阅读说明：本技术 一种半球谐振子质量不平衡缺陷的检测装置及方法 (Detection device and method for mass unbalance defect of hemispherical harmonic oscillator ) 是由 柳凯 王建青 何晓霞 黄帅 党建军 张培新 李志杰 樊升封 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种半球谐振子质量不平衡缺陷的检测装置及方法,解决了谐振子机械平衡调平无法检测一次、二次、三次谐波质量缺陷的问题,本发明的检测装置,包括自动一维转台、激励电极以及激光测振仪,激励电极对谐振子的半球进行驻波激励,激光测振仪测定半球谐振子轴的自由端边缘点的微小振动,自动一维转台可以带动半球谐振子转动,使得激光测振仪可以测得谐振子轴的自由端上多个边缘点以及可以沿着不同方向测定振动；本发明的检测方法中激光测振仪从各方向测得0°方位点和45°方位点的微小振动,进而对该振动信号进行信号解调、低通滤波处理得到挠度值,解算出半球谐振子一次、二次、三次谐波质量不平衡量和方位角。(The invention discloses a detection device and a method for detecting the mass unbalance defect of a hemispherical harmonic oscillator, which solve the problem that the mechanical balance and leveling of the harmonic oscillator cannot detect the mass defect of primary, secondary and third harmonics, and the detection device comprises an automatic one-dimensional turntable, an excitation electrode and a laser vibration meter, wherein the excitation electrode carries out standing wave excitation on the hemisphere of the harmonic oscillator, the laser vibration meter measures the tiny vibration of the edge point of the free end of the axis of the hemispherical harmonic oscillator, and the automatic one-dimensional turntable can drive the hemispherical harmonic oscillator to rotate, so that the laser vibration meter can measure a plurality of edge points on the free end of the axis of the harmonic oscillator and can measure the vibration along different directions; in the detection method, the laser vibration meter measures the micro vibration of a 0-degree square point and a 45-degree square point from each direction, further performs signal demodulation and low-pass filtering on the vibration signal to obtain a deflection value, and solves the mass unbalance amount and the azimuth angle of the first harmonic wave, the second harmonic wave and the third harmonic wave of the hemispherical harmonic wave.)

1. The utility model provides a detection apparatus of hemisphere harmonic oscillator quality unbalance defect which characterized in that: comprises an automatic one-dimensional turntable (1), an excitation electrode (3) and a laser vibration meter (4);

the semi-spherical harmonic oscillator (2) to be detected is positioned above the automatic one-dimensional rotary table (1), the semi-spherical opening end of the semi-spherical harmonic oscillator (2) to be detected faces the automatic one-dimensional rotary table (1), a shaft arranged at the opening end is elastically connected with the center of the automatic one-dimensional rotary table (1), and a shaft arranged at the spherical end of the semi-spherical harmonic oscillator (2) to be detected is a free end;

the excitation electrodes (3) comprise two point electrodes which are symmetrically arranged at the left side and the right side of the spherical surface of the hemispherical harmonic oscillator (2) and are used for loading excitation to the hemispherical harmonic oscillator (2) to be detected to enable the hemispherical harmonic oscillator to vibrate;

the laser vibration meter (4) is used for collecting vibration information of the hemispherical harmonic oscillator (2) to be detected.

2. A detection method for a hemisphere harmonic oscillator mass unbalance defect is characterized by comprising the following steps: the device of claim 1, comprising the following steps:

step 1) detection of second harmonic mass unbalance of hemispherical harmonic oscillator (2)

Step 1.1), placing a laser vibration meter (4) right above a hemispherical resonator (2) to ensure that laser emitted by the laser vibration meter (4) is axially parallel to the hemispherical resonator (2) and laser spots of the laser are located at edge points of the free end face of the hemispherical resonator (2);

step 1.2) setting an initial marginal point of a laser spot of a laser vibration meter (4) falling on the end surface of the free end of the hemispherical harmonic oscillator (2) to be a 0-degree square point, carrying out standing wave excitation on the hemispherical harmonic oscillator (2) through an excitation electrode (3), and measuring a vibration signal of the 0-degree square point of the free end of the hemispherical harmonic oscillator (2) through the laser vibration meter (4) to obtain z (0, t), wherein t is time;

