Method for transferring an optical reference to a mechanical reference

Abstract

The present application relates to the field of optical technology, and more particularly to a kind of optical reference and mechanical reference transmission method, including setting three positioning points of optical element, three positioning points are unified in same coordinate system with mirror surface figure data;Mechanical adjustment platform is stepped along its own adjustment x direction by predetermined distance, and the movement model of optical element tool following mechanical adjustment frame under coordinate system is established.The change of positioning point is calculated by the six-dimensional adjustment amount required by optical element, and finally the required adjustment amount of mechanical adjustment platform is calculated by positioning point transformation, to complete the conversion from optical adjustment amount to mechanical adjustment amount.Through this method, the three positioning points set in the optical element tool are repeatedly measured during adjustment process, the current optical axis direction of mirror surface and the spatial pose state of mirror surface can be obtained, the adjustment direction and adjustment amount during adjustment process are guided, the adjustment accuracy is improved, the adjustment difficulty is reduced, and the unmanned adjustment is promoted.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a method for transferring optical and mechanical references. Background Technology

[0002] The demand for high-precision imaging quality has led to the adoption of asymmetric optical structures using complex curved surfaces such as freeform surfaces and aspherical surfaces as the primary choice for optical architecture. This also presents challenges to the integration technology of optical systems. Currently, the level of integration and adjustment of optical systems has become a key factor limiting the final imaging capability of the system.

[0003] In particular, mounting errors of optical components can cause a discrepancy between the spatial coordinates of the optical component and the spatial orientation of the mechanical fixture it is connected to. This results in a slight tilt of the component relative to the fixture, leading to persistent systematic errors during the assembly and adjustment process. The adjustment amount calculated by the algorithm is based on the designed orientation of the optical component. However, the adjustment direction of the mechanical adjustment frame exists in its own coordinate system, which is inconsistent with the required adjustment direction of the optical component. Furthermore, due to the different centers of rotation, changes in the spatial orientation of the component caused by the mechanical adjustment frame rotating the optical component can lead to a deviation of the component's center from the design origin. Therefore, correcting the mounting errors of the optical components and calculating the conversion relationship between optical and mechanical adjustment amounts are necessary prerequisites for ensuring the assembly and adjustment accuracy of the optical system and achieving automated assembly and adjustment. Summary of the Invention

[0004] This invention provides a method for transferring optical and mechanical references. It involves defining a spatial coordinate system for the detection optical path, measuring the spatial coordinates of each point in a camera-plane mirror optical detection system, measuring the changes in spatial coordinates before and after the adjustment stage displacement, and establishing a mechanical adjustment coordinate system with the adjustment stage's motion center as the origin through coordinate mapping. By measuring the surface shape data of the adjustment mirror and the spatial coordinate data of the positioning points in the measurement coordinate system, the tilt error caused by the mounting of optical components is analyzed and corrected to obtain the optical axis direction of the mirror. An optical adjustment coordinate system is then established between the mirror optical axis and the tooling. Finally, the optical and mechanical adjustment coordinate systems are linked through the positioning points to obtain an adjustment model in a global coordinate system.

[0005] This invention provides a method for transferring optical and mechanical references, comprising: Step 10: Set three positioning points for the optical element and unify the three positioning points with the mirror surface shape data in the same coordinate system; Step 20: Obtain the spatial orientation of the optical element, move the mechanical assembly table a predetermined distance along its own assembly x-direction, and measure the spatial coordinates of the three positioning points after the movement. Step 30: Process the spatial orientation of the optical element and the spatial coordinate data of the three positioning points after the movement to obtain the spatial relationship between the mirror vertex and the positioning point, and establish an optical adjustment coordinate system with the mirror vertex as the origin and the optical axis as the coordinate system, and calculate the spatial coordinates of the positioning point in the coordinate system. Step 40: Repeat step 20 multiple times in the six-dimensional direction to obtain the displacement coordinate change data of the mechanical assembly table in the coordinate system; Based on the rotation data in three directions, a three-layer concentric spherical model from the positioning point to the motion center of the mechanical assembly table is established. The spatial coordinates of the motion center of the mechanical assembly table in the coordinate system of the laser tracker are obtained. Based on the three translation data, the spatial coordinate changes of the motion center along the three coordinate axes are obtained, and the motion direction of the mechanical assembly table in the coordinate system is obtained. Establish a motion model of the mechanical assembly in the coordinate system, calculate the rotation matrix and translation vector of the tooling by the coordinate changes of the three positioning points, and inversely calculate the change parameters of the mechanical assembly platform. Step 50: By mapping the coordinates of the three positioning points in the optical adjustment coordinate system and the mechanical adjustment coordinate system, establish the motion relationship between the vertex of the optical element mirror and the motion center of the mechanical assembly table; convert the six-dimensional optical adjustment quantity into the coordinate transformation of the three positioning points through quaternion transformation, map the transformed three coordinates to the coordinate system of the laser tracker, calculate the new rotation matrix and translation vector, and then obtain the adjustment parameters of the mechanical assembly table, thus completing the conversion of the mechanical adjustment quantity.

