Underground coal mine directional inclinometry integrated gyro attitude instrument and measurement method

Abstract

The invention discloses an underground coal mine directional inclinometry integrated gyro attitude instrument and a measurement method. The underground coal mine directional inclinometry integrated gyro attitude instrument comprises a shell, a three-axis MEMS gyro, a three-axis MEMS accelerometer, a main control board, a battery module, a communication module, a charging interface, a communication interface, a base, a satellite injection module, a communication cable winch and an orifice handheld end. The small-size structural design is achieved through the MEMS gyroscope and the MEMS accelerometer, the low-power-consumption standby time is long, drilling machine tapping orientation and drilling track measurement can be conducted, the feasibility is high, and the reliability is high; improved initial alignment is adopted, the algorithm comprises coarse alignment and kalman filtering fine alignment, the process comprises data storage calculation and real-time sampling calculation, the alignment time is shortened to the maximum extent, the alignment precision is improved, and meanwhile, full-space high-precision orientation is achieved based on satellite injection parameters; in the process of dynamic tracking in and out of an attitude instrument hole, a communication cable winch is used for controlling the attitude instrument to carry out zero-speed correction, the dynamic accumulative error of the attitude instrument is corrected, and the track measurement precision is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mines and relates to an integrated gyro attitude instrument for underground coal mine orientation and inclinometry and a measurement method. Background Technique

[0002] In order to ensure the quality of underground coal mine boreholes, precise hole opening orientation is required before the drill rig drills, and after the borehole is completed, the hole formation trajectory is measured. Traditional hole opening orientation and trajectory measurement require the use of different instruments, which are costly and complex to operate. At present, gyro sensors are commonly used in underground coal mines for drill rig hole opening orientation. The gyro inertial sensor is not affected by the magnetic interference of the drill rig and can achieve self-seeking north. Single-axis gyroscopes are often used for four-position north seeking in underground gyro hole opening orientation. However, this measurement method requires the inclination angle not to exceed ±15°, and high-precision orientation in the full space cannot be achieved. Therefore, for underground hole opening orientation, north seeking needs to be carried out on a nearly horizontal ground first, and then moved to the drill rig guide rail for hole opening orientation, and the operation is relatively complex. At present, the size of the hole opening orientation instrument is large, and due to sensor and algorithm limitations, in-hole attitude measurement cannot be carried out. At present, magnetic sensors are commonly used for azimuth measurement in underground coal mine in-hole inclinometry, which is easily affected by magnetic interference underground. Even if non-magnetic drill pipes are added, the influence of magnetic interference cannot be completely eliminated. At present, the non-magnetic material is mainly beryllium copper material, which has a high cost and great processing difficulty, bringing potential safety hazards to production safety. At the same time, magnetic in-hole inclinometry basically adopts a point measurement method, with cumbersome operations, seriously affecting work efficiency. Summary of the Invention

[0003] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide an integrated gyro attitude instrument for underground coal mine orientation and inclinometry and a measurement method, realizing a small-size structure design, low power consumption, and long standby time, solving the problem that the traditional drill rig attitude instrument cannot be sent into the hole, being able to carry out drill rig hole opening orientation and fuse the information of the winch encoder to realize borehole trajectory measurement.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to implement:

[0005] An integrated gyro attitude instrument for underground coal mine orientation and inclinometry includes a housing, a three-axis MEMS gyroscope, a three-axis MEMS accelerometer, a main control board, a communication module and a battery module arranged in the housing, a charging interface and a communication interface arranged on the housing, a base, a satellite injection module, a communication cable winch, and a hole mouth handheld terminal;

[0006] The three-axis MEMS gyroscope and the three-axis MEMS accelerometer are orthogonally installed in the housing in three axes, and the main control board is used to collect data and calculate the attitude in real time;

[0007] The bottom of the housing can be installed on the base, and the base can be installed at the drill rig guide rail; the battery module is connected to a three-axis MEMS gyroscope, a three-axis MEMS accelerometer, a main control board, and a communication module for power supply, and is charged through a charging interface at the same time;

[0008] The satellite injection module can write parameters into the attitude instrument;

[0009] The communication cable of the communication cable winch can be connected to the communication interface of the attitude instrument and can also be connected to the hand-held end at the hole opening. When the attitude instrument performs inclinometry in the hole, the encoder of the communication cable winch can record the hole depth information. The inclinometry and depth measurement data are fused to realize the hole trajectory measurement, and are stored and displayed in real time through the hand-held end at the hole opening.

