A hemispherical resonator batch testing system and testing method

Abstract

A batch testing system and method for hemispherical resonators, which belongs to the field of inertial technology. The present invention solves the problems of low testing accuracy and testing efficiency of existing testing methods. The present invention fixes the hemispherical resonators to be tested on the upper surface of a rotating platform through a resonator clamp in turn, controls the rotation of the vacuum turntable through a turntable controller, and drives the rotating platform to rotate the hemispherical resonator to be tested to the position to be tested. After the laser vibrometer is turned on, the focal length of the laser is adjusted so that the focus is located at the lip edge of the hemispherical resonator; the piezoelectric exciter is started to excite the hemispherical resonator to be tested, and the vibration signal of the hemispherical resonator to be tested is obtained by using the laser vibrometer; the obtained vibration signal is processed to obtain the resonant frequency, quality factor, frequency splitting and inherent rigid axis orientation parameters of the hemispherical resonator to be tested; until all the hemispherical resonators to be tested on the rotating platform are tested. The method of the present invention can be applied to the testing of hemispherical resonators.

Description

Technical Field

[0001] The invention belongs to the field of inertial technology, and in particular relates to a hemispherical resonator batch testing system and a testing method. Background Art

[0002] The hemispherical resonant gyroscope is a new type of Coriolis gyroscope. Its working principle is that the vibrating standing wave precesses under the action of the Coriolis force, and the angular velocity of the standing wave precession is proportional to the external input angular velocity. The hemispherical resonant gyroscope has the advantages of simple structure, high measurement accuracy, long working life, radiation resistance and short-term power failure, and has broad application prospects in aerospace and other fields.

[0003] The hemispherical resonator is the core component of the hemispherical resonator gyroscope. It is made of high-purity fused quartz. In order to ensure that the hemispherical resonator has good vibration performance, ultra-precision grinding technology is required to ensure the high shape and position accuracy of the hemispherical resonator. After machining, chemical etching is required to eliminate the mechanical damage on the surface of the resonator to improve the quality factor, and combined with ion beam leveling technology, the circumferential error of the machining is adjusted to reduce its frequency cracking. In addition, in order to realize the excitation and detection of the vibration mode of the resonator, metallization coating is required on its inner surface. All of the above processes will involve the testing of vibration parameters such as the quality factor, resonant frequency, inherent rigid axis azimuth and frequency cracking of the hemispherical resonator. The vibration performance parameters of the resonator need to be tested in each of the above process links, but the test accuracy of the existing test methods is still low, and the existing test methods cannot achieve rapid batch testing.

[0004] Therefore, in order to improve the test efficiency and accuracy of the vibration performance parameters of the hemispherical resonator and meet the subsequent mass and standardized production needs, a batch testing method for the hemispherical resonator must be proposed to achieve rapid and accurate detection of the vibration performance parameters of the hemispherical resonator. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of low test accuracy and test efficiency of the existing test methods, and to propose a hemispherical resonator batch test system and test method.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] According to one aspect of the present invention, a hemispherical resonator batch testing system comprises a rotating platform, a resonator fixture, a vacuum box, a hemispherical resonator, a piezoelectric vibrator, a glass flange, a vacuum turntable and a laser vibrometer, wherein:

[0008] The rotating platform, the resonator fixture, the hemispherical resonator, the piezoelectric exciter and the vacuum turntable are arranged inside the vacuum box;

[0009] The rotating platform is a circular turntable, and a plurality of resonator fixtures are evenly arranged along the circumferential direction on the upper surface of the rotating platform;

[0010] The resonator fixture is used to fix the hemispherical resonator on the rotating platform;

[0011] The rotating platform is fixedly arranged on a vacuum turntable, and the vacuum turntable is used to drive the rotating platform to rotate to realize the switching of different hemispherical resonators;

[0012] The piezoelectric exciter is arranged on the side of the rotating platform, and the piezoelectric exciter is used to excite the hemispherical resonator;

[0013] The laser vibrometer is arranged outside the vacuum box, and the measuring light path of the laser vibrometer is focused on the lip edge position of the hemispherical resonator through the glass flange arranged on the vacuum box.

[0014] Furthermore, the system also includes a turntable controller, a laser vibrometer controller and a host computer. The vacuum turntable is controlled by the turntable controller, the laser vibrometer is controlled by the laser vibrometer controller, the turntable controller communicates with the host computer through the serial port, and the laser vibrometer controller communicates with the host computer through the network port.

[0015] Furthermore, the system also includes an electromagnetic limit pin, which is arranged inside the vacuum box and below the rotating platform, and is used to limit the free rotation of the rotating platform after being controlled by the network controller.

