Device and method for assisting the adjustment of large-aperture optical elements

Abstract

This invention provides an apparatus and method for assisting in the assembly and adjustment of large-aperture optical components. The main feature is a laser located at the joint of a robotic arm. A grating is used to split the emitted laser beam into at least three point beams. The robotic arm is used to adjust the position of the large-aperture optical component. Iterative adjustment of the optical component is performed using pupil detection and curvature sensing. The position coordinates of the point beams identified by the detectors are transmitted to a computer in real time. The computer corrects joint errors based on these position coordinates through feedback control. This invention achieves multi-degree-of-freedom assembly and adjustment of large-aperture optical components through the combination of pupil and curvature sensing, exhibiting high versatility. By placing a laser at the joint of the robotic arm and using the detectors to provide feedback on the point beam information, assembly and adjustment errors at each joint can be promptly reported. Computer control then progressively eliminates these errors, significantly improving the accuracy of the assembly and adjustment results.

Description

Technical Field

[0001] The invention relates to the technical field of large-aperture optical element adjustment, and specifically provides a device and method for assisting the adjustment of large-aperture optical elements. Background Art

[0002] The booming development of robotics has greatly enriched the processing and assembly methods of large-aperture telescopes. Whether in ground laboratories or in space, robot-assisted assembly has gradually become the main means of assembly, taking on more and more assembly and inspection tasks. Usually, lens assembly methods mostly use simple reciprocating motions such as pushing out and pushing in, with few degrees of freedom. Although this method is stable and easy to control, it is large in size, has poor versatility, and cannot be used for a variety of complex motion scenarios. It cannot be applied to system designs where the actual deviation is greater than the initial state, and has limitations.

[0003] When performing complex multi-degree-of-freedom assembly and adjustment of large-aperture optical components, the robot's assembly accuracy drops sharply, and each section of the robotic arm will introduce an assembly error. As the assembly errors of each section gradually accumulate, the final robot-assisted assembly result is difficult to meet the accuracy requirements of large-aperture optical telescopes.

[0004] Therefore, there is an urgent need for a device method that can reduce or even eliminate the assembly error of each section of the robot. Summary of the invention

[0005] The device provided by the present invention for assisting the adjustment of large-aperture optical elements comprises a multi-section mechanical arm for assisting the adjustment, and is characterized in that a laser is arranged at the joint of the mechanical arm, and the laser emission of the laser is divided into at least three spot light beams by setting a grating.

[0006] Preferably, the emission angles of the point light beams are all different.

[0007] A method for assisting the adjustment of a large-aperture optical element, using a device for assisting the adjustment of a large-aperture optical element to perform multi-degree-of-freedom adjustment on the large-aperture optical element, the steps are as follows:

[0008] S1. Build an assembly and adjustment system, use a robotic arm to control large-aperture optical elements, associate the movement of the robotic arm and joints with their spatial positions through screw theory, and set up detectors on the irradiation plane of the point beam emitted at each joint. Use the detectors to identify the position coordinates of the point beam, and establish a mapping between the position coordinates of the point beam and the spatial position of the joint;

[0009] S2. Use the robotic arm to iteratively adjust the large-aperture optical element. The specific process is as follows:

[0010] When the robot arm controls the large-aperture optical element to perform lateral adjustment, the pupil camera is used to detect the pupil alignment and vignetting of the adjustment system, and the lateral adjustment is determined based on the pupil alignment and vignetting. When the robot arm controls the large-aperture optical element to perform longitudinal adjustment, the curvature sensor is used to detect the wavefront information of the adjustment system, and the longitudinal adjustment is determined based on the wavefront information.

[0011] S3. During the assembly and adjustment process, the detector transmits the position coordinates of the identified point light beam to the computer in real time, and the computer performs error correction on the joint through feedback control based on the position coordinates.

[0012] Preferably, the pupil camera uses edge recognition and contrast measurement to determine and feedback the lateral adjustment status.

[0013] Preferably, the curvature sensor is used to solve the waveform parameters in the adjustment process, and the longitudinal adjustment situation is judged and fed back based on the waveform parameters.

[0014] Preferably, the control principle design process for the robot arm movement is as follows:

[0015] First determine the theoretical position of the large-aperture optical element, then explore the optimal adjustment method to reach this position, and ensure that the robotic arm does not produce position interference and dead points in the process of reaching this position.

