Hemispherical harmonic oscillator grinding process optimization method based on laser Doppler vibration meter

Abstract

The invention discloses a hemispherical harmonic oscillator grinding process optimization method based on a laser Doppler vibration meter, relates to the technical field of ultra-precision machining, and aims to solve the problems of difficulty in tool setting of a small-diameter ball head grinding wheel and a hemispherical harmonic oscillator blank and difficulty in real-time monitoring of the grinding condition in the machining process in an existing method. Comprising the steps that a hemispherical harmonic oscillator grinding machine tool is controlled to enable a small-diameter ball head grinding wheel to approach all key parts on the surface of the hemispherical harmonic oscillator to conduct tool setting operation, a laser Doppler vibration meter collects vibration signals of the hemispherical harmonic oscillator, tool setting position coordinates are determined according to the occurrence moment of the vibration signals, and a small-diameter ball head grinding wheel machining track of the hemispherical harmonic oscillator is constructed; the hemispherical harmonic oscillator is ground according to the grinding wheel machining track, the vibration signal of the hemispherical harmonic oscillator in the grinding process is collected through the laser Doppler vibration meter, the grinding state of the hemispherical harmonic oscillator is analyzed according to the specific frequency in the vibration signal, and the method is easy and convenient to implement and high in accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-precision machining, and in particular to a method for optimizing a hemispherical resonator grinding process based on a laser Doppler vibrometer. Background Art

[0002] With the rapid advancement of science and technology, curved parts with complex structures, miniaturization, and high machining requirements are playing an increasingly important role in key components in aerospace, military defense, optical components, microelectronics, and other fields. The hemispherical resonator gyroscope (HRG) is currently the most precise solid-state vibratory gyroscope and is considered a disruptive technology, with the greatest potential to rival or even replace optical gyroscopes in the future. It can meet the long-endurance requirements of the next generation of inertial devices and offers advantages such as ultra-high precision, high reliability, and long life. The core component of a HRG is the resonator, a thin-walled hemispherical shell consisting of a central rod and a hemispherical thin-walled shell. Made of fused quartz, it is ground using a small-diameter ball-end grinding wheel. Because fused quartz is a typically hard and brittle material, and to ensure the high geometric accuracy of the HRG, tool setting with a small-diameter ball-end grinding wheel and programming are required before machining, and real-time monitoring of the grinding progress is required during the process.

[0003] At present, the research on the processing of hemispherical resonators is still in the exploratory stage, and there is little research on the optimization of the grinding process of hemispherical resonators. Although ultra-precision grinding machines for processing high-precision hemispherical resonators have been developed, there are still many functions that need to be improved in their intelligent upgrading; the existing hemispherical resonator grinding methods mainly rely on experienced experimenters to perform tool setting and deterministic material removal judgments, which have high labor costs and are greatly affected by subjective factors. It is difficult to ensure the uniformity of the quality of the hemispherical resonator after processing, and it is difficult to realize the analysis of different stages of the ultra-precision grinding process of hemispherical resonators. Summary of the Invention

[0004] The technical problems to be solved by the present invention are:

[0005] The existing hemispherical resonator grinding method has the problems of difficulty in aligning the small-diameter ball-end grinding wheel with the hemispherical resonator blank and difficulty in real-time monitoring of the grinding condition during the processing.

[0006] The present invention is to solve the above technical problems using the following technical solutions:

[0007] The present invention provides a method for optimizing a hemispherical resonator grinding process based on a laser Doppler vibrometer. The method is based on a processing system integrating a laser Doppler vibrometer and a hemispherical resonator grinding machine tool, and includes the following steps:

[0008] S100, draw the outline of the workpiece cross section and clamp the small diameter ball head grinding wheel onto the grinding wheel spindle;

[0009] S200, determining the Z-axis tool setting initial data Z0 in which the center of the grinding wheel ball head and the central axis of the hemispherical resonator support rod are at the same horizontal height;

