A design method of single-axis rotation modulation inertial navigation system based on hemispherical resonator gyro

Abstract

The application discloses a design method of a single-axis rotation modulation inertial navigation system based on a hemispherical resonator gyro, and comprises the following steps: establishing a standing wave angular rate ideal model of the hemispherical resonator gyro, constructing an angular rate measurement model based on the model, and obtaining an angular rate error model by solving an error; determining a standing wave angular rotation condition to be met under uniform rotation based on the integral characteristics of the angular rate error model; based on the standing wave angular rotation condition, installing each hemispherical resonator gyro's sensitive axis and the rotation modulation axis of the base coordinate system in a skew manner according to the scale factor of the hemispherical resonator gyro, and determining the value condition of the skew angle; on the basis of completing the skew angle configuration, adopting a two-position intermittent single-axis rotation scheme, and determining rotation parameters; setting the ADB phase and control strategy of the stop stage, determining the installation configuration of the hemispherical resonator gyro sensitive axis and the accelerometer, so that the standing wave angle always meets the standing wave angular rotation condition in the rotation process, thereby eliminating the ADB cumulative error.

Description

Technical Field

[0001] This invention belongs to the field of inertial navigation technology, specifically relating to a design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope. Background Technology

[0002] A hemispherical resonator gyroscope (HRG) is a type of vibrating gyroscope based on the Coriolis effect. It senses angular motion by detecting the precession of the standing waves of a resonator. It boasts numerous advantages, including simple structure, high reliability, long lifespan, and theoretical accuracy independent of its size, making it a hot topic in current high-precision inertial navigation technology research. Since the 1960s, countries such as the United States, the Soviet Union (Russia), France, and China have conducted extensive research on it. In recent years, particularly with the widespread application of HRG technology from the French company Safran in maritime, aviation, and aerospace fields, a new wave of research into HRG-related technologies has emerged. The whole-angle (WA) operating mode of the HRG offers a wide dynamic measurement range, making it highly suitable for strapdown inertial navigation systems (SINS), and represents the main direction of current HRG development.

[0003] However, due to anisotropic defects inherent in the fabrication of hemispherical harmonic oscillators, WA-HRGs exhibit circumferential drift, also known as angle-dependent bias (ADB). While self-calibration techniques based on self-excited virtual Coriolis precession can theoretically compensate for ADB, self-excitation inevitably introduces additional control and measurement errors, reducing gyroscope accuracy. Furthermore, the precession magnitude provided by self-excitation is generally small, making perfect error self-calibration difficult to achieve under large-angle dynamic environments. Therefore, in SINS applications, ADB easily leads to significant inertial navigation errors. Summary of the Invention

[0004] The purpose of this invention is to provide a design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope, so as to overcome the problem that the angle correlation zero position in the prior art can easily cause large inertial navigation errors, thereby affecting the accuracy of inertial navigation.

[0005] To achieve the above objectives, the present invention employs the following technical solution: A design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope includes: Construct coordinate systems to provide reference bases for error modeling and rotation modulation; An ideal model of the standing wave angular rate of a hemispherical resonant gyroscope is established. Based on this, an angular rate measurement model is constructed, and the angular rate error model is obtained by calculating the error. Based on the integral characteristics of the angular rate error model, the standing wave angular rotation condition that needs to be satisfied under uniform rotation is determined. Based on the standing wave angle rotation condition, according to the scaling factor of the hemispherical resonant gyroscope, the sensitive axis of each hemispherical resonant gyroscope is installed at an angle to the rotation modulation axis of the base coordinate system, and the value condition of the angle is determined. Based on the completed skew angle configuration, a two-position intermittent single-axis rotation scheme is adopted, and the rotation parameters are determined. The ADB phase and control strategy for the stopping phase are set, and the installation configuration of the hemispherical resonant gyroscope sensitive axis and accelerometer is determined so that the standing wave angle always meets the standing wave angle rotation condition during the rotation process, thereby eliminating the ADB cumulative error.

[0006] Furthermore, the coordinate system includes: Base coordinate system The coordinate system, with the coordinate axes defined as follows: Axis to the right, Axial forward, Axially upward, where The shaft serves as a rotation modulation shaft; Three hemispherical resonant gyroscopes' sensitive axis coordinate system This is a non-orthogonal coordinate system; Inertial sensor coordinate system after orthogonal projection calibration The system, also known as the strapdown inertial coordinate system, has rotation axes. shaft and Department The axes coincide.

