Method and apparatus for multi-point distance measurement based on ring oblique incidence

Abstract

The present invention relates to a method and apparatus for multi-point distance measurement based on ring oblique incidence. The apparatus comprises: a standard lamp (2), a spectroradiometer (3), and a distance measurement assembly (5). The distance measurement assembly (5) is provided between the standard lamp (2) and the spectroradiometer (3). The distance measurement assembly (5) comprises: a diaphragm plate (502), which is arranged perpendicular to a connecting line between the center of the standard lamp (2) and the center of the spectroradiometer (3), a through hole (5021) being provided in the diaphragm plate (502), and the circle center of the through hole (5021) being located on the connecting line between the center of the standard lamp (2) and the center of the spectral radiometer (3); an annular movement mechanism (503), which is provided on the diaphragm plate (502) and is arranged concentric with the through hole (5021); and a laser measure (505), which is obliquely arranged on the annular movement mechanism (503). The annular movement mechanism (503) drives the laser measure (505) to move for multi-point measurement, and the standard deviation is calculated to determine whether the parallelism between the diaphragm plate (502) and the spectroradiometer (3) meets requirements. According to the present invention, annular movement and radial movement of the laser measure (505) are achieved by cooperation between a ring guide rail with a linear guide rail, multi-directional point measurement is achieved, and the parallelism between the diaphragm plate (502) and a detection ring reference surface (3011) is measured while the distance is measured.

Description

A method and device for multi-point ranging based on annular oblique incidence Technical Field

[0001] The present invention relates to the field of spectral radiation technology, and in particular to a method and device for multi-point ranging based on annular oblique incidence. Background Art

[0002] Referencing the example of uncertainty assessment for spectroradiometer measurements in Appendix A of JJF 1975-2022, "Spectroradiometer Calibration Specifications," the distance factor between the standard lamp and the spectroradiometer is one of seven independent uncertainty factors listed in this example. Measuring and adjusting the distance between the standard lamp and the spectroradiometer during calibration is a key component in the uncertainty assessment of spectroradiometer calibration.

[0003] Accurately measuring and adjusting the distance between a standard lamp and the instrument reference surface in the optical path of spectral radiometric calibration is a crucial step in uncertainty control. Currently, two main distance measurement methods exist during spectral radiometric calibration: mechanical rulers and laser rulers.

[0004] However, since there is usually no overlap between the reference surface of the standard lamp and the reference surface of the instrument receiving end, and the detection reference surface of the spectroradiometer is usually a narrow-band ring, this has some effects on the distance measurement, specifically:

[0005] 1. Mechanical ruler measurement requires extending the standard lamp reference surface and the instrument detection reference surface through rigid right-angle fittings so that the scale of the mechanical ruler can be visually read as close to the extended edges of the two reference surfaces as possible. This process will cause varying degrees of human error.

[0006] 2. There is usually no overlapping area between the reference plane of the standard lamp and the reference plane of the instrument receiving end, making bidirectional laser light source ranging less applicable. It is also necessary to extend the two reference planes to produce an overlapping area before bidirectional laser light source ranging can be used. This process still requires manual operation and has an impact.

[0007] 3. During the calibration measurement process, the stage typically features multi-dimensional adjustment capabilities, including rotation and pitch. The parallelism between the standard lamp reference plane and the instrument measurement reference plane is also a significant factor. When measuring these two parallel planes, parallelism measurements must be provided simultaneously as data for error assessment. Parallelism measurement requires distance measurement at multiple points on the plane, characterized by the discreteness of these multi-point distances. This significantly increases the complexity of the distance measurement process, leading to the default of not performing parallelism measurement in most cases.

[0008] To this end, we propose a method and device based on annular oblique incidence multi-point ranging.

[0009] Summary of the Invention

[0010] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides a method and device based on annular belt oblique incidence multi-point ranging, which realizes the circular movement and radial movement of the laser ruler by combining annular belt guide rails with linear guide rails. It can adapt to the measurement of detection ring reference surfaces of different diameters, realize the measurement of multi-directional points, and calculate the parallelism between the aperture plate and the detection ring reference surface while measuring the distance.