[0016] Furthermore, the system also includes a grating and a grating reading head, which are arranged inside the vacuum box and fixed on the vacuum turntable, and are used to provide real-time feedback of the rotation angle of the rotating platform to the turntable controller.

[0017] Furthermore, the vacuum box and the laser vibrometer are arranged on an air-floating shock-absorbing platform.

[0018] According to another aspect of the present invention, a method for batch testing of hemispherical resonators is provided, the method specifically comprising the following steps:

[0019] Step 1: Fix the hemispherical resonator to be tested on the upper surface of the rotating platform through the resonator fixture, then close the vacuum box and start vacuuming;

[0020] Step 2: The host computer sends a command to the electromagnetic limit pin through the network controller to enable it, and controls the vacuum turntable to rotate through the turntable controller. After the vacuum turntable drives the rotating platform to rotate the hemispherical resonator to be measured to the position to be measured, the electromagnetic limit pin is released to limit the circumferential rotation of the rotating platform;

[0021] Step 3: Turn on the laser vibrometer and adjust the focal length of the laser so that the focus is located at the lip edge of the hemispherical resonator;

[0022] Step 4: when the vacuum degree of the vacuum box is less than P, the piezoelectric exciter is started to excite the hemispherical resonator to be tested, and the vibration signal of the hemispherical resonator to be tested is obtained by using a laser vibrometer;

[0023] Step 5, processing the vibration signal obtained in step 4 to obtain the resonant frequency, quality factor, frequency decomposition and inherent rigid axis orientation parameters of the hemispherical resonator to be measured;

[0024] Step 6: Repeat the process from step 2 to step 5 until all the hemispherical resonators to be tested on the rotating platform have completed the test.

[0025] Furthermore, the value of P is 1×10 -3 Pa.

[0026] Furthermore, the specific process of step 5 is as follows:

[0027] Fit the vibration signal obtained in step 4:

[0028] w(θ,t)=[(Acos2θ ω cosωt+Asin2θ ω cos(ω+Δω)t]e -t / τ

[0029] Among them, w(θ,t) is the fitting signal, t is time, ω is the resonant frequency, τ is the time constant, Δω is the frequency decomposition, θ ω is the azimuth of the inherent rigid axis, A is the vibration amplitude at the lip edge of the hemispherical resonator, and e is the base of the natural logarithm;

[0030] By extracting the envelope information of the fitting signal, the resonant frequency, quality factor, frequency splitting and inherent rigid axis azimuth parameters of the hemispherical resonator are obtained.

[0031] The beneficial effects of the present invention are:

[0032] 1. The present invention uses a laser vibrometer to achieve contactless batch testing of the vibration performance of a hemispherical resonator, and can achieve high-precision testing of the vibration performance of a hemispherical resonator;

[0033] 2. The present invention designs a specific disc-type work surface, which can realize the vibration performance parameter test of up to 16 hemispherical resonators in one batch, greatly improving the test efficiency;

[0034] 3. The present invention integrates the turntable control and the electromagnetic limit pin control by writing control software, and communicates through the network port or the serial port, which greatly reduces the complexity of the system operation and meets the requirements of batch testing;

[0035] 4. The present invention eliminates the influence of the mechanical jitter of the turntable in the traditional test system on the vibration parameter test of the resonator through the electromagnetic limit pin, and realizes the vibration signal detection with high signal-to-noise ratio;

[0036] 5. The present invention uses a piezoelectric exciter with extremely fast response speed to simulate the impulse response to excite the hemispherical resonator, which can excite various vibration modes of the resonator. By using the modal attenuation characteristics of the vibrator itself, the hemispherical resonator whose main vibration mode is non-second-order bending vibration is screened out, providing a primary screening mechanism, thereby improving the test efficiency of the hemispherical resonator. In addition, the impulse response can ensure that the two second-order bending modes of the resonator obtain consistent energy, thereby solving the problem of complex and inaccurate testing of the inherent rigid shaft angle using electrode excitation, and providing a reference for the subsequent quality leveling process;

[0037] 6. The present invention designs a unique hemispherical resonator vibration parameter testing algorithm, which can realize the testing of parameters such as frequency decomposition, quality factor and inherent rigidity axis angle through only one measurement, and has high testing accuracy and testing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of the method of the present invention;

[0039] Figure 2 is a system structure diagram of the present invention;

[0040] In the figure: 1, electromagnetic limit pin; 2, rotating platform; 3, resonator fixture; 4, vacuum box; 5, hemispherical resonator; 6, piezoelectric exciter; 7, glass flange; 8, vacuum turntable; 9, grating; 10, grating reading head; 11, laser vibrometer;

