A surface shape measurement system and method for time-controlled grinding of optical elements

Abstract

The present invention discloses a time-controlled grinding surface shape measurement system for optical elements, comprising a bed, the bed being provided with a workpiece mounting seat that moves linearly along the X-axis and a time-controlled grinding processing platform that moves along the Y-axis and the Z-axis, the time-controlled grinding processing platform being provided with a time-controlled grinding processing device, a first measuring device for measuring the displacement change δL2(x, y) of the time-controlled grinding processing platform in the Z-axis direction, and a second measuring device for measuring the distance L3(x, y) from the workpiece surface. Also disclosed is a time-controlled grinding surface shape measurement method for optical elements, comprising the steps of: calibration; error extraction; determination of a measurement starting point and establishment of a measurement coordinate system; and acquisition of actual workpiece surface shape data. The present time-controlled grinding surface shape measurement system and surface shape measurement method for optical elements can realize in-situ measurement of optical element processing, reduce the impact of handling and repeated clamping on workpiece processing accuracy and efficiency, improve measurement efficiency, and achieve integrated processing and detection.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring instruments, and in particular to a time-controlled grinding surface shape measurement system and a surface shape measurement method for an optical element. Background Art

[0002] With the development of fields such as materials science, ultra-precision machining technology and finite element analysis, materials such as fused quartz, K9 glass and single crystal silicon used in optical components have achieved the goal of being more lightweight through structural topology optimization and emerging processing methods. The advancement of ultra-precision machining equipment and processes has made the aperture of machinable single mirrors larger and larger. The aperture of single-sided reflective mirrors has increased from 2-3 meters in the last century to 8-10 meters today. The increase in aperture has greatly improved the imaging quality of the optical system. At the same time, with the development of fields such as large-aperture sub-mirror splicing telescopes and laser fusion, higher requirements are placed on the processing efficiency and processing accuracy of large-aperture optical components.

[0003] The emergence of the concept of time-controlled grinding has created favorable entry conditions for ultra-precision deterministic machining processes (such as magnetorheological and ion beam polishing), significantly reducing the machining allowances caused by machining errors in previous processes, and is expected to increase the machining efficiency of optical components by more than tenfold. To ensure the accuracy and efficiency of time-controlled grinding of large-aperture optical components, the following requirements are placed on workpiece measurement equipment and methods:

[0004] (1) Reduce the number of repeated clamping and handling of workpieces as much as possible;

[0005] (2) The measurable range is greater than 500 mm;

[0006] (3) Measurement accuracy is better than 1μm;

[0007] (4) It should have good measurement adaptability and versatility.

[0008] Existing high-precision measurement methods include swing-arm profilometers and three-coordinate measuring machines (CMMs) with a large measurement range but limited accuracy. Laser interferometry offers extremely high accuracy, but the optical path is less versatile for workpieces with varying surface shapes, requiring the preparation of appropriate lenses and CGH compensators, and placing high demands on workpiece surface quality and the measurement environment. Non-contact high-precision coordinate measuring machines offer excellent measurement accuracy and adaptability, but a limited measurement range. Most importantly, these measuring devices all utilize offline measurement. For large-diameter workpieces subjected to time-controlled grinding, repeated clamping and handling can negatively impact both machining accuracy and efficiency. Therefore, a high-precision, high-efficiency measurement system is needed that can accommodate the unique characteristics of the time-controlled grinding process. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an optical element time-controlled grinding surface measurement system and surface measurement method that can realize in-situ measurement of optical element processing, greatly reduce the impact of the handling and repeated clamping process on the workpiece processing accuracy and efficiency, improve measurement efficiency, achieve integrated processing and detection, and greatly shorten the manufacturing cycle of optical elements.

[0010] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0011] A time-controlled grinding surface shape measurement system for an optical element comprises a bed, wherein the bed is provided with a workpiece mounting seat that performs linear motion along the X-axis and a time-controlled grinding processing platform that moves along the Y-axis and the Z-axis; the time-controlled grinding processing platform is provided with a time-controlled grinding processing device, a first measuring device for measuring the displacement change δL2(x, y) of the time-controlled grinding processing platform in the Z-axis direction, and a second measuring device for measuring the distance L3(x, y) from the workpiece surface.