[0011] The technical solutions adopted in the present invention are as follows:

[0012] A multi-point distance measurement device based on annular oblique incidence, used in a spectral radiation calibration optical path, comprising:

[0013] Standard lamps, used to maintain and deliver spectral density of irradiance;

[0014] Spectroradiometer, used to measure spectral irradiance, spectral radiance, and relative spectral power distribution. The center of the standard lamp and the center of the spectroradiometer are on the same straight line;

[0015] The distance measuring component is set between the standard lamp and the spectroradiometer. The distance measuring component includes:

[0016] An aperture plate is arranged perpendicular to the line connecting the center of the standard lamp and the center of the spectroradiometer, and a through hole is opened on the aperture plate, the center of the through hole is located on the line connecting the center of the standard lamp and the center of the spectroradiometer;

[0017] The annular moving mechanism is arranged on the aperture plate and is concentric with the through hole;

[0018] The laser ruler is tilted and mounted on a circular moving mechanism. The circular moving mechanism drives the laser ruler to move for multi-point measurement. The standard deviation is calculated to determine whether the parallelism between the aperture plate and the spectroradiometer meets the requirements.

[0019] It is further characterized by:

[0020] It also includes a laser light source for generating a visible linear light beam and for indicating and ensuring that the standard lamp and the center of the receiving plane of the spectroradiometer are on the same straight line.

[0021] The laser light source is mounted on the base via a first bracket, the standard lamp is mounted on the base via a second bracket, and the spectroradiometer is mounted on the adjustment table. The spectroradiometer and the standard lamp can be fine-tuned.

[0022] The spectroradiometer is provided with a detection ring, the detection ring is provided with a detection ring reference surface, and the laser ruler is irradiated on the detection ring reference surface.

[0023] The aperture plate is mounted on the base through a third bracket. The annular moving mechanism includes an annular track and a first moving block. The first moving block is slidably arranged on the annular track and is driven by a driving mechanism.

[0024] The laser ruler is installed on the annular moving mechanism through a linear moving mechanism. The linear moving mechanism includes a linear track and a second moving block. The second moving block is slidably set on the linear track. The second moving block is driven by a driving mechanism, and the laser ruler is tilted on the second moving block.

[0025] The present invention also discloses a method for multi-point ranging based on annular oblique incidence, comprising the following steps:

[0026] Step a: Place the standard plate at a predetermined position in front of the laser encoder. The distance from the center of the standard lamp to the reference plane of the standard plate is a known value, dt1. Read the oblique incident distance dc1 measured by the laser encoder at this time.

[0027] Step b: Place the standard plate in front of the laser encoder at the second set position. The distance from the center of the standard lamp to the reference plane of the standard plate is a known quantity, dt2. Read the oblique incidence distance dc2 measured by the laser encoder at this time.

[0028] Step c, bring dt1, dc1, dt2, dc2 into

[0029] dt=ds+dc·sinθ (5), we get

[0030] dt1=ds+dc1·sinθ(vi);

[0031] dt2=ds+dc2·sinθ (VII);

[0032] Solved

[0033] Where: dt is the distance from the center of the standard lamp to the reference plane of the detection ring of the spectroradiometer;

[0034] ds is the distance from the center of the standard lamp to the laser encoder emission point;

[0035] dc is the distance measured by the laser encoder at oblique incidence;

[0036] θ is the angle between the oblique incident laser scale and the aperture plate;

[0037] In step d, sinθ and ds are substituted into equation (5) as known numbers, and the dt value is calculated by measuring dc and substituting it into equation (5).

[0038] It is further characterized by:

[0039] When measuring dc1 in step a and dc2 in step b, the first moving block drives the laser ruler to move to N positions along the circular track through the linear moving mechanism to measure point by point, and then

[0040] Where: d i is the measured distance value of the i-th position;

[0041] N is the number of measurement locations;

[0042] is the average of the distances measured at N locations;

[0043] Get the mean respectively As a measured value.

[0044] According to the standard deviation formula:

[0045] Where: D is a set of N position measurement distances, D = {d1, d2, ..., dN};

[0046] d i is the measured distance value of the i-th position;

[0047] N is the number of measurement locations;

[0048] is the average of the distances measured at N locations;

[0049] The standard deviation is calculated to determine whether the parallelism meets the requirements.