[0007] Furthermore, the ideal model for the standing wave angular rate of a hemispherical resonant gyroscope is as follows: ; in: , The standing wave angular rate and standing wave angle are the output values ​​of the hemispherical resonant gyroscope. Scale factor; This is the input angular rate of the sensitive axis of the hemispherical resonant gyroscope relative to inertial space; The precession coefficient of the standing wave caused by circumferential drift; The initial azimuth angle of the circumferential zero-bias standing wave; Rearrange the ideal standing wave angular rate model to transform it into an angular rate measurement model: ; By calculating the errors on both sides of the standing wave angular rate measurement model, we obtain the angular rate error model: ; in, This refers to the error in angular rate measurement. This represents the measurement error of the standing wave angular rate; This represents the measurement error of the standing wave angle position; This is the scaling factor error; For ADB amplitude error; For ADB phase error; Due to the measurement error of the standing wave angle The equivalent angular rate noise caused by its derivative; Assuming the standing wave angular rate is constant And the standing wave angle changes with time Linear change: , The initial standing wave angular rate is given; the equivalent angular rate noise is ignored. Then, the angular rate error model was applied in the standing wave angle range. Integrating, we get: ; If the standing wave angle is uniform and the rotation is continuous, then... For the angle, the cumulative measurement error of the angular rate caused by the ADB zero bias is 0, leaving only the scale factor error, which is proportional to the size of the angle; where It is an integer.

[0008] Furthermore, the input sensing axis of the hemispherical resonant gyroscope is mounted at an angle to the rotation modulation axis of the base coordinate system, with an angle of [missing information]. The following conditions must be met for the value to be taken: ; in The scaling factor is used; the above formula indicates that when the SIMU rotates... At 90°, the standing wave angle of the hemispherical resonant gyroscope rotates exactly... week; The three hemispherical resonant gyroscopes are not coplanar in their sensitive axes and are installed perpendicular or nearly perpendicular to each other.

[0009] Furthermore, the two-position intermittent single-axis rotation scheme includes: For a single-axis rotationally modulated inertial navigation system, each rotation or Both the north and south directions are set to the stop position; the stop position can also be set to other directions that are 90° or 180° apart.

[0010] Furthermore, the rotation parameters Must meet It is an integer.

[0011] Furthermore, the ADB phase and control strategy during the stopping phase are defined, including: During the stopping phase of rotation modulation, the ADB phase of all three hemispherical resonant gyroscopes is set to... or Or in its vicinity; adopt a free azimuth rotation strategy to slowly deflect around the azimuth axis, so that the equivalent azimuth cumulative angle increment output of the SIMU is 0 in each modulation cycle.

[0012] Further, the mounting configuration of the hemispherical resonant gyroscope's sensitive axis is determined, including: When designing the coordinate system of the sensitive axes of the three hemispherical resonant gyroscopes, the sensitive axes of the three hemispherical resonant gyroscopes are compared with the coordinate system of the strapdown inertial navigation system. The skew angles between the axes are configured to be the same value. Furthermore, the three hemispherical resonant gyroscopes are in the strapdown inertial coordinate system. of The projection on the plane is Uniformly distributed.

[0013] Furthermore, the unit vector pointing to the three hemispherical resonant gyroscopes is solved as follows: remember The unit vector of the sensitive axis of the hemispherical resonant gyroscope is projected onto the strapdown inertial navigation system coordinate system as follows: ; If Around a unit vector Rotate -120° to get Unit vector of the sensitive axis of the hemispherical resonant gyroscope , and will Around vector Rotate 120° to obtain Unit vector of the sensitive axis of the hemispherical resonant gyroscope ; and The angle between the sensitive axes of the hemispherical resonant gyroscope is: ; This value is also the angle between any two sensitive axes of the three hemispherical resonant gyroscopes; the superscript T in the parameter indicates transpose.

[0014] Further, determine the installation configuration of the accelerometer, including: For the installation angle configuration of the three accelerometers in the SIMU, the traditional three-axis orthogonal method is adopted, that is, the sensitive axes of the three accelerometers are installed parallel to the corresponding coordinate axes of the strapdown inertial navigation system.

[0015] A terminal device includes a processor, a memory, and a computer program stored in the memory; when the processor executes the computer program, it implements the design method of the single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope.

