Measurement system and measurement method for identifying quality defects of hemispherical resonators

Abstract

The measuring system and method for identifying the quality defects of a hemispherical resonator solve the problem that it is difficult to identify the amplitude and orientation of the first three harmonics of the quality defects by measuring the vibration of the spherical shell of the resonator, and belong to the field of gyro measurement technology. The hemispherical resonator of the present invention is located on the posture adjustment mechanism, the Doppler laser vibrometer is aligned with the lip edge of the spherical shell, the four-partition piezoelectric ceramic is adjusted by the multi-dimensional fine-tuning mechanism, the ejector pin is pressed to the top of the support rod, the excitation system excites the resonator to the second-order resonance state, the Doppler laser vibrometer measures the vibration signal of the spherical shell to the vibrator controller, the vibrator controller controls the amplitude and phase of the excitation signal sent by the excitation system to ensure the amplitude stability of the hemispherical resonator, and at this time, the vibration signal measured by the four-partition piezoelectric ceramic tube is read; the posture adjustment mechanism rotates according to the set angle interval to obtain the amplitude information of the support rods at multiple positions, and the amplitude and orientation of the first three harmonics of the quality defects are identified.

Description

Technical Field

[0001] The invention relates to a measuring system for identifying quality defects of a hemispherical resonator, belonging to the technical field of gyro measurement. Background Art

[0002] The hemispherical resonant gyroscope is a new type of Columbia vibratory gyroscope, which has many advantages such as high precision, long life, high reliability, miniaturization and integration. It has broad application prospects in aerospace and other fields.

[0003] Among them, the hemispherical resonator is the core component of the gyroscope. The first three harmonics of the mass defect in the hemispherical resonator shell will cause the center of mass vibration, thereby generating energy dissipation, seriously affecting the quality factor of the resonator, and further affecting the output accuracy of the gyroscope. Therefore, it is necessary to perform mass balance on it, and the premise of mass balance is to identify the amplitude and orientation of the first three harmonics of the mass defect. At present, when the amplitude and orientation of the first three harmonics of the mass defect are identified, the vibration of the spherical shell is measured, such as the invention patent "A detection device and method for mass imbalance defects of a hemispherical resonator" with publication number CN 113686489 A. From an engineering perspective, because the resonant frequency of the spherical shell is about 5000Hz, the identification method requires the base to reach a linear vibration frequency of about 5000Hz to make the resonator vibrate. Such a high linear vibration frequency is difficult to achieve in engineering, so this solution is not reasonable and has limited actual engineering value. Summary of the invention

[0004] In view of the problem that it is difficult to identify the amplitude and orientation of the first three harmonics of quality defects by measuring the vibration of the spherical shell of the resonator, the present invention provides a measurement system and a measurement method for identifying the quality defects of a hemispherical resonator by measuring the vibration of the spherical shell support rod.

[0005] The present invention provides a measurement system for identifying quality defects of a hemispherical resonator, comprising a multi-dimensional fine-tuning mechanism 20, a four-partition piezoelectric ceramic tube, an ejector pin, a Doppler laser vibrometer, an excitation system, a vibrator controller and an industrial computer;

[0006] The multi-dimensional fine-tuning mechanism includes a Z-axis adjustment mechanism, an X-axis adjustment mechanism, a Y-axis adjustment mechanism, and a posture adjustment mechanism;

[0007] The hemispherical resonator is located on the posture adjustment mechanism, the industrial computer is connected to the posture adjustment mechanism, and the industrial computer controls the rotation angle of the posture adjustment mechanism;

[0008] The ejector pin is located above the hemispherical resonator and contacts the top of the hemispherical resonator support rod. The ejector pin is connected to the four-partition piezoelectric ceramic tube. The X-axis adjustment mechanism, the Y-axis adjustment mechanism and the Z-axis adjustment mechanism are used to adjust the X-axis, Y-axis and Z-axis positions of the four-partition piezoelectric ceramic tube respectively.