[0012] As a further improvement of the above technical solution:

[0013] The first measuring device includes a laser interferometer and a reference flat crystal arranged relatively to each other. The laser interferometer is arranged on the time-controlled grinding processing platform, the reference flat crystal is fixed on the bed, and the optical path direction of the laser interferometer is parallel to the Z axis.

[0014] A mounting frame is provided on the bed, and the reference flat crystal is fixed on the mounting frame.

[0015] The second measuring device is a spectral confocal displacement sensor, and the optical path direction of the spectral confocal displacement sensor is parallel to the Z axis.

[0016] The optical path of the laser interferometer is coaxial with the optical path of the spectral confocal displacement sensor.

[0017] The bed is provided with a Y-axis track parallel to the Y-axis, a Y-axis moving seat is slidably provided on the Y-axis track, a Z-axis track parallel to the Z-axis is provided on the Y-axis moving seat, and the time-controlled grinding processing platform is slidably provided on the Z-axis track.

[0018] The bed is provided with an X-axis track parallel to the X-axis, and the workpiece mounting seat is slidably arranged on the X-axis track.

[0019] The workpiece mounting seat includes an X-axis moving table and a workpiece clamping platform rotating around the Z axis. The X-axis moving table is slidably arranged on the X-axis track, and the workpiece clamping platform is arranged on the X-axis moving table.

[0020] The optical element time-controlled grinding surface shape measurement system further includes a numerical control module, and the first measuring device and the second measuring device are both connected to the numerical control module by signal.

[0021] A method for measuring the surface shape of an optical element after time-controlled grinding is performed using the above-mentioned optical element time-controlled grinding surface shape measurement system, comprising the following steps:

[0022] Step S1, calibration: calibrating and calibrating the first measuring device and the second measuring device;

[0023] Step S2, error extraction: extracting the runout error L1(x,y) of the workpiece mounting seat in the Z-axis direction;

[0024] Step S3: determine the measurement starting point and establish a measurement coordinate system;

[0025] Step S4, obtaining the actual data of the workpiece surface shape: inputting the theoretical data of the workpiece surface shape into the numerical control module, obtaining the predetermined running trajectory of the time-controlled grinding platform, the feed rate of the workpiece mounting seat, and the compensation coefficient k, the time-controlled grinding platform and the workpiece mounting seat cooperate to measure the measurement value ΣL(x,y) at each point on the workpiece surface,

[0026] ΣL(x,y)=L1(x,y)+δL2(x,y)+k*L3(x,y), which is the actual data of the workpiece surface shape.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] The present invention's time-controlled grinding surface shape measurement system for optical components measures workpiece surface A directly on the workpiece mounting base after machining, eliminating the need for disassembly. This system enables in-situ measurement of large-aperture optical components, significantly reducing the impact of handling and repeated clamping on workpiece machining accuracy and efficiency. By targeting the specific characteristics of optical components, such as shape, size, target accuracy, and surface quality, the present invention significantly improves measurement efficiency, reduces the environmental, equipment, and labor requirements of the measurement process, and achieves integrated machining and testing, significantly shortening the manufacturing cycle of optical components.

[0029] In the optical element time-controlled grinding surface shape measurement system of the present invention, the first measuring device and the second measuring device can compensate for the motion error of the time-controlled grinding processing platform on the Z axis in real time, further improving the measurement accuracy.

[0030] In the optical element time-controlled grinding surface shape measurement system of the present invention, the optical path of the laser interferometer is coaxial with the optical path of the spectral confocal displacement sensor, thereby minimizing the measured Abbe arm length and improving measurement certainty.

[0031] This time-controlled grinding surface shape measurement method for optical components measures workpiece surface A directly on the workpiece mounting base after machining, eliminating the need for disassembly. This enables in-situ measurement of large-aperture optical components, significantly reducing the impact of handling and repeated clamping on workpiece machining accuracy and efficiency. By addressing the specific characteristics of optical components, such as shape, size, target accuracy, and surface quality, this method significantly improves measurement efficiency, reduces the requirements for the environment, equipment, and manpower during the measurement process, and achieves integrated machining and testing, significantly shortening the manufacturing cycle of optical components. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the three-dimensional structure of the optical element time-controlled grinding surface shape measurement system of the present invention.

[0033] Figure 2 It is a measurement schematic diagram of the first measurement device of the optical element time-controlled grinding surface shape measurement system of the present invention.

