Device and method for measuring inclination angle of spherical reflector of laser gyroscope

Abstract

The invention discloses a laser gyroscope spherical reflector inclination angle measuring device and method, and relates to the technical field of laser gyroscopes, the laser gyroscope spherical reflector inclination angle measuring device comprises a frequency locker connected with a laser light source, a photoelectric detector, a diaphragm, a convex lens, a plano-convex lens, a semi-transparent semi-reflecting mirror, a spherical mirror C, a laser gyroscope resonant cavity and a CCD camera; a laser signal emitted by the laser light source sequentially passes through the diaphragm, the convex lens and the plano-convex lens and then enters the laser gyroscope resonant cavity, forward light propagating in the clockwise direction in the laser gyroscope resonant cavity is emitted after being overlapped for multiple times, and emergent light enters the semi-transparent semi-reflecting mirror and then is divided into two parts, one part of laser signals sequentially pass through the photoelectric detector and the frequency locker, the other part of laser signals sequentially enter the spherical mirror C and the CCD camera, and the laser gyroscope spherical mirror inclination angle is measured by measuring emergent light of the resonant cavity, so that the spherical mirror inclination angle value caused by piezoelectric ceramic nonlinearity is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of laser gyroscopes, and in particular to a device and method for measuring the inclination angle of a spherical reflector of a laser gyroscope. Background Art

[0002] The laser gyroscope is an angular velocity measurement sensor based on the Sagnac effect. It has the advantages of strong reliability, high stability, large dynamic range, small size and long service life. It is an ideal component of the strapdown inertial navigation system and is widely used in national defense, military, aerospace and other fields.

[0003] During the frequency locking process, the laser gyro usually uses the method of stabilizing the resonant cavity length to stabilize the longitudinal mode frequency of the resonant cavity. The cavity length control of the laser gyro resonant cavity is generally achieved by pushing and pulling the spherical mirror by piezoelectric ceramic deformation. By adjusting the driving voltage of the piezoelectric ceramic actuator connected to the spherical mirror of the laser gyro, the spherical mirror surface is slightly displaced to adjust the cavity length of the laser gyro resonant cavity. However, during the movement of the piezoelectric ceramic actuator, due to the influence of its own nonlinear characteristics, the spherical mirror may produce a small tilt angle. The schematic diagram of the piezoelectric ceramic actuator pushing and pulling the spherical mirror is shown in the figure. Figure 3 As shown in the figure, θ is the deflection angle of the spherical mirror, and h is the push-pull distance of the spherical mirror (generally in micrometers). The inclination of the spherical mirror will cause a certain deviation of the light emitted from the laser gyroscope resonant cavity, especially when it deviates close to the inner edge of the aperture hole in the optical path capillary hole, diffraction will occur, causing the measurement accuracy of the laser gyroscope to decrease during operation. Therefore, a device that can accurately measure the inclination of the spherical reflector in the laser gyroscope resonant cavity loop is needed.

[0004] The existing laser gyro resonant cavity outgoing light detection method mainly detects the intensity of the outgoing light, but does not detect the inclination angle of the outgoing light, resulting in a decrease in the measurement accuracy of the laser gyro when it is working. Summary of the invention

[0005] In view of the problem that the prior art does not detect the inclination angle of the outgoing light of the laser gyroscope resonant cavity, resulting in a decrease in the measurement accuracy of the laser gyroscope when it is working, the present invention proposes a laser gyroscope spherical reflector inclination angle measurement device and method, which measures the inclination angle of the spherical reflector by measuring the outgoing light of the resonant cavity, thereby solving the problems existing in the prior art.

