND 28 circuit, the second input is connected to the output of the device, the input buses of the D / A converter 17 are connected to the output buses; 1, 37 37 ROM of the intensities, the output buses of the block 38 ROM of the coordinates ROM connected to the first group The input of the subtractor is 22 codes, the output buses of which are connected to the first group of inputs of the subtractor of 22 codes, the second group of inputs of which are connected to the setting device 9 1 codes, the output of the subtractor 23 codes connected to the D input of the D-trigger 25, the C inputs D- trigger

24 and 25 are combined with the R-input of the RS-trigger 26 and connected to the output of the circuit And 28, the output of the RS-trigger 26 is connected to the first input of the circuit And 29, the output of which is connected to the S-input of the RS-flip-flop 27. The outputs of the trigger 24,

25 and 27 are connected to the corresponding inputs of the circuit OR 30. The R-inputs of the counters 34-36 of the flip-flops 24, 25, 27 and the first input of the circuit AND 32 are interconnected and connected to the output of the sensor

6 position, the output of the generator 31 is connected to the second input of the circuit AND 32, the output of which is connected to the input of the pulse shaper 33 and the counting input of the counter 34, the Reset input of the peak detector 15, the counting input of the counter 35, the S input of the RS flip-flop 26, the second input of the circuit And 29 are interconnected and connected to the output of the counter 34, the output of the counter 35 is connected to the counting input of the counter 36, the second group of inputs of the subtractor 22 codes are combined with the control inputs of the switch 10 and connected to the output buses of the counter 34, the input buses of the decoder 9, the first groups inputs block 39 of the ROM of the coordinates and block 38 of the ROM of the intensities are interconnected and connected to the output buses of the counter 35, the second groups of inputs of the block 38 of the ROM of the coordinates and block 37 of the ROM of the intensities are combined and connected to the output buses of the counter 36, the control inputs of the blocks 11 and 12

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analog memory connected to the corresponding outputs of the imager 33

pulses.

The basis for converting the geometry of the surface of the products into an electrical signal is the light section method, and the basis for information processing is the method of comparing the electrical signal reflecting the properties of the monitored surface of the product with the signal stored in the ROM received from the surface of the reference product.

The device works as follows.

The controlled article 39, which is oriented upwards with the controlled surface, enters and moves to the control position at a strictly constant speed. The illuminator forms an image of a light strip on the surface of the product, which is projected onto the photosensitive surface of the photomatrix 8 with the help of lens 7, and the position of the illuminated surface areas and their illumination are uniquely related to the geometric dimensions and quality of this surface area of the product.

When the product enters the control zone, the position sensor 6 sets a positive potential at the output, which permits the passage of pulses from the generator 31 through the AND 32 circuit to the counting input of the counter 34 and the control pulse driver 33.

The output code of the counter 34 X varies from 0 to X / wqKC, the overflow pulses of the counter 34 are summed by the counter 35, in which the code Y, is measured from 0 to YMO (KC, and X Mo (COP corresponds to the number of rows, and Y KC to the number of columns photomatrix applied. The overflow pulses of counter 35 are summed by counter 36.

The pulse summing process lasts for the time the part is in the control zone. Before erasing each element, erasing pulses are generated at the erasing input of the photomatrix, which are produced by the control pulse shaper 33. By the same pulses, the zero level of the polled element is recorded in the analog memory block 12.

In subtractor 11, from the current value of the voltage on the element,

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The value of the summing input, the value of the voltage of the zero (initial) level of the element, stored in block 12 of the analog memory and fed to the reading input, is subtracted.

Upon the arrival of read pulses The voltage output of the subtractor 11 is recorded at the control input to the block 13 of the analog memory, and a voltage proportional to the illumination of the elements appears at the output of the block 13 of the analog memory. I The number Z, located in the counter 3J6, corresponds to the number of frames or (| which is the same) the number of controlled sections of the product surface. Codes | s Y and Z are fed to the address input of unit 37 of the ROM of intensities and unit 3J8 of the ROM of coordinates. In block 37 of the ROM of intensities, the stress codes that are input to the DAC are recorded.

7, the output of which produces

with a voltage U0, corresponding to k} ode, and the codes recorded in unit 37 of the ROM of intensities correspond to the voltage that occurs when the reference product is checked at the Z-M section at the Y coordinate.

In the block -38 ROM of the coordinates, codes X are written that correspond to the position Y to the X coordinate for the corresponding Y and Z elements with the maximum illumination when monitoring the reference part. Thus, the image of sections of the reference article is stored in the form of codes in the ROM.