[0016] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements the design method of the single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope.

[0017] Compared with the prior art, the present invention has the following technical features: This invention eliminates the cumulative angular rate measurement error caused by ADB (Automatic Deviation in Gyroscope) by mounting the sensitive axis of the hemispherical resonant gyroscope at a specific skew angle to the rotation axis and designing a corresponding single-axis rotation modulation strategy. This ensures that the standing wave angle continuously rotates to integer multiples of 90° during the rotation process, leaving only a scaling factor error proportional to the rotation angle. Compared with traditional installation schemes, this invention has the advantages of simple structure, strong engineering feasibility, and significant modulation effect, significantly improving the long-term navigation accuracy of HRG-based inertial navigation systems in practical applications. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a two-position single-axis rotation modulation inertial navigation system; Figure 2 This is a schematic diagram of short-duration SRINS navigation error in an embodiment of the present invention. Detailed Implementation

[0019] To improve the practical accuracy of HRG-based inertial navigation systems, it is considered to compensate for ADB at the system level, and even further suppress the random constant bias of the gyroscope, which cannot be compensated by self-calibration techniques. Rotation modulation inertial navigation technology is a very common and effective means of reducing the influence of inertial device errors, mainly including three error modulation methods: single-axis rotation, dual-axis rotation, and tri-axis rotation. Single-axis rotation modulation inertial navigation (SRINS) is relatively simple to implement, but rotation around the axial axis can only modulate the constant error of the inertial device in the direction perpendicular to the rotation axis, i.e., the horizontal direction, and cannot eliminate the influence of the constant bias of the axial gyroscope. Dual-axis or tri-axis rotation inertial navigation can theoretically modulate all constant bias errors of the inertial device, but their implementation is relatively complex.

[0020] To address the current issues of large ADB amplitude in HRG, immature self-calibration technology, and difficulty in engineering applications, this invention reduces the impact of ADB at the application level of inertial navigation systems by using a single-axis rotation modulation method. By designing a specific HRG sensitive axis mounting skew angle and a single-axis rotation scheme, the spatially periodically changing ADB zero bias can obtain good modulation compensation, thereby improving the accuracy of HRG inertial navigation.

[0021] This invention provides a design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope, comprising the following steps: Step 1: Construct coordinate systems to provide reference bases for error modeling and rotation modulation.

[0022] In this scheme, the "East-North-Sky (ENU)" coordinate system is selected as the navigation coordinate system, abbreviated as: This is the fundamental reference frame for subsequent inertial navigation calculations; the base coordinate system (or RINS coordinate system) of a single-axis rotating inertial navigation system is defined as follows: The coordinate system, whose coordinate axes are defined as follows: Axis to the right, Axial forward, Axial direction upward (skyward), among which The axis serves as the rotation modulation axis; the coordinate system of the sensitive axes of the three hemispherical resonant gyroscopes is abbreviated as follows: g The coordinate system is a non-orthogonal coordinate system; the inertial sensor coordinate system after orthogonal projection calibration is denoted as... The system, also known as the strapdown inertial measurement unit (SIMU) coordinate system, in which... The axis of rotation of the system shaft and Department The axes coincide. In this scheme, the parameters are indicated by superscripts. express The parameters in one coordinate system are represented in a similar way to those in other coordinate systems.

[0023] Step 2: Establish an ideal model of the standing wave angular rate of the hemispherical resonant gyroscope, construct an angular rate measurement model based on this model, and obtain the angular rate error model by calculating the error; based on the integral characteristics of the angular rate error model, determine the standing wave angular rotation condition that needs to be satisfied under uniform rotation.

[0024] (1) Establish an ideal model of standing wave angular rate.

[0025] The ideal model of the standing wave angular rate of a hemispherical resonant gyroscope is: (1); in: The standing wave angular rate of the hemispherical resonant gyroscope output; The standing wave angle of the hemispherical resonant gyroscope output; This is the scaling factor (standing wave precession coefficient), with a typical value of 0.275; This is the input angular rate of the sensitive axis of the hemispherical resonant gyroscope relative to inertial space; This is the standing wave precession coefficient caused by circumferential drift, i.e., the circumferential zero-bias amplitude, with a typical value of [value missing]. ; The initial azimuth angle of the circumferential zero-bias standing wave. and These are collectively referred to as angle-dependent bias (ADB) parameters.

