Miniaturized single-axis rotation modulation inertial navigation system and rotation method thereof

Abstract

The application provides a miniaturized single-axis rotation modulation inertial navigation system and a rotation method thereof. The system comprises a MEMS inertial measurement unit, a direct drive servo motor, an angle encoder, a conductive slip ring, a navigation solution board, a power supply board, an external interface, a mounting part and a device shell. The rotation method comprises: controlling a rotation mechanism to perform modulation movement according to a double-position four-sequence scheme; constructing a unit vector to perform integration, simulating constant error accumulation; detecting the integral modulus of the vector at half-cycle and integral-cycle time, introducing an additional sequence when the modulus exceeds a threshold, solving the optimal stop position and stop time; and performing the additional sequence to complete adaptive compensation of the carrier angular motion disturbance. The application effectively weakens the influence of the carrier heading motion on the rotation modulation, improves the precision of long-time navigation under motion disturbance, shortens the continuous running time of the rotation mechanism compared with the existing motion isolation scheme, reduces the control complexity, and makes the system more stable.

Description

Technical Field

[0001] This invention belongs to the field of inertial navigation technology and relates to a navigation and positioning device and method for a small carrier, specifically a miniaturized single-axis rotation modulation inertial navigation system and its rotation method. Background Technology

[0002] Strapdown inertial navigation systems (SINS) are a navigation technology that uses inertial sensors to autonomously calculate the motion state of a vehicle. By measuring angular velocity and specific force information in real time using gyroscopes and accelerometers, they autonomously calculate their own position, velocity, and attitude. They can operate independently without relying on external information sources, exhibiting strong autonomy, stealth, and all-weather operation capabilities. Compared to high-precision navigation devices such as fiber optic gyroscopes, MEMS-based strapdown inertial navigation systems offer advantages in cost and size, gradually becoming the mainstream solution for low-cost, small-vehicle navigation and positioning. However, MEMS inertial navigation systems have relatively large error parameters, with the constant errors of gyroscopes and accelerometers being one of the most significant error sources, limiting the accuracy of long-endurance navigation.

[0003] Given the difficulty in improving the accuracy of inertial sensors themselves, sensor error compensation methods have become a key means to improve the accuracy of navigation systems. Rotation modulation technology is an effective way to achieve self-compensation of constant errors in inertial navigation. The Rotation Modulation Inertial Navigation System (RSINS) still uses the strapdown inertial navigation algorithm, but the difference is that the inertial sensor is mounted on a rotation mechanism with an angle measuring device. The rotation mechanism drives the accelerometer and gyroscope to rotate periodically according to certain rules, so that the integral of the constant error of the device in the navigation coordinate system over one period is zero. This can effectively suppress the influence of constant and slowly varying errors such as constant drift of the device on navigation and positioning accuracy.

[0004] During the operation of a rotating inertial navigation system, if the carrier is stationary, the inertial navigation system rotates relative to the navigation system according to a set pattern. However, in reality, the carrier is constantly moving, and the angular motion of the carrier is coupled with the rotational modulation motion, causing the inertial navigation system to rotate relative to the navigation system without following the set pattern. This affects the effect of rotational modulation. In an extreme case, the angular velocity of the carrier relative to the navigation system is exactly equal to and opposite to the angular velocity of the rotational modulation motion. In this case, the error in the navigation system does not change, and the system completely loses the rotational modulation effect, turning into a normal strapdown inertial navigation solution, which leads to a decrease in navigation accuracy. Therefore, it is necessary to isolate the angular motion of the carrier.

[0005] Existing motion isolation algorithms generally utilize carrier attitude data calculated by inertial navigation and a set rotation modulation law to drive the IMU to modulate motion relative to the navigation coordinate system, thus isolating the system from the carrier's angular motion and mitigating its influence. Regarding the issue of carrier angular motion affecting rotation modulation, Honeywell and Sperry proposed a suppression method using calculated IMU attitude data to drive the rotating platform, maintaining a fixed orientation of the IMU relative to the navigation system during the rotation and stopping process. Zhang Lundong et al. proposed a method using the angle value rotated by the axis in inertial space to control the IMU's rotation angle. However, methods involving real-time coordinate system tracking all lead to frequent start-stop of the rotation mechanism. For motors with average performance, the motion isolation effect is poor, and prolonged irregular operation can damage the motor's lifespan and negatively impact system stability.

