CN1031892A - Six-contact type high-precision planeness-measuring method and device - Google Patents

Abstract

Six-contact type high-precision planeness-measuring method and device thereof adopt the reference datums that the conduct of determined plane is all measured when measuring for the first time.So be not subjected to measured piece position, the variation of moving situation and the influence of other factors.Measuring accuracy height, but and continuous automatic measurement.Data can be by handling after the microcomputer collection in real time, is suitable for the flatness of the large-scale or ultra-large workpiece of in-site measurement.

Description

Six-contact type high-precision planeness-measuring method and device

The invention belongs to method measuring flatness and instrument.

The measurement of planeness of big machinery piece surface, the domestic and international method of using always is level meter method and collimator method at present.The level meter method is to adopt the piecemeal measurement of pitch method, relies on artificial reading, and Measuring Time is long, and precision is low.Collimator method instrument commonly used is auto-collimator and laser collimator, and measuring process and level meter method are similar, and main frame is motionless, and receiving target then bit by bit moves on measured surface, and affected by environment bigger, Measuring Time is long, and precision is not high yet.These two kinds of methods all inconvenience realize measuring automatically and the processing of microcomputer image data.

The objective of the invention is to develop a kind of flatness that is suitable for big plane and super large plane is high-precision and can measure automatically method and instrument.

Formation of the present invention is to adopt three fixedly gauge head and three moving gauge heads, be arranged to two rows, three gauge heads of every row, wherein first row arranges two fixedly gauge heads continuously, a fixedly gauge head is arranged in the second row centre position, other positions are arranged three moving gauge heads respectively, and the distance between the gauge head is equidistant.

But the measurement mechanism nationality of arranging gauge head in a manner described helps conventional drive method to move continuously on measured surface, and measures at required measurement point.

Moving gauge head can be contact as inductance probe, grating gauge head etc.Also can be contactless, as the electric capacity gauge head.

For ease of the explanation principle of work, that description of drawings is as follows:

Fig. 1 is the measurement mechanism synoptic diagram.A, B, E is fixing probe location, C, D, F is for moving probe location.A is the distance between gauge head.1 is the chassis, and 2 are fixing gauge head, and 3 for moving gauge head.

Fig. 2 is in the measuring process, the residing diverse location of measurement mechanism gauge head.A1 wherein, B1, C1, D1, E1, F1; B1, B2, C2, D2, E2, F2; B2, B3, C3, D3, E3, F3 etc. are respectively when measuring for three times, six residing positions of gauge head.The fluctuating situation of curve representation measured surface.α when measuring for the first time, fixing gauge head A1, B1, the determined plane of E1 is the reference data plane in the whole measuring process, straight line MN ∥ M ' N ' and on the α of plane.

When Fig. 3 is measurement plane, the moving line of measurement mechanism.A wherein, B, C, D, E, F; The position of gauge head when A ', B ', C ', D ', E ', F ' are respectively measurement mechanism diverse location of living in.

The three-dimensional stereo topography figure of Fig. 4 measured surface.

The location drawing of three high low spots in the surperficial measured point of the tested steel plate of Fig. 5.

Operation principle of the present invention is as follows:

If A, B, three of E fixedly gauge head determined plane when beginning to measure are datum plane α, before measurement, measurement mechanism is placed on the standard optic plane glass crystal face, six measuring points are contacted with it, and the reading of adjusting moving gauge head be " zero ", in measuring process as the reading of moving gauge head be that " zero " then represents at 6 all in datum plane α, be not the position deviation datum plane that " zero " then do not represent this measuring point such as reading. Figure 2 shows that the position of each gauge head in the measuring process. Fixing gauge head A1 when measuring for the first time, B1, E1 contacts measured surface, A1, B1,3 definite planes of E1. Be datum plane α, by A1, B1 makes the MN straight line. This line is on datum level α. Make M ' N ' line parallel MN line by E1, and also on datum level α. This moment as three moving gauge head C1, D1, the reading of F1 then represent when all being " zero " tested 6 all on datum level α. Be tested 6 at grade. Such as C1B2 among Fig. 2, D1D ' 1, and F1E2 is the distance of three moving gauge heads and measured surface, namely represent these 3 not with A1, B1,3 of E1 are in same plane. Suppose first row gauge head A1, B1, C1 represents with Y that by the distance of surface, measured point to datum level α the reading of moving gauge head represents with X. Second row gauge head D1, E1, F1 is represented with Y ' by the distance of measured point to datum plane α, moving gauge head reading X ' expression. Then by finding out among Fig. 2 at A1 point Y1=0, at B1 point Y2=0, at the C1 point | Y3|=C1B2=|X1|, i.e. Y3=X1. At the D1 point | Y ' 1|=D1D ' 1=|X ' 0|, namely Y ' 1=X ' 0. At E1 point Y ' 2=0. At the F1 point | Y ' 3|=F1E2=|X ' 1|, namely Y ' 3=X ' 1. So when measuring for the first time, the distance of six measuring points and datum level is respectively Y1, Y2, Y3, Y ' 1, and Y ' 2, and Y ' 3, wherein Y1=Y2=Y ' 2=0. Y3=X1, Y ' 1=X ' 0, and Y ' 3=X ' 1. X1, X ' 0, and X ' 1 is the reading of gauge head, so the numerical value of six measured points is all as can be known.

