Interference fringe fitting method and interference fringe fitting system for gyroscope of cold atom stem analyzer

Abstract

The invention provides an interference fringe fitting method and system for a cold atom stem instrument gyroscope, and the method comprises the steps: obtaining an interference fringe mathematical model of the cold atom stem instrument gyroscope, and carrying out the linear processing of the interference fringe mathematical model based on a trigonometric function, and obtaining a corresponding linear function; based on the currently sampled horizontal axis fringe phase and atomic transition probability, solving through a least square method to obtain a linear correlation coefficient in a linear function; and expanding the initial phase value range of the fringes, and fitting the interference fringes in the expanded initial phase value range of the fringes based on the linear correlation coefficient, the real-time sampled horizontal axis fringe phase and the atomic transition probability. Through the scheme, the interference fringe fitting precision can be guaranteed, the fitting speed is improved, and the real-time requirement of interference fringe fitting is met.

Description

Technical Field

[0001] The invention belongs to the field of atomic interference gyroscopes, and in particular relates to an interference fringe fitting method and system for a cold atomic interferometer gyroscope. Background Art

[0002] In the past decade, atom interferometry has been rapidly developed and widely used. Due to its high sensitivity and quantum properties, it has potential application prospects in the field of quantum precision measurement. In atomic interferometry experiments, matter wave interference fringes can usually be fitted by modeling. The mathematical model is generally modeled as , is the vertical coordinate of the stripe, indicating the transition probability obtained by detection, Represents the horizontal coordinate of the fringe, that is, the fringe phase.

[0003] Currently, the interference fringe fitting method is based on the observed phase and transition probability Interference fringes fitting can be achieved by using the curve fitting function of the data analysis software, such as Origin or MATLAB. In MATLAB software, the fit function can be called, or tools such as Curve Fitting Toolbox can be used directly. In order to ensure the accuracy of the fitting results, this method generally only analyzes and fits based on the experimental results afterwards, and the real-time performance is poor. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides an interference fringe fitting method and system for a cold atom dry gyroscope, which are used to solve the problem of poor real-time performance of current interference fringe fitting.

[0005] In a first aspect of an embodiment of the present invention, a method for fitting interference fringes of a cold atomic dry gyroscope is provided, comprising: Obtaining a mathematical model of interference fringes of a cold atomic dry instrument gyroscope, and linearizing the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; Based on the current sampled transverse fringe phase and atomic transition probability, the linear correlation coefficient in the linear function is obtained by solving the least square method; The range of fringe initial phase values ​​is expanded, and within the expanded range of fringe initial phase values, the interference fringes are fitted based on the linear correlation coefficient and the real-time sampled transverse axis fringe phase and atomic transition probability.

[0006] In a second aspect of an embodiment of the present invention, an interference fringe fitting system for a cold atom dry gyroscope is provided, comprising: A linearization module is used to obtain a mathematical model of interference fringes of a cold atomic dry instrument gyroscope, and to linearize the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; A coefficient solving module is used to solve the linear correlation coefficient in the linear function by the least square method based on the currently sampled transverse fringe phase and atomic transition probability; The fringe fitting module is used to expand the range of fringe initial phase values. Within the expanded range of fringe initial phase values, the interference fringes are fitted based on the linear correlation coefficient and the real-time sampled transverse axis fringe phase and atomic transition probability.

[0007] In a third aspect of an embodiment of the present invention, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the first aspect of the embodiment of the present invention when executing the computer program.

[0008] In a fourth aspect of an embodiment of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method provided in the first aspect of the embodiment of the present invention are implemented.

[0009] In an embodiment of the present invention, the mathematical model of the interference fringes is converted into corresponding linear functions based on trigonometric functions, and the linear correlation coefficient is solved according to the actual sampling value. The interference fringes are fitted based on the linear correlation coefficient and the expanded initial phase value of the fringe. Therefore, while ensuring the fitting accuracy of the interference fringes of the cold atom dryer gyroscope, the fitting speed is improved and the real-time requirements can be met. The method has the advantages of high fitting accuracy, fast calculation speed, and suitability for embedded real-time computing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 A schematic flow chart of an interference fringe fitting method for a cold atom dry gyroscope provided by an embodiment of the present invention; Figure 2 A schematic diagram of an initial phase distribution provided by an embodiment of the present invention; Figure 3 A schematic structural diagram of an interference fringe fitting system for a cold atom dry gyroscope provided by an embodiment of the present invention; Figure 4 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0012] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0013] It should be understood that the term "including" and other similar expressions in the specification or claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions, such as a process, method, system, or device including a series of steps or units is not limited to the listed steps or units. In addition, "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0014] It can be understood that for typical interference fringes, in atomic gravimeters, the transverse axis phase is generally obtained by scanning the phase, and in atomic gyroscopes or atomic accelerometers, the transverse axis phase is generally obtained by scanning the phase or recording the vibration phase of the interference time period. To fit the interference fringes based on the collected transverse axis phase and transition probability, usually only the curve fitting function provided in the commonly used data analysis software (such as Origin or MATLAB) is required. This method can ensure the accuracy of the fitting results, but it is only suitable for post-data analysis and does not meet the real-time requirements.