[0010] The present invention further includes the following technical features:

[0011] Specifically, the satellite injection module includes a satellite antenna, a satellite receiver, a solution board, and a communication connection port.

[0012] Specifically, the battery module includes a lithium iron phosphate battery pack and a battery protection module. The lithium iron phosphate battery pack contains 12 cylindrical battery cells and is packaged into a cylindrical shape with an ultra-thin heat shrink film; the battery protection module includes a two-stage voltage stabilization and current limiting circuit. After the lithium iron phosphate battery pack is subjected to two-stage voltage stabilization and current limiting, it is converted into an intrinsically safe power supply output of 8V, 5V, and 3.3V to supply power to the three-axis MEMS gyroscope, the three-axis MEMS accelerometer, the main control board, and the communication module.

[0013] Specifically, the communication module includes isolated RS232, isolated RS485, and diode protection.

[0014] The improved initial alignment method of the integrated gyro attitude instrument for directional inclinometry in coal mines. The process of this method is as follows: after the attitude instrument is powered on, it enters the standby state and judges the data. If it is in a static state, it starts to enter the alignment process. During the alignment process, the original data of the MEMS sensor is stored throughout the process. Coarse alignment is performed using all the data from 0 to 30 s. While calculating the data, the MEMS sensor sampling and storage continue; when the coarse alignment is completed, the kalman filter fine alignment process is started. The result of the coarse alignment is used as the initial value, and the stored data is used to perform filtering calculations starting from 0 seconds until the current sampling moment is calculated and then real-time sampling calculations are performed. Finally, the fine alignment calculation is completed at the moment when the alignment requirements are met.

[0015] Specifically, in the coarse alignment process, the analytical method is first used for coarse alignment, and the double-vector attitude determination algorithm is used. According to the parameters of the satellite injection module, two natural reference quantities of the earth are used:

[0016]

[0017] In Equation (1), g is the acceleration due to gravity, and g n is the projection of the acceleration due to gravity in the navigation coordinate system. ω ie is the angular velocity of the Earth's rotation, is the projection of the angular velocity of the Earth's rotation in the navigation coordinate system, and L is the latitude, which is a satellite injection parameter. Then, the measurement relationship between specific force and angular velocity in the coarse alignment stationary state is expressed as:

[0018]

[0019] In Equation (2), is the attitude transformation matrix, represents the specific force output of the MEMS accelerometer in the body coordinate system, represents the angular velocity output of the MEMS gyroscope in the body coordinate system. Select -g n as the main reference vector. According to the double-vector attitude determination principle, the attitude matrix estimation is expressed as:

[0020]

[0021] In Equation (3), the satellite injection parameter is used to correct According to the output of the MEMS gyroscope and the output of the MEME accelerometer the attitude matrix can be estimated, and thus the inclination angle and azimuth angle can be calculated. Assume that there is an alignment error angle between the estimated attitude matrix and the true attitude matrix Based on the above results of coarse alignment, error analysis is carried out:

[0022]

[0023] In Equation (5), is the output error of the northward MEMS accelerometer, is the output error of the eastward MEMS accelerometer, is the output error of the eastward MEMS gyroscope, and ω N is the northward component of the angular velocity of the Earth's rotation. The above completes the estimation of coarse alignment and alignment error angle.

[0024] Specifically, in the Kalman filter fine alignment process, the alignment error angle is used as the initial value of the Kalman filter to filter and correct the results of coarse alignment, and only the attitude and the velocity v n are updated:

[0025]

[0026] Establish the error propagation equation and the state space model simultaneously:

[0027]

[0028] In Equation (7), ε n is the constant drift of the MEMS gyroscope, is the constant zero bias of the MEMS accelerometer. In Equation (8), G is the noise driving matrix, w is the process noise vector, and V is the measurement noise vector:

[0029]

[0030]

[0031] In Equation (9), are the east misalignment angle, north misalignment angle, and vertical misalignment angle respectively. δv E , δv N are the east velocity error and north velocity error respectively. ε E , ε N , ε U are the constant drifts of the three-axis gyroscope. is the zero bias of the east and north accelerometers. Through the misalignment angle of the rough alignment and the stored data of the MEMS gyroscope and MEMS accelerometer, the filtering calculation is carried out starting from 0 seconds until the real-time sampling calculation is performed after the current sampling moment, and the fine alignment is completed when the alignment requirement moment is reached.

