CN102095374A - Method and device for measuring displacement along optical axis direction by using peaks and valleys of three primary colors as characteristics - Google Patents

Abstract

The invention discloses a method and a device for measuring displacement along an optical axis direction by using peaks and valleys of three primary colors as characteristics. The device consists of a common computer and a camera thereof, a step motor and an interface circuit thereof and a camera axial displacement device. The camera is arranged on the axial displacement device formed by using the high-precision micro displacement step motor as a core, the step motor is connected to the RS232C interface of the computer through the interface circuit of the step motor, and the computer is configured with a program for shooting with the camera and measuring the axial displacement according to the peak and valley data of the three primary colors. The method comprises the following steps of: automatically analyzing and selecting an optimal observation region by computing self-associated coefficients; controlling the rotation of the step motor through the RS232C interface of the computer, and operating the camera to advance or retreat; and analyzing and measuring the number of peaks and valleys of the three primary colors of an image frame along two coordinate axis directions, and determining the position with highest number as an optimal imaging and focusing position so as to acquire the axial relative displacement. The measurement method is novel, and can adapt to the environmental illumination change of a certain degree.

Description

With the three primary colours peak valley is method and the device of pattern measurement along the displacement of optical axis direction

Technical field

The invention belongs to the digital picture field of measuring technique, the camera Measuring Object that particularly uses a computer is along the method and the device thereof of the micro-displacement of its optic axis direction generation.

Background technology

The technology of the spatial information of relevant detection object has been analyzed in the application for a patent for invention of submitting to " is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours contrast " recently, and the photosensor arrays that has proposed a kind of camera that uses a computer is surveyed along the method for the micro-displacement of optic axis direction generation.In fact, the information that photosensor arrays reflected of computing machine camera is much abundant than picture limit detector or semiconductor position sensor (PSD), gives full play to its function, is worth research.

Summary of the invention

The invention provides a kind of is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours peak valley, it utilizes the computing machine camera, can take place in the environment of certain variation at illuminating position, Measuring Object is along the micro-displacement vector that optical axis direction took place of camera.

The technical solution adopted for the present invention to solve the technical problems is: computing machine camera of computer configuration that a Daepori is logical, it is on the axial displacement device formed of core by the high-precision micro displacement stepper motor that this camera is installed in one, this stepper motor is connected to the RS232C interface of described computing machine by the stepper motor interface circuit, described computer configuration has camera to take and according to three primary colours peak valley DATA REASONING axial displacement program, it is the method for the pattern measurement axial displacement of picture frame that this program has embodied with the three primary colours peak valley, comprising:

Step 1, with the form of bitmap (M * N, M, N ∈ positive integer), take the image of a frame testee, as the reference frame; First locations of pixels with this frame pel array upper left corner is an initial point, is the x direction of principal axis with to the right direction, and vertical downward direction is the y direction of principal axis, and the unit of the coordinate system of getting is the size of a pixel; Choose a zone at the middle section of described pel array, size is m ₀* n ₀, m ₀, n ₀The ∈ positive integer is referred to as view window, and the horizontal direction of the described pel array of its distance and the edge pixel of vertical direction respectively have h and v pixel, promptly have: m ₀+ 2h=M, n ₀+ 2v=N, h, v ∈ positive integer;

Step 2, for the pel array of above-mentioned reference frame, by pixel column, by the edge direction data of pixel column derivation along X-direction and Y direction, and with the binary numeral 001 of 3bit, 010 and 100 wherein positive limit, marginal and the 3rd class limits of expression respectively, so constituted corresponding described reference frame pel array about X-direction with about two frame edge direction data { reference of Y direction _x(x, y) } and { reference _y(x, y) }, wherein, subscript x or y represent the direction of the coordinate axis on institute edge respectively, all pixels in the change in coordinate axis direction view window that symbol " { } " expression is indicated along function subscript wherein (x, these data are preserved in a set of the edge direction data of y) locating;

Step 3, for above-mentioned two frame edge direction data, calculate the auto correlation matching factor of view window interior pixel array in the described reference frame respectively:

$\mathrm{auto}\_{\mathrm{correlation}}_x(a,b)=\underset{y=v+1}{\overset{v+1+\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="H2009101916264E00011.png,H2009101916264E00012.png"\; state="\{\{state\}\}">n</figure-callout>}0}{\mathrm{\&Sigma;}}}\underset{x=h+1}{\overset{h+1+m0}{\mathrm{\&Sigma;}}}[{\mathrm{reference}}_x(x,y)\&CenterDot;{\mathrm{reference}}_x(x+a,y+b)]$

$\mathrm{auto}\_{\mathrm{correlation}}_y(a,b)=[{\mathrm{reference}}_y(x,y)\&CenterDot;{\mathrm{reference}}_y(x+a,y+b)]$

In the formula, sign of operation is represented binary logic and computing, its operation result or be logical zero or for logical one, the pairing numerical value of value of logical operation function is wherein got in sign of operation " [] " expression, or is numerical value 0, or is numerical value 1, parametric variable a, the combination of b has determined the scale of associated match operator array, if get 3 * 3 associated match operator array: a=-1,0,1, b=-1,0,1, therefore, each will produce 9 auto correlation coefficient auto_correlation along each change in coordinate axis direction _x(a, b) and auto_correlation _y(a, b);

Step 4, according to the auto correlation matching factor of above-mentioned two frame edge direction data correspondences, search for respectively and under present body surface situation and illuminating position, can carry out matching ratio optimal viewing window pel array:

m _x＝m ₀±step，n _x＝n ₀±step，2h＝M-m _x，2v＝N-n _x

And m _y=m ₀± step, n _y=n ₀± step, 2h=M-m _y, 2v=N-n _y,

In the formula, subscript x, y represent respectively its value corresponding along X-direction and Y direction, step is the stepped parameter in the search procedure, the unlike signs of its front is determined by the direction of search; Get in this two class value big person and measure the scale of used view window array: m * n for this;

Step 5, for the pel array of above-mentioned reference frame, data according to its redness, green and blue component, respectively line by line, derive along the redness of X-axis and Y direction, green and edge direction data blueness by row, one has 3 * 2=6 frame edge direction data;

