Target-accuracy-based continuity design method for large-scale measurement field

Abstract

The present application relates to the technical field of aircraft assembly, and in particular to a target-accuracy-based continuity design method for a large‑scale measurement field. The method comprises: on the basis of distance-measurement accuracy parameters of a measurement device, calculating a first measurement distance under tooling accuracy requirements; determining a minimum number of measurement devices on the basis of the first measurement distance, and correcting the minimum number of measurement devices to obtain a first number of measurement devices; obtaining final measurement distances of all the measurement devices along a longest measurement line by means of mutual correction between the number of measurement devices and the measurement distance; calculating continuity spacings of coordinate‑system datum points on the longest measurement line on the basis of the measurement distances; and completing the layout of the coordinate‑system datum points on the longest measurement line. The present application can satisfy the measurement accuracy requirements of tooling and ensure the manufacturing accuracy of aircraft products.

Description

Target accuracy-based large-size measurement field continuity design method TECHNICAL FIELD

[0001] The application belongs to the technical field of aircraft assembly, and particularly relates to a target accuracy-based large-size measurement field continuity design method. BACKGROUND

[0002] An aircraft tooling is a tool or structure used to assist aircraft manufacturing and assembly, and the accuracy of positioning components and positioning holes on the tooling is generally selected according to 1 / 3-1 / 5 of the aircraft product manufacturing accuracy according to the aviation manufacturing engineering manual, the national military standard and the aviation industry standard. When each tooling is manufactured, a measurement field including multiple measurement reference points and multiple measurement stations needs to be established.

[0003] The measurement reference points generally include a system-building reference point TB point and an extended reference system ERS point. In the past decade, most measurement reference points of tooling systems only set the ERS point, and the optical adjustment method and the least square method of multiple point coordinates are used to fit the coordinate system. In the tooling development process, the role of ERS actually mainly includes three parts of system building, station conversion and detection. According to the current division, the measurement reference points that have an impact on the length of the point spacing in each coordinate direction of the reference coordinate system are arranged at a spacing that directly affects the accuracy of establishing the reference coordinate system. Most of these points are regularly arranged on the tooling structure, and these points are called system-building reference points. The other measurement reference points for establishing the reference coordinate system that are outside the system-building reference points and cannot meet the measurement spacing requirements but are within the measurement envelope are part of the reference points for increasing the envelope of the reference coordinate system and meeting the system-building point number requirements of the reference coordinate system. These reference points are called system-building extended points. The minimum number of common reference points belonging to two measurement stations is required for the coordinate conversion process of a local measurement station in the reference coordinate system to another local measurement station. These common reference points are arranged in the overlapping area between the two stations. The size of the overlapping area of the common reference points of the measurement reference points of the two stations before and after the station conversion will affect the relative accuracy of the station after the station conversion and the station before the station conversion in the global coordinate system. According to the degree of accuracy influence of the common area, the overlapping area accounts for more than 1 / 4 of the area measurement station. These common reference points are called station conversion common points. The system-building extended points and the station conversion common points are collectively referred to as extended reference points. In addition, the reference points for monitoring the stability of the tooling structure or the foundation are constructed on the tooling structure, especially the tooling foundation. These reference points mainly serve as signs for monitoring the deformation of the tooling structure or the foundation settlement. The measurement data can directly reflect the deformation of the tooling structure and the foundation and indirectly reflect the stability of the entire reference system. These points are called stable reference points. The system-building reference points, the extended reference points and the stable reference points can overlap in the measurement reference system, but their actual functions are slightly different.

[0004] The extension reference point, the stable reference point and the system reference point belong to the main work content of the continuity design of the large tooling measurement field. The reference point spacing containing the extension reference point, the stable reference point and the system reference point continuity design content is mostly arranged according to the requirements that "less than 300mm will not increase the system accuracy, more than 800mm will reduce the system accuracy, and the maximum size should not be greater than 1400mm", but for the large assembly system, the reference points are too many and too dense according to the 300-1400mm spacing rule, which seriously affects the tooling function, so in the actual development, the reference point spacing of the large assembly system is different from 2m to 5m, and in some scenes, the reference point spacing is even greater than 10m.

