A method for calibrating the direction of an inertial navigation system for mining

Abstract

The present invention discloses a method for calibrating the direction of an inertial navigation device for use in a mine, and relates to the technical field of calibration of mining navigation devices. The method dynamically adjusts the measurement results of the navigation device by real-time acquisition and analysis of mine environmental data, such as temperature, air pressure, and terrain inclination. By gradually implementing calibration instructions through multiple steps and repeatedly calculating error indexes, the present invention can timely identify and correct errors, and avoid the long-term impact of error accumulation on the navigation system. At the same time, the environmental compensation model established by multi-sensor data fusion and neural network technology enables the system to have stronger environmental adaptability and automatic calibration capabilities. Through real-time data analysis from step one to step five, the present invention simplifies the calibration process, improves the efficiency of calibration, and ensures that the navigation device maintains a high level of navigation accuracy and system stability in a complex mine environment, thereby ensuring the safety and efficiency of mine operations.

Description

Technical Field

[0001] The invention relates to the technical field of calibration of mining navigators, in particular to a method for calibrating the direction of a mining inertial navigator. Background Art

[0002] In modern mine operations, inertial navigation systems (INS) are important positioning and navigation devices, and their accuracy and reliability are crucial to the safety and efficiency of mine operations. However, the complexity of the mine environment and its unique geological and climatic conditions bring many challenges to the operation of inertial navigation systems. These challenges mainly include factors such as temperature changes, air pressure fluctuations, terrain inclination, and environmental interference, which can significantly affect the accuracy of the navigation system.

[0003] In traditional technology, the calibration of inertial navigation systems mostly relies on testing and calibration in a static environment. However, in the actual mine environment, due to the frequent and unpredictable changes in temperature and air pressure in the mine, this static calibration method often cannot cope with the errors caused by dynamic changes. For example, temperature differences and air pressure changes in the mine can cause the sensor of the navigation system to drift, affecting the accuracy of its data. In addition, factors such as terrain inclination and magnetic field interference in the mine may also cause deviations in the attitude calculation of the navigation system, thereby affecting the accuracy of navigation and positioning. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a method for calibrating the direction of an inertial navigation device for mining, so as to solve the problems mentioned in the background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for calibrating the direction of an inertial navigation device for mining, comprising the following steps;

[0006] Step 1: Acquire the initial attitude data of the mining inertial navigator through the inertial measurement unit IMU, establish an initial coordinate system, and mark the initial direction of the navigator based on the initial coordinate system;

[0007] Step 2: Collect mine terrain data, establish a first perception data set, and construct a terrain inclination index Tli based on the first perception data set. If it is higher than a first threshold, send a first preliminary calibration instruction to the outside;

[0008] Step 3: During the operation of the mining inertial navigation system, real-time attitude change data of the navigation system is collected and acquired; the real-time attitude change data includes angular velocity, acceleration, pitch angle, roll angle and heading angle; the real-time attitude change data is compared with the initial attitude data to construct an attitude error data set, and calculation is performed based on the attitude error data set to construct an error index Wczs. When the constructed error index Wczs exceeds the error threshold W, a first warning instruction is generated;

[0009] After receiving the first warning instruction, the mine environment perception data is collected in real time during the operation of the mine inertial navigation system, and a second perception data set is established to construct the magnetic field interference index Mdi, the gravity anomaly index Gai and the reference point deviation index Rpi, and the magnetic field interference index Mdi, the gravity anomaly index Gai, the reference point deviation index Rpi and the error index Wczs are associated to obtain the environmental compensation factor Y;

[0010] Step 4: preset a first compensation threshold value X, and if the environmental compensation factor Y exceeds the first compensation threshold value X, send a second calibration instruction to the outside;

[0011] Step 5. After the second calibration instruction is executed, the temperature and pressure values ​​above and below the mine are collected to construct the temperature difference Cz1 and the pressure difference Cz2. If the temperature difference Cz1 exceeds the temperature compensation threshold, a third calibration instruction is sent to the outside; if the pressure difference Cz2 exceeds the pressure compensation threshold, a fourth calibration instruction is sent to the outside. After the third and fourth calibration instructions are executed, the error index Wczs is recalculated. If the error index Wczs still exceeds the error threshold W, steps 3 to 5 are repeated until the error index Wczs is less than or equal to the error threshold W.

[0012] Preferably, step one comprises:

[0013] S11. Before collecting the initial attitude data, the inertial measurement unit IMU undergoes initialization configuration, including sensor calibration, noise filtering and data synchronization; the inertial measurement unit IMU includes a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer;

[0014] S12, measuring the linear acceleration of the navigator on the x, y, and z axes by a three-axis accelerometer; measuring the angular velocity of the navigator on the x, y, and z axes by a three-axis gyroscope; measuring the direction of the geomagnetic field by a three-axis magnetometer to determine the absolute direction of the navigator;

[0015] S13. Using the initial attitude data, the direction of the navigator at the initial position is calculated through an attitude solution algorithm, and the calculated initial direction is marked in the initial coordinate system as a reference for attitude changes in subsequent operations.

[0016] Preferably, step 2 includes:

[0017] S21. When the navigator is started, the expected initial direction θexpected is set. The setting is the angle relative to the magnetic north direction. θexpected = 0, indicating that the initial direction of the navigator points to the magnetic north. The inertial measurement unit IMU is used to collect the actual direction θmeastured at startup, and the initial deviation Δθinitial is calculated by the following formula:

[0018] Δθinitial=θmeasured-θexpected.

