CN110375708B - Three-dimensional angle measurement system - Google Patents

Abstract

The three-dimensional angle measurement system provided by the present invention includes: a measurement end and a target end, the target end includes a right angle prism, and the measurement end includes a white light source, a condenser, a reticle, a first beam splitting prism, a second beam splitting prism, a A narrow-band filter, a second narrow-band filter, a collimating objective lens, a first area array detector and a second area array detector, the present invention utilizes different reflective surfaces of the right angle prism, and the inclined surface represents the azimuth and elevation angle changes, and the two The right-angle surface represents the change of the roll angle, and can realize the simultaneous measurement of three-dimensional angles. It has high angle measurement accuracy, simple and compact structure, low cost, maintenance-free, and convenient use. The system has good engineering application prospects.

Description

A three-dimensional angle measurement system

technical field

The invention relates to the technical field of modern high-precision measurement, in particular to a three-dimensional angle measurement system.

Background technique

Angle is a unit used to measure angle, and angle measurement is an important part of geometric measurement. With the development of production and high technology, the requirements for angle measurement are increasing day by day, and the angle measurement technology and its measurement accuracy are also constantly improving. At present, the angle measurement methods are mainly divided into mechanical measurement, electronic measurement, electromagnetic measurement and photoelectric measurement. Among them, photoelectric measurement converts optical signal into electrical signal, receives information through computer and performs data processing to complete online and automatic measurement. This method has the characteristics of non-contact, high accuracy and high sensitivity. In addition, the development of stable laser light sources has made industrial field measurement possible, so the application of photoelectric goniometer has become more and more widely, and it has become one of the main means of modern high-precision measurement.

In engineering applications, the spatial positions of some precision measuring equipment or reference equipment are different, and it is impossible to connect these equipment to be an absolute rigid body. Even if the coordinate reference can be matched to a certain accuracy during manufacturing, in practical applications, the environment Instability and human factors can cause structural deformation, and there are small angular changes in three dimensions between devices. Taking the space survey ship as an example, the main optical measurement equipment, radar, etc., all need to use the geodetic coordinates of the true north of the inertial navigation platform as the benchmark. When working at sea, due to the existence of external disturbances (such as wind and waves, temperature, time, etc. aging, etc.), the hull will have three-dimensional deformation angles (longitudinal deflection, lateral deflection, torsion angle). These three deformation angles cause measurement errors when the measurement equipment directly uses the reference output from the inertial navigation system. In order to correct the error and obtain accurate measurement results, it is necessary to measure the three-dimensional angular deformation of the hull in real time.

Autocollimator is a general-purpose angle measuring instrument with simple system, high measurement accuracy and mature technology. It is widely used in various industrial sectors and scientific research. However, the autocollimator can only obtain the azimuth and pitch angles, and cannot realize the measurement of the torsion angle. Therefore, how to measure the torsion angle with high precision and realize the simultaneous measurement of the three-dimensional deformation angle is a focus. At present, there are many methods for twist angle measurement at home and abroad, which can be classified into several categories such as interferometry, polarization method and geometrical optics method.

In the current engineering application, the representative solution for measuring the relative deformation angle between multiple bases on a straight line is the hull deformation measurement system on the aerospace survey ship, which realizes the measurement of the azimuth and pitch angle through the collimation method, and uses the large steel pipe method. The measurement of the lateral torsion angle is realized. This method has high measurement accuracy, but the system is complex, takes up a lot of space, and brings a lot of inconvenience to installation and maintenance, so it does not have a general application type. However, there is no mature solution for the three-dimensional attitude angle simultaneous measurement system of two bases.

SUMMARY OF THE INVENTION

In view of this, it is necessary to provide a three-dimensional angle measurement system with high angle measurement accuracy and simple and compact structure, aiming at the defects of the prior art.

To achieve the above object, the present invention adopts the following technical solutions:

A three-dimensional angle measurement system, comprising: a measurement end and a target end, the target end includes a right angle prism, the measurement end includes a white light source, a condenser, a reticle, a first beam splitting prism, a second beam splitting prism, a first narrow band A filter, a second narrow-band filter, a collimating objective lens, a first area array detector, and a second area array detector; The red light in the wavelength band is transmitted, and the second area array detector only allows the incident red light to pass through, wherein:

The light emitted by the white light source illuminates the reticle located on the focal plane of the condenser lens, and then becomes a parallel beam after being collimated by the collimating objective lens, and the parallel beam is incident on the slope of the right angle prism:

The short-wavelength green light is reflected by the inclined surface of the right angle prism, and then passes through the collimating objective lens, the first beam splitting prism and the first narrow-band filter in sequence, and then is transmitted to the first area array detector by the first area array detector. Receive and perform subsequent image processing, and obtain the corresponding azimuth and pitch angle information through the displacement change of the reticle image;

The long-wavelength red light transmits the inclined surface of the right angle prism, is reflected by the two right angle surfaces of the right angle prism, and then passes through the collimating objective lens, the first beam splitting prism, the second beam splitting prism and the The second narrow-band filter is then received by the second area array CCD and subjected to subsequent image processing. When the right-angle prism rotates around the z-axis of the optical axis, the reflected light is caused to rotate, so that the beam splits The image of the plate is rotated around the x-axis, resulting in a change in slope on the second area array detector to establish a quantitative relationship between the angle of rotation of the right angle prism around the optical axis and the change in the slope of the above-mentioned reticle image to obtain roll horn.