[0032] For the dynamic tracking method of the integrated gyro attitude instrument for underground coal mine orientation and inclinometry, during the dynamic tracking process, first use the multi-sample sampling calculation of the MEMS gyroscope output to calculate the equivalent rotation vector, compensate for the non-commutativity error of rotation, and then use the equivalent rotation vector to calculate the attitude to update the quaternion, and dynamically solve the inclination angle and azimuth angle of the attitude instrument in real time. The communication cable winch encoder records the hole depth information, and the inclinometry and depth measurement data are fused to realize the hole trajectory measurement.

[0033] Specifically, during the dynamic tracking process, since the long-term quaternion update of the MEMS gyroscope will accumulate errors and cause the divergence of attitude solution, therefore, every once in a while, the attitude instrument is stationary, and an instruction is input at the handheld end at the hole mouth. The main control board performs a 30s zero-velocity correction, uses the kalman filter to establish the error equation and the measurement equation, takes the velocity as the observable quantity, so as to estimate the velocity error, position error, and attitude angle error of the system, and compensates the error into the corresponding variables to correct the long-term cumulative error of the gyroscope.

[0034] The measurement method of the integrated gyro attitude instrument for underground coal mine orientation and inclinometry includes the following steps:

[0035] Step 1: Before using the attitude instrument for the first time, in an outdoor open area of this region, connect the attitude instrument to the satellite injection module, inject new parameters, and turn off the instrument after configuration is completed.

[0036] Step 2: Take the attitude instrument to the position where the hole is to be opened underground, install the base at the drill rig guide rail, align the bottom of the attitude instrument housing with the card slot and place it on the base, and perform initial alignment when powering on in a stationary state.

[0037] Step 3: After orientation is completed, adjust the drill rig angle to the predetermined position. The attitude instrument dynamically tracks the attitude angle to provide a data reference for the drill rig adjustment. After the hole opening orientation is completed, turn off the attitude instrument.

[0038] Step 4: After the drilling is completed, connect the attitude instrument to the communication cable winch, connect the communication cable to the hand-held end at the hole opening, power on and perform initial alignment to find the north. After completion, push it to the bottom of the hole at a uniform and slow speed through the hole crawler and hollow push rod methods. The attitude instrument performs dynamic quaternion calculation for in-hole inclination measurement. The communication cable winch encoder records the hole depth information, and the inclination measurement and depth measurement data are fused to achieve in-hole trajectory measurement; when the crawler is sent in, every 15 minutes, the crawler stops for 30 seconds, and the zero-velocity correction is used to compensate for the cumulative error of the attitude instrument. When the push rod is sent in, after each connection of the push rod, it remains stationary for 30 seconds, and the zero-velocity correction is used to correct the error.

[0039] Step 5: After the attitude instrument reaches the bottom of the hole, control the attitude instrument to perform initial alignment by the hand-held end. After the initial alignment is completed, start the winch to slowly retract the attitude instrument at a uniform speed. During the process, the attitude instrument dynamically tracks and measures, and real-time plots the drilling trajectory; every 15 minutes, the winch stops for 30 seconds, and the attitude instrument performs zero-velocity correction to automatically correct the cumulative error of the gyro.

[0040] Step 6: After the attitude instrument is taken out of the drill hole and the measurement is completed, compare the in-hole trajectory measurement data when sent in and the trajectory measurement data when taken out, and turn off the instrument.

[0041] Compared with the prior art, the present invention has the following technical effects:

[0042] The present invention uses MEMS gyroscopes and MEMS accelerometers to achieve a small-size structural design, low power consumption, and a long standby time. It can be used for both drill rig hole opening orientation and integrate the information of the winch encoder to achieve drilling trajectory measurement, realizing two functions with one instrument.

[0043] The present invention uses the base to quickly install the attitude instrument at the drill rig guide rail to achieve hole opening orientation. The attitude instrument is sent into the hole through methods such as the hole crawler or hollow push rod, and the attitude instrument is taken out through the communication cable winch to achieve repeated measurement and verification of the in-hole trajectory. The operation is convenient, the feasibility is high, and the reliability is strong.