[0034] Figure 3 It is a measurement schematic diagram of the second measurement device of the optical element time-controlled grinding surface shape measurement system of the present invention.

[0035] Figure 4 It is a main view of the workpiece measurement track of the optical element time-controlled grinding surface shape measurement system of the present invention.

[0036] Figure 5 It is a top view of the workpiece measurement track of the optical element time-controlled grinding surface shape measurement system of the present invention.

[0037] Figure 6 It is a flow chart of the method for measuring the surface shape of an optical element after time-controlled grinding according to the present invention.

[0038] The numbers in the figure represent:

[0039] 1. Workpiece mounting seat; 11. X-axis moving table; 12. Workpiece clamping platform; 2. Time-controlled grinding platform; 3. Time-controlled grinding device; 4. First measuring device; 41. Laser interferometer; 42. Reference flat crystal; 5. Second measuring device; 6. Bed; 61. Mounting frame; 62. Y-axis track; 63. Y-axis moving seat; 64. Z-axis track; 65. X-axis track; A. Workpiece surface. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1:

[0042] Figures 1 to 5An embodiment of the optical element time-controlled grinding surface shape measurement system of the present invention is shown. The optical element time-controlled grinding surface shape measurement system includes a bed 6, on which is provided a workpiece mounting seat 1 that moves linearly along the X-axis and a time-controlled grinding platform 2 that moves along the Y-axis and Z-axis. The time-controlled grinding platform 2 is provided with a time-controlled grinding device 3, a first measuring device 4 for measuring the displacement change δL2(x,y) of the time-controlled grinding platform 2 in the Z-axis direction, and a second measuring device 5 for measuring the distance L3(x,y) from the workpiece surface A. The workpiece mounting seat 1 is used to mount the workpiece (optical element); the X-axis, Y-axis, and Z-axis are mutually perpendicular and form the three axes of the coordinate system. Generally, the X-axis and Y-axis are the horizontal and vertical axes on the horizontal plane, and the Z-axis is the vertical axis.

[0043] Usage process: First, mount the workpiece (optical element) on the workpiece mounting seat 1, and process the workpiece through the coordinated operation of the time-controlled grinding processing platform 2 and the workpiece mounting seat 1 to form the workpiece surface A; secondly, calibrate and calibrate the first measuring device 4 and the second measuring device 5; then, extract the runout error L1 (x, y) of the workpiece mounting seat 1 in the Z-axis direction, such as vertically fixing the interferometer of the external laser measuring instrument used to measure the motion error on the workpiece mounting seat 1, and fixing the reflector of the external laser measuring instrument on the bed 6. Through repeated fine-tuning, the optical path of the external laser measuring instrument reaches the measuring state, fix the time-controlled grinding processing platform 2, and only retain the movement of the workpiece mounting seat 1 along the X-axis, and record the laser measurement within the movement range of the workpiece mounting seat 1. The data of the instrument are used to obtain the runout error L1(x, y) of the workpiece mounting seat 1 in the Z-axis direction when it moves, which is the vertical straightness error data of the workpiece mounting seat 1 when it moves. L1(x, y) is a function related to the absolute position of the workpiece mounting seat 1, that is, L1(x, y) = f(x), where x is the absolute position of the workpiece mounting seat 1 on the X-axis; then, the predetermined operation trajectory of the time-controlled grinding platform 2, the feed amount and compensation coefficient k of the workpiece mounting seat 1 are obtained through the theoretical data of the workpiece surface shape. The time-controlled grinding platform 2 and the workpiece mounting seat 1 cooperate to operate, and the measurement value ΣL(x, y) at each point of the workpiece surface A is measured, ΣL(x, y) = L1(x, y) + δL2(x, y) + k*L3(x, y), which is the actual data of the workpiece surface shape. If the actual data of the workpiece surface shape meets the processing accuracy requirements, the grinding process is completed; if the actual data of the workpiece surface shape does not meet the processing accuracy requirements, the workpiece is ground and measured again through this optical element time-controlled grinding surface shape measurement system until the actual data of the workpiece surface shape meets the processing accuracy requirements.

[0044] This optical component time-controlled grinding surface shape measurement system measures workpiece surface A directly on workpiece mounting base 1 after machining, eliminating the need to disassemble the workpiece mounting base 1 for measurement. This system enables in-situ measurement of large-aperture optical components, significantly reducing the impact of handling and repeated clamping on workpiece machining accuracy and efficiency. By addressing the specific characteristics of optical components, such as shape, size, target accuracy, and surface quality, this invention significantly improves measurement efficiency, reduces the environmental, equipment, and labor requirements of the measurement process, and achieves integrated machining and testing, significantly shortening the manufacturing cycle of optical components.