[0006] According to the optical reference and mechanical reference transfer method provided by the present invention, step 30, the processing of the spatial position and orientation of the optical element and the spatial coordinate data of the three positioning points after movement includes: The spatial coordinate data of the three positioning points obtained in step 20 after the movement are processed to establish the spatial relationship between the mirror surface shape data and the mirror surface shape data in step 10, and to obtain the direction of the mirror optical axis.

[0007] According to the optical reference and mechanical reference transfer method provided by the present invention, in step 30, the processing of the spatial coordinate data of the three positioning points after movement obtained in step 20 specifically includes: using the Zernike fitting method to analyze the piston and tilt data of the mirror surface shape, so as to establish the spatial relationship between the mirror surface shape data and the mirror surface shape data in step 10, and obtain the direction of the mirror optical axis.

[0008] According to the optical reference and mechanical reference transfer method provided by the present invention, in step 20, the optical element fixture is installed on the mechanical assembly table, and the overall assembly structure is fixed on the camera lens frame. The mechanical assembly table is kept stationary, and the spatial coordinates of the measurement positioning point in the laser tracker measurement coordinate system are taken as the original position. According to the adjustment data of the mechanical assembly table, the mechanical assembly table is controlled to move a fixed distance in the X-axis, Y-axis and Z-axis directions respectively to obtain the spatial data of the three positioning points after the movement.

[0009] According to the optical reference and mechanical reference transfer method provided by the present invention, in step 40, the mechanical assembly table is rotated by fixed angles around the X, Y and Z axes to obtain the spatial coordinate data of the three positioning points rotating around the mechanical assembly motion center.

[0010] According to the optical and mechanical reference transfer method provided by the present invention, two directional point ball seats are set vertically on the camera lens frame, and the collected data are used as directional points for establishing a coordinate system.

[0011] According to the optical reference and mechanical reference transfer method provided by the present invention, in step 40, since the positioning point on the optical element tooling is fixed and its distance from the motion center of the mechanical assembly platform remains unchanged, the trajectory left by the mechanical assembly platform driving the three positioning points to rotate around the motion center can be fitted into a three-layer concentric sphere model. The sphere center coordinates are obtained by using the spatial coordinate data of the positioning points to perform spherical fitting.

[0012] According to the optical reference and mechanical reference transfer method provided by the present invention, in step 40, step 20 is repeated six times in a six-dimensional direction.

[0013] According to the optical and mechanical reference transfer method provided by the present invention, step 50, calculating the tooling rotation matrix and translation vector through the coordinate changes of three positioning points, specifically includes: The rotation matrix and translation vector of the mechanical adjustment model around the motion center are calculated by changing the coordinates of the three positioning points. The adjustment amount of the mechanical assembly platform is then calculated by Euler angle transformation.

[0014] According to the optical reference and mechanical reference transfer method provided by the present invention, in step 50, the six-dimensional optical adjustment amount includes translation adjustment amount and rotation adjustment amount, wherein the translation adjustment amount is converted into vector form, and the rotation adjustment amount is converted into a rotation matrix through quaternions.