[0005] Through long-term measurement practice, for the tooling measurement field below 10m, the system reference point, the extension reference point and the stable reference point are arranged regardless of how to set, and the envelope formed by the measurement has little effect on the accuracy of the measured object. However, for the tooling measurement field above 10m, the different envelopes formed by the arrangement of the measurement reference points have an effect on the accuracy of the measured object, and even exceed the assembly accuracy requirement. The arrangement of the related system reference point, the extension reference point and the stable reference point has no standard rule so far, and for various tooling measurement fields, especially for the tooling measurement field above 10m, the accuracy influence on the measured object cannot be quantitatively evaluated, and cannot be directly reflected on the arrangement spacing of the measurement reference points, so that the influence on the final assembly accuracy of the aircraft product cannot be accurately predicted. SUMMARY

[0006] In order to solve the above technical problems, the application provides a large-size measurement field continuity design method based on target accuracy, mainly including:

[0007] Step S1, calculating a first distance under the tooling required accuracy according to the ranging accuracy parameter of the measurement equipment;

[0008] Step S2, determining the minimum number of measurement equipment according to the first distance, and correcting to obtain the first number of measurement equipment;

[0009] Step S3, correcting the first distance according to the ratio of the minimum number of measurement equipment and the first number of measurement equipment to obtain a second distance;

[0010] Step S4, uniformly distributing the measurement equipment in the measurement field according to the first number of measurement equipment, so that the measurement equipment maximally envelopes the measurement points of each tooling structure;

[0011] Step S5, correcting the first number of measurement equipment based on the distance between the measurement equipment and the longest measurement line to obtain a second number of measurement equipment;

[0012] Step S6, correcting the second distance measurement according to the ratio of the first number of measurement devices to the second number of measurement devices to obtain a third distance measurement;

[0013] Step S7, calculating a first continuity interval of the datum points on the longest measurement line according to the third distance measurement and the tooling required accuracy, and calculating a second continuity interval of the datum points on the longest measurement line according to the third distance measurement and the actual distance measurement accuracy corresponding thereto;

[0014] Step S8, performing operation on the first continuity interval and the second continuity interval according to the longest measurement line to obtain a third continuity interval, and completing the layout of the datum points on the longest measurement line according to the third continuity interval.

[0015] Preferably, step S2 further comprises:

[0016] Step S21, calculating the least number of measurement devices along the longest measurement line of the tooling measurement field according to the first distance measurement;

[0017] Step S22, correcting the least number of measurement devices based on a given repositioning error;

[0018] Step S23, rounding up the corrected least number of measurement devices to obtain the first number of measurement devices.

[0019] Preferably, in step S22, the correction coefficient ρ2=(σ1+σ) / σ, wherein σ1 is the repositioning error and σ is the tooling required accuracy.

[0020] Preferably, step S5 further comprises:

[0021] Step S51, determining the vertical distance between the measurement device and the longest measurement line according to the position of the actually arranged measurement device;

[0022] Step S52, calculating a deviation correction coefficient according to the vertical distance and the second distance measurement;

[0023] Step S53, correcting the first number of measurement devices according to the deviation correction coefficient, and rounding up to form the second number of measurement devices.

[0024] Preferably, step S7 further comprises:

[0025] The first continuity interval C1 is calculated according to the following formula:

[0026] C1=2.5*σ*L4;

[0027] The second continuity interval C2 is calculated according to the following formula:

[0028] C2=40*(σ-σ2)+0.8;

[0029] Wherein, σ is the tooling requirement precision, σ2 is the actual ranging precision corresponding to the third ranging L4.

[0030] Preferably, further comprising boundary limiting the second continuity spacing C2:

[0031] When C2<0.3m, C2 is modified to 0.3m; when the longest ranging line length L<5m and C2>0.8m, C2 is modified to 0.8m; when 5m≤L<10m and C2>1.4m, C2 is modified to 1.4m; when L≥10m and C2>5m, C2 is modified to 5m.

[0032] Preferably, step S8 further comprises:

[0033] When L≤10m, the third continuity spacing C3 is set as: C3≤min(C1, C2);

[0034] When 10<L≤20m, the third continuity spacing C3 is set as: C3≤(c1+c2) / 2;

[0035] When L>20m, the third continuity spacing C3 is set as: C3≤max(C1, C2).

[0036] Preferably, step S8 further comprises:

[0037] Step S9, determining the arrangement spacing C4 of the extended reference point according to the third continuity spacing C3 and the longest measuring line L: C4≤min(2*C3, L / 5);

[0038] Step S10, determining the arrangement spacing C5 of the stable reference point according to the longest measuring line L: C5≤min(5m, L / 3).

