A method and system for testing scale factor of atomic interferometer gyroscope

Abstract

The present invention provides a method and system for testing the scale factor of an atomic interferometer gyroscope. The method comprises: securing the atomic interferometer gyroscope to a turntable, starting the atomic interferometer gyroscope, and using the phase of a Raman light DDS generator as the first output phase of the atomic interferometer gyroscope; starting the turntable and controlling it to rotate forward and backward at a given angular velocity, while recording the second output phase after lock-waist phase compensation; after the test, recording the third output phase of the atomic interferometer gyroscope when the turntable is stationary; calculating the average output of the atomic interferometer gyroscope when the turntable is stationary based on the first and third output phases; calculating the atomic interferometer gyroscope output at different given angular velocities based on the second output phase and the average output phase, and constructing a corresponding atomic interferometer gyroscope input-output model; and solving the model using least squares fitting to obtain the scale factor. This solution not only has strong resistance to environmental vibration interference and high test accuracy, but also has fast measurement speed and high efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of quantum precision measurement, and in particular relates to a method and system for testing the scale factor of an atomic interferometer gyroscope. Background Art

[0002] As a new generation of inertial measurement instruments, atomic interferometer gyroscopes (AIMGs) hold great promise for application. The scale factor of an AIMG is the ratio of its output to its input. Scale factor nonlinearity and scale factor repeatability, respectively, measure the maximum deviation of the gyroscope's scale factor within the input angular rate range and the consistency of the gyroscope's scale factor across repeated measurements under the same conditions. These two metrics are key performance indicators for gyroscopes. Only by accurately measuring the gyroscope's scale factor can the performance of an AIMG be properly evaluated.

[0003] Atomic interferometer gyroscopes are severely affected by environmental vibration and noise. When mounted on a turntable during phase sweeping, the system's ability to resolve interference fringes is poor, making it impossible to accurately calculate the rotational phase, leading to inaccurate scale factor measurements. A common solution is to combine phase sweeping with vibration compensation using a meter to calculate the rotational phase. However, this approach is complex, and measurement accuracy depends on the effectiveness of the meter's vibration compensation, which cannot guarantee scale factor accuracy.

[0004] Currently, there are two common methods for measuring gyro scale factors: one is to point the gyro reference axis upward and calculate the scale factor using rotational phase information obtained from a turntable at different rotational speeds; the other is to align the gyro reference axis parallel to the horizontal plane, find north, and then use an azimuth turntable to obtain rotational phase information at different azimuth angles to calculate the scale factor. The former method is fast but suffers from low accuracy due to vibration. The latter method requires precise north finding, which takes a long time and is inconvenient to operate. Summary of the Invention

[0005] In view of this, an embodiment of the present invention provides a method and system for testing the scale factor of an atomic interferometer gyroscope, which is used to solve the problems of low accuracy and long operation time in current scale factor testing.

[0006] In a first aspect of an embodiment of the present invention, a method for testing a scale factor of an atomic interferometer gyroscope is provided, comprising:

[0007] Fix the atomic interferometer gyroscope on the turntable so that the reference axis of the atomic interferometer gyroscope points vertically upward to the sky, and power the atomic interferometer gyroscope and the turntable;

[0008] The atomic interferometer gyroscope is started, and the phase of the Raman light DDS generator is obtained when the turntable is stationary, and the phase of the Raman light DDS generator is used as the first output phase of the atomic interferometer gyroscope;

[0009] The turntable is started and controlled to rotate forward and reverse at a given angular velocity, and the second output phase of the atomic interferometer gyroscope after waist-locked phase compensation is performed on the atomic interferometer gyroscope is recorded;

[0010] The waist-locking phase compensation is the phase compensation required to adjust the left and right atomic groups of the gyroscope to work in the middle position of the interference fringes;

[0011] After the test, the third output phase of the atomic interferometer gyroscope when the turntable is stationary is recorded, and the average output of the atomic interferometer gyroscope when the turntable is stationary is calculated based on the first output phase and the third output phase;

[0012] Based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, the atomic gyroscope output at different given angular velocities is calculated, and the corresponding atomic interferometer gyroscope input and output model is constructed;

[0013] The test data of the atomic gyroscope output under different given angular velocities are obtained, and the input and output model of the atomic interferometer gyroscope is solved by least squares fitting to obtain the atomic interferometer gyroscope scale factor.