[0015] The optical and mechanical reference transfer method provided by this invention, according to an embodiment of the invention, involves setting three positioning points on an optical element and unifying these three positioning points with the mirror surface shape data in the same coordinate system to obtain the spatial orientation of the optical element. The mechanical assembly stage is then moved a predetermined distance along its own x-axis, and the spatial coordinates of the three positioning points after the movement are measured again. After data processing, the motion center of the mechanical adjustment frame and the spatial coordinates and motion directions of each coordinate axis in the coordinate system are calculated. A motion model of the optical element tooling following the mechanical adjustment frame in the coordinate system is established. The six-dimensional adjustment amount of the mechanical adjustment frame is calculated by inversely using the changes in the spatial coordinates of the three positioning points. An optical assembly coordinate system is established with the mirror vertex as the origin and the optical axis direction as the coordinate system. The coordinates of the positioning points are mapped into the optical assembly coordinate system to obtain the spatial relationship between the positioning points and the optical axis, thus establishing a motion model of the positioning points following the optical element in the optical adjustment coordinate system. Finally, the two constructed motion models are connected by coordinate mapping using the positioning points to obtain the motion model of the optical element in the coordinate system. By calculating the changes in the positioning points using the six-dimensional adjustment required by the optical components, and then mapping the new positioning point coordinates to the coordinate system, the required adjustment amount for the mechanical assembly platform can be calculated through the positioning point transformation. This completes the conversion from optical adjustment to mechanical adjustment, and also corrects for optical component mounting errors during the conversion process. By repeatedly measuring the three positioning points set on the optical component fixture during the assembly process, the current optical axis direction and spatial pose of the mirror can be obtained, guiding the adjustment direction and amount during the assembly process, improving assembly accuracy, reducing assembly difficulty, and promoting unmanned assembly. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of an off-axis three-reflector system; Figure 2 A schematic diagram of the detection optical path constructed according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the measurement data of the optical element and its tooling according to an embodiment of the present invention; Figure 4A This is a schematic diagram of the Zernike fitting mirror surface shape data in an embodiment of the present invention; Figure 4BThis is a schematic diagram of the Zernike fitted mirror surface shape data after correcting piston and titlt in an embodiment of the present invention; Figure 5 This is a schematic diagram of an optical adjustment coordinate system with the mirror vertex as the origin and the optical axis as the coordinate axis in an embodiment of the present invention; Figure 6 A schematic diagram of establishing a concentric spherical model of the same layer based on the three rotation data measured in the coordinate system in this embodiment of the invention; Figure 7 This is a schematic diagram showing the coordinates of the center of motion and the direction of motion of the mechanical assembly table in the coordinate system in an embodiment of the present invention; Figure 8 This is a flowchart of an optical reference and mechanical reference transfer method provided according to an embodiment of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] The following is combined with Figures 1-8 This paper describes a method for transferring optical and mechanical references according to embodiments of the present invention. The method for transferring optical and mechanical references in this invention is described in detail. It is important to understand that the following description is merely illustrative and not intended to limit the scope of the invention.

[0020] The optical reference and mechanical reference transfer method according to embodiments of the present invention includes: Step 10: Set three positioning points for the optical element and unify these three positioning points with the mirror surface shape data in the same coordinate system. Specifically, the optical element can be mounted on a fixture, and three ball bearings can be set on the flat fixture as positioning points according to the fixture structure. Measure the mirror surface shape data and the coordinate space of the positioning points. Figure 1 This is a schematic diagram of an off-axis three-reflector system.

[0021] The optical components are mounted on the mechanical assembly table, and the overall assembly structure is fixed to the camera lens frame. Figure 2 To construct the detection optical path diagram, the following components are included: laser tracker 1, laser tracker adjustment frame 2, camera lens frame 3, upper orientation point 4, lower orientation point 5, camera optical element 6, optical element fixture 7, mechanical assembly adjustment table 8, mechanical assembly adjustment table fixture 9, optical platform 10, laser tracker 11, and laser tracker adjustment frame 12.

[0022] Step 20: Obtain the spatial orientation of the optical element, move the mechanical assembly table a predetermined distance along its own assembly x-direction, and measure the spatial coordinates of the three positioning points after the movement. Combination Figure 2 As shown, keeping the mechanical assembly table 8 stationary, the spatial coordinates of the measurement positioning points in the coordinate system of the laser tracker 11 are used as the in-situ coordinates. Based on the adjustment data of the mechanical assembly table 8, the mechanical assembly table 8 is moved a predetermined distance (e.g., 1 mm) along its X, Y, and Z axes respectively to obtain the spatial data of the three positioning points after the movement. The mechanical assembly table is then rotated by a fixed angle around the X, Y, and Z axes to obtain the spatial coordinate data of the three positioning points around the mechanical assembly motion center. Two directional ball mounts are set vertically on the camera frame, and the collected data are used as the directional points for establishing the coordinate system.