[0039] The present application can meet the tooling measurement precision requirement, and ensure the manufacturing precision of the aircraft product. BRIEF DESCRIPTION OF DRAWINGS

[0040] Fig. 1 is a schematic diagram of the arrangement of each measuring point of a preferred embodiment of the target precision-based large-size measurement field continuity design method of the present application.

[0041] Wherein, 1-tooling structure; 2-establishment reference point; 3-extended reference point; 4-stable reference point; 5-measuring point; 6-bottom plane; 7-measuring station. DETAILED DESCRIPTION

[0042] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described in a more detailed manner in the below with reference to the drawings in the embodiments of the present application. Identical or similar numerals in the drawings represent identical or similar elements or elements with identical or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0043] The present application provides a large-size measurement field continuity design method based on target accuracy, which mainly aims to design the spacing between the measurement reference points of the continuity arrangement of the large-size measurement field, so that each type of measurement reference point can meet the tooling measurement accuracy requirement, and finally ensure the manufacturing accuracy of the aircraft product.

[0044] Firstly, referring to FIG. 1, the tooling structure 1 and the measurement station 7 are arranged above the bottom plane 6; the system reference point 2, the extended reference point 3 and the stable reference point 4 are obtained by subdividing the traditional measurement field ERS reference point according to the function, and since they have similar arrangement characteristics, they are also part of the continuity design work. These reference points are arranged on the surface of the tooling structure 1 or the bottom plane 6. Among them, the system reference point 2 is a reference point for measuring field system stability compensation with the smallest influence on measurement accuracy within a certain spacing. According to the laser measurement field at home and abroad, the conventional arrangement spacing is 0.3m-1.4m, and there are cases of large-size measurement spacing of 0.8m-10m. The system reference point 2 in FIG. 1 includes 15 in the horizontal direction and 6 in each column in the vertical direction; the extended reference point 3 is mainly an extended reference point for increasing the envelope of the reference coordinate system, satisfying the number of reference points of the reference coordinate system, and a station conversion public point for improving the station conversion accuracy. In FIG. 1, the extended reference point 3 is determined according to the minimum reference point number requirement of each of the 4 measurement stations, the minimum number of station conversion public points and the related station conversion requirements of the minimum range. On the basis of the system reference point 2, each station adds 2-4 extended reference points 3; the stable reference point 4 is a measurement reference point for monitoring the stability of the tooling structure or the foundation. The spacing is determined according to the deflection deformation calculation of the tooling structure or the foundation and the system accuracy requirement of the measurement field. The stable reference point 4 is generally arranged on the surface of the foundation. According to the arrangement rule, the structure is uniformly arranged in 2 rows and 11 columns from top to bottom; the system reference point 2, the extended reference point 3 and the stable reference point 4 can be overlapped at local positions.

[0045] The purpose of the present application is to determine the spacing requirements between adjacent building reference points 2, between adjacent extension reference points 3, and between adjacent stable reference points 4, in order to arrange these reference points in the measurement field.

[0046] The target accuracy-based large-size measurement field continuity design method provided by the present application is shown in FIG. 1, and mainly includes:

[0047] Step S1: according to the ranging accuracy parameters of the measurement equipment, the first ranging under the tooling required accuracy is calculated.

[0048] In this step, the ranging accuracy parameters include ranging constant and ranging coefficient, and the ranging accuracy formula is generally expressed as: ranging accuracy = ranging constant + ranging coefficient * ranging. Taking a certain type of laser tracker as an example, the ranging constant is 15 μm, and the ranging coefficient is 6 μm. The tooling required accuracy σ = 0.1 mm is taken as the ranging accuracy and substituted into the ranging accuracy formula, i.e. 0.1 mm = 100 μm = 15 μm + 6 μm * L1, and the first ranging L1 of the measurement equipment in the station is calculated to be 14.16 m.

[0049] In this embodiment, the measurement range of each measurement equipment is represented by a circle. In FIG. 1, the four circles represent the respective measurement ranges of the four measurement equipments, and the center points of the circles are the measurement stations 7 of the corresponding measurement equipments. Ranging generally refers to the size of the longest ranging line that can be covered by the measurement equipment. The ranging calculated in step S1 is not the final ranging described in FIG. 1, but a maximum ranging, which will be continuously corrected in subsequent steps.

