A method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection

Abstract

The present invention relates to a method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection, comprising the following steps: utilizing the self-collimation principle of theodolite, using a right-angle prism to lead out the non-linear guide rail reference plane, completing the calibration between the non-linear splicing instrument Y-axis slider and the non-linear splicing instrument Y-axis reference plane, and determining the position of the lowest reference point of the non-linear guide rail; using an optical straightedge to align the non-linear splicing instrument body, and reading the position of the mark point observed in the microscope lens; and obtaining the root mean square value of the actual spatial position of the non-linear splicing instrument microscope lens working point through calculation and analysis. The calibration method of the present invention, which detects the accuracy of the splicing instrument and calibrates the spatial position based on an optical straightedge, is not only applicable to linear motion, but also solves the problem of accuracy detection and spatial position calibration of the non-linear splicing instrument, and the calibration detection operation is convenient and the cycle is short. Calibration can be performed before each focal plane splicing, effectively improving the efficiency of instrument accuracy calibration.

Description

Technical Field

[0001] The present invention relates to the technical field of focal plane development of aerospace optical remote sensing cameras, and in particular to a method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection. Background Art

[0002] With the rapid and multifaceted development of space optical remote sensing technology, the development of wide-field-of-view, high-resolution space optical camera payloads has become a research priority. The size of a single CCD sensor is no longer sufficient for large-field-of-view space camera development, necessitating the splicing of multiple CCDs to create an equivalent large-scale focal plane. Therefore, the development of large-scale focal planes has become a key technology in the development of space remote sensing cameras. CDD stitching has emerged as a specialized technique that effectively meets the wide-field-of-view requirements of space cameras. A crucial prerequisite for achieving large-scale focal plane stitching is the development of a dedicated CCD stitching device capable of high-precision three-dimensional motion. The motion accuracy of this device sets the benchmark for the overall focal plane stitching accuracy. Currently, dual-frequency laser interferometers are commonly used for precision testing of high-precision three-dimensional motion stages. This method enables three-axis linearity, positioning accuracy, and repeatability testing. For complex space camera optical systems with non-planar focal planes, a non-linear guide stitching instrument is required to accomplish this large-scale non-planar focal plane stitching. Therefore, the precision and benchmark testing of the non-linear guide stitching instrument are crucial for ensuring the accuracy of non-planar focal plane development. Summary of the Invention

[0003] In view of this, the present invention provides a method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection.

[0004] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0005] A non-linear guide rail splicing instrument accuracy and spatial position calibration method based on optical straight ruler detection, the non-linear guide rail splicing instrument applicable to the calibration method includes: a non-linear splicing instrument body;

[0006] A non-linear guide rail is provided on the non-linear splicing instrument body; a microscope lens and a reference cubic prism are provided in the middle of the non-linear guide rail, a right-angle prism is provided at one end of the non-linear guide rail; a theodolite is provided in the direction of the line connecting the reference cubic prism and the right-angle prism;

[0007] The non-linear stitching instrument is provided with two marble support structures; each marble support structure is provided with an optical adjustment platform; an optical straight ruler is mounted on the two optical adjustment platforms;

[0008] The Y-axis of the non-linear stitching machine is the length direction of the non-linear guide rail, the X-axis of the non-linear stitching machine is the horizontal direction perpendicular to the Y-axis of the non-linear stitching machine, and the Z-axis of the non-linear stitching machine is the vertical direction;

[0009] The calibration method includes the following steps:

[0010] Step 1: Using the theodolite autocollimation principle, use a right-angle prism to draw out the non-linear guide rail reference surface, and complete the calibration between the non-linear splicing instrument Y-axis slider and the non-linear splicing instrument Y-axis reference surface to determine the position of the non-linear guide rail's lowest reference point;

[0011] Step 2: Use an optical straightedge to align the non-linear stitching instrument and read the position of the mark point observed in the microscope lens;

[0012] Step 3: Obtain the root mean square value of the actual spatial position of the working point of the microscope lens of the non-linear stitching instrument through calculation and analysis.

[0013] In the above technical solution, after step 3, there is a further step:

[0014] Step 4: Calculate the root mean square value of the Y-axis positioning accuracy of the non-linear stitching instrument by collecting the positions of the optical straightedge mark points multiple times.

