Automatic assembling and adjusting method for coaxial reflective optical system

Abstract

The invention relates to the technical field of precise optical machine assembly and adjustment, in particular to an automatic assembly and adjustment method for a coaxial reflection type optical system, which comprises the following steps of: pre-assembling a primary mirror assembly and a secondary mirror assembly, and carrying out coaxial centering calibration on the primary mirror and the secondary mirror; the universal adjusting frame is used for installing the calibrated overall structure of the optical system on the gantry bracket; removing the secondary mirror assembly, detecting the pose of the primary mirror assembly by matching the laser interferometer with the standard spherical reflector assembly, and enabling the optical axis of the primary mirror to coincide with the optical axis of the laser interferometer through adjustment of the universal adjusting frame; the secondary mirror assembly is reassembled, and the secondary mirror five-dimensional adjusting tool assembly is in butt joint with the secondary mirror assembly; controlling the secondary mirror five-dimensional adjusting tool assembly to adjust the secondary mirror assembly through the laser interferometer by adopting a fuzzy control algorithm; the primary mirror assembly and the secondary mirror assembly are fixed through the primary and secondary mirror connecting bracket assembly; according to the invention, the adjustment efficiency and the assembly precision of the optical system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of precision optical and mechanical assembly and adjustment, and in particular to an automated assembly and adjustment method for a coaxial reflective optical system. Background Art

[0002] The assembly process is a key link in the manufacturing process of complex and precise optical systems, connecting design and performance. Its technical level directly affects the imaging quality and reliability of the optical system. Currently, most of the assembly and adjustment methods used in the industry are manual, and the operator needs to repeatedly adjust the position of the optical system lenses based on the test results. This type of assembly and adjustment method has significant limitations: first, the repeated disassembly and adjustment of the primary and secondary mirrors in the optical system is time-consuming and difficult to ensure repeatability; second, the adjustment of the lens position during the optical system adjustment process is heavily dependent on the operator's operating skills, which is prone to human errors. Especially in optical systems with extremely high precision requirements, micron-level assembly errors can cause significant wavefront distortion, and traditional assembly and adjustment methods are difficult to meet the needs of mass production.

[0003] With the development of automation technology, the introduction of precision motion control hardware and software systems in conjunction with detection technology has become an inevitable trend to improve the accuracy and efficiency of assembly and adjustment. Therefore, an automated assembly and adjustment method that integrates high-precision sensor feedback and multi-axis coordinated motion control is urgently needed to break the bottleneck of manual operation and achieve a synergistic improvement in the accuracy and efficiency of coaxial optical system assembly and adjustment. Summary of the Invention

[0004] In view of the above problems, the present invention provides an automated assembly and adjustment method for a coaxial reflective optical system, which solves the technical problems of low assembly and adjustment efficiency and limited assembly precision of reflective optical systems in the prior art.

[0005] On the one hand, the present invention provides an automated assembly and adjustment device for a coaxial reflective optical system, characterized in that the coaxial reflective optical system includes a primary mirror assembly 1, a secondary mirror assembly 2, a primary-secondary mirror connecting bracket assembly 3, and a standard spherical reflector assembly 4, wherein the primary mirror assembly 1 and the secondary mirror assembly 2 are detachably connected via the primary-secondary mirror connecting bracket assembly 3, and the standard spherical reflector assembly 4 is coaxially connected to the primary mirror assembly 1;

[0006] The automated assembly and adjustment device for the coaxial reflective optical system includes a gantry bracket 5, a universal adjustment frame 6, and a secondary mirror five-dimensional adjustment tooling assembly 7; the universal adjustment frame 6 is installed on the gantry bracket 5, and the universal adjustment frame 6 can be used to install the coaxial reflective optical system. A secondary mirror five-dimensional adjustment tooling assembly 7 is provided on one side of the gantry bracket 5.

[0007] Preferably, the primary mirror assembly 1 comprises a primary mirror 101 and a primary mirror mounting base 102, and the primary mirror 101 is fixed to the primary mirror mounting base 102 by connecting bolts;

[0008] The primary and secondary mirror connecting bracket assembly 3 includes a primary mirror base bracket 301 and a secondary mirror connecting bracket 302. The primary mirror base bracket 301 is connected to the primary mirror mounting base 102. The secondary mirror connecting bracket 302 is detachably connected to the primary mirror base bracket 301 via a positioning pin and a locking bolt.

[0009] The secondary mirror assembly 2 includes a secondary mirror 201, a secondary mirror connecting gasket 202, and a secondary mirror adjustment gasket 203; the secondary mirror connecting gasket 202 and the end face of the secondary mirror connecting bracket 302 are connected by bolts; the secondary mirror connecting gasket 202, the end face of the secondary mirror connecting bracket 302, the secondary mirror adjustment gasket 203 and the secondary mirror 201 are connected in sequence.

