Closed-loop inertial measurement method, system and equipment based on atom interference and medium

Abstract

The invention provides a closed-loop inertial measurement method, system and equipment based on atom interference and a medium, and the method comprises the following steps: controlling a pair of opposite emission atom sources to enter an interference region to act with three beams of Raman laser, and applying two-photon detuning frequency to the three beams of Raman laser, the detuning frequency takes active generation of a compensation phase in atomic interference phase shift as a target and is obtained based on closed-loop feedback control modulation, and the compensation phase is used for counteracting the influence of various inertial quantities on the inertial measurement system; after interference is finished, two paths of original interference signals are obtained through measurement; determining an error signal related to each inertia quantity according to the two paths of original interference signals; updating the detuning frequency of the three beams of Raman laser by taking the error signal meeting a preset error condition as a control target, and repeating the steps until the target detuning frequency of the three beams of Raman laser when the control target is reached is determined; and determining values of various inertia quantities according to the target detuning frequency. The dynamic range of atom interference inertial measurement can be expanded, and the scale factor stability can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inertial measurement technology in quantum precision measurement, and in particular to a closed-loop inertial measurement method and system based on atomic interference, equipment and medium. BACKGROUND

[0002] The inertial measurement method based on atomic interference has advantages of high sensitivity, high long-term stability and expandable multi-inertial quantity composite measurement, and is an important quantum inertial measurement method. The core of the inertial measurement method based on atomic interference is to simultaneously and accurately measure the inertial quantity of an object, such as angular velocity or acceleration, by using an atomic interferometer. In recent years, in view of the requirements of inertial applications, angular velocity-acceleration composite measurement units based on atomic interference have been proposed. For example, in a three-pulse Raman-Mach-Zehnder interference configuration, an atomic wave packet interacts with three Raman lasers, is split, reflected and combined in sequence, and then interferes, and the interference phase shift contains information of angular velocity and acceleration. Using a counter-atomic source, two interference phase shifts are obtained in the above process, and the angular velocity and acceleration measurement results are decoupled by solving them simultaneously.

[0003] However, the dynamic range of the inertial measurement method based on atomic interference is limited by the atomic interference phase The periodic ambiguity and the de-coherence caused by the atomic longitudinal velocity distribution are generally low, which seriously limits its practical application in dynamic scenarios. Closed-loop control of inertial quantities is a basic method to overcome the above limitations to expand the dynamic range of inertial sensors. In the current research on closed-loop methods of atomic interference inertial sensors, the closed-loop control of a single inertial quantity (such as angular velocity or acceleration) is generally limited, and the demand for simultaneous decoupling measurement of multiple inertial quantities in atomic interference composite inertial measurement cannot be met. Secondly, the existing closed-loop method has obvious shortcomings: on the one hand, using the atomic interference amplitude signal as the measurement signal does not realize the direct mapping of the inertial measurement and the atomic interference phase shift, making the closed-loop process vulnerable to various amplitude noises and limiting the noise level of the closed-loop inertial sensor. On the other hand, it uses the phase difference of the Raman laser for closed-loop control, which has phase periodic ambiguity, which makes the closed-loop range small and difficult to effectively improve the dynamic range of the sensor. SUMMARY

[0004] The present application provides a closed-loop inertial measurement method, system, device and medium based on atomic interference, which solves the defects of amplitude noise affecting precision and small dynamic range in the prior art, and can significantly improve the precision of the inertial measurement result.

[0005] The present application provides a closed-loop inertial measurement method based on atomic interference, applied to an inertial measurement system, the method comprising: controlling a pair of atomic sources to enter an interference region in the vacuum physical cavity and to interact with three Raman lasers, wherein the three Raman lasers are all applied with a two-photon detuning frequency, the two-photon detuning frequency is obtained based on closed-loop feedback control modulation with a target of actively generating a compensation phase in an atomic interference phase shift, the compensation phase is used to offset the influence of a plurality of inertial quantities on the inertial measurement system; after the interference ends, detecting the energy state distribution of the atoms after the interference to obtain two original interference signals; determining an error signal related to various inertial quantities on the inertial measurement system according to the two original interference signals; updating the two-photon detuning frequency of the three Raman lasers with a control target that the error signal meets a preset error condition, and repeating the above steps until a target detuning frequency of the three Raman lasers is determined when the control target is reached; determining the values of the plurality of inertial quantities on the inertial measurement system according to the target detuning frequency.

[0006] The application also provides a closed-loop inertial measurement system based on atomic interference, comprising a vacuum physical cavity, a control module and a laser module, and two atom source cavities are arranged at both ends inside the vacuum physical cavity; The vacuum physical cavity is used to provide a vacuum environment for the interference of the atomic sources generated by each atom source cavity; The control module is used to control each atomic source to enter an interference region in the vacuum physical cavity and to interact with three Raman lasers, wherein the three Raman lasers are all applied with a two-photon detuning frequency, the two-photon detuning frequency is obtained based on closed-loop feedback control modulation with a target of actively generating a compensation phase in an atomic interference phase shift, the compensation phase is used to offset the influence of a plurality of inertial quantities on the inertial measurement system; after the interference ends, detecting the energy state distribution of the atoms after the interference to obtain two original interference signals; determining an error signal related to various inertial quantities on the inertial measurement system according to the two original interference signals; updating the two-photon detuning frequency of the three Raman lasers with a control target that the error signal meets a preset error condition, and repeating the above steps until a target detuning frequency of the three Raman lasers is determined when the control target is reached; determining the values of the plurality of inertial quantities on the inertial measurement system according to the target detuning frequency. The laser module is used to provide the three Raman lasers for the atomic interference process in the vacuum physical cavity.

[0007] The application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the atomic-interference-based closed-loop inertial measurement method according to any one of the preceding embodiments when executing the computer program.

[0008] The application further provides a non-transitory computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the atomic-interference-based closed-loop inertial measurement method according to any one of the preceding embodiments.

[0009] The atomic-interference-based closed-loop inertial measurement method, system, device and medium provided by the application have at least the following technical effects: First, the problem of amplitude noise affecting precision in the prior art is solved. In the application, the inertial measurement system does not directly use the original and variable fluorescence intensity (amplitude) for feedback control, but a key intermediate processing link is added to extract a more stable and more directly reflecting phase deviation error signal from the original signal. By transferring the basis of closed-loop control from the original and easily disturbed amplitude to the processed and more reliable error signal, the application can effectively isolate the direct influence of various amplitude noises on the closed-loop process, thereby solving the problem that the closed-loop process is easily affected by various amplitude noises when the atomic interference amplitude signal is used as the measurement signal in the prior art, and effectively improving the precision of the measurement result.

[0010] Second, the problem of small dynamic range in the prior art is solved. The application completely converts the physical quantity of closed-loop control from phase (a periodic and ambiguous quantity) to frequency (a quantity that can be adjusted in a large range, continuously and without ambiguity). Since frequency adjustment does not have the "wrap-around" problem of phase, no matter how much compensation is needed, the system can accurately correspond by outputting a large enough target detuning frequency value, and there is no ambiguity range limitation, which fundamentally solves the problem of small dynamic range caused by limited control range and realizes the great expansion of the measurement range. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0012] Figure 1 is a flowchart of an atomic-interference-based closed-loop inertial measurement method according to an embodiment of the application.

