CN109443249A - High precision roll angle measurement method and device based on transmission grating - Google Patents
High precision roll angle measurement method and device based on transmission grating Download PDFInfo
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- CN109443249A CN109443249A CN201811485069.2A CN201811485069A CN109443249A CN 109443249 A CN109443249 A CN 109443249A CN 201811485069 A CN201811485069 A CN 201811485069A CN 109443249 A CN109443249 A CN 109443249A
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- transmission grating
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/26—Measuring arrangements characterised by the use of optical techniques for measuring angles or tapers; for testing the alignment of axes
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Abstract
High precision roll angle measurement method and device based on transmission grating belong to precision instrument manufacture and precision measurement measurement technology；The present invention, as Sensitive Apparatus, realizes the roll angle variable quantity measurement of Sensitive Apparatus using one-dimensional plane transmission grating；The present invention solves the deficiencies of existing method is low with the measurement accuracy in device, operating distance is short, carries out variate using diffractive beam, eliminates the measurement error introduced by light beam of light source angle drift；Light beam to be measured is parallel with optical axis, greatly increases the operating distance of measuring device, while detecting structure more jam-packed being made to gather；Laser beam passes through transmission grating effect twice, and systematic survey resolving power is made to be doubled；The measuring system eliminates the influence of deflection angle and pitch angle to rotation angular measurement；The grating of not collinear pair of replacement can meet the requirement of different measurement accuracy.
Description
Technical field
The invention belongs to precision instrument manufacture and precision measurement field of measuring techniques, relate generally to a kind of based on transmission grating
High precision roll angle measurement method and device.
Background technique
Precision small angle measurement is basis and the important component of geometry metrology detection, in micro-electronic manufacturing, accurate dress
Prepare make and calibrate, optical element processing and detection, the processing and assembly of aerospace and the medium-and-large-sized equipment of shipping industry, with
And the fields such as scientific research and engineering manufacture are widely used, with the continuous development of related fields, to the measurement accuracy of angle
Requirement with measurement stability also increases accordingly.
Generally there are the angular errors and beat angle error, pitching angle error and roll angle mistake in three directions for mechanical movement
Difference.Wherein, deflection angle and pitching angle error can be measured by the measuring techniques such as laser interference method and auto-collimation method,
Measuring technique is mature and has been commercialized；It is former according to laser interference principle and Auto-collimation angular measurement for rolling angle error
Reason all can not directly measure rolling angle error, therefore be difficult to obtain the precise measurements of rolling angle error, so high-precision
The rolling measurement of degree need further to study.
Summary of the invention
The object of the invention is in order to overcome the shortcomings of in existing method and device, to realize and reaching high-precision rolling
The purpose of angular measurement proposes a kind of High precision roll angle measurement method and device based on transmission grating.
The object of the present invention is achieved like this: the High precision roll angle measurement method based on transmission grating includes following step
It is rapid:
1., laser light source issue light beam collimated light beam is formed after collimator objective；
2., the collimated light beam after one-dimensional plane transmission grating, generate positive first-order diffraction light beam and negative first-order diffraction
Light beam is rigidly connected between the one-dimensional plane transmission grating and platform to be measured；
3., 2. described in positive first-order diffraction light beam and negative one grade diffracted beam by one group of diagonal line it is orthogonal partially
One group of outgoing beam parallel with positive first-order diffraction light beam and negative one grade diffracted beam is obtained after vibration light splitting microscope group；
4., 3. described in the outgoing beam parallel with positive and negative first-order diffraction light beam again pass by transmission grating, obtain one group
The diffracted beam parallel with optical axis；
5., 4. described in one group of diffracted beam parallel with optical axis formed after lens focus acts on two it is to be detected
Hot spot, while detecting using photodetector the location information of hot spot to be detected；
6., when platform to be measured occur rolling when, utilize photodetector detection 5. described in two hot spots to be detected
Change in location information, the change in location information of hot spot is sent into computer after signal processing circuit is handled, and calculating is rolled
The changing value of corner；
The roll angle γ of platform to be measured is obtained as follows:
In formula: Δ d+1For the position in measuring beam direction hot spot y on photodetector A in two neighboring sampling period
Difference；Δd-1For the alternate position spike in measuring beam direction hot spot y on photodetector B in two neighboring sampling period；F is to focus thoroughly
The focal length of mirror A and condenser lens B；Sin Ф is the wavelength of laser and the ratio of one-dimensional plane transmission grating grating constant.