[0015] The difficulty of real-time fitting of interference fringes is that the trigonometric functions sin and cos are nonlinear functions and cannot be directly linearly fitted using the least squares method. If the fit function is compiled into a dynamic link library or generated into C code using MATLAB, there are problems such as difficulty in configuring the development environment and slow computing speed, which is not suitable for real-time calculation in embedded processors (such as DSP). In terms of specific computing speed, it has been measured that the time consumed for a single fitting can be as high as 100ms, which is unacceptable for experiments with high data output rates.

[0016] Therefore, it is necessary to design a sin / cos trigonometric function fitting algorithm that can be implemented using C language (or C++ and other languages) to meet the requirements of real-time updating of the interference fringe fitting curve in atomic interference experiments.

[0017] See also Figure 1 , a schematic flow chart of an interference fringe fitting method for a cold atom dry gyroscope provided by an embodiment of the present invention, comprising: S101, obtaining a mathematical model of interference fringes of a cold atomic dry instrument gyroscope, and linearizing the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; The cold atom interferometer gyroscope is a gyroscope that uses the quantum properties of cold atoms to measure rotational angular velocity and linear acceleration. It includes cold atom gyroscopes and cold atom interferometers.

[0018] The mathematical model of interference fringes is generally: Trigonometric functions represent the mapping between a set of arbitrary angles and a set of ratios, including sine, cosine, and tangent functions. Based on the relationship between trigonometric functions, the mathematical model of interference fringes can be transformed and expressed as a linear function.

[0019] Specifically, the interference fringe mathematical model (1) is converted into formula (2) based on trigonometric function conversion: ; (1) Using trigonometric formulas ,have

[0020]

[0021]

[0022] Right now ; (2) definition , , ; The linear function is expressed as: ; (3) Where P represents the transition probability value, P0 represents the fringe bias, and A represents the fringe amplitude. represents the fringe phase, represents the initial phase of the fringe, , , All represent linear correlation coefficients.

[0023] Therefore, the nonlinear function Mathematically transformed into a linear function .

[0024] S102, based on the currently sampled transverse fringe phase and atomic transition probability, solving the linear correlation coefficient in the linear function by the least square method; The horizontal fringe phase can generally be obtained by scanning the phase or recording the vibration phase during the interference period, and the atomic transition probability can be obtained by spectral analysis, that is, measuring the spectral characteristics emitted or absorbed by the transition of atoms between different energy levels to determine the transition probability.

[0025] According to the experimentally collected horizontal fringe phase and transition probability values, a set of equations is constructed, and the linear correlation coefficient in the linear function is obtained by solving it using the least squares method. That is, based on the least squares method, according to the known fringe phase and transition probability , the correlation coefficient in the linear function is obtained by fitting , , The value of .

[0026] Among them, based on the calculated linear correlation coefficient value and the definition of the linear correlation coefficient, the fringe bias, fringe amplitude and fringe initial phase are solved.

[0027] According to the relationship between the linear correlation coefficient and the fringe bias, fringe amplitude and fringe initial phase, that is, , , , and then the fringe offset can be obtained , fringe amplitude and the initial phase of the fringe .

[0028] S103, expanding the range of fringe initial phase values, and fitting the interference fringes based on the linear correlation coefficient and the real-time sampled transverse axis fringe phase and atomic transition probability within the expanded range of fringe initial phase values.

[0029] It can be understood that in the interference phenomenon, the change of the initial phase has an important influence on the formation and distribution of interference fringes. When two coherent waves meet and interfere, their initial phase difference will lead to the appearance of interference fringes. Specifically, the initial phase determines the position of the crest and trough, affecting the distribution of light and dark interference fringes. If the initial phases of the two beams are the same, they will interfere constructively to form bright fringes; if the initial phases differ by half a cycle (i.e. π or 180 degrees), they will interfere destructively to form dark fringes.

[0030] Specifically, according to the linear correlation coefficient and The positive or negative value of the fringe is used to determine the quadrant to which the fringe initial phase belongs. Based on the quadrant to which the fringe initial phase belongs, the range of the fringe initial phase value is expanded to .