[0006] A laser gyro spherical reflector inclination angle measuring device, comprising: a spherical mirror C, a CCD camera, a square laser gyro resonant cavity, a semi-transparent semi-reflective mirror, a plane reflector A and a plane reflector B; the four corner cavities of the laser gyro resonant cavity are sequentially arranged with a plane mirror A, a plane mirror B, a spherical mirror B and a spherical mirror A in a clockwise direction;

[0007] When the laser gyro resonant cavity and the semi-transparent and semi-reflective mirror constitute a measuring mechanism, the semi-transparent and semi-reflective mirror is arranged between the laser gyro resonant cavity and the spherical mirror C, and the CCD camera is arranged below the semi-transparent and semi-reflective mirror; the laser signal is incident on the laser gyro resonant cavity and propagates in a clockwise direction before being emitted, and the emitted light is incident on the semi-transparent and semi-reflective mirror and then reflected on the concave surface of the spherical mirror C, and the position S1 of the reflected light of the spherical mirror C on the CCD camera is recorded;

[0008] When the plane reflector A, the plane reflector B and the spherical mirror B and the spherical mirror A in the laser gyro resonant cavity form a measuring mechanism, and the plane reflector A, the plane reflector B, the spherical mirror A and the spherical mirror B are placed in a counterclockwise order at the corresponding positions of the four corner cavities of the laser gyro resonant cavity, the CCD camera is arranged below the measuring mechanism and the spherical mirror C; after the laser signal is incident on the plane reflector A, the reflected light passes through the spherical mirror A, the spherical mirror B and the plane reflector B in sequence and then is incident on the concave surface of the spherical mirror C, and the position S2 of the reflected light of the spherical mirror C on the CCD camera is recorded;

[0009] By measuring the distance between positions S1 and S2 and the straight-line distance between S2 and the spherical mirror C, the inclination angle of the spherical mirror A is calculated.

[0010] Furthermore, it also includes a photoelectric detector, a laser light source and a frequency locker connected to the laser light source; after the outgoing light is incident on the semi-transparent and semi-reflective mirror, a part of the laser signal passes through the photoelectric detector and the frequency locker in sequence and returns to the laser light source.

[0011] Furthermore, an aperture, a convex lens and a plano-convex mirror are placed in sequence between the laser light source and the measuring mechanism, and the midlines of the aperture, the convex lens, the plano-convex mirror and the semi-transparent and semi-reflective mirror are in a straight line.

[0012] Furthermore, the spherical mirror A is connected to a piezoelectric ceramic actuator A, and the spherical mirror B is connected to a piezoelectric ceramic actuator B.

[0013] Furthermore, the plane reflector A and the plane reflector B are both plane reflectors with a transmittance of 5%.

[0014] The present invention also includes a method for measuring the inclination angle of a laser gyro spherical reflector, comprising the following steps:

[0015] By adjusting the position and angle of the aperture, convex lens, plano-convex mirror and semi-transparent and semi-reflective mirror, the laser light path incident on the measuring mechanism is made to resonate;

[0016] The laser signal emitted by the laser light source passes through the aperture, convex lens and plano-convex mirror in sequence and then enters the laser gyro resonant cavity. It propagates in the laser gyro resonant cavity in a clockwise direction and then exits. The exiting light enters the semi-transparent and semi-reflective mirror and then reflects to the concave surface of the spherical mirror C. The position S1 of the reflected light of the spherical mirror C on the CCD camera is recorded.

[0017] Keep the optical path unchanged, remove the laser gyro resonant cavity, and place plane reflector A, spherical mirror A, spherical mirror B and plane reflector B in the four corner cavity positions of the original laser gyro resonant cavity in a counterclockwise order; the laser signal emitted by the laser light source is incident on the plane reflector A after passing through the aperture, convex lens and plano-convex mirror in sequence, and the reflected light is reflected from the plane reflector B to the semi-transparent semi-reflective mirror after passing through the spherical mirror A and spherical mirror B, and then the reflected light is incident on the concave surface of the spherical mirror C; by changing the inclination angle of the spherical mirror A, the position S2 of the reflected light of the spherical mirror C on the CCD camera at different inclination angles is recorded;

[0018] Measure the distance d between S1 and S2, and the straight-line distance d1 between S2 and the spherical mirror C, and take the product of d and the focal length of the spherical mirror C as the quotient of the product of d and d1 and the total transformation matrix of the laser signal transmitted in the laser gyro resonant cavity for one cycle to obtain the inclination angle of the spherical mirror A.

