Method for calibrating coordinates of large-size reference point group based on station transfer interference intersection ranging

Abstract

The application belongs to the technical field of aircraft assembly measurement, and particularly relates to a large-size reference point group coordinate calibration method based on station conversion interference intersection ranging, which is based on the measurement of reference point group coordinates by interference intersection ranging, and based on the station conversion measurement method of point group classification, group collection according to the type, and fusion between groups, so as to realize the measurement and calibration of reference point group coordinates, solve the calibration problem of point position coordinates that is difficult to be obtained by direct interference intersection ranging under the condition of light path obstacles existing in the large-size aircraft assembly site, realize the high-precision, low-cost and high-efficiency calibration of reference point group coordinates, and support the construction of an aircraft intelligent assembly coordinate system.

Description

Technical Field

[0001] This application belongs to the field of aircraft assembly measurement technology, specifically involving a method for calibrating the coordinates of a large-size reference point group based on interferometric intersection ranging. Background Technology

[0002] Establishing and calibrating a high-precision assembly coordinate system is the prerequisite and foundation for intelligent aircraft assembly, and also the key to verifying the quality of intelligent aircraft assembly. The markers of the intelligent aircraft assembly coordinate system are a group of reference points, usually fixed on a rigid foundation at the aircraft assembly station. Calibration is typically achieved by measuring the coordinates of each reference point relative to the laser tracker's coordinate system using a laser tracker, followed by coordinate transformation. The higher the coordinate accuracy of the calibrated reference point group, the higher the measurement accuracy of the points to be measured in the intelligent aircraft assembly, and ultimately, the higher the overall assembly accuracy.

[0003] Generally, the coordinate accuracy of reference points in the coordinate system of modern large aircraft assembly is required to be controlled within 0.12mm / 50m or 0.20mm / 100m. Currently, the most advanced laser tracker, Laica AT960-LR, has a three-dimensional coordinate measurement accuracy of 0.015mm + 0.006mm / m×L. When the aircraft assembly dimensions are less than 25m, its measurement accuracy can reach 0.09mm, and the measurement accuracy of all reference points can meet the calibration requirements. When the aircraft assembly dimensions are greater than 25m and less than 50m, the measurement accuracy of all reference points can reach 0.165mm, and the measurement accuracy of most reference points can meet the calibration requirements. When the aircraft assembly dimensions are greater than 50m and less than 100m, the measurement accuracy can reach 0.315mm, but the measurement accuracy of most reference points is out of tolerance and cannot meet the calibration requirements.

[0004] Coordinate measuring machines (CMMs), which have higher precision than laser trackers, are often used for quality inspection of aircraft parts. However, in the aircraft assembly site, the size of aircraft parts is much larger than that of aircraft components, and the measurement site is much more complex, with many obstacles and other factors, making it impossible for CMMs to be used for the calibration of reference points in the aircraft assembly site.

[0005] Besides single-instrument point coordinate measurement, point coordinates can also be obtained through multi-instrument intersection measurement. Intersection measurement includes angular intersection measurement and length intersection measurement. Angular intersection measurement includes industrial photogrammetry, while length intersection measurement includes laser interferometer ranging. Industrial photogrammetry is based on the principle of natural light transmission. However, due to limitations in lens manufacturing precision and noise interference from natural light, the accuracy of angular intersection measurement is difficult to match that of laser trackers. In contrast, length intersection measurement based on laser interferometer ranging can achieve very high accuracy. Literature shows that interferometric ranging accuracy can reach 0.0003 mm / m. Even with a certain amount of intersection calculation error, the point accuracy based on multi-interferometric ranging intersection measurement can reach 0.1 mm / 100m.

[0006] However, large obstacles such as large tooling and large work platforms exist at the aircraft assembly site. If one-stop interferometric ranging is to obtain the coordinates of the reference point, complex mechanical rendezvous devices, extension devices and transfer devices are required. Although high measurement accuracy can be obtained, it also requires high cost and time, which is difficult to meet the rapid development requirements of modern aircraft such as "start riveting as soon as the drawing is issued" and "low-cost manufacturing".

[0007] Therefore, it is necessary to design a calibration method for the coordinates of a group of points at a large-scale aircraft assembly site that has a short preparation cycle, is economical and feasible, and meets the required accuracy. Summary of the Invention

[0008] The purpose of this application is to provide a large-scale reference point group coordinate calibration method based on interferometric intersection ranging to solve the prominent problems in accuracy, cost and time in the calibration of point coordinates at aircraft assembly sites on a scale of hundreds of meters.