According to the edge direction data of above-mentioned three kinds of primary colours, derive respectively along the limit reflection condition of three kinds of primary colours of X-axis and Y direction, have 3 * 2=6 frame limit reflection condition; For view window zone wherein, use the number of their pairing peaks of accumulator count, paddy: N respectively _{RX axle peak}, N _{RX axle paddy}, N _{RY axle peak}And N _{RY axle paddy}, N _{GX axle peak}, N _{GX axle paddy}, N _{GY axle peak}And N _{GY axle paddy}, N _{BX axle peak}, N _{BX axle paddy}, N _{BY axle peak}And N _{BY axle paddy}, wherein, N (umber) represents number, R, G, B represent the red, green and blue look respectively; Add up above-mentioned totalizer count results and preserve it, be expressed as: N (i, j=0, forw=0, back=0), wherein, i=1,2,3...... represents the sequential counting of captured reference frame, also be the counting of measuring, j=0,1,2,3 ..., represent the counting of the sampling frame taken in the i time measuring process, variable forw (=0,1,2 ...) and back (=0,1,2 ...) represent stepper motor generation clockwise rotation described in the i time measurement and the pairing step-by-step impulse counting of anticlockwise rotation respectively, before this measures beginning, have: i=1, j=0, forw=0, back=0;

Step 6, measurement beginning: described computing machine is exported forw=1 digital pulse signal to described stepper motor interface circuit by an output control line FORWARD of its RS232C interface, control this stepper motor clockwise and rotate a step, then, take j=1 frame sample framing bit figure;

For the pel array of above-mentioned sampling frame,, respectively line by line, derive along the redness of X-axis and Y direction, green and edge direction data blueness, have 3 * 2=6 frame edge direction data by row according to the data of its redness, green and blue component;

According to the edge direction data of above-mentioned three kinds of primary colours, derive respectively along the limit reflection condition of three kinds of primary colours of X-axis and Y direction, have 3 * 2=6 frame limit reflection condition; For view window zone wherein, use the number of their pairing peaks of accumulator count, paddy: N respectively _{RX axle peak}, N _{RX axle paddy}, N _{RY axle peak}And N _{RY axle paddy}, N _{GX axle peak}, N _{GX axle paddy}, N _{GY axle peak}And N _{GY axle paddy}, N _{BX axle peak}, NB _{X-axis paddy}, N _{BY axle peak}And N _{BY axle paddy}Add up above-mentioned totalizer count results and preserve it, be expressed as: N (i, j=1, forw=1, back=0);

Step 7, if: N (i, j=1, forw=1, back=0) 〉=N (i, j=0, forw=0, back=0), described computing machine is exported forw (=2,3 by an output control line FORWARD of its RS232C interface, ...) individual digital pulse signal is to described stepper motor interface circuit, it is progressive to control this stepper motor clockwise rotation, and each one step of clockwise rotation all takes and analyzes and respectively takes a sample before and after the comparison in the frame in the view window along all peaks of three kinds of primary colours of X-axis and Y direction and the number sum N (i of paddy, j=forw-1, forw-1, back=0) and N (i, j=forw, forw, back=0), preserve it, should have in this process: N (i, j=forw, forw, back=0) 〉=N (i, j=forw-1, forw-1, back=0), up to satisfying: N (i, j=forw, forw, back=0)＜N (i, j=forw-1, forw-1, back=0), at this moment, record (forw) _MAX=forw, simultaneously, described computing machine arrives described stepper motor interface circuit by another root output control line BACKWARD digital pulse signal of output (back=1) of its RS232C interface, control anticlockwise one step of rotation of this stepper motor, at this moment, this measures the preceding initial position of beginning relatively, and the camera of this device promptly is in the best object image-forming focal position in this measurement: FocusP=(forw) _MAX-back=(forw) _MAX-1, its result calculated is more than or equal to 0, the sense of rotation of representing described stepper motor is clockwise, in the sampling frame view window of this focal position correspondence along all peaks of three kinds of primary colours of X-axis and Y direction and the number sum of paddy is: N (i, j=(forw) _MAX-1, forw=(forw) _MAX-1, back=0), the tale result of the sampling frame of taking in the measuring process is: j=(forw) _MAX+ back=(forw) _MAX+ 1;

If: N (i, j=1, forw=1, back=0)＜N (i, j=0, forw=0, back=0), described computing machine is exported back=1 digital pulse signal to described stepper motor interface circuit by an output control line BACKWARD of its RS232C interface, control the anticlockwise rotation backward of this stepper motor, promptly get back to the initial position of this measurement, then, described computing machine continues output back (=2 by the output control line BACKWARD of its RS232C interface, 3 ...) individual digital pulse signal is to described stepper motor interface circuit, controls the further anticlockwise rotation of this stepper motor, in this process, one step of each anticlockwise rotation all takes and analyzes and respectively takes a sample before and after the comparison in the frame view window along all peaks of three kinds of primary colours of X-axis and Y direction and number sum N (i, j=back+1, the forw=1 of paddy, back) and N (i, j=back, forw=1, back=back-1), should have: N (i, j=back+1, forw=1, back=back) 〉=N (i, j=back, forw=1 back=back-1), preserves it, so continue, up to satisfying: N (i, j=back+1, forw=1, back)＜N (i, j=back, forw=1, back-1), at this moment, record: (back) _MAX=back, simultaneously, described computing machine arrives described stepper motor interface circuit by another root output control line FORWARD digital pulse signal of output (forw=2) of its RS232C interface, control this stepper motor clockwise and rotate a step, at this moment, this measures the preceding initial position of beginning relatively, and the camera of this device promptly is in the best object image-forming focal position in this measurement: FocusP=forw-(back) _MAX=2-(back) _MAXIts result calculated is a negative value, the sense of rotation of representing described stepper motor is anticlockwise, in the sampling frame view window of this focal position correspondence along all peaks of three kinds of primary colours of X-axis and Y direction and the number sum of paddy is: N (i, j=((back) _MAX-1)+1=(back) _MAX, forw=1, back=(back) _MAXThe tale result of the sampling frame of-1), taking in the measuring process is: j=forw+ (back) _MAX=2+ (back) _MAX