[0050] Step S2: determine the minimum number of measurement equipments according to the first ranging, and correct it to obtain the first number of measurement equipments.

[0051] It can be understood that with the ranging of each measurement equipment, the number of measurement equipments can be calculated according to the total measurement requirement size. In this embodiment, the total measurement requirement size can be represented by L, which is obtained by measuring the longest measurement line. The longest measurement line refers to the longest line formed by the combination of the tooling structure model and the bottom plane model, and the line extends along the coordinate axes parallel to the global coordinate system. Then, the longest line is projected on the bottom plane, as shown in FIG. 1. The line is the horizontal line segment in the middle of the rectangular frame in FIG. 1. In this example, L = 30 m. The measurement station 7 needs to be set to cover all the measurement points 5 of the tooling structure 1 and cover the longest measurement line L. This step is used to determine the number of measurement equipments that meet the measurement requirement of covering the longest measurement line according to the ranging parameters of each measurement equipment.

[0052] In some optional embodiments, step S2 further includes:

[0053] Step S21, calculating the minimum number of measuring devices along the longest measuring line of the tooling measuring field according to the first ranging. The step calculates the minimum number of measuring devices n by the following formula:

[0054] n=ρ1*L / L1; where ρ1≥1.1 when σ≥0.1mm, and ρ1≥1.2 when σ<0.1mm, in the embodiment, σ=0.1mm, thus ρ1may be 1.1. Substituting the formula, n=2.53 is obtained.

[0055] Step S22, correcting the minimum number of measuring devices based on the given repositioning error. In some optional embodiments, in step S22, the correction coefficient ρ2=(σ1+σ) / σ, where σ1is the repositioning error, and σ is the tooling required accuracy, for example, the given σ=0.1mm, the repositioning error σ1is initially given, for example, σ1=0.02mm. Thus, the correction coefficient ρ2=1.2 is obtained, and then the minimum number of measuring devices is corrected, the corrected minimum number of measuring devices n1=ρ2*n=1.2*2.53=2.79.

[0056] Step S23, rounding up the corrected minimum number of measuring devices to obtain the first number of measuring devices.

[0057] In this step, the first number of measuring devices n2=roundup(n1)=roundup(2.79)=3; where roundup is the rounding up function.

[0058] Step S3, correcting the first ranging according to the ratio of the minimum number of measuring stations to the first number of measuring devices to obtain the second ranging.

[0059] It can be understood that, since the first number of measuring devices changes relative to the minimum number of measuring devices in step S2, the first ranging must change, that is, according to the condition that the longest measuring line does not change, the more the number of measuring devices, the smaller the maximum ranging size can be. In this step, the first ranging L1is corrected according to the ratio relationship change of n=2.33 to n2=3, and the final rounding second ranging L2=L1*n / n2=14.16*2.33 / 3=11m is obtained.

[0060] Step S4, distributing the measuring devices in the measuring field according to the first number of measuring devices, so that the measuring devices maximumly envelope the measuring points of each tooling structure.

[0061] In this step, according to the coordinate axis close to the global coordinate system of the measuring system and maximumly envelopes the measuring points 5 of the tooling structure, the distribution is carried out within the range of L=30m of the longest measuring line according to n2=3; that is, three measuring devices are arranged according to the actual situation.

[0062] Step S5, correct the first number of measuring devices based on the distance between the measuring devices and the longest measuring line, and obtain a second number of measuring devices.

[0063] In this step, since the measuring devices arranged in step S4 are not necessarily located completely on the longest measuring line, it is possible that they are located at a distance from the longest measuring line, so that the first number of measuring devices determined in step S2 cannot completely cover the longest measuring line, and therefore this step needs to correct the first number of measuring devices.

[0064] In some optional embodiments, step S5 further comprises:

[0065] Step S51, determine the vertical distance between the measuring devices and the longest measuring line according to the positions of the actually arranged measuring devices; referring to FIG. 1, it is assumed that the vertical distance L3 is 4 m.

[0066] Step S52, calculate a deviation correction coefficient according to the vertical distance and the second distance; in this step, the deviation correction coefficient ρ2 = 2*[L3 2 +(L2 / 2) 2 ] 1 / 2 / L2, and substituting the parameters can obtain the deviation correction coefficient ρ2 = 1.23.