the automatic one-dimensional turntable (1) drives the hemispherical harmonic oscillator (2) to rotate 45 degrees anticlockwise, or the laser vibration meter (4) rotates 45 degrees around the shaft of the hemispherical harmonic oscillator (2), and at the moment, the laser spot of the laser vibration meter (4) falls on the edge point of the free end face of the hemispherical harmonic oscillator (2) and is marked as a 45-degree square point; measuring a vibration signal of a 45-degree square point of the free end of the hemispherical harmonic oscillator (2) by using a laser vibration meter (4) to obtain z (pi/4, t), wherein t is time;

step 1.3) carrying out signal demodulation on vibration signals z (0, t) and z (pi/4, t) of the 0-degree square position point and the 45-degree square position point by using standard signals, and carrying out low-pass filtering processing to obtain two corresponding deflection values which are respectively U₁(0)、U₁(π/4); the standard signal is equal to the frequency of the excitation electrode (3);

step 1.4) calculating the second harmonic quality unbalance of the hemispherical harmonic oscillator (2)Azimuth angleWherein the coefficient K₂Can be determined by experiments, and the value range is 0 < K₂＜1；

Step 2) detecting the mass unbalance of the first harmonic wave and the third harmonic wave of the hemispherical harmonic oscillator (2)

Step 2.1), placing the laser vibration meter (4) at the side of the hemispherical resonator (2) to ensure that laser emitted by the laser vibration meter (4) is vertical to the axial direction of the hemispherical resonator (2) and laser spots of the laser are located at the edge point of the free end face of the hemispherical resonator (2);

step 2.2) two corresponding deflection values, respectively U, are obtained in the same manner as in steps 1.2) and 1.3)₂(0)、U₂(π/4)；

Step 2.3) taking the position of the step 2.1 as an initial position, and driving the hemispherical harmonic oscillator (2) to rotate 90 degrees clockwise by using the automatic one-dimensional turntable (1), or horizontally rotating the laser vibration meter (4) by 90 degrees around the axis of the hemispherical harmonic oscillator (2);

step 2.4) two corresponding deflection values, respectively U, are again obtained in the same manner as in steps 1.2) and 1.3)₃(0)、U₃(π/4)；

Step 2.5) the deflection value U obtained in step 2.2₂(0)、U₂(π/4) and U obtained from step 2.4 deflection values₃(0)、U₃(pi/4) are respectively calculatedCalculating the first harmonic quality unbalance epsilon of harmonic oscillator₁Azimuth angleAnd harmonic oscillator third harmonic quality unbalance amount epsilon₃Azimuth angle

Azimuth angle

Azimuth angle

Wherein the coefficient K₁、K₃Can be determined by experiment, K₁Has a value range of 0 < K₁＜1，K₃Has a value range of 0 < K₃＜1。

3. The method for detecting and evaluating the mass imbalance of the hemispherical harmonic oscillator according to claim 2, characterized in that: the method also comprises the step of eliminating the quality defect of the fourth harmonic in advance by the hemispherical harmonic oscillator (2) to be tested before the step 1) is executed.

Technical Field

The invention relates to the field of microelectronic systems, in particular to a detection device and a detection method for a mass unbalance defect of a hemispherical harmonic oscillator.

Background

The hemispherical resonator gyro has the best performance and precision, and has the characteristics of high precision, good reliability, small volume, long service life, strong radiation resistance and the like. The hemispherical harmonic oscillator is a core component of the gyroscope, and the principle of the hemispherical harmonic oscillator requires that the harmonic oscillator is a completely symmetrical and uniform resonator. The actually processed harmonic oscillator always has some deviation from an ideal symmetrical shape and has circumferential asymmetry, namely, the mass of the oscillator is unbalanced, and the drift accuracy of the hemispherical resonator gyro is directly influenced. The existence of harmonic oscillator mass imbalance can cause harmonic oscillator natural frequency splitting, which is called frequency splitting. The frequency cracking value (frequency difference) is a key index for measuring the performance of the harmonic oscillator. The process of balancing the mass of the hemispherical harmonic oscillator, which is called leveling, is the most important operation in the adjusting process of the hemispherical resonant gyroscope, and the process determines the final precision of the gyroscope to a great extent.