[0023] Step 30: Process the spatial orientation of the optical element and the spatial coordinate data of the three positioning points after the movement to obtain the spatial relationship between the mirror vertex and the positioning point, and establish an optical adjustment coordinate system with the mirror vertex as the origin and the optical axis as the coordinate system, and calculate the spatial coordinates of the positioning point in the coordinate system. Step 40: Repeat step 20 multiple times in the six-dimensional direction to obtain the displacement coordinate change data of the mechanical assembly table in the coordinate system; Based on the rotation data in three directions, a three-layer concentric spherical model from the positioning point to the motion center of the mechanical assembly table is established. The spatial coordinates of the motion center of the mechanical assembly table in the coordinate system of the laser tracker are obtained. Based on the three translation data, the spatial coordinate changes of the motion center along the three coordinate axes are obtained, and the motion direction of the mechanical assembly table in the coordinate system is obtained. Establish a motion model of the mechanical assembly in the coordinate system, calculate the rotation matrix and translation vector of the tooling by the coordinate changes of the three positioning points, and inversely calculate the change parameters of the mechanical assembly platform. Step 50: By mapping the coordinates of the three positioning points in the optical adjustment coordinate system and the mechanical adjustment coordinate system, establish the motion relationship between the vertex of the optical element mirror and the motion center of the mechanical assembly table; convert the six-dimensional optical adjustment quantity into the coordinate transformation of the three positioning points through quaternion transformation, map the transformed three coordinates to the coordinate system of the laser tracker, calculate the new rotation matrix and translation vector, and then obtain the adjustment parameters of the mechanical assembly table, thus completing the conversion of the mechanical adjustment quantity.

[0024] According to the optical and mechanical reference transfer method of this invention, three positioning points are set on the optical element, and the three positioning points and mirror surface shape data are unified in the same coordinate system to obtain the spatial position and orientation of the optical element. The mechanical assembly table is moved a predetermined distance along its own assembly x-direction, and the spatial coordinates of the three positioning points after movement are measured again. After data processing, the motion center of the mechanical adjustment frame and the spatial coordinates and motion direction of each coordinate axis in the coordinate system are calculated to establish a motion model of the optical element tooling following the mechanical adjustment frame in the coordinate system. The six-dimensional adjustment amount of the mechanical adjustment frame is calculated by the change of the spatial coordinates of the three positioning points. An optical assembly coordinate system is established with the mirror vertex as the origin and the optical axis direction as the coordinate system. The coordinates of the positioning points are mapped to the optical assembly coordinate system to obtain the spatial relationship between the positioning points and the optical axis, and a motion model of the positioning points following the optical element in the optical adjustment coordinate system is established. Finally, the two constructed motion models are connected by coordinate mapping using the positioning points to obtain the motion model of the optical element in the coordinate system. By calculating the changes in the positioning points using the six-dimensional adjustment required by the optical components, and then mapping the new positioning point coordinates to the coordinate system, the required adjustment amount for the mechanical assembly platform can be calculated through the positioning point transformation. This completes the conversion from optical adjustment to mechanical adjustment, and also corrects for optical component mounting errors during the conversion process. By repeatedly measuring the three positioning points set on the optical component fixture during the assembly process, the current optical axis direction and spatial pose of the mirror can be obtained, guiding the adjustment direction and amount during the assembly process, improving assembly accuracy, reducing assembly difficulty, and promoting unmanned assembly.

[0025] According to some embodiments of the present invention, in step 30, the processing of the spatial orientation of the optical element and the spatial coordinate data of the three positioning points after movement includes: The spatial coordinate data of the three positioning points obtained in step 20 after the movement are processed to establish the spatial relationship between the mirror surface shape data and the mirror surface shape data in step 10, and to obtain the direction of the mirror optical axis.

[0026] Furthermore, in step 30, the processing of the spatial coordinate data of the three moving positioning points obtained in step 20 specifically includes: using the Zernike fitting method to analyze the piston and tilt data of the mirror surface shape, so as to establish the spatial relationship between the mirror surface shape data and the mirror surface shape data in step 10, and obtain the direction of the mirror optical axis.