[0016] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0017] 1. The present invention realizes the automated auxiliary adjustment of large-aperture optical elements, has a simple structure and high adjustment accuracy.

[0018] 2. Through the combination of pupil and curvature sensing, multi-degree-of-freedom adjustment of large-aperture optical components is achieved, which has high versatility.

[0019] 3. By setting up lasers at the joints of the robotic arm and using the detector to feedback point beam information, the adjustment errors at each joint can be fed back in time, and the adjustment errors can be eliminated step by step through computer control, greatly improving the accuracy of the adjustment results. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a structural diagram of a device for assisting in the installation and adjustment of a large-aperture optical element according to an embodiment of the present invention;

[0021] Figure 2 is a structural diagram of a laser at a joint provided according to an embodiment of the present invention;

[0022] Figure 3 The figure is a flow chart of assembling and adjusting a large-aperture optical element according to an embodiment of the present invention.

[0023] Reference numerals include:

[0024] Large-aperture optical element 1, robotic arm 2, joint 3, laser 31, grating 32, detector 4. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0027] Figure 1 The invention shows a device for assisting in the adjustment of a large-aperture optical element according to an embodiment of the invention.

[0028] like Figure 1 As shown, the device for assisting the installation and adjustment of large-aperture optical elements provided by an embodiment of the present invention is mainly for modifying and optimizing the auxiliary installation and adjustment robot of the existing large-aperture space telescope. The auxiliary installation and adjustment robot has a multi-section robotic arm 2, and joints 3 are arranged between each section of the robotic arm 2, which can ensure that each section of the robotic arm 2 can achieve nearly 360-degree rotation.

[0029] Figure 2 A laser at a joint provided according to an embodiment of the present invention is shown.

[0030] like Figure 2 As shown, a laser 31 is provided at each joint 3, and the emitted laser of the laser 31 is divided into at least three point beams by setting a grating 32. The grating 32 can be integrated on the lens of the laser 31. The emission angles of different point beams are different, ensuring that different point beams are irradiated at different points on the same plane.

[0031] Figure 3 The diagram shows a large-aperture optical element assembly and adjustment process according to an embodiment of the present invention.

[0032] like Figure 3As shown, the method for assisting the adjustment of large-aperture optical elements provided by the embodiment of the present invention mainly utilizes the device for assisting the adjustment of large-aperture optical elements to perform multi-degree-of-freedom adjustment on the large-aperture optical element 1, mainly realizing the lateral adjustment and longitudinal adjustment of the large-aperture optical element 1. The lateral adjustment refers to keeping the distance between the optical elements unchanged and adjusting the concentricity between the optical elements; the longitudinal adjustment refers to keeping the concentricity between the optical elements unchanged and changing the distance between the optical elements through longitudinal adjustment. The specific adjustment steps are as follows:

[0033] S1. Build an assembly and adjustment system, control the gripping end of the robot 2 to fix the large-aperture optical element 1, control the robot 2 section by section from the input end to the gripping end through a computer, and use the large-aperture optical element 1 controlled by the robot 2 to move. The embodiment of the present invention associates the movement of the robot 2 and the joint 3 with their spatial position based on the screw theory, that is, optical measurement is performed through the point spread function. An irradiation plane is selected in the irradiation direction of the point light beam emitted by each joint 3, and a detector 4 is set on each irradiation plane. The point light beam forms a plurality of detection points on the detector 4. The detector identifies the position coordinates of the detection points formed by the point light beam, and establishes a mapping between the position coordinates of the point light beam and the spatial position of the joint 3, that is, the spatial position of the joint 3 can be determined by the position coordinates of the point light beam.

[0034] S2. After the installation and adjustment system is built, the position of the large-aperture optical element 1 is adjusted. The control principle design process for the movement of the robot arm 2 is as follows:

[0035] First, determine the theoretical position of the large-aperture optical element 1, then explore the optimal adjustment method to reach this position, and ensure that the robot 2 does not produce position interference and dead points in the process of reaching this position. The specific control design is a conventional control algorithm design, which belongs to the prior art and will not be described here. The large-aperture optical element 1 is iteratively adjusted by the robot 2, specifically including the following two adjustment forms:

[0036] When the robot 2 controls the large-aperture optical element 1 to perform lateral adjustment, the pupil camera is used to detect the pupil alignment and vignetting of the adjustment system. The pupil camera uses edge recognition and contrast measurement to judge and feedback the lateral adjustment situation. The lateral adjustment situation is judged based on the pupil alignment and vignetting situation. In this process, the movement range of the robot 2 and the joint 3 is large and the accuracy is low. After the lateral adjustment is completed, the longitudinal adjustment is performed.