[0013] ​Figure 2 is a schematic diagram of an open-loop atomic interferometric inertial measurement method according to an embodiment of the present application.

[0014] Figure 3 is a schematic diagram of a first scheme of an inertial measurement method according to an embodiment of the present application.

[0015] Figure 4 is a schematic diagram of a second scheme of an inertial measurement method according to an embodiment of the present application.

[0016] Figure 5 is a schematic diagram of a three-beam Raman laser interferometric configuration according to an embodiment of the present application.

[0017] Figure 6 is a schematic diagram of another three-beam Raman laser interferometric configuration according to an embodiment of the present application.

[0018] Figure 7 is a schematic diagram of a closed-loop atomic interferometric inertial measurement system according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0020] Some basic concepts involved in the present application will be introduced first below.

[0021] Three-pulse interferometric configuration: a quantum simulation of the "Mach-Zehnder interferometer" in classical optics. First pulse (beam splitter): the first Raman laser pulse is incident on the atomic wave packet, similar to a beam splitter, which precisely divides the atomic wave packet into two halves, one half remains in the original path and state, and the other half undergoes a transition and obtains a momentum, moving along a different path. At this time, the atom is in a quantum superposition state of two different motion states. Second pulse (mirror): after a certain time, the second Raman laser pulse is applied, similar to a mirror, which reverses the momentum of the atomic wave packets on the two paths, so that they fly back to each other. Third pulse (beam combiner): after the same time interval, the third Raman laser pulse identical to the first one is applied, similar to a beam combiner, which allows the atomic wave packets on the two paths to recombine.

[0022] Dynamic range: in inertial measurement, it refers to the maximum range of physical quantities (angular velocity and acceleration) that the sensor can accurately measure.

[0023] Atomic interference phase ambiguity: interference phase with periodicity, measured phase and are indistinguishable. When the acceleration or angular velocity is very large, the resulting real phase change can be far beyond one period.

[0024] Atomic longitudinal velocity distribution induced de-coherence: ideally, all atoms in an atomic wave packet have exactly the same velocity, but in reality, even after laser cooling, there is a small distribution of velocities within the atomic ensemble. In a strong acceleration or rotation environment, the difference in interference path experienced by atoms of different velocities is amplified, leading to a phase inconsistency when they recombine at the end, and a reduced fringe contrast, a blurred or even lost signal. This phenomenon is called de-coherence. Once the signal is lost, the measurement cannot proceed.

[0025] Closed loop: a sensor system generates an internal compensation quantity equivalent to the external quantity to be measured (e.g. angular velocity), which is applied to the atomic interference process, with the goal of canceling the effect of the external inertial quantity, so that the final measured interference phase shift is always kept near zero. At this time, instead of reading the error-prone interference phase, the size of the compensation quantity applied to maintain balance is directly read. This compensation quantity accurately reflects the size of the external inertial quantity. Because the system always works in a stable state near zero phase shift, the above-mentioned phase ambiguity and de-coherence problems are greatly suppressed, so that a higher dynamic external environment can be tolerated, greatly expanding the dynamic range.

[0026] Scale factor: refers to the proportional relationship between the sensor output and the actual input physical quantity (such as acceleration or angular velocity). For example, in open loop mode, the relationship between the atomic interference inertial sensor output phase and angular velocity is: , then is the scale factor of the sensor for angular velocity.

[0027] In order to solve the problems in the prior art, the present application provides a closed loop inertial measurement method based on atomic interference, and the execution subject is an inertial measurement system. Figure 1 is a flowchart of a closed loop inertial measurement method based on atomic interference according to an embodiment of the present application. Referring to Figure 1 , the method of the present application can include the following steps: Step 101, control a pair of counter-propagating atomic sources to enter an interference region and interact with three Raman lasers, wherein the three Raman lasers are all applied with a two-photon detuning frequency, the two-photon detuning frequency is obtained based on closed-loop feedback control modulation aiming at actively generating a compensation phase in atomic interference phase shift, and the compensation phase is used to offset the influence of various inertial quantities on the inertial measurement system.

[0028] In the present application, the inertial measurement system can be used to measure multiple inertial quantities such as acceleration and angular velocity simultaneously, and the inertial quantities to be measured can be set according to actual needs. In order to facilitate the presentation of the scheme of the present application, the inertial quantities in each of the subsequent embodiments are taken as examples of angular velocity and acceleration.

[0029] The purpose of using a pair of counter-propagating atomic sources in the present application is to synchronously construct a pair of interferometers in space, so that the angular velocity and acceleration can be accurately separated from the two atomic interference signals.

[0030] In step 101, the interaction of the atomic source with the three Raman lasers realizes beam splitting, reflection and beam combination of the atomic wave packet in turn. In this process, the inertial measurement system is not passively measured in an open loop, but actively applies a small and controllable offset to the frequency of the Raman laser, i.e. a two-photon detuning frequency.

[0031] The value of the two-photon detuning frequency is calculated and updated in real time by a closed-loop control system according to the measurement error of the last time (which will be described later), and the purpose is to accurately add a compensation phase in the atomic interference phase shift. The size and sign of the compensation phase can be finely controlled, so as to real-time offset the real inertial phase shift caused by the inertial input (such as acceleration and rotation) experienced by the inertial measurement system, and finally control the total measurement error to always meet the preset error condition, thereby realizing stable locking.

[0032] Step 102, after the interference ends, the energy state distribution of the atoms after the interference is detected to obtain two original interference signals.

[0033] After the atomic interference process ends, the population of the quantum state in which the atoms finally exist has completely recorded the phase information caused by the inertial effect. Therefore, a variety of methods (including but not limited to laser spectroscopy technology such as stimulated induced fluorescence method) can be used to detect two atomic interference signals, i.e. original interference signals. The atomic interference signals contain interference phase shifts reflecting inertial information.

[0034] Step 103, according to the two original interference signals, determine the error signals related to various inertial quantities experienced by the inertial measurement system.

[0035] In step 103, error signals related to various inertial quantities, such as error signals related to angular velocity and error signals related to acceleration, are determined according to the two original interference signals in a pre-designed calculation strategy (which will be described later).

[0036] In step 104, the two-photon detuning frequency of the three Raman lasers is updated with the error signals meeting the preset error conditions as the control target, and the above steps are repeated until the target detuning frequency of the three Raman lasers is determined when the control target is reached.

[0037] In step 104, the two-photon detuning frequency of the three Raman lasers is updated with the error signals meeting the preset error conditions as the control target, and the above steps are repeated until the target detuning frequency of the three Raman lasers is determined when the control target is reached.

[0038] In step 105, the values of various inertial quantities to which the inertial measurement system is subjected are determined according to the target detuning frequency.

[0039] In step 105, the values of various inertial quantities to which the inertial measurement system is subjected are determined according to the target detuning frequency.