The most important method for leveling the hemispherical harmonic oscillator is mechanical balance. Mechanical balancing is achieved by measuring the effect caused by mass imbalance and then using mechanical, laser, chemical, ion-plasma, etc. processes to effectively remove mass points or mass planes to minimize the effect. In order to realize the accurate positioning and quantitative removal of the mass points or mass surfaces of the harmonic oscillators, the magnitude and the position of the unbalanced mass distribution of the semi-spherical harmonic oscillators need to be accurately detected. In the prior art, the magnitude and the position of the fourth harmonic mass unbalance of the harmonic oscillator can be accurately detected, but no effective method and device for detecting the first harmonic mass unbalance, the second harmonic mass unbalance and the third harmonic mass unbalance exist.

At present, the mechanical balancing method of the harmonic oscillator mainly realizes the quality defect balance of the fourth harmonic of the harmonic oscillator through laser removal or ion beam removal. Because the fourth harmonic quality defect has the largest influence on frequency cracking in the harmonic quality defects, the harmonic frequency cracking value can be quite small by leveling the harmonic quality defects by a harmonic mechanical balance method. However, the harmonic oscillator mechanical balance leveling method has the following defects: firstly, although the harmonic oscillator frequency cracking value can be reduced to a certain extent by leveling through a harmonic oscillator mechanical balance method, for a high-precision hemispherical resonant gyroscope, the requirement of the performance of the gyroscope cannot be met only by eliminating mass unbalance of fourth harmonic; the frequency cracking of the harmonic oscillator is further reduced by detecting and eliminating the first third mass unbalance harmonic, so that the defect can be effectively made up; secondly, under the vibration condition, the influence of the first harmonic, the second harmonic and the third harmonic of the quality defect on the precision performance of the gyroscope is obviously increased, the prior mechanical balance method only aims at the fourth harmonic, cannot identify the first third harmonic, and is not enough to enable the gyroscope to still keep high precision under the vibration condition.

Disclosure of Invention

The invention provides a detection device and a detection method for the quality unbalance defect of a hemispherical harmonic oscillator, aiming at solving the problem that the mechanical balance leveling method of the harmonic oscillator in the prior art cannot detect the quality defect of primary, secondary and third harmonics.

A detection device for the mass unbalance defect of a hemispherical harmonic oscillator is characterized in that: the device comprises an automatic one-dimensional turntable, an excitation electrode and a laser vibrometer;

the semi-spherical harmonic oscillator to be detected is positioned above the automatic one-dimensional turntable, the semi-spherical opening end of the semi-spherical harmonic oscillator to be detected faces the automatic one-dimensional turntable, a shaft arranged at the opening end is elastically connected with the center of the automatic one-dimensional turntable, and a shaft arranged at the spherical end of the semi-spherical harmonic oscillator to be detected is a free end;

the excitation electrodes comprise two point electrodes which are symmetrically arranged at the left side and the right side of the spherical surface of the hemispherical harmonic oscillator and are used for loading excitation to the hemispherical harmonic oscillator to be detected to enable the hemispherical harmonic oscillator to be detected to vibrate;

the laser vibration meter is used for collecting vibration information of the hemispherical harmonic oscillator to be detected.

A detection method for the mass unbalance defect of a hemispherical harmonic oscillator is characterized by comprising the following steps: the detection device for the mass unbalance defect of the hemispherical harmonic oscillator comprises the following specific implementation steps:

step 1) detection of second harmonic mass unbalance of hemispherical harmonic oscillator

Step 1.1) placing a laser vibration meter right above a hemispherical harmonic oscillator to ensure that laser emitted by the laser vibration meter is axially parallel to the hemispherical harmonic oscillator and laser spots of the laser fall on edge points of the free end face of the hemispherical harmonic oscillator;

step 1.2) setting an initial edge point of a laser spot of a laser vibration meter falling on the end surface of the free end of the hemispherical resonator to be a 0-degree square point, carrying out standing wave excitation on the hemispherical resonator through an excitation electrode, and measuring a vibration signal of the 0-degree square point of the free end of the hemispherical resonator through the laser vibration meter to obtain z (0, t), wherein t is time;

