Fiber optic gyroscope arcsine closed-loop control method, electronic equipment and media

Abstract

This invention provides an arcsine closed-loop control method, electronic device, and medium for a fiber optic gyroscope. The method includes quantizing the absolute value of the optical power response difference into a first value; converting the first value into a second value based on an arcsine mapping model between the first and second values; multiplying the sign of the optical power response difference by the second value to obtain the actual phase difference; and using the actual phase difference as input error for closed-loop control of the fiber optic gyroscope to obtain its rotational angular rate. This invention establishes an arcsine mapping between the optical power response difference and the actual phase difference, converting the nonlinear sinusoidal transmission relationship between the phase difference and the control system input error signal into a linear transmission relationship. This results in more accurate error transmission, more stable closed-loop control of the fiber optic gyroscope, and better dynamic performance. This invention can solve the problem of measurement errors in the rotational angular rate of fiber optic gyroscopes under large angular acceleration conditions.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic gyroscope control technology, and specifically relates to a method, electronic device and medium for arcsine closed-loop control of a fiber optic gyroscope. Background Technology

[0002] A fiber optic gyroscope is a rotational angular rate measurement device based on the Sagnac effect. The optical path difference generated by light in the Sagnac effect is proportional to the rotational angular velocity; a constant velocity Ω will produce a constant phase difference Δφ. R The phase difference of this Sagnac is Δφ R =2πLDΩ / λc, where λ is the wave in vacuum, L is the length of the optical fiber, D is the diameter of the optical fiber loop, and c is the speed of light in vacuum.

[0003] Sagnac phase difference Δφ R After passing through a PIN-FET, it is converted into an optical power response P(Δφ). R ), which is a raised cosine function P(Δφ) R )=P0[1+cosΔφ R ], when Δφ R The maximum value is reached when Δφ = 0. To obtain high sensitivity, a bias is generally applied to the signal, causing it to operate near a point where the response slope is not zero: P(Δφ) R )=P0[1+cos(Δφ R +φ b )], where φ b This is for phase offset.

[0004] A reciprocal phase modulator (Y-waveguide) is placed at one end of the fiber optic loop as a time delay line to achieve a phase difference bias modulation, such as... Figure 1 As shown. At this time, P(Δφ) R )=P0[1+cos[Δφ R +Δφ m (t))].

[0005] A square wave is used for modulation φ m =±(φ b / 2) to achieve this, where the half-period of the square wave is equal to Δτ. g (Corresponding to the intrinsic frequency of the fiber optic ring), such as Figure 2 As shown.

[0006] The difference in optical power response under the two square wave modulation states is ΔP(Δφ). R ,φ b )=2P0sinφ b sinΔφ R .

[0007] The fiber optic gyroscope closed-loop control system uses modulation and demodulation hardware circuitry to control ΔP(Δφ). R ,φ b After analog amplification, filtering, and analog-to-digital conversion, the result is ΔP(Δφ). R ,φ b ) as error input (the actual error is Δφ) R The Y-waveguide is driven by a PID feedback control algorithm to perform phase compensation, thereby realizing closed-loop control of the fiber optic gyroscope and obtaining the input rotational angular rate value.

[0008] Under stable closed-loop control conditions, Δφ R It is a very small value, at which point sinΔφ R ≈Δφ R The error ΔP(Δφ) collected by the fiber optic gyroscope closed-loop control system R ,φ b ) and Δφ R Proportional to the specified values, closed-loop control can be correctly achieved.

[0009] When the fiber optic gyroscope has a large acceleration, ΔP(Δφ) R ,φ b ) and Δφ R Since the relationship is nonlinear sinusoidal, the error signal acquired by the modulation and demodulation hardware circuit cannot accurately reflect the true phase difference. At this time, the fiber optic gyroscope closed-loop control system cannot accurately track the input error, which will lead to system divergence and failure. The closed-loop control will fail, the rotational angular rate measurement will be incorrect, and the fiber optic gyroscope function will fail. Summary of the Invention

[0010] The purpose of this invention is to address the shortcomings of existing technologies by providing a sinusoidal closed-loop control method, electronic device, and medium for fiber optic gyroscopes. This method transforms the nonlinear sinusoidal transmission relationship between phase difference and the input error signal of the control system into a linear transmission relationship, resulting in more accurate error transmission, more stable closed-loop control, and better dynamic performance. It also solves the problem of measurement error in the rotational angular rate of fiber optic gyroscopes under large angular acceleration conditions.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] A closed-loop control method for arcsine wave propagation of a fiber optic gyroscope includes the following steps:

[0013] Obtain the optical power response difference of the fiber optic gyroscope and quantize the absolute value of the optical power response difference into a first value;

[0014] Based on the arcsine relationship mapping model between the first and second values, the first value is transformed into the second value. The expression for the arcsine relationship mapping model between the first and second values ​​is as follows:

[0015]

[0016] The actual phase difference is obtained by multiplying the sign of the optical power response difference by the second value;

[0017] The actual phase difference is used as the input error for closed-loop control of the fiber optic gyroscope to obtain the rotational angular rate value of the fiber optic gyroscope.