[0040] In step 105, the values of various inertial quantities to which the inertial measurement system is subjected are determined according to the target detuning frequency. First, the problem of amplitude noise affecting precision in the prior art is solved. In the present application, the inertial measurement system does not directly use the original and variable fluorescence intensity (amplitude) for feedback control, but a key intermediate processing link is added to extract a more stable and more directly reflecting phase deviation error signal from the original signal. By transferring the basis of closed-loop control from the original and easily disturbed amplitude to the processed and more reliable error signal, the present application can effectively isolate the direct influence of various amplitude noises on the closed-loop process, thereby solving the problem that the closed-loop process is easily affected by various amplitude noises when the atomic interference amplitude signal is used as the measurement signal in the prior art, and effectively improving the precision of the measurement result.

[0041] Second, the problem of small dynamic range in the prior art is solved. The present application completely converts the physical quantity of closed-loop control from phase (a periodic and ambiguous quantity) to frequency (a quantity that can be adjusted in a large range, continuously and without ambiguity). Since frequency adjustment does not have the "winding" problem of phase, no matter how much compensation is needed, the system can accurately correspond by outputting a large enough target detuning frequency value, and there is no ambiguity range limitation, which fundamentally solves the problem of small dynamic range caused by limited control range, and realizes the great expansion of the measurement range.

[0042] In combination with the above embodiments, in an implementation, the inertial measurement system is provided with a vacuum physical cavity, a first atomic source cavity for generating a first atomic source, and a second atomic source cavity for generating a second atomic source, and the first atomic source and the second atomic source are respectively arranged at two ends inside the vacuum physical cavity. The interference region is located in the vacuum physical cavity.

[0043] Correspondingly, step 101 can include: Step 1011, using a state preparation laser to prepare the first atomic source and the first atomic source to a ground state energy level, respectively.

[0044] In the present application, assuming that the first atomic source is located on the left side of the vacuum physical cavity, the first atomic source can be prepared to a ground state sub-energy level which is first-order insensitive to external magnetic field fluctuation by using a state preparation laser 1, i.e., to a magnetic insensitive energy level of the ground state Assuming that the second atomic source is located on the right side of the vacuum physical cavity, the second atomic source can be prepared to a ground state sub-energy level which is first-order insensitive to external magnetic field fluctuation by using a state preparation laser 2.

[0045] Step 1012, controlling the two atomic sources obtained after the state preparation laser to enter the interference region and respectively interact with three Raman lasers.

[0046] ​Taking the first atomic source as an example, the first Raman laser pulse illuminates the atomic wave packet, precisely splitting it in two. One half maintains its original path and state, while the other half gains momentum and moves along a different path. After a specific time, a second Raman laser pulse is applied, reversing the momentum of the atomic wave packets on the two paths, causing them to fly towards each other again. After the same time interval, a third Raman laser pulse is applied, causing the atomic wave packets on the two paths to reunite.

[0047] In combination with the above embodiments, in one implementation, step 105 may include: Step 1051: Determine the angular velocity value to which the inertial measurement system is subjected according to the target detuning frequency and the reference value corresponding to the angular velocity.

[0048] In the present application, since the control objective in step 104 is that the error signal satisfies a preset error condition, when the error signal is an error signal related to angular velocity, the preset error condition is that the error signal is always equal to a preset error value 1. In this case, the preset error value 1 is a reference value corresponding to the angular velocity. The preset error value 1 can be set according to actual needs, for example, it can be set to 0.

[0049] Therefore, by executing step 1051 , the angular velocity to which the inertial measurement system is subjected can be determined according to a predetermined formula (to be described later) based on the target detuning frequency and the reference value corresponding to the angular velocity.

[0050] Step 1052: Determine the value of the acceleration applied to the inertial measurement system according to the target detuning frequency and the reference value corresponding to the acceleration.

[0051] Similarly, when the error signal is an acceleration-related error signal, the preset error condition is that the error signal is always equal to the preset error value 2. In this case, the preset error value 2 is a reference value corresponding to the acceleration. The preset error value 2 can be set according to actual needs, for example, it can be set to 0.

[0052] Therefore, by executing step 1052 , the acceleration value of the inertial measurement system can be determined according to a predetermined formula (to be described later) based on the target detuning frequency and the reference value corresponding to the acceleration.

[0053] In this application, by establishing a mapping relationship between the respective feedback quantities and the final results for the two decoupled independent measurement channels of angular velocity and acceleration (i.e., using the corresponding reference values ​​for conversion), this method can achieve synchronous, independent and cross-interference-free solution and output of the two inertial quantities of angular velocity and acceleration within a single sensor, thereby ensuring the accuracy and reliability of the measurement results.

[0054] This application provides two solutions applicable to the above steps 101 to 105.

[0055] In the first scheme, the two-photon detuning frequency of the first beam of Raman laser is determined according to a first frequency parameter, the first frequency parameter being used to update the two-photon detuning frequencies of the first beam of Raman laser and the three beams of Raman laser according to the error signal. The two-photon detuning frequency of the second beam of Raman laser is determined according to a second frequency parameter, the second frequency parameter being used to update the two-photon detuning frequency of the second beam of Raman laser according to the error signal. The two-photon detuning frequency of the third beam of Raman laser is determined according to the two-photon detuning frequency of the first beam of Raman laser.

[0056] The order of the three beams of Raman laser acting on the first atomic source is the first beam of Raman laser, the second beam of Raman laser and the third beam of Raman laser, and the order of the three beams of Raman laser acting on the second atomic source is the third beam of Raman laser, the second beam of Raman laser and the first beam of Raman laser.

[0057] Specifically, let the first basic optical frequency be , the second basic optical frequency be , and the Raman transition resonance frequency be . The and of each of the three beams of Raman laser are the same. The frequency difference between and the difference between the Raman transition resonance frequency is denoted as the two-photon detuning . The specific settings of the two-photon detuning frequencies of the three beams of Raman laser are as follows: The two-photon detuning frequency of the first beam of Raman laser is .

[0058] The two-photon detuning frequency of the second beam of Raman laser is .

[0059] The detuning frequency of the third beam of Raman laser is , that is, the same size as , but opposite in sign.

[0060] wherein is a first frequency parameter, is a second frequency parameter, and the values of the first frequency parameter and the second frequency parameter can be adjusted in the process of updating the detuning frequencies of the Raman laser according to the error signal. The first frequency parameter is used to adjust the two-photon detuning frequencies of the first beam and the third beam of Raman laser, and the second frequency parameter is used to adjust the two-photon detuning frequency of the second beam of Raman laser. The above-mentioned two-photon detuning frequencies are angular frequencies (unit: radian).

[0061] In the second scheme, the two-photon detuning frequency of the first Raman laser is determined according to the first frequency parameter and the third frequency parameter; the two-photon detuning frequency of the second Raman laser is determined according to the second frequency parameter and the third frequency parameter; and the two-photon detuning frequency of the third Raman laser is determined according to the first frequency parameter and the third frequency parameter.

[0062] The third frequency parameter is used to simultaneously update the two-photon detuning frequencies of the first Raman laser, the second Raman laser and the third Raman laser according to the error signal.

[0063] Specifically, the two-photon detuning frequency of the first Raman laser is .

[0064] The two-photon detuning frequency of the second Raman laser is .

[0065] The two-photon detuning frequency of the third Raman laser is .