[0015] In the above technical solution, step 1 is specifically as follows:

[0016] The reference cubic prism is glued and fixed to the side of the Y-axis slider of the non-linear stitching instrument, the right-angle prism is placed on the non-linear guide rail reference surface, the non-linear guide rail reference surface is led out, and the theodolite is set on the side of the non-linear stitching instrument. The reference cubic prism and the right-angle prism reference surface are observed simultaneously in the field of view of the theodolite. The azimuth angle of the right-angle prism is adjusted so that the crosshairs reflected by the reference cubic prism and the right-angle prism appear in the field of view at the same time. The position of the Y-axis slider of the non-linear stitching instrument is adjusted. When the pitch values ​​of the two crosshairs are observed to be completely consistent in the field of view of the theodolite, the position of the non-linear guide rail at this time is recorded, which is the lowest reference point of the non-linear guide rail.

[0017] In the above technical solution, step 2 is specifically as follows:

[0018] Adjust the Y-axis of the non-linear stitching instrument to the lowest reference point position, adjust the Z-axis of the non-linear stitching instrument until the microscope lens observes the mark points clearly and aligned, then adjust the Y-axis position of the non-linear stitching instrument to the left and right sides, respectively adjust the Z-axis position of the stitching instrument and the optical adjustment tables on both sides to the symmetrical positions on the left and right sides of the Y-axis of the non-linear stitching instrument so that the microscope lens observes the mark points clearly, and at the same time ensure that the Z-axis adjustment amount of the non-linear stitching instrument is consistent when observing the positions of each symmetrical mark point;

[0019] Determine two points symmetrically on the optical straight ruler. When the mark point at the lowest reference point on the Y axis of the non-linear stitching instrument is clearly observed, the spatial working position of the microscope lens is:

[0020]

[0021] Where: X is the number of marks between the selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument;

[0022] R0 is the spatial working position of the microscope head;

[0023] L0 is the distance between two marking points on the optical ruler;

[0024] θ is the corresponding angle value of the non-linear stitching instrument Y axis from the lowest reference point position of the non-linear stitching instrument Y axis to the selected target mark point.

[0025] In the above technical solution, in step 3, the root mean square value of the actual spatial position of the microscope lens working point satisfies:

[0026]

[0027] Where: X i The number of marks between the i-th selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument;

[0028] R RMS is the root mean square value of the actual spatial position of the microscope lens working point;

[0029] L0 is the distance between two marking points on the optical ruler;

[0030] θ i The i-th calibration is performed on the non-linear stitching instrument Y-axis corresponding angle value from the position of the lowest reference point of the non-linear stitching instrument Y-axis to the selected target mark point. The value range of the number of sampling points i is greater than or equal to 6.

[0031] In the above technical solution, step 4 is specifically as follows:

[0032] Operate the non-linear stitching instrument to repeatedly locate the marking points on the optical straight ruler;

[0033] The Y-axis position of the non-linear splicing instrument at each marking point is obtained by analysis and calculation:

[0034]

[0035] Where: i 实测 The calculated value of the corresponding angle value of the non-linear stitching instrument Y axis between the lowest reference point position of the non-linear stitching instrument Y axis and the selected target mark point for the i-th calibration;

[0036] X i The number of marks between the i-th selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument;

[0037] L0 is the distance between two marking points on the optical ruler;

[0038] RRMS is the spatial working point position of the microscope lens obtained by calibration;

[0039] The Y-axis positioning accuracy of the non-linear splicing instrument is:

[0040]

[0041] Where: Δθ is the Y-axis positioning accuracy of the non-linear splicing instrument;

[0042] θ i理论 The reading value of the Y-axis grating scale of the non-linear splicing instrument;

[0043] After obtaining the positioning accuracy data of each group, the root mean square value is obtained:

[0044]

[0045] Where: Δθ iRMS The root mean square value of the spatial working point position of the microscope lens obtained by calibration is the value range of the number of sampling points i which is greater than or equal to 6.

[0046] The present invention has the following beneficial effects:

[0047] The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection of the present invention uses an optical straightedge to detect the accuracy of the splicing instrument and calibrate the spatial position. It is not only suitable for linear motion, but also solves the problems of accuracy detection and spatial position calibration of non-linear splicing instruments. The calibration detection operation is convenient and the cycle is short. Calibration can be performed before each focal plane splicing, effectively improving the efficiency of instrument accuracy calibration.

[0048] The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection of the present invention has been applied in the XX-1 high-resolution optical payload project, completing the accuracy detection and spatial position calibration of the non-linear splicing instrument and solving the problem of large-scale non-planar focal plane splicing. Currently, all load indicators are tested normally, effectively proving the correctness and rationality of this method. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Figure 1 This is a schematic diagram of the calibration of the lowest reference position of the Y-axis of the non-linear stitching instrument.