[0019] Preferably, step 2 further comprises:

[0020] S22. Collecting height data of the terrain in the mine area by using LiDAR; the collected height data is represented in the form of a grid or a point cloud, and the heights of different points on the terrain surface are recorded as h(x, y), where h represents the height, and x, y represent the x-axis and y-axis directions respectively;

[0021] S23. Based on the collected terrain height data, the local tilt angle θ(x, y) of each point is calculated by the following formula:

[0022]

[0023] In the formula, and are the slopes of the terrain height h in the x and y directions respectively; arctan represents the inverse tangent function, Δx represents the distance increment in the x direction, and Δy represents the distance increment in the y direction;

[0024] S24. In the entire area, based on the local tilt angle θ(x, y) values ​​at all calculation locations, the terrain tilt index Tli is calculated using the following formula:

[0025]

[0026] Where N is the total number of sampling points; x i and i Respectively represent the position of the i-th sampling point in the x direction and the y direction; is the average value of all local tilt angles;

[0027] S25, comparing the terrain inclination index Tli with the first threshold A to obtain a first evaluation result, including:

[0028] When the terrain inclination index Tli> the first threshold A, it indicates that the terrain condition has an impact risk, and a first preliminary calibration instruction is sent, including: setting a deviation range threshold X, and X is ±1; when the initial deviation amount Δθinitial exceeds the threshold deviation range threshold X, adjustment is required, and the first adjustment amount Δθadjust is calculated by the following formula:

[0029] Δθadjust=-Δθinitial;

[0030] The first adjustment amount is equal to the negative value of the initial offset, which is used to offset the initial offset and make the direction of the navigator consistent with the expected direction;

[0031] When the terrain inclination index Tli≤the first threshold value A, there is no risk of influence from the surface terrain conditions, and the first preliminary calibration is not required.

[0032] Preferably, step three comprises:

[0033] S31. During the operation of the mining inertial navigation system, the pitch angle, roll angle and heading angle data are collected in real time, and the initial pitch angle, roll angle and heading angle data are recorded at startup, and the attitude error is calculated by the following formula: Pitch angle error Δθ p (i) Roll angle error Δθ r (i) and heading angle error Δθ f (i)

[0034]

[0035] In the formula, Δθ p (i) represents the pitch angle error value collected at the i-th time point, Δθ r (i) represents the roll angle error value collected at the i-th time point, Δθ f (i) represents the heading angle error value collected at the i-th time point, θ p (i) represents the pitch angle measured at the i-th time point, represents the initial pitch angle, θ r (i) represents the roll angle measured at the i-th time point, represents the initial roll angle, θ f (i) represents the heading angle measured at the i-th time point, represents the initial heading angle,

[0036] In the formula, the error index Wczs is constructed by the following formula:

[0037]

[0038] Where N represents the total number of sampling points;

[0039] S32, comparing the error index Wczs with the error threshold W to obtain a second evaluation result, including:

[0040] When the error index Wczs>error threshold W, it indicates that the next step of calibration is required, and the first warning instruction is generated, including: the second calibration stage is performed after synchronously collecting the mine environment perception data to measure the impact on the error;

[0041] When the error index Wczs ≤ the error threshold W, it means that the error is within the acceptable range and no calibration is required.

[0042] Preferably, step three also includes:

[0043] S33, after receiving the first warning instruction, synchronously during the operation of the mine inertial navigation system, collecting mine environment perception data in real time to establish a second perception data set;

[0044] The environmental compensation model is established through neural network technology, and an in-depth analysis is performed based on the second perception data set. The magnetic field interference index Mdi, gravity anomaly index Gai and reference point deviation index Rpi are calculated using the following formula:

[0045]

[0046] Where N is the total number of sampling points, B x (i) B y (i) and B z (i) are the components of the magnetic field on the x, y, and z axes measured at the i-th time; and are the stability thresholds of the magnetic field in the x, y, and z axes respectively; g x (i) g y (i) and g z (i) are the components of gravity on the x, y, and z axes measured at the i-th time; d x (i) d y (i) and d z (i) are the components of the deviation relative to the reference point measured at the i-th time in the x, y, and z axes respectively; and are the known values ​​of the reference point on the x, y, and z axes respectively.

[0047] Preferably, step three also includes:

[0048] S34, and correlating the magnetic field interference index Mdi, the gravity anomaly index Gai, and the reference point deviation index Rpi with the error index Wczs to obtain the environmental compensation factor Y;

[0049]

[0050] Wherein, α, β, γ and δ represent the magnetic field interference index Mdi, the gravity anomaly index Gai, the reference point deviation index Rpi and the weight value of the error index Wczs, respectively, and 0<α<1, 0<β<1, 0<γ<1, 0<δ<1, and the specific values ​​are adjusted and set by the user, α+β+γ+δ=1.

[0051] Preferably, step four includes:

[0052] Presetting a first compensation threshold X, and comparing the environmental compensation factor Y with the first compensation threshold X to obtain a third evaluation result, including:

[0053] The environmental compensation factor Y> the first compensation threshold X indicates that the environmental impact is abnormal, and an adjustment of 100-110% is made according to the offset of the error index Wczs;

[0054] If the environmental compensation factor Y ≤ the first compensation threshold X, it indicates that the environmental impact is abnormal, and an 80-90% adjustment is performed according to the offset of the error index Wczs.