[0037] When the mechanical arm 2 controls the large-aperture optical element 1 to perform longitudinal adjustment, the curvature sensor is used to detect the wavefront information of the adjustment system, and the longitudinal adjustment situation is judged based on the wavefront information. The curvature sensor is mainly used to solve the waveform parameters in the adjustment process, and the longitudinal adjustment situation is judged and fed back based on the waveform parameters. The curvature sensing range of this process is relatively small and the accuracy is high. After the longitudinal adjustment is completed, the pupil alignment and vignetting are judged, and the above process is iterated repeatedly to gradually improve the position accuracy of the large-aperture optical element 1.

[0038] S3. During the S2 installation and adjustment process, the detector 4 transmits the position coordinates of the identified point light beam to the computer in real time. The computer can determine the spatial position of the robot arm 2 and the joint 3 based on the position coordinates. The installation and adjustment errors of each section of the robot arm 2 and the joint 3 can be calculated by obtaining the spatial positions of the robot arm 2 and the joint 3 and the theoretical position coordinates of the point light beam. The computer then compensates the robot arm 2 and the joint 3 section by section from the input end to the grasping end through feedback control, thereby realizing error correction of the final position of the large-aperture optical element 1 and avoiding the accumulation of installation and adjustment errors of each section.

[0039] The embodiment of the present invention mainly arranges a laser 31 at the joint 3, uses the detector 4 to feedback the point beam information, timely feeds back the adjustment error at each joint 3, and eliminates the adjustment error section by section through computer control, thereby greatly improving the accuracy of the adjustment result, and avoiding the situation in which, when performing multi-degree-of-freedom adjustment, the adjustment error of each section gradually accumulates with the increase of the number of robotic arms 2, and the result of the robot-assisted adjustment is ultimately unable to meet the accuracy requirements of the large-aperture optical telescope.

[0040] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0041] The above specific implementations of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for assisting the adjustment of large-aperture optical elements, characterized in that: A device for assisting the adjustment of large-aperture optical elements is used to perform multi-degree-of-freedom adjustment on large-aperture optical elements. The device for assisting the adjustment of large-aperture optical elements comprises a multi-section mechanical arm for assisting the adjustment. A laser is arranged at the joint of the mechanical arm, and a grating is arranged to divide the emitted laser of the laser into at least three spot light beams. The steps of the method are as follows: S1. Build an assembly and adjustment system, use a robotic arm to control a large-aperture optical element, associate the movement of the robotic arm and joints with their spatial positions through screw theory, and set a detector on the irradiation plane of the point light beam emitted at each joint, identify the position coordinates of the point light beam through the detector, and establish a mapping between the position coordinates of the point light beam and the spatial position of the joint; S2. Iteratively adjust the large-aperture optical element using the mechanical arm. The specific process is as follows: When the mechanical arm controls the large-aperture optical element to perform lateral adjustment, the pupil alignment and vignetting of the adjustment system are detected by using a pupil camera, and the lateral adjustment condition is determined according to the pupil alignment and vignetting conditions; When the mechanical arm controls the large-aperture optical element to perform longitudinal adjustment, the curvature sensor is used to detect the wavefront information of the adjustment system, and the longitudinal adjustment status is determined based on the wavefront information; S3. During the adjustment process, the detector transmits the position coordinates of the identified point light beam to the computer in real time, and the computer performs error correction on the joint through feedback control based on the position coordinates.

2. The method for assisting the adjustment of a large-aperture optical element according to claim 1, characterized in that: The pupil camera uses edge recognition and contrast measurement to determine and feedback the lateral adjustment situation.

3. The method for assisting the adjustment of a large-aperture optical element according to claim 1, characterized in that: The curvature sensor is used to solve the waveform parameters in the adjustment process, and the longitudinal adjustment situation is judged and fed back according to the waveform parameters.

4. The method for assisting the adjustment of a large-aperture optical element according to claim 1, characterized in that: The control principle design process of the robot arm movement is as follows: First, the theoretical position of the large-aperture optical element is determined, and then the optimal adjustment method to reach the position is explored, and it is ensured that the mechanical arm does not produce position interference and dead points in the process of reaching the position.

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