[0014] In a second aspect of an embodiment of the present invention, a system for testing a scale factor of an atomic interferometer gyroscope is provided, comprising:

[0015] The atomic interferometer gyroscope is used to obtain the phase of the Raman light DDS generator when the turntable is stationary as a first output phase after the gyroscope is started; after the turntable is started, perform waist-locked phase compensation according to computer instructions and obtain a second output phase; after the test is completed, obtain a third output phase when the turntable is stationary; and send the first output phase, the second output phase, and the third output phase to the computer;

[0016] The waist-locking phase compensation is the phase compensation required to adjust the left and right atomic groups of the gyroscope to work in the middle position of the interference fringes;

[0017] A turntable, used for forward and reverse rotation according to an angular velocity given by a computer;

[0018] The atomic interferometer gyroscope is fixed on a turntable, the atomic interferometer gyroscope's rotation reference axis is vertically upward and points to the sky, and the atomic interferometer gyroscope and the turntable are powered;

[0019] The computer is used to control the atomic interferometer gyroscope to perform waist-locked phase compensation, set the angular velocity of the turntable, and receive a first output phase, a second output phase, and a third output phase. The computer calculates the average output of the atomic interferometer gyroscope when the turntable is stationary based on the first output phase and the third output phase. The output of the atomic interferometer gyroscope at different given angular velocities is calculated based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, and a corresponding input-output model of the atomic interferometer gyroscope is constructed. Test data of the atomic gyroscope output at different given angular velocities is obtained. The input-output model of the atomic interferometer gyroscope is solved by least squares fitting to obtain a scale factor of the atomic interferometer gyroscope.

[0020] In an embodiment of the present invention, a waist-locked phase compensation method is adopted to calculate the rotation phase offset, and use it as the phase change value caused by the rotation, thereby solving the scale factor of the gyroscope input and output model. As a result, not only is the ability to resist environmental vibration interference strong, the scale factor test accuracy is high, and compared with the traditional north-seeking azimuth angle measurement scale factor, the measurement speed is fast, the efficiency is high, and the operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 A schematic diagram illustrating the principle of a method for testing the scale factor of an atomic interferometer gyroscope provided by one embodiment of the present invention;

[0023] Figure 2 A schematic flow chart of a method for testing the scale factor of an atomic interferometer gyroscope provided in accordance with one embodiment of the present invention;

[0024] Figure 3 A schematic structural diagram of an atomic interferometer gyroscope scale factor testing system provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] It should be understood that the terms "including" and similar expressions in the specification, claims, and drawings of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, or apparatus comprising a series of steps or units is not limited to the listed steps or units. Furthermore, the terms "first" and "second" are used to distinguish between different objects and are not intended to describe a specific order.

[0027] In one embodiment, the atomic interferometer gyroscope scale factor test principle is as follows: Figure 1 As shown, the test system includes an atomic interferometer gyroscope (AIG), a turntable, a computer, and control cables 1 and 2. The turntable and computer are connected via control cable 1. The turntable serves as the carrier of the AIG, enabling the gyroscope to rotate at different speeds. The AIG and computer are connected via control cable 2, which is fixed to the turntable surface and receives computer commands and outputs rotation information. The computer is used to send commands to control the turntable's rotation, receive rotation information from the AIG, and send commands to implement AIG waist-locked phase compensation to obtain output phase information for scale factor calculation.

[0028] See also Figure 2 Another embodiment of the present invention provides a flow chart of a method for testing the scale factor of an atomic interferometer gyroscope, including:

[0029] S201, fixing the atomic interferometer gyroscope on a turntable so that the atomic interferometer gyroscope's rotation reference axis points vertically upward to the sky, and energizing the atomic interferometer gyroscope and the turntable;

[0030] The atomic interferometer gyroscope (AIG) is a gyroscope based on the principle of atomic interference and is generally used to measure angular velocity. It works by cooling atoms to near absolute zero, causing them to form matter waves. When these atoms propagate in opposite directions along a circular optical path, the Sagnac effect caused by the rotation causes the optical path lengths of the two matter waves to differ, resulting in a phase difference. Angular velocity can be calculated from this phase difference.

[0031] The turntable is a platform that is controlled by a computer and rotates in a forward or reverse direction at a set angular velocity. The atomic interferometer gyroscope is fixed to the turntable so that the atomic interferometer gyroscope rotates with the turntable at a fixed angular velocity.

[0032] The atomic interferometer gyroscope's rotation reference axis points vertically upward to the sky, indicating that it points in the direction opposite to gravity, that is, the sky in the northeast celestial coordinate system (station center coordinate system).

