Automatic compensation method for three-axis magnetic field of atomic spin inertial measurement device

Abstract

The invention discloses an automatic compensation method for a three-axis magnetic field of an atomic spin inertial measurement device. The method can quickly and accurately compensate the three-axis magnetic field. According to the method, compensation of a Z-direction magnetic field is realized by measuring a three-axis residual magnetic field through a dichotomy, and simultaneous compensation of an X-direction magnetic field and a Y-direction magnetic field is realized through a non-orthogonal decoupling measurement method. The method is reasonable, the experimental operation is simple, the method is suitable for an atomic spin inertial measurement device based on an alkali metal electron spin and inert gas nuclear spin coupling ensemble, the three-axis magnetic field can be rapidly, accurately and automatically compensated in real time, a basis is provided for development of a high-precision atomic spin inertial measurement device, and the workload of device debugging is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of atomic spin inertia measurement, and in particular to a method for automatic compensation of a three-axis magnetic field of an atomic spin inertia measurement device. The experimental operation is simple, and the three-axis magnetic field can be compensated quickly and accurately, which provides a basis for the development of a high-precision atomic spin inertia measurement device and greatly reduces the workload of device debugging. Background Art

[0002] In an atomic spin inertial measurement device, it is usually necessary to set it at a compensation point to maintain high sensitivity to angular velocity signals and abnormal field signals and nuclear spin self-compensation capability, and to maintain low sensitivity to magnetic field signals.

[0003] At present, the three-axis magnetic field automatic compensation method is mainly implemented through square wave modulation, which has the problem of three-axis magnetic field coupling and magnetic field coil coupling. In the face of this problem, although some technologies have tried to provide solutions through optimization methods such as PID (proportional integral differential) algorithm, fuzzy PID algorithm and machine learning algorithm, they have not considered the three-axis magnetic field coupling and magnetic field coil coupling problems, and most of them use multiple iterations to reduce the compensation error, so that the accuracy and efficiency of the existing methods are limited by the experimental methods. Summary of the invention

[0004] In view of the defects or shortcomings in the prior art, the present invention provides a method for automatic compensation of three-axis magnetic field of an atomic spin inertial measurement device. The experimental operation is simple and can quickly and accurately compensate for the three-axis magnetic field, which provides a basis for the development of high-precision atomic spin inertial measurement devices and greatly reduces the workload of device debugging.

[0005] The technical solution of the present invention is as follows:

[0006] A method for automatic compensation of three-axis magnetic field of an atomic spin inertial measurement device, characterized in that it comprises the following steps:

[0007] Step 1, setting the estimated range [Vzmin, Vzmax] of the voltage Vz of the compensation point of the Z-direction magnetic field coil in the atomic spin inertial measurement device, where Vzmin is the minimum voltage of the Z-direction compensation point and Vzmax is the maximum voltage of the Z-direction compensation point;

[0008] Step 2: Determine the initial array [V z0 ,V z1 ,V z2 ], where V z0 =Vzmin,V z1 =Vzmax,V z2 =(Vzmin+Vzmax) / 2;

[0009] Step 3, run the Z-direction residual magnetism measurement program, output Vzi corresponding to the response signal dSi, Vzi is the current Z-direction magnetic field coil compensation point voltage;

[0010] Step 4: Determine whether dSi < 0.05mV. If not, determine the next Z-direction magnetic field coil compensation voltage V according to the binary method. zi+1 Then return to step 3, if yes, then determine the Z-direction magnetic field compensation point and proceed to step 5;

[0011] Step 5, setting the estimated range of the voltage Vx at the X-direction magnetic field compensation point [Vxmin, Vxmax], setting the estimated range of the voltage Vy at the Y-direction magnetic field compensation point [Vymin, Vymax], where min represents the minimum value and max represents the maximum value;