[0051] Figure 2 Schematic diagram of the calibration of the spatial working position of the non-linear splicing instrument.

[0052] Figure 3 This is a schematic diagram of the marking points on an optical straightedge.

[0053] Figure 4Schematic diagram of the calibration analysis of the spatial working point position of the microscope lens of the non-linear stitching instrument.

[0054] The reference numerals in the figures indicate:

[0055] 1- Non-linear stitching instrument body; 2- Non-linear guide rail; 3- Microscope lens; 4- Reference cubic prism; 5- Right-angle prism; 6- Theodolite; 7- Optical straightedge; 8- Optical adjustment table; 9- Marble support structure. DETAILED DESCRIPTION

[0056] The inventive concept of the present invention is:

[0057] For the precision detection and reference calibration of non-linear guide rail splicing instruments, dual-frequency laser interferometers cannot meet the actual use requirements. The present invention adopts a high-precision optical straight ruler. On the basis of using a reference prism to calibrate the spatial reference position of the non-linear guide rail, the spatial position and precision calibration of the non-linear guide rail splicing instrument can be realized. Before each non-planar large-size focal plane splicing, this method can be used to calibrate the instrument precision to ensure the precision of the non-planar focal plane splicing.

[0058] The present invention discloses a method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection. The method utilizes the self-collimation principle of a theodolite, uses a right-angle prism to lead out the non-linear guide rail reference plane, completes calibration between the Y-axis slider of the non-linear splicing instrument and the Y-axis reference plane of the non-linear splicing instrument, and determines the position of the lowest reference point of the non-linear guide rail. On this basis, an optical straightedge is used to align the non-linear splicing instrument, reads the position of the mark point observed in the microscope lens, and obtains the root mean square value of the actual spatial position of the working point of the microscope lens of the non-linear splicing instrument through calculation and analysis, thereby completing the spatial position calibration of the non-linear splicing instrument. At the same time, by collecting the positions of the optical straightedge mark points multiple times, the root mean square value of the Y-axis positioning accuracy of the non-linear splicing instrument is calculated.

[0059] The present invention will be described in detail below with reference to the accompanying drawings.

[0060] The present invention is based on the optical level ruler detection non-linear guide rail splicing instrument precision and spatial position calibration method, the specific implementation device, such as Figure 1 and 2 As shown, it includes: a non-linear splicing instrument body 1, a non-linear guide rail 2, a microscope lens 3, a reference cubic prism 4, a right-angle prism 5, a theodolite 6, an optical straightedge 7, an optical adjustment table 8, and a marble support structure 9.

[0061] Specifically, a non-linear guide rail 2 is provided on the non-linear stitching instrument body 1; a microscope lens 3 and a reference cubic prism 4 are provided in the middle of the non-linear guide rail 2, and a right-angle prism 5 is provided at one end of the non-linear guide rail 2; a theodolite 6 is provided in the direction of the line connecting the reference cubic prism 4 and the right-angle prism 5; two marble support structures 9 are provided on the non-linear stitching instrument body 1; an optical adjustment platform 8 is provided on each marble support structure 9; and an optical straightedge 7 is mounted on the two optical adjustment platforms 8.

[0062] The Y axis of the non-linear stitching machine is the length direction of the non-linear guide rail 2, the X axis of the non-linear stitching machine is the horizontal direction perpendicular to the Y axis of the non-linear stitching machine, and the Z axis of the non-linear stitching machine is the vertical direction.

[0063] The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection of the present invention comprises the following steps:

[0064] Step 1: Using the theodolite autocollimation principle, use the right-angle prism 5 to draw out the reference plane of the non-linear guide rail 2, and complete the calibration between the Y-axis slider of the non-linear splicing instrument and the Y-axis reference plane of the non-linear splicing instrument to determine the position of the lowest reference point of the non-linear guide rail 2;

[0065] The accuracy calibration of the non-linear splicing instrument must first be carried out to calibrate the lowest reference point of the non-linear guide rail 2. Figure 1 As shown, the reference cubic prism 4 is bonded and fixed to the side of the Y-axis slider of the non-linear splicing instrument, the right-angle prism 5 is placed on the reference plane of the non-linear guide rail 2, the reference plane of the non-linear guide rail 2 is led out, and the theodolite 6 is set on the side of the non-linear splicing instrument. The reference planes of the reference cubic prism 4 and the right-angle prism 5 are observed at the same time in the field of view of the theodolite 6, and the azimuth angle of the right-angle prism 5 is adjusted so that the crosshairs reflected by the reference cubic prism 4 and the right-angle prism 5 appear in the field of view at the same time. The position of the Y-axis slider of the non-linear splicing instrument is adjusted. When the pitch values ​​of the two crosshairs are observed to be completely consistent in the field of view of the theodolite 6, the position of the non-linear guide rail 2 at this time is recorded, which is the Y-axis zero position of the non-linear splicing instrument, that is, the lowest reference point of the non-linear guide rail 2, thereby completing the position calibration of the lowest reference point of the non-linear guide rail 2.