[0055] Preferably, step five includes:

[0056] After the second calibration instruction is executed, the temperature and pressure values ​​above and below the mine are collected to obtain the upper temperature value T of the mine. up , the temperature value of the lower part of the mine T down 、The air pressure value Qy in the upper part of the mine up And the air pressure value Qy in the lower part of the mine down ;

[0057] The temperature difference Cz1 and pressure difference Cz2 are calculated by the following formula:

[0058] Cz1=|T up -T down |;

[0059] Cz2=|Qy down -Qy up |.

[0060] Preferably, if the temperature difference Cz1 exceeds the temperature compensation threshold, a third calibration instruction is sent to the outside, including:

[0061] Calculate the temperature compensation application amount Wdyyl:

[0062] Wdyyl=K T *Cz1;

[0063] In the formula, K T It means that every 1℃ change will lead to 0.01 degree direction error; and the current direction of the navigator is corrected according to the temperature compensation application amount Wdyyl;

[0064] If the air pressure difference Cz2 exceeds the air pressure compensation threshold, a fourth calibration instruction is sent to the outside, including:

[0065] Calculate the applied air pressure compensation amount Qyyyl:

[0066] Qyyyl=K Qy *Cz2;

[0067] In the formula, K Qy It means that every 1 hPa change leads to a 0.02 degree direction error; and the current direction of the navigator is corrected according to Qyyyl.

[0068] The present invention provides a method for calibrating the direction of an inertial navigation system for mining, which has the following beneficial effects:

[0069] (1) In the method for calibrating the direction of a mining inertial navigation system, when the terrain inclination index Tli exceeds the first threshold value A, sending a first preliminary calibration instruction can effectively identify and adjust the initial direction deviation caused by terrain changes. This can prevent the influence of terrain inclination on the accuracy of the navigation system. By calculating and applying the first adjustment amount, the system can accurately adjust the initial direction of the navigation system to be consistent with the expected direction, thereby providing an accurate reference for subsequent navigation calculations.

[0070] (2) In a method for calibrating the direction of a mining inertial navigation system, when the environmental compensation factor Y exceeds the first compensation threshold X, the second calibration instruction will be triggered. This can effectively identify the impact of environmental factors on the navigator and compensate for it, thereby improving the system's adaptability to environmental changes. By dynamically adjusting the error compensation strategy (such as 100-110% compensation), the system can make full adjustments under abnormal environmental conditions to ensure that the accuracy of the navigator is not affected by the environment. This calibration mechanism can maintain the stability of the navigator under various environmental conditions, reduce error fluctuations caused by environmental factors, and improve the reliability of the navigation system.

[0071] (3) In this method for calibrating the direction of a mining inertial navigation system, when the temperature difference Cz1 exceeds the temperature compensation threshold, the third calibration instruction can accurately calculate and apply the temperature compensation amount Wdyyl, thereby effectively correcting the direction error caused by temperature changes. Through fine temperature compensation (every 1°C change corresponds to a 0.01 degree direction error), it can be ensured that the navigator can still maintain high-precision direction measurement under temperature fluctuations. Timely adjustment of the navigator's direction to adapt to temperature changes enhances the reliability of the navigation system under extreme temperature conditions.

[0072] (4) In this method for calibrating the direction of a mining inertial navigation system, when the air pressure difference Cz2 exceeds the air pressure compensation threshold, the fourth calibration instruction will be triggered, the air pressure compensation application amount Qyyyl will be calculated, and the direction of the navigation system will be adjusted accordingly to ensure that the air pressure change does not cause the direction error. By compensating the direction error of 0.02 degrees for every 1hPa air pressure change, the direction deviation caused by air pressure fluctuations can be effectively corrected, and the stability of the navigation system in an environment with air pressure changes can be improved. This compensation mechanism ensures that the navigation system can continue to provide accurate direction information when the air pressure changes, maintain navigation accuracy, and ensure the reliability of the system in a changing environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 The present invention is a schematic diagram of the steps of a method for calibrating the direction of an inertial navigation device for mining. DETAILED DESCRIPTION

[0074] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] Example 1, please refer to Figure 1 , the present invention provides a method for calibrating the direction of a mining inertial navigation device, comprising the following steps;

[0076] Step 1: Acquire the initial attitude data of the mining inertial navigator through the inertial measurement unit IMU, establish an initial coordinate system, and mark the initial direction of the navigator based on the initial coordinate system;

[0077] Step 2: Collect mine terrain data, establish a first perception data set, and construct a terrain inclination index Tli based on the first perception data set. If the terrain inclination index Tli is higher than a first threshold, send a first preliminary calibration instruction to the outside.