[0012] Step 6, determine the voltage array of the traversed magnetic field compensation points [(Vx1, Vy1), (Vx2, Vy2), ..., (Vxn, Vyn)], where Vxn is the nth Vx, Vyn is the nth Vy, and n is a positive integer;

[0013] Step 7, input [Vxj, Vyj], Vxj is the voltage of the j-th X-direction magnetic field compensation point, Vyj is the voltage of the j-th Y-direction magnetic field compensation point, and j is a counter;

[0014] Step 8, run the X-direction and Y-direction residual magnetism measurement program to obtain the output Vxj, Vyj corresponding to the response signal dSj, ddSj;

[0015] Step 9, determine whether j≥n, if not, set j=j+1 and return to step 7, if yes, proceed to step 10;

[0016] Step 10, decouple the non-orthogonality of the X magnetic field coil and the Y magnetic field coil according to the array and the corresponding output results, and calculate the X-direction magnetic field compensation point and the Y-direction magnetic field compensation point.

[0017] Step 3 includes the following formula:

[0018]

[0019] dS=S1-S2

[0020] Where dS is the first-order approximation of the output signal with respect to the Z-direction magnetic field Bz, Kz is the coefficient, is the gyromagnetic ratio of alkali metal electrons, is the z-axis electronic polarizability, is the Z-axis electron relaxation rate, δB z is the Z-direction residual magnetism, S1 is the output signal high-level steady-state response, and S2 is the output signal low-level steady-state response.

[0021] Step 4 includes the following formula:

[0022]

[0023] V zc1 is the lower limit of the zero magnetic field point range, V zc2 It is the upper limit of the zero magnetic field point range.

[0024] In step 6, n≥6.

[0025] Step 8 includes the following formula:

[0026] dS=S1-S2

[0027] ddS=S1+S2-2S0

[0028] dS=K y B y

[0029] ddS=K x B x

[0030] dS is the first-order approximation of the output signal with respect to the Y-direction magnetic field By, S1 is the high-level steady-state response of the output signal, S2 is the low-level steady-state response of the output signal, S0 is the DC bias steady-state response, ddS is the second-order approximation of the output signal with respect to the X-direction magnetic field Bx, and Ky and Kx are coefficients.

[0031] Step 10 includes the following formula:

[0032]

[0033] Where M is a 2×2 non-orthogonal matrix consisting of the X-direction coil and the Y-direction coil, B y0 is the Y-axis residual magnetism, B x0 is the X-axis residual magnetism, and the X-direction magnetic compensation point and the Y-direction magnetic compensation point are determined by solving the obtained M.

[0034] The expressions of the X-direction magnetic compensation point and the Y-direction magnetic compensation point are as follows:

[0035]

[0036] Where V y0 is the Y-direction magnetic field coil compensation voltage, V x0 is the compensation voltage of the X-direction magnetic field coil.

[0037] The advantages of the present invention compared with the prior art are:

[0038] (1) The present invention realizes automatic compensation of the three-axis magnetic field of the atomic spin inertial measurement device through the dichotomy method and the non-orthogonal decoupling measurement method. Compared with the existing method, it solves the influence of the three-axis magnetic field coupling and the XY magnetic field coupling, and applies the decoupling method to the XY magnetic field compensation. The XY compensation point can be directly calculated, thereby realizing fast and accurate three-axis magnetic field compensation.