[0045] In this embodiment, Figure 1 and Figure 2 As shown, the first measuring device 4 includes a laser interferometer 41 and a reference flat crystal 42 arranged relatively to each other. The laser interferometer 41 is arranged on the time-controlled grinding processing platform 2, and the reference flat crystal 42 is fixed on the bed 6. The optical path direction of the laser interferometer 41 is parallel to the Z axis.

[0046] The laser interferometer 41 is installed on the time-controlled grinding platform 2 and can servo-move along the Z-axis and Y-axis directions along with the time-controlled grinding platform 2. The measurement diagram of the first measuring device 4 is shown in FIG. Figure 2 As shown, the optical path direction of the laser interferometer 41 is parallel to the Z-axis direction. The outgoing light is emitted along the positive direction of the Z-axis, reflected by the high reference flat crystal 42, and the reflected light returns to the laser interferometer 41 along the negative direction of the Z-axis. The interference fringes generated by the emitted and reflected lasers can accurately measure the displacement change of the grinding platform 2 in the Z-axis direction, and the displacement resolution can reach the pm level.

[0047] The runout error L1 (x, y) in the Z-axis direction when the workpiece mounting base 1 moves can also be extracted with the help of the first measuring device 4 , but the measurement accuracy of an external laser measuring instrument is higher.

[0048] In this embodiment, a mounting frame 61 is provided on the bed 6, and the reference flat crystal 42 is fixed on the mounting frame 61. The mounting frame 61 is installed on the bed 6 and does not contact moving parts such as the time-controlled grinding processing platform 2 and the workpiece mounting seat 1. The mounting frame 61 is preferably made of Invar alloy (Invar steel) with an extremely low linear expansion coefficient. The design of isolating the mounting frame 61 from the moving parts ensures that during the measurement process, the mounting frame 61 will not be affected by coupling factors such as vibration, temperature rise, motion error, etc. caused by the operation of other moving parts on the bed 6, thereby maintaining extremely high measurement stability. The mounting frame 61 of the optical element time-controlled grinding surface shape measurement system is separated from other moving parts, so that it is not affected by the coupling factors such as motion error, thermal deformation and vibration of other moving parts during the measurement process, thereby greatly improving the measurement stability.

[0049] In this embodiment, the reference flat crystal 42 is made with the help of wavefront interference measurement method and deterministic processing methods such as magnetorheological fluid and ion beam. The flatness of its reference surface can reach λ / 30-λ / 10 (λ=632.8nm). Compared with the sub-μm measurement accuracy requirement required by the time-controlled grinding processing method, the reference flat crystal 42 can be used as a measurement benchmark.

[0050] The first measuring device 4 and the second measuring device 5 can compensate for the motion error of the time-controlled grinding platform 2 on the Z axis in real time, further improving the measurement accuracy.

[0051] In this embodiment, the second measuring device 5 is a spectral confocal displacement sensor, and the optical path direction of the spectral confocal displacement sensor is parallel to the Z axis.

[0052] The second measuring device 5 is installed on the time-controlled grinding platform 2, and moves along the Z-axis and Y-axis directions with the time-controlled grinding platform 2. Figure 3 As shown, the optical path of the spectral confocal displacement sensor is parallel to the Z-axis. The outgoing light from the spectral confocal displacement sensor is emitted along the negative Z-axis, reflected by workpiece surface A, and then returned to the spectral confocal displacement sensor along the positive Z-axis. Based on the difference in the focal point position of light of different wavelengths, the distance between the second measuring device 5 and the workpiece surface can be calculated with a resolution of up to 80nm. The spectral confocal displacement sensor has better adaptability to measurement surfaces than the laser interferometer 41, and can measure rough surfaces and surfaces with high steepness.

[0053] Due to the working characteristics of the second measuring device 5 (high-precision surface measurement sensor), corresponding compensation is required when measuring workpieces with different steepness. Therefore, the steepness at each measuring position can be obtained based on the theoretical data of the workpiece surface shape, and the corresponding real-time compensation coefficient k of the second measuring device 5 can be obtained.