[0067] Step S53, correct the first number of measuring devices according to the deviation correction coefficient, and form the second number of measuring devices after rounding up. In this step, the second number of devices n3 = roundup(ρ2*n2), and substituting the parameters can obtain the second number of devices n3 = 4.

[0068] As can be seen, step S5 corrects the number of measuring devices from 3 to 4, and as shown in FIG. 1, the four circles respectively represent the measurement coverage ranges of the four measuring devices.

[0069] Step S6, correct the second distance according to the ratio of the first number of measuring devices to the second number of measuring devices, and obtain a third distance.

[0070] This step has the same principle as step S3, and since the number of measuring devices has changed, the maximum distance can be further reduced. In this step, the second distance L2 is corrected according to the ratio relationship change from n2 = 3 to n3 = 4, and finally the third distance L4 = L2*n2 / n3 = 11*3 / 4 = 8.25 m after rounding up.

[0071] Step S7, calculate a first continuity interval of the datum points on the longest measuring line according to the third distance and the tooling requirement accuracy, and calculate a second continuity interval of the datum points on the longest measuring line according to the third distance and the actual distance accuracy corresponding thereto.

[0072] In this step, after the third distance is calculated, the layout of the system reference points on the longest measuring line needs to be performed, and step S7 is used to calculate the interval of the continuously laid system reference points.

[0073] In some optional embodiments, step S7 further comprises:

[0074] The first continuity interval C1 is calculated according to the following formula:

[0075] C1 = 2.5 * σ * L3; C1 = 2.5 * 0.1 * 8.25 = 2.06 m is calculated by substituting the parameters.

[0076] The second continuity interval C2 is calculated according to the following formula: C2 = 40 * (σ - σ2) + 0.8;

[0077] Wherein, σ is the tooling requirement accuracy, σ2 is the actual distance accuracy corresponding to the third distance L4. The formula for calculating σ2 is the distance accuracy formula, which has been described in step S1: distance accuracy = distance constant + distance coefficient * distance. After substituting the third distance L4, σ2 = 15 μm + 6 μm * L4 = 15 μm + 6 μm * 8.25 = 0.0645 mm. Then substitute it into the second continuity interval C2 formula to get C2 = 40 * (0.1 - 0.0645) + 0.8 = 2.22 m.

[0078] In some optional embodiments, further comprising boundary limiting the second continuity interval C2:

[0079] When C2 < 0.3 m, C2 is modified to 0.3 m; when the longest distance line length L < 5 m and C2 > 0.8 m, C2 is modified to 0.8 m; when 5 m ≤ L < 10 m and C2 > 1.4 m, C2 is modified to 1.4 m; when L ≥ 10 m and C2 > 5 m, C2 is modified to 5 m.

[0080] In this embodiment, since the longest distance line length L = 30, C2 = 2.22 m, the boundary value limiting condition is not involved, and finally C2 is still 2.22 m.

[0081] Step S8, according to the longest measuring line, the first continuity interval and the second continuity interval are operated to obtain the third continuity interval, and the layout of the system reference points on the longest measuring line is completed according to the third continuity interval.

[0082] In some optional embodiments, step S8 further comprises:

[0083] When L ≤ 10 m, the third continuity interval C3 is set to: C3 ≤ min (C1, C2);

[0084] When 10 < L ≤ 20 m, the third continuity spacing C3 is set as: C3 ≤ (C1 + C2) / 2;

[0085] When L > 20 m, the third continuity spacing C3 is set as: C3 ≤ max(C1, C2).

[0086] In the embodiment, since L = 30 m > 20 m, C3 ≤ max(C1, C2) = max(2.06, 2.22) = 2.22 m, that is, the spacing between the system building reference points 2 on the longest measuring line in FIG. 1 cannot exceed 2.22 m.

[0087] In some optional embodiments, step S8 is further followed by:

[0088] Step S9, determining the arrangement spacing C4 of the system expanding reference points according to the third continuity spacing C3 and the longest measuring line L: C4 ≤ min(2 * C3, L / 5); in this example, C4 ≤ min(2 * 2.22, 30 / 5) = 4.44 m.

[0089] Step S10, determining the arrangement spacing C5 of the stable reference points according to the longest measuring line L: C5 ≤ min(5 m, L / 3); in this example, C5 ≤ min(5, 30 / 3) = 5 m.