One segment distance a when measuring for the second time moves right measurement mechanism. Be in B1, B2, C2, D2, E2, the position of F2. From the first row gauge head, because of C2B3 vertical reference face (being that the B3 point is to the vertical line of datum level), so △ B1C2C ' 2 is right angled triangle. Be distance between each gauge head because of B1B2=B2C2=a(a again) ∴ C2C ' 2=2C1B2 B3C ' 2 for the measured point to the distance of datum level α apart from Y4. Know B3C ' 2=B3C2-C2C ' 2 ∴ B3C ' 2=B3C2-2C1B2 by figure

Because B3C ' 2=|Y4| C1B2=|Y3| B3C2=|X2|(is the reading of gauge head C2 when measuring for the second time) substitution can get:

｜Y4｜＝｜X2｜-｜2Y3｜

Sign convention: to Y and Y ' value is " just " more than reference plane α.Otherwise be " bearing ".More than the determined plane of gauge head is " just " to X and X ' value fixedly at three.Otherwise be " bearing ".So Y4 as can be known, X2 is for just.Y3 is for negative.

∴ can get Y4=X2+2Y3=2Y3+X2

This formula can be write as Y4=2Y3-Y2+X2 (1) because of Y2=0.

From second row's gauge head, make F1F ' 1=C1B2 and cross F ' 1 make F ' 1F ' " 2 ∥ E2F2, then quadrilateral B2C2C ' 2C1 ≌ quadrilateral F ' 1F ' " 2F ' 2F1(∵ F1F ' 1

C1B2, " 2 F ' 2 and C2C ' 2 be vertical reference plane α, again ∵ E2F2 for F '

B2C2, F ' 1F ' " 2 E2F2 ∴ F ' 1F ' " 2

B2C2) ∴ F ' " 2F ' 2=C2C ' 2

Know E3F ' 2=F ' " 2F ' 2-F ' " 2E3=C2C ' 2-F ' " 2E3 by figure

And by preceding knowing C2C ' 2=2B2C1 so substitution can get E3F ' 2=2B2C1-F ' " 2E3

Again because of F ' " 2E3=F2E3-F2F ' " 2, F2F ' " 2=E2F ' 1(parallelogram opposite side)

" E2F ' 1=E2F1-F ' 1F1 is known by figure in 2E3=F2E3-E2F ' 1 to ∴ F '

∴ F′″2E3＝F2E3-（E2F1-B2C1）（∵F′1F1＝B2C1）

∴ E3F′2＝2B2C1-（F2E3-E2F1+B2C1）

＝B2C1-F2E3+E2F1

Because of E3F ' 2=|Y ' 4|, B2C1=|Y3|, F2E3=|X ' 2|, E2F1=|Y ' 3| event substitution can get | Y ' 4|=|Y3|-|X ' 2|+|Y ' 3|

Know Y ' 4 by symbolic rule, Y ' 3 and Y3 are " bearing ".X ' 2 is " just ".

So can get-Y ' 4=-Y3-Y ' 3-X ' 2

Be Y ' 4=Y3+Y ' 3+X ' 2

This formula can be write as Y ' 4=Y3-Y2+Y ' 3+X ' 2 (2) because of Y2=0.

In formula (1), in (2), Y3, Y ' 3 is a given value.X2, X ' 2 is moving gauge head reading.So when measuring for the second time, can pass through (1), (2) formula calculate Y4, the numerical value of Y ' 4 that is to say measuring point C2, F2 departs from the numerical value of reference field.