[0066] The third frequency parameter is used to simultaneously update the two-photon detuning frequencies of the first Raman laser, the second Raman laser and the third Raman laser according to the error signal. The third frequency parameter is used to simultaneously update the two-photon detuning frequencies of the first Raman laser, the second Raman laser and the third Raman laser according to the error signal. The time variable is a phase-continuous synchronous scanning (also known as frequency chirp, hereinafter referred to as The chirp rate is the value of the third frequency parameter. The first frequency parameter is the value of the first frequency parameter. The second frequency parameter is the value of the second frequency parameter, which is the same as defined in the first scheme.

[0067] In the second scheme, the second frequency parameter remains unchanged, and the value of the third frequency parameter can be adjusted in the process of updating the detuning frequency of the Raman laser according to the error signal.

[0068] In actual implementation, the first scheme or the second scheme can be selected according to actual needs, and the present application does not limit this.

[0069] In the present application, whether the first scheme or the second scheme is used, it can be applied to different three-pulse interference configurations, and these three-pulse interference configurations (three-beam Raman laser configurations) include but are not limited to: First, two atomic sources are collinear and three Raman lasers are perpendicular to the atomic source trajectory; Second, three Raman lasers are inclined to the atomic source trajectory; Third, the trajectories of the two atomic sources have an included angle and are symmetrical about the three Raman lasers.

[0070] In combination with the above embodiments, in one implementation, in the case that the plurality of inertial quantities include angular velocity and acceleration, step 103 can include: Step 1031, performing phase demodulation on the two original interference signals respectively to obtain two interference phase shifts.

[0071] In this application, the two original interference signals are and Phase demodulation on can obtain the interference phase shift Phase demodulation on can obtain the interference phase shift The specific formula will be described later.

[0072] Step 1032, determining a first error signal related to angular velocity and a second error signal related to acceleration received by the inertial measurement system according to the two interference phase shifts.

[0073] Specifically, step 1032 can include: Determining the difference and sum of the two interference phase shifts; According to the difference or sum, determining the first error signal related to angular velocity and the second error signal related to acceleration. The specific formula for calculating the first error signal and the second error signal will be described in detail later.

[0074] Correspondingly, step 104 can include: Step 1041, updating the two-photon detuning frequency of the three Raman lasers, with the control target that the first error signal and the second error signal satisfy their respective preset error conditions.

[0075] In this step, according to the satisfaction of the first error signal and the second error signal to their respective preset error conditions, the new two-photon detuning frequency of the three Raman lasers is determined again, and then the above steps 101-104 are repeatedly executed until the target detuning frequency of the three Raman lasers is determined to reach the control target.

[0076] Next, the scheme of the present application will be described in detail in combination with specific examples.

[0077] For easy understanding, first, the open-loop atomic interference inertial measurement method is outlined. Figure 2 is a schematic diagram of an open-loop atomic interference inertial measurement method according to an embodiment of the present application. As shown in Figure 2 , in the vacuum physical cavity, the facing atomic source generates facing moving atomic clouds or continuous atomic beams (denoted as atomic source A and atomic source B) respectively, which are prepared to the ground state magnetic insensitive energy level. Subsequently, atomic source A is sequentially interacted with Raman light 1, Raman light 2, and Raman light 3. Raman light 1-3 contain two frequency components with a frequency difference equal to the Raman transition resonance frequency , which is denoted as two-photon detuning . The wave vectors of the two frequency components are and , which are generally in opposite directions, and the effective wave vector of Raman light is defined as . The effective wave vectors of Raman light 1-3 are generally required to be parallel to each other. By adjusting the light intensity of Raman light or the interaction time of laser and atom, the Rabi phase of the interaction of Raman light with atom can be changed. For a three-pulse Raman-Mach-Zehnder interference, Raman light 1-3 are sequentially set as , and pulses, so that atomic source A is split-beam-reflected-beam combined, wherein the atom has a probability of transitioning to energy level and is detected by detection light 1 to obtain interference signal . In the same way, atomic source B is sequentially interacted with Raman light 3, Raman light 2, and Raman light 1, and the atom transitioning to energy level is detected by detection light 2 to obtain interference signal .

[0078] The angular velocities and accelerations in the sensitive axis direction are expressed as: and (1) wherein is the bias of interference signal , I is the amplitude of interference signal , I is the bias of interference signal , I is the amplitude of interference signal , φ is the inertial phase shift introduced by angular velocity , and φ is the inertial phase shift introduced by acceleration . is the effective wave vector of Raman light, is the atomic motion velocity, is the flight time of the atom between adjacent Raman lights. When the atomic velocity is perpendicular to the effective wave vector of Raman light, wherein d is the distance between adjacent Raman lights, and v is the atomic velocity.​ The non-inertial phase shift introduced for each Raman light initial phase, which is related to the Raman light Initial phase The relationship is . By using The symbol difference in , it can be decoupled and further solved the angular velocity and acceleration.

[0079] On the basis of this principle, the atomic interference inertial measurement method (system simultaneously exists two independent closed loops, one is used for locking the angular velocity, and the other is used for locking the acceleration) based on the interference phase shift regulation and control of the angular velocity and the acceleration double closed loop is proposed, through the feedback control of the three-beam Raman light two-photon detuning frequency (respectively denoted as ), the direct extraction and closed loop control of the interference phase are realized. The target is to directly control and lock the total interference phase, so that it remains a constant value (usually zero). In order to achieve this purpose, two different two-photon detuning settings and control schemes are proposed, which are introduced as follows.

[0080] The first scheme: as shown in Figure 3 , the opposite two-photon detuning frequency is applied on the Raman light 1, 3, and the two-photon detuning frequency is applied on the Raman light 2, that is, the two-photon detuning of the Raman light 1-3 is respectively: , , . Figure 3 The implementation principle diagram of the first scheme in the inertial measurement method of an embodiment of the present application is shown. The above two-photon detuning frequency is an angular frequency (unit: radian). At this time, due to the introduction of the above two-photon detuning frequency, the atomic interference phase shift is modulated: (2) At this time, the interference signals and are: (3) Due to the introduction of the two-photon detuning on the Raman light 2, the interference signal is the cosine fringe with the frequency . The phase solving method is used to directly extract the interference phase, for example, the signals and are demodulated using the signals with the same frequency , and the interference phase shifts and are obtained after low-pass filtering: (4) The average and difference operations are performed on the two interference phase shifts, and the following is obtained: (5) Equation (5) obtains an error signal related to angular velocity only by differencing the two phase signals, in In this equation, the compensation phase is generated by a symmetric reverse adjustment (i.e. , which acts to directly cancel the inertial phase shift introduced by angular velocity (rotation). Thus, this adjustment is specifically used to counteract the rotation effect.

[0081] Equation (5) obtains an error signal related to acceleration by summing the two phase signals, in In this equation, the compensation phase is generated by an independent adjustment (i.e. , which acts to directly cancel the inertial phase shift introduced by acceleration. Thus, this adjustment is specifically used to counteract the acceleration effect.

[0082] Therefore, if the double photon detuning frequencies and are simultaneously closed-loop fed back, respectively, the and can be locked to the set points, which are denoted as and , respectively. At this time, the angular velocity and acceleration measurements can be calculated by and , respectively: (6) i.e. the error preset value 1 in the foregoing, i.e. the error preset value 2 in the foregoing.