[0019] Furthermore, the laser light path of the incident measurement mechanism is made to resonate by adjusting the positions and angles of the aperture, the convex lens, the plano-convex mirror and the semi-transparent and semi-reflective mirror, which specifically includes the following steps:

[0020] Adjust the angles and positions of the frequency locker, aperture, convex lens, plano-convex mirror, and semi-transparent and semi-reflective mirror, and observe the light spot pattern on the CCD camera;

[0021] If the light spot on the CCD camera appears in the shape of multiple rings or patterns and there is no central bright spot, continue to adjust; if the light spot on the CCD camera appears in the shape of a ring or multiple rings and there is a bright spot in the center of the light spot, the laser light path is resonant.

[0022] Furthermore, the method measures the distance d between S1 and S2, the straight-line distance d1 between S2 and the spherical mirror C, and calculates the product of d and the focal length of the spherical mirror C and the product of d1 and the total transformation matrix of the laser signal transmitted in the laser gyro resonant cavity for one cycle to obtain the inclination angle of the spherical mirror A, which specifically includes the following steps:

[0023] Let L i is the length of each arm of the laser gyro resonant cavity loop. In the square resonant cavity, L1=L2=L3=L4=12.5cm, A i is the incident angle of each reflector, which ranges from 0° to 90°; wherein i=1, 2, 3, 4;

[0024] When the reflector is misaligned, the actual optical path in the ring resonator is:

[0025] MV0=V

[0026] Where M is the total transformation matrix of the light in the ring resonator, V is the 5×5 five-frequency ray vector matrix, V0 is the original vector matrix; and:

[0027] M=ΠM i

[0028] V=[r x r′ x r y r′ y 1] T

[0029] Among them, r x ′、r x ′ represents the inclination of the optical axis, r x 、r y represents the eccentricity of the optical axis, T is the matrix transpose, M i is the transmission matrix of each reflector, expressed as:

[0030] M i =M(θ i )·M(R i ,A i )·M(L i ),

[0031]

[0032]

[0033]

[0034] Then, M is:

[0035]

[0036] Among them, R i is the radius of curvature of the spherical mirror at the top of the resonant cavity; θ xi ,θ yi are the misalignment angles of the reflector in the meridian and sagittal planes respectively; θ i is the image rotation angle; the inclination angle of the reflector is θ, the distance between the points where the light is detected by the CCD camera before and after the deflection is d, and the straight-line distance from the point on the CCD camera to the spherical mirror C after the deflection is d1, then:

[0037]

[0038] Then the inclination angle θ is obtained as:

[0039]

[0040] Wherein, f represents the focal length of the spherical mirror C.

[0041] The present invention provides a laser gyro spherical reflector inclination angle measurement device and method, which has the following beneficial effects:

[0042] The present invention builds a measuring mechanism. In the resonant optical path, when the laser gyro resonant cavity and the semi-transparent and semi-reflective mirror constitute the measuring mechanism, after the laser signal propagates in the laser gyro resonant cavity in the clockwise direction, the outgoing light is incident on the semi-transparent and semi-reflective mirror and then reflects on the inner reflection surface of the spherical mirror C, so as to obtain the position of the reflected light of the spherical mirror C on the CCD camera; then, by keeping the optical path unchanged, the laser gyro resonant cavity is removed, and the plane reflector A, the spherical mirror A, the spherical mirror B and the plane reflector B are sequentially placed at the four corner cavity positions of the original laser gyro resonant cavity in a counterclockwise order, so as to obtain the position of the reflected light on the inner reflection surface of the spherical mirror C on the CCD camera, and the position on the CCD camera is obtained by measuring the measuring mechanism in two cases, so as to realize the measurement of the inclination angle of the laser gyro spherical mirror. The laser gyro spherical reflector inclination angle measuring device is simple, has low operation difficulty, is easy to implement in engineering, can provide guidance data for the assembly of the laser gyro resonant cavity, and has important significance in the cavity adjustment and screening of the laser gyro in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of a laser gyro spherical reflector inclination angle measuring device in an embodiment of the present invention;