Integrate, this measures the preceding initial position of beginning relatively, and the object that this measurement is obtained along the displacement of the optic axis direction generation of described camera is: Δ z (i)=forw-back,

The value of counter forw and back is count results last in this measuring process in the aforementioned calculation formula, result of calculation has the symbol of plus or minus, the displacement that taken place of the expression direction of advancing or retreating respectively along optic axis, corresponding to the sense of rotation of described stepper motor (promptly clockwise or anticlockwise), specifically determine by the arrangement of the axial displacement device of stepper motor;

Total displacement is: Δ Z ₀(i)=Δ Z ₀(i-1)+Δ z (i)

Wherein, Δ Z ₀(i-1) measure the axial displacement of accumulation before for this;

Step 8, prepare surveying work next time: measure time counter i=i+1, the number sum of getting all peaks of measuring the interior three kinds of primary colours along X-axis and Y direction of the corresponding object image-forming frame of the best object image-forming focal position view window of determining for the i time and paddy is as new witness mark value:

N (i, j=0, forw=0, back=0)=N (i, j=(forw) _MAX-1, forw=(forw) _MAX-1, back=0), or N (i, j=0, forw=0, back=0)=

N(i，j＝((back) _MAX-1)+1＝(back) _MAX，forw＝1，back＝(back) _MAX-1)；

Step 9, jump to step 6, continue to measure;

In the actual measurement process,, can obtain direct measurement result by measuring calibration.

Above-mentioned camera is taken and according to the definition of edge direction data described in the step of three primary colours peak valley DATA REASONING axial displacement program is:

In the pel array, along X-axis or along Y direction, if the light intensity value of a pixel is than the also little error margin value error of second corresponding light intensity value of pixel of its back, if promptly

I (X, Y)＜I (X+2, Y)-error or I (X, Y)＜I (X, Y+2)-error

Then define and have this axial positive limit, an edge between these two pixels; If the light intensity value of a pixel is than the also big error margin value error of second corresponding light intensity value of pixel of its back, if promptly

I (X, Y)＞I (X+2, Y)+error or I (X, Y)＞I (X, Y+2)+error

Then define between these two pixels and to have an edge this is axial marginal; So the limit that obtains is positioned at this pixel first locations of pixels afterwards, also promptly is positioned on that pixel in the centre position that participates in two pixels relatively; If second corresponding light intensity value of pixel of certain light intensity value of a pixel and its back is approaching, its value differs and is no more than an error margin value error, if promptly

I(X+2，Y)-error≤I(X，Y)≤I(X+2，Y)+error

Or I (X, Y+2)-error≤I (X, Y)≤I (X, Y+2)+error,

Then think not have corresponding " limit " along this direction of principal axis between these two pixels, or be referred to as the 3rd class limit;

Along some change in coordinate axis direction, all positive limit of corresponding pixel column or pixel column, marginal and the 3rd class limit form this row maybe these row along the edge direction data of this change in coordinate axis direction; Error margin value in the above-listed formula can be predisposed to a little numerical value, for example: error=10 according to concrete light conditions; There are not the edge direction data in four limits in the pel array and the location of pixels on the angle.

Above-mentioned camera is taken and is comprised according to the method for searching for optimal viewing window pel array described in the step of three primary colours peak valley DATA REASONING axial displacement program:

For the view window of described pel array and k * k (k ∈ positive integer) associated match operator array (a b), can produce k * k auto correlation matching factor along certain change in coordinate axis direction, by following inequality these auto correlation matching factors relatively:

auto_correlation(a，b)≥auto_correlation(0，0)×similarity

In the formula, similarity has described the similarity degree of the pel array of view window and its contiguous identical scale, for example gets similarity=60%, can set in advance, and also can debug and selects according to the quality on light conditions and measured object surface;

If the auto correlation coefficient that satisfies above-mentioned inequality more than k * k * 1/3, needs to enlarge the capable and step row of each step of scope of view window: make m=m ₀+ step, n=n ₀+ step, recomputate the auto correlation coefficient of new view window, and carry out above-mentioned comparison, up to the no more than k * k of auto correlation matching factor that satisfies above-mentioned inequality * 1/3, at this moment, 2h=M-m, 2v=N-n, wherein, step is a stepped parameter, initial value is 1, needs the scale of expansion view window just to increase by 1 at every turn; If exceed predetermined scope in the frame, also do not find suitable view window, think that then the quality of this this part reflecting surface of object is unsuitable for the surveying work of this device, and provide the prompting warning;

If satisfy the no more than k * k of auto correlation matching factor of above-mentioned inequality * 1/3, the architectural feature on surface that subject is described is enough meticulous, value between the neighborhood pixels can be distinguished, can further attempt dwindling the capable and step row of each step of scope of view window, to reduce amount of calculation: make m=m ₀-step, n=n ₀-step recomputates the auto correlation coefficient of view window, and carries out above-mentioned comparison, the parameter s of going forward one by one tep is each to increase by 1, the number that satisfies the auto correlation coefficient of above-mentioned inequality up to selected view window zone is not less than k * k * 1/3, at this moment, thinks to have searched optimal viewing window pel array.