[0044] The present invention adopts an improved initial alignment method, which includes coarse alignment and Kalman filter fine alignment in terms of algorithms, and data storage calculation and real-time sampling calculation in terms of processes. This method minimizes the alignment time and improves the alignment accuracy. At the same time, based on satellite injection parameters, high-precision orientation in the whole space can be achieved.

[0045] During the dynamic tracking process of sending the attitude instrument of the present invention into and out of the hole, the communication cable winch is used to control the attitude instrument to perform zero velocity update (ZUPT) to correct the dynamic cumulative error of the attitude instrument and improve the trajectory measurement accuracy. Brief Description of the Drawings

[0046] Figure 1 It is a schematic diagram of the overall structure of an integrated gyro attitude instrument for underground coal mine orientation and inclinometry.

[0047] The meanings of the various reference numerals in the figure are as follows:

[0048] 1. Outer shell, 2. Triaxial MEMS gyroscope, 3. Triaxial MEMS accelerometer, 4. Main control board, 5. Battery module, 6. Charging interface, 7. Communication interface, 8. Base, 9. Satellite injection module, 10. Communication cable winch, 11. Handheld end at the hole opening, 12. Communication module. Detailed Embodiments

[0049] The present invention provides an integrated gyro attitude instrument for underground coal mine orientation and inclinometry and a measurement method. By using a MEMS gyroscope and a MEMS accelerometer, a small-size structural design, low power consumption, and long standby time are achieved, solving the problem that traditional drill rig attitude instruments cannot be sent into the hole. It can be used for drill hole opening orientation and can also integrate the information of the winch encoder to achieve drill hole trajectory measurement, realizing two functions with one instrument. The attitude instrument can be quickly installed on the drill rig guide rail through the base for opening orientation. The attitude instrument is sent into the hole through a hole crawler or a hollow push rod, etc., and is pulled out through the communication cable winch to realize repeated measurement and verification of the hole trajectory. It is convenient to operate, highly feasible, and reliable. It adopts an improved initial alignment method, which includes coarse alignment and Kalman filter fine alignment in terms of algorithms, and data storage calculation and real-time sampling calculation in terms of processes. This method minimizes the alignment time and improves the alignment accuracy. At the same time, based on satellite injection parameters, high-precision orientation in the whole space can be achieved. During the dynamic tracking process of sending the attitude instrument into and out of the hole, the communication cable winch is used to control the attitude instrument to perform zero velocity update (ZUPT) to correct the dynamic cumulative error of the attitude instrument and improve the trajectory measurement accuracy.

[0050] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of this application fall within the protection scope of the present invention.

[0051] Embodiment 1:

[0052] As Figure 1 shown, this embodiment provides an integrated gyro attitude instrument for directional inclinometry in underground coal mines, which includes a housing 1, a three-axis MEMS gyro 2, a three-axis MEMS accelerometer 3, a main control board 4, a communication module 12, and a battery module 5 arranged inside the housing 1, a charging interface 6 and a communication interface 7 arranged on the housing 1, a base 8, a satellite injection module 9, a communication cable winch 10, and a hole mouth handheld terminal 11.

[0053] The three-axis MEMS gyro 2 and the three-axis MEMS accelerometer 3 are orthogonally installed in the housing 1 in three axes, and the main control board 4 is used to collect data and calculate the attitude in real time.

[0054] The bottom of the housing 1 can be installed on the base 8, and the base 8 can be installed at the drill rig guide rail; the battery module 5 is connected to the three-axis MEMS gyro 2, the three-axis MEMS accelerometer 3, the main control board 4, and the communication module 12 for power supply, and is also connected to the charging interface 6 for charging.

[0055] The satellite injection module 9 can write parameters into the attitude instrument; in order to achieve full attitude fast and high-precision measurement, the main control board improves the traditional north-seeking method based on the satellite injection parameters.

[0056] The communication cable of the communication cable winch 10 can be connected to the communication interface 7 of the attitude instrument and can also be connected to the hole mouth handheld terminal 11. When the attitude instrument performs in-hole inclinometry, the communication cable winch encoder can record the hole depth information, and the inclinometry and depth measurement data are fused to realize the in-hole trajectory measurement, and are stored and displayed in real time through the hole mouth handheld terminal 11.

[0057] The satellite injection module 9 includes a satellite antenna, a satellite receiver, a solution board, and a communication connection port.