[0006] Therefore, to address the issue of angular motion interfering with the rotation modulation effect during actual navigation, it is necessary to propose an optimized scheme based on the existing single-axis rotation modulation transposition scheme. This scheme achieves error self-compensation during periodic transposition while isolating the carrier's directional motion. By simulating constant error accumulation through integral calculation, the transposition sequence is adaptively added according to the degree of angular motion interference, and the optimal turning and stopping positions and dwell times are automatically calculated. This reduces the continuous operation time and start-stop frequency of the motor, lowers the dependence of rotation modulation technology on high-precision transposition mechanisms, and improves the lifespan and robustness of navigation equipment. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies and considering the need for angular motion isolation of the carrier in rotation modulation technology, this invention proposes an optimized scheme from the perspective of reducing motor operation frequency and decreasing the probability of failure. This scheme achieves carrier directional motion isolation while performing error self-compensation through periodic rotation. It simulates constant error accumulation through integral calculation, adaptively adds rotation sequence based on the magnitude of angular motion interference, and automatically calculates the optimal rotation and stopping positions and dwell times. This reduces the continuous operation time and start-stop frequency of the motor, lowers the dependence of rotation modulation technology on high-precision rotation mechanisms, and improves the lifespan and robustness of navigation equipment. To achieve the above objectives, this invention provides the following technical solution:

[0008] A miniaturized single-axis rotary modulation inertial navigation system includes a MEMS inertial measurement unit, a direct-drive servo motor, an angle encoder, a motor drive board, a conductive slip ring, a navigation calculation board, a power board, an external interface, mounting components, and a device housing. The MEMS inertial measurement unit outputs acceleration and angular velocity to calculate the attitude, velocity, and position of the carrier, and is directly mounted on the rotating platform of the direct-drive servo motor via connectors.

[0009] The direct-drive servo motor is mounted on a support on the equipment housing, driving the MEMS inertial measurement unit to perform a specific periodic rotation. This modulates part of the inertial navigation error into a periodic signal with zero integral, achieving error self-compensation. The direct-drive method of the motor avoids the backlash error introduced by the reducer, which helps to improve the accuracy of the equipment.

[0010] The angle encoder, used to measure motor rotation angle and speed information, is installed at the bottom of the motor.

[0011] The conductive slip ring provides electrical connection for the MEMS inertial navigation system during rotation. It is mounted on the support of the equipment housing and passes through the hollow ring of the direct drive servo motor. The design is compact and reduces space occupation.

[0012] The navigation calculation board is used to collect MEMS inertial navigation data and encoder angle measurement data, while controlling the rotation of the servo motor, performing strapdown calculation, and finally outputting navigation data. The navigation calculation board is fixed to the housing support by mounting parts.

[0013] The power board is used for voltage conversion and electrical protection, providing multiple power supplies with different voltages, and is fixed to the housing support by mounting brackets;

[0014] The external interface is used for power input and data input / output, and is fixed to the housing support by mounting components;

[0015] The mounting components and the equipment housing are used to install, fix, and protect the various internal components.

[0016] Furthermore, the transposition method includes the following steps:

[0017] S1: After completing the calibration and initial alignment of the equipment, set the initial parameters of the rotation modulation, including the rotation angular velocity ω, the stopping time T, and the residual error integral threshold R. After initialization, navigation begins, and the direct drive motor drives the IMU to rotate periodically according to the dual-position four-sequence rotation scheme, and collects the inertial navigation output data and encoder output data in real time.

[0018] S2: Perform strapdown calculation on the IMU output data to obtain the real-time heading information of the IMU relative to the navigation coordinate system. Based on the heading information, construct a unit vector that rotates with the IMU. Starting from the initial moment, continuously integrate it over time to simulate the accumulation of constant error in the horizontal direction.

[0019] S3: Each time the indexing mechanism is about to reach the 0° position, the magnitude of the vector integral is checked. If it does not exceed the preset threshold, the normal indexing continues according to the dual-position four-sequence method. If it exceeds the threshold, an additional indexing sequence is added. The vector integral is projected onto the carrier coordinate system, and the optimal stopping position and stopping time of the additional indexing sequence are calculated. After the additional sequence is completed, the normal indexing continues. The purpose is to ensure that the inertial navigation system stops at each angle equally within one cycle, thus ensuring the error compensation effect of rotation modulation.