Above-mentioned camera is taken and according to the definition of edge direction data red, green or blue described in the step of three primary colours peak valley DATA REASONING axial displacement program is:

Component data according to one of red in the pel array, green or these three kinds of primary colours of blueness, along X-axis or along Y direction, if certain three primary colours component value of a pixel is than the also little error margin value error of the corresponding three primary colours component value of second pixel of its back, if promptly

I (X, Y) _Red＜I _Red(X+2, Y)-error or I (X, Y) _Red＜I (X, Y+2) _Red-error

I (X, Y) _Green＜I _Green(X+2, Y)-error or I (X, Y) _Green＜I (X, Y+2) _Green-error

I (X, Y) _Blue＜I _Blue(X+2, Y)-error or I (X, Y) _Blue＜I (X, Y+2) _Blue-error

Then define and have a positive limit redness, green or blue between these two pixels; If certain three primary colours component value of a pixel is than the also big error margin value error of the corresponding three primary colours component value of second pixel of its back, if promptly

I (X, Y) _Red＞I _Red(X+2, Y)+error or I (X, Y) _Red＞I (X, Y+2) _Red+ error

I (X, Y) _Green＞I _Green(X+2, Y)+error or I (X, Y) _Green＞I (X, Y+2) _Green+ error

I (X, Y) _Blue＞I _Blue(X+2, Y)+error or I (X, Y) _Blue＞I (X, Y+2) _Blue+ error

Then define and have the marginal of a redness, green or blueness between these two pixels; So the limit that obtains is positioned at this pixel first locations of pixels afterwards, also promptly is positioned on that pixel in the centre position that participates in two pixels relatively; If the corresponding three primary colours component value of second pixel of certain three primary colours component value of a pixel and its back is approaching, its RGB component value differs and is no more than an error margin value error, if promptly

I (X+2, Y) _Red-error≤I (X, Y) _Red≤ I (X+2, Y) _Red+ error

Or I (X, Y+2) _Red-error≤I (X, Y) _Red≤ I (X, Y+2) _Red+ error;

I (X+2, Y) _Green-error≤I (X, Y) _Green≤ I (X+2, Y) _Green+ error

Or I (X, Y+2) _Green-error≤I (X, Y) _Green≤ I (X, Y+2) _Green+ error;

I (X+2, Y) _Blue-error≤I (X, Y) _Blue≤ I (X+2, Y) _Blue+ error

Or I (X, Y+2) _Blue-error≤I (X, Y) _Blue≤ I (X, Y+2) _Blue+ error;

Then think not have " limit " of this color wavelength correspondence between these two pixels, or be referred to as the limit of the 3rd this color of class; Along some change in coordinate axis direction, the edge direction data of this direction redness are formed on the positive limit of all redness and red limit marginal and the 3rd class redness, the edge direction data of this direction green are formed on the positive limit of all greens and green limit marginal and the 3rd class green, and the edge direction data of this direction blueness are formed on the positive limit of all bluenesss and blue limit marginal and the 3rd class blueness; Error margin value in the above-mentioned formula can be predisposed to a little numerical value, for example: error=10 according to concrete light conditions; There are not the edge direction data in four limits in the pel array and the location of pixels on the angle.

Above-mentioned camera take and according to described in the step of three primary colours peak valley DATA REASONING axial displacement program along the limit reflection condition of three kinds of primary colours of X-axis and Y direction, it is defined as:

According to redness, green or the blue edge direction data of selected observation row with the pixel of observation row, along X-axis or along Y direction, if continuous two or more than the positive limit of certain primary colours of two, or continuous two or more than and then these primary colours marginal after the 3rd class limit of these primary colours of two, be referred to as the first kind limit reflection condition of these primary colours, promptly think the peak that has these primary colours in this position; If continuous two or marginal more than certain primary colours of two, or continuous two or more than the and then positive limit of these primary colours after the 3rd class limit of these primary colours of two, be referred to as the second class limit reflection condition of these primary colours, promptly think the paddy that has these primary colours in this position; Along X-axis or along Y direction, its all peak of one of three kinds of primary colours and these primary colours of paddy composition diagram picture frame are along the limit reflection condition of this change in coordinate axis direction.

Described camera axial displacement device comprises: described camera is installed on the worktable, this worktable and a long tap turning axle are with the tap socket, this tap turning axle is installed on the big worktable by two bracing frames, and, it and these two bracing frames all are the mode sockets with rotating shaft, can rotate at the socket place with bracing frame but forward or backward displacement does not take place; A fixing gear is arranged, the mutual interlock of gear above the rotating shaft of it and stepper motor on the described tap turning axle.Described stepper motor also is installed on the described big worktable, and it is connected to the RS232C interface of computer system by the stepper motor interface circuit.

Advantage of the present invention is, the information that it has utilized existing camera to take more fully, with about the peak of pixel three primary colours and paddy data as the feature of testee picture frame, by calculating the auto correlation coefficient, analyze and choose the optimal viewing zone automatically; By counting the number of characteristics of image in this viewing area, the degree of judgment object imaging and focusing, and then the micro-displacement that taken place in camera optic axis direction of Measuring Object; This measuring method advanced person, the ambient lighting that can adapt to a certain degree changes.

Description of drawings

Further specify patent of the present invention below in conjunction with accompanying drawing.

Fig. 1 is computing machine of the present invention and camera measuring system block scheme thereof.

Fig. 2 be of the present invention be the camera axial displacement device block scheme that core is formed by the high-precision micro displacement stepper motor.

Fig. 3 is that optical imagery of the present invention focuses on the process synoptic diagram.

Fig. 4 is that the photoelectric sensor chip carries out the pel array and the view window area schematic thereof that produce after the opto-electronic conversion.

Fig. 5 is the synoptic diagram of a traveling optical signal and digitized signal, edge direction data and limit reflection condition.

Among Fig. 1,1. computing machine camera, 2. optical lens, 3. photoelectric sensor chip, 4.USB interface, 5. computer system, 6.USB interface, 7.CPU, 8.RS232C interface, 9. display card and display, 10. internal memory and hard disk, 11. keyboards and mouse, 12. operating system, 13. webcam driver program, 14. cameras are taken and according to three primary colours peak valley DATA REASONING axial displacement program, 15. light fixture.

Among Fig. 2,30. the worktable of stepper motor and camera, 31. bracing frame, 32. bracing frame, the worktable of 33. cameras (1), 34. tap turning axles, 341. the gear on the tap turning axle (34), 40. stepper motor, the turning axle of 41. stepper motors (40), the gear on the turning axle (41) of 42. stepper motors (40).

Among Fig. 3,90.-96. object (circle hot spot) synoptic diagram of different position imagings on optical axis, 97. optic axises.