[0078] Step 3: During the operation of the mining inertial navigation system, real-time attitude change data of the navigation system is collected and acquired; the real-time attitude change data includes angular velocity, acceleration, pitch angle, roll angle and heading angle; the real-time attitude change data is compared with the initial attitude data to construct an attitude error data set, and calculation is performed based on the attitude error data set to construct an error index Wczs. When the constructed error index Wczs exceeds the error threshold W, a first warning instruction is generated;

[0079] After receiving the first warning instruction, the mine environment perception data is collected in real time during the operation of the mine inertial navigation system, and a second perception data set is established to construct the magnetic field interference index Mdi, the gravity anomaly index Gai and the reference point deviation index Rpi, and the magnetic field interference index Mdi, the gravity anomaly index Gai, the reference point deviation index Rpi and the error index Wczs are associated to obtain the environmental compensation factor Y;

[0080] Step 4: Preset a first compensation threshold value X, and if the environmental compensation factor Y exceeds the first compensation threshold value X, send a second calibration instruction to the outside;

[0081] Step 5. After the second calibration instruction is executed, the temperature and pressure values ​​above and below the mine are collected to construct the temperature difference Cz1 and the pressure difference Cz2. If the temperature difference Cz1 exceeds the temperature compensation threshold, a third calibration instruction is sent to the outside; if the pressure difference Cz2 exceeds the pressure compensation threshold, a fourth calibration instruction is sent to the outside. After the third and fourth calibration instructions are executed, the error index Wczs is recalculated. If the error index Wczs still exceeds the error threshold W, steps 3 to 5 are repeated until the error index Wczs is less than or equal to the error threshold W.

[0082] In this embodiment, by real-time collection and processing of mine environment data, such as temperature, air pressure, terrain inclination, etc., the present invention can dynamically adjust the measurement results of the inertial navigation system. Such dynamic calibration can effectively correct the measurement errors caused by environmental changes, thereby significantly improving the positioning accuracy and direction accuracy of the navigation system and ensuring the safety and efficiency of mine operations. The mine environment is complex and changes frequently, and traditional static calibration methods are often difficult to adapt to such dynamic environments. The present invention establishes a comprehensive environmental perception data set, monitors and adjusts the environmental compensation factor in real time, so that the navigation system can effectively adapt to changes in temperature, air pressure and other environmental factors, thereby enhancing the environmental adaptability of the system. By gradually implementing calibration instructions and repeatedly calculating the error index Wczs, the present invention can timely identify and correct errors to avoid the long-term impact of the accumulation of errors on the navigation system. This mechanism ensures the stability and reliability of the navigation system in long-term operation. The method of the present invention reduces the reliance on manual intervention by automatically generating and sending calibration instructions. The system can autonomously detect and adjust the deviation of the navigation system, thereby improving the automation level of the operation and the intelligence level of the system. In traditional technologies, the calibration process may be complicated and time-consuming. The present invention simplifies the calibration process and improves the calibration efficiency through clear steps and real-time data analysis, so that the mining inertial navigation device can quickly respond to environmental changes and maintain a high level of navigation accuracy.

[0083] Example 2: This example is an explanation of Example 1. Specifically, step 1 includes:

[0084] S11. Before collecting the initial attitude data, the inertial measurement unit (IMU) is initialized and configured, including sensor calibration, noise filtering and data synchronization. The inertial measurement unit (IMU) includes a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer. Sensor calibration eliminates system deviations, noise filtering reduces the interference of environmental noise on data, and data synchronization ensures the coordination of data from each sensor. These measures together improve the data reliability of the navigator in a mine environment.

[0085] S12, the linear acceleration of the navigator on the x, y, and z axes is measured by a three-axis accelerometer; the angular velocity of the navigator on the x, y, and z axes is measured by a three-axis gyroscope; the direction of the geomagnetic field is measured by a three-axis magnetometer to determine the absolute direction of the navigator; the linear acceleration data provided by the accelerometer, the angular velocity data of the gyroscope, and the geomagnetic field direction data of the magnetometer provide comprehensive information for calculating the attitude and direction of the navigator. This multi-sensor data fusion method ensures accurate measurement of the navigator's attitude and improves the overall accuracy of the system.

[0086] S13. Using the initial attitude data, calculate the orientation of the navigator at the initial position through the attitude solution algorithm, and mark the calculated initial orientation in the initial coordinate system as a reference for attitude changes in subsequent operations. This reference is crucial for subsequent attitude change analysis, as it provides a stable starting point so that any attitude change can be compared with this reference, thereby accurately identifying and correcting attitude errors.

[0087] In this embodiment, by performing comprehensive sensor configuration and data measurement in the initial stage, step one lays a solid foundation for subsequent dynamic calibration and adjustment. Accurate initial data and reference benchmarks can reduce errors in subsequent calibration processes, thereby improving the efficiency of the entire calibration process.

[0088] Example 3: This example is an explanation of Example 1. Specifically, step 2 includes:

[0089] S21. When the navigator is started, the expected initial direction θexpected is set. The setting is the angle relative to the magnetic north direction. θexpected = 0, indicating that the initial direction of the navigator points to the magnetic north. The inertial measurement unit IMU is used to collect the actual direction θmeastured at startup, and the initial deviation Δθinitial is calculated by the following formula:

[0090] Δθinitial=θmeasured-θexpected.

[0091] Step S21 calculates the initial deviation by setting the expected initial direction and comparing it with the actual direction. This step ensures that the navigator can accurately align with the magnetic north direction when it starts, corrects any deviation caused by inaccurate initial settings, and ensures the accuracy of the navigator's directional basic data. This is crucial for subsequent navigation calculations and avoids systematic errors caused by initial direction deviations.

[0092] S22, collect the height data of the terrain in the mine area by using LiDAR; the collected height data is expressed in the form of a grid or point cloud, and the height of different points on the terrain surface is recorded as h(x,y), where h represents the height, and x and y represent the x-axis and y-axis directions respectively; Step S22 uses LiDAR to collect detailed terrain height data of the mine area. LiDAR can record the height of different points on the terrain surface with high precision and generate detailed grid or point cloud data. These data provide a solid foundation for calculating the terrain inclination angle and conducting more accurate terrain analysis, and improve the understanding and adaptability of mine terrain.