[0050] The linear motion mechanism can drive the laser ruler to move in the radial direction, so as to adapt to detection ring reference surfaces of different diameters for measurement.

[0051] The beneficial effects of the present invention are as follows:

[0052] The present invention has a compact and reasonable structure and is easy to operate. It realizes the annular and radial movement of the laser ruler by combining an annular guide rail with a linear guide rail. It can adapt to measuring detection ring reference surfaces of different diameters, realize the measurement of multiple points, and calculate the parallelism between the aperture plate and the detection ring reference surface while measuring the distance.

[0053] At the same time, the present invention also has the following advantages:

[0054] (1) Using oblique incidence distance measurement instead of vertical distance measurement and then converting it into vertical distance using trigonometric function relationship can effectively solve the plane spacing problem in non-overlapping areas.

[0055] (2) The laser ruler oblique-incidence distance measurement device of the present invention requires only a single mechanical ruler measurement process, involving a certain degree of manual intervention, during the calibration of the optical path system's geometric parameters ds and sinθ for spectral radiation calibration. The measurement of dt in subsequent tests and calibrations can be automated, effectively eliminating the impact of manual operation.

[0056] (3) On the basis of the annular guide rail, a linear slide rail is stacked. In addition to the annular sliding, the laser ruler can also slide radially, and can be adapted to the receiving annular reference planes of different diameters of the spectral radiation instrument.

[0057] (4) By placing the standard plate on two calibrated displacements, the values ​​of ds and sinθ can be obtained. After the system is calibrated, workers no longer need to manually measure the values. They only need to install the spectroradiometer 3 and then measure dc through the laser ruler 505. The value of dt can be calculated according to equation (5); the error caused by manual measurement is avoided, and the measurement accuracy is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] FIG1 is a schematic diagram of the correspondence between the sides and angles of the trigonometric functions of a right triangle according to the present invention.

[0059] FIG2 is a schematic diagram of the oblique incidence effect of the laser ruler ring zone distribution of the present invention.

[0060] FIG3 is a schematic diagram showing the effect of the laser ruler measuring and detecting annular surfaces of the present invention.

[0061] FIG4 is a schematic diagram of the optical path effect of the spectral radiation calibration of the present invention.

[0062] FIG5 is a schematic diagram of a spectroradiometer according to the present invention.

[0063] FIG6 is a schematic diagram showing the geometric relationship of the optical path of the spectral radiation calibration of the present invention.

[0064] FIG7 is a schematic diagram showing the geometric relationship of the spectral radiation calibration optical path when the standard plate of the present invention is in position one.

[0065] FIG8 is a schematic diagram showing the geometric relationship of the optical path for spectral radiation calibration when the standard plate of the present invention is in position two.

[0066] Among them: 1. Laser light source; 101. First bracket; 2. Standard lamp; 201. Second bracket; 3. Spectroradiometer; 301. Detection ring; 3011. Detection ring reference surface; 4. Base; 5. Distance measurement component; 501. Third bracket; 502. Aperture plate; 5021. Through hole; 503. Annular moving mechanism; 5031. Annular track; 5032. First moving block; 504. Linear moving mechanism; 5041. Linear track; 5042. Second moving block; 505. Laser ruler; 6. Standard flat plate. DETAILED DESCRIPTION

[0067] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0068] Example 1

[0069] As shown in Figures 1 to 6, a multi-point ranging device based on annular oblique incidence includes a standard lamp 2 and a spectroradiometer 3. The standard lamp 2 is mounted on a base 4 via a second bracket 201, and the spectroradiometer 3 is mounted on an adjustment table. The device also includes a laser light source 1 for generating a visible linear light beam and for indicating and ensuring that the centers of the receiving planes of the standard lamp 2 and the spectroradiometer 3 are on the same straight line. The laser light source 1 is mounted on the base 4 via a first bracket 101. The standard lamp 2 is a standard measuring instrument for maintaining and transmitting the spectral intensity of irradiance. The spectroradiometer 3 is an optical instrument for measuring spectral irradiance, spectral radiance brightness or relative spectral power distribution.