[0009] The laser emitted by the laser probe of the Doppler laser vibrometer is incident on the spherical shell of the hemispherical resonator to detect the vibration signal of the spherical shell of the hemispherical resonator; the Doppler laser vibrometer is connected to the vibrator controller to send the vibration signal of the spherical shell of the hemispherical resonator to the vibrator controller;

[0010] The excitation system sends an excitation signal to the spherical shell of the hemispherical resonator. The vibrator controller is connected to the excitation system and is used to control the amplitude and phase of the excitation signal sent by the excitation system according to the vibration signal of the spherical shell of the hemispherical resonator, so that the hemispherical resonator works in the second-order vibration mode.

[0011] The industrial computer is connected to the four-partition piezoelectric ceramic tube, and is used to collect the vibration signal of the hemispherical resonator support rod of the second-order vibration mode collected by the four-partition piezoelectric ceramic tube;

[0012] The industrial computer controls the rotation of the posture adjustment mechanism to obtain vibration signals of the hemispherical resonator support rod at multiple positions. After calculation, the amplitude and orientation of the first three harmonics of the hemispherical resonator for one-time identification of quality defects are obtained.

[0013] Preferably, the Z-axis adjustment mechanism includes an I-shaped block, a slide rail, a flange module, and a pressure rod;

[0014] The X-axis adjustment mechanism includes a support column and a connecting plate;

[0015] The Y-axis adjustment mechanism includes a base plate;

[0016] The bottom plate is provided with a U-shaped groove opening in the Y-axis direction;

[0017] The bottom end of the support column is fixed on the bottom plate, the bottom surface of the connecting plate is fixedly connected to the top end of the support column, and the top surface of the connecting plate is provided with a slide groove in the X-axis direction;

[0018] The bottom end of the I-shaped block is set in the slide groove of the connecting plate, and the side wall of the I-shaped block is provided with a slide rail in the z-axis direction. One end of the pressure rod is connected to the slide rail through a flange module.

[0019] The four-partition piezoelectric ceramic tube is arranged at the other end of the pressure rod.

[0020] Preferably, the multi-dimensional fine-tuning mechanism further comprises an actuator and a T-block; the bottom end of the inverted T-block is also arranged in the slide groove of the connecting plate;

[0021] The actuator is set on the pressure rod, and the probe of the actuator passes through the pressure rod and acts on the top of the inverted T-block; the industrial computer is connected to the actuator, and the height of the pressure rod is changed by adjusting the feed amount of the actuator probe, thereby adjusting the force exerted by the four-zone piezoelectric ceramic tube on the resonator.

[0022] Preferably, the Z-axis adjustment mechanism also includes a conductive base, which is fixed to the other end of the pressure rod, and the four-partition piezoelectric ceramic tube is placed in the groove of the conductive base. The central electrode of the four-partition piezoelectric ceramic tube is led out by conductive glue and connected to the conductive base.

[0023] Preferably, the Z-axis adjustment mechanism further includes a spring;

[0024] A spring is arranged on both sides of the pressure rod and the I-shaped block respectively, and the spring connects the pressure rod and the I-shaped block on the same side, and the spring is in a tension state.

[0025] Preferably, the excitation system includes interdigital electrodes and a high-voltage amplifier. The interdigital electrodes send excitation signals to the spherical shell of the hemispherical resonator. The interdigital electrodes are connected to the high-voltage amplifier. The high-voltage amplifier is connected to an industrial computer. The industrial computer changes the excitation force of the interdigital electrodes by adjusting the high-voltage amplifier.

[0026] Preferably, the posture adjustment mechanism comprises a clamping fixture, a turntable, a posture adjustment system and a motor driver;

[0027] The clamping tool is set on the turntable and is used to clamp the resonator. The output shaft of the posture adjustment system is connected to the turntable, the motor driver is connected to the posture adjustment system, and the industrial computer is connected to the motor driver. The industrial computer sends a driving signal to the motor driver, thereby controlling the rotation angle of the turntable.