[0020] The two-position four-order transposition scheme described in step S1 includes the following steps:

[0021] S11: The indexing mechanism starts from the initial position 0°, stays for T, rotates 180° clockwise, stays for T, rotates 180° clockwise, and returns to the initial position;

[0022] S12: Change the direction of rotation, starting from the initial position 0°, stay for T, rotate 180° counterclockwise, stay for T, rotate 180° counterclockwise, and return to the initial position. This completes one rotation cycle.

[0023] The aforementioned transposition method is characterized in that the unit vector ε mentioned in step S2... I Fixed to the IMU, with its direction coinciding with the IMU's y-axis, for ease of explanation, it is assumed that the IMU and the carrier coordinate system are initially aligned, and the IMU's y-axis is located at the 0° position of the rotation mechanism. ε I The coordinates in the navigation system are:

[0024] ε I n =[sinψ,cosψ,0]

[0025] Where ψ is the heading angle of the inertial navigation system, ε I n These are the coordinates of the constructed unit vector in the navigation frame, for ε. I n Integrating yields the vector integral E. I n :

[0026]

[0027] Vector integral E I n This reflects the cumulative state of the constant horizontal axis error of the inertial navigation system under the navigation system, for E I n Performing rotation compensation is equivalent to compensating for the cumulative constant error of the horizontal axis of the inertial navigation system.

[0028] Ideally, the carrier has no directional motion. After a periodic stop, the integral of the constant horizontal axial error within one cycle is 0, which should be completely canceled out. Therefore, at the end of step S11 or S12, the vector integral E I n It should be 0. However, in reality, the downloaded body has directional motion, which will disrupt the periodicity of the modulated motion, causing the vector integral value to be non-zero at the end of the period, leaving a residual quantity that has not been canceled.

[0029] The additional sequential steps described in step S3 include:

[0030] S31: When the indexing mechanism rotates to 0°, i.e., returns to the initial position, check the magnitude of the vector integral ||E. I n Whether the preset threshold R is exceeded. If the threshold is not exceeded, the normal transposition continues. If the threshold is exceeded, an extra sequence is added.

[0031] S32: Calculate the optimal stopping position and stopping time for the additional order, with the goal of fully compensating for the remaining uncompensated cumulative constant error at the time of calculation, which is to compensate for the vector integral E. I n To achieve complete compensation of the remaining error within the cycle as much as possible, in the additional sequence, the rotation mechanism is controlled to perform rotational motion relative to the navigation system based on the attitude calculated by the inertial navigation system. The specific steps of this additional sequence are as follows:

[0032] ① Take the nearest direction, which is assumed to be clockwise here. Turn to the calculated optimal angle α according to the set modulation motion angular velocity ω. α is the 0° heading position in the navigation coordinate system relative to the starting time of the extra sequence.

[0033] ②According to the calculation results, the optimal time T to stay at position α is... e ;

[0034] ③ Rotate back to the original position of 0° with the opposite angular velocity -ω, update the zero position of the indexing mechanism to the current position, and the extra sequence is completed, and continue normal indexing.

[0035] Since the rotation of the control indexing mechanism relative to the navigation system is controlled in the additional sequence, α and ω mentioned in the above steps are the position and angular velocity relative to the navigation system. During the process of staying at position α, as well as during the process of rotating to position α and returning to the initial position, the constant error will generate additional integrals. When calculating the optimal position and time, each process needs to be included in the calculation, which can yield the following equation:

[0036]

[0037] Where ψ0 is the inertial navigation heading angle at the calculation time, which is a constant, the following equations can be obtained:

[0038]

[0039] make Solve the equation:

[0040] or

[0041]

[0042] T e >0, α∈(0,2π)

[0043] The calculated T e Let α be the optimal stopping time and α be the optimal stopping heading position. When multiple solutions are found, the solution that minimizes the total time of the extra sequence is prioritized for the rotation movement, i.e.:

[0044]

[0045] Where i = {1, 2}, Let be a set of solutions to the equation.