The structure of High precision roll angle measuring device based on transmission grating is: laser, collimation lens, one-dimensional plane are saturating
Grating is penetrated to be arranged successively along the direction of propagation light a；The one-dimensional plane transmission grating transmission plane is vertical with incident beam；It is described inclined
Vibration spectroscope A, polarization spectroscope B are placed on rear side of one-dimensional plane transmission grating, and polarization spectroscope A, polarization spectroscope B diagonal line
It is mutually perpendicular to, and is 45 ° with laser optical axis angle；Positive first-order diffraction light beam b successively passes through polarization spectroscope A, polarization spectro
It is emitted after mirror B reflection, obtained outgoing beam e is parallel with positive first-order diffraction light beam b；Negative one grade diffracted beam c successively passes through partially
It is emitted after vibration spectroscope B, polarization spectroscope A, obtained outgoing beam d is parallel with negative one grade diffracted beam c；The emergent light
Beam d and outgoing beam e again pass by one-dimensional plane transmission grating, obtain the diffracted beam f and diffraction parallel with collimated light beam a
Light beam g；Diffracted beam f forms hot spot to be detected in focal plane after condenser lens A focusing；Photodetector A is installed in
The focal plane of the condenser lens A is used to detect the location information of hot spot；Diffracted beam g is focused by the condenser lens B
Hot spot to be detected is formed in focal plane afterwards；The focal plane that photodetector B is installed in the condenser lens B is used to detect light
The location information of spot；The photodetector A is connected with computer respectively with photodetector B.
The invention has the advantages that
(1), using one-dimensional plane transmission grating as Sensitive Apparatus, while being spread out using positive first-order diffraction light beam and negative one grade
Irradiating light beam realizes variate, eliminates the measurement error introduced due to light beam of light source drift, it is anti-interference to enhance measuring system
Ability, improve measurement accuracy.
(2), light beam to be measured passes through one-dimensional plane transmission grating twice, and first time diffracted beam is by being mutually perpendicular to
Polarization spectro microscope group after outgoing beam it is parallel with incident beam, this make outgoing beam again pass by transmission grating after go out
Irradiating light beam can be parallel with the collimated light beam after laser emitting, and can guarantee when beat and pitching occur for grating, should
Outgoing beam is still parallel with elementary beam；Therefore this characteristic of system can make rolling angle measurement completely not by deflection angle and
The influence of pitch angle improves rolling angle measurement precision；Simultaneously the device make originally there are the diffracted beams of the angle of diffraction to become
The light beam parallel with the collimated light beam after laser emitting is conducive to practical application so that probe unit is more compact.
(3) it since light beam to be measured passes through one-dimensional plane transmission grating twice, is acted on twice by grating, so that measurement system
Relative to the existing roll angle measurement method based on transmission grating, (Liu Xu, Kuang Cuifang, Wang Tingting wait to the measurement resolution of system
Roll angle measurement method based on common path parallel beams:, CN 101846506A [P] .2010.) in primary optics parameter phase
(screen periods, condenser lens focal length and detector resolving power are all identical), the measurement resolution of measuring system under conditions of
It is doubled.
Detailed description of the invention
High precision roll angle measuring device structural schematic diagram of the Fig. 1 based on transmission grating
Beam direction changes schematic diagram before and after the rolling of Fig. 2 grating
Light beam projects variation schematic diagram on grating before and after the rolling of Fig. 3 grating
Hot spot change in location schematic diagram on photodetector before and after the rolling of Fig. 4 grating
In figure piece number illustrate: 1, laser 2, collimation lens 3, one-dimensional plane transmission grating 4, polarization spectroscope A 5,
Polarization spectroscope B 6, condenser lens A 7, condenser lens B 8, photodetector A 9, photodetector B 10, computer
Specific embodiment
The present invention will be described in detail with specific embodiment with reference to the accompanying drawing.