[0027] According to some embodiments of the present invention, in step 20, the optical element fixture is installed on the mechanical assembly table, and the overall assembly structure is fixed on the camera lens frame. The mechanical assembly table is kept stationary, and the spatial coordinates of the measurement positioning point in the laser tracker measurement coordinate system are used as the original position. According to the adjustment data of the mechanical assembly table, the mechanical assembly table is controlled to move a fixed distance in the X-axis, Y-axis and Z-axis directions respectively to obtain the spatial data of the three positioning points after the movement.

[0028] According to some embodiments of the present invention, in step 40, the mechanical assembly table is rotated by fixed angles around the X, Y, and Z axes to obtain the spatial coordinate data of the three positioning points rotating around the mechanical assembly motion center.

[0029] According to some embodiments of the present invention, two directional point ball seats are set vertically on the camera frame, and the collected data are used as directional points for establishing a coordinate system.

[0030] According to some embodiments of the present invention, in step 40, since the positioning points on the optical element tooling are fixed and the distance between them and the motion center of the mechanical assembly platform remains unchanged, the trajectory left by the mechanical assembly platform driving the three positioning points to rotate around the motion center can be fitted into a three-layer concentric sphere model, and the sphere center coordinates can be obtained by using the spatial coordinate data of the positioning points to perform spherical fitting.

[0031] According to some embodiments of the present invention, in step 40, step 20 is repeated six times in a six-dimensional direction.

[0032] According to some embodiments of the present invention, in step 50, calculating the tooling rotation matrix and translation vector through the coordinate changes of the three positioning points specifically includes: The rotation matrix and translation vector of the mechanical adjustment model around the motion center are calculated by changing the coordinates of the three positioning points. The adjustment amount of the mechanical assembly platform is then calculated by Euler angle transformation.

[0033] According to some embodiments of the present invention, in step 50, The six-dimensional optical adjustment includes translational adjustment and rotational adjustment. Translational adjustment is converted into vector form, and rotational adjustment is converted into a rotation matrix using quaternions.

[0034] The following reference Figures 1-8 A detailed description of the optical and mechanical reference transfer method according to embodiments of the present invention includes: (1) Mount the camera optical element 6 onto the optical element fixture 7, and set three positioning points on the flat fixture according to the optical element fixture 7. Unify the positioning points and the mirror surface shape data in the same coordinate system.

[0035] (2) Install the camera optical element 6 and the optical element tooling 7 on the mechanical assembly platform 8, and fix the camera optical element 6 assembly structure on the camera lens frame 3.

[0036] (3) Record the current spatial pose of the optical component fixture 7, move the mechanical mounting table 8 1mm along its own mounting x direction, and measure the spatial coordinates of the three positioning points after the movement.

[0037] (4) Import the measurement data from step (1) into the simulation software, and use the Zernike fitting method to analyze the piston and tilt data of the mirror surface shape, establish the spatial relationship between the mirror surface shape data and the measurement results from step (1), and obtain the direction of the mirror optical axis. Based on the spatial data of the three positioning points, establish the spatial relationship between the mirror vertex and the positioning points, and establish an optical adjustment coordinate system with the mirror vertex as the origin and the optical axis as the coordinate system, and calculate the spatial coordinates of the positioning points in this coordinate system.

[0038] (5) Repeat step (3) 6 times in the six-dimensional direction to obtain the displacement coordinate change data of the mechanical assembly table 8 in the coordinate system. Based on the rotation data in the three directions, establish a three-layer concentric spherical model from the positioning point to the motion center of the mechanical assembly table, and obtain the spatial coordinates of the motion center of the mechanical assembly table 8 in the coordinate system of the laser tracker. Based on the three translation data, obtain the spatial coordinate changes of the motion center along the three coordinate axes, and obtain the motion direction of the mechanical assembly table 8 in the coordinate system. Establish the motion model of the mechanical assembly table in the coordinate system, calculate the tooling rotation matrix and translation vector through the coordinate changes of the three positioning points, and back-calculate the change parameters of the mechanical assembly table platform.

[0039] (6) By mapping the coordinates of the three positioning points in the optical adjustment coordinate system and the mechanical adjustment coordinate system, the motion relationship between the vertex of the optical element mirror and the motion center of the mechanical assembly table 8 is established. The six-dimensional optical adjustment quantity is converted into the coordinate transformation of the three positioning points through quaternion transformation. After mapping the transformed three coordinates to the coordinate system of the laser tracker 11, the new rotation matrix and translation vector are calculated, and the adjustment parameters of the mechanical assembly table 8 are obtained, thus completing the conversion of the mechanical adjustment quantity.