[0046] An electronic device includes 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 program, it implements the rotation method of the miniaturized single-axis rotation modulation inertial navigation system.

[0047] A computer-readable storage medium storing computer instructions that, when executed by a processor, implement the rotation method of the miniaturized single-axis rotation modulation inertial navigation system.

[0048] Compared with existing technologies, this invention has the following advantages and beneficial effects: The single-axis rotation modulation technology used in this invention achieves self-compensation of the main errors of inertial navigation, improving the long-endurance accuracy of the inertial navigation system; through adaptive threshold detection and additional sequence compensation mechanisms, the system can respond to carrier heading disturbances in real time, significantly improving the error suppression effect in complex motion environments and enhancing navigation anti-interference capabilities; compared with existing carrier angular motion isolation and transposition methods, it reduces the complexity of transposition motor control and the demand for high-precision motors. During navigation, compared with traditional methods, the actual working time of the transposition mechanism is reduced by more than 50%, which can effectively extend the service life of the equipment, reduce power consumption, and make the equipment performance more stable; through threshold detection and additional sequence compensation every half cycle, the influence of carrier angular motion on navigation accuracy is kept within a controllable range, and the angular motion interference is theoretically completely compensated at the end of the additional sequence, resulting in smaller fluctuations and more accurate positioning results. In the most extreme case, the accumulated horizontal constant error due to carrier angular motion does not exceed: Where ε represents the true horizontal constant error vector of the IMU; the device uses MEMS as the inertial measurement unit, and the rotation mechanism is integrated with the motor and electric drive. The overall structure is compact, small in size, low in cost, high in precision and good in stability, giving full play to the advantages of MEMS inertial navigation, and is especially suitable for autonomous navigation and positioning of miniaturized unmanned vehicles for long-term missions. Attached Figure Description

[0049] Figure 1 This is a hardware structure diagram of the miniaturized single-axis rotation modulation inertial navigation system of the present invention;

[0050] Figure 2 This is a structural diagram of the prototype of the miniaturized single-axis rotary modulation inertial navigation system of the present invention;

[0051] Figure 3 This is a schematic diagram of the single-axis indexing scheme provided by the present invention.

[0052] In the diagram: 1. MEMS inertial measurement unit, 2. Direct drive servo motor, 3. Angle encoder, 4. Motor drive board, 5. Conductive slip ring, 6. Navigation calculation board, 7. Power board, 8. External interface, 9. Mounting parts, 10. Equipment housing. Detailed Implementation

[0053] The technical solutions provided by the present invention will be described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0054] Example 1: See Figure 2 This invention provides a miniaturized single-axis rotation modulation inertial navigation system. The system hardware includes: a MEMS inertial measurement unit 1, a direct-drive servo motor 2, an angle encoder 3, a motor drive board 4, a conductive slip ring 5, a navigation calculation board 6, a power supply board 7, an external interface 8, mounting components 9, and a device housing 10.

[0055] The MEMS inertial measurement unit outputs acceleration and angular velocity to calculate the carrier's attitude, velocity, and position, and is directly mounted on the rotating platform of the direct-drive servo motor via a connector.

[0056] The direct-drive servo motor is mounted on a support on the equipment housing, driving the MEMS inertial measurement unit to perform a specific periodic rotation. This modulates part of the inertial navigation error into a periodic signal with zero integral, achieving error self-compensation. The direct-drive method of the motor avoids the backlash error introduced by the reducer, which helps to improve the accuracy of the equipment.

[0057] The angle encoder, used to measure motor rotation angle and speed information, is installed at the bottom of the motor.

[0058] The conductive slip ring provides electrical connection for the MEMS inertial navigation system during rotation. It is mounted on the support of the equipment housing and passes through the hollow ring of the direct drive servo motor. The design is compact and reduces space occupation.

[0059] The navigation calculation board is used to collect MEMS inertial navigation data and encoder angle measurement data, while controlling the rotation of the servo motor, performing strapdown calculation, and finally outputting navigation data. The navigation calculation board is fixed to the housing support by mounting parts.