[0044] Figure 2 Schematic diagram of the calibration process of the laser gyro spherical reflector inclination angle measurement method in an embodiment of the present invention;

[0045] Figure 3 It is a schematic diagram of a piezoelectric ceramic actuator pushing and pulling a spherical mirror in the background technology of the present invention;

[0046] Figure 4 Schematic diagram of the laser beam becoming thinner and focusing in an embodiment of the present invention.

[0047] In the figure: 1-frequency locker, 2-photodetector, 3-laser light source, 4-aperture, 5-convex lens, 6-plane mirror A; 7-plane mirror B, 8-semi-transparent and semi-reflective mirror, 9-spherical mirror C, 10-laser gyro resonant cavity, 11-programmable power supply, 12-spherical mirror A, 13-spherical mirror B, 14-CCD camera, 15-plane reflector A, 16-plane reflector B, 17-piezoelectric ceramic actuator A, 18-piezoelectric ceramic actuator B, 19-plano-convex mirror. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0049] The present invention discloses a device for measuring the inclination of a laser gyro spherical reflector, which includes a laser light source 3, an aperture 4, a convex lens 5, a plano-convex mirror 19, a laser gyro resonant cavity 10, a semi-transparent semi-reflective mirror 8, a photodetector 2, a frequency locker 1, a spherical mirror C9, a programmable power supply 11, a plane mirror A6, a plane mirror B7, a spherical mirror A and a piezoelectric ceramic actuator A12, a spherical mirror B and a piezoelectric ceramic actuator B13, and a CCD camera 14. The laser gyro resonant cavity is composed of two spherical mirrors and two plane mirrors. Spherical mirror A and spherical mirror B are connected to the piezoelectric ceramic actuator, and the two spherical mirrors can produce a small movement along the normal direction of the spherical mirror under the control of the piezoelectric ceramic actuator. The schematic diagram of the reflector inclination measuring device is shown as follows: Figure 1 As shown in the figure, the calibration process diagram of the reflector inclination measuring device is as follows Figure 2 shown.

[0050] exist Figure 1 In the figure, the black line represents the emitted light when the spherical mirror does not generate an inclination during the push-pull process of the piezoelectric ceramic actuator, and the gray line represents the emitted light when the spherical mirror generates an inclination during the push-pull process of the piezoelectric ceramic actuator; the laser signal emitted by the laser light source 3 passes through the aperture 4, the convex lens 5 and the plano-convex mirror 19 in sequence, and is then emitted into the laser gyro resonant cavity 10 by the plane mirror A6. After multiple superpositions, the forward light propagating in the clockwise direction in the resonant cavity 10 is emitted from the laser gyro resonant cavity 10 by the plane mirror B7. The light signal emitted from the laser gyro resonant cavity 10 is incident on the semi-transparent and semi-reflective mirror 8 and is divided into two parts. One part is incident on the photodetector 2 and the frequency locker 1 in sequence. The frequency locker 1 is connected to the laser light source 3 to adjust the incident light beam so that the optical path resonates, and the other part is incident on the spherical mirror C9 and the CCD camera 14 in sequence.

[0051] Figure 2 The middle gray line indicates the change of light at different inclination angles of spherical mirror A; the laser signal emitted by the laser light source passes through the aperture, convex lens, plano-convex mirror, 5% transmittance plane mirror A, 5% transmittance plane mirror B, spherical mirror A, spherical mirror B, spherical mirror C and CCD camera in sequence.