[0090] According to the above calculation, the upper limit thresholds of the continuity design in the 30 m tool measuring field embodiment can be obtained, the system building reference point arrangement spacing C3 ≤ 2.22 m, the system expanding reference point arrangement spacing C4 ≤ 4.44 m, and the stable reference point arrangement spacing C5 ≤ 5 m. In the actual arrangement of the system building reference points, the system expanding reference points, and the stable reference points, the arrangement spacing is downward compatible according to the specific structure of the tool and the limited value.

[0091] The above merely provides a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical range disclosed by the present application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A target accuracy based large scale measurement field continuity design method, characterized in that, The method comprises the following steps: Step S1, calculating a first ranging according to the ranging accuracy parameter of the measuring device under the tooling requirement accuracy; Step S2, determining the minimum number of measuring devices according to the first ranging, and correcting it to obtain the first number of measuring devices; Step S3, correcting the first ranging according to the ratio of the minimum number of measuring devices to the first number of measuring devices to obtain the second ranging; Step S4, distributing the measuring devices according to the first number of measuring devices in the measuring field to maximize the envelope of the measuring points of each tooling structure; Step S5, correcting the first number of measuring devices based on the distance between the measuring device and the longest measuring line to obtain the second number of measuring devices; Step S6, correcting the second ranging according to the ratio of the first number of measuring devices to the second number of measuring devices to obtain the third ranging; Step S7, calculating the first continuity interval of the system reference point on the longest measuring line according to the third ranging and the tooling requirement accuracy, and calculating the second continuity interval of the system reference point on the longest measuring line according to the third ranging and the actual ranging accuracy corresponding thereto; Step S8, calculating the third continuity interval according to the first continuity interval and the second continuity interval on the longest measuring line, and completing the layout of the system reference point on the longest measuring line according to the third continuity interval.

2. The target accuracy based large size measurement field continuity design method of claim 1, wherein, Step S2 further comprises: Step S21, calculating the minimum number of measuring devices along the longest measuring line of the tooling measuring field according to the first ranging; Step S22, correcting the minimum number of measuring devices based on the given stationing error; Step S23, rounding up the corrected minimum number of measuring devices to obtain the first number of measuring devices.

3. The target accuracy based large size measurement field continuity design method of claim 2, wherein, In step S22, the correction coefficient ρ2=(σ1+σ) / σ, wherein σ1 is the stationing error and σ is the tooling requirement accuracy.

4. The target accuracy based large size measurement field continuity design method of claim 1, wherein, Step S5 further comprises: Step S51, determining the vertical distance between the measuring device and the longest measuring line according to the position of the actually arranged measuring device; Step S52, calculating the deviation correction coefficient according to the vertical distance and the second ranging; Step S53, correcting the first number of measuring devices according to the deviation correction coefficient and rounding up to form the second number of measuring devices.

5. The target accuracy based large size measurement field continuity design method as claimed in claim 1, wherein, Step S7 further comprises: The first continuity interval C1 is calculated according to the following formula: C1=2.5*σ*L4; The second continuity interval C2 is calculated according to the following formula: C2=40*(σ-σ2)+0.8; Wherein, σ is the tooling requirement accuracy, and σ2 is the actual ranging accuracy corresponding to the third ranging L4.

6. The target accuracy based large size measurement field continuity design method of claim 5, wherein, Further comprising boundary limitation of the second continuity interval C2: When C2<0.3m, C2 is modified to 0.3m; when the length of the longest measuring line L<5m and C2>0.8m, C2 is modified to 0.8m; when 5m≤L<10m and C2>1.4m, C2 is modified to 1.4m; when L≥10m and C2>5m, C2 is modified to 5m.

7. The target accuracy based large size measurement field continuity design method as claimed in claim 5, wherein, Step S8 further comprises: When L≤10m, the third continuity interval C3 is set as: C3≤min(C1,C2); When 10 < L≤ 20 m, the third continuity spacing C3 is set as: C3≤(c1+c2) / 2; When L > 20 m, the third continuity spacing C3 is set as: C3≤max(C1, C2).

8. The target accuracy based large size measurement field continuity design method as claimed in claim 1, wherein, Step S8 is further followed by: Step S9, determining the arrangement spacing C4 of the extended reference point according to the third continuity spacing C3 and the longest measuring line L: C4≤min(2*C3, L / 5); Step S10, determining the arrangement spacing C5 of the stable reference point according to the longest measuring line L: C5≤min(5m, L / 3).

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