[0033] S202, starting the atomic interferometer gyroscope, obtaining the phase of the Raman light DDS generator when the turntable is stationary, and using the phase of the Raman light DDS generator as the first output phase of the atomic interferometer gyroscope;

[0034] The Raman optical DDS (Direct Digital Synthesis) generator is a Raman optical signal generator, which modulates the signal source signal and changes the phase of the Raman light by controlling the radio frequency signal of the Raman light.

[0035] S203, starting the turntable, controlling the turntable to rotate forward and reverse at a given angular velocity, and recording the second output phase of the atomic interferometer gyroscope after performing waist-locked phase compensation on the atomic interferometer gyroscope;

[0036] The waist-locking phase compensation is the phase compensation required to adjust the left and right atomic groups of the gyroscope to work in the middle position of the interference fringes;

[0037] The atomic interferometer gyroscope is a three-pulse interferometer gyroscope, that is, a three-Raman pulse gyroscope.

[0038] It can be understood that the atomic interference signal of the atomic interferometer gyroscope satisfies the following formula:

[0039] ;

[0040] At small angles:

[0041]

[0042]

[0043]

[0044] Combining the above two equations, the phase It can be expressed as:

[0045]

[0046] For the two atoms on the left and right with opposite effective wave vectors, , A simple calculation can be performed to obtain the rotation phase :

[0047] =

[0048] When the atomic interference gyroscope is placed on the turntable, the left and right atomic groups are adjusted to work at the waist of the interference fringes. When the turntable is stationary, the rotation phase of the solution is is a fixed value, which can be used as the output of the atomic interferometer gyroscope when it is stationary. When the speed of rotation is will change, and the amount of change is Phase output of atomic interferometer gyroscope under rotation speed.

[0049] Optionally, the phase of the single Raman light DDS generator during the atomic group interference process is controlled by a PID algorithm, so that the left and right atomic groups of the atomic interference gyroscope work at the middle position of the interference fringes without changing.

[0050] The PID algorithm is used to control the phase of the single Raman light DDS in the process of atomic group interference, and the phase change caused by the rotation of the turntable is compensated, so that the atomic groups on the left and right of the atomic interference gyroscope are calculated by the formula In this case, the change in the DDS phase can be equated to the atomic interferometer gyro rotation phase caused by the turntable rotation. Finally, the atomic interferometer gyro scale factor can be calculated by calculating the DDS phase output by the atomic interferometer gyro.

[0051] S204, after the test is completed, recording the third output phase of the atomic interferometer gyroscope when the turntable is stationary, and calculating the average output of the atomic interferometer gyroscope when the turntable is stationary based on the first output phase and the third output phase;

[0052] Among them, after the test, the output phase of the atomic interferometer gyroscope is recorded when the turntable is stationary. , that is, the third output phase, combined with the Raman DDS phase recorded at the beginning of the test when the turntable was stationary , that is, the first output phase, according to formula (1), the average phase value of the atomic interferometer gyroscope output when the turntable is stationary is obtained:

[0053] ;(1)

[0054] Where, represents the average output of the atomic interferometer gyroscope when the turntable is stationary, represents the first output phase, Indicates the third output phase.

[0055] S205, calculating the atomic gyroscope output at different given angular velocities based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, and constructing a corresponding atomic interferometer gyroscope input and output model;

[0056] Specifically, the output of the atomic gyroscope at different given angular velocities is calculated according to formula (2):

[0057] - ; (2)

[0058] Where, Indicates the nth given angular velocity The output of the atomic gyroscope, represents the second output phase of the atomic interferometer gyroscope under phase compensation, represents the average output of the atomic interferometer gyroscope when the turntable is stationary;

[0059] The input and output model of the constructed atomic interferometer gyroscope is expressed as:

[0060] ; (3)

[0061] Where K represents the scale factor of the atomic gyroscope, represents the angular velocity of the turntable, Indicates the fitting zero.

[0062] S206 , obtaining test data of the atomic gyroscope output under different given angular velocities, solving the atomic interferometer gyroscope input and output model by least square fitting, and obtaining the atomic interferometer gyroscope scale factor.

[0063] Based on multiple sets of test data, the least squares method is used to fit the straight line and the scale factor K of the atomic interferometer gyroscope is calculated.

[0064] In this embodiment, the atomic interferometer gyroscope is subjected to a waist-locked phase compensation method to calculate the rotational phase offset, which is used as the phase change value of the atomic interferometer gyroscope caused by the rotation of the turntable. The atomic interferometer gyroscope scale factor is then calculated in combination with the test data. This method not only has strong resistance to environmental vibration interference and high accuracy, but also has fast and efficient scale factor measurement speed.