Among Fig. 5,21. 1 traveling optical signals, 22. with the corresponding digitized signal of light signal (21), 23. edge direction data corresponding, the limit reflection condition of 24. corresponding sides directional datas (23) with digitized signal (22).

Embodiment

Patent of the present invention comprises two parts: computing machine shown in Figure 1 and camera measuring system thereof, shown in Figure 2 be the camera axial displacement device that core is formed by the high-precision micro displacement stepper motor.

Go up the webcam driver program (13) of operation the placing in computer system (5), be connected camera (1) with (6) to computing machine (5) by USB interface (4).Then, allow camera focal imaging object being measured.

The preferential measurement environment of selecting is indoor, and the surround lighting radiation variation is little, helps measuring.Select the basic demand of measurement environment to be, allow illuminating position that certain variation takes place in measuring process, but do not allow this variation to influence the light and shade contrast of object being measured imaging significantly.Select for use light fixture (15) to help enforcement of the present invention.For example adopt irreflexive even lighting system, or its intensity of light fixture can be better than the influence of environment parasitic light.The material of object being measured preferably has more careful surface reflection feature, also can select for use this type of material to make target, avoids or overcomes smooth reflecting surface material.

As shown in Figure 2, camera (1) is installed on the worktable (33), moves with worktable, and this worktable (33) and a long tap turning axle (34) are with the tap socket.Tap turning axle (34) is installed on the big worktable (30) by bracing frame (31) and (32), and, tap turning axle (34) and bracing frame (31) and (32) all are the mode sockets with rotating shaft, and tap turning axle (34) can rotate at the socket place with bracing frame (31) and (32) but forward or backward displacement does not take place.A fixing gear (341) is arranged on the tap turning axle (34), the interlock mutually of gear (42) above the rotating shaft (41) of it and stepper motor (40), when the rotating shaft (41) of stepper motor (40) is rotated, rotation meeting driven gear (341) rotation of gear (42), and then drive tap turning axle (34) rotation, impel camera (1) and worktable (33) thereof to be moved forward or backward together.Stepper motor (40) also is installed on the big worktable (30).

Choose two output signal lines of RS232C interface (8) lining of computer system (5), FORWARD as shown in the figure and BACKWARD, receive a stepper motor interface circuit (43) with a ground wire GROUND, carry out power amplification at this, then, be connected to stepper motor (40), control step motor (40) is done clockwise rotation or anticlockwise rotation.

The property relationship of stepper motor (40) is to the measuring accuracy of patent of the present invention, should select that step-wise displacement is meticulous, precision is high, the motor of working stability for use,

The operation camera is taken and according to three primary colours peak valley DATA REASONING axial displacement program (14), in real time Displacement Measurement.Concrete steps see that " summary of the invention " describe, and are as follows with regard to its general condensed summary below.

Whether clear the principle of patent measurement optical shaft orientation micrometric displacement of the present invention and method be based on optical imagery focusing, and as shown in Figure 3, its judgment criterion is: when focusing on clearly, picture frame view window zone has the maximum characteristics of image of number--limit reflection condition.Relevant photoelectric sensor chip carries out the pel array that produces after the opto-electronic conversion and view window zone thereof as shown in Figure 4.The definition of relevant characteristics of image and definite shown in Fig. 5 (edge direction data, edge direction situation).

The described coordinate system of patent of the present invention can freely be chosen, and described measuring method also is applicable to other picture pick-up device.

Claims (7)

1. be method and the device of pattern measurement with the three primary colours peak valley along the displacement of optical axis direction, comprise: the logical computing machine of a Daepori connects a computing machine camera, stepper motor and interface circuit thereof by its USB interface, it is characterized in that, it is on the axial displacement device formed of core by described stepper motor that this camera is installed in one, this stepper motor is connected to the RS232C interface of described computing machine by described stepper motor interface circuit, and described computer configuration has camera to take and according to three primary colours peak valley DATA REASONING axial displacement program.

2. according to claim 1 is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours peak valley, it is characterized in that described camera axial displacement device comprises:

Camera (1) is installed on the worktable (33), this worktable (33) and a long tap turning axle (34) are with the tap socket, tap turning axle (34) is installed on the big worktable (30) by bracing frame (31) and (32), and, tap turning axle (34) and bracing frame (31) and (32) all are the mode sockets with rotating shaft, and tap turning axle (34) can rotate at the socket place with bracing frame (31) and (32) but forward or backward displacement does not take place; A fixing gear (341) is arranged, the interlock mutually of the gear (42) above the rotating shaft (41) of it and stepper motor (40) on the tap turning axle (34); Stepper motor (40) also is installed on the worktable (30), and it is connected to the RS232C interface (8) of computer system (5) by stepper motor interface circuit (43).

According to claim 1 described be method and the device of pattern measurement with the three primary colours peak valley along the displacement of optical axis direction, it is characterized in that described camera is taken and comprised the method for following Measuring Object along the micro-displacement of the optical axis direction generation of described camera according to three primary colours peak valley DATA REASONING axial displacement program:

Step 1, with the form of bitmap (M * N, M, N ∈ positive integer), take the image of a frame testee, as the reference frame; First locations of pixels with this frame pel array upper left corner is an initial point, is the x direction of principal axis with to the right direction, and vertical downward direction is the y direction of principal axis, and the unit of the coordinate system of getting is the size of a pixel; Choose a zone at the middle section of described pel array, size is m ₀* n ₀, m ₀, n ₀The ∈ positive integer is referred to as view window, and the horizontal direction of the described pel array of its distance and the edge pixel of vertical direction respectively have h and v pixel, promptly have: m ₀+ 2h=M, n ₀+ 2v=N, h, v ∈ positive integer;

Step 2, for the pel array of above-mentioned reference frame, by pixel column, by the edge direction data of pixel column derivation along X-direction and Y direction, and with the binary numeral 001 of 3bit, 010 and 100 wherein positive limit, marginal and the 3rd class limits of expression respectively, so constituted corresponding described reference frame pel array about X-direction with about two frame edge direction data { reference of Y direction _x(x, y) } and { reference _y(x, y) }, wherein, subscript x or y represent the direction of the coordinate axis on institute edge respectively, all pixels in the change in coordinate axis direction view window that symbol " { } " expression is indicated along function subscript wherein (x, these data are preserved in a set of the edge direction data of y) locating;