[0009] The technical solution of this application is:

[0010] A method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, comprising:

[0011] Step 1: Divide the reference point group M into a connection set C and a region set R, wherein the reference points in the connection set C can be set on the foundation. Simultaneous observation by a laser interferometer;

[0012] Step 2: Divide the connection set C into a connection subsets and one independent subset. And divide the region set R into a region subsets, where the first region is the first subset of the region set R. A subset of contacts , No. a subset of regions The central reference point, which can be set up by the transfer station. group Simultaneous observation by a laser interferometer rangefinder ;

[0013] Step 3, place the first A subset of contacts , No. a subset of regions Perform a union fusion to obtain the first set. Individual districts combined ;

[0014] Step 4: Construct a connection set coordinate system based on connection set C. and constructing a connection set coordinate system The pose constraint equations;

[0015] Step 5, with A laser interferometric rangefinder was used to perform intersection ranging on the reference points in the connection set C, and a system of simultaneous equations was constructed to calculate the coordinates of the reference points in the connection set C in the connection set coordinate system. The coordinates below;

[0016] Step Six, based on the first Individual districts combined Construct the i-th joint set coordinate system And construct the i-th joint set coordinate system. The pose constraint equations;

[0017] Step 7: Setting up the transfer station group The first laser interferometer rangefinder, for the first Individual districts combined Intersection distance measurement is performed at the central benchmark point, and a system of simultaneous equations is constructed to solve the first equation. Individual districts combined The reference point is in the i-th joint coordinate system. The coordinates below;

[0018] Step 8: Place the first Individual districts combined The reference point is in the i-th joint coordinate system. Transform the coordinates below to the connection set coordinate system. Down;

[0019] Step 9, place the first A subset of contacts Independent subsets The reference point in the connection set coordinate system Transform the coordinates below to the point group coordinate system. Down.

[0020] Optionally, in the above method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step one includes:

[0021] ;

[0022] ;

[0023] ;

[0024] ;

[0025] in,

[0026] The number of reference points in reference point group M;

[0027] The number of reference points in the connection set C;

[0028] The number of reference points in the region set R;

[0029] when hour, ;when hour, ;when hour, .

[0030] Optionally, in the above method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step two includes:

[0031] ;

[0032] ;

[0033] ;

[0034] ;

[0035] ;

[0036] ;

[0037] ;

[0038] ;

[0039] in,

[0040] For the first A subset of contacts The number of reference points;

[0041] For independent subsets The number of reference points;

[0042] ;

[0043] ;

[0044] ;

[0045] ;

[0046] in,

[0047] For the first a subset of regions The number of reference points.

[0048] Optionally, in the above method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step three includes:

[0049] ;

[0050] ;

[0051] ;

[0052] in,

[0053] For the first Individual districts combined The number of reference points.

[0054] Optionally, in the above-described method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step four includes:

[0055] S41. Select three reference points, point 1, point 2, and point 3, from the connection set C. Points 1, 2, and 3 are not collinear, and the triangle formed by points 1, 2, and 3 has the largest area.

[0056] In the triangle formed by points 1, 2, and 3, the line connecting points 2 and 3 is the longer side, the line connecting points 1 and 2 is the middle side, and the line connecting points 1 and 3 is the shorter side.

[0057] Using point 1 as the coordinate system of the connection set The origin is defined by the line connecting points 1 and 2, forming the connection set coordinate system. The X-axis is defined by the plane containing points 1, 2, and 3 as the connection set coordinate system. The XOY plane, and the connection set coordinate system The angle between the Y-axis and the line connecting points 1 and 3 is less than or equal to 90°. The coordinate system of the connection set is determined according to the right-hand rule. The Z-axis;

[0058] S42, Constrained Connection Set Coordinate System The origin of point 1 is used to map point 1 in the connection set coordinate system. lower coordinate Three variables , , The constraint is 0, denoted as:

[0059] ;

[0060] Constrained connection set coordinate system The X-axis is used to map point 2 in the connection set coordinate system. lower coordinate Two variables , The constraint is 0, denoted as:

[0061] ;

[0062] Constrained connection set coordinate system On the XOY plane, point 3 is placed in the connection set coordinate system. lower coordinate A variable The constraint is 0, denoted as:

[0063] .

[0064] Optionally, in the above-described method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step five includes:

[0065] S51, with A laser interferometric rangefinder was used to measure the distance from the reference point in the communication set C to each laser interferometric rangefinder.

[0066] S52. Solve for the reference points in the connection set C in the connection set coordinate system. The following coordinates:

[0067] ;

[0068] ;

[0069] ;

[0070] in,

[0071] For the first Taiwanese laser interferometer in the communication set coordinate system The coordinates below;

[0072] For the connection set C, the first A reference point in the connection set coordinate system The coordinates below are represented by a vector. : = ;

[0073] For the first The laser interferometer measured the distance from the first point in the communication set C. The distance between the reference points;

[0074] for , Formula for calculating the distance between spaces.