Again measurement mechanism is moved right one apart from a when measuring for the third time.Promptly be in B2, B3, C3, D3, E3, F3 position.From first row's gauge head, make C1C " 3 ∥ B2C3, C1C " 3 with C ' 3C3 extensions meet at C " 3, and meet at C " 2 with the C2B3 extensions.

Know B4C ' 3=C " 3C ' 3-C " 3B4 by figure

" 3 ⊥ MN and B2B3=B3C3, i.e. C1C " 2=C " 2C " 3) again because of C " 2C ' 2=C " 2B3+B3C ' 2 at △ C1C ' 3C " C in 3 " 3C ' 3=2C ' 2C " 2 (∵ C ' 2C " 2 ⊥ MN.C ' 3C

∵C″2B3＝C1B2 ∴C″2C′2＝C1B2+B3C′2

∴C″3C′3＝2（C1B2+B3C′2）

Again because of C " 3B4=C " 3C3+C3B4 C " 3C3=C1B2

∴C″3B4＝C1B2+C3B4

∴B4C′3＝2（C′2B3+C1B2）-C″3B4

＝2C′2B3+2C1B2-（C1B2+C3B4）

＝2C′2B3+C1B2-C3B4

Because of B4C ' 3=|Y5| C ' 2B3=|Y4| C1B2=|Y3| C3B4=|X3| event substitution can get | Y5|=2|Y4|+|Y3|-|X3|

Know Y5 by symbolic rule, Y4 is " just ", and Y3, X3 are " bearing "

∴Y5＝2Y4-Y3+X3 （3）

From second row's gauge head, make F ' 2F " 2

C ' 2B3 also crosses F " 2 make F " 2F ' 3 ∥ E3F3

∵ E3F again " 2 and F3F ' 3 vertical reference plane α.∴F″2F′3

E3F3

E4E ' 4=E4F3-E ' 4F3 E ' 4F3=E ' 4F ' 3-F3F ' 3 as we know from the figure

Because of quadrilateral F " 2F ' 2E ' 4F ' 3 ≌ quadrilateral B3C ' 2C ' 3C3 (∵ F ' 2F " 2

C ' 2B3, F ' 2E ' 4

C ' 2C ' 3 other corresponding sides also are parallel to each other, and " 2F ' 3 ∥ B3C3, E ' 4F ' 3 ∥ C ' 3C3) for F

∴E′4F′3＝C′3C3 ∴E′4F3＝C3C′3-F3F′3

" 2F ' 3F3E3 is a parallelogram because of quadrilateral F

∴F3F′3＝E3F″2＝E3F′2+F′2F″2 ∵F′2F″2＝C′2B3

∴F3F′3＝E3F′2+C′2B3

∴E4E′4＝E4F3-（C3C′3-F3F′3）＝E4F3-C3C′3+F3F′3）

＝E4F3-C3C′3+E3F′2+C′2B3

∵E4E′4＝｜Y′5｜，E4E3＝｜X′3｜，E3F′2＝｜Y′4｜，C′2B3＝｜Y4｜

C ' 3C3=|2Y4+Y3|(is because of C3C ' 3=C ' 3C " 3-C3C " 3, and

C′3C″3＝2｜（Y4+Y3）｜ C3C″3＝｜Y3｜

∴C3C′3＝｜2Y4+2Y3-Y3｜＝｜2Y4+Y3｜）

So substitution gets | Y ' 5|=|X ' 3|-|2Y4+Y3|+|Y ' 4|+|Y4|

＝｜X′3｜-｜Y4｜-｜Y3｜+｜Y′4｜

Press symbolic rule Y ' 5, Y ' 4, Y3, and X ' 3 is " bearing ", and Y4 is " just ".

So can get-Y ' 5=-X ' 3-Y4+Y3-Y ' 4

Get Y ' 5=Y4-Y3+Y ' 4+X ' 3 (4)

Removing Y5 in the same reason (3), (4) formula, all is known number outside the Y ' 5.So can try to achieve Y5 by calculating, Y ' 5.