High precision roll angle measurement method of the present invention based on transmission grating the following steps are included:
1., laser light source issue light beam collimated light beam is formed after collimator objective；
2., the collimated light beam after one-dimensional plane transmission grating, generate positive first-order diffraction light beam and negative first-order diffraction
Light beam is rigidly connected between the one-dimensional plane transmission grating and platform to be measured；
3., 2. described in positive first-order diffraction light beam and negative one grade diffracted beam by one group of diagonal line it is orthogonal partially
One group of outgoing beam parallel with positive first-order diffraction light beam and negative one grade diffracted beam is obtained after vibration light splitting microscope group；
4., 3. described in the outgoing beam parallel with positive and negative first-order diffraction light beam again pass by transmission grating, obtain one group
The diffracted beam parallel with optical axis；
5., 4. described in one group of diffracted beam parallel with optical axis formed after lens focus acts on two it is to be detected
Hot spot, while detecting using photodetector the location information of hot spot to be detected；
6., when platform to be measured occur rolling when, utilize photodetector detection 5. described in two hot spots to be detected
Change in location information, the change in location information of hot spot is sent into computer after signal processing circuit is handled, and calculating is rolled
The changing value of corner；
The roll angle γ of platform to be measured is obtained as follows:
In formula: Δ d+1For the position in measuring beam direction hot spot y on photodetector A in two neighboring sampling period
Difference；Δd-1For the alternate position spike in measuring beam direction hot spot y on photodetector B in two neighboring sampling period；F is to focus thoroughly
The focal length of mirror A and condenser lens B；Sin Ф is the wavelength of laser and the ratio of one-dimensional plane transmission grating grating constant.
The structure of High precision roll angle measuring device based on transmission grating is: laser 1, collimation lens 2, one-dimensional plane
Transmission grating 3 is arranged successively along the direction of propagation light a；3 transmission plane of one-dimensional plane transmission grating is vertical with incident beam；Institute
State polarization spectroscope A4, polarization spectroscope B5 is placed in the rear side of one-dimensional plane transmission grating 3, and polarization spectroscope A4, polarization spectro
Mirror B5 diagonal line is mutually perpendicular to, and is 45 ° with 1 optical axis included angle of laser；Positive first-order diffraction light beam b successively passes through polarization spectroscope
It is emitted after A4, polarization spectroscope B5 reflection, obtained outgoing beam e is parallel with positive first-order diffraction light beam b；Negative one grade diffracted beam
C is successively emitted after polarization spectroscope B5, polarization spectroscope A4, and obtained outgoing beam d and negative one grade diffracted beam c are flat
Row；The outgoing beam d and outgoing beam e again passes by one-dimensional plane transmission grating 3, obtains parallel with collimated light beam a
Diffracted beam f and diffracted beam g；Diffracted beam f forms hot spot to be detected in focal plane after condenser lens A6 focusing；Light
The focal plane that electric explorer A8 is installed in the condenser lens A6 is used to detect the location information of hot spot；Diffracted beam g warp
It crosses after the condenser lens B7 is focused and forms hot spot to be detected in focal plane；Photodetector B9 is installed in the condenser lens
The focal plane of B7 is used to detect the location information of hot spot；The photodetector A8 and photodetector B9 respectively with computer
10 are connected.
Illustrate the course of work of the High precision roll angle measuring device based on transmission grating below with reference to Fig. 1, Fig. 2 and Fig. 3:
Laser alignment light beam is propagated along Z axis, when one-dimensional plane transmission grating 3 is around the optical axis rotation angle γ, the diffraction light of measuring system
The beam direction of propagation changes, and diffracted beam f to be measured, diffracted beam g become diffracted beam f1, diffracted beam g1；Such as Fig. 3 institute
Show, when one-dimensional plane transmission grating 3 is around optical axis rotation, the company of diffracted beam f1 and diffracted beam g1 between the projection on grating
Line has rotated 2 γ angles relative to the line of diffracted beam f, diffracted beam g between the projection on grating, therefore relative to biography
System grating rotating angular measurement, rolling angle measurement resolving power of the invention are doubled.