[0058] The battery module 5 includes a lithium iron phosphate battery pack and a battery protection module. The lithium iron phosphate battery pack contains 12 cylindrical battery cells and is encapsulated in a cylindrical shape with an ultra-thin heat shrink film; the battery protection module includes a two-stage voltage stabilization and current limiting circuit. After the lithium iron phosphate battery pack is subjected to two-stage voltage stabilization and current limiting, it is converted into an intrinsically safe power supply output of 8V, 5V, and 3.3V to supply power to the three-axis MEMS gyro 2, the three-axis MEMS accelerometer 3, the main control board 4, and the communication module 12.

[0059] The communication module 12 includes isolated RS232, isolated RS485, and diode protection.

[0060] The present invention also provides an improved initial alignment method for an integrated gyro attitude instrument for directional inclinometry underground in coal mines. The improved initial alignment adopts a method combining multiple alignment methods and processes. In terms of algorithms, it includes two methods: coarse alignment and Kalman filter fine alignment. In terms of processes, it includes data storage calculation and real-time sampling calculation. This method can minimize the alignment time, improve the alignment accuracy, and at the same time, based on satellite injection parameters, achieve high-precision orientation in the whole space.

[0061] The process of this method is as follows: After the attitude instrument is powered on, it enters the standby state and judges the data. If it is in a stationary state, it starts to enter the alignment process. During the alignment process, the original data of the MEMS sensor is stored throughout. Coarse alignment is performed using all the data from 0 to 30 s. While calculating the data, the MEMS sensor sampling and storage continue. When the coarse alignment ends, the Kalman filter fine alignment process is started. The result of the coarse alignment is used as the initial value, and the stored data is used to perform filtering calculation starting from 0 second until the current sampling moment is calculated, and then real-time sampling calculation is performed. Finally, the fine alignment calculation is completed when the alignment requirement moment is reached.

[0062] In terms of algorithms: In the process of coarse alignment, first, the analytical method is used for coarse alignment. The dual-vector attitude determination algorithm is adopted. According to the parameters of the satellite injection module, two natural reference quantities of the earth are used:

[0063]

[0064] In Equation (1), g is the gravitational acceleration, and g n is the projection of the gravitational acceleration in the navigation coordinate system, ω ie is the earth's angular velocity of rotation, is the projection of the earth's angular velocity of rotation in the navigation coordinate system, and L is the latitude, which is the satellite injection parameter. Then, the measurement relationship of specific force and angular velocity in the stationary state of coarse alignment can be expressed as:

[0065]

[0066] In Equation (2), is the attitude transformation matrix, represents the specific force output of the MEMS accelerometer in the body coordinate system, represents the angular velocity output of the MEMS gyro in the body coordinate system. Select -g n as the main reference vector. According to the dual-vector attitude determination principle, the attitude matrix estimation is expressed as:

[0067]

[0068] In Equation (3), the satellite injection parameter is used to correct According to the output of the MEMS gyro and the MEME accelerometer output the attitude matrix can be realized estimation, so as to calculate the tilt angle and azimuth angle. Assuming the estimated attitude matrix and the true attitude matrix there is an alignment error angle between them According to the results of the above rough alignment, error analysis is carried out:

[0069]

[0070] In formula (5), is the output error of the northward MEMS accelerometer, is the output error of the eastward MEMS accelerometer, is the output error of the eastward MEMS gyroscope, ω N is the northward component of the earth's angular velocity of rotation. The above completes the estimation of the rough alignment and the alignment error angle.

[0071] In the Kalman filter fine alignment process, the alignment error angle is used as the initial value of the Kalman filter to filter and correct the results of the rough alignment. Only the attitude and the velocity v n are updated:

[0072]

[0073] At the same time, an error propagation equation and a state space model are established:

[0074]

[0075]

[0076] In formula (7), ε n is the constant drift of the MEMS gyroscope, is the constant zero bias of the MEMS accelerometer. In formula (8), G is the noise drive matrix, w is the process noise vector, and V is the measurement noise vector:

[0077]

[0078]

[0079] In formula (9), are the eastward alignment error angle, the northward alignment error angle and the vertical alignment error angle respectively, δv E , δv N are the eastward velocity error and the northward velocity error respectively, ε E , ε N , ε U is the constant drift of the three-axis gyroscope are the biases of the eastward and northward accelerometers, and filtering calculations are performed starting from 0 seconds based on the misalignment angle obtained through rough alignment and the stored data of the MEMS gyroscopes and MEMS accelerometers until real-time sampling calculations are performed after the current sampling moment is calculated, and fine alignment is completed when the alignment requirement moment is reached.