[0041] Figure 3 It is the control software function diagram of the present invention;

[0042] Figure 4 This is a test effect diagram. DETAILED DESCRIPTION

[0043] Specific implementation method 1. Combination Figure 2 The present embodiment is described as a hemispherical resonator batch testing system, the system comprising a rotating platform 2, a resonator fixture 3, a vacuum box 4, a hemispherical resonator 5, a piezoelectric exciter 6, a glass flange 7, a vacuum turntable 8 and a laser vibrometer 11, wherein:

[0044] The rotating platform 2, the resonator fixture 3, the hemispherical resonator 5, the piezoelectric exciter 6 and the vacuum turntable 8 are arranged inside the vacuum box 4;

[0045] The rotating platform 2 is a circular turntable, and a plurality of resonator fixtures 3 are evenly arranged along the circumferential direction on the upper surface of the rotating platform 2;

[0046] The resonator fixture 3 is used to fix the hemispherical resonator 5 on the rotating platform 2;

[0047] The rotating platform 2 is fixedly arranged on the vacuum turntable 8, and the rotating platform 2 and the vacuum turntable 8 are arranged coaxially, and the vacuum turntable 8 is used to drive the rotating platform 2 to rotate to realize the switching of different hemispherical resonators 5;

[0048] The piezoelectric exciter 6 is arranged on the side of the rotating platform 2, and the piezoelectric exciter 6 is used to excite the hemispherical resonator 5;

[0049] The laser vibrometer 11 is disposed outside the vacuum box 4 , and the measuring light path of the laser vibrometer 11 is focused on the lip edge of the hemispherical resonator 5 through the glass flange 7 disposed on the vacuum box 4 .

[0050] The hemispherical resonator 5 is fixed on the rotating platform 2 by the resonator fixture 3, and the vacuum turntable 8 is rotated to realize the switching of different hemispherical resonators. The laser vibrometer 11 is placed outside the vacuum box, and the measuring light path is focused on the lip edge of the hemispherical resonator through the glass flange 7. The vacuum turntable 8 feeds back the rotation angle of the rotating platform in real time through the grating 9 and the grating reading head 10 to realize the high-precision closed-loop control of the rotating platform. The electromagnetic limit pin 1 is used to limit the circumferential free rotation of the rotating platform. The electromagnetic limit pin 1 and the piezoelectric exciter 6 are controlled by the network controller, and the automatic control can be realized by sending instructions through the host computer.

[0051] Specific embodiment 2: This embodiment is different from specific embodiment 1 in that the system also includes a turntable controller, a laser vibrometer controller and a host computer. The vacuum turntable 8 is controlled by the turntable controller, the laser vibrometer 11 is controlled by the laser vibrometer controller, the turntable controller communicates with the host computer through the serial port, and the laser vibrometer controller communicates with the host computer through the network port.

[0052] The turntable controller includes three modes: continuous motion, fixed-length motion and return-to-zero motion. The rotation angle of the rotating platform is used as the controlled object, the high-precision stepper motor is used as the actuator, and the grating and grating reading head are used as feedback mechanisms to provide real-time feedback of angle value, velocity value and acceleration value, and reduce the deviation by adjusting PID parameters, feedforward gain and differential compensation gain, thereby achieving closed-loop control.

[0053] The other steps and parameters are the same as those in the first embodiment.

[0054] Specific implementation method three: This implementation method is different from specific implementation methods one or two in that the system also includes an electromagnetic limit pin 1, which is arranged inside the vacuum box 4 and below the rotating platform 2, and is used to limit the free rotation of the rotating platform 2 after being controlled by a network controller.

[0055] In this embodiment, the electromagnetic limit pin 1 is used to limit the free rotation of the rotating platform to prevent the rotating platform from having unexpected rotation during the hemispherical resonator test, thereby affecting the test results. The electromagnetic limit pin 1 is controlled by a network controller.

[0056] The other steps and parameters are the same as those in the first or second embodiment.

[0057] Specific embodiment four: This embodiment is different from any one of specific embodiments one to three in that the system also includes a grating 9 and a grating reading head 10, and the grating 9 and the grating reading head 10 are arranged inside the vacuum box 4 and fixed on the vacuum turntable 8, and are used to provide real-time feedback of the rotation angle of the rotating platform 2 to the turntable controller.

[0058] In this embodiment, the rotation angle of the rotating platform is fed back in real time through the grating 9 and the grating reading head 10, and high-precision closed-loop control of the rotating platform is achieved through the turntable controller.

[0059] The other steps and parameters are the same as those in Specific Embodiments 1 to 3.