[0075] Optionally, in the above-described method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step six includes:

[0076] S61, from the first Individual districts combined Three reference points, e, f, and g, are selected. Points e, f, and g are not collinear, and the triangle formed by points e, f, and g has the largest area.

[0077] In the triangle formed by points e, f, and g, the line connecting points f and g is the longer side, the line connecting points e and f is the middle side, and the line connecting points e and g is the shorter side.

[0078] Let point e be the coordinate system of the i-th joint region union. The origin is defined by the line connecting points e and f, which forms the i-th union coordinate system. The X-axis is defined by the plane containing points e, f, and g as the i-th joint coordinate system. The XOY plane, and the i-th joint region union coordinate system. The angle between the Y-axis and the line connecting points e and g is less than or equal to 90°. The right-hand rule is used to determine the coordinate system of the i-th joint region union. The Z-axis;

[0079] S62. Constrain the coordinate system of the union of the i-th connected regions. The origin of point e is used to define the coordinate system of the i-th joint region. lower coordinate Three variables , , The constraint is 0, denoted as:

[0080] ;

[0081] Constrain the coordinate system of the i-th joint region The X-axis is used to define the coordinate system of point f in the i-th joint region. lower coordinate Two variables , The constraint is 0, denoted as:

[0082] ;

[0083] Constrain the coordinate system of the i-th joint region The XOY plane, the coordinate system of point g in the i-th joint region. lower coordinate A variable The constraint is 0, denoted as:

[0084] .

[0085] Optionally, in the above-described method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step seven includes:

[0086] S71, the first station is built using the transfer station group The laser interferometer measured the first... Individual districts combined The distance from the central reference point to each laser interferometer;

[0087] S72, Solving the... Individual districts combined The reference point is in the i-th joint coordinate system. The following coordinates:

[0088] ;

[0089] ;

[0090] ;

[0091] in,

[0092] The first one erected for the transfer station Group 1 The laser interferometer is located in the i-th joint coordinate system. The coordinates below;

[0093] For the first Individual districts combined The Middle The reference point is in the i-th joint coordinate system. The coordinates below are represented by a vector. : = ;

[0094] The first one erected for the transfer station Group 1 The laser interferometer and the i-th joint coordinate system The Middle The distance between the reference points;

[0095] for , Formula for calculating the distance between spaces.

[0096] Optionally, in the above-described method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step eight includes:

[0097] S81, retrieve the first A subset of contacts Four reference points in the i-th joint coordinate system The coordinates below, and in the connection set coordinate system The coordinates below;

[0098] Let the coordinate system of the i-th joint region be... The lower coordinate vector is represented as , , and And the coordinates of points u, v, w, and t in the connection set coordinate system The vector representation of the lower coordinate is as follows , , and ;

[0099] S82. Construct the coordinate system of the i-th connected region union. With the connection set coordinate system Transformation matrix :

[0100] ;

[0101] S83, Solving the... Individual districts combined The reference point in the connection set coordinate system The following coordinates:

[0102] ;

[0103] For the first Individual districts combined The Middle A reference point connection set coordinate system The coordinates below.

[0104] Optionally, in the above method for calibrating the coordinates of a large group of reference points based on interferometric rendezvous ranging, step nine specifically includes:

[0105] ;

[0106] in,

[0107] For the first A subset of contacts Independent subsets The reference point o is in the connection set coordinate system. The coordinates below;

[0108] Point group coordinate system With the connection set coordinate system The transformation relationship;

[0109] For the first A subset of contacts Independent subsets The central reference point o, in the point group coordinate system The coordinates below.

[0110] This application has at least the following beneficial technical effects:

[0111] This paper presents a method for calibrating the coordinates of a large-scale reference point group based on interferometric intersection ranging. Building upon the measurement of reference point coordinates using interferometric intersection ranging, this method employs a point group classification, grouping by category, and inter-group fusion approach to calibrate the coordinates of the reference point group. This method solves the problem of obtaining point coordinates directly through interferometric intersection ranging in large-scale aircraft assembly sites where optical path obstacles exist. It achieves high-precision, low-cost, and high-efficiency calibration of the reference point group coordinates, supporting the construction of a digital assembly coordinate system for aircraft. Attached Figure Description

[0112] Figure 1 This is a schematic diagram of an aircraft assembly site provided in an embodiment of this application;

[0113] Figure 2 This is a schematic diagram illustrating the division of a reference point group M into a connection set C and a region set R, as provided in an embodiment of this application.