Conclusion (1), (3) and (2), (4) formula can be found out:

Y4＝2Y3-Y2+X2 （1）

Y5＝2Y4-Y3+X3 （3）

Y′4＝Y3-Y2+Y′3+X′2 （2）

Y′5＝Y4-Y3+Y′4+X′3 （4）

So can get general formula Y _i=2Y _I-1-Y _I-2+ X _I-2

Y′ _i＝Y _i-1-Y _i-2+Y′ _i-1+X′ _i-2

Concrete measuring process is example with the rectangle plane.As Fig. 3.N is capable apart from being divided into for the point that tested plane is measured on demand, M row and to make M be even number, because of measurement point is that distance between the measurement mechanism gauge head can be adjusted apart from a, can determine a value so can obtain its highest common factor from the both sides length value of measured surface.Before measuring device is placed on the reading of adjusting three moving gauge heads on the standard optical flat face and is " zero ".Measure from point " 1 " for the first time, read the reading of three moving gauge heads.To install to the right (according to the direction of arrow) when measuring for the second time and move a bit, and read moving gauge head reading and can get 2 the reading (be X2, X ' 2) newly and then a distance that moves right apart from a.Read X3, X ' 3, measure the edge so continuously after, will install with the E point is the center of circle, turns clockwise 90 °.A ', B ', C ', D ', E, F ' position.Can newly read like this two readings (being F ', C ' point).To install then along the direction of arrow and move down an a distance, the readable again reading that gets at 2.Proceed to lower limb so continuously, measurement mechanism is moved be put into the upper left corner, behind lower limb, measurement mechanism is moved be put into the middle part, top again, measure downwards in the direction of arrows, can survey the reading of complete plane each point to the edge along arrow measurement successively downwards.The data of measured each point are obtained its naturalization value by general formula, and the deviation value of the reference field α when promptly each measured point was measured with respect to the first time calculates flatness size or linearity size with the gained data by least square method (or additive method) then.

Precision analysis to measuring method of the present invention is as follows:

Measuring accuracy comprise when every bit being measured with device of the present invention error and to the error sum of measurement data after row is handled.

The moving gauge head of measurement mechanism of the present invention can adopt gauge heads such as inductance type, condenser type.Its error of inductance probe of commodity is 0.1 μ m at present.Be the reading error δ x=0.1 μ m of every bit.

Because of the survey number apart from error delta 1＜0.1 μ m that is produced by the A/D conversion with MICROCOMPUTER PROCESSING

Press general formula Y _i=2Y _I-1-Y _I-2+ X _I-2

Y′ _i＝Y _i-1-Y _i-2+Y′ _i-2+X′ _i-1

Then the error of a certain measuring point is:

${\mathrm{\δ}}_{\mathrm{yi}}^{\′}=\±\sqrt{2{\left({\mathrm{\δ}}_{\mathrm{yi}-1}\right)}^2+{\left({\mathrm{\δ}}_{\mathrm{yi}-2}\right)}^2+{\left({\mathrm{\δ}}_{\mathrm{xi}-2}\right)}^2}$

$\mathrm{=\pm }\sqrt{{\mathrm{2(0.1)}}^2\mathrm{+(0.1)}{}^2\mathrm{+(0.1)}{}^2}\mathrm{=\pm }\sqrt{\mathrm{0.04}}{\mathrm{=\pm 0.2}}^{\mathrm{\mu \; m}}$

${\mathrm{\δ}}_{\mathrm{yi}}^{\′}=\±\sqrt{2{\left({\mathrm{\δ}}_{\mathrm{yi}-1}\right)}^2+{\left({\mathrm{\δ}}_{\mathrm{yi}-2}\right)}^2+{\left({\mathrm{\δ}}_{y^{\′}i-2}\right)}^2+{\left({\mathrm{\δ}}_{x^{\′}i-1}\right)}^2}$

$\mathrm{=\pm }\sqrt{{\mathrm{(0.1)}}^2\mathrm{+(0.1)}{}^2\mathrm{+(0.1)}{}^2\mathrm{+(0.1)}{}^2}\mathrm{=\pm }\sqrt{\mathrm{0.04}}{\mathrm{=\pm 0.2}}^{\mathrm{\mu \; m}}$

Add that the error delta 1＜0.1 after the MICROCOMPUTER PROCESSING gets δ 1=0.1 μ m

The ∴ error

${\delta }_y\mathrm{=\pm }\sqrt{{\mathrm{(\delta }}_{\mathrm{y\; i}}){}^2{\mathrm{+\; (\delta }}_1){}^2}\mathrm{=\pm }\sqrt{{\mathrm{(0.2)}}^2\mathrm{+(0.1)}{}^2}$

$\mathrm{=\pm }\sqrt{\mathrm{0.04+0.01}}{\mathrm{=\pm 0.224}}^{\mathrm{\mu \; m}}$

Because measuring process is multimetering, may produce accumulated error, but this error to be relevant with the measure dot number of a direction, and to be at random, the situation during to the usefulness level measurement is similar, promptly multiply by with former measuring error again $\sqrt{n}$ / 2(n is the measure dot number of a direction).