[0010] S300, clamping the hemispherical resonator to be processed onto the workpiece spindle;

[0011] S400, controlling the hemispherical resonator grinding machine tool so that the small-diameter ball-end grinding wheel approaches key locations on the surface of the hemispherical resonator to perform tool setting operations, collecting the vibration signal of the hemispherical resonator through a laser Doppler vibrometer, and determining the tool setting position coordinates based on the time when the vibration signal appears;

[0012] S500, constructing a small-diameter ball-end grinding wheel machining trajectory of a hemispherical resonator according to the coordinates of each tool setting position;

[0013] S600: Grind the hemispherical resonator according to the grinding wheel machining trajectory, collect the vibration signal of the hemispherical resonator during the grinding process by using a laser Doppler vibrometer, and analyze the grinding state of the hemispherical resonator according to a specific frequency in the vibration signal.

[0014] Furthermore, S100 also includes: measuring the radial runout of the small-diameter ball-end grinding wheel by using a micrometer, and making the center of the small-diameter ball-end grinding wheel coincide with the rotation axis of the grinding wheel spindle by repeatedly clamping.

[0015] Furthermore, S300 also includes: measuring the radial runout of the hemispherical resonator at different positions by using a micrometer, and making the axis of the hemispherical resonator support rod coincide with the rotation axis of the workpiece spindle by repeated clamping.

[0016] Furthermore, the key parts of the surface of the hemispherical resonator in S400 include: the inner rod end surface of the hemispherical resonator support rod, the inner rod side surface of the support rod, the outer rod side surface of the support rod, the inner spherical shell contour surface, the outer spherical shell contour surface, and the inner and outer fillets of the hemispherical shell.

[0017] Furthermore, S400 includes the following steps:

[0018] The hemispherical resonator grinding machine is controlled to make the small-diameter ball-end grinding wheel approach the inner rod end face, inner rod side face and outer rod side face of the hemispherical resonator support rod for tool setting operation. The vibration signal of the support rod is collected by a laser Doppler vibrometer, and the coordinates of each tool setting position are determined according to the time when the vibration signal appears. The same operation is used to determine the two tool setting position coordinates on the inner spherical shell surface of the hemispherical resonator, the two tool setting position coordinates on the outer spherical shell surface and the tool setting position coordinates of the inner and outer fillets of the hemispherical shell.

[0019] Furthermore, S500 includes the following steps:

[0020] S510, connecting the two tool setting positions on the inner spherical shell surface and the two tool setting positions on the outer spherical shell surface and drawing perpendicular midlines respectively, the intersection points of the two perpendicular midlines and the workpiece axis being the centers of the inner and outer spherical shell surfaces, respectively, and drawing the machining trajectories of the inner and outer spherical shell surfaces;

[0021] S520, drawing a line parallel to the workpiece rotation axis through the tool position on the inner rod side to obtain a machining trajectory of the inner rod, and drawing a line parallel to the workpiece rotation axis through the tool position on the outer rod side to obtain a machining trajectory of the outer rod;

[0022] S530: Draw an arc tangent to the inner rod machining trajectory and the inner spherical shell surface machining trajectory through the inner fillet tool setting position to obtain the inner fillet machining trajectory; draw an arc tangent to the outer rod machining trajectory and the outer spherical shell machining trajectory through the outer fillet tool setting position to obtain the outer fillet machining trajectory;

[0023] S540, connecting each processing trajectory to obtain a small-diameter ball-end grinding wheel processing trajectory of the hemispherical resonator.

[0024] Furthermore, the specific frequencies in S600 include 5431 Hz and 7519 Hz.

[0025] Furthermore, the analysis of the hemispherical resonator grinding processing status described in S600 includes: judging the moment when the ball-end grinding wheel and the hemispherical resonator are completely ground based on whether a specific frequency appears; if an abnormal frequency different from the specific frequency appears during the processing, it indicates that the small-diameter ball-end grinding wheel is worn and needs to be shut down for processing.