[0060] The power board is used for voltage conversion and electrical protection, providing multiple power supplies with different voltages, and is fixed to the housing support by mounting brackets;

[0061] The external interface is used for power input and data input / output, and is fixed to the housing support by mounting components;

[0062] The mounting components and the equipment housing are used to install, fix, and protect the various internal components.

[0063] The transposition method control software is built into the navigation calculation board, and specifically includes the following steps:

[0064] S1: After completing the calibration and initial alignment of the equipment, set the initial parameters of the rotation modulation, including the rotation angular velocity ω, the stopping time T, and the residual error integral threshold R. After initialization, navigation begins, and the direct drive motor drives the IMU to rotate periodically according to the dual-position four-sequence rotation scheme, and collects the inertial navigation output data and encoder output data in real time.

[0065] S2: Perform strapdown calculation on the IMU output data to obtain the real-time heading information of the IMU relative to the navigation coordinate system. Based on the heading information, construct a unit vector that rotates with the IMU. Starting from the initial moment, continuously integrate it over time to simulate the accumulation of constant error in the horizontal direction.

[0066] S3: Each time the indexing mechanism is about to reach the 0° position, the magnitude of the vector integral is checked. If it does not exceed the preset threshold, the normal indexing continues according to the dual-position four-sequence method. If it exceeds the threshold, an additional indexing sequence is added. The vector integral is projected onto the carrier coordinate system, and the optimal stopping position and stopping time of the additional indexing sequence are calculated. After the additional sequence is completed, the normal indexing continues. The purpose is to ensure that the inertial navigation system stops at each angle equally within one cycle, thus ensuring the error compensation effect of rotation modulation.

[0067] The two-position four-order transposition scheme described in step S1 includes the following steps:

[0068] S11: The indexing mechanism starts from the initial position 0°, stays for T, rotates 180° clockwise, stays for T, rotates 180° clockwise, and returns to the initial position;

[0069] S12: Change the direction of rotation, starting from the initial position 0°, stay for T, rotate 180° counterclockwise, stay for T, rotate 180° counterclockwise, and return to the initial position. This completes one rotation cycle.

[0070] The transposition method according to claim 2, characterized in that the unit vector ε in step S2 I Fixed to the IMU, with its direction coinciding with the IMU's y-axis, for ease of explanation, it is assumed that the IMU and the carrier coordinate system are initially aligned, and the IMU's y-axis is located at the 0° position of the rotation mechanism. ε I The coordinates in the navigation system are:

[0071] ε I n =[sinψ,cosψ,0]

[0072] Where ψ is the heading angle of the inertial navigation system, ε I n These are the coordinates of the constructed unit vector in the navigation frame, for ε. I n Integrating yields the vector integral E. I n :

[0073]

[0074] Vector integral E I n This reflects the cumulative state of the constant horizontal axis error of the inertial navigation system under the navigation system, for E I n Performing rotation compensation is equivalent to compensating for the cumulative constant error of the horizontal axis of the inertial navigation system.

[0075] Ideally, the carrier has no directional motion. After a periodic stop, the integral of the constant horizontal axial error within one cycle is 0, which should be completely canceled out. Therefore, at the end of step S11 or S12, the vector integral E I n It should be 0. However, in reality, the downloaded body has directional motion, which will disrupt the periodicity of the modulated motion, causing the vector integral value to be non-zero at the end of the period, leaving a residual quantity that has not been canceled.

[0076] The additional sequential steps described in step S3 include:

[0077] S31: When the indexing mechanism rotates to 0°, i.e., returns to the initial position, check the magnitude of the vector integral ||E. I n Whether the preset threshold R is exceeded. If the threshold is not exceeded, the normal transposition continues. If the threshold is exceeded, an extra sequence is added.

[0078] S32: Calculate the optimal stopping position and stopping time for the additional order, with the goal of fully compensating for the remaining uncompensated cumulative constant error at the time of calculation, which is to compensate for the vector integral E. I n To achieve complete compensation of the remaining error within the cycle as much as possible, in the additional sequence, the rotation mechanism is controlled to perform rotational motion relative to the navigation system based on the attitude calculated by the inertial navigation system. The specific steps of this additional sequence are as follows:

[0079] ① Take the nearest direction, which is assumed to be clockwise here. Turn to the calculated optimal angle α according to the set modulation motion angular velocity ω. α is the 0° heading position in the navigation coordinate system relative to the starting time of the extra sequence.