[0028] The measuring method of the measuring system for identifying the quality defects of a hemispherical resonator of the present invention comprises:

[0029] S1. The hemispherical resonator is placed on the posture adjustment mechanism, the light spot of the Doppler laser vibrometer is aligned with the lip edge of the hemispherical resonator, and the center line of the excitation system is adjusted to coincide with the center line of the optical path of the Doppler laser vibrometer; the four-partition piezoelectric ceramic is adjusted by the multi-dimensional fine-tuning mechanism so that the ejector pin is pressed to the top of the support rod of the hemispherical resonator;

[0030] S2, the excitation system excites the resonator to the second-order resonance state, and the Doppler laser vibrometer transmits the measured vibration signal of the hemispherical resonator shell to the vibrator controller as a feedback signal. The vibrator controller controls the amplitude and phase of the excitation signal emitted by the excitation system according to the vibration signal of the hemispherical resonator shell to ensure the stability of the amplitude of the hemispherical resonator. At this time, the vibration signal of the hemispherical resonator support rod measured by the four-partition piezoelectric ceramic tube is read;

[0031] S3, the posture adjustment mechanism rotates according to the set angle interval, measures the vibration signal of the hemispherical resonator support rod according to S2, obtains the corresponding amplitude, and identifies the amplitude and orientation of the first three harmonics of the quality defect based on the amplitude information of the support rod at multiple positions measured.

[0032] Preferably, the industrial computer uses a least squares method to identify the amplitude and orientation of the first three harmonics of the hemispherical resonator quality defect:

[0033]

[0034] U(β) represents the amplitude of the vibration signal of the hemispherical resonator support rod, K1 and K2 represent the setting parameters, M1, M2, and M3 represent the amplitude parameters of the first three harmonics of the quality defect, respectively. They represent the rotation angle of the resonator respectively;

[0035] β1, β2, and β3 represent the azimuth parameters of the first three harmonics of the quality defect.

[0036] Preferably, in S3, the industrial computer controls the posture adjustment mechanism to realize continuous motion, fixed-length motion and zeroing motion, receives the angle value, velocity value and acceleration value of the posture adjustment mechanism in real time, and reduces the deviation by adjusting PID parameters, feedforward gain and differential compensation gain, thereby realizing closed-loop control.

[0037] The beneficial effects of the present invention are as follows: in the present invention, the spherical shell can quickly enter the resonant state under the electrode excitation condition. Through mechanical modeling analysis, it can be known that the unbalanced mass of the spherical shell will generate a force on the support rod, and the force will cause the forced vibration of the support rod. The present invention identifies the first three harmonics of the resonator mass defect by measuring the vibration. The principle is simple, the method is reliable, and it is easy to implement in engineering. The vibrator controller realizes stable amplitude output through amplitude and phase control, and can quantitatively analyze the residual unbalanced mass. The identification accuracy is high, which solves the problem of low efficiency of hemispherical resonant gyroscope performance test. The present invention designs a special multi-dimensional fine-tuning mechanism 20 for the leveling of the first three harmonics of the resonator mass defect. Only one sensor is used for all measurements. The excitation and measurement of the standing wave are carried out under the same conditions, and the overall structure can be fine-tuned on the XYZ axis to realize that the four-partition piezoelectric ceramic tube can accurately press the resonator for mass leveling. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the principle of the present invention;

[0039] Figure 2 It is a structural schematic diagram of the multi-dimensional fine-tuning mechanism 20 of the present invention;

[0040] Figure 3 A partial diagram of the multi-dimensional fine-tuning mechanism 20 of the present invention;

[0041] 1 represents a bottom plate, 2 represents a support column, 3 represents a connecting plate, 4 represents a spring, 5 represents an I-shaped block, 6 represents a slide rail, 7 represents a flange module, 8 represents an actuator, 9 represents a pressure rod, 10 represents a conductive base, 11 represents a four-partition piezoelectric ceramic tube, 12 represents a pin, 13 represents a hemispherical resonator, 14 represents a clamping fixture, 15 represents an interdigitated electrode, 16 represents a posture adjustment system, 17 represents a turntable, 18 represents a T-block, 19 represents a vacuum box, 20 represents a multi-dimensional fine-tuning mechanism 20, 21 represents a posture adjustment mechanism 21, 22 represents a multi-dimensional platform, 23 represents a Doppler laser vibrometer, 24 represents a signal conditioning box No. 1, 25 represents a high-voltage amplifier, 26 represents a signal conditioning box No. 2, 27 represents a vibrator controller, 28 represents a motor driver, 29 represents a No. 1 through-bin flange, 30 represents a No. 2 through-bin flange, and 31 represents a vibration isolation platform. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0045] A measurement system for identifying quality defects of a hemispherical resonator according to this embodiment, such as Figure 1 As shown, it includes a multi-dimensional fine-tuning mechanism 20, a four-partition piezoelectric ceramic tube 11, a pin 12, a Doppler laser vibrometer 23, an excitation system, a vibrator controller 27 and an industrial computer;