[0083] According to equation (5), the above two closed-loop control processes are independent, and thus the simultaneous closed-loop decoupled measurement of angular velocity and acceleration can be achieved. The non-inertial phase shift term can be obtained by calibration. For example, based on equation (6), the value of is determined under the condition that the acceleration is accurately known, using a standard inertial device.

[0084] In equation (6), the scale factor of the closed-loop sensor for angular velocity measurement is , which does not contain the atomic velocity v or the flight time T term, and thus is not sensitive to the atomic velocity fluctuation; the scale factor of the closed-loop sensor for acceleration measurement is , which contains the flight time T term, and thus is first-order sensitive to the atomic velocity fluctuation; and the scale factors of the open-loop sensor for angular velocity measurement and acceleration measurement are and , which are first-order and second-order sensitive to atomic velocity fluctuations, respectively. Therefore, the sensor scale factor after the closed loop is less sensitive to atomic velocity fluctuations, thus improving its scale factor stability.

[0085] The implementation steps of the first scheme are summarized as follows: Step 1: Interference The atomic source is state-prepared and enters the interference region. They interact with three Raman lasers, whose two-photon detuning frequencies are precisely controlled by the previous round of feedback: the first and third beams have the same size but opposite directions of frequency detuning, which are used to compensate for the rotation effect; the second beam has an independent adjustment of the frequency, which is used to compensate for the acceleration effect.

[0086] Step 2: Detection and signal acquisition After the interference, two original interference signals are measured and obtained.

[0087] Step 3: Phase extraction Real-time signal processing is performed on the two original interference signals, and two atomic interference phases are extracted from them through phase extraction techniques including but not limited to quadrature demodulation.

[0088] Step 4: Error signal separation Real-time sum and difference operations are performed on the two interference phases. The average value of the phase is used as an error signal related to only one kind of inertial quantity (such as angular velocity), and the difference value of the phase is used as an error signal related to only another kind of inertial quantity (such as acceleration). This step completely separates the two kinds of inertial effects at the control level.

[0089] Step 5: Feedback control and frequency update The two separated error signals are sent to independent feedback controllers. The controllers compare the error with their set points (e.g. zero), calculate the updated values of the two feedback frequencies required for the next round of measurement to cancel the acceleration and angular velocity, respectively, and apply them to the Raman laser system to form a stable closed loop.

[0090] Step 6: Result calculation and output The final measurement of the sensor is the first frequency parameter and the second frequency parameter continuously output during the closed loop locking. The system directly calculates the accurate values of acceleration and angular velocity, which are linearly proportional to them, and outputs them according to the conversion relationship calibrated in advance.

[0091] The second scheme: As shown in Figure 4 , the two-photon detuning frequencies of Raman light 1-3 are: , , Wherein, is a tunable parameter, is a time variable, i.e. the three Raman light two-photon detuning frequency is phase-continuously and synchronously scanned (chirp rate ). Figure 4 is the implementation schematic of the second scheme of the inertial measurement method according to an embodiment of the present application. In the atomic flight process, the interaction time of the atom with the three Raman lights is Due to the introduction of the above-mentioned two-photon detuning frequency, the atomic interference phase shift is modulated: (7) Similar to the first scheme, due to the introduction of the two-photon detuning on the Raman light 2, the signal is the frequency sine (or) cosine fringe. The phase unwrapping method is used to directly extract the interference phase, and the interference phase shifts and are obtained: (8) The average and difference operations are performed on the two interference phase shifts, and (9) Through the control of the chirp rate and the two-photon detuning frequency , the and can be independently locked to the set points, which are denoted as and . Similarly, i.e. the error preset value 1 in the foregoing, i.e. the error preset value 2 in the foregoing.

[0092] At this time, the angular velocity and acceleration measurement results can be calculated by and respectively: (10) According to formula (9), the above-mentioned two closed-loop control processes are independent, so that the simultaneous closed-loop decoupling measurement of the angular velocity and the acceleration can be realized. Similarly to the first scheme, the non-inertial phase shift term can be obtained through calibration. Since in the second scheme, remains constant, the bias term can also be obtained through theoretical calculation. Similarly, the present scheme also improves the scale factor stability of the sensor. After the closed loop, the scale factors of the sensor with respect to the angular velocity and the acceleration are and They are both insensitive to the atomic velocity fluctuation and have a higher scale factor stability than the open-loop case.

[0093] The implementation steps of the second scheme are summarized as follows: Step 1: Interferometry The atomic beam is generated from an atomic source and enters the interferometer after state preparation. The system applies three frequency-modulated Raman lasers to the atomic ensemble. The key feature is that all three lasers are subjected to a synchronous linear frequency chirp, the rate of which is controlled by the acceleration error signal closed-loop feedback. At the same time, the first and third lasers are also subjected to symmetric reverse frequency detuning, which is used to compensate for the rotation effect, as in the first scheme.

[0094] Steps 2-4 are the same as steps 2-4 in the first scheme.

[0095] Step 5: Feedback locking and frequency updating The two error signals are sent to independent feedback controllers. The control signal generated by the acceleration controller is used to control and update the chirp rate applied to the three lasers; the control signal generated by the angular velocity controller is used to control and update the frequency detuning applied to the first and third Raman lasers. The controller calculates the required update value for the next period and applies it to the laser system, forming a stable closed loop.

[0096] Step 6 is the same as step 6 in the first scheme.

[0097] In this application, the main difference between the second scheme and the first scheme lies in the setting of the three Raman light two-photon detuning frequency and the corresponding acceleration closed-loop method. In the first scheme, the two-photon detuning frequency of the second Raman light is controlled to achieve acceleration closed-loop. In the second scheme, the three Raman lights are subjected to frequency chirp at the same rate, and the frequency is kept constant, while the acceleration closed-loop is mainly achieved by adjusting the chirp rate . In other words, for the angular velocity closed-loop, the two schemes are completely the same, both of which are achieved by controlling the differential detuning of the first and third Raman lights. For the acceleration closed-loop, the two schemes are completely different, the first scheme is achieved by controlling the independent detuning of the second (center) Raman light , and the second scheme is achieved by controlling a common, synchronous frequency chirp rate applied to all three Raman lights, while the detuning of the center pulse remains unchanged. Both of the above schemes can achieve simultaneous closed-loop measurement of the angular velocity and acceleration two-axis inertial quantities, and the relevant personnel can choose according to the actual situation of the system.

[0098] In the above process, through the double closed-loop control of angular velocity and acceleration, the two interference phase shifts and are directly closed to the set point, which overcomes the cross-period ambiguity and de-coherence caused by excessive angular velocity or acceleration input, thereby significantly expanding the dynamic range of inertial measurement.

[0099] In summary, the present application proposes a new closed-loop atomic interference inertial measurement method, which is based on precise regulation of the Raman two-photon detuning frequency and simultaneously closed-loop controls the angular velocity phase shift and the acceleration phase shift, thereby realizing large dynamic range measurement of angular velocity and acceleration, which has important value for promoting the dynamic environment application of atomic interference inertial sensor. Through the first and second schemes provided, the two core problems mentioned in the prior art can be effectively solved: (1) For the amplitude signal problem: neither of the two new schemes relies on the original and easily disturbed interference signal amplitude for closed-loop control, but based on phase extraction technology, the phase carrying inertial information is extracted from the original interference signal, which can ensure that the entire closed-loop control is based on phase information rather than amplitude signals that are easily affected by various noises, thereby effectively improving the closed-loop measurement accuracy.