[0010] Preferably, the standard spherical mirror assembly 4 includes a standard spherical reflector 401 and a spherical mirror connecting fixture 402, and the standard spherical reflector 401 is coaxially mounted with the main mirror assembly 1 through the connecting fixture 402 having an optical axis calibration function;

[0011] The secondary mirror five-dimensional adjustment fixture assembly 7 includes a two-axis alignment platform 701, an electric rotating platform 702, an electric lifting platform 703, an electric swing platform 704, a secondary mirror adjustment connection fixture 705 and a contact displacement sensor 706 connected in sequence.

[0012] In one aspect, the present invention provides an alignment method according to the coaxial reflective optical system automated alignment device, comprising the following steps:

[0013] Step S1, pre-assembling the primary mirror assembly 1 and the secondary mirror assembly 2 through the primary-secondary mirror connecting bracket assembly 3 to form an optical system, and performing coaxial centering calibration of the primary and secondary mirrors on the optical system using a dual-optical path centring instrument;

[0014] Step S2, mounting the calibrated optical system structure onto the universal adjustment bracket 6 on the gantry bracket 5;

[0015] Step S3, dismantling the secondary mirror assembly 2, using a laser interferometer in conjunction with a standard spherical reflector assembly 4 to detect the posture of the primary mirror 101 in the primary mirror assembly 1, and adjusting the posture of the primary mirror 101 through the universal adjustment mount 6 so that the optical axis of the primary mirror 101 coincides with the optical axis of the laser interferometer;

[0016] Step S4: reassembling the secondary mirror assembly 2, and docking the secondary mirror five-dimensional adjustment fixture assembly 7 with the secondary mirror assembly 2;

[0017] Step S5: Using the posture of the primary mirror assembly 1 as a reference, the secondary mirror assembly 2 is adjusted by controlling the secondary mirror five-dimensional adjustment fixture assembly 7 through a laser interferometer and a fuzzy control algorithm to compensate for the Zernike polynomial coefficients of the wavefront aberration measured by the laser interferometer;

[0018] Step S6: Fix the primary mirror assembly 1 and the secondary mirror assembly 2 through the primary-secondary mirror connecting bracket assembly 3 to complete the assembly and adjustment of the entire optical system.

[0019] Preferably, step S1 specifically includes:

[0020] Step S1-1, detachably connecting the primary mirror base bracket 301 and the secondary mirror connecting bracket 302 through a positioning pin and a locking bolt;

[0021] Step S1-2: Use a dual-optical path centering instrument to calibrate the primary mirror 101 and the secondary mirror 201 to ensure that the optical axis coaxiality error between the primary mirror 101 and the secondary mirror 201 does not exceed 0.05 mm.

[0022] Preferably, step S3 specifically includes:

[0023] Step S3-1, detaching the secondary mirror connecting bracket 302 from the primary mirror base bracket 301, so that the secondary mirror assembly 2 is detached, and the remaining primary mirror base bracket 301, primary mirror assembly 1 and standard spherical mirror assembly 4 are kept in the installation position of the universal adjustment frame 6;

[0024] Step S3-2, coaxially mounting the standard spherical reflector 401 in the standard spherical reflector assembly 4 with the primary mirror assembly 1 through the connecting fixture 402 with an optical axis calibration function;

[0025] Step S3-3, with the center of the primary mirror 101 as the origin O of the coordinate system, the direction of the light emitted from the interferometer as the positive direction of the Z axis, and the horizontal direction perpendicular to the Z axis as the X axis to establish a primary mirror coordinate system, so that the spherical mirror connecting fixture 402 moves along the Z axis, and the focus of the standard spherical reflector 401 is adjusted to a position conjugate with the focus of the primary mirror 101. The posture of the primary mirror 101 is adjusted by the universal adjustment frame 6 so that the 7th and 8th coefficients of the Zernike polynomial wave aberration coefficient of the primary mirror in the detection result of the laser interferometer are both below 0.05.

[0026] Preferably, step S4 specifically includes:

[0027] Step S4-1, the secondary mirror connecting bracket 302 is matched with the positioning hole of the primary mirror base bracket 301 using a positioning pin and a torque-controlled fastening bolt to reassemble the secondary mirror assembly 2;

[0028] Step S4-2: Three contact displacement sensors 706 monitor in real time the distance between the contact end faces of the secondary mirror adjustment and connection fixture 705 and the secondary mirror connection gasket 202; when the three distances are equal, the secondary mirror adjustment and connection fixture 705 is rigidly connected to the secondary mirror connection gasket 202 by tightening bolts;

[0029] Step S4-3: Release the coordination between the primary mirror base bracket 301 and the secondary mirror connecting bracket 302, so that the secondary mirror five-dimensional adjustment fixture assembly 7 can freely adjust the posture of the secondary mirror assembly 2.