[0052] Figure 4 Schematic diagram of a plano-convex lens thinning and focusing a laser beam. Figure 1 , Figure 2 In the figure, the laser light beam emitted by the laser light source 3 passes through the aperture 4 and the convex lens 5, and then the plano-convex lens 19 is used to make the laser light beam finer and focused, thereby improving the beam quality and thus improving the precision and accuracy of the measurement optical path.

[0053] Based on the above-proposed laser gyro spherical reflector inclination angle measuring device, the present invention also provides a laser gyro spherical reflector inclination angle measuring method, and the specific implementation steps are as follows:

[0054] Step 1: Place the laser light source, aperture, convex lens, plano-convex mirror, laser gyro resonator, semi-transparent and semi-reflective mirror, photodetector, frequency locker, spherical mirror C, programmable power supply and CCD camera in the order shown in Figure 1. Figure 1 Arrange the positions in order and build the laser light path; use the inner side of the spherical surface of spherical mirror C as the reflecting surface.

[0055] In the optical path of the laser gyroscope, in order to make the optical path reach the resonant state, it is necessary to accurately adjust the position and angle of the frequency locker, aperture, convex lens, plano-convex lens and semi-transparent and semi-reflective mirror. The aperture can control the size and shape of the light beam. Adjusting the aperture position allows the light beam to completely pass through the center of the aperture to ensure that the laser beam propagates accurately in the optical path and minimize the divergence of the light beam; placing the aperture in a suitable position ensures that the light beam propagates accurately in the optical path and minimizes the divergence of the light beam. By fine-tuning the position of the aperture, ensure that the light beam completely passes through the aperture and reduces unnecessary optical losses. The semi-transparent and semi-reflective mirror can separate or merge the laser beam to form an interference optical path in the laser gyroscope; place the semi-transparent and semi-reflective mirror in a suitable position to ensure that the light beam passes through the center of the mirror surface, and by fine-tuning the angle and position of the semi-transparent and semi-reflective mirror, ensure that the separated light beam accurately coincides with the original light beam path. The convex lens can focus the light beam so that the light beam maintains the appropriate size and shape during propagation; the convex lens is placed in the optical path so that the light beam is properly focused after passing through the convex lens; by adjusting the position of the convex lens, the focal position of the light beam is adjusted to meet the requirements of the optical path. The plano-convex lens can further focus or collimate the light beam and enhance the propagation quality of the light beam; place the plano-convex lens in the optical path to ensure that the light beam forms a parallel or properly focused beam after passing through the lens. Adjust the position and angle of the plano-convex lens to make the propagation path of the light beam in the optical cavity more stable. The frequency locker is used to keep the frequency of the laser stable so that the laser frequency matches the resonant frequency of the optical cavity; adjust the current or voltage of the frequency locker to ensure that the output frequency of the laser is consistent with the resonant frequency of the optical cavity.

[0056] Step 2: Adjust the laser optical path so that the frequency of the laser is locked to the operating frequency of the laser gyro resonant cavity. Adjust the position and angle of each optical element to ensure that the laser beam is correctly focused and transmitted on each element; use a frequency locker to lock the frequency of the laser light source to the resonant frequency of the optical cavity, and adjust the frequency of the laser light source in real time to ensure that the optical cavity can maintain a resonant state under different conditions.

[0057] Step 3: Adjust the frequency locker and fine-tune the lens and aperture position in step 1 at the same time, and observe the light spot pattern on the screen.

[0058] Step 4: If the light spot on the light screen presents multiple rings or pattern shapes and there is no obvious central bright spot, repeat the step 3 operation until the light spot on the light screen presents a special shape such as a ring or multiple rings, a circle or an ellipse, and the center of the light spot is brighter. At this time, the light path is resonant. By detecting the light intensity or interference fringes in the optical cavity, it is determined whether the resonant state has been reached. If the light intensity reaches the maximum or the interference fringes are the clearest, it means that the light path has reached the resonant state; repeatedly fine-tune the frequency locker, aperture, convex lens, plano-convex lens and semi-transparent and semi-reflective mirror, observe the changes in light intensity and interference fringes, and ensure that the light path maintains a stable resonant state.