[0046] The multi-dimensional fine-tuning mechanism 20 includes a Z-axis adjustment mechanism, an X-axis adjustment mechanism, a Y-axis adjustment mechanism, and a posture adjustment mechanism 21;

[0047] The hemispherical resonator 13 is located on the posture adjustment mechanism, the industrial control computer is connected to the posture adjustment mechanism, and the industrial control computer controls the rotation angle of the posture adjustment mechanism;

[0048] The ejector pin 12 is located above the hemispherical resonator 13 and contacts the top of the support rod of the hemispherical resonator 13. The ejector pin 12 is connected to the four-partition piezoelectric ceramic tube 11. The X-axis adjustment mechanism, the Y-axis adjustment mechanism and the Z-axis adjustment mechanism are used to adjust the X-axis, Y-axis and Z-axis positions of the four-partition piezoelectric ceramic tube 11 respectively.

[0049] The laser emitted by the laser probe of the Doppler laser vibrometer 23 is incident on the spherical shell of the hemispherical resonator 13, so as to detect the vibration signal of the spherical shell of the hemispherical resonator 13; the Doppler laser vibrometer 23 is connected to the vibrator controller 27, and sends the vibration signal of the spherical shell of the hemispherical resonator 13 to the vibrator controller 27;

[0050] The excitation system sends an excitation signal to the spherical shell of the hemispherical resonator 13, and the vibrator controller 27 is connected to the excitation system and is used to control the amplitude and phase of the excitation signal sent by the excitation system according to the vibration signal of the spherical shell of the hemispherical resonator 13, so that the hemispherical resonator 13 works in the second-order vibration mode;

[0051] The industrial computer is connected to the four-partition piezoelectric ceramic tube 11, and is used to collect the vibration signal of the hemispherical resonator 13 support rod of the second-order vibration mode of the four-partition piezoelectric ceramic tube 11;

[0052] The industrial computer controls the rotation of the posture adjustment mechanism to obtain vibration signals of the support rods of the hemispherical resonator 13 at multiple positions, and calculates the amplitude and orientation of the first three harmonics of the hemispherical resonator 13 for one-time identification of quality defects.

[0053] The measurement system of this embodiment transmits a trigger signal to the vibrator controller 27 through the industrial computer to put it in working state. The Doppler laser vibrometer 23 detects the vibration rate signal of the spherical shell of the resonator, and the measurement signal is transmitted to the vibrator controller 27. The vibrator controller 27 controls the amplitude of the output voltage according to the size of the obtained measurement signal. The voltage signal is transmitted to the spherical shell of the hemispherical resonator 13 through the excitation system, thereby realizing the frequency tracking and amplitude control of the hemispherical resonator 13. The multi-dimensional fine-tuning mechanism 20 presses the probe pressed by the four-partition piezoelectric ceramic tube 11 on the upper end of the support rod of the hemispherical resonator 13. The vibration amplitude of the support rod of the hemispherical resonator 13 will be characterized by the charge signal output by the four-partition piezoelectric ceramic tube 11, thereby realizing the identification of the amplitude and orientation of the first three harmonics of the resonator quality defect.

[0054] In a preferred embodiment, Figure 2 As shown, the Z-axis adjustment mechanism of this embodiment includes an I-shaped block 5, a slide rail 6, a flange module 7, and a pressure rod 9; the X-axis adjustment mechanism includes a support column 2 and a connecting plate 3;

[0055] The Y-axis adjustment mechanism includes a bottom plate 1, on which a U-shaped groove opening in the Y-axis direction is provided, and the U-shaped groove on the bottom plate 1 ensures that the overall structure can be adjusted on the Y-axis;

[0056] The bottom end of the support column 2 is fixed on the bottom plate 1, the bottom surface of the connecting plate 3 is fixedly connected to the top end of the support column 2, and the top surface of the connecting plate 3 is provided with a slide groove in the X-axis direction;

[0057] The bottom end of the I-shaped block 5 is arranged in the slide groove of the connecting plate 3. The connecting plate 3 with the slide groove can ensure that the I-shaped block 5 and the T-shaped block 18 can be adjusted as a whole on the X-axis. A slide rail 6 in the z-axis direction is arranged on the side wall of the I-shaped block 5. One end of the pressure rod 9 is connected to the slide rail 6 through the flange module 7, which can ensure that the overall structure can be adjusted on the Z-axis. The four-partition piezoelectric ceramic tube 11 is arranged at the other end of the pressure rod 9.