[0026] Furthermore, the collecting of the vibration signal of the hemispherical resonator during the grinding process by the laser Doppler vibrometer in S600 specifically involves collecting the vibration signal of the lip edge of the hemispherical resonator during the grinding process by the laser Doppler vibrometer.

[0027] Furthermore, the processing system includes a hemispherical resonator grinding machine and a laser Doppler vibrometer, wherein the hemispherical resonator grinding machine includes a machine bed, an X-axis linear motion platform, a Y-axis linear motion platform, a Z-axis linear motion platform, a C-axis turntable, a U-axis micro-displacement platform, a workpiece spindle, a grinding wheel spindle, a CCD camera, a triangular connecting frame, a fixed frame and a workbench;

[0028] An X-axis linear motion platform, a Y-axis linear motion platform, and a Z-axis linear motion platform are installed on the machine tool bed. The X-axis linear motion platform and the Y-axis linear motion platform are stacked in a cross shape, and the Z-axis linear motion platform is installed perpendicular to the X-axis linear motion platform and the Y-axis linear motion platform, together forming a spatial rectangular coordinate system;

[0029] The workbench is mounted on an X-axis linear motion platform and a Y-axis linear motion platform;

[0030] The workpiece spindle is installed on the workbench, and the direction of the rotation axis is parallel to the Y axis;

[0031] The CCD camera is connected to the workbench via a micro-displacement module;

[0032] The C-axis turntable is mounted on the Z-axis linear motion platform via a triangular connecting frame, and the rotation axis of the C-axis turntable is parallel to the Z-axis;

[0033] The U-axis micro-displacement platform is mounted on the C-axis turntable;

[0034] The grinding wheel spindle is mounted on the U-axis micro-displacement platform through a fixed frame, wherein the angle between the grinding wheel spindle and the U-axis micro-displacement platform is 40°;

[0035] The laser Doppler vibrometer is installed on a workbench through a supporting frame.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The present invention uses a laser Doppler vibrometer to collect vibration data of a hemispherical resonator in real time, performs tool alignment and constructs a processing trajectory based on the vibration data, collects the vibration signal of the hemispherical resonator during the grinding process through the laser Doppler vibrometer, and analyzes the grinding processing status of the hemispherical resonator based on the specific frequency in the vibration signal. The method of the present invention is simple, easy to use and has high accuracy.

[0038] (2) The method of the present invention utilizes the ball-end grinding wheel machining trajectory to compile the machining program, which does not require precise measurement of the specific size of the grinding wheel, thereby reducing the error in the ultra-precision machining process.

[0039] (3) The method of the present invention obtains vibration data in real time through a laser Doppler vibrometer, which can accurately detect the grinding stage and grinding time, and at the same time, can avoid the influence of processing accuracy due to excessive wear of the grinding wheel.

[0040] (4) The method of the present invention has a certain universality and can be extended to optimize the process of ultra-precision grinding and polishing of rotating parts with spherical structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the structure of the processing system in the embodiment of the present invention Figure 1 ;

[0042] Figure 2 Schematic diagram of the structure of a hemispherical resonator grinding machine tool in an embodiment of the present invention;

[0043] Figure 3 Schematic diagram of tool setting points in an embodiment of the present invention;

[0044] Figure 4is a curve of the motion trajectory of the grinding wheel center when machining the inner and outer spherical surfaces in an embodiment of the present invention;

[0045] Figure 5 This is the grinding and polishing trajectory of the hemispherical resonator ball-end grinding wheel in the embodiment of the present invention;

[0046] Figure 6 This is a diagram showing the sudden change in vibration signal of the laser Doppler vibrometer before and after the hemispherical resonator tool setting contact in an embodiment of the present invention;

[0047] Figure 7 This is a specific frequency diagram corresponding to the vibration generated by the hemispherical resonator during normal grinding in an embodiment of the present invention;

[0048] Figure 8 This is a vibration frequency diagram of the hemispherical resonator when the grinding wheel in the embodiment of the present invention is severely worn.