the automatic one-dimensional turntable drives the hemispherical harmonic oscillator to rotate 45 degrees anticlockwise, or the laser vibration meter rotates 45 degrees around the shaft of the hemispherical harmonic oscillator 2, and at the moment, the laser spot of the laser vibration meter falls on the edge point of the free end face of the hemispherical harmonic oscillator and is marked as a 45-degree square point; measuring a vibration signal of a 45-degree square point of the free end of the hemispherical harmonic oscillator by using a laser vibration meter to obtain z (pi/4, t), wherein t is time;

step 1.3) carrying out signal demodulation on vibration signals z (0, t) and z (pi/4, t) of the 0-degree square position point and the 45-degree square position point by using standard signals, and carrying out low-pass filtering processing to obtain two corresponding deflection values which are respectively U₁(0)、U₁(π/4); the standard signal is equal to the frequency of the excitation electrode;

step 1.4) calculating the second harmonic quality unbalance of the hemispherical harmonic oscillatorAzimuth angleWherein the coefficient K₂Can be determined by experiments, and the value range is 0 < K₂＜1；

Step 2) detecting the mass unbalance of the first harmonic wave and the third harmonic wave of the hemispherical harmonic oscillator

Step 2.1) placing a laser vibration meter at the side of the hemispherical harmonic oscillator to ensure that laser emitted by the laser vibration meter is vertical to the axial direction of the hemispherical harmonic oscillator and laser spots of the laser are located at the edge point of the free end face of the hemispherical harmonic oscillator;

step 2.2) two corresponding deflection values, respectively U, are obtained in the same manner as in steps 1.2) and 1.3)₂(0)、U₂(π/4)；

Step 2.3) taking the position of the step 2.1 as an initial position, and driving the hemispherical harmonic oscillator to rotate 90 degrees clockwise by using the automatic one-dimensional turntable, or horizontally rotating the laser vibration meter by 90 degrees around the axis of the hemispherical harmonic oscillator;

step 2.4) two corresponding deflection values, respectively U, are again obtained in the same manner as in steps 1.2) and 1.3)₃(0)、U₃(π/4)；

Step 2.5) the deflection value U obtained in step 2.2₂(0)、U₂(π/4) and U obtained from step 2.4 deflection values₃(0)、U₃(pi/4) respectively calculating the first harmonic quality unbalance amount epsilon of the harmonic oscillator₁Azimuth angleAnd harmonic oscillator third harmonic quality unbalance amount epsilon₃Azimuth angle

Azimuth angle

Azimuth angle

Wherein the coefficient K₁、K₃Can be determined by experiment, K₁Has a value range of 0 < K₁＜1，K₃Has a value range of 0 < K₃＜1。

Further, the method also comprises the step of eliminating the quality defect of the fourth harmonic in advance by the hemispherical harmonic oscillator to be tested before the step 1) is executed.

Compared with the prior art, the beneficial effects are as follows:

the detection device for the mass unbalance defect of the hemispherical harmonic oscillator has a simple structure, is convenient to use, and can meet the requirements of detection of the mass defect of the primary harmonic, the secondary harmonic and the third harmonic of the hemispherical harmonic oscillator. The excitation electrode in the detection device carries out standing wave excitation on a hemisphere of the harmonic oscillator, a laser vibration meter is used for measuring a tiny vibration signal of an edge point of a free end of a hemispherical harmonic oscillator shaft, and an automatic one-dimensional turntable can drive the hemispherical harmonic oscillator connected with the center of the turntable to rotate, so that the laser vibration meter can measure a plurality of edge points on the free end of the harmonic oscillator shaft and measure vibration in different directions;

the invention relates to a detection method of a hemisphere harmonic oscillator mass unbalance defect, which is characterized in that a micro vibration signal of a 0-degree square point and a 45-degree square point measured from each direction by a laser vibration meter is subjected to signal demodulation and low-pass filtering to obtain a corresponding flexibility value, and the mass unbalance amount and the azimuth angle of primary, secondary and third harmonics of the hemisphere harmonic oscillator are solved, so that the mass defect of the harmonic oscillator is determined.