[0066] Step 2: Use the optical straightedge 7 to align the non-linear stitching instrument body 1 and read the position of the mark point observed in the microscope lens 3;

[0067] After the lowest reference point position calibration of the non-linear guide rail 2 is completed, the spatial working position calibration of the non-linear stitching instrument microscope lens 3 is carried out. After the installation and debugging of the non-linear stitching instrument axes and the microscope lens 3 are completed, it is difficult to accurately control the spatial position of the working point of the microscope lens 3 due to the errors in the adjustment of the axes and the installation errors of the microscope lens 3. Figure 2As shown, two marble support structures 9 of equal height are placed on the table of the non-linear stitching instrument body 1, and two optical adjustment tables 8 are placed on the marble support structures 9 respectively, and an optical straight ruler 7 is placed on the optical adjustment table 8. The marking points on the working surface of the optical straight ruler 7 are engraved by photolithography. The specific marking points are as follows: Figure 3 As shown, all markers are depicted equidistantly, and the position accuracy between markers is better than

[0068] ±0.5μm, and the straightness of all marking points is better than 1μm. The spatial position calibration process of the working point of the microscope lens 3 of the non-linear stitching instrument is as follows: adjust the Y axis of the non-linear stitching instrument to the lowest reference point position, adjust the Z axis of the non-linear stitching instrument to the microscope lens 3 to observe the marking points clearly and aligned, and then adjust the Y axis position of the non-linear stitching instrument to the left and right sides, and adjust the Z axis position of the non-linear stitching instrument and the optical adjustment tables 8 on both sides to the symmetrical positions on the left and right sides of the non-linear stitching instrument Y axis respectively. The microscope lens 3 observes the marking points clearly, and at the same time ensures that the adjustment amount of the Z axis of the non-linear stitching instrument is consistent when observing the positions of each symmetrical marking point. At this time, the alignment work of the optical straight ruler 7 on the non-linear stitching instrument body 1 is completed, and two points are determined at symmetrical positions on the optical straight ruler 7, such as Figure 4 As shown, it can be calculated that when the observation mark point at the lowest reference point of the Y axis of the non-linear stitching instrument is clear, the spatial working position of the microscope head 3 is:

[0069]

[0070] Where: X: is the number of marks between the selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument;

[0071] R0 is the spatial working position of the microscope head 3;

[0072] L0 is the distance between two marking points on the optical straight ruler 7;

[0073] θ i For the i-th calibration, the corresponding angle value of the non-linear stitching instrument's Y-axis from the position of the non-linear stitching instrument's Y-axis lowest reference point to the selected target mark point. To ensure the accuracy and reliability of the calibration result, the number of points i must be greater than or equal to 6.

[0074] Step 3: Obtain the root mean square value of the actual spatial position of the working point of the microscope lens 3 of the non-linear stitching instrument through calculation and analysis;

[0075] There are certain errors in the development and processing of the non-linear guide rail 2. There is a certain degree of randomness in the selection of two symmetrical marking points on the optical straightedge 7 for the calculation of the spatial working point position marking of the non-linear splicing instrument microscope lens 3. In the actual marking process, multiple groups of data should be selected as much as possible, and multiple large-span calibrations should be performed. After obtaining each group of calibration data, the root mean square value of the final data is taken as the optimal calibration solution.

[0076]

[0077] Where: X i : is the number of marks between the i-th selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument;

[0078] R RMS is the RMS value of the actual spatial position of the working point of the microscope lens 3;

[0079] R i : The spatial position of the working point of the microscope lens 3 obtained by completing the calibration of a single set of data for the i-th time;

[0080] L0: The distance between two marking points on the optical ruler 7;

[0081] θ i : The corresponding angle value of the non-linear stitching instrument's Y-axis from the lowest reference point of the non-linear stitching instrument to the selected target mark point for the i-th calibration. To ensure the accuracy and reliability of the calibration results, the number of points collected i must be greater than or equal to 6.