When light source rotates γ angle there are angle drift, one-dimensional plane transmission grating 3, hot spot is upper in photodetector
It is as shown in Figure 4 to set variation.Hot spot A and hot spot B is respectively that photodetector A8 and photodetector B9 is received in the ideal situation
The initial position of the hot spot arrived, hot spot A1 and hot spot B1 are respectively that there are angle drift, one-dimensional plane transmission gratings 3 to rotate for light source
The position for the hot spot that photodetector A8 and photodetector B9 are received when γ angle；Hot spot A1 and hot spot A, hot spot B1 and light
Spot B is respectively as follows: in the alternate position spike of vertical direction
Δd+1=dγ+δ
Δd-1=-dγ+δ
In formula: dγPhotodetector A8 caused by γ angle and photodetector B9 are rotated for one-dimensional plane transmission grating 3
Facula position changing value；δ is that there are photodetector A8 caused by angle drift and photodetector B9 facula position to become for light source
Change value；
It is available by carrying out Difference Calculation to the received position difference signal of the photoelectric measuring device A and photoelectric measuring device B institute:
Δ d=Δ d+1-Δd-1=2dγ
It is available by calculating:
Therefore the measurement method eliminates laser light source angle drift pair while realizing High precision roll angle measurement
The influence of measurement result precision.
Claims (2)
1. a kind of High precision roll angle measurement method based on transmission grating, it is characterised in that: the described method comprises the following steps:
1., laser light source issue light beam collimated light beam is formed after collimator objective；
2., the collimated light beam after one-dimensional plane transmission grating, generate positive first-order diffraction light beam and negative one grade diffracted beam,
It is rigidly connected between the one-dimensional plane transmission grating and platform to be measured；
3., 2. described in positive first-order diffraction light beam and negative one grade diffracted beam by one group of diagonal line it is orthogonal polarization point
One group of outgoing beam parallel with positive first-order diffraction light beam and negative one grade diffracted beam is obtained after light microscopic group；
4., 3. described in the outgoing beam parallel with positive and negative first-order diffraction light beam again pass by transmission grating, obtain one group and light
The parallel diffracted beam of axis；
5., 4. described in one group of diffracted beam parallel with optical axis two light to be detected are formed after lens focus acts on
Spot, while detecting using photodetector the location information of hot spot to be detected；
6., when platform to be measured occur rolling when, utilize photodetector detection 5. described in two hot spots to be detected position
Change information is set, the change in location information of hot spot is sent into computer after signal processing circuit is handled, and calculates and obtains roll angle
Changing value；
The roll angle γ of platform to be measured is obtained as follows:
In formula: Δ d+1For the alternate position spike in measuring beam direction hot spot y on photodetector A in two neighboring sampling period；Δ
d-1For the alternate position spike in measuring beam direction hot spot y on photodetector B in two neighboring sampling period；F be condenser lens A and
The focal length of condenser lens B；Sin Ф is the wavelength of laser and the ratio of one-dimensional plane transmission grating grating constant.
2. a kind of High precision roll angle measuring device based on transmission grating, it is characterised in that: laser (1), collimation lens
(2), one-dimensional plane transmission grating (3) is arranged successively along the direction of propagation light a；One-dimensional plane transmission grating (3) transmission plane
It is vertical with incident beam；The polarization spectroscope A (4), polarization spectroscope B (5) are placed on rear side of one-dimensional plane transmission grating (3),
And polarization spectroscope A (4), polarization spectroscope B (5) diagonal line are mutually perpendicular to, and are 45 ° with laser (1) optical axis included angle；Positive one
Grade diffracted beam b is successively emitted after polarization spectroscope A (4), polarization spectroscope B (5) reflection, obtained outgoing beam e with
Positive first-order diffraction light beam b is parallel；Negative one grade diffracted beam c successively goes out after (4) by polarization spectroscope B (5), polarization spectroscope A
It penetrates, obtained outgoing beam d is parallel with negative one grade diffracted beam c；The outgoing beam d and outgoing beam e again passes by one
Dimensional plane transmission grating (3) obtains the diffracted beam f and diffracted beam g parallel with collimated light beam a；Diffracted beam f is by poly-
Hot spot to be detected is formed in focal plane after focus lens A (6) focusing；Photodetector A (8) is installed in the condenser lens A (6)
Focal plane be used to detect the location information of hot spot；Diffracted beam g is after the condenser lens B (7) focuses in focal plane
Form hot spot to be detected；The focal plane that photodetector B (9) is installed in the condenser lens B (7) is used to detect hot spot
Location information；The photodetector A (8) and photodetector B (9) respectively with computer (10).
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Cited By (1)
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| CN114705136A (en) * | 2022-03-15 | 2022-07-05 | 清华大学 | Auto-collimation absolute angle measurement method and system based on spectrum resolution technology |
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Application publication date: 20190308 |