[0030] Preferably, step S5 specifically includes:

[0031] Step S5-1, establishing a matrix model of the five-dimensional adjustment fixture assembly 7 including five-degree-of-freedom motion parameters based on the primary mirror coordinate system;

[0032] Step S5-2, using a fuzzy control algorithm and a gradient descent algorithm, the compensation amount is calculated based on the wavefront aberration data measured by the laser interferometer and the movement of the five-dimensional adjustment tooling assembly 7 is controlled so that the coefficients of the 7th and 8th items of the Zernike polynomial wavefront aberration coefficients in the detection results are both less than 0.05;

[0033] Step S5-3: Repairing and grinding the connection gasket in the secondary mirror adjustment assembly according to the motion parameters of the five-dimensional adjustment tooling assembly 7.

[0034] Preferably, in step S5-1, the motion parameters Δx, Δz, θ of each part of the five-dimensional adjustment tooling assembly 7 are adjusted. y ,Δy,θ x Determine the matrix model R x ,T y ,R y ,T xz ;

[0035] Wherein, Δx and Δz represent the X-axis and Z-axis translation of the two-axis alignment platform 701, θ y represents the rotation amount of the electric rotating platform 702 around the Y axis, Δy represents the translation amount of the electric lifting platform 703 along the Y axis, and θ x Indicates the swing amount of the electric swing table 704 around the X axis, R x ,T y ,R y ,T xz They are the motion matrices of the two-axis alignment platform 701, the electric rotating platform 702, the electric lifting platform 703, and the electric swing platform 704.

[0036] Preferably, step S5-2 specifically includes:

[0037] Step S5-2-1, using a fuzzy control algorithm, calculate the target position of the secondary mirror 201 according to the values of the 7th and 8th coefficients of the Zernike polynomial wave aberration coefficients in the detection results;

[0038] Step S5-2-2: Determine the target transformation matrix T according to the target pose t arg et , define the error function:

[0039] E=||Rx ·T y ·R y ·T xz -T target || F

[0040] Where E represents the error function, ||·|| F is the Frobenius norm;

[0041] Use the gradient descent algorithm to minimize E and solve the motion parameters Δx, Δz, θ y ,Δy,θ x The motion parameters obtained are used to adjust the motion of the five-dimensional adjustment tooling component 7.

[0042] Compared with the prior art, the present invention has at least the following beneficial effects:

[0043] (1) This invention achieves high-precision optical axis alignment control by introducing a method for fine-tuning the primary and secondary mirror positions using a dual-optical path centering instrument combined with a standard spherical reflector. High-precision calibration of the primary mirror using a laser interferometer ensures precise alignment of the primary mirror's optical axis with the interferometer's optical axis, reducing human error and improving the coaxial accuracy of the primary and secondary mirrors in the overall optical system from a system structural perspective.

[0044] (2) This invention uses a fuzzy control algorithm to compensate for the wavefront aberration Zernike polynomial coefficients to control the secondary mirror's five-dimensional adjustment fixture assembly, automatically fine-tuning the secondary mirror's position and attitude. An error function optimization strategy is constructed, and a gradient descent algorithm is used to determine the optimal adjustment motion parameters, thereby improving the accuracy of the adjustment and enhancing the automation level of the adjustment process.

[0045] (3) The present invention provides a repeatable positioning support structure and a five-dimensional adjustment fixture, and uses a displacement sensor to achieve real-time monitoring and feedback. Once the automatic adjustment is completed, the adjustment result can be solidified through a precise connection structure, ensuring the stability of the system structure. This improves the efficiency of assembly and adjustment, and also significantly improves the consistency and efficiency of assembly and adjustment of different batches of optical systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings are only for purposes of illustrating particular embodiments and are not to be considered limiting of the invention.

[0047] Figure 1 This is a flow chart of the automated assembly and adjustment method for a coaxial reflective optical system provided by the present invention.

[0048] Figure 2 Schematic diagram of the automated assembly and adjustment tooling for the coaxial reflective optical system provided by the present invention.

[0049] Figure 3This is a schematic diagram of the coaxial reflective optical system assembly structure provided by the present invention.

[0050] Figure 4 Schematic diagram of imaging detection of the primary mirror assembly of the coaxial reflective optical system provided by the present invention.

[0051] Figure 5 Schematic diagram of the coaxial reflective optical system imaging detection provided by the present invention.

[0052] Figure 6 This is a schematic diagram of the automated assembly and adjustment control algorithm for the coaxial reflective optical system provided by the present invention.