[0018] Where Di is the first value, Dpi is the second value, M is the bit width of the first value, and N is the bit width of the second value.

[0019] This invention establishes an arcsine relationship mapping between the optical power response difference and the actual phase difference, transforming the nonlinear sinusoidal transmission relationship between the phase difference and the input error signal of the control system into a linear transmission relationship. This results in more accurate error transmission, more stable closed-loop control of the fiber optic gyroscope, and better dynamic performance. The arcsine closed-loop control can solve the problem of measurement error in the rotational angular rate of the fiber optic gyroscope under large angular acceleration conditions. It will not have any adverse effects on the stable closed-loop control of the fiber optic gyroscope in small angular acceleration scenarios.

[0020] Furthermore, the first value is obtained through the following formula:

[0021]

[0022] Wherein, ΔP(Δφ) R ,φ b P0 represents the optical power response difference, and Pmax represents the maximum absolute value of the optical power response difference.

[0023] Furthermore, the range of the first value is 0 to 2. M -1, the second value ranges from 0 to 2. N -1.

[0024] Furthermore, the expression for the optical power response difference is as follows:

[0025] ΔP(Δφ R ,φ b )=2P0sinφ b sinΔφ R ;

[0026] Where P0 is the initial optical power, φ b For phase bias, Δφ R This is the Sagnac phase difference.

[0027] Based on the same inventive concept, the present invention also provides an electronic device, comprising:

[0028] One or more processors;

[0029] A memory storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the steps of the fiber optic gyroscope arcsine closed-loop control method.

[0030] Based on the same inventive concept, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of a fiber optic gyroscope arcsine closed-loop control method.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention establishes an arcsine relationship mapping between the optical power response difference and the actual phase difference, transforming the nonlinear sinusoidal transmission relationship between the phase difference and the input error signal of the control system into a linear transmission relationship. This results in more accurate error transmission, more stable closed-loop control of the fiber optic gyroscope, and better dynamic performance. The arcsine closed-loop control can solve the problem of measurement error in the rotational angular rate of the fiber optic gyroscope under large angular acceleration conditions. It will not have any adverse effects on the stable closed-loop control of the fiber optic gyroscope in small angular acceleration scenarios. Attached Figure Description

[0033] Figure 1 A schematic diagram illustrating the use of an optical fiber loop as a time delay to generate bias phase modulation;

[0034] Figure 2 This is a schematic diagram of square wave bias modulation;

[0035] Figure 3 This is a schematic diagram of the arcsine closed-loop control method for fiber optic gyroscopes according to an embodiment of the present invention. Detailed Implementation

[0036] The present invention will be described in detail below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. For ease of description, the words "upper," "lower," "left," and "right" appearing below only indicate that they are consistent with the upper, lower, left, and right directions of the drawings themselves, and do not limit the structure.

[0037] Example

[0038] To address the issue of divergence and failure in the closed-loop control system of fiber optic gyroscopes under large accelerations, this embodiment proposes an arcsine closed-loop control method for fiber optic gyroscopes. The input error sinΔφ is then incorporated into the FPGA. R The true error Δφ is obtained using arcsine mapping. R Then, it is used as the input error for closed-loop control.

[0039] like Figure 3The fiber optic gyroscope arcsine closed-loop control method of this embodiment includes:

[0040] 1) Use tools such as MATLAB and Excel to establish a correspondence between the digital value Dp and the digital address Addr, satisfying the following relationship:

[0041]

[0042] Where N is the bit width of the digital quantity Dp, and M is the bit width of the address digital quantity Addr. The bit widths of the digital quantity Dp and the address digital quantity Addr are selected according to actual needs, for example, M and N are both 12; the range of the digital quantity Dp is 0 to 2. N -1, the range of the address numeric value Addr is 0 to 2. M -1.

[0043] 2) Establish a lookup table Table based on a single-port ROM in the FPGA to establish the correspondence between digital quantity Dp and address digital quantity Addr, where Addr is the address.

[0044] 3) The difference in optical power response ΔP(Δφ) in the FPGA. R ,φ b After digital processing (analog amplification and filtering, analog-to-digital conversion, etc.), its absolute value is quantized into a numerical value Di with an M-bit width, and ΔP(Δφ) is stored. R ,φ b The positive and negative sign of Si is indicated by ).