[0060] Specific implementation mode 5: This implementation mode is different from any one of specific implementation modes 1 to 4 in that the vacuum box 4 and the laser vibrometer 11 are arranged on an air-floating shock-absorbing platform.

[0061] The other steps and parameters are the same as those in Specific Embodiments 1 to 4.

[0062] Specific implementation method VI. Combination Figure 1 The present embodiment describes a method for batch testing of hemispherical resonators, the method specifically comprising the following steps:

[0063] Step 1, fix the hemispherical resonator 5 to be tested on the upper surface of the rotating platform 2 through the resonator fixture 3 in turn, then close the vacuum box 4 and start vacuuming;

[0064] Step 2, the host computer sends a command to the electromagnetic limit pin 1 through the network controller to enable, and controls the vacuum turntable 8 to rotate through the turntable controller. After the vacuum turntable 8 drives the rotating platform 2 to rotate so that the hemispherical resonator to be measured rotates to the position to be measured, the electromagnetic limit pin 1 is released to limit the circumferential rotation of the rotating platform 2;

[0065] Step 3, after turning on the laser vibrometer 11, adjust the focal length of the laser so that the focus is located at the lip edge of the hemispherical resonator;

[0066] Step 4: when the vacuum degree of the vacuum box 4 is less than P, the piezoelectric exciter 6 is started to excite the hemispherical resonator 5 to be tested, and the vibration signal of the hemispherical resonator 5 to be tested is obtained by using the laser vibrometer 11;

[0067] The signal obtained by the laser vibrometer 11 is a vibration signal obtained after all the modes of the hemispherical resonator to be measured, except the second-order bending vibration mode, decay to disappearance;

[0068] Step 5, processing the vibration signal obtained in step 4 to obtain the resonant frequency, quality factor, frequency decomposition and inherent rigid axis orientation parameters of the hemispherical resonator to be measured;

[0069] Step 6: Repeat the process from step 2 to step 5 until all the hemispherical resonators to be tested on the rotating platform 2 have completed the test.

[0070] like Figure 3 The software function diagram of the present invention is shown. The motion controller mainly controls the rotation of the rotating platform and the release and closing of the electromagnetic limit pin. The x-axis is the rotation axis of the rotating platform. By setting a specific angle and clicking to start, the rotating platform will automatically close. After the rotating platform finishes rotating, the electromagnetic limit pin will automatically release.

[0071] Specific implementation method 7: This implementation method is different from specific implementation method 6 in that the value of P is 1×10 - 3 Pa.

[0072] The other steps and parameters are the same as those in the sixth embodiment.

[0073] Specific implementation eight: This implementation is different from specific implementation six or seven in that the specific process of step 5 is as follows:

[0074] Fit the vibration signal obtained in step 4:

[0075] w(θ,t)=[(Acos2θ ω cosωt+Asin2θ ω cos(ω+Δω)t]e -t / τ

[0076] Among them, w(θ,t) is the fitting signal, t is time, ω is the resonant frequency, τ is the time constant, Δω is the frequency decomposition, θ ω is the azimuth of the inherent rigid axis, A is the vibration amplitude at the lip edge of the hemispherical resonator, and e is the base of the natural logarithm;

[0077] By extracting the envelope information of the fitting signal, the resonant frequency, quality factor, frequency splitting and inherent rigid axis azimuth parameters of the hemispherical resonator are obtained.

[0078] Due to the limitations of the manufacturing process, the actual machined hemispherical resonator will have problems of uneven circumferential mass and energy attenuation. The method of this embodiment can improve the test accuracy of the resonance frequency, quality factor, frequency splitting and inherent rigid axis azimuth parameters.

[0079] The other steps and parameters are the same as those in the sixth or seventh embodiment.

[0080] Experimental Section

[0081] By carrying out batch testing on the performance of hemispherical resonant gyroscopes, the reliability of the batch testing system and method proposed in the present invention is verified, and the problems of low testing efficiency and testing accuracy of the performance of hemispherical resonant gyroscopes are solved.

[0082] Test results such as Figure 4 As shown, by fitting the collected signal and then performing signal envelope extraction on the fitted signal, the main vibration parameters of the hemispherical resonator can be obtained. The resonant frequency of the resonator is 4910.1 Hz, the frequency splitting is 0.1238 Hz, the rigid axis angle is 12.78 degrees, and the quality factor is 5.12 million.