[0100] (2) For the phase manipulation and small dynamic range problem: both of the two new schemes abandon direct phase manipulation with phase wrapping ambiguity, and use frequency manipulation method to indirectly generate compensation phase by accurately regulating the frequency detuning or frequency chirp rate of Raman light, thereby breaking through the range limitation of traditional phase compensation (i.e., the maximum applied phase cannot exceed 2 periods), and realizing truly large dynamic range measurement.

[0101] In addition, based on the above closed-loop measurement method, the present application proposes a closed-loop atomic interference inertial measurement system, which includes a vacuum physical cavity, a laser device, a control device, etc. The vacuum physical cavity is used to accommodate an atomic source and provide a vacuum environment for subsequent atomic interference, and can have various magnetic shields and devices for generating bias magnetic fields inside or outside; the laser device is used to generate various types of lasers required for atomic interference (including but not limited to cooling laser, state preparation laser, blow-off laser, detection laser and Raman laser, etc.), which are input into the vacuum physical cavity to interact with atoms. The control device can include the collection and processing of interference signals and various electrical, optical, thermal parameters in the system, as well as the control and driving of other devices in the atomic interference system, such as controlling the generation of the atomic source, providing bias magnetic field driving current, controlling the frequency, power, phase of the laser and its output enable, controlling the working time sequence of the system, etc.

[0102] It should be noted that, Figures 3-4The closed-loop measurement method in the above embodiment can be applied to different three-pulse interferometric configurations, and the changes still fall within the protection scope of the present application. For the three different three-pulse interferometric configurations given above, the following three embodiments are given respectively.

[0103] Embodiment 1: For configuration 1, two counter-propagating atomic sources move along the same straight line, and the directions of action of the three Raman lasers are strictly perpendicular to the flight direction of the atomic sources. In this configuration, the angular velocity phase shift is obtained from the differential phase of the two interference phase shifts, and the acceleration phase shift is obtained from the average phase of the two interference phase shifts.

[0104] The vacuum physical cavity has an atomic source cavity, which is filled with single or multiple alkali or alkaline earth metal atoms (including but not limited to sodium, potassium, rubidium, cesium, calcium, strontium, and other elements or isotopes) for generating the atomic source A and the atomic source B required for system operation. The atomic source can be various continuous atomic beams, cold atomic clouds, or other low-temperature condensates (such as Bose-Einstein condensates, etc.). The atomic source can be tightly connected to the vacuum cavity through a vacuum flange. The vacuum physical cavity is used to provide the atomic motion and its interaction with the laser, and its surface can be equipped with various windows for external laser to pass through. The vacuum physical cavity can be maintained at high vacuum by various vacuum pumps. The vacuum physical cavity can be integrated or equipped with various magnetic shielding shells inside or outside to shield the geomagnetic field and other magnetic fields, and various devices can be used to generate a bias magnetic field to provide a quantized axis for the atomic and laser interaction process, including but not limited to permanent magnets or pole rods, etc.

[0105] The laser device is used to generate all the lasers required for atomic interferometric measurement, including but not limited to cooling lasers, state preparation lasers, Raman lasers, detection lasers, and possibly push lasers, blow-off lasers, etc. The laser device can have a spatial optical path structure, a fiber optical path structure, or a combination thereof. For easy understanding, one possible way is to use a certain frequency-stabilized laser as a seed source, which is split by a fiber splitter, and then frequency-shifted, modulated, amplified, and frequency-doubled by fiber modulators, amplifiers, and frequency-doubling crystals, etc. to generate fiber outputs of the required frequency and power lasers. They can be connected to a shaping lens barrel composed of spatial optical elements to generate spatial light outputs and enter the vacuum cavity to interact with atoms.

[0106] The control device can include a collection system, a signal conditioning and transmission system, a calculation and program control system, and various signal input and output modules and necessary software and hardware devices. Its functions include but are not limited to: 1) driving various devices or subsystems in the atomic source, the vacuum cavity, and the laser device to work, controlling their working conditions, parameters, and timing; 2) collecting, processing, and calculating atomic interference signals, collecting, processing, and calculating Raman light relative phase signals, and calculating and outputting corresponding control quantities.

[0107] by 87 The system's workflow is illustrated using a continuous-wave Rb atomic beam source as an example. In two opposing atomic source cavities, rubidium atomic chambers are heated to produce atomic vapor. This vapor is then collimated by a mechanical structure and laser to produce a pair of opposing atomic beams with a narrow transverse velocity distribution, which then enter the vacuum chamber.

[0108] First, atomic sources A and B are locked to 87 Rb |5 2 S 1 / 2 , F=2>→|5 2 P 3 / 2 , F=2> (including sideband 87 Rb |5 2 S 1 / 2 , F=1>→|5 2 P 3 / 2 , F=0>) the state preparation laser 1, the state preparation laser 2 of the resonance frequency is prepared to 87 Rb |5 2 S 1 / 2 , F=1>( ) sub-energy level. Subsequently, atomic source 1 interacts with Raman light 1, Raman light 2, and Raman light 3 to form Mach-Zehnder interferometer 1; atomic source 2 interacts with Raman light 3, Raman light 2, and Raman light 1 to form Mach-Zehnder interferometer 2. Raman light 1-3 all contain frequency ,frequency .in: In the above formula, for 87 Rb |5 2 S 1 / 2 , F=1> and 87 Rb|5 2 S 1 / 2 , F=2>the frequency interval between two hyperfine levels; and The two frequency components of the Raman laser can be generated by electro-optical modulator, acousto-optic modulator or injection locking method, or by using the frequency components of the Raman laser. and Taking the electro-optic modulator method as an example, the RF drive modulation frequency Therefore, by changing the frequency of different Raman light driving radio frequency, the above and The numerical value of .

[0109] After the interference zone, the atoms in source A and source B are 87 Rb |5 2 S 1 / 2 , the atoms of F=2> are locked to 87 Rb |5 2 S 1 / 2 , F=2>→|5 2 P 3 / 2 , F=3> resonant frequency detection laser 1, detection laser 2 detection, stimulated emission of fluorescence is collected by the detection device, and an interference signal is obtained and The fluorescence detection device can be a combination of a photodetector and a corresponding lens. and The phase, for example, uses a frequency shift with Raman light 2 The phase-locked frequency is The signal is demodulated to obtain the interference phase shift and : (11) First, the non-inertial phase shift term Calibration: Use a standard inertial input device, such as a high-precision turntable or tilt stage, to Measuring the interferometric phase shift when known and , and solve accordingly Subsequently, closed-loop inertial measurement is performed, including two synchronous closed-loop locking loops of angular velocity and acceleration: (1) Angular velocity closed loop: Use digital or analog methods to obtain the difference between the two interference phase shifts ( :