[0059] Step 5: Keep the optical path unchanged, remove the laser gyro resonant cavity, and place 5% transmittance plane mirror A, 5% transmittance plane mirror B, spherical mirror A and piezoelectric deflection table A, spherical mirror B and piezoelectric deflection table B at the original laser gyro resonant cavity reflector position. Two spherical mirrors are connected to two piezoelectric deflection tables. The lenses are placed as shown in the figure. Figure 2 shown.

[0060] Step 6: Change the inclination angle of spherical mirror A by controlling the piezoelectric deflection stage, and record the position S1 of the light beam on the CCD camera at different inclination angles; let the straight-line distance from S1 to spherical mirror C be d1.

[0061] Step 7: Remove the reflector added in step 5, place the laser gyro resonant cavity in its original position, change the position of the spherical mirror A through the programmable power supply, observe the position S2 of the light beam on the CCD camera, and assume that the straight-line distance from S2 to the spherical mirror C9 is d2; the distance between S2 and S1 is d, and the straight-line distances d1 and d2 between the positions S1 and S2 of the light beam on the CCD camera 14 and the spherical mirror C9 are calculated accordingly to obtain the inclination angle of the spherical mirror A12.

[0062] Let L i (i=1~4) is the length of each arm of the resonant cavity loop. In the square resonant cavity, L1=L2=L3=L4=12.5cm, A i (i=1~4) is the incident angle of each reflector, ranging from 0 to 90°. When the reflector is misaligned, the optical axis must reappear in the ring resonator. The solution to the actual optical path in the ring resonator is:

[0063] MV0=V

[0064] Where M is the total transformation matrix of the light in the ring resonator, V is the 5×5 five-frequency ray vector matrix, V0 is the original vector matrix; and:

[0065] M=ΠM i

[0066] V=[rx r′ x r y r′ y 1] T

[0067] r x ′、r x ′ represents the inclination of the optical axis, r x 、r y Indicates the eccentricity of the optical axis. M i is the transmission matrix of each reflector, which can be expressed as:

[0068] M i =M(θ i )·M(R i ,A i )·M(L i ),

[0069]

[0070]

[0071]

[0072] Then, M is:

[0073]

[0074] Where R i is the curvature radius of the spherical mirror at the top of the resonant cavity, which is 5 mm, θ xi ,θ yi are the misalignment angles of the reflector in the meridian and sagittal planes, θ i is the image rotation angle. The focal length of the spherical mirror C9 is set to 100 mm, the inclination angle of the reflector is set to θ, the distance between the points where the light is detected by the CCD camera 14 before and after the deflection is d, and the straight-line distance from the point on the CCD camera 14 to the spherical mirror C9 after the deflection is d1, and both d and d1 can be measured. Then the geometric relationship is:

[0075]

[0076] Then the inclination angle θ can be obtained as:

[0077]

[0078] The laser gyro spherical reflector inclination angle measuring device and method of the present invention realize the measurement of the inclination angle of the spherical mirror of the laser gyro resonant cavity, and realize the measurement of the inclination angle of the laser gyro spherical mirror by measuring the outgoing light of the resonant cavity, thereby obtaining the inclination angle value of the spherical mirror caused by the nonlinearity of piezoelectric ceramics. The laser gyro spherical reflector inclination angle measuring device is simple, has low operation difficulty, is easy to implement in engineering, can provide guidance data for the assembly of the laser gyro resonant cavity, and is of great significance in the later laser gyro cavity tuning and screening.