[0082] Record the Z-axis position of the non-linear stitching instrument at the lowest reference mark point of the Y-axis of the non-linear stitching instrument. This position is the spatial working point position R0 of the microscope lens 3 of the non-linear stitching instrument. On this basis, combined with the design value of the spatial position of the non-planar focal plane, determine the corresponding Z-axis position of the non-linear stitching instrument for the non-planar focal plane stitching reference, and set it as the corresponding Z-axis zero position of the non-linear stitching instrument. Each time the stitching work is performed, the stitching instrument can be operated to complete the return to zero for precision calibration. At this point, the calibration of the spatial working point position of the microscope lens 3 of the non-linear stitching instrument is completed.

[0083] Step 4: Calculate the root mean square value of the Y-axis positioning accuracy of the non-linear stitching instrument by collecting the positions of the 7 marking points of the optical straight ruler multiple times;

[0084] The non-linear stitching instrument is operated to repeatedly locate the marking points on the optical straight ruler 7, and the positioning accuracy index of the instrument can be analyzed and calculated.

[0085] The Y-axis position of the non-linear splicing instrument at each marking point is obtained by analysis and calculation:

[0086]

[0087] Where: θ i实测 : The calculated value of the corresponding angle value of the non-linear stitching instrument Y axis between the lowest reference point position of the non-linear stitching instrument Y axis and the selected target mark point for the i-th calibration;

[0088] X i : is the number of marks between the i-th selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument;

[0089] L0: The distance between two marking points on the optical ruler 7;

[0090] R RMS : is the root mean square value of the spatial position of the working point of the microscope lens 3, that is, the actual spatial position of the working point of the microscope lens 3 obtained after completing the above multiple sets of calibration;

[0091] The Y-axis positioning accuracy of the non-linear splicing instrument is:

[0092]

[0093] Where: Δθ i : Y-axis positioning accuracy of the non-linear splicing instrument;

[0094] θ i理论 : It is the reading value of the Y-axis grating ruler of the non-linear splicing instrument;

[0095] After obtaining the positioning accuracy data of each group, take the final data RMS value as the final value:

[0096]

[0097] Where: Δθ iRMS is the root mean square value of the spatial working point position of the microscope lens 3 obtained by calibration. To ensure the accuracy and reliability of the calibration result, the number of sampling points i must be greater than or equal to 6.

[0098] The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection of the present invention uses an optical straightedge to detect the accuracy of the splicing instrument and calibrate the spatial position. It is not only suitable for linear motion, but also solves the problems of accuracy detection and spatial position calibration of non-linear splicing instruments. The calibration detection operation is convenient and the cycle is short. Calibration can be performed before each focal plane splicing, effectively improving the efficiency of instrument accuracy calibration.

[0099] The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection of the present invention has been applied in the XX-1 high-resolution optical payload project, completing the accuracy detection and spatial position calibration of the non-linear splicing instrument and solving the problem of large-scale non-planar focal plane splicing. Currently, all load indicators are tested normally, effectively proving the correctness and rationality of this method.

[0100] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection, characterized in that: The non-linear guide rail splicing instrument applicable to the calibration method comprises: a non-linear guide rail splicing instrument body (1); A non-linear guide rail (2) is provided on a non-linear splicing instrument body (1); a microscope lens (3) and a reference cubic prism (4) are provided in the middle of the non-linear guide rail (2); a right-angle prism (5) is provided at one end of the non-linear guide rail (2); and a theodolite (6) is provided in the direction of the line connecting the reference cubic prism (4) and the right-angle prism (5); Two marble support structures (9) are provided on a non-linear splicing instrument body (1); an optical adjustment platform (8) is provided on each marble support structure (9); and an optical straightedge (7) is mounted on the two optical adjustment platforms (8); The non-linear stitching apparatus Y axis is the length direction of the non-linear guide rail (2), the non-linear stitching apparatus X axis is the horizontal direction perpendicular to the non-linear stitching apparatus Y axis, and the non-linear stitching apparatus Z axis is the vertical direction; The calibration method includes the following steps: Step 1: Using the self-collimation principle of theodolite, use a right-angle prism (5) to draw out the reference plane of the non-linear guide rail (2), and complete the calibration between the Y-axis slider of the non-linear splicing instrument and the Y-axis reference plane of the non-linear splicing instrument to determine the lowest reference point position of the non-linear guide rail (2); Step 2: Use an optical straightedge (7) to align the non-linear stitching instrument body (1) and read the position of the mark point observed in the microscope lens (3); Step 3: Obtain the root mean square value of the actual spatial position of the working point of the non-linear stitching instrument microscope lens (3) through calculation and analysis.