Drawings

Fig. 1 is a schematic structural diagram of a device for detecting a mass imbalance defect of a hemispherical harmonic oscillator in step 2) in the embodiment of the present invention;

fig. 2 is a schematic structural diagram of the apparatus for detecting the mass imbalance defect of the hemispherical harmonic oscillator in step 6) in the embodiment of the present invention;

FIG. 3 is a schematic flow chart illustrating a method for detecting a mass imbalance defect of a hemispherical resonator according to an embodiment of the present invention;

FIG. 4 is a schematic flow chart of step 4) in the method for detecting a mass imbalance defect of a hemispherical resonator according to an embodiment of the present invention;

in the figure: 1-automatic one-dimensional turntable, 2-hemispherical harmonic oscillator, 3-exciting electrode and 4-laser vibrometer.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

As shown in fig. 1 and 2, the detection device for detecting the mass imbalance defect of the hemispherical harmonic oscillator comprises an automatic one-dimensional turntable 1, an excitation electrode 3 and a laser vibration meter 4; the hemisphere harmonic oscillator 2 to be detected is located above the automatic one-dimensional rotary table 1, the hemisphere opening end of the hemisphere harmonic oscillator 2 to be detected faces the automatic one-dimensional rotary table 1, a shaft arranged at the hemisphere opening end of the hemisphere harmonic oscillator 2 to be detected is elastically connected with the automatic one-dimensional rotary table 1, and a shaft arranged at the spherical surface end of the hemisphere harmonic oscillator 2 to be detected is a free end; the excitation electrodes 3 comprise two point electrodes which are symmetrically arranged at the left side and the right side of the spherical surface of the hemispherical harmonic oscillator 2 and are used for loading excitation to the hemispherical harmonic oscillator 2 to be detected so as to enable the hemispherical harmonic oscillator to vibrate; the laser vibration meter 4 is used for collecting vibration information of the hemispherical harmonic oscillator 2 to be detected.

As shown in fig. 1 and 2, a three-axis orthogonal coordinate system is set up on the detection device of the mass unbalance defect of the hemispherical resonator, the elastic connection position of the axis of the hemispherical resonator 2 and the center position of the automatic one-dimensional turntable 1 is a coordinate origin, the free end of the hemispherical resonator axis is a Z axis, the Z axis is positive upward, the X axis is positive rightward, the direction perpendicular to both the X axis and the Z axis is a Y direction, and the direction from the outside to the paper surface is a Y axis positive direction.

In this embodiment, the detection and identification device for the mass unbalance defect of the hemispherical resonator is used to detect the mass unbalance of the hemispherical resonator with a diameter of 30mm, as shown in fig. 3, the detection method for the mass unbalance defect of the hemispherical resonator specifically includes the following steps:

step 1) eliminating the quality defect of fourth harmonic in advance for the hemispherical harmonic oscillator 2;

step 2) as shown in fig. 1, placing a laser vibration meter 4 right above the hemispherical resonator 2 to ensure that laser emitted by the laser vibration meter 4 is parallel to the axial direction of the hemispherical resonator 2 and laser spots of the laser fall on the edge point of the free end surface of the hemispherical resonator shaft;

step 3) setting an initial edge point of a laser spot of a laser vibration meter 4, which falls on the end surface of the free end of the hemispherical resonator shaft, as a 0-degree square point, carrying out standing wave excitation on the hemispherical resonator 2 by using an excitation electrode 3 at a frequency lambda and a constant amplitude A, measuring a vibration signal of the 0-degree square point of the free end of the hemispherical resonator shaft by using the laser vibration meter 4, and recording the vibration signal as z (0, t), wherein t is time;

the automatic one-dimensional turntable 1 drives the hemispherical harmonic oscillator 2 to rotate 45 degrees anticlockwise, so that the edge point of a laser spot of the laser vibration meter 4, which falls on the end face of the free end of the hemispherical harmonic oscillator shaft, is marked as a 45-degree square point; the frequency and the amplitude of the exciting electrode 3 are unchanged, the semi-spherical harmonic oscillator 2 is excited by standing waves, and a vibration signal z (pi/4, t) of a square point of 45 degrees is measured by a laser vibration meter 4, wherein t is time;

namely measuring vibration signals Z (0, t) and Z (pi/4, t) of the hemispherical harmonic oscillator 2 at 0-degree and 45-degree square points in the Z direction;

step 4) comparing the vibration signals of 0 degree azimuth and 45 degree azimuth with the standard signal sin (lambda)^*t) (where the frequency of the reference signal is equal to the frequency of the excitation electrode 3, i.e. λ)^*λ) and low-pass filtering to obtain corresponding deflection values, U each₁(0)、U₁(π/4)；