[0049] Description of reference numerals:

[0050] 1-Laser Doppler vibrometer, 2-Measuring laser, 3-Workpiece spindle, 4-X-axis motion platform, 5-Y-axis motion platform, 6-Grinding wheel spindle, 7-U-axis micro-displacement platform, 8-C-axis turntable, 9-Z-axis motion platform, 10-CCD camera, 11-Hemispherical resonator. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the present invention, exemplary embodiments or examples of the present invention will be described below with reference to the accompanying drawings. Obviously, the described embodiments or examples are only some of the embodiments or examples of the present invention, and not all of them. Based on the embodiments or examples of the present invention, all other embodiments or examples obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0053] Specific embodiment 1: The present invention provides a method for optimizing a hemispherical resonator grinding process based on a laser Doppler vibrometer. The method is based on a processing system integrating a laser Doppler vibrometer 1 and a hemispherical resonator grinding machine tool, and includes the following steps:

[0054] S100. Preliminarily measure the workpiece size based on the hemispherical resonator blank structure diagram and the micrometer, draw the outline of the workpiece cross section in the CAD software, and clamp the small-diameter ball-end grinding wheel onto the grinding wheel spindle 6; during the movement of the machine tool, it is necessary to ensure that the extension line of the rotation axis of the C-axis turntable 8 coincides with the center of the grinding wheel; the length of the small-diameter ball-end grinding wheel rod is 40 mm, and the length of the grinding wheel rod exposed from the grinding wheel spindle 6 is different after each clamping.

[0055] S200, define the C-axis as 0° when the grinding wheel axis and the hemispherical resonator support rod axis are in the same vertical plane, and define the C-axis as the positive direction when the C-axis rotates clockwise. With the help of the industrial CCD camera 10, adjust the U-axis micro-displacement platform 7 so that the center of the small-diameter ball-end grinding wheel remains unchanged when the C-axis is at 0° and 90°. At this time, the extension line of the C-axis rotation axis coincides with the center of the grinding wheel. Based on the angle of 40° between the workpiece spindle 3 and the U-axis, the displacement data of the U-axis micro-displacement platform 7, and the relative position relationship between the C-axis turntable 8, the U-axis micro-displacement platform 7, the workpiece spindle 3, and the grinding wheel spindle 6, calculate the Z-axis tool setting initial data Z0;

[0056] S300, clamping the hemispherical resonator to be processed onto the workpiece spindle 3;

[0057] S400, maintaining the Z-axis linear motion platform 9 at the Z0 position, rotating the small-diameter ball-end grinding wheel at a certain speed, and keeping the hemispherical resonator stationary, controlling the grinding machine tool so that the small-diameter ball-end grinding wheel approaches key locations on the surface of the hemispherical resonator for tool setting operations, collecting the vibration signal of the hemispherical resonator using the laser Doppler vibrometer 1, and determining the tool setting position coordinates based on the time when the vibration signal appears;

[0058] S500, constructing a small-diameter ball-end grinding wheel machining trajectory of a hemispherical resonator according to the coordinates of each tool setting position;

[0059] S600. Calculate the coordinates of the characteristic points of each trajectory relative to the machine tool origin, further compile a machine tool processing program, and perform ultra-precision grinding on the hemispherical resonator. During the grinding process, the light beam of the laser Doppler vibrometer 1 is vertically irradiated on the hemispherical resonator. The laser Doppler vibrometer 1 collects the vibration signal of the hemispherical resonator during the grinding process, and analyzes the grinding status of the hemispherical resonator based on the specific frequency in the vibration signal.

[0060] Specific implementation scheme 2: S100 further includes: measuring the radial runout of the small-diameter ball-end grinding wheel with a dial indicator, and repeatedly clamping the small-diameter ball-end grinding wheel so that the center of the small-diameter ball-end grinding wheel coincides with the rotation axis of the grinding wheel spindle 6. The rest of this implementation scheme is the same as the specific implementation scheme 1.