Step 3, for above-mentioned two frame edge direction data, calculate the auto correlation matching factor of view window interior pixel array in the described reference frame respectively:

$\mathrm{auto}\_\mathrm{correlatio}{n}_x(a,b)=\underset{y=v+1}{\overset{v+1+n0}{\mathrm{\&Sigma;}}}\underset{x=h+1}{\overset{h+1+m0}{\mathrm{\&Sigma;}}}[{\mathrm{reference}}_x(x,y)\&CenterDot;{\mathrm{reference}}_x(x+a,y+b)]$

${\mathrm{auto}\_\mathrm{correlation}}_y(a,b)=\underset{y=v+1}{\overset{v+1+n0}{\mathrm{\&Sigma;}}}\underset{x=h+1}{\overset{h+1+m0}{\mathrm{\&Sigma;}}}[{\mathrm{reference}}_y(x,y)\&CenterDot;{\mathrm{reference}}_y(x+a,y+b)]$

In the formula, sign of operation is represented binary logic and computing, its operation result or be logical zero or for logical one, the pairing numerical value of value of logical operation function is wherein got in sign of operation " [] " expression, or is numerical value 0, or is numerical value 1, parametric variable a, the combination of b has determined the scale of associated match operator array, if get 3 * 3 associated match operator array: a=-1,0,1, b=-1,0,1, therefore, each will produce 9 auto correlation coefficient auto_correlation along each change in coordinate axis direction _x(a, b) and auto_correlation _y(a, b);

Step 4, according to the auto correlation matching factor of above-mentioned two frame edge direction data correspondences, search for respectively and under present body surface situation and illuminating position, can carry out matching ratio optimal viewing window pel array:

m _x＝m ₀±step，n _x＝n ₀±step，2h＝M-m _x，2v＝N-n _x

And m _y=m ₀± step, n _y=n ₀± step, 2h=M-m _y, 2v=N-n _y,

In the formula, subscript x, y represent respectively its value corresponding along X-direction and Y direction, step is the stepped parameter in the search procedure, the unlike signs of its front is determined by the direction of search; Get in this two class value big person and measure the scale of used view window array: m * n for this;

Step 5, for the pel array of above-mentioned reference frame, data according to its redness, green and blue component, respectively line by line, derive along the redness of X-axis and Y direction, green and edge direction data blueness by row, one has 3 * 2=6 frame edge direction data;

According to the edge direction data of above-mentioned three kinds of primary colours, derive respectively along the limit reflection condition of three kinds of primary colours of X-axis and Y direction, have 3 * 2=6 frame limit reflection condition; For view window zone wherein, use the number of their pairing peaks of accumulator count, paddy: N respectively _{RX axle peak}, N _{RX axle paddy}, N _{RY axle peak}And N _{RY axle paddy}, N _{GX axle peak}, N _{GX axle paddy}, N _{GY axle peak}And N _{GY axle paddy}, N _{BX axle peak}, N _{BX axle paddy}, N _{BY axle peak}And N _{BY axle paddy}, wherein, N (umber) represents number, R, G, B represent the red, green and blue look respectively; Add up above-mentioned totalizer count results and preserve it, be expressed as: N (i, j=0, forw=0, back=0), wherein, i=1,2,3...... represents the sequential counting of captured reference frame, also be the counting of measuring, j=0,1,2,3 ..., represent the counting of the sampling frame taken in the i time measuring process, variable forw (=0,1,2 ...) and back (=0,1,2 ...) represent stepper motor generation clockwise rotation described in the i time measurement and the pairing step-by-step impulse counting of anticlockwise rotation respectively, before this measures beginning, have: i=1, j=0, forw=0, back=0;

Step 6, measurement beginning: described computing machine is exported forw=1 digital pulse signal to described stepper motor interface circuit by an output control line FORWARD of its RS232C interface, control this stepper motor clockwise and rotate a step, then, take j=1 frame sample framing bit figure;

For the pel array of above-mentioned sampling frame,, respectively line by line, derive along the redness of X-axis and Y direction, green and edge direction data blueness, have 3 * 2=6 frame edge direction data by row according to the data of its redness, green and blue component;

According to the edge direction data of above-mentioned three kinds of primary colours, derive respectively along the limit reflection condition of three kinds of primary colours of X-axis and Y direction, have 3 * 2=6 frame limit reflection condition; For view window zone wherein, use the number of their pairing peaks of accumulator count, paddy: N respectively _{RX axle peak}, N _{RX axle paddy}, N _{RY axle peak}And N _{RY axle paddy}, N _{GX axle peak}, N _{GX axle paddy}, N _{GY axle peak}And N _{GY axle paddy}, N _{BX axle peak}, N _{BX axle paddy}, N _{BY axle peak}And N _{BY axle paddy}Add up above-mentioned totalizer count results and preserve it, be expressed as: N (i, j=1, forw=1, back=0);

Step 7, if: N (i, j=1, forw=1, back=0) 〉=N (i, j=0, forw=0, back=0), described computing machine is exported forw (=2,3 by an output control line FORWARD of its RS232C interface, ...) individual digital pulse signal is to described stepper motor interface circuit, it is progressive to control this stepper motor clockwise rotation, and each one step of clockwise rotation all takes and analyzes and respectively takes a sample before and after the comparison in the frame in the view window along all peaks of three kinds of primary colours of X-axis and Y direction and the number sum N (i of paddy, j=forw-1, forw-1, back=0) and N (i, j=forw, forw, back=0), preserve it, should have in this process: N (i, j=forw, forw, back=0) 〉=N (i, j=forw-1, forw-1, back=0), up to satisfying: N (i, j=forw, forw, back=0)＜N (i, j=forw-1, forw-1, back=0), at this moment, record (forw) _MAX=forw, simultaneously, described computing machine arrives described stepper motor interface circuit by another root output control line BACKWARD digital pulse signal of output (back=1) of its RS232C interface, control anticlockwise one step of rotation of this stepper motor, at this moment, this measures the preceding initial position of beginning relatively, and the camera of this device promptly is in the best object image-forming focal position in this measurement: FocusP=(forw) _MAX-back=(forw) _MAX-1, its result calculated is more than or equal to 0, the sense of rotation of representing described stepper motor in general is clockwise, in the sampling frame view window of this focal position correspondence along all peaks of three kinds of primary colours of X-axis and Y direction and the number sum of paddy is: N (i, j=(forw) _MAX-1, forw=(forw) _MAX-1, back=0), the tale result of the sampling frame of taking in the measuring process is: j=(forw) _MAX+ back=(forw) _MAX+ 1;