Step 5) calculating the second harmonic defect parameters of the hemispherical harmonic oscillator Azimuth angleDetermination of the coefficient K by experiment₂(0＜K₂Less than 1), obtaining the second harmonic quality unbalance amount epsilon of the hemispherical harmonic oscillator₁；

Step 6) as shown in fig. 2, placing the laser vibration meter 4 on the left side of the hemispherical resonator 2 to ensure that the laser emitted by the laser vibration meter 4 is vertical to the axial direction of the hemispherical resonator 2, and the laser spot falls on the edge point of the free end surface of the hemispherical resonator shaft, so that the laser emitted by the laser vibration meter 4 is in the same direction as the positive direction of the laser X;

step 7), the automatic one-dimensional turntable 1 drives the hemispherical harmonic oscillator 2 to rotate by any angle, so that a laser spot of the laser vibration meter 4 falls on any point of the edge of the free end face of the hemispherical harmonic oscillator shaft, and the edge point is set to be a 0-degree square point;

step 8), standing wave excitation is carried out on the hemispherical harmonic oscillator 2 by the exciting electrode 3 with the frequency of lambda and the constant amplitude A, and a vibration signal x (0, t) of a 0-degree square point is measured by the laser vibration meter 4, wherein t is time;

the automatic one-dimensional turntable 1 drives the hemispherical harmonic oscillator 2 to rotate 45 degrees anticlockwise, so that a laser spot of a laser vibration meter 4 falls at a 45-degree position of the edge of the free end face of the hemispherical harmonic oscillator shaft, and a vibration signal x (pi/4, t) of the harmonic oscillator 2 in the 45-degree position is measured through the laser vibration meter 4, wherein t is time; obtaining vibration signals X (0, t) and X (pi/4, t) of the hemispherical harmonic oscillator 2 at the 0-degree and 45-degree square points in the X direction;

step 9) using standard signal sin (lambda) for vibration signals x (0, t) and x (pi/4, t)^*t)(λ^*λ) and low-pass filtering to obtain corresponding deflection values, U each₂(0)、U₂(π/4)；

Step 10) taking the position of the hemispherical resonator 2 rotated by any angle in the step 7) as an initial position, driving the hemispherical resonator 2 to rotate 90 degrees clockwise by using the automatic one-dimensional turntable 1, and keeping the position of the laser vibration meter 4 unchanged, wherein the measurement direction of the laser vibration meter 4 is positive to the measurement direction of the laser vibration meter in the step 7) as the Y axis; here, the laser vibration meter 4 may also be rotated by 90 ° horizontally counterclockwise around the Z axis, so that the laser emitted by the laser vibration meter is in the same direction as the positive direction of the Y axis; setting the edge point of the laser spot of the laser vibration meter 4 falling on the end face of the free end of the hemispherical harmonic oscillator shaft as a 0-degree square point;

step 11), exciting the electrodes 3 with constant frequency and amplitude, exciting the semi-spherical harmonic oscillator 2 by standing waves, and measuring a vibration signal y (0, t) of a 0-degree square point at the free end of the semi-spherical harmonic oscillator shaft by a laser vibration meter 4, wherein t is time;

the automatic one-dimensional turntable 1 drives the hemispherical harmonic oscillator 2 to rotate 45 degrees anticlockwise, so that a laser spot of the laser vibration meter (4) falls on a 45-degree azimuth point of the edge of the free end face of the hemispherical harmonic oscillator shaft, and a vibration signal y (y) of the harmonic oscillator 2 in a 45-degree azimuth is measured by the laser vibration meter 4π/4T), where t is time;

namely, vibration signals y (0, t), y (0, t) of the hemispherical harmonic oscillator 2 at the 0-degree square position and the 45-degree square position in the X directionπ/4,t)；

Step 12) to the vibration signals y (0, t), y (π/4T) is compared with the standard signal sin (lambda)^*t)(λ^*λ) and low-pass filtering to obtain corresponding deflection values, U each₃(0)、U₃(π/4)；