[0061] Specific implementation plan three: S300 also includes: measuring the radial runout of the hemispherical resonator at different positions with a dial indicator, and repeatedly clamping the hemispherical resonator support rod to coincide with the rotation axis of the workpiece spindle 3. This implementation plan is otherwise the same as the specific implementation plan two.

[0062] Specific Implementation Method 4: The key areas of the hemispherical resonator surface described in S400 include: the inner end faces of the hemispherical resonator support rods, the inner side faces of the support rods, the outer side faces of the support rods, the contour surface of the inner spherical shell, the contour surface of the outer spherical shell, and the inner and outer fillets of the hemispherical shell. This implementation method is otherwise identical to Specific Implementation Method 3.

[0063] Specific implementation plan five: Figure 3 As shown, S400 includes the following steps:

[0064] Keep the Z-axis linear motion platform 9 at the Z0 position, make the small diameter ball head grinding wheel rotate at a certain speed, and the hemispherical resonator stand still. Control the machine tool to make the small diameter ball head grinding wheel approach the inner rod end face point 0 of the hemispherical resonator support rod, the inner rod side point 1 of the support rod, and the outer rod side point 7 of the support rod to perform tool setting operation. The beam of the laser Doppler vibrometer 1 is vertically irradiated on the support rod. When the small diameter ball head grinding wheel contacts the hemispherical resonator support rod, the hemispherical resonator is forced to vibrate. When the vibration signal suddenly changes, the machine tool stops. The position of each axis of the machine bed is the tool setting position of that point; using the same operation, control the machine tool so that the small diameter ball head grinding wheel approaches two points 2 and 3 on the inner shell surface of the hemispherical resonator, two points 5 and 6 on the outer shell surface, one point 4 on the end surface of the hemispherical shell, and the inner and outer corner points 9 and 8 of the hemispherical shell to perform tool setting operations. The light beam of the laser Doppler vibrometer 1 is vertically irradiated on the hemispherical shell. When the small diameter ball head grinding wheel contacts the hemispherical resonator shell, the hemispherical resonator is forced to vibrate, and the vibration signal of the laser Doppler vibrometer 1 will show a sudden change, such as Figure 6 As shown, the position of each axis of the machine tool at this time is the tool setting position of that point, and the X and Y coordinate values ​​of each contact point are recorded. The rest of this embodiment is the same as the specific embodiment four.

[0065] Specific implementation plan six: Figure 4 and Figure 5 As shown, S500 includes the following steps:

[0066] S510, connecting the two tool setting positions 2 and 3 on the inner spherical shell surface and the two tool setting positions 5 and 6 on the outer spherical shell surface and drawing perpendicular midlines respectively. The intersection points of the two perpendicular midlines and the workpiece axis are the centers of the inner and outer spherical shell surfaces, respectively. Draw an arc with the distance between the center of the circle and the tool setting point as the radius to obtain the machining trajectory of the inner and outer spherical shell surfaces;

[0067] S520, draw a line parallel to the workpiece rotation axis through tool setting position point 1 on the inner rod side to obtain a machining trajectory of the inner rod, and draw a line parallel to the workpiece rotation axis through tool setting position point 7 on the outer rod side to obtain a machining trajectory of the outer rod;

[0068] S530: Draw an arc tangent to the inner rod machining trajectory and the inner spherical shell surface machining trajectory through the inner fillet tool setting position 9 to obtain the inner fillet machining trajectory. Draw an arc tangent to the outer rod machining trajectory and the outer spherical shell machining trajectory through the outer fillet tool setting position 8 to obtain the outer fillet machining trajectory.

[0069] S540, connecting each processing trajectory to obtain a small-diameter ball-end grinding wheel processing trajectory of the hemispherical resonator.