[0114] Figure 3 The embodiment of this application provides a method for dividing a contact set C into a contact subsets and one independent subset. And a schematic diagram of dividing the region set R into a region subsets;

[0115] Figure 4 This is a schematic diagram of performing a union of a connection subset and its corresponding region subset to obtain a connection region union, as provided in an embodiment of this application.

[0116] Figure 5 The embodiments provided in this application are based on the first Individual districts combined Construct the i-th joint set coordinate system A schematic diagram;

[0117] in:

[0118] 1-Foundation; 2-Laser interferometer; 3-Assembly fixture.

[0119] To better illustrate this embodiment, some content in the accompanying drawings may be omitted, enlarged, or reduced. They are for illustrative purposes only and should not be construed as limiting the scope of this application. Detailed Implementation

[0120] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, and other related parts can be referred to the general design.

[0121] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The word "comprising" as used in this application description indicates that the concept preceding the word encompasses the concepts listed following the word and their equivalents, without excluding other related concepts.

[0122] The coordinate calibration of reference points at the assembly site of large and complex aircraft faces significant challenges, including difficulty in direct measurement, high measurement costs, and long measurement cycles. These challenges are detailed below:

[0123] The aircraft assembly site is large in scale, with dimensions reaching hundreds of meters. In addition, a large number of process equipment, work platforms and other large structures are placed in the aircraft assembly site, making it difficult for the optical paths of the reference points in the aircraft assembly site to be directly connected in pairs, and making it impossible to obtain the interferometric ranging of all points in one measurement.

[0124] Laser interferometers are generally used to measure high-precision distances, but they are greatly limited in intersection measurements. They require complex mechanical intersection devices, which are difficult to modularize and make universal, resulting in high measurement costs and long cycles.

[0125] To address the challenges of accuracy, cost, and time-consuming calibration of reference points at the 100-meter-level aircraft assembly site, this application provides a method for calibrating large-size reference point group coordinates based on interferometric intersection ranging.

[0126] Step 1: Divide the reference point group M into a connection set C and a region set R, wherein the reference points in the connection set C can be set on the foundation 1. Two laser interferometers simultaneously observed this.

[0127] Assembly fixtures 3 are arranged on the foundation 1, which interrupts the optical path between some reference points.

[0128] ;

[0129] ;

[0130] ;

[0131] ;

[0132] in,

[0133] The number of reference points in reference point group M;

[0134] The number of reference points in the connection set C;

[0135] The number of reference points in the region set R.

[0136] In a specific example, the aircraft assembly site is 100 meters long and 15 meters wide. Foundation 1 is a 1.2-meter-thick, high-rigidity foundation. 38 reference points for constructing the assembly coordinate system are laid out on foundation 1, along with two assembly fixtures 3. This causes the optical paths between some reference points to be interrupted. To accurately calibrate the coordinates of the reference points, four laser interferometers 2 are installed on foundation 1. Figure 1 As shown, there are , The reference point group M is divided into a connection set C and a region set R. , The 12 reference points in the connection set C can be observed simultaneously by 4 laser interferometers 2, such as Figure 2 As shown.

[0137] The laser interferometric rangefinder 2 can use the interferometric ranging module of a laser tracker.

[0138] when hour, ;when hour, ;when hour, .

[0139] Step 2: Divide the connection set C into a connection subsets and one independent subset. And divide the region set R into a region subsets, where the first region is the first subset of the region set R. A subset of contacts , No. a subset of regions The central reference point, which can be set up by the transfer station. group Two laser interferometers simultaneously observed that , .

[0140] ;

[0141] ;

[0142] ;

[0143] ;

[0144] ;

[0145] ;

[0146] ;

[0147] in,

[0148] For the first A subset of contacts The number of reference points;

[0149] For independent subsets The number of reference points.

[0150] ;

[0151] ;

[0152] ;

[0153] ;

[0154] in,

[0155] For the first a subset of regions The number of reference points.

[0156] In a specific example, , , , , , , , ,like Figure 3 As shown.

[0157] Step 3, place the first A subset of contacts , No. a subset of regions Perform a union fusion to obtain the first set. Individual districts combined The reference point can be set up by the transfer station. group Two laser interferometers simultaneously observed this.

[0158] ;

[0159] ;

[0160] ;

[0161] in,

[0162] For the first Individual districts combined The number of reference points.

[0163] In a specific example, , Among them, joint districts and collection In Each reference point can be used by the first group. Simultaneous observation by the laser interferometer at the transfer station showed that the combined area was... In The reference points can be used by the second group. Simultaneous observations by the laser interferometric rangefinder at the transfer station, such as Figure 4 As shown.

[0164] Step 4: Construct a connection set coordinate system based on connection set C. and constructing a connection set coordinate system The pose constraint equations.