[0110] To be Taking locking to 0 as an example, in fact, it can be locked to any possible set point. Here is an example of a closed-loop feedback loop: the error signal is obtained by methods including but not limited to analog operation circuits, digital operation circuits or program calculations. , a control signal is generated by the loop controller to feedback control the two-photon detuning frequency of Raman light 1 and 3 The loop controller can be implemented based on analog or digital methods using various control algorithms including proportional-integral-derivative method or Kalman filter. The frequency control method can be implemented using analog voltage-controlled signal source or digital method. When it is locked at 0, the angular velocity closed-loop measurement result can be obtained by calculate:

[0111] (2) Acceleration closed loop: using digital or analog method, the average of two interference phase shifts is calculated :

[0112] Similarly, take it as an example to close it to 0. By including but not limited to analog operation circuit, digital operation circuit or program calculation method to obtain error signal , through the loop controller to generate control signal, feedback control two photon detuning frequency of Raman light 2 . Loop controller can be based on analog or digital method, using a variety of control algorithms including proportional-integral-derivative method or Kalman filter. Frequency control method can use analog voltage controlled signal source, also can adopt digital method to realize. When Locked at 0, the acceleration closed loop measurement result can be calculated by :

[0113] Similarly, the second scheme in this application can also be used for inertial closed loop measurement, and the measurement method and system design have been explained in the foregoing.

[0114] Embodiment 2: for configuration 2, the action direction of three Raman lasers is not perpendicular to the flight direction of the atomic source (that is, there is an inclination angle), and the momentum separation direction of the atomic source is opposite due to the Doppler effect, thereby forming two non-overlapping interference areas in space. In this configuration, the angular velocity phase shift is obtained by the average phase of two interference phase shifts, and the acceleration phase shift is obtained by the differential phase of two interference phase shifts.

[0115] Figure 5 is an implementation schematic diagram of an embodiment of a three-beam Raman laser interference configuration according to an embodiment of the present application. As Figure 5 shown, in some application scenarios, the trajectories of the two atomic beams remain parallel, but the Raman light is not completely perpendicular to the atomic beam. Among the incident Raman light and the reflected Raman light, there are two frequency components (ω1 or ω2) respectively. Due to the introduction of Doppler shift, the effective wave vector directions of the Raman light of the two interferometers are opposite, resulting in opposite momentum separation directions, forming two non-overlapping interference areas, which are different from those in . However, the above first scheme and second scheme are still applicable to the present configuration. Take the first scheme as an example for detailed derivation. At this time, the interference signals and Figures 3-4 are: (16) ​​The non-inertial phase shifts of the two interferometers are denoted as and respectively, and other physical quantities are defined as before. Refer to Example 1, the interference phase shifts and are extracted as: (17) The average and difference operations are performed on the two interference phase shifts, and the results are: (18) As in Example 1, the two-photon detuning frequencies and can still achieve decoupled closed-loop control of and respectively. The difference is that this time is closed-loop angular velocity, and is closed-loop acceleration. According to the method in Example 1, calibrate and , and lock and to the set points, denoted as and . At this time, the angular velocity and acceleration measurement results can be calculated by and respectively: (19) That is, in Example 2, is the error preset value 1 as before, is the error preset value 2 as before.

[0116] The second scheme mentioned above is also applicable to this configuration. Refer to the above process, by controlling the frequency chirp rate and the two-photon detuning frequency , simultaneous closed-loop control of angular velocity and acceleration can be achieved in the configuration shown in Figure 5 . The angular velocity and acceleration measurement results can be calculated by and respectively: (20) Example 3: For configuration 3, as shown in Figure 6 , at this time the two atomic source trajectories do not coincide and are symmetric about the direction of the effective wave vector of the Raman light. The two interferometers have the same direction of the effective wave vector of the Raman light, and the same direction of momentum separation, forming two interference areas with the same direction. The interference phase shift expressions are the same as in Example 1, that is: (21) Therefore, the closed-loop measurement method and system in the embodiment are completely the same as those in Embodiment 1.

[0117] The configuration in Embodiment 3 is completely different from those in Embodiment 1 (overlapping configuration) and Embodiment 2 (non-overlapping configuration with opposite momentum separations). Since the mathematical model (formula 21) describing the system behavior is completely the same as the mathematical model (for example, formula 11) in Embodiment 1, all subsequent signal processing and closed-loop control logic based on the model are also completely the same as those in Embodiment 1.

[0118] As can be seen from Embodiments 2 and 3, by precisely controlling the two-photon detuning frequency of Raman light to precisely control the atomic interference phase shift, the closed-loop decoupled measurement of angular velocity and acceleration based on atomic interference can be realized. In different three-pulse configurations, the signal solving method is different, but it does not affect the applicability of the method. The system proposed in the application is also applicable to the above different configurations.

[0119] The above only gives two variations. Again, it is emphasized that Figures 3-4 The two closed-loop measurement methods in the above embodiments can be applied to different three-pulse interference configurations, and the above examples cannot be regarded as a limitation on the protection scope of the application.

[0120] The application provides a closed-loop atomic interference inertial measurement method, which realizes simultaneous and decoupled closed-loop measurement of angular velocity and acceleration by precisely controlling the two-photon detuning frequency of Raman light. The frequency control method includes two different feasible schemes and is applicable to different atomic interference configurations.

[0121] Meanwhile, the application provides a closed-loop atomic interference inertial measurement system, which includes a vacuum physical cavity, a laser device, and a control device. The measurement method and system will significantly expand the dynamic range of atomic interference inertial measurement and improve its usability in dynamic environments.

[0122] A closed-loop inertial measurement system based on atomic interference provided by the application is described below. The closed-loop inertial measurement system based on atomic interference described below can be correspondingly referred to the closed-loop inertial measurement method based on atomic interference described above. Figure 7 FIG. 1 is a schematic diagram of a closed-loop inertial measurement system based on atomic interference according to an embodiment of the application.

[0123] Referring to Figure 7 The closed-loop atomic interference inertial measurement system of the application includes a vacuum physical cavity, a control module, and a laser module, and two atom source cavities are arranged at the two ends inside the vacuum physical cavity. The vacuum physical cavity is used to provide a vacuum environment for the interference process of the atom source generated by each atom source cavity. The control module is configured to control each of the atomic sources to enter an interference region in the vacuum physical cavity and interact with three Raman lasers, wherein the three Raman lasers are each applied with a two-photon detuning frequency, the two-photon detuning frequency is obtained based on closed-loop feedback control modulation, and the two-photon detuning frequency is used to actively generate a compensation phase in an atomic interference phase, and the compensation phase is used to offset the influence of various inertial quantities on the inertial measurement system; after the interference ends, the energy state distribution of the post-interference atoms is detected to obtain two original interference signals; according to the two original interference signals, an error signal related to various inertial quantities and received by the inertial measurement system is determined; the two-photon detuning frequency of the three Raman lasers is updated until a target detuning frequency of the three Raman lasers is determined when the control target is reached, with the control target being that the error signal satisfies a preset error condition; and the values of the various inertial quantities and received by the inertial measurement system are determined according to the target detuning frequency. The laser module is configured to provide the three Raman lasers for an atomic interference process in the vacuum physical cavity.

[0124] The above description of each module can refer to the foregoing description.

[0125] The application also provides an electronic device, which can include a processor, a communications interface, a memory, and a communications bus, wherein the processor, the communications interface, and the memory complete mutual communication through the communications bus. The processor can invoke a logical instruction in the memory to execute a closed-loop inertial measurement method based on atomic interference.