[0093] S23. Based on the collected terrain height data, the local tilt angle θ(x, y) of each point is calculated by the following formula:

[0094]

[0095] In the formula, and are the slopes of the terrain height h in the x and y directions respectively; arctan represents the inverse tangent function, Δx represents the distance increment in the x direction, and Δy represents the distance increment in the y direction;

[0096] S24. In the entire area, based on the local tilt angle θ(x, y) values ​​at all calculation locations, the terrain tilt index Tli is calculated using the following formula:

[0097]

[0098] Where N is the total number of sampling points; x i and i Respectively represent the position of the i-th sampling point in the x direction and the y direction; is the average value of all local tilt angles;

[0099] S25, comparing the terrain inclination index Tli with the first threshold A to obtain a first evaluation result, including:

[0100] When the terrain inclination index Tli> the first threshold A, it indicates that the terrain condition has an impact risk, and a first preliminary calibration instruction is sent, including: setting a deviation range threshold X, and X is ±1; when the initial deviation amount Δθinitial exceeds the threshold deviation range threshold X, adjustment is required, and the first adjustment amount Δθadjust is calculated by the following formula:

[0101] Δθadjust=-Δθinitial;

[0102] The first adjustment amount is equal to the negative value of the initial offset, which is used to offset the initial offset and make the direction of the navigator consistent with the expected direction;

[0103] When the terrain inclination index Tli≤the first threshold value A, there is no risk of influence from the surface terrain conditions, and the first preliminary calibration is not required.

[0104] In this embodiment, steps S23 and S24 accurately evaluate the terrain characteristics of the mine area by calculating the local tilt angle and the terrain tilt index Tli. The calculation of the local tilt angle takes into account the change in terrain height, making the calculation of the terrain tilt index more accurate. This process identifies the possible impact of the terrain on the navigator and provides a quantitative indicator to help evaluate whether further calibration is needed. Step S25 determines whether there is a risk of terrain impact by comparing the terrain tilt index Tli with the first threshold A. If there is an impact risk, a first preliminary calibration instruction is sent and a first adjustment amount is calculated to correct the initial deviation. This dynamic adjustment mechanism ensures that the navigator can be optimized under complex terrain conditions and reduces errors caused by terrain changes. Through the evaluation and adjustment of step S25, the system can perform necessary calibration according to the terrain conditions in actual applications. This method not only improves the adaptability of the system under different terrain conditions, but also reduces unnecessary calibration of the navigator in the preliminary stage, thereby improving the overall calibration efficiency and accuracy.

[0105] Example 4, this example is an explanation of Example 1, specifically, step three includes:

[0106] S31. During the operation of the mining inertial navigation system, the pitch angle, roll angle and heading angle data are collected in real time, and the initial pitch angle, roll angle and heading angle data are recorded at startup, and the attitude error is calculated by the following formula: Pitch angle error Δθ p (i) Roll angle error Δθ r (i) and heading angle error Δθ f (i)

[0107]

[0108] In the formula, Δθ p(i) represents the pitch angle error value collected at the i-th time point, Δθ r (i) represents the roll angle error value collected at the i-th time point, Δθ f (i) represents the heading angle error value collected at the i-th time point, θ p (i) represents the pitch angle measured at the i-th time point, represents the initial pitch angle, θ r (i) represents the roll angle measured at the i-th time point, represents the initial roll angle, θ f (i) represents the heading angle measured at the i-th time point, Indicates the initial heading angle. This real-time monitoring capability allows the system to instantly detect attitude deviations during the operation of the navigator, thereby making timely corrections to the errors and ensuring the accuracy and stability of the navigation data.

[0109] In the formula, the error index Wczs is constructed by the following formula:

[0110]

[0111] Where N represents the total number of sampling points;

[0112] S32, comparing the error index Wczs with the error threshold W to obtain a second evaluation result, including:

[0113] When the error index Wczs>error threshold W, it indicates that the next step of calibration is required, and the first warning instruction is generated, including: the second calibration stage is performed after synchronously collecting the mine environment perception data to measure the impact on the error;

[0114] When the error index Wczs ≤ the error threshold W, it means that the error is within the acceptable range and no calibration is required.

[0115] Step S32 can effectively determine whether the current error exceeds the acceptable range by comparing the error index Wczs with the error threshold W. If the error index Wczs exceeds the threshold W, a first warning instruction is generated to prompt the system to further calibrate. This warning mechanism can effectively prevent the impact of errors on the navigation system and ensure that the system takes timely remedial measures when the error exceeds the standard.

[0116] S33, after receiving the first warning instruction, synchronously during the operation of the mine inertial navigation system, collecting mine environment perception data in real time to establish a second perception data set;

[0117] The environmental compensation model is established through neural network technology, and an in-depth analysis is performed based on the second perception data set. The magnetic field interference index Mdi, gravity anomaly index Gai and reference point deviation index Rpi are calculated using the following formula:

[0118]

[0119] Where N is the total number of sampling points, B x (i) B y (i) and B z (i) are the components of the magnetic field on the x, y, and z axes measured at the i-th time; and are the stability thresholds of the magnetic field in the x, y, and z axes respectively; g x (i) g y (i) and g z (i) are the components of gravity on the x, y, and z axes measured at the i-th time; d x (i) d y (i) and d z (i) are the components of the deviation relative to the reference point measured at the i-th time in the x, y, and z axes respectively; and are the known values ​​of the reference point on the x, y, and z axes respectively.