If: N (i, j=1, forw=1, back=0)＜N (i, j=0, forw=0, back=0), described computing machine is exported back=1 digital pulse signal to described stepper motor interface circuit by an output control line BACKWARD of its RS232C interface, control the anticlockwise rotation backward of this stepper motor, promptly get back to the initial position of this measurement, then, described computing machine continues output back (=2 by the output control line BACKWARD of its RS232C interface, 3 ...) individual digital pulse signal is to described stepper motor interface circuit, controls the further anticlockwise rotation of this stepper motor, in this process, one step of each anticlockwise rotation all takes and analyzes and respectively takes a sample before and after the comparison in the frame view window along all peaks of three kinds of primary colours of X-axis and Y direction and number sum N (i, j=back+1, the forw=1 of paddy, back) and N (i, j=back, forw=1, back=back-1), should have: N (i, j=back+1, forw=1, back=back) 〉=N (i, j=back, forw=1 back=back-1), preserves it, so continue, up to satisfying: N (i, j=back+1, forw=1, back)＜N (i, j=back, forw=1, back-1), at this moment, record: (back) _MAX=back, simultaneously, described computing machine arrives described stepper motor interface circuit by another root output control line FORWARD digital pulse signal of output (forw=2) of its RS232C interface, control this stepper motor clockwise and rotate a step, at this moment, this measures the preceding initial position of beginning relatively, and the camera of this device promptly is in the best object image-forming focal position in this measurement: FocusP=forw-(back) _MAX=2-(back) _MAXIts result calculated is a negative value, the sense of rotation of representing described stepper motor is anticlockwise, in the sampling frame view window of this focal position correspondence along all peaks of three kinds of primary colours of X-axis and Y direction and the number sum of paddy is: N (i, j=((back) _MAX-1)+1=(back) _MAX, forw=1, back=(back) _MAXThe tale result of the sampling frame of-1), taking in the measuring process is: j=forw+ (back) _MAX=2+ (back) _MAX

Integrate, this measures the preceding initial position of beginning relatively, and the object that this measurement is obtained along the displacement of the optic axis direction generation of described camera is: Δ z (i)=forw-back,

The value of counter forw and back is count results last in this measuring process in the aforementioned calculation formula, result of calculation has the symbol of plus or minus, the displacement that taken place of the expression direction of advancing or retreating respectively along optic axis, corresponding to the sense of rotation of described stepper motor (promptly clockwise or anticlockwise), specifically determine by the arrangement of the axial displacement device of stepper motor;

Total displacement is: Δ Z ₀(i)=Δ Z ₀(i-1)+Δ z (i)

Wherein, Δ Z ₀(i-1) measure the axial displacement of accumulation before for this;

Step 8, prepare surveying work next time: measure time counter i=i+1, the number sum of getting all peaks of measuring the interior three kinds of primary colours along X-axis and Y direction of the corresponding object image-forming frame of the best object image-forming focal position view window of determining for the i time and paddy is as new witness mark value:

N(i，j＝0，forw＝0，back＝0)＝N(i，j＝(forw) _MAX-1，forw＝(forw) _MAX-1，back＝0)，

Or N (i, j=0, forw=0, back=0)=

N(i，j＝((back) _MAX-1)+1＝(back) _MAX，forw＝1，back＝(back) _MAX-1)；

Step 9, jump to step 6, continue to measure.

4. according to claim 3 is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours peak valley, it is characterized in that described camera is taken and according to the definition of edge direction data described in the step of three primary colours peak valley DATA REASONING axial displacement program is:

In the pel array, along X-axis or along Y direction, if the light intensity value of a pixel is than the also little error margin value error of second corresponding light intensity value of pixel of its back, if promptly

I (X, Y)＜I (X+2, Y)-error or I (X, Y)＜I (X, Y+2)-error

Then define and have this axial positive limit, an edge between these two pixels; If the light intensity value of a pixel is than the also big error margin value error of second corresponding light intensity value of pixel of its back, if promptly

I (X, Y)＞I (X+2, Y)+error or I (X, Y)＞I (X, Y+2)+error

Then define between these two pixels and to have an edge this is axial marginal; So the limit that obtains is positioned at this pixel first locations of pixels afterwards, also promptly is positioned on that pixel in the centre position that participates in two pixels relatively; If second corresponding light intensity value of pixel of certain light intensity value of a pixel and its back is approaching, its value differs and is no more than an error margin value error, if promptly

I(X+2，Y)-error≤I(X，Y)≤I(X+2，Y)+error

Or I (X, Y+2)-error≤I (X, Y)≤I (X, Y+2)+error,

Then think not have corresponding " limit " along this direction of principal axis between these two pixels, or be referred to as the 3rd class limit;

Along some change in coordinate axis direction, all positive limit of corresponding pixel column or pixel column, marginal and the 3rd class limit form this row maybe these row along the edge direction data of this change in coordinate axis direction; Error margin value in the above-listed formula can be predisposed to a little numerical value, for example: error=10 according to concrete light conditions; There are not the edge direction data in four limits in the pel array and the location of pixels on the angle.