[0054] In this embodiment, the optical path of the laser interferometer 41 is coaxial with the optical path of the spectral confocal displacement sensor. The coaxiality of the optical path of the laser interferometer 41 and the optical path of the spectral confocal displacement sensor minimizes the measured Abbe arm length and improves measurement certainty.

[0055] Because the range of the second measuring device 5 (spectral confocal displacement sensor) is limited, the time-controlled grinding platform 2 equipped with the second measuring device 5 and the laser interferometer 41 needs to move according to a predetermined trajectory calculated by the theoretical data of the workpiece surface shape to ensure that the distance between the second measuring device 5 and the workpiece surface is always within the range of the second measuring device 5. When the time-controlled grinding platform 2 moves, the laser interferometer 41 continuously measures the precise displacement δL2(x, y) of the time-controlled grinding platform 2 on the Z axis.

[0056] In this embodiment, the bed 6 is provided with a Y-axis track 62 parallel to the Y-axis, a Y-axis moving seat 63 is slidably provided on the Y-axis track 62, a Z-axis track 64 parallel to the Z-axis is provided on the Y-axis moving seat 63, and the time-controlled grinding platform 2 is slidably provided on the Z-axis track 64. The Y-axis moving seat 63 is connected to a Y-axis servo mechanism (not shown in the figure) for driving the Y-axis moving seat 63 to translate along the Y-axis track 62, and the time-controlled grinding platform 2 is connected to a Z-axis servo mechanism (not shown in the figure) for driving the time-controlled grinding platform 2 to translate along the Z-axis track 64.

[0057] In this embodiment, the bed 6 is provided with an X-axis track 65 parallel to the X-axis, and the workpiece mounting seat 1 is slidably mounted on the X-axis track 65. The workpiece mounting seat 1 is connected to an X-axis servo mechanism (not shown) for driving the workpiece mounting seat 1 to translate along the X-axis track 65.

[0058] In this embodiment, the workpiece mounting base 1 includes an X-axis movable table 11 and a workpiece clamping platform 12 that rotates about the Z-axis. The X-axis movable table 11 is slidably mounted on the X-axis rail 65, and the workpiece clamping platform 12 is mounted on the X-axis movable table 11. The workpiece clamping platform 12 is connected to a rotary servo mechanism (not shown) for driving the X-axis movable table 11 to rotate about the Z-axis.

[0059] In this embodiment, the optical element time-controlled grinding surface shape measurement system further includes a numerical control module, to which both the first measuring device 4 and the second measuring device 5 are signal-connected. The numerical control module receives external instructions and / or signal data from the first measuring device 4 and the second measuring device 5 to perform numerical control on the various moving components.

[0060] Example 2:

[0061] Figure 6 An embodiment of the optical element time-controlled grinding surface shape measurement method of the present invention is shown. The optical element time-controlled grinding surface shape measurement method is performed using the optical element time-controlled grinding surface shape measurement system of embodiment 1, and includes the following steps:

[0062] Step S1, calibration: calibrating and calibrating the first measuring device 4 and the second measuring device 5;

[0063] Step S2, error extraction: extracting the runout error L1 (x, y) of the workpiece mounting seat 1 in the Z-axis direction;

[0064] Step S3: determine the measurement starting point and establish a measurement coordinate system;

[0065] Step S4, obtaining actual workpiece surface shape data: inputting theoretical workpiece surface shape data into the numerical control module, obtaining the predetermined running trajectory of the time-controlled grinding platform 2, the feed rate of the workpiece mounting seat 1, and the compensation coefficient k, the time-controlled grinding platform 2 and the workpiece mounting seat 1 cooperate to operate, and measuring the measurement value ΣL(x, y) at each location of the workpiece surface A,

[0066] ΣL(x,y)=L1(x,y)+δL2(x,y)+k*L3(x,y), which is the actual data of the workpiece surface shape.

[0067] The workpiece (optical element) is mounted on the workpiece mounting seat 1. The time-controlled grinding platform 2 and the workpiece mounting seat 1 cooperate to grind the workpiece surface A, and then the surface shape of the workpiece surface A is measured.