[0120] S34, and correlating the magnetic field interference index Mdi, the gravity anomaly index Gai, and the reference point deviation index Rpi with the error index Wczs to obtain the environmental compensation factor Y;

[0121]

[0122] Wherein, α, β, γ and δ represent the magnetic field interference index Mdi, the gravity anomaly index Gai, the reference point deviation index Rpi and the weight value of the error index Wczs, respectively, and 0<α<1, 0<β<1, 0<γ<1, 0<δ<1, and the specific values ​​are adjusted and set by the user, α+β+γ+δ=1.

[0123] Step 4 includes:

[0124] Presetting a first compensation threshold X, and comparing the environmental compensation factor Y with the first compensation threshold X to obtain a third evaluation result, including:

[0125] The environmental compensation factor Y> the first compensation threshold X indicates that the environmental impact is abnormal, and an adjustment of 100-110% is made according to the offset of the error index Wczs;

[0126] If the environmental compensation factor Y ≤ the first compensation threshold X, it indicates that the environmental impact is abnormal, and an 80-90% adjustment is performed according to the offset of the error index Wczs.

[0127] In this embodiment, the environmental compensation model established by neural network technology can deeply analyze and process the complex environmental data in the second perception data set. The self-learning and adaptability of the neural network enables the model to accurately identify and compensate for various interference factors in the mine environment, such as magnetic field interference, gravity anomaly and reference point deviation. This technology significantly improves the accuracy and efficiency of environmental compensation. By calculating the magnetic field interference index Mdi, the gravity anomaly index Gai and the reference point deviation index Rpi, the system can comprehensively evaluate the impact of the environment on the navigation error. These indicators provide a detailed quantification of different types of environmental factors, which helps to more comprehensively understand and compensate for environmental interference in actual operation. The environmental compensation factor Y is calculated by associating the magnetic field interference index, the gravity anomaly index and the reference point deviation index with the error index Wczs. This factor takes into account the comprehensive impact of multiple environmental factors on the error and provides an accurate basis for further compensation decisions. This comprehensive analysis capability improves the accuracy of environmental compensation and reduces the error caused by environmental changes. In step 4, by presetting the first compensation threshold X and comparing it with the environmental compensation factor Y, the error compensation amount can be dynamically adjusted. When the environmental compensation factor Y exceeds the threshold value X, the system will make a 100-110% adjustment according to the offset of the error index Wczs to ensure full compensation for abnormal environmental conditions; when the environmental compensation factor Y does not exceed the threshold value, the system will make an 80-90% adjustment. This adjustment strategy effectively reduces the negative impact caused by over-compensation while ensuring moderate calibration under normal environmental conditions.

[0128] Example 5: This example is an explanation of Example 1. Specifically, step 5 includes:

[0129] After the second calibration instruction is executed, the temperature and pressure values ​​above and below the mine are acquired through the temperature sensor and the pressure sensor to obtain the upper temperature value T of the mine. up , the temperature value of the lower part of the mine T down 、The air pressure value Qy in the upper part of the mine up And the air pressure value Qy in the lower part of the mine down By collecting temperature and pressure data in the upper and lower parts of the mine, step five can provide detailed temperature and pressure information of the mine environment. These data are the basis for calculating temperature and pressure differences, which helps to accurately evaluate the impact of environmental conditions on the navigator.

[0130] The temperature difference Cz1 and pressure difference Cz2 are calculated by the following formula:

[0131] Cz1=|T up -T down |;

[0132] Cz2=|Qy down -Qyup |. Calculating the temperature difference Cz1 and the pressure difference Cz2 enables real-time monitoring of environmental differences between the upper and lower parts of the mine. This difference calculation helps to identify and quantify the potential impact of temperature and pressure changes on the navigator, so that necessary calibration measures can be taken in a timely manner.

[0133] If the temperature difference Cz1 exceeds the temperature compensation threshold, a third calibration instruction is sent to the outside, including:

[0134] Calculate the temperature compensation application amount Wdyyl:

[0135] Wdyyl=K T *Cz1;

[0136] In the formula, K T It means that every 1℃ change will lead to 0.01 degree direction error; and the current direction of the navigator is corrected according to the temperature compensation application amount Wdyyl;

[0137] If the air pressure difference Cz2 exceeds the air pressure compensation threshold, a fourth calibration instruction is sent to the outside, including:

[0138] Calculate the applied air pressure compensation amount Qyyyl:

[0139] Qyyyl=K Qy *Cz2;

[0140] In the formula, K Qy It means that every 1 hPa change leads to a 0.02 degree direction error; and the current direction of the navigator is corrected according to Qyyyl.

[0141] When the temperature difference Cz1 exceeds the temperature compensation threshold, the system can accurately correct the direction of the navigator according to the temperature change by calculating the temperature compensation application amount Wdyyl. Every 1°C change in the formula corresponds to a 0.01 degree direction error. This meticulous compensation mechanism ensures that the error caused by temperature change is effectively corrected. When the pressure difference Cz2 exceeds the pressure compensation threshold, the system calibrates by calculating the pressure compensation application amount Qyyyl. Every 1hPa pressure change in the formula corresponds to a 0.02 degree direction error. This calculation ensures that the direction deviation caused by pressure change can be accurately compensated. The trigger mechanism of the third and fourth calibration instructions enables the system to respond immediately when it finds that the temperature or air pressure exceeds the threshold. Through this dynamic calibration mechanism, the system can adjust and correct the direction of the navigator in time to ensure the high accuracy and stability of the navigator during actual operation. By making specific compensation adjustments for environmental factors, step five effectively reduces the errors caused by temperature and pressure changes. This improves the reliability of the mine inertial navigation system under extreme environmental conditions, allowing it to maintain high navigation accuracy in complex mine environments.