[0040] The following section uses an off-axis three-mirror system as an example to elaborate on the optical and mechanical reference transfer method in this invention: Step 1: Mount the camera optical element 6 onto the optical element fixture 7, and set three ball seats on the flat fixture as positioning points according to the optical element fixture 7. Measure the mirror surface shape data and the coordinate space of the positioning points. Figure 1 This is a schematic diagram of an off-axis three-reflector system.

[0041] Step 2: Install the optical component fixture 7 on the mechanical assembly table 8, and fix the overall assembly structure on the camera lens frame 3. Figure 2To construct the detection optical path diagram, the following components are included: laser tracker 1, laser tracker adjustment frame 2, camera lens frame 3, upper orientation point 4, lower orientation point 5, camera optical element 6, optical element fixture 7, mechanical assembly adjustment table 8, mechanical assembly adjustment table fixture 9, optical platform 10, laser tracker 11, and laser tracker adjustment frame 12.

[0042] Step 3: Keeping the mechanical assembly platform 8 stationary, the spatial coordinates of the positioning points in the coordinate system of the laser tracker 11 are used as the in-situ coordinates. Based on the adjustment data of the mechanical assembly platform 8, the platform is moved a fixed distance along its X, Y, and Z axes to obtain the spatial data of the three positioning points after movement. The platform 8 is then rotated by a fixed angle around the X, Y, and Z axes to obtain the spatial coordinate data of the three positioning points around the mechanical assembly motion center. Two directional ball mounts are set vertically on the camera frame 3 to collect data as the directional points for establishing the coordinate system.

[0043] Step four: Import the collected surface shape data and positioning point data into the analysis software. Figure 3 This is a schematic diagram of component-tooling measurement data, including coordinates of positioning points 1, 2, and 3, and optical component surface shape data 4. The collected surface shape data is fitted to the designed surface shape, and the pistion and titlt data are calculated, such as... Figure 4A A schematic diagram of the mirror surface shape data fitted to Zernike. The corrected mirror surface shape is as follows. Figure 4B As shown, the spatial coordinates of the mirror vertex and the direction of the optical axis in the coordinate system of the coordinate measuring machine are obtained. Through positioning point mapping, the relationship between the measurement coordinate system and the component-tooling measurement coordinate system is established. The orientation point measured in step two is mapped to the coordinate system of the coordinate measuring machine, serving as the X-axis direction. Using the mirror vertex as the origin, the optical axis and X-axis directions are orthogonalized to establish an optical adjustment coordinate system. The positioning point coordinates are then mapped to the optical adjustment coordinate system to obtain the optical adjustment model. Figure 5 This is a schematic diagram of an optical adjustment coordinate system with the vertex of the mirror as the origin and the optical axis as the coordinate axis. It includes positioning point 1, positioning point 2, positioning point 3, surface data 4, upper orientation point 5, lower orientation point 6, mirror vertex 7, optical axis orientation point 8, vertical vector of the mirror frame 9, optical adjustment coordinate system X-axis 10, optical adjustment coordinate system Z-axis 11, and optical adjustment coordinate system Y-axis 12.

[0044] Step 5: Because the positioning points on the optical component fixture 7 are fixed, and their distance from the motion center of the mechanical assembly platform 8 remains constant, the trajectory left by the mechanical assembly platform 8 rotating around the motion center with the three positioning points can be fitted into a three-layer concentric sphere model. The coordinates of the sphere center, which are also the coordinates of the motion center, are obtained by using the spatial coordinate data of the positioning points for spherical fitting. Figure 6A schematic diagram of a concentric spherical model is established for the three rotation data, including rotation trajectories of the positioning point 1, 2, and 3, three concentric spheres 4, and the center of the sphere 5. By calculating the coordinates of the center of the sphere after three translations based on the relationship between the center of motion and the sphere, the position and direction of the center of motion of the mechanical assembly table in the coordinate system can be obtained. Through coordinate mapping, the coordinates of the positioning points in the coordinate system of the mechanical assembly table itself are obtained, and the mechanical adjustment model is established. Figure 7 This diagram illustrates the coordinates and direction of motion of the mechanical assembly platform in a coordinate system, including positioning points 1, 2, and 3; the center point of motion of the mechanical assembly platform 4; the center position of the mechanical assembly platform after movement along the X-axis 5; the center position of the mechanical assembly platform after movement along the Y-axis 6; the center position of the mechanical assembly platform after movement along the Z-axis 7; the X-axis direction of the mechanical assembly platform 8; the Y-axis direction of the mechanical assembly platform 9; and the Z-axis direction of the mechanical assembly platform 10. By changing the coordinates of the three positioning points, the rotation matrix and translation vector of the mechanical adjustment model around the center of motion can be calculated. Through Euler angle transformation, the adjustment amount of the mechanical assembly platform can be calculated inversely.