[0053] Figure markings: 1-primary mirror assembly, 101-primary mirror, 102-primary mirror base, 2-secondary mirror assembly, 201-secondary mirror, 202-secondary mirror connecting gasket, 203-secondary mirror adjustment gasket, 3-primary and secondary mirror connecting bracket assembly, 301-primary mirror base bracket, 302-secondary mirror connecting bracket, 4-standard spherical reflector assembly, 401-standard spherical reflector, 402-spherical mirror connecting tooling, 5-gantry bracket, 6-universal adjustment bracket, 7-secondary mirror five-dimensional adjustment tooling assembly, 701-two-axis alignment platform, 702-electric rotary table, 703-electric lifting platform, 704-electric swing table, 705-secondary mirror adjustment connecting tooling, 706-contact displacement sensor. DETAILED DESCRIPTION

[0054] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0055] The present invention provides an assembly and adjustment tool for a coaxial reflective optical system and a supporting motion control algorithm. A detachable pre-assembled structure of a primary and secondary mirror assembly is constructed. A laser interferometer, combined with a standard spherical reflector and a connection tool with an optical axis calibration function, is used to perform multi-degree-of-freedom position adjustment on the primary mirror, aligning the primary mirror's optical axis with the interferometer's optical axis. This adjustment ensures the primary mirror's imaging quality. A five-dimensional adjustment tool assembly is used to precisely adjust the secondary mirror. During the adjustment process, a homogeneous matrix is used to model the five-dimensional motion process. The compensation amount is calculated using wavefront aberration data measured by laser interferometry. Numerical solution techniques such as fuzzy control algorithms and gradient descent methods are used to achieve efficient solutions and dynamic optimization, ultimately completing the automated assembly and adjustment of the optical system.

[0056] In order to illustrate the effectiveness of the method proposed in the present invention, the above technical solution of the present invention is described in detail below through a specific embodiment. A specific embodiment of the present invention discloses a coaxial reflective optical system automatic adjustment device, such as Figure 2 Figure 3 As shown, the coaxial reflective optical system includes a primary mirror assembly 1, a secondary mirror assembly 2, a primary-secondary mirror connecting bracket assembly 3 and a standard spherical reflector assembly 4, wherein the primary mirror assembly 1 and the secondary mirror assembly 2 are detachably connected via the primary-secondary mirror connecting bracket assembly 3, the standard spherical reflector assembly 4 is coaxially connected to the primary mirror assembly 1, and the coaxial reflective optical system automatic assembly and adjustment device includes a gantry bracket 5, a universal adjustment frame 6 and a secondary mirror five-dimensional adjustment tooling assembly 7.

[0057] The main mirror assembly 1 includes a main mirror 101 and a main mirror mounting base 102 , and the main mirror 101 is fixed to the main mirror mounting base 102 via connecting bolts.

[0058] The primary and secondary mirror connecting bracket assembly 3 includes a primary mirror base bracket 301 and a secondary mirror connecting bracket 302. The primary mirror base bracket 301 is connected to the primary mirror mounting base 102. The secondary mirror connecting bracket 302 is detachably connected to the primary mirror base bracket 301 through a positioning pin and a locking bolt. The flatness of the connecting end surfaces of the primary mirror base bracket 301 and the secondary mirror connecting bracket 302 is 0.02 mm.

[0059] The secondary mirror assembly 2 includes a secondary mirror 201, a secondary mirror connection gasket 202, and a secondary mirror adjustment gasket 203. The secondary mirror connection gasket 202 is connected to the end surface of the secondary mirror connection bracket 302 via bolts. The secondary mirror adjustment gasket 203 has three through holes. Bolts in the through holes secure the secondary mirror connection gasket 202, the end surface of the secondary mirror connection bracket 302, and the secondary mirror adjustment gasket 203 to the secondary mirror 201.

[0060] The standard spherical mirror assembly 4 includes a standard spherical reflector 401 and a spherical mirror connecting tool 402. The standard spherical reflector 401 is coaxially installed with the main mirror assembly 1 through the connecting tool 402 with optical axis calibration function. The connecting tool is provided with a positioning interface that matches the main mirror mounting base assembly.

[0061] The gimbal adjustment mount 6 is mounted on the gantry support 5. It can accommodate the entire optical system structure consisting of the primary mirror assembly 1, the secondary mirror assembly 2, and the primary-secondary mirror connecting bracket assembly 3. A secondary mirror five-dimensional adjustment fixture assembly 7 is installed on one side of the gantry support 5. This fixture assembly 7 comprises a two-axis alignment platform 701, an electric rotation stage 702, an electric lifting platform 703, an electric swing stage 704, a secondary mirror adjustment connecting fixture 705, and a contact displacement sensor 706, all connected in sequence.

[0062] Based on the above device, the present invention discloses a coaxial reflective optical system automatic assembly method, such as Figure 1 As shown, the following steps are included:

[0063] Step S1: pre-assemble the primary mirror assembly 1 and the secondary mirror assembly 2 through the primary-secondary mirror connecting bracket assembly 3 to form an overall optical system structure, and use a dual-optical path centering instrument to perform coaxial alignment of the primary and secondary mirrors on the overall optical system structure. Specific steps include the following.

[0064] Step S1-1, detachably connecting the primary mirror base bracket 301 and the secondary mirror connecting bracket 302 by means of positioning pins and locking bolts, so that the primary mirror assembly 1, the secondary mirror assembly 2 and the primary-secondary mirror connecting bracket assembly 3 form an integral structure;

[0065] Step S1-2: Use a dual-optical path centering instrument to calibrate the primary mirror 101 and the secondary mirror 201 to ensure that the optical axis coaxiality error between the primary mirror 101 and the secondary mirror 201 does not exceed 0.05 mm.