[0070] The spectroradiometer 3 is provided with a detection ring 301 , and the detection ring 301 is provided with a detection ring reference surface 3011 . The laser ruler 505 is irradiated on the detection ring reference surface 3011 .

[0071] As shown in Figures 2-4, a distance measuring assembly 5 is disposed between the standard lamp 2 and the spectroradiometer 3. This assembly comprises a third bracket 501, an aperture plate 502, a circular motion mechanism 503, a linear motion mechanism 504, and a laser ruler 505. The aperture plate 502 is mounted on the base 4 via the third bracket 501. A through-hole 5021 is defined in the aperture plate 502, through which the standard lamp 2 illuminates the spectroradiometer 3. The center of the through-hole 5021 is aligned with the center of the laser light source 1, the center of the standard lamp 2, and the center of the spectroradiometer 3. The aperture plate 502 is perpendicular to the line connecting the center of the standard lamp 2 and the center of the spectroradiometer 3.

[0072] The linear motion mechanism 504 includes a linear track 5041 and a second moving block 5042. The second moving block 5042 is slidably mounted on the linear track 5041 and driven by a driving mechanism. The driving mechanism drives the second moving block 5042 to move on the linear track 5041. The laser scale 505 is tilted and fixed to the second moving block 5042. The second moving block 5042 can drive the laser scale 505 to move in the radial direction.

[0073] The annular moving mechanism 503 includes an annular track 5031 and a first moving block 5032. The first moving block 5032 is slidably set on the annular track 5031. The first moving block 5032 is driven by a driving mechanism. The driving mechanism drives the first moving block 5032 to move on the annular track 5031. The annular track 5031 is set on the aperture plate 502 and is located on the outside of the through hole 5021. The annular track 5031 and the through hole 5021 are concentric.

[0074] The linear track 5041 is provided on the first moving block 5032 , and the first moving block 5032 drives the laser ruler 505 to move along the circular track 5031 through the linear moving mechanism 504 .

[0075] As shown in Figure 1, the laser encoder 505 uses oblique incidence to measure distance, and then uses the ratio of the opposite side to the hypotenuse of the trigonometric function to indirectly measure the distance;

[0076] Assume that point A is the incident point of the laser scale 505, point B is the point where the laser light source illuminates the detection ring reference surface 3011, and the actual measured slant distance is c. The vertical distance a can be indirectly calculated. According to the trigonometric function relationship:

[0077] sin(A)=a / c

[0078] Then there is

[0079] a=c·sin(A) (II)

[0080] As shown in FIG. 2 and FIG. 3 , the second moving block 5042 can drive the laser ruler 505 to move in the radial direction so as to adapt to measurement of detection ring reference surfaces 3011 of different diameters.

[0081] The first moving block 5032 drives the laser ruler 505 to move to N positions along the circular track 5031 through the linear moving mechanism 504 to perform point-by-point measurement. The measurement positions can be evenly distributed and spaced at fixed angles.

[0082] The distance measurements at multiple locations can be used to calculate the parallelism between aperture plate 502 and detection ring reference surface 3011. The standard deviation of these distance measurements can be used to characterize the parallelism. For example, the standard deviation of the multi-point distances can be set to no more than 0.5 mm. The standard deviation is represented by formula (3), and the average value is represented by formula (4).

[0083] in

[0084] D is a set of N position measurement distances, D = {d1, d2, ..., dN};

[0085] d i is the measured distance value of the i-th position;

[0086] N is the number of measurement locations;

[0087] is the average of the distances measured at N locations;

[0088] Since the distance d i Related to the azimuth angle, if the parallelism does not meet the requirements, the spectroradiometer 3 or the standard lamp 2 can be fine-tuned according to the azimuth relationship, and then measurements are taken at multiple positions to calculate whether the parallelism meets the requirements. Repeat the above operation until the parallelism meets the measurement requirements and then measure the plane spacing.

[0089] Example 2

[0090] As shown in Figure 5, the relationship between the geometric quantities in the system is shown in Equation (5).