[0045] Step Six, Figure 8 This invention provides a flowchart of a method for transferring optical and mechanical references. The method involves mapping the coordinates of three positioning points in the optical adjustment coordinate system to those in the mechanical adjustment coordinate system, establishing the motion relationship between the vertex of the optical element's mirror and the motion center of the mechanical assembly table. The adjustment amount of the optical element is divided into two parts: the translation adjustment amount is converted into a vector form, and the rotation adjustment amount is converted into a rotation matrix using quaternions. The adjusted positioning point coordinates in the optical adjustment coordinate system are calculated and mapped to the mechanical adjustment coordinate system. The rotation matrix and translation vector of the mechanical assembly model before and after adjustment in the mechanical adjustment coordinate system are calculated and converted into input parameters for the mechanical assembly table, completing the conversion between optical and mechanical adjustment amounts.

[0046] According to the optical reference and mechanical reference transfer method of the present invention, a target ball seat is set as a positioning point on the lens fixture of the camera optical element. The spatial coordinates of the target ball are measured, and the coordinate changes of the optical element fixture following the mechanical adjustment frame are recorded in the global coordinate system. By methods such as spherical fitting and coordinate mapping, the motion center of the mechanical adjustment frame and the spatial coordinates and motion directions of each coordinate axis in the coordinate system are calculated. A motion model of the optical element fixture following the mechanical adjustment frame in the coordinate system is established. The six-dimensional adjustment amount of the mechanical adjustment frame is calculated by back-calculating the spatial coordinate changes of the three positioning points.

[0047] Before measurement, the pose relationship between the mirror and the fixture needs to be obtained. The tilt error of the plane formed by the surface shape relative to the positioning point is calculated using the Zernike fitting method to obtain the optical axis direction of the mirror. With the vertex of the mirror as the origin and the optical axis direction as the coordinate system, an optical adjustment coordinate system is established, and the coordinates of the positioning point are mapped to the optical adjustment coordinate system to obtain the spatial relationship between the positioning point and the optical axis. A motion model of the positioning point following the optical element in the optical adjustment coordinate system is then established.

[0048] Finally, coordinate mapping is performed using the positioning points to connect the two constructed motion models, resulting in the motion model of the optical element in the coordinate system. The changes in the positioning points can be calculated using the six-dimensional adjustment required by the optical element. The new positioning point coordinates are then mapped back to the coordinate system to obtain the new positioning point coordinates. Finally, the required adjustment of the mechanical assembly platform is calculated through positioning point transformation, completing the conversion from optical adjustment to mechanical adjustment. During this conversion process, corrections for optical element mounting errors are also performed.