[0026] (2) Construct an angular rate measurement model.

[0027] Rearranging equation (1) to transform it into an angular rate measurement model: (2); in, The input angular rate is the sensitive axis of the hemispherical resonant gyroscope.

[0028] (3) Establish an angular rate error model.

[0029] Taking the error on both sides of equation (2), we obtain the angular rate error model: (3); in, This refers to the error in angular rate measurement. The standing wave angular rate; This represents the measurement error of the standing wave angular rate; Standing wave angle; This represents the measurement error of the standing wave angle position; Scale factor; This is the scaling factor error; This is the circumferential zero-bias amplitude; For ADB amplitude error; The initial azimuth angle of the circumferential zero-bias standing wave; For ADB phase error; Due to the measurement error of the standing wave angle The equivalent angular rate noise caused by its derivative does not cause cumulative angle measurement error.

[0030] (4) Integral characteristic analysis.

[0031] Note that the second to fourth terms on the right-hand side of equation (3) relate to the standing wave angle. A periodic function; assuming the standing wave angular velocity is constant. And the standing wave angle changes with time Linear change, that is, assuming , The initial standing wave angular velocity; noise is ignored. Then, equation (3) is applied in the standing wave angle interval. (i.e., time interval) , Integrating over integers, we get: (4); Equation (4) shows that if the standing wave angle is uniform and the rotation is continuous, then... For angles (i.e., integer multiples of 90°), the cumulative measurement error of angular rate caused by ADB zero bias is 0, leaving only the scaling factor error, which is proportional to the size of the angle.

[0032] Equation (4) provides the physical conditions that rotation modulation must meet for subsequent steps; only when the standing wave angle rotates exactly an integer multiple during the rotation process can it be achieved. Only then can the ADB error be eliminated in an integral sense. Step 3 is to derive the skew angle based on the conditions of equation (4), so that after the HRG sensitive axis is skewed, the standing wave angle rotates exactly an integer multiple when the SIMU rotates by a certain angle. Step 4: Based on the skew angle configuration in step 3, design specific rotation trajectory, stopping strategy and ADB phase control to ensure that the conditions of equation (4) are continuously met during actual navigation.

[0033] Step 3: Based on the standing wave angle rotation condition, according to the scaling factor of the hemispherical resonant gyroscope, the sensitive axis of each hemispherical resonant gyroscope is installed at an angle to the rotation modulation axis of the base coordinate system, and the value condition of the angle is determined.

[0034] To achieve the ideal modulation conditions in step 2 (standing wave angle rotation multiples of integers) The sensitive axis of the hemispherical resonant gyroscope needs to be installed at an angle to the rotation modulation axis, and the angle of deviation needs to be determined. The conditions for the value of: In traditional single-axis rotational inertial navigation systems based on optical gyroscope SIMUs, the gyroscope's sensing axis is mounted approximately parallel to the SIMU's coordinate axes. The angle at which the SIMU rotates once around the rotation axis is typically... Integer multiples, see Figure 1 However, in a hemispherical resonant gyroscope (SIMU), when the input angular rate of the sensitive axis... The value is much larger than the circumferential zero bias amplitude. At that time, that is Equation (1) can be approximated as To satisfy the standing wave angle rotation condition, even if the standing wave angle rotates one revolution... Then the angle of rotation of the hemispherical resonant gyroscope along the input sensitive axis should be . This value is close to , but not Integer multiples of.

[0035] To achieve the desired rotational modulation effect, the standing wave angle is rotated. For integer multiples of this value, the input sensitive axis of the hemispherical resonant gyroscope needs to be aligned with the rotation modulation axis of the base coordinate system. Shaft) misaligned installation, misalignment angle The following conditions must be met for the value to be taken: (5); Equation (5) indicates that when the SIMU rotates 90° ( When the hemispherical resonant gyroscope rotates at a spatial angle of radians, the standing wave angle of the gyroscope is exactly at the point of rotation. week( (Signal angle in radians); obviously, when the ratio The angle of deviation obtained when they are the same They are the same.

[0036] Set scale factor Table 1 gives some examples of when Deflection angle when all are smaller positive integers Calculated values; those marked with " / " in Table 1 can be referred to other ratios. The same data, for example and They are the same, both are .

[0037] Table 1 provides examples of some deflection angle values.