[0091] dt=ds+dc·sinθ (V)

[0092] in

[0093] dt is the distance from the center of the standard lamp 2 to the detection ring reference surface 3011 of the spectroradiometer 3;

[0094] ds is the distance from the center of the standard lamp 2 to the emission point of the laser encoder 505;

[0095] dc is the distance measured by the laser encoder 505 at oblique incidence;

[0096] da is the horizontal distance from the laser ruler 505 emission point to the reference surface 3011 of the detection ring of the spectroradiometer 3;

[0097] db is the vertical distance from the laser ruler 505 emission point to the reference surface 3011 of the detection ring of the spectroradiometer 3;

[0098] θ is the angle between the oblique incidence laser scale 505 and the aperture plate 502;

[0099] dc and da conform to the sinusoidal relationship of trigonometric functions.

[0100] A multi-point ranging method based on annular oblique incidence includes the following steps:

[0101] Place the standard plate 6 at a predetermined position in front of the laser encoder 505. The distance from the center of the standard lamp 2 to the reference plane of the standard plate 6 is dt1, which is a known quantity set in advance.

[0102] Adjust the standard plate 6 to the second position set in front of the laser ruler 505. At this time, the distance from the center of the standard lamp 2 to the reference plane of the standard plate 6 is dt2, which is set in advance as a known quantity.

[0103] The first moving block 5032 drives the laser ruler 505 to move to N positions along the circular track 5031 through the linear moving mechanism 504 to perform point-by-point measurement, and respectively obtains the multi-point average of the standard plate 6 at displacement 1 and position 2 as the measurement values ​​of dc1 and dc2;

[0104] Through the calibration test process using the standard plate 6 at two different positions, the corresponding dt1, dc1, dt2, and dc2 are substituted into equation (5) to obtain two calibration equations:

[0105] dt1=ds+dc1·sinθ (vi)

[0106] dt2=ds+dc2·sinθ (VII)

[0107] The values ​​of the system geometric parameters ds and sinθ are thus obtained, as shown in Equation (8) and Equation (9).

[0108] After calibration and measurement, ds and sinθ can be used as known geometric parameters of the system for subsequent calibration tests of spectral radiation instruments.

[0109] After the system is calibrated, it is only necessary to measure dc using the laser encoder 505, and the corresponding dt value can be calculated according to equation (5).

[0110] The corresponding dc1 and dc2 are measured at position 1 and position 2 by the standard plate 6. The dt1 and dt2 at position 1 and position 2 are the values ​​set when setting displacement 1 and position 2. In this way, there is no need to measure dt1 and dt2 separately when placing the standard plate 6, which reduces the possible error caused by the measurement.

[0111] And after determining ds and sinθ, we only need to measure the value of dc to calculate the value of dt according to equation (5);

[0112] After the system is calibrated, workers no longer need to manually measure values. They only need to install the spectroradiometer 3 and then measure dc using the laser ruler 505. The value of dt can be calculated according to equation (5). This avoids errors caused by manual measurement and ensures accurate measurement.

[0113] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. A multi-point distance measurement device based on annular oblique incidence, used in the spectral radiation calibration optical path, characterized in that: include: Standard lamps (2) for maintaining and delivering the spectral intensity of irradiance; A spectroradiometer (3) is used to measure spectral radiance, spectral radiance, and relative spectral power distribution, wherein the center of the standard lamp (2) and the center of the spectroradiometer (3) are on the same straight line; The distance measuring component (5) is arranged between the standard lamp (2) and the spectroradiometer (3), and the distance measuring component (5) comprises: An aperture plate (502) is arranged perpendicular to a line connecting the center of the standard lamp (2) and the center of the spectroradiometer (3); a through hole (5021) is provided on the aperture plate (502), and the center of the through hole (5021) is located on a line connecting the center of the standard lamp (2) and the center of the spectroradiometer (3); An annular moving mechanism (503) is arranged on the aperture plate (502) and is arranged concentrically with the through hole (5021); The laser ruler (505) is tiltedly arranged on the annular moving mechanism (503), and the annular moving mechanism (503) drives the laser ruler (505) to move to perform multi-point measurement, and the standard deviation is calculated to determine whether the parallelism between the aperture plate (502) and the spectroradiometer (3) meets the requirements.