[0039] (2) The method of the present invention is reasonable and the experimental operation is simple, which provides a basis for the development of a high-precision atomic spin inertial measurement device and greatly reduces the workload of device debugging. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a schematic flow chart of a method for automatically compensating a three-axis magnetic field of an atomic spin inertial measurement device. Figure 1 The method includes step 1, setting the estimated range of the voltage Vz at the compensation point of the Z-direction magnetic field coil [Vzmin, Vzmax], where Vzmin is the minimum voltage at the compensation point of the Z-direction magnetic field coil, and Vzmax is the maximum voltage at the compensation point of the Z-direction magnetic field coil; step 2, determining the initial array [V z0 ,V z1 ,V z2 ], where V z0 =Vzmax,V z1 =Vzmin,V z2 =(Vzmax+Vzmin) / 2; Step 3, run the Z-direction residual magnetism measurement program, output Vzi corresponding to the response signal dSi, Vzi is the current Z-direction magnetic field coil compensation point voltage; Step 4, determine whether dSi < 0.05mV, if not, determine the next Z-direction magnetic field coil compensation voltage V according to the dichotomy method z i+1 Then return to step 3. If yes, determine the Z-direction magnetic field compensation point and then enter step 5; step 5, set the estimated range of the voltage Vx of the X-direction magnetic field compensation point [Vxmin, Vxmax], set the estimated range of the voltage Vy of the Y-direction magnetic field compensation point [Vymin, Vymax], min represents the minimum value, and max represents the maximum value; step 6, determine the traversal magnetic field compensation point voltage array [(Vx1, Vy1), (Vx2, Vy2), ..., (Vxn, Vyn)], Vxn is the nth Vx, Vyn is the nth Vy, and n is a positive integer; step 7 , input [Vxj, Vyj], Vxj is the voltage of the j-th X-direction magnetic field compensation point, Vyj is the voltage of the j-th Y-direction magnetic field compensation point, and j is a counter; step 8, run the X-direction and Y-direction residual magnetism measurement programs to obtain the output Vxj, Vyj corresponding to the response signals dSj, ddSj; step 9, determine whether j≥n, if not, set j=j+1 and return to step 7, if yes, enter step 10; step 10, decouple the non-orthogonality of the X-direction magnetic field coil and the Y-direction magnetic field coil according to the array and the corresponding output results, and calculate the X-direction magnetic field compensation point and the Y-direction magnetic field compensation point. DETAILED DESCRIPTION

[0041] Below is the attached figure ( Figure 1 ) and Examples illustrate the present invention.

[0042] Figure 1 The figure is a flow chart of a method for automatically compensating a three-axis magnetic field of an atomic spin inertial measurement device according to the present invention. Figure 1 As shown, a method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device comprises the following steps: step 1, setting an estimated range [Vzmin, Vzmax] of the voltage Vz of the compensation point of the Z-direction magnetic field coil in the atomic spin inertial measurement device, where Vzmin is the minimum voltage of the Z-direction compensation point and Vzmax is the maximum voltage of the Z-direction compensation point; step 2, determining the initial array [V z0 ,V z1 ,V z2 ], where V z0 =Vzmin,V z1 =Vzmax,V z2 =(Vzmin+Vzmax) / 2; Step 3, run the Z-direction residual magnetism measurement program, output the response signal dSi corresponding to Vzi, Vzi is the current Z-direction magnetic field coil compensation point voltage; Step 4, determine whether dSi < 0.05mV, if not, determine the next Z-direction magnetic field coil compensation voltage V according to the dichotomy method z i+1 Then return to step 3. If yes, determine the Z-direction magnetic field compensation point and then enter step 5; step 5, set the estimated range of the voltage Vx of the X-direction magnetic field compensation point [Vxmin, Vxmax], set the estimated range of the voltage Vy of the Y-direction magnetic field compensation point [Vymin, Vymax], min represents the minimum value, and max represents the maximum value; step 6, determine the traversal magnetic field compensation point voltage array [(Vx1, Vy1), (Vx2, Vy2), ..., (Vxn, Vyn)], Vxn is the nth Vx, Vyn is the nth Vy, and n is a positive integer; step 7 , input [Vxj, Vyj], Vxj is the voltage of the j-th X-direction magnetic field compensation point, Vyj is the voltage of the j-th Y-direction magnetic field compensation point, and j is a counter; step 8, run the X-direction and Y-direction residual magnetism measurement programs to obtain the output Vxj, Vyj corresponding to the response signals dSj, ddSj; step 9, determine whether j≥n, if not, set j=j+1 and return to step 7, if yes, enter step 10; step 10, decouple the non-orthogonality of the X-direction magnetic field coil and the Y-direction magnetic field coil according to the array and the corresponding output results, and calculate the X-direction magnetic field compensation point and the Y-direction magnetic field compensation point.