5. according to claim 3 is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours peak valley, it is characterized in that described camera is taken and comprised according to the method for searching for optimal viewing window pel array described in the step of three primary colours peak valley DATA REASONING axial displacement program:

For the view window of described pel array and k * k (k ∈ positive integer) associated match operator array (a b), can produce k * k auto correlation matching factor along certain change in coordinate axis direction, by following inequality these auto correlation matching factors relatively:

auto_correlation(a，b)≥auto_correlation(0，0)×similarity

In the formula, similarity has described the similarity degree of the pel array of view window and its contiguous identical scale, for example gets similarity=60%, can set in advance, and also can debug and selects according to the quality on light conditions and measured object surface;

If the auto correlation coefficient that satisfies above-mentioned inequality more than k * k * 1/3, needs to enlarge the capable and step row of each step of scope of view window: make m=m ₀+ step, n=n ₀+ step, recomputate the auto correlation coefficient of new view window, and carry out above-mentioned comparison, up to the no more than k * k of auto correlation matching factor that satisfies above-mentioned inequality * 1/3, at this moment, 2h=M-m, 2v=N-n, wherein, step is a stepped parameter, initial value is 1, needs the scale of expansion view window just to increase by 1 at every turn; If exceed predetermined scope in the frame, also do not find suitable view window, think that then the quality of this this part reflecting surface of object is unsuitable for the surveying work of this device, and provide the prompting warning;

If satisfy the no more than k * k of auto correlation matching factor of above-mentioned inequality * 1/3, the architectural feature on surface that subject is described is enough meticulous, value between the neighborhood pixels can be distinguished, can further attempt dwindling the capable and step row of each step of scope of view window, to reduce amount of calculation: make m=m ₀-step, n=n ₀-step recomputates the auto correlation coefficient of view window, and carries out above-mentioned comparison, the parameter s of going forward one by one tep is each to increase by 1, the number that satisfies the auto correlation coefficient of above-mentioned inequality up to selected view window zone is not less than k * k * 1/3, at this moment, thinks to have searched optimal viewing window pel array.

6. according to claim 3 is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours peak valley, it is characterized in that described camera is taken and according to the definition of edge direction data red, green or blue described in the step of three primary colours peak valley DATA REASONING axial displacement program is:

Component data according to one of red in the pel array, green or these three kinds of primary colours of blueness, along X-axis or along Y direction, if certain three primary colours component value of a pixel is than the also little error margin value error of the corresponding three primary colours component value of second pixel of its back, if promptly:

I (X, Y) _Red＜I _Red(X+2, Y)-error or I (X, Y) _Red＜I (X, Y+2) _Red-error

I (X, Y) _Green＜I _Green(X+2, Y)-error or I (X, Y) _Green＜I (X, Y+2) _Green-error

I (X, Y) _Blue＜I _Blue(X+2, Y)-error or I (X, Y) _Blue＜I (X, Y+2) _Blue-error

Then define and have a positive limit redness, green or blue between these two pixels; If certain three primary colours component value of a pixel is than the also big error margin value error of the corresponding three primary colours component value of second pixel of its back, if promptly: I (X, Y) _Red＞I _Red(X+2, Y)+error or I (X, Y) _Red＞I (X, Y+2) _Red+ error

I (X, Y) _Green＞I _Green(X+2, Y)+error or I (X, Y) _Green＞I (X, Y+2) _Green+ error

I (X, Y) _Blue＞I _Blue(X+2, Y)+error or I (X, Y) _Blue＞I (X, Y+2) _Blue+ error

Then define and have the marginal of a redness, green or blueness between these two pixels; So the limit that obtains is positioned at this pixel first locations of pixels afterwards, also promptly is positioned on that pixel in the centre position that participates in two pixels relatively; If the corresponding three primary colours component value of second pixel of certain three primary colours component value of a pixel and its back is approaching, its RGB component value differs and is no more than an error margin value error, if promptly:

I (X+2, Y) _Red-error≤I (X, Y) _Red≤ I (X+2, Y) _Red+ error

Or I (X, Y+2) _Red-error≤I (X, Y) _Red≤ I (X, Y+2) _Red+ error;

I (X+2, Y) _Green-error≤I (X, Y) _Green≤ I (X+2, Y) _Green+ error

Or I (X, Y+2) _Green-error≤I (X, Y) _Green≤ I (X, Y+2) _Green+ error;

I (X+2, Y) _Blue-error≤I (X, Y) _Blue≤ I (X+2, Y) _Blue+ error

Or I (X, Y+2) _Blue-error≤I (X, Y) _Blue≤ I (X, Y+2) _Blue+ error;

Then think not have " limit " of this color wavelength correspondence between these two pixels, or be referred to as the limit of the 3rd this color of class; Along some change in coordinate axis direction, the edge direction data of this direction redness are formed on the positive limit of all redness and red limit marginal and the 3rd class redness, the edge direction data of this direction green are formed on the positive limit of all greens and green limit marginal and the 3rd class green, and the edge direction data of this direction blueness are formed on the positive limit of all bluenesss and blue limit marginal and the 3rd class blueness; Error margin value in the above-mentioned formula can be predisposed to a little numerical value, for example: error=10 according to concrete light conditions; There are not the edge direction data in four limits in the pel array and the location of pixels on the angle.

7. according to claim 3 is method and the device of pattern measurement along the displacement of optical axis direction with the three primary colours peak valley, it is characterized in that, described camera take and according to described in the step of three primary colours peak valley DATA REASONING axial displacement program along the limit reflection condition of three kinds of primary colours of X-axis and Y direction, it is defined as:

According to redness, green or the blue edge direction data of selected observation row with the pixel of observation row, along X-axis or along Y direction, if continuous two or more than the positive limit of certain primary colours of two, or continuous two or more than and then these primary colours marginal after the 3rd class limit of these primary colours of two, be referred to as the first kind limit reflection condition of these primary colours, promptly think the peak that has these primary colours in this position; If continuous two or marginal more than certain primary colours of two, or continuous two or more than the and then positive limit of these primary colours after the 3rd class limit of these primary colours of two, be referred to as the second class limit reflection condition of these primary colours, promptly think the paddy that has these primary colours in this position; Along X-axis or along Y direction, its all peak of one of three kinds of primary colours and these primary colours of paddy composition diagram picture frame are along the limit reflection condition of this change in coordinate axis direction.

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