[0058] In a preferred embodiment, Figure 2 and Figure 3 As shown, the multi-dimensional fine-tuning mechanism 20 of this embodiment further includes an actuator 8 and a T-block 18; the bottom end of the inverted T-block 18 is also disposed in the slide groove of the connecting plate 3;

[0059] The actuator 8 is arranged on the pressure rod 9, and the probe of the actuator 8 passes through the pressure rod 9 and acts on the top of the inverted T-block 18; the industrial computer is connected to the actuator 8, and the height of the pressure rod 9 is changed by adjusting the feed amount of the probe of the actuator 8, thereby adjusting the force exerted by the pressure four-partition piezoelectric ceramic tube 11 on the resonator.

[0060] The probe of the actuator 8 is applied to the T-block 18, and the height of the pressure rod 9 is changed by adjusting the feed amount of the actuator 8, thereby adjusting the force exerted by the four-partition piezoelectric ceramic tube 11 on the hemispherical resonator 13, so as to avoid excessive pressure that suppresses the vibration output of the support rod of the hemispherical resonator 13, thereby failing to effectively identify the defective mass distribution of the hemispherical resonator 13. After the height adjustment of the actuator 8 is completed, a locking operation needs to be performed to ensure that the pressure of the four-partition piezoelectric ceramic tube 11 on the hemispherical resonator 13 is always consistent, and to ensure the consistency and repeatability of the vibration amplitude of the support rod.

[0061] Working principle of the four-partition piezoelectric ceramic tube 11: The piezoelectric ceramic tube scanner is a radially polarized piezoelectric ceramic, with one electrode inside and four outside. When a positive voltage is applied to a certain area on the outside, the area shrinks axially, and a negative voltage is applied to the other side, the area stretches, and the piezoelectric ceramic tube will produce a translational motion. When all four external partitions are loaded with positive voltage, the piezoelectric ceramic tube shrinks axially, and when the internal part is loaded with a full-amplitude negative voltage, the piezoelectric ceramic tube shrinks to the maximum displacement.

[0062] In a preferred embodiment, the Z-axis adjustment mechanism also includes a conductive base 10, which is fixed to the other end of the pressure rod 9. The four-partition piezoelectric ceramic tube 11 is placed in the groove of the conductive base 10. The center electrode of the four-partition piezoelectric ceramic tube 11 is led out by conductive glue and connected to the conductive base 10, thereby leading out the center electrode. This method will not damage the components in the four-partition piezoelectric ceramic tube 11.

[0063] In a preferred embodiment, the Z-axis adjustment mechanism of this embodiment further includes a spring 4;

[0064] A spring 4 is arranged on both sides of the pressure rod 9 and the I-shaped block 5. The spring 4 connects the pressure rod 9 and the I-shaped block 5 on the same side. The spring 4 is in a stretched state. The spring 4 realizes a clamping effect to avoid a gap between the slide rail 6 and the flange module 7, which causes a measurement error in the vibration test of the support rod of the hemispherical resonator 13.

[0065] In a preferred embodiment, the excitation system of this embodiment includes a forked electrode 15 and a high-voltage amplifier 25. The forked electrode 15 sends an excitation signal to the spherical shell of the hemispherical resonator 13. The forked electrode 15 is connected to the high-voltage amplifier 25. The high-voltage amplifier 25 is connected to an industrial computer. The industrial computer changes the excitation force of the forked electrode 15 by adjusting the high-voltage amplifier 25.