[0079] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A laser gyro spherical reflector inclination angle measuring device, characterized in that: include: A spherical mirror C (9), a CCD camera (14), a square laser gyro resonant cavity (10), a semi-transparent and semi-reflective mirror (8), a plane reflective mirror A (15) and a plane reflective mirror B (16); the four corner cavities of the laser gyro resonant cavity (10) are provided with a plane mirror A (6), a plane mirror B (7), a spherical mirror B (13) and a spherical mirror A (12) in sequence along a clockwise direction; When the laser gyro resonant cavity (10) and the semi-transparent and semi-reflective mirror (8) form a measuring mechanism, the semi-transparent and semi-reflective mirror (8) is arranged between the laser gyro resonant cavity (10) and the spherical mirror C (9), and the CCD camera (14) is arranged below the semi-transparent and semi-reflective mirror (8); a laser signal is incident on the laser gyro resonant cavity (10), propagates in a clockwise direction, and then is emitted; the emitted light is incident on the semi-transparent and semi-reflective mirror (8), and then is reflected onto the inner reflection surface of the spherical mirror C (9); and the position S1 of the reflected light of the spherical mirror C (9) on the CCD camera (14) is recorded; When the plane reflector A (15), the plane reflector B (16), the spherical mirror B (13) and the spherical mirror A (12) in the laser gyro resonant cavity (10) form a measuring mechanism, and the plane reflector A (15), the plane reflector B (16), the spherical mirror A (12) and the spherical mirror B (13) are sequentially placed in a counterclockwise order at positions corresponding to the four corner cavities of the laser gyro resonant cavity (10), the CCD camera (14) is arranged below the measuring mechanism and the spherical mirror C (9); after the laser signal is incident on the plane reflector A (15), the reflected light passes through the spherical mirror A (12), the spherical mirror B (13) and the plane reflector B (16) in sequence and then is incident on the inner reflection surface of the spherical mirror C (9), and the position S2 of the reflected light of the spherical mirror C (9) on the CCD camera (14) is recorded; By measuring the distance between positions S1 and S2 and the straight-line distance between S2 and the spherical mirror C (9), the inclination angle of the spherical mirror A (12) is calculated.

2. The laser gyro spherical reflector inclination angle measuring device according to claim 1, characterized in that: It also includes a photoelectric detector (2), a laser light source (3), and a frequency locker (1) connected to the laser light source (3); after the outgoing light is incident on the semi-transparent and semi-reflective mirror (8), a portion of the laser signal passes through the photoelectric detector (2) and the frequency locker (1) in sequence and returns to the laser light source (3).

3. The laser gyro spherical reflector inclination angle measuring device according to claim 2, characterized in that: An aperture (4), a convex lens (5) and a plano-convex mirror (19) are sequentially placed between the laser light source (3) and the measuring mechanism, and the center lines of the aperture (4), the convex lens (5), the plano-convex mirror (19) and the semi-transparent and semi-reflective mirror (8) are in a straight line.

4. The laser gyro spherical reflector inclination angle measuring device according to claim 1, characterized in that: The spherical mirror A (12) is connected to a piezoelectric ceramic actuator A (17), and the spherical mirror B (13) is connected to a piezoelectric ceramic actuator B (18).

5. The laser gyro spherical reflector inclination angle measuring device according to claim 1, characterized in that: The plane reflector A (15) and the plane reflector B (16) are both plane reflectors with a transmittance of 5%.