[0080] The present invention provides a dynamic tracking method for an integrated gyro attitude instrument for underground coal mine directional inclinometry. During the dynamic tracking process, first, the equivalent rotation vector is calculated by multi-sample sampling of the output of the MEMS gyroscope to compensate for the non-commutable rotation error, and then the equivalent rotation vector is used to calculate the attitude to update the quaternion, and the inclination angle and azimuth angle of the attitude instrument are dynamically and real-timely solved. The encoder of the communication cable winch records the hole depth information, and the inclinometry and depth measurement data are fused to realize the hole trajectory measurement.

[0081] During the dynamic tracking process, since the quaternion update of the MEMS gyroscope will accumulate errors over a long time, resulting in the divergence of attitude calculation, therefore, every once in a while, the attitude instrument is stationary, and an instruction is input at the handheld end at the hole opening. The main control board performs 30s zero velocity correction (ZUPT), uses the Kalman filter to establish the error equation and the measurement equation, takes the velocity as the observable quantity, thereby estimating the velocity error, position error, and attitude angle error of the system, and compensating the errors into the corresponding variables to correct the long-term accumulated errors of the gyroscope.

[0082] A measurement method for an integrated gyro attitude instrument for underground coal mine directional inclinometry, the measurement method comprising the following steps:

[0083] Step 1: Before the attitude instrument is used for the first time, in an outdoor open area of this area, the attitude instrument is connected to the satellite injection module, new parameters are injected, and after the configuration is completed, it is powered off;

[0084] Step 2: Take the attitude instrument to the position where the hole is to be opened underground, install the base at the drill rig guide rail, place the bottom of the attitude instrument housing on the base by aligning it with the card slot, and perform initial alignment in the stationary state and power on;

[0085] Step 3: After the orientation is completed, adjust the angle of the drill rig to the predetermined position. The attitude instrument dynamically tracks the attitude angle to provide a data reference for the adjustment of the drill rig. After the hole opening orientation is completed, the attitude instrument is powered off;

[0086] Step 4: After drilling is completed, connect the attitude instrument to the communication cable winch, connect the communication cable to the handheld end at the orifice, power on and perform initial alignment to find north. After completion, use methods such as the in-hole crawler and the hollow push rod to slowly push it to the bottom of the hole at a uniform speed. The attitude instrument performs dynamic quaternion calculation for in-hole inclinometry. The encoder of the communication cable winch records the hole depth information, and the inclinometry and depth measurement data are fused to achieve in-hole trajectory measurement; when the crawler is sent in, every 15 minutes, the crawler stops for 30 seconds, and the zero velocity update (ZUPT) technology is used to compensate for the cumulative error of the attitude instrument. When the push rod is sent in, after each connection of the push rod, it remains stationary for 30 seconds, and the zero velocity update is used to correct the error;

[0087] Step 5: After the attitude instrument reaches the bottom of the hole, control the attitude instrument to power on and perform initial alignment through the handheld end. After the initial alignment is completed, start the winch to slowly retract the attitude instrument at a uniform speed. During the process, the attitude instrument performs dynamic tracking measurement and real-time plots the drilling trajectory; every 15 minutes, the winch stops for 30 seconds, and the attitude instrument performs zero velocity update to automatically correct the cumulative error of the gyroscope;

[0088] Step 6: After the attitude instrument is taken out of the drill hole and the measurement is completed, compare the in-hole trajectory measurement data when sent in and the trajectory measurement data when taken out, and then power off.