[0066] In the preferred embodiment, the posture adjustment mechanism of this embodiment includes a clamping tool 14, a turntable 17, a posture adjustment system 16 and a motor driver 28;

[0067] The clamping fixture 14 is arranged on the turntable 17 and is used to clamp the resonator. The output shaft of the posture adjustment system 16 is connected to the turntable 17, the motor driver 28 is connected to the posture adjustment system 16, the industrial computer is connected to the motor driver 28, and the industrial computer sends a driving signal to the motor driver 28, thereby controlling the rotation angle of the turntable 17. The ejector pin 12 can be pressed on different positions of the hemispherical resonator 13 through the turntable 17, thereby improving the recognition accuracy of the first three times of the quality defect resonator.

[0068] The multi-dimensional fine-tuning mechanism 20 of this embodiment is placed in the vacuum box 19, and the signal lines entering and exiting the vacuum box 19 are connected through the No. 1 through-bin flange 29 and the No. 2 through-bin flange 30. The measurement signal of the four-zone piezoelectric ceramic tube is input to the industrial computer after being conditioned by the No. 1 signal conditioning box, and the measurement signal obtained by the Doppler laser vibrometer 23 is input to the industrial computer after being conditioned by the No. 2 signal conditioning box 26; the Doppler laser vibrometer 23 of this embodiment is placed on the multi-dimensional platform 22 for adjusting the angle and position of the Doppler laser vibrometer 23, and the multi-dimensional fine-tuning mechanism 20 and the Doppler laser vibrometer 23 of this embodiment are placed on the vibration isolation platform 31.

[0069] The measuring method of the measuring system in this embodiment includes:

[0070] Step 1, the hemispherical resonator 13 is located on the posture adjustment mechanism: the clamping fixture 14 is fixed on the turntable 17 and the rotation axis of the clamping fixture 14 is ensured to coincide with the rotation axis of the turntable 17, and then the vibrator is fixed on the clamping fixture 14, the light spot of the Doppler laser vibrometer 23 is aligned with the lip edge of the hemispherical resonator 13, and the center line of the excitation system is adjusted to coincide with the center line of the optical path of the Doppler laser vibrometer 23; the four-partition piezoelectric ceramic is adjusted by the multi-dimensional fine-tuning mechanism 20, so that the ejector pin 12 is pressed to the top of the support rod of the hemispherical resonator 13;

[0071] Step 2, the interdigitated electrode 15 excites the resonator to a second-order resonance state, and the Doppler laser vibrometer 23 transmits the measured vibration signal of the spherical shell of the hemispherical resonator 13 as a feedback signal to the vibrator controller 27. The vibrator controller 27 controls the amplitude and phase of the excitation signal emitted by the excitation system according to the vibration signal of the spherical shell of the hemispherical resonator 13 to ensure the stability of the amplitude of the hemispherical resonator 13. At this time, the vibration signal of the support rod of the hemispherical resonator 13 measured by the four-partition piezoelectric ceramic tube 11 is read, and the vibration signal is output in the form of voltage.

[0072] Step 3, the posture adjustment mechanism rotates according to the set angle interval, and the vibration signal of the support rod of the hemispherical resonator 13 is measured according to step 2 to obtain the corresponding amplitude. A total of 18 amplitude information of the support rod are collected, and the amplitude and orientation of the first three harmonics of the quality defect are identified based on the amplitude information of the support rod at the 18 positions measured.

[0073] In the preferred embodiment, the industrial computer of this embodiment uses the least square method to identify the amplitude and orientation of the first three harmonics of the quality defect of the hemispherical resonator 13:

[0074] This application measures the vibration of the bracket of the unbalanced resonator. The resonator that has eliminated frequency cracking is elastically fixed to one end of the support column 2. The other end is connected to the four-partition piezoelectric ceramic tube 11. The amplitude (U) of the signal of the four-partition piezoelectric ceramic tube 11 is proportional to the amplitude of the bracket. The sensor has a circular sensitivity diagram in the XOZ plane. When the standing wave is excited along the X direction, there is

[0075] U=K1(3M1 cosβ1+M3 cos3β1)+K2M2 cos2β2

[0076] The coefficients K1 and K2 can be determined experimentally. Figure 3 If the rotation direction in the above formula rotates the resonator by a certain angle β, then all the angle values ​​in the above formula will also change the rotation angle. Therefore, when the standing wave is excited along the X direction, we have

[0077]

[0078] U(β) represents the amplitude of the vibration signal of the support rod of the hemispherical resonator 13, K1 and K2 represent the setting parameters, M1, M2, and M3 represent the amplitude parameters of the first three harmonics of the quality defect, respectively. They represent the rotation angle of the resonator respectively; β1, β2, β3 represent the azimuth parameters of the first three harmonics of the mass defect respectively.

