A range extension system and method for a cold atom interferometric gyroscope

Abstract

The present application relates to a kind of range extension system and method of cold atom interference gyro, utilize the output information of cold atom interference gyro and optical gyro, the maximum likelihood method is used to estimate the extension period number of cold atom interference gyro phase, the extension period number is fused with the output of cold atom interference gyro, obtain two cold atom interference gyro extension output value, the obtained two cold atom interference gyro extension output value is compared with optical gyro output value, with the absolute value minimum of difference value as judging basis, only uniqueness is judged, obtain final angular velocity.The present application fuses the advantages of cold atom interference gyro and optical gyro, solves the contradiction of large range and high resolution of angular velocity measurement, can realize angular velocity large range and high resolution measurement.Simultaneously, since the dynamic measurement range is small, the problem that cold atom interference gyro cannot be used for inertial navigation is solved, and a technical foundation for cold atom interference gyro used for inertial navigation is laid.

Description

Technical Field

[0001] This invention belongs to the field of inertial measurement technology, and in particular to a range extension system and method for a cold atom interferometric gyroscope. Background Technology

[0002] The working principle of a cold atom interferometric gyroscope is to separate a cluster of cold atoms into two freely flying, spatially separated clusters. The change in the vertical displacement of the atomic motion direction over time is used to simulate the two paths of the interferometer. Typically, a laser pulse with a resonant frequency to the distance between the atomic ground state energy levels is used to manipulate the clusters, causing them to separate, reflect, and combine to form a closed interference loop with a certain area. When the cold atom interferometric gyroscope is subjected to the rotation of an external carrier, a phase difference exists between the two clusters that have followed different paths. By collecting the number of atoms at each detection port, the rotation information can be calculated.

[0003] Cold atom interferometric gyroscopes, as a new generation of angular velocity measurement sensors, possess the potential for ultra-high precision, bringing new opportunities for improving the accuracy of inertial navigation systems. Cold atom interferometric gyroscopes exhibit good zero-bias stability and repeatability, and possess extremely high expected accuracy. However, currently, all cold atom interferometric gyroscopes operate in an open-loop state, with a small dynamic measurement range, preventing direct application to inertial navigation systems. Therefore, extending the dynamic range of cold atom interferometric gyroscopes is a key technology for realizing inertial navigation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and propose a range extension system and method for a cold atom interferometric gyroscope. This system can estimate the number of extended phase periods of the cold atom interferometric gyroscope using the output information of the cold atom interferometric gyroscope and the optical gyroscope, fuse the number of extended phase periods with the output of the cold atom interferometric gyroscope, and determine the uniqueness of the output based on the output of the optical gyroscope to obtain the dynamic extended output of the cold atom interferometric gyroscope.

[0005] The technical problem solved by this invention is achieved through the following technical solution:

[0006] A range extension system for a cold atom interferometric gyroscope includes a cold atom interferometric gyroscope, an optical gyroscope, a phase extension period number estimation module, a data fusion module, and a data uniqueness determination module. The input terminals of the cold atom interferometric gyroscope and the optical gyroscope respectively input angular velocities. The output terminals of the cold atom interferometric gyroscope and the optical gyroscope are connected to the input terminal of the phase extension period number estimation module. The phase extension period number estimation module, the data fusion module, and the data uniqueness determination module are connected in series. The output terminal of the cold atom interferometric gyroscope is connected to the input terminal of the data fusion module, and the output terminal of the optical gyroscope is connected to the input terminal of the data uniqueness determination module. The output terminal of the data uniqueness determination module outputs the final angular velocity.

[0007] Furthermore, the input axes of the cold atom interferometer gyroscope and the optical gyroscope are coaxially mounted.

[0008] A method for range extension of a cold atom interferometric gyroscope range extension system includes the following steps:

[0009] Step 1: Set the angular velocity ω in The inputs are respectively fed to the input terminals of the cold atom interferometer gyroscope and the optical gyroscope;

[0010] Step 2: The cold atom interferometer gyroscope measures the angular velocity of the sensitive carrier and outputs the atomic layout number S. a The optical gyroscope measures the angular velocity of the sensitive carrier and outputs the angular velocity ω. o ;

[0011] Step 3: The phase expansion period number estimation module estimates the atomic layout number S based on the output of the cold atom interferometer gyroscope. a And the optical gyroscope 3 outputs angular velocity ω o The maximum likelihood method was used to estimate the possible number of phase spread periods of the cold atom interferometric gyroscope. and

[0012] Step 4: The data fusion module will merge the atomic layout number S a and phase expansion period number and the Lord The possible output angular velocity is obtained through fusion calculation. and

[0013] Step 5: The data uniqueness determination module determines the uniqueness of the data based on the output ω of the optical gyroscope. o For output angular velocity and Perform a uniqueness check and output the final angular velocity.