6. A method for measuring the inclination angle of a laser gyro spherical reflector according to claim 3, characterized in that: The following steps are involved: By adjusting the positions and angles of the aperture (4), the convex lens (5), the plano-convex mirror (19) and the semi-transparent and semi-reflective mirror (8), the laser light path incident on the measuring mechanism is made to resonate; The laser signal emitted by the laser light source (3) passes through the aperture (4), the convex lens (5) and the plano-convex mirror (19) in sequence and then enters the laser gyro resonant cavity (10), propagates in the laser gyro resonant cavity (10) in a clockwise direction and then exits, and the exiting light enters the semi-transparent semi-reflective mirror (8) and then reflects onto the inner reflection surface of the spherical mirror C (9), and the position S1 of the reflected light of the spherical mirror C (9) on the CCD camera (14) is recorded; Keeping the optical path unchanged, the laser gyro resonant cavity (10) is removed, and a plane reflector A (15), a spherical mirror A (12), a spherical mirror B (13) and a plane reflector B (16) are placed in a counterclockwise order at the four corner cavity positions of the original laser gyro resonant cavity (10); the laser signal emitted by the laser light source (3) passes through the aperture (4), the convex lens (5) and the plano-convex mirror (19) in sequence and then enters the plane reflector A (15); the reflected light passes through the spherical mirror A (12) and the spherical mirror B (13), and then is reflected from the plane reflector B (16) to the semi-transparent semi-reflective mirror (8), and then enters the inner reflection surface of the spherical mirror C (9); by changing the inclination angle of the spherical mirror A (12), the position S2 of the reflected light of the spherical mirror C (9) on the CCD camera (14) at different inclination angles is recorded; The distance d between S1 and S2 and the straight-line distance d1 between S2 and the spherical mirror C (9) are measured, and the product of d and the focal length of the spherical mirror C is divided by the product of d1 and the total transformation matrix of the laser signal transmitted once in the laser gyro resonant cavity to obtain the inclination angle of the spherical mirror A (12).

7. A method for measuring the inclination angle of a laser gyro spherical reflector according to claim 6, characterized in that: The method specifically comprises the following steps: adjusting the positions and angles of the aperture (4), the convex lens (5), the plano-convex mirror (19) and the semi-transparent and semi-reflective mirror (8) so that the laser light path of the incident measurement mechanism resonates. Adjust the angles and positions of the frequency locker (1), the aperture (4), the convex lens (5), the plano-convex mirror (19) and the semi-transparent and semi-reflective mirror (8), and observe the light spot pattern on the CCD camera (14); If the light spot on the CCD camera (14) presents multiple rings or a pattern shape and no central bright spot appears, continue to adjust; if the light spot on the CCD camera (14) presents a ring shape or multiple ring shapes and a bright spot appears in the center of the light spot, the laser light path resonates.

8. The method for measuring the inclination angle of a laser gyro spherical reflector according to claim 6, characterized in that: The method measures the distance d between S1 and S2, the straight-line distance d1 between S2 and the spherical mirror C (9), and calculates the product of d and the focal length of the spherical mirror C and the product of d1 and the total transformation matrix of the laser signal transmitted in the laser gyro resonant cavity to obtain the inclination angle of the spherical mirror A (12), which specifically includes the following steps: Let L i is the length of each arm of the laser gyro resonant cavity loop. In the square resonant cavity, L1=L2=L3=L4=12.5cm, A i is the incident angle of each reflector, which ranges from 0° to 90°; wherein i=1, 2, 3, 4; When the reflector is misaligned, the actual optical path in the ring resonator is: MV0=V Where M is the total transformation matrix of the light in the ring resonator, V is the 5×5 five-frequency ray vector matrix, V0 is the original vector matrix; and: M=ΠM i V＝[r x r′ x r y r′ y 1] T Among them, r x ′、r x ′ represents the inclination of the optical axis, r x 、r y represents the eccentricity of the optical axis, T is the matrix transpose, M i is the transmission matrix of each reflector, expressed as: M i =M(θ i )·M(R i ,A i )·M(L i ), Then, M is: Among them, R i is the radius of curvature of the spherical mirror at the top of the resonant cavity; θ xi ,θ yi are the misalignment angles of the reflector in the meridian and sagittal planes respectively; θ i is the image rotation angle; the inclination angle of the reflector is θ, the distance between the points where the light is detected by the CCD camera before and after the deflection is d, and the straight-line distance from the point on the CCD camera to the spherical mirror C after the deflection is d1, then: Then the inclination angle θ is obtained as: Wherein, f represents the focal length of the spherical mirror C.

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