[0165] S41. Select three reference points, point 1, point 2, and point 3, from the connection set C. Points 1, 2, and 3 are not collinear, and the triangle formed by points 1, 2, and 3 has the largest area.

[0166] In the triangle formed by points 1, 2, and 3, the line connecting points 2 and 3 is the longer side, the line connecting points 1 and 2 is the middle side, and the line connecting points 1 and 3 is the shorter side.

[0167] Using point 1 as the coordinate system of the connection set The origin is defined by the line connecting points 1 and 2, forming the connection set coordinate system. The X-axis is defined by the plane containing points 1, 2, and 3 as the connection set coordinate system. The XOY plane, and the connection set coordinate system The angle between the Y-axis and the line connecting points 1 and 3 is less than or equal to 90°. The coordinate system of the connection set is determined according to the right-hand rule. The Z-axis. Connection set coordinate system. The X, Y, and Z axes are all orthogonal to each other, such as Figure 2 As shown.

[0168] S42, Constrained Connection Set Coordinate System The origin of point 1 is used to map point 1 in the connection set coordinate system. lower coordinate Three variables , , The constraint is 0, denoted as:

[0169] ;

[0170] Constrained connection set coordinate system The X-axis is used to map point 2 in the connection set coordinate system. lower coordinate Two variables , The constraint is 0, denoted as:

[0171] ;

[0172] Constrained connection set coordinate system On the XOY plane, point 3 is placed in the connection set coordinate system. lower coordinate A variable The constraint is 0, denoted as:

[0173] .

[0174] Step 5, with The laser interferometric rangefinder 2 is used to perform intersection ranging on the reference points in the communication set C, such as... Figure 2 As shown, a system of simultaneous equations is constructed to solve for the reference points in the connection set C in the connection set coordinate system. The coordinates below.

[0175] S51, with A laser interferometer 2 is used to measure the distance from the reference point in the communication set C to each laser interferometer 2.

[0176] S52. Solve for the reference points in the connection set C in the connection set coordinate system. The following coordinates:

[0177] ;

[0178] ;

[0179] ;

[0180] in,

[0181] For the first Taiwan laser interferometer 2 in the communication set coordinate system The coordinates below;

[0182] For the connection set C, the first A reference point in the connection set coordinate system The coordinates below are represented by a vector. : = ;

[0183] For the first The laser interferometer 2 measured the distance from the contact set C. The distance between the reference points;

[0184] for , Formula for calculating the distance between spaces.

[0185] In the specific example, the number of intersection distance measurements for each reference point in the connection set C is: =4 times, the number of reference points measured by each laser interferometer is 2. =12, a total of 12 were measured. The system of equations contains [number] distance values. equations and =42 unknowns, the number of equations is greater than the number of unknowns, and the coordinates of each reference point in the connection set C in the connection set coordinate system can be solved. The coordinates below, where points 1, 2, 3, and 4 are in the connection set coordinate system. The coordinate vectors below are respectively , , , .

[0186] Step Six, based on the first Individual districts combined Construct the i-th joint set coordinate system And construct the i-th joint set coordinate system. The pose constraint equations.

[0187] S61, from the first Individual districts combined Three reference points, e, f, and g, are selected. Points e, f, and g are not collinear, and the triangle formed by points e, f, and g has the largest area.

[0188] In the triangle formed by points e, f, and g, the line connecting points f and g is the longer side, the line connecting points e and f is the middle side, and the line connecting points e and g is the shorter side.

[0189] Let point e be the coordinate system of the i-th joint region union. The origin is defined by the line connecting points e and f, which forms the i-th union coordinate system. The X-axis is defined by the plane containing points e, f, and g as the i-th joint coordinate system. The XOY plane, and the i-th joint region union coordinate system. The angle between the Y-axis and the line connecting points e and g is less than or equal to 90°. The right-hand rule is used to determine the coordinate system of the i-th joint region union. The Z-axis. The coordinate system of the i-th joint region. The X-axis, Y-axis and Z-axis are all orthogonal to each other.

[0190] S62. Constrain the coordinate system of the union of the i-th connected regions. The origin of point e is used to define the coordinate system of the i-th joint region. lower coordinate Three variables , , The constraint is 0, denoted as:

[0191] ;

[0192] Constrain the coordinate system of the i-th joint region The X-axis is used to define the coordinate system of point f in the i-th joint region. lower coordinate Two variables , The constraint is 0, denoted as:

[0193] ;

[0194] Constrain the coordinate system of the i-th joint region The XOY plane, the coordinate system of point g in the i-th joint region. lower coordinate A variable The constraint is 0, denoted as:

[0195] .

[0196] In a specific example, based on the first union of regions The second joint area is combined. Constructing the first joint set coordinate system The second joint region coordinate system Among them, the second joint region union coordinate system The construction, such as Figure 5 As shown.