[0065] It should be understood that the sequence numbers of the steps in the above embodiments do not imply a specific order of execution; the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0066] Figure 3 A schematic structural diagram of an atomic interferometer gyroscope scale factor test system provided in an embodiment of the present invention, the system comprising:

[0067] The atomic interferometer gyroscope 310 is configured to obtain, after the gyroscope is started, the phase of the Raman light DDS generator when the turntable is stationary as a first output phase; after the turntable is started, perform waist-locking phase compensation according to computer instructions and obtain a second output phase; after the test is completed, obtain a third output phase when the turntable is stationary; and transmit the first output phase, the second output phase, and the third output phase to the computer 330;

[0068] The waist-locking phase compensation is the phase compensation required to adjust the left and right atomic groups of the gyroscope to work in the middle position of the interference fringes;

[0069] The turntable 320 is used to rotate in the forward and reverse directions according to the angular velocity given by the computer 330;

[0070] The atomic interferometer gyroscope 310 is fixed on the turntable 320, and the reference axis of the atomic interferometer gyroscope 310 is vertically upward and points to the sky. The atomic interferometer gyroscope 310 and the turntable 320 are powered.

[0071] Computer 330 is used to control the atomic interferometer gyroscope 310 to perform waist-locked phase compensation, set the angular velocity of the turntable 320, and receive the first output phase, the second output phase, and the third output phase. According to the first output phase and the third output phase, the average output of the atomic interferometer gyroscope when the turntable is stationary is calculated. Based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, the output of the atomic gyroscope at different given angular velocities is calculated, and a corresponding input-output model of the atomic interferometer gyroscope is constructed to obtain test data of the atomic gyroscope output at different given angular velocities. The input-output model of the atomic interferometer gyroscope is solved by least squares fitting to obtain a scale factor of the atomic interferometer gyroscope.

[0072] The atomic interferometer gyroscope 310 is a three-pulse interferometer gyroscope.

[0073] Specifically, the atomic interferometer gyroscope lock waist phase compensation includes:

[0074] The phase of the single Raman light DDS generator in the atomic group interference process is controlled by PID algorithm, so that the left and right atomic groups of the atomic interferometer gyroscope work in the middle position of the interference fringes.

[0075] The average output value of the atomic interferometer gyroscope when the turntable is stationary is calculated according to formula (1):

[0076] ;(1)

[0077] Where, represents the average output of the atomic interferometer gyroscope when the turntable is stationary, represents the first output phase, Indicates the third output phase.

[0078] Among them, the output of the atomic gyroscope at different given angular velocities is calculated according to formula (2):

[0079] - ; (2)

[0080] Where, Indicates the nth given angular velocity The output of the atomic gyroscope, represents the second output phase of the atomic interferometer gyroscope under phase compensation, represents the average output of the atomic interferometer gyroscope when the turntable is stationary;

[0081] The input and output model of the constructed atomic interferometer gyroscope is expressed as:

[0082] ; (3)

[0083] Where K represents the scale factor of the atomic gyroscope, represents the angular velocity of the turntable, Indicates the fitting zero.

[0084] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, devices, and modules can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0085] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0086] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the scale factor of an atomic interferometer gyroscope, characterized in that: include: Fix the atomic interferometer gyroscope on the turntable so that the reference axis of the atomic interferometer gyroscope points vertically upward to the sky, and power the atomic interferometer gyroscope and the turntable; The atomic interferometer gyroscope is started, and the phase of the Raman light DDS generator is obtained when the turntable is stationary, and the phase of the Raman light DDS generator is used as the first output phase of the atomic interferometer gyroscope; The turntable is started and controlled to rotate forward and reverse at a given angular velocity, and the second output phase of the atomic interferometer gyroscope after waist-locked phase compensation is performed on the atomic interferometer gyroscope is recorded; The waist-locking phase compensation is the phase compensation required to adjust the left and right atomic groups of the gyroscope to work in the middle position of the interference fringes; After the test, the third output phase of the atomic interferometer gyroscope when the turntable is stationary is recorded, and the average output of the atomic interferometer gyroscope when the turntable is stationary is calculated based on the first output phase and the third output phase; Based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, the atomic gyroscope output at different given angular velocities is calculated, and the corresponding atomic interferometer gyroscope input and output model is constructed; The test data of the atomic gyroscope output under different given angular velocities are obtained, and the input and output model of the atomic interferometer gyroscope is solved by least squares fitting to obtain the atomic interferometer gyroscope scale factor.

2. The method according to claim 1, characterized in that The atomic interferometer gyroscope is a three-pulse counter-throw type.