[0066] The present invention uses positioning pins and torque-controlled locking bolts to detachably connect the primary mirror base bracket 301 and the secondary mirror connecting bracket 302 to achieve accurate mechanical positioning, so that the secondary mirror assembly can return to the preset position after disassembly and reassembly, ensuring that the optical axes of the primary mirror and the secondary mirror remain within the error range of the optical axis calibration.

[0067] Step S2: Mounting the calibrated optical system structure onto the universal adjustment bracket 6 on the gantry bracket 5 .

[0068] like Figure 5 As shown, the primary mirror mounting base 102 of the optical system overall structure can be fixed to the universal adjustment frame 6 by bolts. In this step, the primary mirror mounting base 102 is mounted to the universal adjustment frame 6 on the gantry bracket 5, so that the optical system overall structure is mounted to the universal adjustment frame 6.

[0069] Step S3, remove the secondary mirror assembly 2, use a laser interferometer in conjunction with a standard spherical reflector assembly 4 to detect the position of the primary mirror 101 in the primary mirror assembly 1, and adjust the position of the primary mirror 101 through the universal adjustment frame 6 so that the optical axis of the primary mirror 101 coincides with the optical axis of the laser interferometer.

[0070] like Figure 4 As shown, in this step, a laser interferometer is used in conjunction with a standard spherical reflector assembly 4 to detect and adjust the posture of the primary mirror 101. The specific steps are as follows.

[0071] Step S3-1, detaching the secondary mirror connecting bracket 302 from the primary mirror base bracket 301, so that the secondary mirror assembly 2 is detached, and the remaining primary mirror base bracket 301, primary mirror assembly 1 and standard spherical mirror assembly 4 are kept in the installation position of the universal adjustment frame 6;

[0072] Step S3-2, coaxially mounting the standard spherical reflector 401 in the standard spherical reflector assembly 4 with the primary mirror assembly 1 through the connecting fixture 402 with an optical axis calibration function;

[0073] Step S3-3: With the optical axis of the primary mirror 101 as the Z axis, the center of the primary mirror surface as the coordinate system origin O, the direction of light emitted from the interferometer as the positive direction of the Z axis, and the direction perpendicular to the Z axis as the X axis, a reference coordinate system O-XYZ for subsequent secondary mirror fine adjustment is established according to a left-handed coordinate system. The spherical mirror connecting fixture 402 is adjusted to move axially along the Z axis, and the focus of the standard spherical reflector 401 is adjusted to a position conjugate with the focus of the primary mirror 101. The position of the primary mirror 101 is adjusted using the universal adjustment mount 6 so that the 7th and 8th coefficients of the Zernike polynomial wave aberration coefficients of the primary mirror based on the detection results of the laser interferometer are both below 0.05.

[0074] Step S4: reassemble the secondary mirror assembly 2 and dock the secondary mirror five-dimensional adjustment fixture assembly 7 with the secondary mirror assembly 2; the specific steps are as follows.

[0075] Step S4-1: Reconnect the secondary mirror connecting bracket 302 to the positioning hole of the primary mirror base bracket 301 using a positioning pin and a torque-controlled tightening bolt to reassemble the secondary mirror assembly 2. The bolt tightening torque requirement is 2.3N·m±10%, so that the secondary mirror and the primary mirror remain coaxial after the centering instrument calibration.

[0076] Step S4-2: adjust the relative position of the contact end faces of the secondary mirror adjustment connecting fixture 705 and the secondary mirror connecting gasket 202, and use three contact displacement sensors 706 evenly distributed around the circumference to monitor the three spacing values between the two contact end faces in real time. When the detection data of the three sensors reach an equal value state, it is determined that the fixture end face and the adjustment gasket end face of the secondary mirror adjustment assembly form a parallel spatial relationship, and finally complete the rigid connection between the secondary mirror adjustment connecting fixture 705 and the secondary mirror connecting gasket 202 by tightening the bolts.

[0077] Step S4-3, release the cooperation between the primary mirror base bracket 301 and the secondary mirror connecting bracket 302 again, so that the secondary mirror five-dimensional adjustment fixture assembly 7 can freely adjust the posture of the secondary mirror assembly 2.

[0078] Step S5: Based on the posture of the primary mirror assembly 1, the secondary mirror assembly 2 is adjusted by controlling the secondary mirror five-dimensional adjustment fixture assembly 7 through a laser interferometer and adopting a fuzzy control algorithm and a gradient descent algorithm to compensate for the Zernike polynomial coefficients of the wavefront aberration measured by the laser interferometer.

[0079] In this step, the system imaging quality is detected in real time by a laser interferometer, and the secondary mirror five-dimensional adjustment fixture assembly 7 is controlled to perform five degrees of freedom coordinated motion: X / Z translation, Y elevation, circumferential rotation, and pitch swing, to achieve fine adjustment of the position of the secondary mirror assembly 2 relative to the primary mirror 101. Specifically, the following steps are included:

[0080] Step S5-1: Establish a matrix model containing five-degree-of-freedom motion parameters using the primary mirror coordinate system O-XYZ as the reference coordinate system.