In some preferred embodiments, the measurement end and the target end are placed on the first base and the second base, respectively.

In some preferred embodiments, the white light source is an LED white light source.

In some preferred embodiments, the oblique surface of the right angle prism is coated with an optical film in sub-wavelength bands, the average transmittance at wavelengths 620-800 nm reaches 90%, and the average reflectivity at wavelengths 470-590 nm reaches 95%.

In some preferred embodiments, the optical film can make the average transmittance of wavelengths 620-800nm reach above 90%, and the average reflectivity of wavelengths 470-590nm can reach above 95%.

In some preferred embodiments, the center wavelength of the first narrow-band filter is 532 nm, and the center wavelength of the second narrow-band filter is 632.8 nm.

In some preferred embodiments, the reticle is a cross reticle.

The advantages of the present invention adopting the above technical solutions are:

The three-dimensional angle measurement system provided by the present invention includes a measurement end and a target end, the target end includes a right angle prism, and the measurement end includes a white light source, a condenser, a reticle, a first beam splitting prism, a second beam splitting prism, a first A narrow-band filter, a second narrow-band filter, a collimating objective lens, a first area array detector and a second area array detector, the light emitted by the white light source illuminates the reticle located on the focal plane of the condenser lens, After being collimated by the collimating objective lens, it becomes a parallel beam, and the parallel beam is incident on the slope of the right-angle prism: the green light in the short wavelength band is reflected by the slope of the right-angle prism, and then passes through the collimating objective lens, the The first dichroic prism and the first narrow-band filter are received by the first area array detector and subjected to subsequent image processing, and the corresponding azimuth and elevation angles are obtained through the displacement change of the reticle image. information; long-wavelength red light transmits the inclined surface of the right angle prism, is reflected by the two right angle surfaces of the right angle prism, and then passes through the collimating objective lens, the first beam splitting prism, the second beam splitting prism and the The second narrow-band filter is then received by the second area array CCD and subjected to subsequent image processing. When the right-angle prism rotates around the z-axis of the optical axis, the reflected light is caused to rotate, so that the beam splits The image of the plate is rotated around the x-axis, resulting in a change in slope on the second area array detector to establish a quantitative relationship between the angle of rotation of the right angle prism around the optical axis and the change in the slope of the above-mentioned reticle image to obtain roll The three-dimensional angle measurement system provided by the present invention utilizes different reflective surfaces of the right-angle prism, the inclined surface represents the change of the azimuth and the pitch angle, and the two right-angle surfaces (ie, the ridge line) represent the change of the roll angle, which can realize the simultaneous measurement of three-dimensional angles, and has the advantages of relatively High angle measurement accuracy, simple and compact structure, low cost, maintenance-free, easy to use, the system has good engineering application prospects.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic perspective view of a three-dimensional angle measurement system provided by an embodiment of the present invention;

2 is a schematic structural diagram of a three-dimensional angle measurement system provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of displacement and slope changes of a cross reticle image provided by an exemplary embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Please refer to FIG. 1 and FIG. 2 , which are schematic structural diagrams of a three-dimensional angle measurement system according to an embodiment of the present invention, including a measurement end 110 and a target end 120 .

In some preferred embodiments, the measurement end 110 and the target end 120 are respectively placed on the first base A and the second base B, and can measure the three-dimensional attitude angle of the base 2 corresponding to the base 1 .

Specifically, a three-dimensional attitude angle measurement coordinate system F is established, wherein x and z constitute a horizontal reference plane, the z-axis is the optical axis, and the coordinate system F is a right-hand coordinate system.

Please refer to FIG. 2 again, the measuring end 110 includes a white light source 111 , a condenser 112 , a reticle 113 , a first beam splitter 114 , a second beam splitter 115 , a first narrowband filter 116 , and a second narrowband filter 117. The collimating objective lens 118, the first area array detector 119 and the second area array detector 210; the target end 120 includes a right angle prism 121, the slope of the right angle prism 121 reflects the incident short-wavelength green light Moreover, the incident long-wavelength red light is transmitted, and the second area array detector 210 only allows the incident red light to pass therethrough.

The three-dimensional angle measurement system provided by the present invention works as follows:

The light emitted by the white light source 111 illuminates the reticle 113 located on the focal plane of the condenser lens 112 , and is then collimated by the collimating objective lens 118 to become a parallel beam, and the parallel beam is incident on the slope of the right angle prism 121 . :

The short-wavelength green light is reflected by the inclined surface of the right-angle prism 121 and then passed through the collimating objective lens 118 , the first beam splitting prism 114 and the first narrow-band filter 116 in sequence, and then is passed through the first narrow-band filter 116 . The area array detector 119 receives and performs subsequent image processing, and obtains the corresponding azimuth and pitch angle information through the displacement change of the reticle 113 image.