So the total error with measurement mechanism of the present invention is:

$\mathrm{\delta \; =\pm }\frac{\sqrt{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="881049891\_DRIMG1.png,881049891\_DRIMG3.png"\; state="\{\{state\}\}">n</figure-callout>}}}{2}{\delta }_y\mathrm{=\pm }\sqrt{n}\frac{\mathrm{0.224}}{2}\mathrm{=\pm 0.112}\sqrt{n}{}^{\mathrm{\mu \; m}}$

The precision index of domestic level meter of producing and autocollimator is as follows at present:

Level meter

Autocollimator

Press the gauging instrument design theory as can be known, accuracy of instrument is 1/3～1/10 of an instrument readings scale value.Promptly be lower than 3 times to 10 times of scale value.So the domestic and international at present level meter of producing and the precision of autocollimator, be preferably ± 2 * 10 ^-6M/m.

Advantage of the present invention is:

1. measuring accuracy height.As preceding analysis, be with apparatus of the present invention measurement total error $\sqrt{n}$ μm。1 meter * 1 meter n=5(is pressed level meter point distance).Then total error is ± 0.23 μ m, promptly ± 0.23 * 10 ^-6M/m.And measure its error with level meter at present commonly used and collimator and be preferably ± 2 * 10 ^-6M/m.

2. but continuous automatic measurement.Be suitable for and measure large-sized surface.Owing to can measure automatically, required time is shorter, so can not influence measuring accuracy owing to the temperature variation of measured piece, is specially adapted to big of in-site measurement.

This measuring method be when measuring for the first time three fixedly gauge head and the formed plane of measured surface contact point as reference field.After this not because of the precision of the variation of measured piece position (as tilting and low-speed motion etc.) and other auxiliary equipment, environmental change and influence measuring accuracy.

4. the present invention to testee surface configuration and size without limits.From hundreds of millimeter to tens meter or all be suitable for greatlyyer.

Embodiments of the invention are as follows:

Measured surface is 400 * 450mm with the processing of Bao bed ²Steel plate.The surface sand papering.The reading of moving gauge head is by microcomputer sampling, and processing in real time.Calculate flatness size and draw the three-dimensional stereo topography figure (Fig. 4) of measured surface by least square method, Fig. 5 is the three high one low locations drawing of this steel plate measured point.

The flatness that records with device of the present invention is 43.45 μ m.Measure its flatness of same steel plate result of calculation 41.8 μ m with the level meter method.

Attached each point measurement data is as follows:

F＝43.45μm

0 -12.7125 -23.525 -30.8375 -35.15 -35.5625 -34.375 -32.6875 -26.1 -2.4 -14.8125 -25.225 -31.6375 -34.95 -35.3625 -33.775 -31.3875 -26.8 -7.8 -18.3125 -27.625 -34.5375 -39.95 -39.3625 -35.475 -28.8875 -20.4 -10.9 -21.1125 -29.825 -38.8375 -43.45 -43.1625 -38.875 -32.1875 -24.2 -12.5 -22.0125 -27.82 -31.2375 -31.05 -29.2625 -26.075 -19.7875 -11.7 -10.5 -19.5125 -25.825 -30.5375 -32.65 -31.0625 -27.375 -21.3875 -13.4 -8.99999 -18.1125 -24.525 -27.7375 -28.45 -25.9625 -20.375 -12.0875 0 -6.89999 -16.5125 -24.125 -27.9375 -28.55 -25.1625 -20.175 -11.4875 0

Claims (2)

1, a kind of contact measuring apparatus of being made up of fixing gauge head, moving gauge head, chassis is characterized in that gauge head is arranged to two rows, three gauge heads of every row.Wherein first row arranges two fixedly gauge heads continuously, and a fixedly gauge head is arranged in the second row centre position, and other positions are arranged three moving gauge heads respectively, and the distance between the gauge head is equidistant.

2, press claims 1 said measurement mechanism, it is characterized in that moving gauge head can be contact as inductance probe, the grating gauge head also can be contactless as the electric capacity gauge head.

Images