[0049] By repeatedly measuring the three positioning points set on the optical component fixture during the assembly and adjustment process, the optical axis direction and spatial pose of the mirror can be obtained. This guides the adjustment direction and amount during the assembly and adjustment process, improves the accuracy of assembly and adjustment, reduces the difficulty of assembly and adjustment, and promotes the realization of unmanned assembly and adjustment.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for transferring optical and mechanical references, characterized in that, include: Step 10: Set three positioning points for the optical element and unify the three positioning points with the mirror surface shape data in the same coordinate system; Step 20: Obtain the spatial orientation of the optical element, move the mechanical assembly table a predetermined distance along its own assembly x-direction, and measure the spatial coordinates of the three positioning points after the movement. Step 30: Process the spatial orientation of the optical element and the spatial coordinate data of the three positioning points after the movement to obtain the spatial relationship between the mirror vertex and the positioning point, and establish an optical adjustment coordinate system with the mirror vertex as the origin and the optical axis as the coordinate system, and calculate the spatial coordinates of the positioning point in the coordinate system. Step 40: Repeat step 20 multiple times in the six-dimensional direction to obtain the displacement coordinate change data of the mechanical assembly table in the coordinate system; Based on the rotation data in three directions, a three-layer concentric spherical model from the positioning point to the motion center of the mechanical assembly table is established. The spatial coordinates of the motion center of the mechanical assembly table in the coordinate system of the laser tracker are obtained. Based on the three translation data, the spatial coordinate changes of the motion center along the three coordinate axes are obtained, and the motion direction of the mechanical assembly table in the coordinate system is obtained. Establish a motion model of the mechanical assembly in the coordinate system, calculate the rotation matrix and translation vector of the tooling by the coordinate changes of the three positioning points, and inversely calculate the change parameters of the mechanical assembly platform. Step 50: By mapping the coordinates of the three positioning points in the optical adjustment coordinate system and the mechanical adjustment coordinate system, establish the motion relationship between the vertex of the optical element mirror and the motion center of the mechanical assembly table; convert the six-dimensional optical adjustment quantity into the coordinate transformation of the three positioning points through quaternion transformation, map the transformed three coordinates to the coordinate system of the laser tracker, calculate the new rotation matrix and translation vector, and then obtain the adjustment parameters of the mechanical assembly table, thus completing the conversion of the mechanical adjustment quantity.

2. The method for transferring optical and mechanical references according to claim 1, characterized in that, In step 30, the processing of the spatial orientation of the optical element and the spatial coordinate data of the three positioning points after the movement includes: The spatial coordinate data of the three positioning points obtained in step 20 after the movement are processed to establish the spatial relationship between the mirror surface shape data and the mirror surface shape data in step 10, and to obtain the direction of the mirror optical axis.

3. The method for transferring optical and mechanical references according to claim 2, characterized in that, In step 30, the processing of the spatial coordinate data of the three moving positioning points obtained in step 20 specifically includes: using the Zernike fitting method to analyze the piston and tilt data of the mirror surface shape, so as to establish the spatial relationship between the mirror surface shape data and the mirror surface shape data in step 10, and obtain the direction of the mirror optical axis.

4. The method for transferring optical and mechanical references according to claim 1, characterized in that, In step 20, the optical component fixture is installed on the mechanical assembly table, and the overall assembly structure is fixed on the camera lens frame. The mechanical assembly table is kept stationary, and the spatial coordinates of the measurement positioning point in the laser tracker measurement coordinate system are used as the original position. According to the adjustment data of the mechanical assembly table, the mechanical assembly table is controlled to move a fixed distance in the X-axis, Y-axis and Z-axis directions respectively to obtain the spatial data of the three positioning points after the movement.

5. The method for transferring optical and mechanical references according to claim 4, characterized in that, In step 40, the mechanical assembly table is rotated by fixed angles around the X, Y, and Z axes to obtain the spatial coordinate data of the three positioning points rotating around the mechanical assembly motion center.

6. The method for transferring optical and mechanical references according to claim 5, characterized in that, Two directional ball mounts are set vertically on the camera frame, and the collected data are used as directional points to build a coordinate system.

7. The method for transferring optical and mechanical references according to claim 4, characterized in that, In step 40, since the positioning points on the optical component tooling are fixed and the distance between them and the motion center of the mechanical assembly platform remains unchanged, the trajectory left by the mechanical assembly platform driving the three positioning points to rotate around the motion center can be fitted into a three-layer concentric sphere model. The coordinates of the sphere center are obtained by using the spatial coordinate data of the positioning points to perform spherical fitting.

8. The method for transferring optical and mechanical references according to claim 1, characterized in that, In step 40, step 20 is repeated six times in a six-dimensional direction.

9. The method for transferring optical and mechanical references according to claim 1, characterized in that, In step 50, the calculation of the tooling rotation matrix and translation vector through the coordinate changes of the three positioning points specifically includes: The rotation matrix and translation vector of the mechanical adjustment model around the motion center are calculated by changing the coordinates of the three positioning points. The adjustment amount of the mechanical assembly platform is then calculated by Euler angle transformation.

10. The method for transferring optical and mechanical references according to claim 1, characterized in that, In step 50, The six-dimensional optical adjustment includes translational adjustment and rotational adjustment. Translational adjustment is converted into vector form, and rotational adjustment is converted into a rotation matrix using quaternions.

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