[0081] The position of the secondary mirror center relative to the primary mirror center is measured and calculated, and its coordinates are expressed as O2(x2, y2, z2), and a local coordinate system O2-X2Y2Z2 is established. The directions of the coordinate axes of this local coordinate system are consistent with those of the primary mirror coordinate system.

[0082] Based on the secondary mirror coordinate system O2-X2Y2Z2, a matrix model for the motion of each component of the secondary mirror five-dimensional adjustment assembly is established. The current parameters of each subassembly of the secondary mirror five-dimensional adjustment fixture assembly 7 are read through the motion controller. These position parameters serve as the initial parameters. The motion parameters of each subassembly are described below.

[0083] The five-dimensional adjustment fixture assembly 7 is composed of various components in series. The movement of each subassembly acts on the coordinate system in a specific order. In this embodiment, the movement of each subassembly includes: the translation of the X / Z two-axis positioning platform 701, the movement parameters are Δx, Δz, the rotation of the electric rotary table 702 around the Y axis, the movement parameter is θ y The electric lifting platform 703 moves along the Y axis, and the motion parameter is Δy. The electric swing platform 704 swings around the X axis, and the motion parameter is θ x The above parameters are used to construct the secondary motion matrix of each subcomponent.

[0084] The motion of each subassembly is represented by a homogeneous matrix. The motion matrix of the X / Z two-axis alignment platform 701 translation is:

[0085]

[0086] The motion matrix of the electric rotating stage 702 rotating around the Y axis is defined as:

[0087]

[0088] The motion matrix of the electric lift platform 703 moving along the Y axis is defined as:

[0089]

[0090] The motion matrix of the electric swing table 704 swinging around the X axis is defined as:

[0091]

[0092] Due to the series effect of the components, the overall transformation matrix of the entire adjustment process is expressed as follows:

[0093] T=R x ·T y ·R y ·T xz

[0094] The initial coordinate system of the secondary mirror is set to the unit matrix I. The final pose after the five-dimensional adjustment tooling is T final It can be expressed as:

[0095] T final =T·I

[0096] Step S5-2: Using a fuzzy control algorithm and a gradient descent algorithm, the compensation amount is calculated based on the wavefront aberration data measured by the laser interferometer and the motion of each axis is controlled so that the coefficients of the 7th and 8th terms of the Zernike polynomial coefficients of the optical system wavefront aberration are both less than 0.05.

[0097] The compensation of the wavefront aberration coefficient is mainly for the 7th and 8th items of the Zernike polynomial coefficients. The 7th item has a close relationship between the displacement along the X-axis and the rotation along the Y-axis, and the 8th item has a close relationship between the displacement along the Y-axis and the rotation along the X-axis. The target position of the secondary mirror 201 can be calculated according to the values of 7th and 8th items through the fuzzy control algorithm. t arg et -X t arg et Y t arg et Z t arg et represents the target pose of the secondary mirror.

[0098] The transformation matrix of the target pose of the secondary mirror relative to the local coordinate system O2-X2Y2Z2 is defined as T t arg et , expressed as:

[0099]

[0100] Among them, R t arg et represents a 3×3 rotation matrix, indicating the orientation of the target pose, t t arg et It is a 3×1 translation vector, which represents the distance between the target position and the initial position in each axis.

[0101] The target is to adjust the transformation matrix T of the five-dimensional adjustment frame t arg et Determined as the overall transformation matrix, we can get:

[0102] R x ·T y ·R y ·T xz =T t arg et

[0103] According to the above formula, it is necessary to solve the motion parameters of each part of the five-dimensional adjustment tooling: Δx, Δz, θ y ,Δy,θ x .

[0104] Wherein, Δx and Δz represent the X-axis and Z-axis translation of the two-axis alignment platform 701, θ y represents the rotation amount of the electric rotating platform 702 around the Y axis, Δy represents the translation amount of the electric lifting platform 703 along the Y axis, and θ x Indicates the swing amount of the electric swing table 704 around the X axis.

[0105] The motion parameters are calculated by numerical solution. First, the error function is defined:

[0106] E=||R x ·T y ·R y ·T xz -T target || F

[0107] Where E represents the error function, ||·|| F is the Frobenius norm, and the motion parameters are solved by minimizing E using a gradient descent algorithm. The motion of the five-dimensional adjustment tooling assembly 7 is adjusted based on the solved motion parameters.

[0108] Step S5-3: After obtaining the motion parameters, adjust the motion parameters Δx, Δz, θ according to the secondary mirror position. y ,Δy,θ x , trim and grind the connecting gasket in the secondary mirror adjustment assembly.

[0109] Step S6: Fix the primary mirror assembly 1 and the secondary mirror assembly 2 through the primary-secondary mirror connecting bracket assembly 3 to complete the assembly and adjustment of the entire optical system.