[0080] ②According to the calculation results, the optimal time T to stay at position α is... e ;

[0081] ③ Rotate back to the original position of 0° with the opposite angular velocity -ω, update the zero position of the indexing mechanism to the current position, and the extra sequence is completed, and continue normal indexing.

[0082] Since the rotation of the control indexing mechanism relative to the navigation system is controlled in the additional sequence, α and ω mentioned in the above steps are the position and angular velocity relative to the navigation system. During the process of staying at position α, as well as during the process of rotating to position α and returning to the initial position, the constant error will generate additional integrals. When calculating the optimal position and time, each process needs to be included in the calculation, which can yield the following equation:

[0083]

[0084] Where ψ0 is the inertial navigation heading angle at the calculation time, which is a constant, the following equations can be obtained:

[0085]

[0086] make Solve the equation:

[0087] or

[0088]

[0089] T e >0, α∈(0,2π)

[0090] The calculated T e Let α be the optimal stopping time and α be the optimal stopping heading position. When multiple solutions are found, the solution that minimizes the total time of the extra sequence is prioritized for the rotation movement, i.e.:

[0091]

[0092] Where i = {1, 2}, Let be a set of solutions to the equation.

[0093] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A method for rotating a miniaturized single-axis rotation modulation inertial navigation system, characterized in that, The transposition method includes the following steps: S1: After completing the calibration and initial alignment of the equipment, set the initial parameters of the rotation modulation, including the rotation angular velocity ω, the stopping time T, and the residual error integral threshold R. After initialization, navigation begins, and the direct drive motor drives the IMU to rotate periodically according to the dual-position four-sequence rotation scheme, and collects the inertial navigation output data and encoder output data in real time. S2: Perform strapdown calculation on the IMU output data to obtain the real-time heading information of the IMU relative to the navigation coordinate system. Based on the heading information, construct a unit vector that rotates with the IMU. Starting from the initial moment, continuously integrate it over time to simulate the accumulation of constant error in the horizontal direction. S3: Each time the indexing mechanism is about to reach the 0° position, the magnitude of the vector integral is checked. If it does not exceed the preset threshold, the normal indexing continues according to the dual-position four-sequence method. If it exceeds the threshold, an additional indexing sequence is added. The vector integral is projected onto the carrier coordinate system, and the optimal stopping position and stopping time of the additional indexing sequence are calculated. After the additional sequence is completed, the normal indexing continues. The purpose is to ensure that the inertial navigation system stops at each angle equally within one cycle, thus ensuring the error compensation effect of rotation modulation.

2. The rotation method for a miniaturized single-axis rotation modulation inertial navigation system according to claim 1, characterized in that: The two-position four-order transposition scheme in step S1 includes the following steps: S11: The indexing mechanism starts from the initial position 0°, stays for T, rotates 180° clockwise, stays for T, rotates 180° clockwise, and returns to the initial position; S12: Change the direction of rotation, starting from the initial position 0°, stay for T, rotate 180° counterclockwise, stay for T, rotate 180° counterclockwise, and return to the initial position. This completes one rotation cycle.

3. The rotation method for a miniaturized single-axis rotation modulation inertial navigation system according to claim 2, characterized in that, The unit vector ε in step S2 I Fixed to the IMU, with its direction coinciding with the IMU's y-axis, assuming the IMU and carrier coordinate systems are initially aligned, and the IMU's y-axis is at the 0° position of the rotation mechanism, ε I The coordinates in the navigation system are: e I n =[sinψ,cosψ,0] Where ψ is the heading angle of the inertial navigation system, and ε I n These are the coordinates of the constructed unit vector in the navigation frame, for ε. I n Integrating yields the vector integral E. I n : E I n =∫0 t ε I n dt Vector integral E I n This reflects the cumulative state of the constant horizontal axis error of the inertial navigation system under the navigation system, for E I n Performing rotation compensation is equivalent to compensating for the cumulative constant error in the horizontal axis of the inertial navigation system. Ideally, the carrier has no directional motion. After a periodic stop, the integral of the constant horizontal axial error within one cycle is 0 and should be completely canceled out. When step S11 or S12 ends, the vector integral E I n It should be 0. However, in reality, the download body has directional motion, which will disrupt the periodicity of the modulated motion. As a result, at the end of the period, the vector integral value is not 0, leaving a residual quantity that has not been canceled.