3. The method according to claim 1, characterized in that The control turntable rotates forward and reverse at a given angular velocity respectively, and recording the second output phase of the atomic interferometer gyroscope after performing waist-locked phase compensation on the atomic interferometer gyroscope comprises: The phase of the single Raman light DDS generator in the atomic interferometer gyroscope atomic cluster interference process is controlled by PID algorithm, so that the left and right atomic clusters of the atomic interferometer gyroscope work in the middle position of the interference fringes.

4. The method according to claim 1, wherein The calculation of the output average value of the atomic interferometer gyroscope when the turntable is stationary according to the first output phase and the third output phase comprises: According to formula (1), the average output of the atomic interferometer gyroscope when the turntable is stationary is calculated: ;（1） Where, represents the average output of the atomic interferometer gyroscope when the turntable is stationary, represents the first output phase, Indicates the third output phase.

5. The method according to claim 1, wherein The calculation of the atomic gyroscope output at different given angular velocities based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, and the construction of the corresponding atomic interferometer gyroscope input and output model include: According to formula (2), the output of the atomic gyroscope at different given angular velocities is calculated: - ；（2） Where, Indicates the nth given angular velocity The output of the atomic gyroscope, represents the second output phase of the atomic interferometer gyroscope under phase compensation, represents the average output of the atomic interferometer gyroscope when the turntable is stationary; The input and output model of the constructed atomic interferometer gyroscope is expressed as: ；（3） Where K represents the scale factor of the atomic gyroscope, represents the angular velocity of the turntable, Indicates the fitting zero.

6. An atomic interferometer gyroscope scale factor test system, characterized in that: include: The atomic interferometer gyroscope is used to obtain the phase of the Raman light DDS generator when the turntable is stationary as a first output phase after the gyroscope is started; after the turntable is started, perform waist-locked phase compensation according to computer instructions and obtain a second output phase; after the test is completed, obtain a third output phase when the turntable is stationary; and send the first output phase, the second output phase, and the third output phase to the computer; The waist-locking phase compensation is the phase compensation required to adjust the left and right atomic groups of the gyroscope to work in the middle position of the interference fringes; A turntable, used for forward and reverse rotation according to an angular velocity given by a computer; The atomic interferometer gyroscope is fixed on a turntable, the atomic interferometer gyroscope's rotation reference axis is vertically upward and points to the sky, and the atomic interferometer gyroscope and the turntable are powered; The computer is used to control the atomic interferometer gyroscope to perform waist-locked phase compensation, set the turntable angular velocity, and receive a first output phase, a second output phase, and a third output phase. The computer calculates an average output of the atomic interferometer gyroscope when the turntable is stationary based on the first output phase and the third output phase. The output of the atomic interferometer gyroscope at different given angular velocities is calculated based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, and a corresponding input-output model of the atomic interferometer gyroscope is constructed. Test data of the atomic gyroscope output at different given angular velocities is obtained. The input-output model of the atomic interferometer gyroscope is solved by least squares fitting to obtain a scale factor of the atomic interferometer gyroscope.

7. The system according to claim 6, characterized in that The atomic interferometer gyroscope is a three-pulse counter-throw type.

8. The system according to claim 6, wherein: The atomic interferometer gyroscope waist-locking phase compensation comprises: The phase of the single Raman light DDS generator in the atomic interferometer gyroscope atomic cluster interference process is controlled by PID algorithm, so that the left and right atomic clusters of the atomic interferometer gyroscope work in the middle position of the interference fringes.

9. The system according to claim 6, wherein: The calculation of the output average value of the atomic interferometer gyroscope when the turntable is stationary according to the first output phase and the third output phase comprises: According to formula (1), the average output of the atomic interferometer gyroscope when the turntable is stationary is calculated: ;（1） Where, represents the average output of the atomic interferometer gyroscope when the turntable is stationary, represents the first output phase, Indicates the third output phase.

10. The system according to claim 6, wherein: The calculation of the atomic gyroscope output at different given angular velocities based on the second output phase and the average output of the atomic interferometer gyroscope when the turntable is stationary, and the construction of the corresponding atomic interferometer gyroscope input and output model include: According to formula (2), the output of the atomic gyroscope at different given angular velocities is calculated: - ；（2） Where, Indicates the nth given angular velocity The output of the atomic gyroscope, represents the second output phase of the atomic interferometer gyroscope under phase compensation, represents the average output of the atomic interferometer gyroscope when the turntable is stationary; The input and output model of the constructed atomic interferometer gyroscope is expressed as: ；（3） Where K represents the scale factor of the atomic gyroscope, represents the angular velocity of the turntable, Indicates the fitting zero.

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