[0068] Step S2 includes the following sub-steps:

[0069] Step S2.1: Vertically fix the interferometer of the external laser measuring instrument used to measure motion errors on the workpiece mounting base 1, fix the reflector of the external laser measuring instrument on the bed 6, and repeatedly fine-tune the optical path of the external laser measuring instrument to reach the measurement state;

[0070] Step S2.2: Fix the time-controlled grinding processing platform 2, only retain the movement of the workpiece mounting base 1 along the X-axis, record the data of the laser measuring instrument within the movement range of the workpiece mounting base 1, and obtain the runout error L1(x, y) of the workpiece mounting base 1 in the Z-axis direction when the workpiece mounting base 1 moves, that is, the vertical straightness error data of the workpiece mounting base 1 when the workpiece mounting base 1 moves. L1(x, y) is a function related to the absolute position of the workpiece mounting base 1, that is, L1(x, y) = f(x), where x is the absolute position of the workpiece mounting base 1 on the X-axis.

[0071] Step S4 includes the following sub-steps:

[0072] Step S4.1: Use several planes parallel to the YOZ plane to intercept the workpiece surface A to obtain several curves. The distance between each plane is δX, which is 1 mm in general measurement.

[0073] Step S4.2: The contour curve of a certain section on the workpiece surface A is as follows Figure 4 As shown, the optical element time-controlled grinding surface shape measurement system completes the movement of a predetermined trajectory by the linkage of the time-controlled grinding processing platform 2 in the Z-axis and Y-axis directions. During this movement, the first measuring device 4 and the second measuring device 5 continuously collect data to complete the measurement of the curved profile on a cross section of the workpiece surface A;

[0074] Because the range of the second measuring device 5 (spectral confocal displacement sensor) is limited, the time-controlled grinding platform 2, equipped with the second measuring device 5 and the first measuring device 4, must move along a predetermined trajectory calculated based on theoretical workpiece surface topography data to ensure that the distance between the second measuring device 5 and the workpiece surface remains within the measuring range of the second measuring device 5. As the time-controlled grinding platform 2 moves, the first measuring device 4 continuously measures the precise displacement δL2(x,y) of the time-controlled grinding platform 2 on the Z axis. Using the theoretical workpiece surface topography data, the predetermined trajectory of the time-controlled grinding platform 2, the feed rate of the workpiece mounting base 1, and the compensation coefficient k are determined.

[0075] Step S4.3: The workpiece mounting seat 1 is fed δX, and the time-controlled grinding platform 2 moves to the starting point of the next section of the workpiece under the linkage of the Z axis and the Y axis. Repeat step S4.2: Complete the contour measurement on the subsequent section of the workpiece. The trajectory of the measurement process in the XOY plane is as follows Figure 5 As shown;

[0076] Step S4.4: The actual measurement results at each location include four components: the vertical straightness error L1(x, y) of the workpiece mounting base 1, the displacement change δL2(x, y) of the time-controlled grinding platform 2 in the Z-axis direction as fed back by the first measuring device 4, the distance L3(x, y) between the second measuring device 5 and the workpiece surface A as measured by the second measuring device 5, and the compensation coefficient k corresponding to the different steepness of the workpiece surface A. The final measurement value ΣL(x, y) at each location on the workpiece surface A is:

[0077] ΣL(x,y)=L1(x,y)+δL2(x,y)+k*L3(x,y), which is the actual data of the workpiece surface shape.

[0078] Step S4.5: The measurement data is converted into an xyz three-dimensional point cloud image through the CNC module, and subsequent evaluation of various indicators is performed.

[0079] This method for measuring the surface shape of optical components after time-controlled grinding measures workpiece surface A directly on workpiece mounting base 1 after machining, eliminating the need to disassemble the workpiece from mounting base 1. This enables in-situ measurement of large-aperture optical components, significantly reducing the impact of handling and repeated clamping on workpiece machining accuracy and efficiency. By addressing the specific characteristics of optical components, such as shape, size, target accuracy, and surface quality, this method significantly improves measurement efficiency, reduces the requirements for the environment, equipment, and manpower during the measurement process, and achieves integrated machining and testing, significantly shortening the manufacturing cycle of optical components.