[0089] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0090] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any appropriate manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0091] In addition, any combination can be made between various different embodiments of the present invention as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. An integrated gyro attitude instrument for directional and inclinometric measurement in underground coal mines, characterized in that: It includes a housing, a three-axis MEMS gyroscope arranged in the housing, a three-axis MEMS accelerometer, a main control board, a communication module and a battery module, a charging interface and a communication interface arranged on the housing, a base, a satellite injection module, a communication cable winch, and an orifice handheld terminal; The three-axis MEMS gyroscope and the three-axis MEMS accelerometer are orthogonally installed in the housing, and the main control board collects data and calculates the attitude in real time; The bottom of the housing can be installed on the base, and the base can be installed on the guide rail of the drilling rig; the battery module is connected to the three-axis MEMS gyroscope, the three-axis MEMS accelerometer, the main control board and the communication module for power supply, and is charged through the charging interface at the same time; The satellite injection module can write parameters for the attitude instrument; The communication cable of the communication cable winch can be connected to the attitude meter communication interface and can also be connected to the hole mouth handheld terminal. When the attitude meter performs inclination measurement in the hole, the communication cable winch encoder can record the hole depth information. The inclination measurement and depth measurement data are integrated to realize the hole trajectory measurement, and are stored and displayed in real time through the hole mouth handheld terminal.

2. The integrated gyro attitude instrument for underground coal mine orientation and inclinometer measurement as claimed in claim 1, characterized in that: The satellite injection module includes a satellite antenna, a satellite receiver, a solver board and a communication connection port.

3. The integrated gyro attitude instrument for underground coal mine orientation and inclinometer measurement as claimed in claim 1, characterized in that: The battery module includes a lithium iron phosphate battery pack and a battery protection module. The lithium iron phosphate battery pack contains 12 cylindrical cells and is encapsulated in a cylindrical shape using an ultra-thin heat shrink film; the battery protection module includes a two-stage voltage stabilization and current limiting circuit, which converts the lithium iron phosphate battery pack into 8V, 5V, and 3.3V intrinsically safe power output after two-stage voltage stabilization and current limiting to power the three-axis MEMS gyroscope, three-axis MEMS accelerometer, main control board, and communication module.

4. The coal mine underground directional inclinometer integrated gyro attitude instrument as claimed in claim 1, characterized in that: The communication module includes isolated RS232, isolated RS485 and diode protection.

5. The improved initial alignment method of the integrated gyro attitude instrument for underground coal mine orientation and inclinometer measurement according to any one of claims 1 to 4, characterized in that: The method process is as follows: after the attitude meter is powered on, it enters the standby state and judges the data. If it is in a stationary state, it starts the alignment process. During the alignment process, the original data of the MEMS sensor is stored throughout the process. All data from 0 to 30 seconds are used for rough alignment. While the data is calculated, the MEMS sensor is sampled and stored. When the coarse alignment is completed, the Kalman filter fine alignment process is started, the coarse alignment result is used as the initial value, and the stored data is used to perform filtering calculations starting from 0 seconds until the real-time sampling calculation is performed after the current sampling time is calculated, and finally the fine alignment calculation is completed when the alignment requirement time is reached.

6. The improved initial alignment method of the integrated gyro attitude instrument for underground coal mine orientation and inclinometer measurement as claimed in claim 5, characterized in that: The rough alignment process first adopts the analytical method to perform rough alignment, adopts the dual-vector attitude determination algorithm, and uses two natural earth reference quantities according to the parameters of the satellite injection module: In formula (1), g is the acceleration due to gravity, g n is the projection of gravity acceleration in the navigation coordinate system, ω ie is the Earth's rotation angular velocity, is the projection of the earth's rotation angular velocity in the navigation coordinate system, L is the latitude, and is the satellite injection parameter; the relationship between the specific force and angular velocity measurement in the coarse alignment static state is expressed as: In formula (2), is the attitude transformation matrix, represents the specific force output of the MEMS accelerometer in the carrier coordinate system, Indicates the angular velocity output of the MEMS gyroscope in the carrier coordinate system, select -g n As the main reference vector, according to the principle of double vector attitude determination, the attitude array is estimated It is expressed as: In formula (3), the satellite injection parameter is used to correct According to the MEMS gyro output and MEME accelerometer output Can realize attitude array The inclination and azimuth are calculated by estimating the attitude matrix and the true attitude array There is a misalignment angle According to the above rough alignment results, error analysis is performed: In formula (5), is the north MEMS accelerometer output error, is the east-direction MEMS accelerometer output error, is the east-facing MEMS gyro output error, ω N is the north component of the Earth's rotation angular velocity. The above completes the estimation of the rough alignment and misalignment angle.