[0043] Step 3 includes the following formula:

[0044]

[0045] dS=S1-S2

[0046] Where dS is the first-order approximation of the output signal with respect to the Z-direction magnetic field Bz, Kz is the coefficient, is the gyromagnetic ratio of alkali metal electrons, is the z-axis electronic polarizability, is the Z-axis electron relaxation rate, δB z is the Z-direction magnetic field, S1 is the output signal high level steady-state response, and S2 is the output signal low level steady-state response.

[0047] Step 4 includes the following formula:

[0048]

[0049] V zc1 is the lower limit of the zero magnetic field point range, V zc2 It is the upper limit of the zero magnetic field point range.

[0050] In step 6, n≥6.

[0051] Step 8 includes the following formula:

[0052] dS=S1-S2

[0053] ddS=S1+S2-2S0

[0054] dS=K y B y

[0055] ddS=K x b x

[0056] dS is the first-order approximation of the output signal with respect to the Y-direction magnetic field By, S1 is the high-level steady-state response of the output signal, S2 is the low-level steady-state response of the output signal, S0 is the DC bias steady-state response, ddS is the second-order approximation of the output signal with respect to the X-direction magnetic field Bx, and Ky and Kx are coefficients.

[0057] Step 10 includes the following formula:

[0058]

[0059] Where M is a 2×2 non-orthogonal matrix consisting of the X-direction coil and the Y-direction coil, B y0 is the Y-axis residual magnetism, B x0 is the X-axis residual magnetism, and the X-direction magnetic compensation point and the Y-direction magnetic compensation point are determined by solving the obtained M.

[0060] The expressions of the X-direction magnetic compensation point and the Y-direction magnetic compensation point are as follows:

[0061]

[0062] Where V y0 is the Y-direction magnetic field coil compensation voltage, V x0 is the compensation voltage of the X-direction magnetic field coil.

[0063] The present invention relates to a method for automatic compensation of three-axis magnetic field of an atomic spin inertial measurement device, which can quickly and accurately compensate for the three-axis magnetic field. The method measures the three-axis residual magnetic field, realizes compensation of the Z-direction magnetic field by a dichotomy method, and realizes simultaneous compensation of the X-direction and Y-direction magnetic fields by a non-orthogonal decoupling measurement method. The method of the present invention is reasonable, and the experimental operation is simple. It is suitable for an atomic spin inertial measurement device based on an ensemble of coupled alkali metal electron spins and inert gas nuclear spins, and can automatically and accurately compensate for the three-axis magnetic field in real time, quickly, and accurately, providing a basis for the development of a high-precision atomic spin inertial measurement device, and greatly reducing the workload of device debugging.

[0064] like Figure 1 As shown, the present invention provides a three-axis magnetic field automatic compensation method for an atomic spin inertial measurement device, comprising the following steps:

[0065] Step (1): Set the estimated range of the voltage at the compensation point of the Z-direction magnetic field coil [V zmin ,V zmax ], determine the initial array [V z0 ,V z1 ,V z2 ], where V z0 =V zmin ,V z1 =V zmax ,V z2 =(V zmin +V zmax ) / 2, counter i=i+1.

[0066] Step (2): Run the Z-direction residual magnetism measurement program and output V zi Corresponding response signal dS i .

[0067] Step (3): If dS is less than 0.05mV, then end; otherwise, determine the next Z-direction magnetic field V according to the dichotomy method. z i+1 , repeat step (2), counter i=i+1.