[0142] The threshold is set to facilitate comparison. The size of the threshold depends on the amount of sample data and the number of bases set by technicians in this field for each group of sample data; as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0143] The above formulas are obtained by collecting a large amount of data for software simulation and selecting a formula that is close to the actual value. The coefficients in the formula are set by technical personnel in this field according to actual conditions. The above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited to this. Any technical personnel familiar with the technical field within the technical scope disclosed by the present invention, according to the technical solution and the inventive concept of the present invention, make equivalent replacement or change, which should be covered within the protection scope of the present invention.

Claims

1. A method for calibrating the direction of a mining inertial navigation system, characterized in that: The steps include: Step 1: Acquire the initial attitude data of the mining inertial navigation system through the inertial measurement unit IMU, establish an initial coordinate system, and mark the initial direction of the navigation system according to the initial coordinate system; Step 2: Collect mine terrain data, establish a first perception data set, and construct a terrain inclination index Tli based on the first perception data set. If the terrain inclination index Tli is higher than a first threshold, send a first preliminary calibration instruction to the outside. Step 3: During the operation of the mining inertial navigation system, collect and obtain the real-time attitude change data of the navigation system; Real-time attitude change data includes angular velocity, acceleration, pitch angle, roll angle and heading angle; The real-time posture change data is compared with the initial posture data to construct a posture error data set, and calculation is performed based on the posture error data set to construct an error index Wczs. When the constructed error index Wczs exceeds the error threshold W, a first warning instruction is generated; After receiving the first warning instruction, the mine environment perception data is collected in real time during the operation of the mine inertial navigation system, and a second perception data set is established to construct the magnetic field interference index Mdi, the gravity anomaly index Gai and the reference point deviation index Rpi, and the magnetic field interference index Mdi, the gravity anomaly index Gai, the reference point deviation index Rpi and the error index Wczs are associated to obtain the environmental compensation factor Y; Step 4: preset a first compensation threshold value X, and if the environmental compensation factor Y exceeds the first compensation threshold value X, send a second calibration instruction to the outside; Step 5. After the second calibration instruction is executed, the temperature and pressure values ​​above and below the mine are collected to construct the temperature difference Cz1 and the pressure difference Cz2. If the temperature difference Cz1 exceeds the temperature compensation threshold, a third calibration instruction is sent to the outside; if the pressure difference Cz2 exceeds the pressure compensation threshold, a fourth calibration instruction is sent to the outside. After the third and fourth calibration instructions are executed, the error index Wczs is recalculated. If the error index Wczs still exceeds the error threshold W, steps 3 to 5 are repeated until the error index Wczs is less than or equal to the error threshold W.

2. The method for calibrating the direction of a mining inertial navigation system according to claim 1, characterized in that: Step one includes: S11. Before collecting the initial attitude data, the inertial measurement unit IMU undergoes initialization configuration, including sensor calibration, noise filtering and data synchronization; the inertial measurement unit IMU includes a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer; S12, measuring the linear acceleration of the navigator on the x, y, and z axes by a three-axis accelerometer; measuring the angular velocity of the navigator on the x, y, and z axes by a three-axis gyroscope; measuring the direction of the geomagnetic field by a three-axis magnetometer to determine the absolute direction of the navigator; S13. Using the initial attitude data, the direction of the navigator at the initial position is calculated through an attitude solution algorithm, and the calculated initial direction is marked in the initial coordinate system as a reference for attitude changes in subsequent operations.

3. The method for calibrating the direction of a mining inertial navigation system according to claim 1, characterized in that: Step 2 includes: S21. When the navigator is started, the expected initial direction θexpected is set. The setting is an angle relative to the magnetic north direction, that is, θexpected = 0, indicating that the initial direction of the navigator points to the magnetic north. The inertial measurement unit IMU is used to collect the actual direction θmeastured at startup, and the initial deviation Δθinitial is calculated by the following formula: Δθinitial=θmeasured-θexpected.

4. The method for calibrating the direction of a mining inertial navigation system according to claim 1, characterized in that: Step 2 also includes: S22. Collecting height data of the terrain in the mine area by using LiDAR; the collected height data is represented in the form of a grid or a point cloud, and the heights of different points on the terrain surface are recorded as h(x, y), where h represents the height, and x, y represent the x-axis and y-axis directions respectively; S23. Based on the collected terrain height data, the local tilt angle θ(x, y) of each point is calculated by the following formula: In the formula, and are the slopes of the terrain height h in the x and y directions respectively; arctan represents the inverse tangent function, Δx represents the distance increment in the x direction, and Δy represents the distance increment in the y direction; S24. In the entire area, based on the local tilt angle θ(x, y) values ​​at all calculation locations, the terrain tilt index Tli is calculated using the following formula: Where N is the total number of sampling points; x i and i Respectively represent the position of the i-th sampling point in the x direction and the y direction; is the average value of all local tilt angles; S25, comparing the terrain inclination index Tli with the first threshold A to obtain a first evaluation result, including: When the terrain inclination index Tli> the first threshold A, it indicates that the terrain condition has an impact risk, and a first preliminary calibration instruction is sent, including: setting a deviation range threshold X, and X is ±1; when the initial deviation amount Δθinitial exceeds the threshold deviation range threshold X, adjustment is required, and the first adjustment amount Δθadjust is calculated by the following formula: Δθadjust=-Δθinitial; The first adjustment amount is equal to the negative value of the initial offset, which is used to offset the initial offset and make the direction of the navigator consistent with the expected direction; When the terrain inclination index Tli≤the first threshold value A, there is no risk of influence from the surface terrain conditions, and the first preliminary calibration is not required.