[0197] Step 7: Setting up the transfer station group The second laser interferometer rangefinder, for the first Individual districts combined Intersection distance measurement is performed at the central benchmark point, and a system of simultaneous equations is constructed to solve the first equation. Individual districts combined The reference point is in the i-th joint coordinate system. The coordinates below.

[0198] S71, the first station is built using the transfer station group The second laser interferometer measured the... Individual districts combined The distance from the central reference point to each laser interferometer 2.

[0199] The first group The laser interferometer rangefinder was set up at the No. 2 transfer station. Individual districts combined At the rigid location around the central reference point.

[0200] S72, Solving the... Individual districts combined The reference point is in the i-th joint coordinate system. The following coordinates:

[0201] ;

[0202] ;

[0203] ;

[0204] in,

[0205] The first one erected for the transfer station Group 1 The laser interferometer 2 is in the i-th joint coordinate system. The coordinates below;

[0206] For the first Individual districts combined The Middle The reference point is in the i-th joint coordinate system. The coordinates below are represented by a vector. : = ;

[0207] The first one erected for the transfer station Group 1 The laser interferometer 2 and the i-th joint coordinate system The Middle The distance between the reference points;

[0208] for , Formula for calculating the distance between spaces.

[0209] In a specific example, the second group was set up at the transfer station. Two laser interferometers were used to measure the second union of the connected regions. The distance from the central reference point to each laser interferometric rangefinder 2, such as Figure 5 As shown, the second joint region union The number of intersection distance measurements at each reference point is =4 times, the number of measurement reference points for the second group of laser interferometric rangefinders set up at each transfer station is 2. A total of [number] samples were measured. The system of equations contains [number] distance values. equations and With one unknown quantity and a number of equations greater than the number of unknown quantities, the second joint union of regions can be solved. In the i-th joint coordinate system, each reference point is a coordinate system of the first joint region. The coordinates below, where points e, f, g, and h are in the second union coordinate system. The coordinate vectors below are respectively , , and .

[0210] Step 8: Place the first Individual districts combined The reference point is in the i-th joint coordinate system. Transform the coordinates below to the connection set coordinate system. Down.

[0211] S81, retrieve the first A subset of contacts The four reference points, midpoint u, point v, point w, and point t, are in the i-th joint coordinate system. The coordinates below, and in the connection set coordinate system The coordinates below;

[0212] Let the coordinate system of the i-th joint region be... The lower coordinate vector is represented as , , and And the coordinates of points u, v, w, and t in the connection set coordinate system The vector representation of the lower coordinate is as follows , , and .

[0213] S82. Construct the coordinate system of the i-th connected region union. With the connection set coordinate system Transformation matrix :

[0214] ;

[0215] S83, Solving the... Individual districts combined The reference point in the connection set coordinate system The following coordinates:

[0216] ;

[0217] For the first Individual districts combined The Middle A reference point connection set coordinate system The coordinates below.

[0218] In a specific example, the first contiguous region is joined together. 20 reference points in the middle, the second joint area set Transform the coordinates of the 18 reference points to the connection set coordinate system Down.

[0219] Step 9, place the first A subset of contacts Independent subsets The reference point in the connection set coordinate system Transform the coordinates below to the point group coordinate system. The following refers to placing the reference points in the connection set C and the region set R in the connection set coordinate system. The coordinates below are uniformly calibrated to the point group coordinate system. Below, the coordinate system of all reference points in the point group is realized. Measurement calibration below.

[0220] ;

[0221] in,

[0222] For the first A subset of contacts Independent subsets Let reference point o represent any reference point in the reference point group M, in the connection set coordinate system. The coordinates below;

[0223] Point group coordinate system With the connection set coordinate system The transformation relationship;

[0224] For the first A subset of contacts Independent subsets The central reference point o, in the point group coordinate system The coordinates below.

[0225] In a specific example, the first contiguous region will be joined together. 20 reference points in the middle, the second joint area set The 18 reference points in the connection set coordinate system Transform the coordinates below to the point group coordinate system. Below, and the point group coordinate system With the connection set coordinate system They overlap, therefore ,have:

[0226] .

[0227] The above embodiments disclose a method for calibrating large-size reference point group coordinates based on interferometric rendezvous ranging.

[0228] To address the issue that laser interferometric rangefinders cannot directly calculate the coordinates of reference points through intersection ranging, this paper proposes a method that divides the reference point group into different sets and performs interferometric intersection ranging transfer and fusion between these sets. This enables interferometric intersection ranging in aircraft assembly sites where the optical path is obstructed and the process is complex, while ensuring high accuracy in measuring the coordinates of the reference points.