The monitoring process is as follows.

When changing the code X from 0 to

X at the output of the DAC is set M o (kc

The voltage U6 corresponding to the current Y and Z, which is fed to the summing input of the subtractor 14, and the video signal voltage U s is supplied to its subtracting input. In this case, the output of the subtractor 14 is a differential voltage LI; | U0 - II 6C (. Further, the voltage 4U goes to the analog divider 16, to the other input of which the voltage U0 arrives. The output voltage of the divider 4U / U0 carries information about the relative deviation of the intensity of the light flux reflected from the surface of the object, of the intensity of the light flux reflected from the surface of the reference product. The voltage from you

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the analog divider 16 is compared by the comparator 20 with the reference voltage UofJ of the source 19. In the case of a 4U / U0 voltage Uen, the output of the comparator 20 is the voltage of a logical unit, indicating a fault on this control channel.

The current value of the X code and the XQ code recorded in block 38 of the coordinates of the ROM are sent to the 22 code reader, the output of which contains the code 4X | X - X01. In the code reader 23, the JX code is compared with the code arriving from the master 21, and in case X 6 X rvr, a logical unit signal is generated at the output. Thus, a comparison of the difference of the coordinates X for the controlled and reference products with the threshold value A X P0p is made.

Peak detector 15 and comparator 18 serve to highlight the maximum value of a video signal over a period of time during which code X changes its value from 0 to HQ-CX. The video signal U 6 c is fed to the input of the peak detector 15 and to the subtractive input of the comparator 18, the summing input of which receives the voltage from the output of the peak detector 14 U. At the output of the comparator 18, the level of the logical unit is generated when the voltage U g c reaches the maximum value. This indicates the survey element photomatrix with maximum illumination.

After the accumulation cycle of the number X in the counter 34 is completed, the peak detector is zeroed by a pulse of its overflow, after which it is ready for operation. The control results from the outputs of the comparator 20 and the subtractor 23 codes are read into the D-flip-flops 24 and 25, respectively, on the leading edge of the output pulse of the comparator 20 passing through the AND-28 circuit to the C-inputs of the D-flip-flops 24 and 25, in case at the output of the device, a potential of logical zero is established, which corresponds to the product, the surface parameters of which lie within the limits of permissible deviations. If the deviations go beyond the specified norms, then the potential of a logical unit appears at the output of the device, which prohibits the passage of pulses from the output of the compara

torus 20 through an AND circuit 28 and is maintained until the part leaves the control zone.

Triggers 24, 27 and circuit 29 serve to generate a signal of a logical unit at the output of the device if a poll of the elements of one column of the matrix does not reveal a spot of light, which indicates the presence of a defect on the surface of the product.

When a light spot is detected, a positive voltage herrepas appears at the output of the comparator 20, which sets the RS flip-flop 26 to the zero state, and the overflow pulse of the counter 34 sets the RS flip-flop 26 to one state. The S input of the RS-trkgger 27 through AND circuit 29. Otherwise, the RS-flip-flop 26 is not transferred to the zero state and the overflow pulse passes through the AND 30 circuit to the S-input of the RS-flip-flop 27, sets it to the unit state.

The output state of the flip-flops 24, 25, 27 is summed by the OR 30 circuit and arrives at the output of the device.

After the products leave the control zone, a negative voltage drop appears at the output of the position sensor 6, according to which a decision is made on the validity of the product, triggers 24, 25 and 27, counters 34, 35 and 36 are set to zero and the device is ready for control next product.

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Claims (1)

Invention Formula A device for monitoring defects and surface profiles of products containing an illuminator, an opto-electronic converter and a signal processing unit, the first input of which is connected to the output of an opto-electronic converter, characterized in that, in order to expand the field of application of the device, the coordinate code generator is introduced into it , a block of permanent storage devices (ROM) and a position sensor, the output of which is connected to the second input of the signal processing unit and to the input drivers of the coordinate codes, the first output of which It is connected to the first groups of address inputs of the ROM unit and to the first input of the opto-electronic converter, the second input of which is combined with the third input of the signal processing unit and connected to the second output of the coordinate codes generator, the third output is connected to the second group of address inputs of the ROM unit , the first and second outputs of which are connected respectively to the fourth and fifth inputs of the signal processing unit, the sixth input of which is connected to the fourth output of the coordinate codes generator, the fifth and sixth outputs to orogo connected respectively to third and fourth inputs of the opto-electronic transducer.