[0068] Step (4): Set the estimated range of the X-direction and Y-direction magnetic field compensation points [V xmin V xmax ]、[V ymin V ymax ], determine to traverse the magnetic field array [(V x1 ,V y1 ),(V x1,V y1 ),…,(V xn ,V yn )].

[0069] Step (5): Run the X-direction and Y-direction residual magnetism measurement program, output the response signals dS and ddS, and traverse the array [(V x1 ,V y1 ),(V x1 ,V y1 ),…,(V xn ,V yn )].

[0070] Step (6): Decouple the non-orthogonality of the X and Y magnetic field coils based on the array and the corresponding output results, and calculate the X and Y magnetic field compensation points.

[0071] The estimated range of the voltage at the Z-direction compensation point in step (1) is [V zmin ,V zmax ],V z0 =V zmin ,V z1 =V zmax ,V z2 =(V zmin +V zmax ) / 2.

[0072] The Z-direction residual magnetism measurement procedure in step (2) is to obtain the difference S1-S2 between the high-level steady-state response S1 and the low-level steady-state response S2 of the output signal by square wave modulation of the Y-direction magnetic field, which is recorded as dS. dS is the first-order approximation of the output signal with respect to the Y-direction magnetic field. dS is linearly dispersive with the Z-direction magnetic field, and the relationship is as follows:

[0073]

[0074] The specific operation steps of the dichotomy method in step (3) are as follows: first, determine the range boundary of the zero point as V zc1 、V zc2 , where V zc2 =V zi , dS i ×D i-1 <0, then V zc1 =V zi-1 , otherwise V zc2 =V zi-2 In step (3)

[0075] The array [(V x1 ,V y1 ),(V x1 ,V y1 ),…,(Vxn ,V yn )] is within the estimated range [V xmin V xma x]、[V ymin V ymax ] is composed of 3 or more arrays in which the X-direction magnetic field coil voltage remains unchanged and the Y-direction magnetic field voltage changes, and 3 or more arrays in which the Y-direction magnetic field coil voltage remains unchanged and the X-direction magnetic field voltage changes, n is a positive integer, n≥6.

[0076] In the step (5), the X-direction and Y-direction residual magnetism measurement procedures are to obtain the difference S1-S2 between the high-level steady-state response S1 and the low-level steady-state response S2 of the output signal by adding DC modulation to the Z-direction magnetic field square wave, which is recorded as dS. dS is the first-order approximation of the output signal with respect to the Y-direction magnetic field; the sum S1+S2 of the high-level steady-state response S1 and the low-level steady-state response S2 of the output signal minus the difference S1+S2-2S0 of twice the DC bias steady-state response S0, which is recorded as ddS. ddS is the second-order approximation of the output signal with respect to the X-direction magnetic field. dS is linearly related to the Y-direction magnetic field, and ddS is linearly related to the X-direction magnetic field, and the relationship is as follows:

[0077] dS=K y B y

[0078] ddS=K x B x

[0079] In step (6), the XY coil voltage V x , V y 、XY direction remanence B x0 , B y0 The relationship between dS and ddS is as follows:

[0080]

[0081] Wherein, M is a 2×2 non-orthogonal matrix of XY coils.

[0082] According to the traversal array [(V x1 ,V y1 ),(V x1 ,V y1 ),…,(V xn ,V yn )] The corresponding dS, ddS can be solved to obtain the non-orthogonal matrix M and the XY magnetic compensation point

[0083] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. It is pointed out here that the above description helps those skilled in the art to understand the invention, but does not limit the protection scope of the invention. Any equivalent replacement, modification and / or simplification of the above description without departing from the essence of the invention falls within the protection scope of the invention.