[0229] Dividing a large set of reference points into two sets, the connection point set and the regional point set, can minimize the number of different measurement stations and reduce the number of station transfers in interferometric cross-section measurements, thus achieving a good balance between accuracy and efficiency in measuring the coordinates of reference points.

[0230] Replacing the laser interferometer with the interferometric ranging module of the laser tracker allows the laser to be reflected by a general prism reflector target ball, eliminating the need for a special interferometric mirror and a complex mechanical intersection interferometric ranging device. This reduces the cycle and cost of interferometric ranging of reference points in complex environments.

[0231] The large-size reference point group coordinate calibration method based on relay interferometric ranging disclosed in the above embodiments has been technically transferred to the measurement of reference point group coordinates on aircraft assembly lines of 80-100 meters, significantly improving the accuracy of reference point calibration at the assembly site and shortening the cost and cycle of measurement and calibration. Furthermore, the large-size reference point group coordinate calibration method based on relay interferometric ranging disclosed in the above embodiments has significant comprehensive advantages in terms of calibration accuracy, calibration cycle, and calibration cost for calibration projects with point group coordinates requiring 0.1mm / 100m accuracy. It can be applied to the calibration of large-size, high-precision point coordinates in aviation and aerospace, such as for the calibration of point coordinates on large-size, high-precision reusable rocket assembly lines.

[0232] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for calibrating the coordinates of a large group of reference points based on interferometric intersection ranging, characterized in that, include: Step 1: Divide the reference point group M into a connection set C and a region set R, wherein the reference points in the connection set C can be set on the foundation (1). Simultaneous observation by a laser interferometer (2); Step 2: Divide the connection set C into a connection subsets and one independent subset. And divide the region set R into a region subsets, where the first region is the first subset of the region set R. A subset of contacts , No. a subset of regions The central reference point, which can be set up by the transfer station. group The laser interferometer (2) simultaneously observed that ; Step 3, place the first A subset of contacts , No. a subset of regions Perform a union fusion to obtain the first set. Individual districts combined ; Step 4: Construct a connection set coordinate system based on connection set C. and constructing a connection set coordinate system The pose constraint equations; Step 5, with A laser interferometric rangefinder (2) is used to perform intersection distance measurement on the reference points in the connection set C, and a system of simultaneous equations is constructed to solve for the reference points in the connection set C in the connection set coordinate system. The coordinates below; Step Six, based on the first Individual districts combined Construct the i-th joint set coordinate system And construct the i-th joint set coordinate system. The pose constraint equations; Step 7: Setting up the transfer station group The laser interferometer (2) is used for the first... Individual districts combined Intersection distance measurement is performed at the central benchmark point, and a system of simultaneous equations is constructed to solve the first equation. Individual districts combined The reference point is in the i-th joint coordinate system. The coordinates below; Step 8: Place the first Individual districts combined The reference point is in the i-th joint coordinate system. Transform the coordinates below to the connection set coordinate system. Down; Step 9, place the first A subset of contacts Independent subsets The reference point in the connection set coordinate system Transform the coordinates below to the point group coordinate system. Down.

2. The method for calibrating the coordinates of a large-size reference point group based on interferometric intersection ranging according to claim 1, characterized in that, In step one: ； ； ； ； in, The number of reference points in reference point group M; The number of reference points in the connection set C; The number of reference points in the region set R; when hour, ;when hour, ;when hour, .

3. The method for calibrating the coordinates of a large-size reference point group based on interferometric intersection ranging according to claim 2, characterized in that, Step two includes: ； ； ； ； ； ； ； ； in, For the first A subset of contacts The number of reference points; For independent subsets The number of reference points; ； ； ； ； in, For the first a subset of regions The number of reference points.

4. The method for calibrating large-size reference point group coordinates based on interferometric intersection ranging according to claim 3, characterized in that, Step three includes: ； ； ； in, For the first Individual districts combined The number of reference points.