[0070] S600 includes the following steps:

[0071] Mount the S610 laser Doppler vibrometer 1 on a workbench using a support bracket. Adjust the laser spot of the laser vibrometer 1 to illuminate the lip edge of the resonator to maximize the amplitude. First, use autofocus to focus the laser spot. Then, manually adjust the focus knob on the rear of the laser according to the signal strength displayed on the front of the vibrometer until the signal strength is optimal.

[0072] S620, starting the grinding process, when the small diameter ball end grinding wheel grinds the hemispherical resonator, the hemispherical resonator is vibrated, and the vibration data of the hemispherical resonator is collected in real time by the laser Doppler vibrometer 1;

[0073] S630, process the vibration data using the software of the laser Doppler vibrometer 1 and draw a spectrum diagram. The rest of this embodiment is the same as the specific embodiment five.

[0074] Specific implementation plan seven: Figure 7 As shown, the specific frequencies in S600 include 5431 Hz and 7519 Hz. The rest of this embodiment is the same as the specific embodiment six.

[0075] Specific implementation scheme eight: Analyzing the grinding processing state of the hemispherical resonator as described in S600 includes: judging the moment when the ball-end grinding wheel and the hemispherical resonator are completely ground according to whether a specific frequency appears; Figure 8 As shown, if an abnormal frequency different from the specific frequency appears during the machining process, it indicates that the small-diameter ball-end grinding wheel is worn and needs to be shut down for processing. The method also includes: performing a wavelet transform on the vibration signal data during the grinding process to obtain a time-frequency scale diagram. Based on the scale changes of the specific frequency, the grinding time and grinding ratio of the ball-end grinding wheel and the hemispherical resonator are determined in real time, and the different stages of the hemispherical resonator ultra-precision grinding process are analyzed.

[0076] The determination of the grinding ratio is as follows:

[0077]

[0078] When the grinding ratio is 100%, the hemispherical resonator can be subjected to deterministic material removal to ensure the uniformity and uniformity of the surface quality of the hemispherical resonator, providing a basis for deterministic material removal in the next step of ultra-precision grinding.

[0079] Specific implementation scheme nine: The laser Doppler vibrometer 1 is used to collect the vibration signal of the hemispherical resonator during the grinding process as described in S600. Specifically, the laser Doppler vibrometer 1 is used to collect the vibration signal of the lip edge of the hemispherical resonator during the grinding process. This implementation scheme is otherwise the same as the specific implementation scheme eight.

[0080] Specific implementation plan 10: Figure 1 and 2 As shown, the processing system includes a hemispherical resonator grinding machine and a laser Doppler vibrometer 1. The hemispherical resonator grinding machine includes a machine bed, an X-axis linear motion platform 4, a Y-axis linear motion platform 5, a Z-axis linear motion platform 9, a C-axis turntable 8, a U-axis micro-displacement platform 7, a workpiece spindle 3, a grinding wheel spindle 6, a CCD camera 10, a triangular connecting frame, a fixed frame and a workbench;

[0081] An X-axis linear motion platform 4, a Y-axis linear motion platform 5, and a Z-axis linear motion platform 9 are installed on the machine tool bed. The X-axis linear motion platform 4 and the Y-axis linear motion platform 5 are installed in a cross-stacked manner. The Z-axis linear motion platform 9 is installed perpendicular to the X-axis linear motion platform 4 and the Y-axis linear motion platform 5, and together form a spatial rectangular coordinate system.

[0082] The workbench is installed on the X-axis linear motion platform 4 and the Y-axis linear motion platform 5;

[0083] The workpiece spindle 3 is mounted on the workbench, and the direction of the rotation axis is parallel to the Y axis;

[0084] The CCD camera 10 is connected to the workbench via a micro-displacement module;

[0085] The C-axis turntable 8 is mounted on the Z-axis linear motion platform 9 via a triangular connecting frame, and the rotation axis direction of the C-axis turntable 8 is parallel to the Z-axis;

[0086] The U-axis micro-displacement platform 7 is installed on the C-axis turntable 8;

[0087] The grinding wheel spindle 6 is mounted on the U-axis micro-displacement platform 7 through a fixed frame, wherein the angle between the grinding wheel spindle 6 and the U-axis micro-displacement platform 7 is 40°;

[0088] The laser Doppler vibrometer 1 is installed on a workbench via a support frame.