4. The rotation method for a miniaturized single-axis rotation modulation inertial navigation system according to claim 2, characterized in that, The additional sequential steps in step S3 include: S31: When the indexing mechanism rotates to 0°, i.e., returns to the initial position, check the magnitude of the vector integral ||E. I n Whether the preset threshold R is exceeded. If the threshold is not exceeded, the normal transposition continues. If the threshold is exceeded, an extra sequence is added. S32: Calculate the optimal stopping position α and stopping time T for the extra order. e The goal is to completely compensate for the remaining uncompensated cumulative constant error at the time of calculation, which is to compensate for the vector integral E. I n To achieve complete compensation of the remaining error within the cycle as much as possible, in the additional sequence, the rotation mechanism is controlled to perform rotational motion relative to the navigation system based on the attitude calculated by the inertial navigation system. The specific steps of this additional sequence are as follows: ① Take the nearest direction, which is assumed to be clockwise here. Turn to the calculated optimal angle α according to the set modulation motion angular velocity ω. α is the 0° heading position in the navigation coordinate system relative to the starting time of the extra sequence. ②According to the calculation results, the optimal time T to stay at position α is... e ; ③ Rotate back to the original position of 0° with the opposite angular velocity -ω, update the zero position of the indexing mechanism to the current position, and the extra sequence is now complete. Continue with normal indexing. Since the rotation of the control indexing mechanism is relative to the navigation system in the additional sequence, α and ω are the position and angular velocity relative to the navigation system. During the process of staying at position α, as well as during the process of rotating to position α and returning to the initial position, the constant error will generate additional integrals. When calculating the optimal position and time, each process needs to be included in the calculation, resulting in the following equation: Where ψ0 is the inertial navigation heading angle at the calculation time, which is a constant, the following equations can be obtained: make Solve the equation: or T e >0,α∈(0,2π) The calculated T e Let α be the optimal stopping time and α be the optimal stopping heading position. When multiple solutions are found, the solution that minimizes the total time of the extra sequence is prioritized for the rotation movement, i.e.: Where i = {1, 2}, Let be a set of solutions to the equation.

5. A miniaturized single-axis rotary modulation inertial navigation system, characterized in that, A method for implementing the miniaturized single-axis rotation modulation inertial navigation system according to any one of claims 1-4, the system comprising a MEMS inertial measurement unit, a direct-drive servo motor, an angle encoder, a motor drive board, a conductive slip ring, a navigation calculation board, a power board, an external interface, mounting components, and a device housing. Among them, the MEMS inertial measurement unit outputs acceleration and angular velocity, which are used to calculate the carrier's attitude, velocity and position. It is directly mounted on the rotating platform of the direct drive servo motor through the connector. A direct-drive servo motor is mounted on a support on the equipment housing, driving the MEMS inertial measurement unit to perform specific periodic rotations, modulating part of the inertial navigation error into a periodic signal with zero integral. Angle encoders are used to measure motor rotation angle and speed information and are installed at the bottom of the motor; The conductive slip ring provides electrical connection for the MEMS inertial navigation system during rotation. It is mounted on a support on the device housing and passes through the hollow ring of the direct-drive servo motor. The navigation calculation board is used to collect MEMS inertial navigation data and encoder angle measurement data, while controlling the rotation of the servo motor, performing strapdown calculation, and finally outputting navigation data. The navigation calculation board is fixed to the housing support by the mounting parts. The power board is used for voltage conversion and electrical protection, providing multiple different voltage power supplies, and is fixed to the housing support by mounting brackets; The external interface is used for power input and data input / output, and is fixed to the housing support by mounting components; The mounting components and the equipment housing are used to install, fix, and protect the various internal components.

6. 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 program, it implements the rotation method of the miniaturized single-axis rotation modulation inertial navigation system as described in any one of claims 1 to 4.

7. A computer-readable storage medium storing computer instructions thereon, characterized in that: When executed by the processor, the computer instructions implement the rotation method of the miniaturized single-axis rotation modulation inertial navigation system as described in any one of claims 1-4.

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