The long-wavelength red light transmits the inclined surface of the right-angle prism 121, is reflected by the two right-angle surfaces of the right-angle prism 121, and then passes through the collimating objective lens 118, the first beam splitting prism 114, the second The dichroic prism 115 and the second narrow-band filter 117 are then received by the second area array detector 210 and subjected to subsequent image processing. When the right-angle prism 121 rotates around the optical axis z, it causes reflection The rotation of the light rays causes the image of the beam splitter to rotate around the x-axis, resulting in a change in slope on the second area array detector 210 to establish the angle of rotation of the right angle prism 121 around the optical axis and the above-mentioned reticle 113 The roll angle is obtained as a quantitative relationship between changes in the slope of the image.

In some preferred embodiments, the white light source 111 is an LED white light source.

In some preferred embodiments, the oblique sub-bands of the right angle prism 121 are coated with an optical film, the average transmittance at wavelengths 620-800 nm reaches 90%, and the average reflectivity at wavelengths 470-590 nm reaches 95%.

In some preferred embodiments, the optical film can make the average transmittance of wavelengths 620-800nm reach above 90%, and the average reflectivity of wavelengths 470-590nm can reach above 95%.

In some preferred embodiments, the center wavelength of the first narrow-band filter is 532 nm, and the center wavelength of the second narrow-band filter is 632.8 nm.

It can be understood that in the present invention, the azimuth, pitch angle measurement and roll angle measurement can be distinguished by using optical film coating on the sub-wavelength band of the inclined plane of the right angle prism 121 and using a narrow-band filter.

In some preferred embodiments, the reticle is a cross reticle, and the change of the center point can be used to calculate the azimuth and pitch angle, thus overcoming the possibility that the slit displacement change may not be obtained by using a slit reticle. Defects.

Please refer to FIG. 3 , which is a schematic diagram of displacement and slope change of a cross reticle image provided by an embodiment of the present invention. It can be understood that the change of the center point of the cross reticle can be used to calculate the azimuth and pitch angle.

The three-dimensional angle measurement system provided by the present invention utilizes different reflective surfaces of the right-angle prism, the inclined surface represents the change of the azimuth and the pitch angle, and the two right-angle surfaces (that is, the ridge line) represent the change of the roll angle, which can realize the simultaneous measurement of the three-dimensional angle, and has a relatively high Angle measurement accuracy, simple and compact structure, low cost, maintenance-free, easy to use, the system has good engineering application prospects.

Of course, the three-dimensional angle measurement system of the present invention can also have various transformations and modifications, and is not limited to the specific structure of the above-mentioned embodiments. In a word, the protection scope of the present invention should include those changes or substitutions and modifications that are obvious to those of ordinary skill in the art.

Claims (6)

1. A three-dimensional angle measurement system, comprising: the device comprises a measuring end and a target end, wherein the target end comprises a right-angle prism, and the measuring end comprises a white light source, a condenser lens, a reticle, a first beam splitter prism, a second beam splitter prism, a first narrow-band optical filter, a second narrow-band optical filter, a collimating objective, a first area array detector and a second area array detector; the inclined plane of the right-angle prism reflects incident green light of a short wave band and transmits incident red light of a long wave band, and the second planar array detector only allows the incident red light to penetrate through, wherein:

the light emitted by the white light source illuminates a reticle positioned on the focal plane of the condensing lens, and is collimated by the collimating objective lens to form parallel beams, and the parallel beams enter the inclined plane of the right-angle prism:

the short-waveband green light is reflected by the inclined plane of the right-angle prism, then sequentially passes through the collimating objective, the first light splitting prism and the first narrow-band filter, is received by the first area array detector, and is subjected to subsequent image processing, and the information of the corresponding azimuth and pitch angle is obtained through the displacement change of the reticle image;

the red light of the long wave band transmits the inclined plane of the right-angle prism, is reflected by two right-angle surfaces of the right-angle prism, then sequentially passes through the collimating objective lens, the first light splitting prism, the second light splitting prism and the second narrow-band filter, is received by the second planar array CCD and is subjected to subsequent image processing, when the right-angle prism rotates around an optical axis z axis, reflected light is caused to rotate, so that an image of the light splitting plate rotates around an x axis, the slope on the second planar array detector is changed, and the quantitative relation between the rotation angle of the right-angle prism around the optical axis and the slope change of the image of the light splitting plate is established to obtain the roll angle.

2. The three-dimensional angle measurement system of claim 1, wherein the measurement end and the target end are disposed on a first base and a second base, respectively.

3. The three-dimensional angle measurement system of claim 1, wherein the white light source is an LED white light source.

4. The three-dimensional angle measuring system of claim 1, wherein the oblique surface of the rectangular prism is coated with an optical film in a sub-band, the average transmittance at wavelength 620 and 800nm is 90%, and the average reflectance at wavelength 470 and 590nm is 95%.

5. The three-dimensional angle measurement system of claim 1, wherein the first narrowband filter has a center wavelength of 532nm and the second narrowband filter has a center wavelength of 632.8 nm.

6. The three-dimensional angle measurement system of claim 5, wherein the reticle is a cross reticle.

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