Step 13) calculating the first harmonic quality defect parameters of the hemispherical harmonic oscillatorAzimuth angleHarmonic oscillator third harmonic quality defect parameter Azimuth angle Determination of the coefficient K by experiment₁、K₃(0＜K₁＜1，0＜K₃Less than 1), obtaining the mass unbalance amount epsilon of the first harmonic wave and the second harmonic wave of the hemispherical harmonic oscillator₁、ε₃。

In the detection method for the mass unbalance defect of the hemispherical harmonic oscillator, a laser vibration meter 4 respectively measures vibration signals in an X direction, a Y direction and a Z direction at a 0-degree square position and a 45-degree square position of the free end of a hemispherical harmonic oscillator shaft, wherein the 0-degree square position and the 45-degree square position are any two points of the edge of the free end of the hemispherical harmonic oscillator shaft, and the two points need to meet the following conditions: the 45-degree square locus is positioned in the clockwise direction of the 0-degree square locus, and the corresponding central angle between the two points is 45 degrees.

In order to ensure that the 0 ° square point and the 45 ° square point satisfy the condition, in steps 3), 8), 11), when the laser vibration meter 4 sequentially measures the 0 ° square point and the 45 ° square point, where the 0 ° square point is any point of the edge of the free end of the hemispherical resonator shaft, and when the 45 ° square point is measured, the laser spot of the laser vibration meter 4 can fall at the 45 ° azimuth point by the following two ways:

mode 1: the positions and states of other parts in the detection device for the mass unbalance defect of the hemispherical harmonic oscillator are unchanged, and only the automatic one-dimensional turntable 1 drives the hemispherical harmonic oscillator 2 to rotate anticlockwise by 45 degrees;

mode 2: the laser vibrometer 4 is rotated by 45 ° around the axis (or Z-axis) of the hemispherical resonator 2.

Wherein, the specific processes of the steps 4), 9) and 12) are as follows:

(1) vibration signalAre all recorded asAccording to the vibration principle, the vibration signal measured by the vibration meter can be written as

In the formula, t is time，The azimuth angle of the hemispherical harmonic oscillator 2 to be detected is shown;for the hemisphere harmonic oscillator 2 to be measured at the azimuth angleIts natural frequency vibration amplitude when present; omega is the natural frequency of the hemispherical harmonic oscillator 2 to be measured; alpha is the inherent vibration phase of the hemispherical harmonic oscillator 2 to be detected;for the hemisphere harmonic oscillator 2 to be measured at the azimuth angleThe forced vibration amplitude generated by the excitation is obtained when the vibration is processed; and lambda is the frequency of the excitation electrode for carrying out standing wave excitation on the hemispherical harmonic oscillator 2 to be tested.

(2) The vibration signal is divided into a standard signal sin (lambda)^*t) demodulating the signal to obtain a signal Z_λ：

That is, the vibration signal is used as an input signal, and the multiplier multiplies the vibration signal by the reference signal sin (λ)^*t), (where λ)^*λ) trigonometric function is simplified to:

in the above formula, t is the time,the azimuth angle of the hemispherical harmonic oscillator 2 to be detected is shown;is a vibration signal; sin (lambda)^*t) is a standard signal;for the hemisphere harmonic oscillator 2 to be measured at the azimuth angleIts natural frequency vibration amplitude when present;for the hemisphere harmonic oscillator 2 to be measured at the azimuth angleThe forced vibration amplitude generated by the excitation is obtained when the vibration is processed; omega is the natural frequency of the hemispherical harmonic oscillator 2 to be measured; alpha is the inherent vibration phase of the hemispherical harmonic oscillator 2 to be detected; and lambda is the frequency of the excitation electrode for carrying out standing wave excitation on the hemispherical harmonic oscillator 2 to be tested.

(3) Signal Z after signal demodulation_λLow-pass filtering to obtain the flexibility value with the output signal as the detection point

In the formula, Z_λIs a signal after the demodulation of the signal,for the hemisphere harmonic oscillator 2 to be measured at the azimuth angleAnd the forced vibration amplitude generated by the excitation of the vibration generator.

The above disclosure is only for the specific embodiment of the present invention, but the embodiment of the present invention is not limited thereto, and any variations that can be made by those skilled in the art should fall within the scope of the present invention.