[0079] The above shows the dependence of the signal amplitude of the four-part piezoelectric ceramic tube 11 on the rotation angle φ of the resonator. When the hemispherical resonator 13 is rotated around its symmetry axis by Δφ steps, the voltage of the four-part piezoelectric ceramic tube 11 is measured, and the relationship U(φ) can be obtained.

[0080] In a preferred embodiment, in step 3 of this implementation method, the industrial computer controls the posture adjustment mechanism 21 to realize continuous motion, fixed-length motion and zeroing motion, receives the angle value, velocity value and acceleration value of the posture adjustment mechanism 21 in real time, and reduces the deviation by adjusting PID parameters, feedforward gain and differential compensation gain, thereby realizing closed-loop control.

[0081] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A measurement system for identifying quality defects of a hemispherical resonator, characterized in that: The system includes a multi-dimensional fine-tuning mechanism, a four-partition piezoelectric ceramic tube, an ejector pin, a Doppler laser vibrometer, an excitation system, a vibrator controller and an industrial computer; The multi-dimensional fine-tuning mechanism includes a Z-axis adjustment mechanism, an X-axis adjustment mechanism, a Y-axis adjustment mechanism, and a posture adjustment mechanism; The hemispherical resonator is located on the posture adjustment mechanism, the industrial computer is connected to the posture adjustment mechanism, and the industrial computer controls the rotation angle of the posture adjustment mechanism; The ejector pin is located above the hemispherical resonator and contacts the top of the hemispherical resonator support rod. The ejector pin is connected to the four-partition piezoelectric ceramic tube. The X-axis adjustment mechanism, the Y-axis adjustment mechanism and the Z-axis adjustment mechanism are used to adjust the X-axis, Y-axis and Z-axis positions of the four-partition piezoelectric ceramic tube respectively. The laser emitted by the laser probe of the Doppler laser vibrometer is incident on the spherical shell of the hemispherical resonator to detect the vibration signal of the spherical shell of the hemispherical resonator; the Doppler laser vibrometer is connected to the vibrator controller to send the vibration signal of the spherical shell of the hemispherical resonator to the vibrator controller; The excitation system sends an excitation signal to the spherical shell of the hemispherical resonator. The vibrator controller is connected to the excitation system and is used to control the amplitude and phase of the excitation signal sent by the excitation system according to the vibration signal of the spherical shell of the hemispherical resonator, so that the hemispherical resonator works in the second-order vibration mode. The industrial computer is connected to the four-partition piezoelectric ceramic tube, and is used to collect the vibration signal of the hemispherical resonator support rod of the second-order vibration mode collected by the four-partition piezoelectric ceramic tube; The industrial computer controls the rotation of the posture adjustment mechanism to obtain vibration signals of the hemispherical resonator support rod at multiple positions. After calculation, the amplitude and orientation of the first three harmonics of the hemispherical resonator for one-time identification of quality defects are obtained.

2. The measurement system for identifying quality defects of a hemispherical resonator according to claim 1, characterized in that: The Z-axis adjustment mechanism includes an I-block, a slide rail, a flange module, and a pressure rod; The X-axis adjustment mechanism includes a support column and a connecting plate; The Y-axis adjustment mechanism includes a base plate; The bottom plate is provided with a U-shaped groove opening in the Y-axis direction; The bottom end of the support column is fixed on the bottom plate, the bottom surface of the connecting plate is fixedly connected to the top end of the support column, and the top surface of the connecting plate is provided with a slide groove in the X-axis direction; The bottom end of the I-shaped block is set in the slide groove of the connecting plate, and the side wall of the I-shaped block is provided with a slide rail in the z-axis direction. One end of the pressure rod is connected to the slide rail through a flange module. The four-partition piezoelectric ceramic tube is arranged at the other end of the pressure rod.