Claims

1. A method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device, characterized in that: The following steps are involved: Step 1, setting the estimated range [Vzmin, Vzmax] of the voltage Vz of the compensation point of the Z-direction magnetic field coil in the atomic spin inertial measurement device, where Vzmin is the minimum voltage of the Z-direction compensation point and Vzmax is the maximum voltage of the Z-direction compensation point; Step 2: Determine the initial array [V z0 ,V z1 ,V z2 ], where V z0 =Vzmin,V z1 =Vzmax,V z2 =(Vzmin+Vzmax) / 2; Step 3, run the Z-direction residual magnetism measurement program, output Vzi corresponding to the response signal dSi, Vzi is the current Z-direction magnetic field coil compensation point voltage; Step 4: Determine whether dSi < 0.05mV. If not, determine the next Z-direction magnetic field coil compensation voltage V according to the binary method. z i+1 Then return to step 3, if yes, then determine the Z-direction magnetic field compensation point and proceed to step 5; Step 5, setting the estimated range of the voltage Vx at the X-direction magnetic field compensation point [Vxmin, Vxmax], setting the estimated range of the voltage Vy at the Y-direction magnetic field compensation point [Vymin, Vymax], where min represents the minimum value and max represents the maximum value; Step 6, determine the voltage array of the traversed magnetic field compensation points [(Vx1, Vy1), (Vx2, Vy2), ..., (Vxn, Vyn)], where Vxn is the nth Vx, Vyn is the nth Vy, and n is a positive integer; Step 7, input [Vxj, Vyj], Vxj is the voltage of the j-th X-direction magnetic field compensation point, Vyj is the voltage of the j-th Y-direction magnetic field compensation point, and j is a counter; Step 8, run the X-direction and Y-direction residual magnetism measurement program to obtain the output Vxj, Vyj corresponding to the response signal dSj, ddSj; Step 9, determine whether j≥n, if not, set j=j+1 and return to step 7, if yes, proceed to step 10; Step 10, decouple the non-orthogonality of the X magnetic field coil and the Y magnetic field coil according to the array and the corresponding output results, and calculate the X-direction magnetic field compensation point and the Y-direction magnetic field compensation point.

2. The method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device according to claim 1, characterized in that: Step 3 includes the following formula: dS=S1-S2 Where dS is the first-order approximation of the output signal with respect to the Z-direction magnetic field Bz, Kz is the coefficient, γ e is the gyromagnetic ratio of alkali metal electrons, is the z-axis electronic polarizability, is the Z-axis electron relaxation rate, δB z is the Z-direction magnetic field, S1 is the output signal high level steady-state response, and S2 is the output signal low level steady-state response.

3. The method for automatic three-axis magnetic field compensation of an atomic spin inertial measurement device according to claim 1, characterized in that: Step 4 includes the following formula: V zc1 is the lower limit of the zero magnetic field point range, V zc2 It is the upper limit of the zero magnetic field point range.

4. The method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device according to claim 1, characterized in that: In step 6, n≥6.

5. The method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device according to claim 1, characterized in that: Step 8 includes the following formula: dS=S1-S2 ddS=S1+S2-2S0 dS=K y B y ddS=K x B x dS is the first-order approximation of the output signal with respect to the Y-direction magnetic field By, S1 is the high-level steady-state response of the output signal, S2 is the low-level steady-state response of the output signal, S0 is the DC bias steady-state response, ddS is the second-order approximation of the output signal with respect to the X-direction magnetic field Bx, and Ky and Kx are coefficients.

6. The method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device according to claim 1, characterized in that: Step 10 includes the following formula: Where M is a 2×2 non-orthogonal matrix consisting of the X-direction coil and the Y-direction coil, B y0 is the Y-axis residual magnetism, B x0 is the X-axis residual magnetism, and the X-direction magnetic compensation point and the Y-direction magnetic compensation point are determined by solving the obtained M.

7. The method for automatic compensation of three-axis magnetic field of atomic spin inertial measurement device according to claim 1, characterized in that: The expressions including the X-direction magnetic compensation point and the Y-direction magnetic compensation point are as follows: Where V y0 is the Y-direction magnetic field coil compensation voltage, V x0 is the compensation voltage of the X-direction magnetic field coil.

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