[0038] Theoretically, the sensitive axis of each hemispherical resonant gyroscope is related to the base coordinate system. The skew angle between the axes can be any value from Table 1; however, in practical applications, it must be ensured that the sensitive axes of the three hemispherical resonant gyroscopes are not coplanar, and preferably installed as perpendicular (or nearly perpendicular) to each other as possible; furthermore, a smaller angle is often chosen. The value is adjusted to achieve error modulation in a shorter time. Specifically, when... At this time, the error modulation effect is not good because the inertial navigation attitude misalignment angle is exactly synchronized with the ADB change cycle. ADB will cause the misalignment angle to accumulate continuously. Therefore, this value should not be used as a candidate value for the installation skew angle.

[0039] Step 4: Based on the completed skew angle configuration, adopt a two-position intermittent single-axis rotation scheme and determine the rotation parameters; set the ADB phase and control strategy for the stopping phase, and determine the installation configuration of the hemispherical resonant gyroscope sensitive axis and accelerometer so that the standing wave angle always meets the standing wave angle rotation condition during the rotation process, thereby eliminating the ADB cumulative error.

[0040] Based on the skew angle configuration in step 3, a single-axis rotation modulation scheme is designed: (1) Rotation trajectory and sequence.

[0041] In a single-axis rotation modulation inertial navigation system (SIMU), three hemispherical resonant gyroscopes revolve around a fixed celestial axis. In designs involving periodic rotations, such as Figure 1 As shown, the base coordinate system The axis points to the sky. shaft and The axis is in the horizontal plane; a two-position intermittent single-axis rotation scheme is adopted: each rotation (or Both the north and south directions are set as the stop positions; the stop duration can be set as needed, for example, setting a relatively long stop time percentage helps reduce the dynamic error of the inertial navigation induced by rotation; this scheme is, in principle, perfectly symmetrical. It should be noted that the so-called "north-south" two stop directions mentioned above do not need to be strictly accurate and fixed during rotation modulation, but can be relatively fixed approximate (within the threshold range) other directions that differ by 90° (or 180°), and even the stop position (direction) can be slowly rotated and changed.

[0042] (2) Rotation parameter selection.

[0043] Select rotation parameters from Table 1 Make it satisfy Integer, can be selected At this point, SIMU rotates 1.5 times. ADB progresses for 1 week ( Or select , .

[0044] (3) ADB phase control.

[0045] During the stopping phase of rotation modulation, the ADB phase of all three hemispherical resonant gyroscopes is set to... (or To maintain the ADB phase synchronization of the three hemispherical resonant gyroscopes, the azimuth angle of the SIMU must be kept in the correct ADB phase during long-term rotational modulation navigation. This helps to reduce the accumulated ADB error. In addition, due to the influence of the celestial component of the Earth's rotation, the SIMU's azimuth angle cannot be continuously rotated relative to a fixed geographic frame in order to maintain the correct ADB phase during the stopping phase. Instead, a free azimuth angle rotation strategy similar to that in a free azimuth inertial navigation system must be adopted, slowly deflecting around the celestial axis so that the equivalent celestial accumulated angle increment output of the SIMU is 0 in each modulation cycle. This is the inertial space rotational modulation of the celestial axis.

[0046] (4) Installation and configuration of the sensitive axes of the three hemispherical resonant gyroscopes.

[0047] Design a coordinate system for the sensitive axes of a three-hemispherical resonant gyroscope. When the three hemispherical resonant gyroscopes are connected to each other (i.e., their sensitive axes are aligned with each other), the system is in operation. The skew angles between the axes are configured to be the same value. Furthermore, the three hemispherical resonant gyroscopes are in the strapdown inertial coordinate system. of The projection on the plane is Uniformly distributed; the unit vector pointing to the three hemispherical resonant gyroscopes can then be solved as follows: remember The unit vector of the sensitive axis of the hemispherical resonant gyroscope is projected onto the strapdown inertial navigation system coordinate system as follows: (6); If Around a unit vector Rotate -120° to get Unit vector of the sensitive axis of the hemispherical resonant gyroscope , and will Around vector Rotate 120° to obtain Unit vector of the sensitive axis of the hemispherical resonant gyroscope That is, and The unit vectors of the gyroscope's sensitive axes are: (7); (8); According to equations (6) and (7), we can calculate that and The angle between the sensitive axes of the hemispherical resonant gyroscope is: (9); This value is also the angle between any two sensitive axes of the three hemispherical resonant gyroscopes; the superscript T in the parameter indicates transpose.