[0083] The above calculation examples of the present invention are only used to explain the calculation model and calculation process of the present invention in detail, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A hemispherical resonator batch testing system, characterized in that: The system comprises a rotating platform (2), a resonator fixture (3), a vacuum box (4), a hemispherical resonator (5), a piezoelectric exciter (6), a glass flange (7), a vacuum turntable (8) and a laser vibrometer (11), wherein: The rotating platform (2), the resonator fixture (3), the hemispherical resonator (5), the piezoelectric exciter (6) and the vacuum turntable (8) are arranged inside the vacuum box (4); The rotating platform (2) is a circular turntable, and a plurality of resonator clamps (3) are evenly arranged along the circumferential direction on the upper surface of the rotating platform (2); The resonator fixture (3) is used to fix the hemispherical resonator (5) on the rotating platform (2); The rotating platform (2) is fixedly arranged on a vacuum turntable (8), and the vacuum turntable (8) is used to drive the rotating platform (2) to rotate to realize the switching of different hemispherical resonators (5); The piezoelectric exciter (6) is arranged on the side of the rotating platform (2), and the piezoelectric exciter (6) is used to excite the hemispherical resonator (5); The laser vibrometer (11) is arranged outside the vacuum box (4), and the measuring light path of the laser vibrometer (11) is focused on the lip edge position of the hemispherical resonator (5) through a glass flange (7) arranged on the vacuum box (4).

2. A hemispherical resonator batch testing system according to claim 1, characterized in that: The system also includes a turntable controller, a laser vibrometer controller and a host computer. The vacuum turntable (8) is controlled by the turntable controller, the laser vibrometer (11) is controlled by the laser vibrometer controller, the turntable controller communicates with the host computer via a serial port, and the laser vibrometer controller communicates with the host computer via a network port.

3. A hemispherical resonator batch testing system according to claim 2, characterized in that: The system further comprises an electromagnetic limit pin (1), which is arranged inside the vacuum box (4) and below the rotating platform (2), and is used to limit the free rotation of the rotating platform (2) after being controlled by a network controller.

4. A hemispherical resonator batch testing system according to claim 3, characterized in that: The system also includes a grating (9) and a grating reading head (10), wherein the grating (9) and the grating reading head (10) are arranged inside the vacuum box (4) and fixed on the vacuum turntable (8), and are used to provide real-time feedback of the rotation angle of the rotating platform (2) to the turntable controller.

5. A hemispherical resonator batch testing system according to claim 4, characterized in that: The vacuum box (4) and the laser vibrometer (11) are arranged on an air-floating shock-absorbing platform.

6. A hemispherical resonator batch testing method, characterized in that: The method specifically comprises the following steps: Step 1, fix the hemispherical resonator (5) to be tested on the upper surface of the rotating platform (2) through the resonator fixture (3) in turn, then close the vacuum box (4) and start evacuating; Step 2, the host computer sends a command to the electromagnetic limit pin (1) through the network controller to enable it, and controls the vacuum turntable (8) to rotate through the turntable controller. The vacuum turntable (8) drives the rotating platform (2) to rotate so that the hemispherical resonator to be measured rotates to the position to be measured, and then the electromagnetic limit pin (1) is released to limit the circumferential rotation of the rotating platform (2); Step 3, after turning on the laser vibrometer (11), adjust the focal length of the laser so that the focal point is located at the lip edge of the hemispherical resonator; Step 4: when the vacuum degree of the vacuum box (4) is less than P, the piezoelectric exciter (6) is started to excite the hemispherical resonator (5) to be tested, and a vibration signal of the hemispherical resonator (5) to be tested is obtained by using a laser vibrometer (11); Step 5, processing the vibration signal obtained in step 4 to obtain the resonant frequency, quality factor, frequency decomposition and inherent rigid axis orientation parameters of the hemispherical resonator to be measured; Step 6: Repeat the process from step 2 to step 5 until all the hemispherical resonators to be tested on the rotating platform (2) have completed the test.

7. A hemispherical resonator batch testing method according to claim 6, characterized in that: The value of P is 1×10 -3 Pa.

8. A hemispherical resonator batch testing method according to claim 7, characterized in that: The specific process of step 5 is as follows: Fit the vibration signal obtained in step 4: w(θ,t)=[(Acos2θ ω cosωt+Asin2θ ω cos(ω+Δω)t]e -t / τ Among them, w(θ,t) is the fitting signal, t is time, ω is the resonant frequency, τ is the time constant, Δω is the frequency decomposition, θ ω is the azimuth of the inherent rigid axis, A is the vibration amplitude at the lip edge of the hemispherical resonator, and e is the base of the natural logarithm; By extracting the envelope information of the fitting signal, the resonant frequency, quality factor, frequency splitting and inherent rigid axis azimuth parameters of the hemispherical resonator are obtained.

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