[0014] Furthermore, in step 2, the angular velocity of the cold atom interferometric gyroscope sensitive carrier outputs the atomic layout number S. a The specific implementation method is as follows:

[0015]

[0016] Where N is the total number of atoms participating in the interference, C is the contrast of the interference fringes, and k eff =4π / λ is the effective wave vector, λ is the wavelength of the Raman laser, π is the constant of pi, g is the local gravitational acceleration, T is half of the total interference time, and φ0 is the initial phase.

[0017] Furthermore, the specific implementation method of step 3 is as follows:

[0018]

[0019] Where N is the total number of atoms participating in the interference, C is the contrast of the interference fringes, and k eff =4π / λ is the effective wave vector, λ is the wavelength of the Raman laser, π is the constant of pi, g is the local gravitational acceleration, T is half of the total interference time, and φ0 is the initial phase.

[0020] Moreover, the specific implementation method of step 4 is as follows:

[0021]

[0022] Where N is the total number of atoms participating in the interference, C is the contrast of the interference fringes, and k eff =4π / λ is the effective wave vector, λ is the wavelength of the Raman laser, π is the constant of pi, g is the local gravitational acceleration, T is half of the total interference time, and φ0 is the initial phase.

[0023] Furthermore, the specific implementation method of step 5 is as follows:

[0024] Determine if δ1≤δ2. If δ1≤δ2, then output the cold atom interferometer gyroscope. Otherwise, the cold atom interferometer gyroscope output .

[0025] The advantages and positive effects of this invention are:

[0026] This invention utilizes the output information of cold atom interferometric gyroscopes and optical gyroscopes. It employs the maximum likelihood method to estimate the number of extended periods of the cold atom interferometric gyroscope phase. This extended period number is then fused with the cold atom interferometric gyroscope output to obtain two extended output values. These two extended output values ​​are compared with the optical gyroscope output value, and the uniqueness is determined by minimizing the absolute value of the difference, thus yielding the final angular velocity. This invention combines the advantages of cold atom interferometric gyroscopes and optical gyroscopes, resolving the contradiction between large range and high resolution in angular velocity measurement, enabling both large range and high resolution measurements. Simultaneously, it addresses the problem that the small dynamic measurement range of cold atom interferometric gyroscopes prevents their use in inertial navigation, laying the technical foundation for their application in inertial navigation. Attached Figure Description

[0027] Figure 1 This is a flowchart of the present invention;

[0028] Figure 2 This is a schematic diagram of the coaxial mounting of the cold atom interferometer gyroscope and the optical gyroscope of the present invention. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings.

[0030] A range extension system for a cold atom interferometric gyroscope, such as Figure 1 As shown, the system includes a cold atom interferometric gyroscope, an optical gyroscope, a phase expansion period estimation module, a data fusion module, and a data uniqueness determination module. The input terminals of the cold atom interferometric gyroscope and the optical gyroscope are respectively connected to the input terminal of the phase expansion period estimation module. The phase expansion period estimation module, the data fusion module, and the data uniqueness determination module are connected in series. The output terminal of the cold atom interferometric gyroscope is connected to the input terminal of the data fusion module, and the output terminal of the optical gyroscope is connected to the input terminal of the data uniqueness determination module. The output terminal of the data uniqueness determination module outputs the final angular velocity.

[0031] like Figure 2 As shown, the input axes of the cold atom interferometer gyroscope and the optical gyroscope are mounted coaxially. OXYZ is an orthogonal rectangular coordinate system, with the Z-axis being the input axis for both the optical gyroscope and the cold atom interferometer gyroscope.

[0032] A method for range extension of a cold atom interferometric gyroscope range extension system includes the following steps:

[0033] Step 1: Set the angular velocity ω in The inputs are respectively fed to the input terminals of the cold atom interferometer gyroscope and the optical gyroscope;

[0034] Step 2: Measure the angular velocity of the sensitive carrier using a cold atom interferometer gyroscope (the same applies below), and output the atomic layout number S. a The optical gyroscope measures the angular velocity of the sensitive carrier and outputs the angular velocity ω. o .

[0035] The cold atom interferometer gyroscope's sensitive carrier angular velocity outputs the atomic layout number S. a The specific implementation method is as follows:

[0036]

[0037] Where N is the total number of atoms participating in the interference, C is the contrast of the interference fringes, and k eff =4π / λ is the effective wave vector, λ is the wavelength of the Raman laser, π is the constant of pi, g is the local gravitational acceleration, T is half of the total interference time, and φ0 is the initial phase.