5. The method for calibrating the direction of a mining inertial navigation system according to claim 4, characterized in that: Step three includes; S31. During the operation of the mining inertial navigation system, the pitch angle, roll angle and heading angle data are collected in real time, and the initial pitch angle, roll angle and heading angle data are recorded at startup, and the attitude error is calculated by the following formula: Pitch angle error Δθ p (i) Roll angle error Δθ r (i) and heading angle error Δθ f (i) In the formula, Δθ p (i) represents the pitch angle error value collected at the i-th time point, Δθ r (i) represents the roll angle error value collected at the i-th time point, Δθ f (i) represents the heading angle error value collected at the i-th time point, θ p (i) represents the pitch angle measured at the i-th time point, represents the initial pitch angle, θ r (i) represents the roll angle measured at the i-th time point, represents the initial roll angle, θ f (i) represents the heading angle measured at the i-th time point, represents the initial heading angle, In the formula, the error index Wczs is constructed by the following formula: Where N represents the total number of sampling points; S32, comparing the error index Wczs with the error threshold W to obtain a second evaluation result, including: When the error index Wczs>error threshold W, it indicates that the next step of calibration is required, and the first warning instruction is generated, including: the second calibration stage is performed after synchronously collecting the mine environment perception data to measure the impact on the error; When the error index Wczs ≤ the error threshold W, it means that the error is within the acceptable range and no calibration is required.

6. The method for calibrating the direction of a mining inertial navigation system according to claim 1, characterized in that: Step three also includes: S33, after receiving the first warning instruction, synchronously during the operation of the mine inertial navigation system, collecting mine environment perception data in real time to establish a second perception data set; The environmental compensation model is established through neural network technology, and an in-depth analysis is performed based on the second perception data set. The magnetic field interference index Mdi, gravity anomaly index Gai and reference point deviation index Rpi are calculated using the following formula: Where N is the total number of sampling points, B x (i) B y (i) and B z (i) are the components of the magnetic field on the x, y, and z axes measured at the i-th time; and are the stability thresholds of the magnetic field in the x, y, and z axes respectively; g x (i) g y (i) and g z (i) are the components of gravity on the x, y, and z axes measured at the i-th time; d x (i) d y (i) and d z (i) are the components of the deviation relative to the reference point measured at the i-th time in the x, y, and z axes respectively; and are the known values ​​of the reference point on the x, y, and z axes respectively.

7. A method for calibrating the direction of a mining inertial navigation system according to claim 6, characterized in that: Step three also includes: S34, correlating the magnetic field interference index Mdi, the gravity anomaly index Gai, and the reference point deviation index Rpi with the error index Wczs to obtain an environmental compensation factor Y; Where α, β, γ and δ represent the weight values ​​of magnetic field interference index Mdi, gravity anomaly index Gai, reference point deviation index Rpi and error index Wczs, respectively.

8. The method for calibrating the direction of a mining inertial navigation system according to claim 1, characterized in that: Step 4 includes: Presetting a first compensation threshold X, and comparing the environmental compensation factor Y with the first compensation threshold X to obtain a third evaluation result, including: The environmental compensation factor Y> the first compensation threshold X indicates that the environmental impact is abnormal, and an adjustment of 100-110% is made according to the offset of the error index Wczs; If the environmental compensation factor Y ≤ the first compensation threshold X, it indicates that the environmental impact is abnormal, and an 80-90% adjustment is performed according to the offset of the error index Wczs.

9. The method for calibrating the direction of a mining inertial navigation system according to claim 1, characterized in that: Step five includes: After the second calibration instruction is executed, the temperature and pressure values ​​above and below the mine are collected to obtain the upper temperature value T of the mine. up , the temperature value of the lower part of the mine T down 、The air pressure value Qy in the upper part of the mine up And the air pressure value Qy in the lower part of the mine down ; The temperature difference Cz1 and pressure difference Cz2 are calculated by the following formula: Cz1=|T up -T down |; Cz2=|Qy down -Qy up |。 10. A method for calibrating the direction of a mining inertial navigation system according to claim 9, characterized in that: If the temperature difference Cz1 exceeds the temperature compensation threshold, a third calibration instruction is sent to the outside, including: Calculate the temperature compensation application amount Wdyyl: Wdyyl=K T *Cz1; In the formula, K T It means that every 1℃ change will lead to 0.01 degree direction error; and the current direction of the navigator is corrected according to the temperature compensation application amount Wdyyl; If the air pressure difference Cz2 exceeds the air pressure compensation threshold, a fourth calibration instruction is sent to the outside, including: Calculate the applied air pressure compensation amount Qyyyl: Qyyyl=K Qy *Cz2; In the formula, K Qy It means that every 1 hPa change leads to a 0.02 degree direction error; and the current direction of the navigator is corrected according to Qyyyl.

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