2. The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection according to claim 1 is characterized in that: After step 3, there are the following steps: Step 4: By collecting the positions of the marking points of the optical straightedge (7) multiple times, the root mean square value of the Y-axis positioning accuracy of the non-linear splicing instrument is calculated.

3. The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection according to claim 1 or 2, characterized in that: Step 1 is as follows: The reference cubic prism (4) is bonded and fixed on the side of the Y-axis slider of the non-linear splicing instrument, the right-angle prism (5) is placed on the reference surface of the non-linear guide rail (2), the reference surface of the non-linear guide rail (2) is drawn out, the theodolite (6) is set on the side of the non-linear splicing instrument, the reference surfaces of the reference cubic prism (4) and the right-angle prism (5) are observed simultaneously in the field of view of the theodolite (6), the azimuth angle of the right-angle prism (5) is adjusted, and the crosshairs reflected by the reference cubic prism (4) and the right-angle prism (5) appear in the field of view at the same time, the position of the Y-axis slider of the non-linear splicing instrument is adjusted, and when the pitch values ​​of the two crosshairs are observed to be completely consistent in the field of view of the theodolite (6), the position of the non-linear guide rail (2) at this time is recorded, which is the lowest reference point of the non-linear guide rail (2).

4. The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection according to claim 1 or 2, characterized in that: Step 2 is as follows: Adjust the Y axis of the non-linear stitching instrument to the lowest reference point position, adjust the Z axis of the non-linear stitching instrument to the microscope lens (3) to observe the mark points clearly and aligned, then adjust the Y axis position of the non-linear stitching instrument to the left and right sides, respectively adjust the Z axis position of the non-linear stitching instrument and the optical adjustment tables (8) on both sides to the symmetrical positions on the left and right sides of the Y axis of the non-linear stitching instrument, and observe the mark points clearly with the microscope lens (3), and at the same time ensure that the Z axis adjustment amount of the non-linear stitching instrument is consistent when observing the positions of the symmetrical mark points; Two points are determined at symmetrical positions on the optical straight ruler (7). When the observation mark point at the lowest reference point of the Y axis of the non-linear splicing instrument is clear, the spatial working position of the microscope head (3) is: Where: X is the number of marks between the selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument; R0 is the spatial working position of the microscope head (3); L0 is the distance between two marking points on the optical straight ruler (7); θ is the corresponding angle value of the non-linear stitching instrument Y axis from the lowest reference point position of the non-linear stitching instrument Y axis to the selected target mark point.

5. The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection according to claim 1 or 2, characterized in that: In step 3, the root mean square value of the actual spatial position of the working point of the microscope lens (3) satisfies: Where: X i The number of marks between the i-th selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument; R RMS is the root mean square value of the actual spatial position of the working point of the microscope lens (3); L0 is the distance between two marking points on the optical straight ruler (7); θ i The i-th calibration is performed on the non-linear stitching instrument Y-axis corresponding angle value from the position of the lowest reference point of the non-linear stitching instrument Y-axis to the selected target mark point. The value range of the number of sampling points i is greater than or equal to 6.

6. The method for calibrating the accuracy and spatial position of a non-linear guide rail splicing instrument based on optical straightedge detection according to claim 2, characterized in that: Step 4 is as follows: Operate the non-linear splicing instrument to repeatedly locate each marking point on the optical straight ruler (7); The Y-axis position of the non-linear splicing instrument at each marking point is obtained by analysis and calculation: Where: i 实测 The calculated value of the corresponding angle value of the non-linear stitching instrument Y axis between the lowest reference point position of the non-linear stitching instrument Y axis and the selected target mark point for the i-th calibration; X i The number of marks between the i-th selected mark point and the lowest reference mark point on the Y axis of the non-linear splicing instrument; L0 is the distance between two marking points on the optical straight ruler (7); R RMS The spatial working point position of the microscope lens (3) obtained by calibration; the Y-axis positioning accuracy of the non-linear splicing instrument is: Where: Δθ i Y-axis positioning accuracy of the non-linear splicing instrument; θ i理论 The reading value of the Y-axis grating scale of the non-linear splicing instrument; After obtaining the positioning accuracy data of each group, the root mean square value is obtained: Where: Δθ iRMS The root mean square value of the spatial working point position of the microscope lens (3) obtained by calibration, the value range of the number of sampling points i is greater than or equal to 6.

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