[0080] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for measuring the surface shape of an optical component during time-controlled grinding, characterized in that: The optical element time-controlled grinding surface shape measurement system is used, and the optical element time-controlled grinding surface shape measurement system includes a bed (6) and a numerical control module. The bed (6) is provided with a workpiece mounting seat (1) that moves linearly along the X axis and a time-controlled grinding processing platform (2) that moves along the Y axis and the Z axis. The time-controlled grinding processing platform (2) is provided with a time-controlled grinding processing device (3), a first measuring device (4) for measuring the displacement change δL2(x, y) of the time-controlled grinding processing platform (2) in the Z axis direction, and a second measuring device (5) for measuring the distance L3(x, y) from the workpiece surface (A). The first measuring device (4) and the second measuring device (5) are both connected to the numerical control module signal. The optical element time-controlled grinding surface shape measurement method includes the following steps: Step S1, calibration: calibrating and calibrating the first measuring device (4) and the second measuring device (5); Step S2, extracting error: extracting the runout error L1(x,y) of the workpiece mounting seat (1) in the Z-axis direction; Step S3: determine the measurement starting point and establish a measurement coordinate system; Step S4, obtaining the actual data of the workpiece surface shape: inputting the theoretical data of the workpiece surface shape into the numerical control module, obtaining the predetermined running trajectory of the time-controlled grinding platform (2), the feed rate and the compensation coefficient k of the workpiece mounting seat (1), the time-controlled grinding platform (2) and the workpiece mounting seat (1) cooperate to operate, and measuring the measurement value ΣL(x,y) at each location of the workpiece surface (A), ΣL(x,y)=L1(x,y)+δL2(x,y)+k*L3(x,y), which is the actual data of the workpiece surface shape.

2. An optical element time-controlled grinding surface shape measurement system, characterized by: The method for measuring the surface shape of an optical element after time-controlled grinding according to claim 1 comprises a bed (6), wherein the bed (6) is provided with a workpiece mounting seat (1) that moves linearly along the X-axis and a time-controlled grinding platform (2) that moves along the Y-axis and the Z-axis, wherein the time-controlled grinding platform (2) is provided with a time-controlled grinding device (3), a first measuring device (4) for measuring the displacement change δL2(x, y) of the time-controlled grinding platform (2) in the Z-axis direction, and a second measuring device (5) for measuring the distance L3(x, y) from the workpiece surface (A).

3. The optical element time-controlled grinding surface shape measurement system according to claim 2, characterized in that: The first measuring device (4) comprises a laser interferometer (41) and a reference flat crystal (42) arranged relative to each other, the laser interferometer (41) being arranged on the time-controlled grinding platform (2), the reference flat crystal (42) being fixed on the bed (6), and the optical path direction of the laser interferometer (41) being parallel to the Z axis.

4. The optical element time-controlled grinding surface shape measurement system according to claim 3, characterized in that: A mounting frame (61) is provided on the bed (6), and the reference flat crystal (42) is fixed on the mounting frame (61).

5. The optical element time-controlled grinding surface shape measurement system according to claim 4, characterized in that: The second measuring device (5) is a spectral confocal displacement sensor, and the optical path direction of the spectral confocal displacement sensor is parallel to the Z axis.

6. The optical element time-controlled grinding surface shape measurement system according to claim 5, characterized in that: The optical path of the laser interferometer (41) is coaxial with the optical path of the spectral confocal displacement sensor.

7. The optical element time-controlled grinding surface shape measurement system according to any one of claims 2 to 6, characterized in that: The bed (6) is provided with a Y-axis track (62) parallel to the Y-axis, a Y-axis moving seat (63) is slidably provided on the Y-axis track (62), a Z-axis track (64) parallel to the Z-axis is provided on the Y-axis moving seat (63), and the time-controlled grinding processing platform (2) is slidably provided on the Z-axis track (64).

8. The optical element time-controlled grinding surface shape measurement system according to any one of claims 2 to 6, characterized in that: An X-axis track (65) parallel to the X-axis is provided on the bed (6), and the workpiece mounting seat (1) is slidably arranged on the X-axis track (65).

9. The optical element time-controlled grinding surface shape measurement system according to claim 8, characterized in that: The workpiece mounting seat (1) comprises an X-axis moving table (11) and a workpiece fixture platform (12) rotating about a Z axis, wherein the X-axis moving table (11) is slidably mounted on an X-axis track (65), and the workpiece fixture platform (12) is mounted on the X-axis moving table (11).

10. The optical element time-controlled grinding surface shape measurement system according to any one of claims 2 to 6, characterized in that: The optical element time-controlled grinding surface shape measurement system further comprises a numerical control module, and the first measuring device (4) and the second measuring device (5) are both connected to the numerical control module by signal.

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