3. The measurement system for identifying quality defects of a hemispherical resonator according to claim 2, characterized in that: The multi-dimensional fine-tuning mechanism also includes an actuator and a T-block; the bottom end of the inverted T-block is also arranged in the slide groove of the connecting plate; The actuator is set on the pressure rod, and the probe of the actuator passes through the pressure rod and acts on the top of the inverted T-block; the industrial computer is connected to the actuator, and the height of the pressure rod is changed by adjusting the feed amount of the actuator probe, thereby adjusting the force exerted by the four-zone piezoelectric ceramic tube on the resonator.

4. The measurement system for identifying quality defects of a hemispherical resonator according to claim 2, characterized in that: The Z-axis adjustment mechanism also includes a conductive base, which is fixed to the other end of the pressure rod. The four-partition piezoelectric ceramic tube is placed in the groove of the conductive base. The central electrode of the four-partition piezoelectric ceramic tube is led out by conductive glue and connected to the conductive base.

5. The measurement system for identifying quality defects of a hemispherical resonator according to claim 2, characterized in that: The Z-axis adjustment mechanism also includes a spring; A spring is arranged on both sides of the pressure rod and the I-shaped block respectively, and the spring connects the pressure rod and the I-shaped block on the same side, and the spring is in a tension state.

6. The measurement system for identifying quality defects of a hemispherical resonator according to claim 1, characterized in that: The excitation system includes interdigital electrodes and a high-voltage amplifier. The interdigital electrodes send excitation signals to the spherical shell of the hemispherical resonator. The interdigital electrodes are connected to the high-voltage amplifier, which is connected to an industrial computer. The industrial computer changes the excitation force of the interdigital electrodes by adjusting the high-voltage amplifier.

7. The measurement system for identifying quality defects of a hemispherical resonator according to claim 1, characterized in that: The posture adjustment mechanism includes a clamping fixture, a turntable, a posture adjustment system and a motor driver; The clamping tool is set on the turntable and is used to clamp the resonator. The output shaft of the posture adjustment system is connected to the turntable, the motor driver is connected to the posture adjustment system, and the industrial computer is connected to the motor driver. The industrial computer sends a driving signal to the motor driver, thereby controlling the rotation angle of the turntable.

8. The measuring method of the measuring system for identifying quality defects of a hemispherical resonator according to claim 1, characterized in that: The method comprises: S1. The hemispherical resonator is placed on the posture adjustment mechanism, the light spot of the Doppler laser vibrometer is aligned with the lip edge of the hemispherical resonator, and the center line of the excitation system is adjusted to coincide with the center line of the optical path of the Doppler laser vibrometer; the four-partition piezoelectric ceramic is adjusted by the multi-dimensional fine-tuning mechanism so that the ejector pin is pressed to the top of the support rod of the hemispherical resonator; S2, the excitation system excites the resonator to the second-order resonance state, and the Doppler laser vibrometer transmits the measured vibration signal of the hemispherical resonator shell to the vibrator controller as a feedback signal. The vibrator controller controls the amplitude and phase of the excitation signal emitted by the excitation system according to the vibration signal of the hemispherical resonator shell to ensure the stability of the amplitude of the hemispherical resonator. At this time, the vibration signal of the hemispherical resonator support rod measured by the four-partition piezoelectric ceramic tube is read; S3, the posture adjustment mechanism rotates according to the set angle interval, measures the vibration signal of the hemispherical resonator support rod according to S2, obtains the corresponding amplitude, and identifies the amplitude and orientation of the first three harmonics of the quality defect based on the amplitude information of the support rod at multiple positions measured.

9. The measuring method according to claim 8, characterized in that: The industrial computer uses the least square method to identify the amplitude and orientation of the first three harmonics of the hemispherical resonator quality defect: U(β) represents the amplitude of the vibration signal of the hemispherical resonator support rod, K1 and K2 represent the setting parameters, M1, M2, and M3 represent the amplitude parameters of the first three harmonics of the quality defect, respectively. They represent the rotation angle of the resonator respectively; β1, β2, and β3 represent the azimuth parameters of the first three harmonics of the quality defect.

10. The measuring method according to claim 8, characterized in that: In S3, the industrial computer controls the posture adjustment mechanism to achieve continuous motion, fixed-length motion and zeroing motion, receives the angle value, velocity value and acceleration value of the posture adjustment mechanism in real time, and reduces the deviation by adjusting PID parameters, feedforward gain and differential compensation gain, thereby achieving closed-loop control.

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