[0038] Based on the number of atomic layout S output by the cold atom interferometer gyroscope a The relationship with the input angular velocity is ω in The formula shows that the number of atoms in a layout, S a For multiple possible angular velocity input values ​​(n = 0, 1...):

[0039]

[0040] Therefore, we get:

[0041]

[0042] or

[0043]

[0044] Step 3: The phase expansion period number estimation module estimates the atomic layout number S based on the output of the cold atom interferometer gyroscope. a And the optical gyroscope 3 outputs angular velocity ω o The maximum likelihood method was used to estimate the possible number of phase spread periods of the cold atom interferometric gyroscope. and

[0045]

[0046] Step 4: The data fusion module will merge the atomic layout number S a and phase expansion period number and the Lord The possible output angular velocity is obtained through fusion calculation. and

[0047]

[0048] Step 5: The data uniqueness determination module determines the uniqueness of the data based on the output ω of the optical gyroscope. o For output angular velocity and Perform a uniqueness check and output the final angular velocity.

[0049]

[0050] Determine if δ1≤δ2. If δ1≤δ2, then output the cold atom interferometer gyroscope. Otherwise, the cold atom interferometer gyroscope output .

[0051] It should be emphasized that the embodiments described in this invention are illustrative rather than limiting. Therefore, this invention includes, but is not limited to, the embodiments described in the specific implementation. Any other implementations derived by those skilled in the art based on the technical solutions of this invention are also within the scope of protection of this invention.

Claims

1. A method for range extension of a cold atom interferometric gyroscope range extension system, characterized in that: The range extension system includes a cold atom interferometric gyroscope, an optical gyroscope, a phase extension period estimation module, a data fusion module, and a data uniqueness determination module. The input terminals of the cold atom interferometric gyroscope and the optical gyroscope are respectively input to the angular velocity. The output terminals of the cold atom interferometric gyroscope and the optical gyroscope are connected to the input terminal of the phase extension period estimation module. The phase extension period estimation module, the data fusion module, and the data uniqueness determination module are connected in series. The output terminal of the cold atom interferometric gyroscope is connected to the input terminal of the data fusion module, and the output terminal of the optical gyroscope is connected to the input terminal of the data uniqueness determination module. The output terminal of the data uniqueness determination module outputs the final angular velocity. The input axes of the cold atom interferometer gyroscope and the optical gyroscope are mounted coaxially. The range extension method includes the following steps: Step 1: Angular velocity The inputs are respectively fed to the input terminals of the cold atom interferometer gyroscope and the optical gyroscope; Step 2: The cold atom interferometer gyroscope measures the angular velocity of the sensitive carrier and outputs the atomic layout number. The optical gyroscope measures the angular velocity of the sensitive carrier and outputs the angular velocity. ; Step 3: The phase expansion period number estimation module estimates the atomic layout number based on the output of the cold atom interferometer gyroscope. and optical gyroscope 3 output angular velocity The maximum likelihood method was used to estimate the number of phase spread periods of the cold atom interferometric gyroscope. and ; Step 4: The data fusion module will combine the atomic layout data. and phase expansion period number and The output angular velocity is obtained through fusion calculation. and ; in, The total number of atoms participating in the interference. To determine the contrast of the interference fringes, For effective wave vector, The wavelength of the Raman laser. Pi is a constant. For the local gravitational acceleration, Half of the total interference time, This is the initial phase; Step 5: The data uniqueness determination module determines the data based on the output of the optical gyroscope. For output angular velocity and Perform a uniqueness check and output the final angular velocity; Determine whether ,like The cold atom interferometer gyroscope outputs... Otherwise, the cold atom interferometer gyroscope output .

2. The range extension method for a range extension system of a cold atom interferometric gyroscope according to claim 1, characterized in that: In step 2, the angular velocity of the cold atom interferometer gyroscope sensitive carrier is used to output the atomic layout number. The specific implementation method is as follows: in, The total number of atoms participating in the interference. To determine the contrast of the interference fringes, For effective wave vector, The wavelength of the Raman laser. Pi is a constant. For the local gravitational acceleration, Half of the total interference time, This is the initial phase.

3. The range extension method for a range extension system of a cold atom interferometric gyroscope according to claim 1, characterized in that: The specific implementation method of step 3 is as follows: in, The total number of atoms participating in the interference. To determine the contrast of the interference fringes, For effective wave vector, The wavelength of the Raman laser. Pi is a constant. For the local gravitational acceleration, Half of the total interference time, This is the initial phase.

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