7. The improved initial alignment method of the integrated gyro attitude instrument for directional and inclinometric measurement in underground coal mines as claimed in claim 5, characterized in that: The Kalman filter fine alignment process will As the initial value of Kalman filter, the rough alignment result is filtered and corrected. and speed v n To update: At the same time, the error propagation equation and state space model are established: In formula (7), ε n is the MEMS gyro constant drift, is the constant zero bias of the MEMS accelerometer. In equation (8), G is the noise driving matrix, w is the process noise vector, and V is the measurement noise vector: In formula (9), are the east misalignment angle, north misalignment angle and celestial misalignment angle, δv E ,δv N are the eastward velocity error and the northward velocity error, ε E , ε N , ε U is the constant drift of the three-axis gyro, The accelerometer zero bias for the east and north directions is determined by coarse alignment of the misalignment angle The stored MEMS gyroscope and MEMS accelerometer data are filtered and calculated from 0 seconds until the current sampling moment is calculated, and real-time sampling calculation is performed, and the precise alignment is completed when the alignment requirement moment is reached.

8. The dynamic tracking method of the integrated gyro attitude instrument for orientation and inclinometric measurement in underground coal mines according to any one of claims 1 to 4, characterized in that: During the dynamic tracking process, the multi-sub-sample sampling output of the MEMS gyroscope is first used to calculate the equivalent rotation vector to compensate for the non-commutative rotation error. The equivalent rotation vector is then used to calculate the attitude and update the quaternion. The inclination and azimuth of the attitude instrument are dynamically solved in real time. The communication cable winch encoder records the hole depth information. The inclinometer and depth measurement data are fused to realize the in-hole trajectory measurement.

9. The dynamic tracking method of the integrated gyro attitude instrument for directional and inclinometric measurement in underground coal mines as claimed in claim 8, characterized in that: In the dynamic tracking process, the long-term quaternion update of the MEMS gyroscope will accumulate errors and cause the attitude solution to diverge. Therefore, the attitude instrument is stationary at regular intervals, and instructions are input at the port handheld terminal. The main control board performs a 30-second zero-speed correction, and uses the Kalman filter to establish the error equation and measurement equation. The speed is used as the observed quantity to estimate the speed error, position error, and attitude angle error of the system, and the error is compensated to the corresponding variables to correct the long-term accumulated error of the gyroscope.

10. The measuring method of the integrated gyro attitude instrument for orientation and inclination measurement in underground coal mines according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1. Before using the attitude instrument for the first time, connect the attitude instrument to the satellite injection module in an open outdoor area, inject new parameters, and shut down after the configuration is completed; Step 2: Take the attitude meter to the location where the hole is to be drilled underground, install the base on the guide rail of the drilling rig, align the bottom of the attitude meter shell with the card slot and place it on the base, and start the initial alignment in a static state; Step 3: After the orientation is completed, adjust the drilling rig angle to the predetermined position. The attitude meter dynamically tracks the attitude angle to provide a data reference for the drilling rig adjustment. After the hole orientation is completed, the attitude meter is turned off. Step 4. After the drilling is completed, the attitude meter is connected to the communication cable winch, and the communication cable is connected to the handheld terminal at the hole mouth. The machine is initially aligned to find the north. After completion, it is pushed to the bottom of the hole at a uniform and slow speed through the crawler in the hole and the hollow push rod. The attitude meter performs dynamic quaternion solution to measure the inclination in the hole. The communication cable winch encoder records the hole depth information. The inclination measurement and depth measurement data are fused to realize the in-hole trajectory measurement. When the crawler is sent in, the crawler stops for 30 seconds every 15 minutes, and the accumulated error of the attitude meter is compensated by zero-speed correction. When the push rod is sent in, it stays still for 30 seconds after each connection to the push rod, and the error is corrected by zero-speed correction. Step 5: After the attitude meter reaches the bottom of the hole, the handheld terminal is used to control the attitude meter to start the initial alignment. After the initial alignment is completed, the winch is turned on to slowly retract the attitude meter at a uniform speed. During the process, the attitude meter dynamically tracks and measures, and draws the drilling trajectory in real time. Every 15 minutes, the winch stops for 30 seconds, and the attitude meter performs zero-speed correction to automatically correct the gyro cumulative error. Step 6: After the attitude meter is lifted out of the hole, the measurement is completed, and the measurement data of the input drilling trajectory and the measurement data of the lifted trajectory are compared, and the meter is turned off.

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