[0045]

[0046] Wherein, ΔP(Δφ) R ,φ b P0 represents the optical power response difference, and Pmax represents the maximum absolute value of the optical power response difference.

[0047] ΔP(Δφ R ,φ b )=2P0sinφ b sinΔφ R (3)

[0048] Where P0 is the initial optical power, φ b For phase bias, Δφ R This is the Sagnac phase difference.

[0049] 4) Using the value Di as the address, obtain the corresponding value Dpi from formula (1);

[0050] 5) Multiply Si by the numerical value Dpi to obtain the true phase difference Phi.

[0051] 6) The phase difference Phi is used as the input error for closed-loop control of the fiber optic gyroscope to obtain its rotational angular rate. Closed-loop control of the fiber optic gyroscope is the basic control method and is existing technology.

[0052] The characteristic of this fiber optic gyroscope closed-loop control method is as follows:

[0053] The optical path and circuitry of existing fiber optic gyroscopes do not need to be modified and can remain unchanged.

[0054] Using FPGA for data processing and computation;

[0055] Establish input error ΔP(Δφ) in FPGA R ,φ b ) and the true Δφ R The arcsine relationship mapping between them;

[0056] The phase difference signal mapped by the arcsine relationship is used as the error input of the fiber optic gyroscope closed-loop control algorithm;

[0057] The Y-waveguide is driven by a combination of square wave modulation and stepped wave feedback modulation (this debugging method is existing technology).

[0058] The advantages of the fiber optic gyroscope arcsine closed-loop control method in this embodiment are:

[0059] By converting the nonlinear sinusoidal transmission relationship between the phase difference and the input error signal of the control system into a linear transmission relationship, the error transmission is more accurate, the closed-loop control of the fiber optic gyroscope is more stable, and the dynamic performance is better.

[0060] Using existing hardware circuits and optical systems, arcsine data processing is performed via FPGA, which is low-cost and offers simple and flexible data processing.

[0061] The arcsine closed-loop control of fiber optic gyroscopes can solve the problem of measurement error in the rotational angular rate of fiber optic gyroscopes under large angular acceleration conditions. The arcsine closed-loop control of fiber optic gyroscopes will not have any adverse effects on the stability of fiber optic gyroscope closed-loop control in operating scenarios with small angular acceleration.

[0062] Another embodiment of the present invention provides an electronic device, comprising:

[0063] One or more processors;

[0064] A memory that stores one or more programs, which, when executed by one or more processors, cause one or more processors to implement the steps of the fiber optic gyroscope arcsine closed-loop control method.

[0065] In some implementations, the memory may be high-speed random access memory (RAM), and may also include non-volatile memory, such as at least one disk storage device.

[0066] In other implementations, the processor can be any type of general-purpose processor, such as a central processing unit (CPU) or a digital signal processor (DSP), and there is no limitation here.

[0067] Another embodiment of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of a fiber optic gyroscope arcsine closed-loop control method.

[0068] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. A closed-loop control method for an arcsine wave of a fiber optic gyroscope, characterized in that, The process includes the following: Obtain the optical power response difference of the fiber optic gyroscope and quantize the absolute value of the optical power response difference into a first value; Based on the arcsine relationship mapping model between the first and second values, the first value is transformed into the second value. The expression for the arcsine relationship mapping model between the first and second values ​​is as follows: The actual phase difference is obtained by multiplying the sign of the optical power response difference by the second value; The actual phase difference is used as the input error for closed-loop control of the fiber optic gyroscope to obtain the rotational angular rate value of the fiber optic gyroscope. Where Di is the first value, Dpi is the second value, M is the bit width of the first value, and N is the bit width of the second value; The first value is obtained using the following formula: in, Pmax is the absolute value of the optical power response difference.

2. The fiber optic gyroscope arcsine closed-loop control method according to claim 1, characterized in that, The first value ranges from 0 to 2. M -1, the second value ranges from 0 to 2. N -1.

3. The fiber optic gyroscope arcsine closed-loop control method according to claim 1, characterized in that, The expression for the optical power response difference is as follows: ΔP(Δϕ R ,ϕ b )=2P0sinϕ b sinΔϕ R Where P0 is the initial optical power, ϕ b For phase offset, Δϕ R This is the Sagnac phase difference.

4. An electronic device, characterized in that, include: One or more processors; A memory having stored one or more programs that, when executed by one or more processors, cause the one or more processors to perform the steps of the method according to any one of claims 1-3.

5. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1-3.

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