[0089] The laser Doppler vibrometer is a Vibroflex laser Doppler vibrometer from Polytec. It can measure displacement, velocity or acceleration according to actual conditions, has a good signal-to-noise ratio, and can be remotely automatically focused. Its supporting software has waveform acquisition and display, unit conversion, line-adjustable fast Fourier transform (FFT), data storage and export functions. The vibration waveform, amplitude-frequency characteristic curve and frequency peak can be observed intuitively in the software. Adjust the laser point of the laser vibrometer to illuminate the lip edge of the hemispherical resonator to ensure the maximization of the amplitude. First, focus the laser point using the automatic focus method, and then manually adjust the focus knob behind the laser according to the signal strength displayed on the front end of the vibrometer until the signal strength is optimal. The rest of this implementation plan is the same as the specific implementation plan nine.

[0090] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art of the present invention may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for optimizing a hemispherical resonator grinding process based on a laser Doppler vibrometer, characterized in that: The method is based on a processing system integrating a laser Doppler vibrometer (1) and a hemispherical resonator grinding machine tool, and comprises the following steps: S100, drawing the outline of the workpiece cross section, and clamping the small-diameter ball-end grinding wheel onto the grinding wheel spindle (6); S200, determining the Z-axis tool setting initial data Z0 in which the center of the grinding wheel ball head and the central axis of the hemispherical resonator support rod are at the same horizontal height; S300, clamping the hemispherical resonator to be processed onto the workpiece spindle (3); S400, controlling the hemispherical resonator grinding machine to make the small-diameter ball-end grinding wheel approach key positions on the surface of the hemispherical resonator to perform tool setting operations, collecting the vibration signal of the hemispherical resonator through the laser Doppler vibrometer (1), and determining the tool setting position coordinates according to the time when the vibration signal appears; S500, constructing a small-diameter ball-end grinding wheel machining trajectory of a hemispherical resonator according to the coordinates of each tool setting position; S600, grinding the hemispherical resonator according to the grinding wheel machining trajectory, collecting the vibration signal of the hemispherical resonator during the grinding process by using a laser Doppler vibrometer (1), and analyzing the grinding state of the hemispherical resonator according to a specific frequency in the vibration signal.

2. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 1, characterized in that: S100 also includes: measuring the radial runout of the small-diameter ball-end grinding wheel by using a micrometer, and making the center of the small-diameter ball-end grinding wheel coincide with the rotation axis of the grinding wheel spindle (6) by repeatedly clamping.

3. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 2, characterized in that: S300 also includes: measuring the radial runout of the hemispherical resonator at different positions by using a micrometer, and making the axis of the hemispherical resonator support rod coincide with the rotation axis of the workpiece spindle (3) by repeated clamping.

4. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 3, wherein: The key parts of the surface of the hemispherical resonator in S400 include: the inner rod end surface of the hemispherical resonator support rod, the inner rod side surface of the support rod, the outer rod side surface of the support rod, the inner spherical shell contour surface, the outer spherical shell contour surface, and the inner and outer fillets of the hemispherical shell.

5. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 4, characterized in that: S400 includes the following steps: The hemispherical resonator grinding machine is controlled to make the small diameter ball head grinding wheel approach the inner rod end face, the inner rod side face and the outer rod side face of the hemispherical resonator support rod to perform tool setting operation, the vibration signal of the support rod is collected by a laser Doppler vibrometer (1), and the coordinates of each tool setting position are determined according to the time when the vibration signal appears; the same operation is used to determine the two tool setting position coordinates of the inner spherical shell surface of the hemispherical resonator, the two tool setting position coordinates of the outer spherical shell surface and the tool setting position coordinates of the inner and outer fillets of the hemispherical shell.

6. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 5, characterized in that: S500 includes the following steps: S510, connecting the two tool setting positions on the inner spherical shell surface and the two tool setting positions on the outer spherical shell surface and drawing perpendicular midlines respectively, the intersection points of the two perpendicular midlines and the workpiece axis being the centers of the inner and outer spherical shell surfaces, respectively, and drawing the machining trajectories of the inner and outer spherical shell surfaces; S520, drawing a line parallel to the workpiece rotation axis through the tool position on the inner rod side to obtain a machining trajectory of the inner rod, and drawing a line parallel to the workpiece rotation axis through the tool position on the outer rod side to obtain a machining trajectory of the outer rod; S530: Draw an arc tangent to the inner rod machining trajectory and the inner spherical shell surface machining trajectory through the inner fillet tool setting position to obtain the inner fillet machining trajectory; draw an arc tangent to the outer rod machining trajectory and the outer spherical shell machining trajectory through the outer fillet tool setting position to obtain the outer fillet machining trajectory; S540, connecting each processing trajectory to obtain a small-diameter ball-end grinding wheel processing trajectory of the hemispherical resonator.

7. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 6, characterized in that: The specific frequencies mentioned in S600 include 5431 Hz and 7519 Hz.

8. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 7, characterized in that: The analysis of the hemispherical resonator grinding processing status described in S600 includes: judging the moment when the ball-end grinding wheel and the hemispherical resonator are completely ground based on whether a specific frequency appears; if an abnormal frequency different from the specific frequency appears during the processing, it indicates that the small-diameter ball-end grinding wheel is worn and needs to be stopped for processing.

9. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 8, characterized in that: The step of collecting the vibration signal of the hemispherical resonator during the grinding process by using the laser Doppler vibrometer (1) in S600 is specifically collecting the vibration signal of the lip edge position of the hemispherical resonator during the grinding process by using the laser Doppler vibrometer (1).

10. The method for optimizing the grinding process of a hemispherical resonator based on a laser Doppler vibrometer according to claim 9, characterized in that: The processing system comprises a hemispherical resonator grinding machine and a laser Doppler vibrometer (1), wherein the hemispherical resonator grinding machine comprises a machine bed, an X-axis linear motion platform (4), a Y-axis linear motion platform (5), a Z-axis linear motion platform (9), a C-axis turntable (8), a U-axis micro-displacement platform (7), a workpiece spindle (3), a grinding wheel spindle (6), a CCD camera (10), a triangular connecting frame, a fixed frame and a workbench; An X-axis linear motion platform (4), a Y-axis linear motion platform (5) and a Z-axis linear motion platform (9) are installed on the machine tool bed, wherein the X-axis linear motion platform (4) and the Y-axis linear motion platform (5) are installed in a cross-stacked manner, and the Z-axis linear motion platform (9) is installed perpendicular to the X-axis linear motion platform (4) and the Y-axis linear motion platform (5), and together they form a spatial rectangular coordinate system; The workbench is mounted on an X-axis linear motion platform (4) and a Y-axis linear motion platform (5); The workpiece spindle (3) is installed on the workbench, and the direction of the rotation axis is parallel to the Y axis; The CCD camera (10) is connected to the workbench via a micro-displacement module; The C-axis turntable (8) is mounted on the Z-axis linear motion platform (9) via a triangular connecting frame, and the rotation axis direction of the C-axis turntable (8) is parallel to the Z-axis; The U-axis micro-displacement platform (7) is installed on the C-axis turntable (8); The grinding wheel spindle (6) is mounted on a U-axis micro-displacement platform (7) via a fixed frame, wherein the angle between the grinding wheel spindle (6) and the U-axis micro-displacement platform (7) is 40°; The laser Doppler vibrometer (1) is mounted on a workbench via a support frame.

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