[0031] Calculate the initial phase of the fringe The formula is , the effective range of phase is given by decide, and the scope does not exceed (For example, if you use the default C language math library to calculate atan, the output range is ). However, the actual range of the interference phase is determined by arcsin2 , so the linearization process will make the initial phase The effective range is reduced by half.

[0032] Can be based on and The symbol of and The sign of The quadrant to which it should belong, re-extend the phase to , please refer to the following table for details:

[0033] based on and initial phase The quadrant to which it belongs, combined with Figure 2 It can be obtained in Values ​​within the range, Figure 2 Artan is shown in The value within the range, that is, the value within 0-360°.

[0034] In some embodiments, the method proposed in this paper is verified by using the Xilinx Zynq XC7Z020 processor, using the actual received atomic interference experimental data (mainly transition probability, scanning phase parameters and vibration phase data), and implementing the least squares fitting algorithm and fringe fitting program in C language. The experiment shows that the calculation results are accurate and the calculation speed has obvious advantages.

[0035] Specifically, 5-point fitting takes 0.14ms, 8-point fitting takes 0.18ms, 16-point fitting takes 0.27ms, 32-point fitting takes 0.54ms, and 100-point fitting takes 3.46ms. It can be seen that the real-time data update rate requirement of more than 50Hz can be met.

[0036] In this embodiment, the interference fringe mathematical model is linearized and the corresponding linear correlation coefficient is solved by the least square method. The interference fringe is fitted in the expanded fringe initial phase value range by combining the real-time sampling value and the linear correlation coefficient. Not only is the fitting accuracy high and the speed fast, but it can also meet the real-time requirements of embedded devices. It should be understood that the serial numbers of the steps in the above embodiments do not imply a sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0037] Figure 3 A schematic diagram of the structure of an interference fringe fitting system for a cold atom dry gyroscope provided in an embodiment of the present invention, the system comprising: A linearization module 310 is used to obtain a mathematical model of interference fringes of a cold atom dry instrument gyroscope, and linearize the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; Specifically, the interference fringe mathematical model (1) is converted into formula (2) based on trigonometric function conversion: ; (1) ; (2) definition , , ; The linear function is expressed as: ; (3) In the formula, P represents the atomic transition probability value, P0 represents the fringe bias, and A represents the fringe amplitude. represents the horizontal fringe phase, represents the initial phase of the fringe, , , All represent linear correlation coefficients.

[0038] The coefficient solving module 320 is used to solve the linear correlation coefficient in the linear function by the least square method based on the transverse fringe phase and atomic transition probability of the current sampling; Among them, based on the calculated linear correlation coefficient value and the definition of the linear correlation coefficient, the fringe bias, fringe amplitude and fringe initial phase are solved.

[0039] The fringe fitting module 330 is used to expand the range of fringe initial phase values, and fit the interference fringes based on the linear correlation coefficient and the real-time sampled horizontal axis fringe phase and atomic transition probability within the expanded range of fringe initial phase values.

[0040] The range of the initial phase value of the extended fringe includes: According to the linear correlation coefficient and The positive or negative value of the fringe is used to determine the quadrant to which the fringe initial phase belongs. Based on the quadrant to which the fringe initial phase belongs, the range of the fringe initial phase value is expanded to .

[0041] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems and modules can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0042] Figure 4 FIG. 1 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device is used for interference fringe fitting. Figure 4 As shown, the electronic device 4 of this embodiment includes: a memory 410, a processor 420 and a system bus 430, wherein the memory 410 includes an executable program 4101 stored thereon, and those skilled in the art can understand that Figure 4 The electronic device structure shown in the figure does not constitute a limitation of the electronic device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0043] Combine the following Figure 4 A detailed introduction to the various components of electronic equipment: The memory 410 can be used to store software programs and modules. The processor 420 executes various functional applications and data processing of the electronic device by running the software programs and modules stored in the memory 410. The memory 410 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area may store data created according to the use of the electronic device (such as cache data), etc. In addition, the memory 410 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0044] The memory 410 includes an executable program 4101 of the network request method, and the executable program 4101 can be divided into one or more modules / units, which are stored in the memory 410 and executed by the processor 420 to achieve real-time interference fringe fitting, etc. The one or more modules / units can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program 4101 in the electronic device 4. For example, the computer program 4101 can be divided into functional modules such as a linearization module, a coefficient solution module, and a fringe fitting module.

[0045] The processor 420 is the control center of the electronic device. It uses various interfaces and lines to connect various parts of the entire electronic device. It executes various functions of the electronic device and processes data by running or executing software programs and / or modules stored in the memory 410, and calling data stored in the memory 410, so as to monitor the overall status of the electronic device. Optionally, the processor 420 may include one or more processing units; preferably, the processor 420 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, application programs, etc., and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 420.