[0110] In the final step, the secondary mirror connecting bracket 302 is mounted to the primary mirror base bracket 301 to complete the assembly and adjustment of the entire optical system.

[0111] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0112] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0113] In the present invention, the terms "first", "second", "third", and "fourth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0114] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A coaxial reflective optical system automatic assembly and adjustment device, characterized in that: The coaxial reflective optical system comprises a primary mirror assembly (1), a secondary mirror assembly (2), a primary-secondary mirror connecting bracket assembly (3), and a standard spherical reflector assembly (4), wherein the primary mirror assembly (1) and the secondary mirror assembly (2) are detachably connected via the primary-secondary mirror connecting bracket assembly (3), and the standard spherical reflector assembly (4) is coaxially connected to the primary mirror assembly (1); The coaxial reflective optical system automated assembly and adjustment device comprises a gantry bracket (5), a universal adjustment frame (6), and a secondary mirror five-dimensional adjustment tooling assembly (7); the universal adjustment frame (6) is mounted on the gantry bracket (5), the universal adjustment frame (6) can be mounted with the coaxial reflective optical system, and the secondary mirror five-dimensional adjustment tooling assembly (7) is provided on one side of the gantry bracket (5).

2. The coaxial reflective optical system automated assembly and adjustment device according to claim 1, characterized in that: The main mirror assembly (1) comprises a main mirror (101) and a main mirror mounting base (102), wherein the main mirror (101) is fixed to the main mirror mounting base (102) via connecting bolts; The primary and secondary mirror connecting bracket assembly (3) comprises a primary mirror base bracket (301) and a secondary mirror connecting bracket (302), wherein the primary mirror base bracket (301) is connected to the primary mirror mounting base (102), and the secondary mirror connecting bracket (302) is detachably connected to the primary mirror base bracket (301) via a positioning pin and a locking bolt; The secondary mirror assembly (2) comprises a secondary mirror (201), a secondary mirror connecting gasket (202), and a secondary mirror adjusting gasket (203); the secondary mirror connecting gasket (202) and the end face of a secondary mirror connecting bracket (302) are connected via bolts; and the secondary mirror connecting gasket (202), the end face of the secondary mirror connecting bracket (302), the secondary mirror adjusting gasket (203), and the secondary mirror (201) are connected in sequence.

3. The automated assembly and adjustment device for a coaxial reflective optical system according to claim 2, wherein: The standard spherical mirror assembly (4) comprises a standard spherical reflector (401) and a spherical mirror connecting fixture (402), wherein the standard spherical reflector (401) is coaxially mounted with the main mirror assembly (1) via the connecting fixture (402) having an optical axis calibration function; The secondary mirror five-dimensional adjustment tooling assembly (7) comprises a two-axis alignment platform (701), an electric rotating platform (702), an electric lifting platform (703), an electric swing platform (704), a secondary mirror adjustment connection tooling (705) and a contact displacement sensor (706) which are connected in sequence.

4. A method for aligning a coaxial reflective optical system automated alignment device according to any one of claims 1 to 3, comprising the following steps: Step S1, pre-assembling the primary mirror assembly (1) and the secondary mirror assembly (2) through the primary and secondary mirror connecting bracket assembly (3) to form an optical system, and using a dual-light path centering instrument to perform coaxial centering calibration of the primary and secondary mirrors on the optical system; Step S2, mounting the calibrated optical system structure onto a universal adjustment frame (6) on a gantry support (5); Step S3, dismantling the secondary mirror assembly (2), using a laser interferometer in conjunction with a standard spherical reflector assembly (4) to detect the posture of the primary mirror (101) in the primary mirror assembly (1), and adjusting the posture of the primary mirror (101) by a universal adjustment frame (6) so that the optical axis of the primary mirror (101) coincides with the optical axis of the laser interferometer; Step S4, reassembling the secondary mirror assembly (2), and docking the secondary mirror five-dimensional adjustment tooling assembly (7) with the secondary mirror assembly (2); Step S5, using the posture of the primary mirror assembly (1) as a reference, controlling the secondary mirror five-dimensional adjustment fixture assembly (7) through a laser interferometer and using a fuzzy control algorithm to adjust the secondary mirror assembly (2), thereby compensating for the Zernike polynomial coefficients of the wavefront aberration measured by the laser interferometer; Step S6: Fix the primary mirror assembly (1) and the secondary mirror assembly (2) through the primary and secondary mirror connecting bracket assembly (3), thereby completing the assembly and adjustment of the entire optical system.

5. The method for aligning and adjusting a coaxial reflective optical system automatic aligning and adjusting device according to claim 4, characterized in that: Step S1 specifically includes: Step S1-1, detachably connecting the primary mirror base bracket (301) and the secondary mirror connecting bracket (302) via a positioning pin and a locking bolt; Step S1-2: using a dual-light path centering instrument to perform primary and secondary mirror coaxial centering calibration on the primary mirror (101) and the secondary mirror (201), so that the optical axis coaxiality error of the primary mirror (101) and the secondary mirror (201) does not exceed 0.05 mm.