5. The method for calibrating large-size reference point group coordinates based on interferometric intersection ranging according to claim 4, characterized in that, Step four includes: S41. Select three reference points, point 1, point 2, and point 3, from the connection set C. Points 1, 2, and 3 are not collinear, and the triangle formed by points 1, 2, and 3 has the largest area. In the triangle formed by points 1, 2, and 3, the line connecting points 2 and 3 is the longer side, the line connecting points 1 and 2 is the middle side, and the line connecting points 1 and 3 is the shorter side. Using point 1 as the coordinate system of the connection set The origin is defined by the line connecting points 1 and 2, forming the connection set coordinate system. The X-axis is defined by the plane containing points 1, 2, and 3 as the connection set coordinate system. The XOY plane, and the connection set coordinate system The angle between the Y-axis and the line connecting points 1 and 3 is less than or equal to 90°. The coordinate system of the connection set is determined according to the right-hand rule. The Z-axis; S42, Constrained Connection Set Coordinate System The origin of point 1 is used to map point 1 in the connection set coordinate system. lower coordinate Three variables , , The constraint is 0, denoted as: ； Constrained connection set coordinate system The X-axis is used to map point 2 in the connection set coordinate system. lower coordinate Two variables , The constraint is 0, denoted as: ； Constrained connection set coordinate system On the XOY plane, point 3 is placed in the connection set coordinate system. lower coordinate A variable The constraint is 0, denoted as: 。 6. The method for calibrating the coordinates of a large-size reference point group based on interferometric intersection ranging according to claim 5, is characterized in that, Step five includes: S51, with The distance from the reference point in the communication set C to each laser interferometer (2) was measured using a laser interferometer (2). S52. Solve for the reference points in the connection set C in the connection set coordinate system. The following coordinates: ； ； ； in, For the first The laser interferometer (2) in the connection set coordinate system The coordinates below; For the connection set C, the first A reference point in the connection set coordinate system The coordinates below are represented by a vector. : = ; For the first The laser interferometer (2) measured the distance from the first laser in the contact set C. The distance between the reference points; for , Formula for calculating the distance between spaces.

7. The method for calibrating large-size reference point group coordinates based on interferometric intersection ranging according to claim 6, characterized in that, Step six includes: S61, from the first Individual districts combined Three reference points, e, f, and g, are selected. Points e, f, and g are not collinear, and the triangle formed by points e, f, and g has the largest area. In the triangle formed by points e, f, and g, the line connecting points f and g is the longer side, the line connecting points e and f is the middle side, and the line connecting points e and g is the shorter side. Let point e be the coordinate system of the i-th joint region union. The origin is defined by the line connecting points e and f, which forms the i-th union coordinate system. The X-axis is defined by the plane containing points e, f, and g as the i-th joint coordinate system. The XOY plane, and the i-th joint region union coordinate system. The angle between the Y-axis and the line connecting points e and g is less than or equal to 90°. The right-hand rule is used to determine the coordinate system of the i-th joint region union. The Z-axis; S62. Constrain the coordinate system of the union of the i-th joint regions. The origin of point e is used to define the coordinate system of the i-th joint region. lower coordinate Three variables , , The constraint is 0, denoted as: ； Constrain the coordinate system of the i-th joint region The X-axis is used to define the coordinate system of point f in the i-th joint region. lower coordinate Two variables , The constraint is 0, denoted as: ； Constrain the coordinate system of the i-th joint region The XOY plane, the coordinate system of point g in the i-th joint region. lower coordinate A variable The constraint is 0, denoted as: 。 8. The method for calibrating large-size reference point group coordinates based on interferometric intersection ranging according to claim 7, characterized in that, Step seven includes: S71, the first station is built using the transfer station group The laser interferometer (2) measured the first... Individual districts combined The distance from the central reference point to each laser interferometer (2); S72, Solving the... Individual districts combined The reference point is in the i-th joint coordinate system. The following coordinates: ； ； ； in, The first one erected for the transfer station Group 1 The laser interferometer (2) in the i-th joint coordinate system The coordinates below; For the first Individual districts combined The Middle The reference point is in the i-th joint coordinate system. The coordinates below are represented by a vector. : = ; The first one erected for the transfer station Group 1 The laser interferometer (2) and the i-th joint coordinate system The Middle The distance between the reference points; for , Formula for calculating the distance between spaces.

9. The method for calibrating the coordinates of a large-size reference point group based on interferometric intersection ranging according to claim 8, characterized in that, Step eight includes: S81, retrieve the first A subset of contacts The four reference points, midpoint u, point v, point w, and point t, are in the i-th joint coordinate system. The coordinates below, and in the connection set coordinate system The coordinates below; Let the coordinate system of the i-th joint region be... The lower coordinate vector is represented as , , and And the coordinates of points u, v, w, and t in the connection set coordinate system The vector representation of the lower coordinate is as follows , , and ; S82. Construct the coordinate system of the i-th connected region union. With connection set coordinate system Transformation matrix : ； S83, Solving the... Individual districts combined The reference point in the connection set coordinate system The following coordinates: ； For the first Individual districts combined The Middle A reference point connection set coordinate system The coordinates below.

10. The method for calibrating the coordinates of a large-size reference point group based on interferometric intersection ranging according to claim 9, characterized in that, Step nine is as follows: ； in, For the first A subset of contacts Independent subsets The reference point o is in the connection set coordinate system. The coordinates below; Point group coordinate system With connection set coordinate system The transformation relationship; For the first A subset of contacts Independent subsets The central reference point o, in the point group coordinate system The coordinates below.

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