[0126] In addition, the logical instruction in the memory described above can be implemented in the form of a software functional unit and sold or used as an independent product, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the embodiments of the application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0127] In another aspect, the present application also provides a computer program product, which comprises a computer program, the computer program being stored in a non-transitory computer readable storage medium, and the computer program, when executed by a processor, enables a computer to perform the atomic-interference-based closed-loop inertial measurement method provided by any of the above methods.

[0128] In yet another aspect, the present application also provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program, when executed by a processor, enables a computer to perform the atomic-interference-based closed-loop inertial measurement method provided by any of the above methods.

[0129] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., may be located in one place, or may be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the present embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0130] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus necessary universal hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part that contributes to the prior art, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some part of the embodiments. Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still make modifications to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features thereof; and these modifications or replacements do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A closed-loop inertial measurement method based on atomic interferometry, characterized in that: Applied to an inertial measurement system, the method comprises: Controlling a pair of opposing atomic sources to enter an interference region and interact with three Raman laser beams, wherein the three Raman laser beams are all subjected to a two-photon detuned frequency, wherein the two-photon detuned frequency is modulated based on closed-loop feedback control with the goal of actively generating a compensation phase in the atomic interference phase shift, and the compensation phase is used to offset the influence of multiple inertial quantities on the inertial measurement system; After the interference is completed, the energy state distribution of the atoms after the interference is detected to obtain two original interference signals; determining error signals related to various inertial quantities received by the inertial measurement system based on the two original interference signals; Taking the error signal satisfying a preset error condition as a control target, updating the two-photon detuning frequencies of the three Raman laser beams, and repeating the above steps until determining the target detuning frequencies of the three Raman laser beams when the control target is reached; According to the target detuning frequency, values ​​of the plurality of inertial quantities to which the inertial measurement system is subjected are determined.

2. The closed-loop inertial measurement method based on atomic interferometry according to claim 1, characterized in that: The multiple inertial quantities include angular velocity and acceleration, and determining error signals related to the various inertial quantities received by the inertial measurement system based on the two original interference signals includes: Performing phase calculations on the two original interference signals respectively to obtain two interference phase shifts; determining a first error signal related to angular velocity and a second error signal related to acceleration received by the inertial measurement system according to the two interference phase shifts; The updating of the two-photon detuning frequencies of the three Raman laser beams based on the error signal satisfying a preset error condition as a control target includes: Taking the first error signal and the second error signal satisfying respective corresponding preset error conditions as a control target, the two-photon detuning frequencies of the three Raman laser beams are updated.

3. The closed-loop inertial measurement method based on atomic interferometry according to claim 2, characterized in that: The determining, according to the target detuning frequency, values ​​of the multiple inertial quantities to which the inertial measurement system is subjected includes: determining a value of an angular velocity to which the inertial measurement system is subjected according to the target detuning frequency and a reference value corresponding to the angular velocity; The value of the acceleration applied to the inertial measurement system is determined according to the target detuning frequency and a reference value corresponding to the acceleration.

4. The closed-loop inertial measurement method based on atomic interferometry according to claim 1, characterized in that: The inertial measurement system is provided with a vacuum physical cavity, a first atomic source cavity for generating a first atomic source, and a second atomic source cavity for generating a second atomic source, wherein the first atomic source cavity and the second atomic source cavity are respectively provided at two ends of the vacuum physical cavity, and the interference zone is located in the vacuum physical cavity; The method of controlling a pair of opposing atomic sources to enter the interference region and interact with the three Raman laser beams includes: Using a ground state preparation laser, the first atomic source and the second atomic source are prepared to the ground state energy level respectively; The two atomic sources obtained after the state preparation laser preparation are controlled to enter the interference area in the vacuum physics cavity and interact with the three Raman lasers respectively.

5. The closed-loop inertial measurement method based on atomic interferometry according to claim 4, characterized in that: The three Raman laser beams include a first Raman laser beam, a second Raman laser beam and a third Raman laser beam; The two-photon detuning frequency of the first Raman laser beam is determined according to a first frequency parameter, and the first frequency parameter is used to update the two-photon detuning frequencies of the first Raman laser beam and the three Raman laser beams according to the error signal; The two-photon detuning frequency of the second Raman laser beam is determined according to a second frequency parameter, and the second frequency parameter is used to update the two-photon detuning frequency of the second Raman laser beam according to the error signal; The two-photon detuning frequency of the third Raman laser beam is determined according to the two-photon detuning frequency of the first Raman laser beam; The order in which the three Raman lasers act on the first atom source is the first Raman laser, the second Raman laser and the third Raman laser, and the order in which the three Raman lasers act on the second atom source is the third Raman laser, the second Raman laser and the first Raman laser.

6. The closed-loop inertial measurement method based on atomic interferometry according to claim 5, characterized in that: The two-photon detuning frequency of the first Raman laser beam is determined according to the first frequency parameter and the third frequency parameter; The two-photon detuning frequency of the second Raman laser beam is determined according to the second frequency parameter and the third frequency parameter; The two-photon detuning frequency of the third Raman laser beam is determined according to the first frequency parameter and the third frequency parameter; The third frequency parameter is used to simultaneously update the two-photon detuning frequencies of the first Raman laser beam, the second Raman laser beam, and the third Raman laser beam according to the error signal.

7. The closed-loop inertial measurement method based on atomic interferometry according to claim 2, characterized in that: The determining, based on the two-path interference phase shift, a first error signal related to angular velocity and a second error signal related to acceleration received by the inertial measurement system comprises: Determining the difference and sum of the two interference phase shifts; The first error signal related to the angular velocity and the second error signal related to the acceleration are determined according to the difference or the sum.

8. A closed-loop inertial measurement system based on atomic interferometry, characterized in that: It includes a vacuum physical cavity, a control module and a laser module, wherein an atomic source cavity is provided at each end of the vacuum physical cavity; The vacuum physics cavity is used to provide a vacuum environment for the interference of the atomic sources generated by each of the atomic source cavities; The control module is used to control each of the atomic sources to enter the interference zone in the vacuum physics cavity and interact with the three Raman laser beams, wherein the three Raman laser beams are all applied with a two-photon detuning frequency, and the two-photon detuning frequency is obtained based on closed-loop feedback control modulation with the goal of actively generating a compensation phase in the atomic interference phase shift, and the compensation phase is used to offset the influence of various inertial quantities on the inertial measurement system; after the interference is completed, the energy state distribution of the atoms after the interference is detected to obtain two original interference signals; based on the two original interference signals, the error signals related to various inertial quantities on the inertial measurement system are determined; with the error signal satisfying a preset error condition as the control target, the two-photon detuning frequencies of the three Raman laser beams are updated, and the above steps are repeated until the target detuning frequencies of the three Raman laser beams when the control target is reached are determined; based on the target detuning frequencies, the values ​​of the various inertial quantities on the inertial measurement system are determined; The laser module is used to provide the three Raman laser beams for the atomic interference process in the vacuum physics cavity.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the closed-loop inertial measurement method based on atomic interference according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the closed-loop inertial measurement method based on atomic interferometry according to any one of claims 1 to 7 is implemented.

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