2. A multi-point ranging device based on annular zone oblique incidence as claimed in claim 1, characterized in that: It also includes a laser light source (1) for generating a visible linear light beam and for indicating and ensuring that the center of the standard lamp (2) and the receiving plane of the spectroradiometer (3) are on the same straight line.

3. A multi-point ranging device based on annular zone oblique incidence as claimed in claim 2, characterized in that: The laser light source (1) is mounted on a base (4) via a first bracket (101), the standard lamp (2) is mounted on the base (4) via a second bracket (201), the spectroradiometer (3) is mounted on an adjustment table, and the spectroradiometer (3) and the standard lamp (2) can be fine-tuned.

4. The multi-point ranging device based on annular zone oblique incidence as claimed in claim 1, characterized in that: The spectroradiometer (3) is provided with a detection ring (301), the detection ring (301) is provided with a detection ring reference surface (3011), and the laser ruler (505) irradiates the detection ring reference surface (3011).

5. The multi-point ranging device based on annular zone oblique incidence as claimed in claim 3, characterized in that: The aperture plate (502) is mounted on the base (4) via a third bracket (501); the annular moving mechanism (503) comprises an annular track (5031) and a first moving block (5032); the first moving block (5032) is slidably arranged on the annular track (5031); and the first moving block (5032) is driven by a driving mechanism.

6. The multi-point distance measurement device based on annular zone oblique incidence as claimed in claim 5, characterized in that: The laser ruler (505) is installed on the annular moving mechanism (503) via a linear moving mechanism (504); the linear moving mechanism (504) comprises a linear track (5041) and a second moving block (5042); the second moving block (5042) is slidably arranged on the linear track (5041); the second moving block (5042) is driven by a driving mechanism; and the laser ruler (505) is tiltedly arranged on the second moving block (5042).

7. A method for multi-point ranging based on annular oblique incidence, characterized in that: The steps include: Step a, placing the standard plate (6) at a set position in front of the laser ruler (505), at which time the distance from the center of the standard lamp (2) to the reference surface of the standard plate (6) is a known quantity dt1; reading the oblique incident measurement distance dc1 of the laser ruler (505) at this time; Step b, placing the standard plate (6) at the second set position in front of the laser ruler (505), at which time the distance from the center of the standard lamp (2) to the reference surface of the standard plate (6) is a known quantity dt2; reading the oblique incident measurement distance dc2 of the laser ruler (505) at this time; Step c, bring in dt1, dc1, dt2, dc2 dt=ds+dc·sinθ (V), we get dt1=ds+dc1·sinθ(vi); dt2=ds+dc2·sinθ (VII); Solved Where: dt is the distance from the center of the standard lamp (2) to the detection ring reference surface (3011) of the spectroradiometer (3); ds is the distance from the center of the standard lamp (2) to the emission point of the laser ruler (505); dc is the oblique incidence measurement distance of the laser ruler (505); θ is the angle between the oblique incidence of the laser ruler (505) and the aperture plate (502); In step d, sinθ and ds are substituted into equation (5) as known numbers, and the dt value is calculated by measuring dc and substituting it into equation (5).

8. The method for multi-point ranging based on annular oblique incidence as claimed in claim 7, characterized in that: When measuring dc1 in step a and dc2 in step b, the first moving block (5032) drives the laser ruler (505) to move to N positions along the circular track (5031) through the linear moving mechanism (504) to measure point by point, and then Where: d i is the measured distance value of the i-th position; N is the number of measurement locations; is the average of the distances measured at N locations; Get the mean value as a measured value.

9. The method for multi-point ranging based on annular zone oblique incidence as claimed in claim 8, characterized in that: According to the standard deviation formula: Where: D is a set of N position measurement distances, D = {d1, d2, ..., dN}; d i is the measured distance value of the i-th position; N is the number of measurement locations; is the average of the distances measured at N locations; The standard deviation is calculated to determine whether the parallelism meets the requirements.

10. The method for multi-point ranging based on annular zone oblique incidence as claimed in claim 8, characterized in that: The linear motion mechanism (504) can drive the laser ruler (505) to move in the radial direction, and is used to adapt to detection ring reference surfaces (3011) of different diameters for measurement.

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