[0048] (5) Installation and configuration of accelerometer.

[0049] Besides the three hemispherical resonant gyroscopes, the installation angle configuration of the three accelerometers in the SIMU can adopt the traditional three-axis orthogonal method, that is, the sensitive axes of the three accelerometers are installed parallel to the corresponding coordinate axes of the strapdown inertial navigation system; alternatively, the sensitive axes of each accelerometer can be configured to be parallel to the sensitive axes of the aforementioned hemispherical resonant gyroscopes. In principle, any installation method of the three accelerometers with non-coplanar three axes is feasible, and in a single-axis rotating inertial navigation system, equivalent random constant zero-point error modulation perpendicular to the rotation axis can be achieved.

[0050] Example: Set the geographical location latitude, longitude, and altitude as follows: L =34°N λ =108°E and h =400m. A two-position single-axis rotary modulation scheme is selected, and the following scheme is adopted from Table 1 ( The HRG is installed with a tilt angle configuration, a rotational angular rate of 18° / s, and a stop time of 60s. The total single-axis rotation for one complete cycle is 4 × (540 / 18 + 60) = 360s. In principle, the two-position SRINS scheme can achieve error modulation of both the HRG's ADB circumferential zero bias and random constant zero bias, as well as error modulation of the accelerometer's random constant bias. Besides the equivalent zero bias perpendicular to the rotation axis, it can also modulate the ADB zero bias parallel to the rotation axis. However, the gyro random constant zero bias and the accelerometer random constant bias parallel to the rotation axis cannot be modulated.

[0051] To verify the modulation effect of the ADB zero bias and accelerometer zero bias of the HRG, we assume that the ADB amplitude of the three HRGs... The initial phases are 0.1° / h, -0.2° / h, and 0.3° / h, respectively. Take respectively , and The random constant bias of the accelerometer is 30. 40 and 50 Without incorporating errors from other inertial devices or initial alignment misalignment angle errors, a pure inertial navigation system (with zero-velocity damping in the azimuth direction) for one Schuler cycle (approximately 5000 s) was simulated. The navigation error is as follows: Figure 2 As shown. From Figure 2 As can be seen, due to the large ADB amplitude setting, during the rotation process of single-axis rotation modulation, Figure 2 (a) Horizontal misalignment angle and Figure 2 (b) Azimuth misalignment angle The fluctuations are relatively large, exceeding 10″ at most, but the error almost returns to zero after each rotation modulation cycle; this is due to the combined effects of the periodic misalignment angle and the accelerometer bias. Figure 2 (c) Horizontal velocity error It exhibits a distinct sawtooth-shaped fluctuation, but there is no significant cumulative growth trend; throughout the navigation process, Figure 2 The maximum positioning error of latitude and longitude of (d) All values ​​are less than 15m, and after one Schuler cycle, they approximately return to zero. Simulation experiments verified the good modulation effect of the ADB zero bias and accelerometer bias error of the hemispherical resonant gyroscope. Even if the ADB zero bias is large, up to the order of 0.3° / h, which is equivalent to the actual gyroscope zero bias of 0.3 / 0.375=0.8° / h, good navigation and positioning results can still be achieved.

[0052] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope, characterized in that, include: Construct coordinate systems to provide reference bases for error modeling and rotation modulation; An ideal model of the standing wave angular rate of a hemispherical resonant gyroscope is established. Based on this, an angular rate measurement model is constructed, and the angular rate error model is obtained by calculating the error. Based on the integral characteristics of the angular rate error model, the standing wave angular rotation condition that needs to be satisfied under uniform rotation is determined. Based on the standing wave angle rotation condition, according to the scaling factor of the hemispherical resonant gyroscope, the sensitive axis of each hemispherical resonant gyroscope is installed at an angle to the rotation modulation axis of the base coordinate system, and the value condition of the angle is determined. Based on the completed skew angle configuration, a two-position intermittent single-axis rotation scheme is adopted, and the rotation parameters are determined; The ADB phase and control strategy for the stopping phase are set, and the installation configuration of the hemispherical resonant gyroscope sensitive axis and accelerometer is determined so that the standing wave angle always meets the standing wave angle rotation condition during the rotation process, thereby eliminating the ADB cumulative error.

2. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, The ideal model of the standing wave angular rate of a hemispherical resonant gyroscope is: ； in: , The standing wave angular rate and standing wave angle are the output values ​​of the hemispherical resonant gyroscope. Scale factor; This is the input angular rate of the sensitive axis of the hemispherical resonant gyroscope relative to inertial space; The precession coefficient of the standing wave caused by circumferential drift; The initial azimuth angle of the circumferential zero-bias standing wave; Rearrange the ideal standing wave angular rate model to transform it into an angular rate measurement model: ； By calculating the errors on both sides of the standing wave angular rate measurement model, we obtain the angular rate error model: ； in, This refers to the error in angular rate measurement. This represents the measurement error of the standing wave angular rate; This represents the measurement error of the standing wave angle position; This is the scaling factor error; For ADB amplitude error; For ADB phase error; Due to the measurement error of the standing wave angle The equivalent angular rate noise caused by its derivative; Assuming the standing wave angular rate is constant And the standing wave angle changes with time Linear change: , The initial standing wave angular rate is given; the equivalent angular rate noise is ignored. Then, the angular rate error model was applied in the standing wave angle range. Integrating, we get: ； If the standing wave angle is uniform and the rotation is continuous, then... For the angle, the cumulative measurement error of the angular rate caused by the ADB zero bias is 0, leaving only the scale factor error, which is proportional to the size of the angle; where It is an integer.

3. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, The input sensitive axis of the hemispherical resonant gyroscope is mounted at an angle to the rotation modulation axis of the base coordinate system, with an angle of skew. The following conditions must be met for the value to be taken: ； in Scale factor; The above formula indicates that when the SIMU rotates... At 90°, the standing wave angle of the hemispherical resonant gyroscope rotates exactly... week; The three hemispherical resonant gyroscopes are not coplanar in their sensitive axes and are installed perpendicular or nearly perpendicular to each other.

4. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, The two-position intermittent single-axis rotation scheme includes: For a single-axis rotationally modulated inertial navigation system, each rotation or Both the north and south directions are set to the stop position; the stop position can also be set to other directions that are 90° or 180° apart.

5. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, The rotation parameters Must meet It is an integer.

6. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, Configure the ADB phase and control strategy during the stopping phase, including: During the stopping phase of rotation modulation, the ADB phase of all three hemispherical resonant gyroscopes is set to... or Or in its vicinity; adopt a free azimuth rotation strategy to slowly deflect around the azimuth axis, so that the equivalent azimuth cumulative angle increment output of the SIMU is 0 in each modulation cycle.

7. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, Determine the installation configuration of the sensitive axis of the hemispherical resonant gyroscope, including: When designing the coordinate system of the sensitive axes of the three hemispherical resonant gyroscopes, the sensitive axes of the three hemispherical resonant gyroscopes are compared with the coordinate system of the strapdown inertial navigation system. The skew angles between the axes are configured to be the same value. Furthermore, the three hemispherical resonant gyroscopes are in the strapdown inertial coordinate system. of The projection on the plane is Uniformly distributed.

8. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 7, characterized in that, The unit vector pointing to the three hemispherical resonant gyroscopes is calculated as follows: remember The unit vector of the sensitive axis of the hemispherical resonant gyroscope is projected onto the strapdown inertial navigation system coordinate system as follows: ； If Around a unit vector Rotate -120° to get Unit vector of the sensitive axis of the hemispherical resonant gyroscope , and will Around vector Rotate 120° to obtain Unit vector of the sensitive axis of the hemispherical resonant gyroscope ; and The angle between the sensitive axes of the hemispherical resonant gyroscope is: ； This value is also the angle between any two sensitive axes of the three hemispherical resonant gyroscopes; the superscript T in the parameter indicates transpose.

9. The design method for a single-axis rotation modulation inertial navigation system based on a hemispherical resonant gyroscope according to claim 1, characterized in that, Determine the installation configuration of the accelerometer, including: For the installation angle configuration of the three accelerometers in the SIMU, the traditional three-axis orthogonal method is adopted, that is, the sensitive axes of the three accelerometers are installed parallel to the corresponding coordinate axes of the strapdown inertial navigation system.

10. A terminal device, comprising a processor, a memory, and a computer program stored in the memory; characterized in that, When the processor executes the computer program, it implements the design method of the single-axis rotation modulation inertial navigation system based on the hemispherical resonant gyroscope as described in any one of claims 1-9.

Images