6. The method for aligning and adjusting a coaxial reflective optical system automatic aligning and adjusting device according to claim 5, characterized in that: Step S3 specifically includes: Step S3-1, disassembling the secondary mirror connecting bracket (302) from the primary mirror base bracket (301), so that the secondary mirror assembly (2) is disassembled, and the remaining primary mirror base bracket (301), the primary mirror assembly (1) and the standard spherical mirror assembly (4) are kept in the installation position of the universal adjustment frame (6); Step S3-2, coaxially mounting the standard spherical reflector (401) in the standard spherical reflector assembly (4) with the main mirror assembly (1) through a connecting fixture (402) having an optical axis calibration function; Step S3-3, taking the center of the primary mirror (101) as the origin O of the coordinate system, the direction of the light emitted from the interferometer as the positive direction of the Z axis, and the horizontal direction perpendicular to the Z axis as the X axis to establish a primary mirror coordinate system, moving the spherical mirror connecting fixture (402) along the Z axis, adjusting the focus of the standard spherical reflector (401) to a position conjugate with the focus of the primary mirror (101), and adjusting the posture of the primary mirror (101) through the universal adjustment frame (6) so that the 7th and 8th coefficients of the Zernike polynomial wave aberration coefficient of the primary mirror in the detection result of the laser interferometer are both below 0.

05.

7. The method for aligning and adjusting a coaxial reflective optical system automatic aligning and adjusting device according to claim 6, characterized in that: Step S4 specifically includes: Step S4-1, the secondary mirror connecting bracket (302) is matched with the positioning hole of the primary mirror base bracket (301) using a positioning pin and a tightening bolt with torque control, so that the secondary mirror assembly (2) is reassembled; Step S4-2: three contact displacement sensors (706) monitor in real time the distance values between the contact end faces of the secondary mirror adjustment and connection tooling (705) and the secondary mirror connection gasket (202); when the three distance values are equal, the secondary mirror adjustment and connection tooling (705) and the secondary mirror connection gasket (202) are rigidly connected by tightening bolts; Step S4-3, releasing the cooperation between the primary mirror base bracket (301) and the secondary mirror connecting bracket (302), so that the secondary mirror five-dimensional adjustment fixture assembly (7) can freely adjust the posture of the secondary mirror assembly (2).

8. The method for aligning and adjusting a coaxial reflective optical system automatic aligning and adjusting device according to claim 7, wherein: Step S5 specifically includes: Step S5-1, establishing a matrix model of the five-dimensional adjustment fixture assembly (7) including five-degree-of-freedom motion parameters based on the primary mirror coordinate system; Step S5-2, using a fuzzy control algorithm and a gradient descent algorithm, calculating a compensation amount based on the wavefront aberration data measured by the laser interferometer and controlling the movement of the five-dimensional adjustment tooling assembly (7), so that the coefficients of the 7th and 8th items of the Zernike polynomial wavefront aberration coefficients in the detection results are both less than 0.05; Step S5-3, trimming and grinding the connection gasket in the secondary mirror adjustment assembly according to the motion parameters of the five-dimensional adjustment tooling assembly (7) for controlling the motion.

9. The method for aligning and adjusting a coaxial reflective optical system automatic aligning and adjusting device according to claim 8, characterized in that: In step S5-1, the motion parameters Δx, Δz, θ of each part of the tooling assembly (7) are adjusted according to the five dimensions. y ,Δy,θ x Determine the matrix model R x ,T y ,R y ,T xz ; Wherein, Δx, Δz represent the X-axis and Z-axis translation of the two-axis alignment platform (701), θ y represents the amount of rotation of the electric rotating platform (702) around the Y axis, Δy represents the amount of translation of the electric lifting platform (703) along the Y axis, θ x represents the swing amount of the electric swing table (704) around the X axis, R x ,T y ,R y ,T xz They are respectively the motion matrices of the two-axis alignment platform (701), the electric rotating platform (702), the electric lifting platform (703), and the electric swing platform (704).

10. The method for aligning and adjusting a coaxial reflective optical system automatic aligning and adjusting device according to claim 9, wherein: Step S5-2 specifically includes: Step S5-2-1, using a fuzzy control algorithm, the target position of the secondary mirror (201) is calculated based on the values of the 7th and 8th coefficients of the Zernike polynomial wave aberration coefficients in the detection results; Step S5-2-2: Determine the target transformation matrix T according to the target pose target , define the error function: E=||R x ·T y ·R y ·T xz -T target || F Where E represents the error function, ||·|| F is the Frobenius norm; Use the gradient descent algorithm to minimize E and solve the motion parameters Δx, Δz, θ y ,Δy,θ x The motion parameters obtained by the solution are used to adjust the motion of the five-dimensional adjustment tooling component (7).

Images