[0046] The system bus 430 is used to connect the various functional components inside the computer, and can transmit data information, address information, and control information. Its types can be, for example, PCI bus, ISA bus, CAN bus, etc. The instructions of the processor 420 are transmitted to the memory 410 through the bus, and the memory 410 feeds back data to the processor 420. The system bus 430 is responsible for the data and instruction exchange between the processor 420 and the memory 410. Of course, the system bus 430 can also be connected to other devices, such as network interfaces, display devices, etc.

[0047] In the embodiment of the present invention, the executable program executed by the processor 420 included in the electronic device includes: Obtaining a mathematical model of interference fringes of a cold atomic dry instrument gyroscope, and linearizing the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; Based on the current sampled transverse fringe phase and atomic transition probability, the linear correlation coefficient in the linear function is obtained by solving the least square method; The range of fringe initial phase values ​​is expanded, and within the expanded range of fringe initial phase values, the interference fringes are fitted based on the linear correlation coefficient and the real-time sampled transverse axis fringe phase and atomic transition probability.

[0048] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0049] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0050] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for fitting interference fringes of a cold atom dry gyroscope, characterized in that: include: Obtaining a mathematical model of interference fringes of a cold atomic dry instrument gyroscope, and linearizing the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; Based on the current sampled transverse fringe phase and atomic transition probability, the linear correlation coefficient in the linear function is obtained by solving the least square method; The range of fringe initial phase values ​​is expanded, and within the expanded range of fringe initial phase values, the interference fringes are fitted based on the linear correlation coefficient and the real-time sampled transverse axis fringe phase and atomic transition probability.

2. The method according to claim 1, characterized in that The linearization processing of the interference fringe mathematical model based on trigonometric functions to obtain the corresponding linear function includes: Based on trigonometric function conversion, the interference fringe mathematical model (1) is converted into formula (2): ；（1） ；（2） definition , , ; The linear function is expressed as: ；（3） In the formula, P represents the atomic transition probability value, P0 represents the fringe bias, and A represents the fringe amplitude. represents the horizontal fringe phase, represents the initial phase of the fringe, , , All represent linear correlation coefficients.

3. The method according to claim 2, characterized in that The method of solving the linear correlation coefficient in the linear function by the least square method also includes: Based on the calculated linear correlation coefficient value and its definition, the fringe bias, fringe amplitude and fringe initial phase are solved.

4. The method according to claim 3, characterized in that The range of values ​​of the initial phase of the extended fringe includes: According to the linear correlation coefficient and The positive or negative value of the fringe is used to determine the quadrant to which the fringe initial phase belongs. Based on the quadrant to which the fringe initial phase belongs, the range of the fringe initial phase value is expanded to .

5. An interference fringe fitting system for a cold atom dry gyroscope, characterized in that: include: A linearization module is used to obtain a mathematical model of interference fringes of a cold atomic dry instrument gyroscope, and to linearize the mathematical model of interference fringes based on trigonometric functions to obtain a corresponding linear function; A coefficient solving module is used to solve the linear correlation coefficient in the linear function by the least square method based on the currently sampled transverse fringe phase and atomic transition probability; The fringe fitting module is used to expand the range of fringe initial phase values. Within the expanded range of fringe initial phase values, the interference fringes are fitted based on the linear correlation coefficient and the real-time sampled transverse axis fringe phase and atomic transition probability.

6. The system according to claim 5, characterized in that The linearization processing of the interference fringe mathematical model based on trigonometric functions to obtain the corresponding linear function includes: Based on trigonometric function conversion, the interference fringe mathematical model (1) is converted into formula (2): ；（1） ；（2） definition , , ; The linear function is expressed as: ；（3） In the formula, P represents the atomic transition probability value, P0 represents the fringe bias, and A represents the fringe amplitude. represents the horizontal fringe phase, represents the initial phase of the fringe, , , All represent linear correlation coefficients.

7. The system according to claim 6, characterized in that The method of solving the linear correlation coefficient in the linear function by the least square method also includes: Based on the calculated linear correlation coefficient value and its definition, the fringe bias, fringe amplitude and fringe initial phase are solved.

8. The system according to claim 7, characterized in that The range of values ​​of the initial phase of the extended fringe includes: According to the linear correlation coefficient and The positive or negative value of the fringe is used to determine the quadrant to which the fringe initial phase belongs. Based on the quadrant to which the fringe initial phase belongs, the range of the fringe initial phase value is expanded to .

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the interference fringe fitting method for a cold atom dry gyroscope as described in any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed, the steps of the interference fringe fitting method for a cold atom dry gyroscope as claimed in any one of claims 1 to 4 are implemented.

Images