Mineral small-sized anti-vibration trepanning directional measurement device and method

Abstract

The invention discloses a mining small-sized anti-vibration trepanning directional measurement device and method. The mining small-sized anti-vibration trepanning directional measurement device comprises a battery module, a measurement module, a vibration reduction module, a display module, a power switch and a charging interface, the measurement module comprises an MEMS gyroscope, an MEMS accelerometer, a conductive slip ring, a servo mechanism, an IMU module, a main control board, a motor control board and an external interface connector. Based on the high-precision small-size MEMS gyroscope, the MEMS accelerometer and the integrated small IMU, the equipment size is reduced, the cost is reduced, and the power consumption of the whole machine is reduced; through a four-position north-seeking method, the measurement time is shortened, and high-precision autonomous orientation is realized; based on an integrated small IMU, the tapping direction is updated in real time through quaternion calculation, and dynamic tracking measurement is achieved in the drilling machine adjusting process; according to the vibration reduction module and the vibration reduction method, the vibration resistance problem of an MEMS device is solved, the data quality of an MEMS gyroscope and an MEMS accelerometer is improved, vibration reduction filtering in the tracking process is achieved, and the equipment orientation precision is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mines, and relates to a small-sized vibration-resistant open-hole directional measurement device and method for mine use. Background Art

[0002] In order to ensure the prevention and control of gas and water hazards in coal mines, it is necessary to arrange drill holes before the working face is mined. Usually, it is necessary to accurately measure the opening direction of the drill rig to ensure the quality of the drill holes. In the coal mine underground, by adjusting the angle and direction of the drill rig, accurate control of the drill hole path can be achieved. With the development of drilling technology requirements and directional drilling technology, it is becoming more and more urgent to improve the measurement accuracy of the drill hole opening. The accuracy of the drill hole opening in the coal mine underground will directly affect the quality of the drill hole formation, thus affecting the effects of gas drainage, water exploration and grouting. In the traditional manual measurement method, during the measurement process, the operation is relatively complex and the measurement accuracy is low. At the same time, due to the complex working environment in the coal mine underground, the narrow working space in the mine, the strong electromagnetic interference of large mechanical equipment, and the factors such as high humidity and much dust, the traditional directional technology is difficult to meet the actual underground application conditions. At present, most directional devices use high-precision three-axis fiber optic gyroscopes, which can not only avoid the strong magnetic interference of equipment such as drill rigs, but also achieve high-precision autonomous orientation. However, the three-axis fiber optic gyroscope has a high cost, a large size, high power consumption, and a short standby time of the device, which is difficult to meet the requirements of portability and low cost of underground measurement equipment, increasing the difficulty in the actual promotion process. Therefore, there is an urgent need to develop a small-sized, low-cost, high-precision inertial open-hole directional measurement device to meet the actual engineering needs underground. Summary of the Invention

[0003] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a small-sized vibration-resistant open-hole directional measurement device and method for mine use. Based on a high-precision small-sized MEMS gyroscope, MEMS accelerometer and integrated small-sized IMU, the size of the device is greatly reduced, the cost is lowered, the power consumption of the whole machine is reduced, and the standby time of the device exceeds 20 h. Through the four-position north-seeking method, the measurement time is shortened and high-precision autonomous orientation is achieved. Based on the integrated small-sized IMU, the opening direction is updated in real time through quaternion calculation, and dynamic tracking measurement is realized during the adjustment of the drill rig. At the same time, a vibration damping module and a vibration damping method are proposed to solve the vibration resistance problem of MEMS devices, improve the data quality of the MEMS gyroscope and MEMS accelerometer, realize vibration damping filtering during the tracking process, and improve the orientation accuracy of the device.

[0004] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0005] A small-sized vibration-resistant open-hole directional measurement device for mine use includes a battery module, a measurement module arranged in a housing, a vibration damping module arranged at the bottom of the housing, a display module, a power switch and a charging interface arranged on the side wall of the housing;

[0006] The measurement module includes a MEMS gyroscope, a MEMS accelerometer, a conductive slip ring, a servo mechanism, an IMU module, a main control board, a motor control board, and an external interface connector; the MEMS gyroscope and the MEMS accelerometer are installed on the top of the servo mechanism through the conductive slip ring, the motor control board is installed at the bottom of the servo mechanism, and the main control board and the external interface connector are installed on the housing of the measurement module; the main control board collects the data of the MEMS gyroscope, the MEMS accelerometer, and the IMU module in real time and performs real-time attitude calculation, and the calculation process includes two stages: the north-seeking process and the tracking process.

[0007] The battery module is connected to the charging interface, the measurement module, and the power switch, and includes a 3S4P lithium iron phosphate battery pack.

[0008] The vibration damping module includes a lower screw, an upper nut above it, and a vibration damping spring between the two, and also includes a polyurethane support provided between the lower screw and the upper nut; the polyurethane support has elastic and damping properties and can maintain parallelism through the vibration damping spring, reduce the impact energy, and absorb the high-frequency vibration transmitted from the housing base.

[0009] The present invention further includes the following technical features:

[0010] Specifically, the battery module includes a 3S4P lithium iron phosphate battery pack, which contains 12 cylindrical battery cells. The battery cells are packaged in three rows side by side and are encapsulated with an ultra-thin heat shrink film, with a capacity of 3.6 Ah and a discharge cut-off voltage of ≤ 8.1 V; the battery module is provided with a battery protection board, which has functions of short-circuit protection, over-current protection, over-charge protection, and over-discharge protection.

[0011] Specifically, when installing the vibration damping module, a torque wrench tool is used to ensure that the compression amount values of the vibration damping springs of each vibration damping module are equal; the vibration damping module can absorb the vibration energy of the drill, reduce the bandwidth of the device, isolate the high-frequency vibration of the drill. At the same time, according to the position of the geometric center of the vibration damping module, the installation azimuths of the MEMS gyroscope and the MEMS accelerometer in the measurement module are optimized, the relative distance is reduced, and the installation flatness and orthogonality of the MEMS gyroscope and the MEMS accelerometer are ensured, which can improve the performance of the MEMS gyroscope during the north-seeking process, reduce the dimensional effect and coning drift error caused by jitter, improve the anti-angular vibration performance of the measurement module, and improve the north-seeking accuracy.

[0012] Specifically, the measurement module is connected to a display module, and the display module uses a serial port screen. The displayed data includes azimuth angle, inclination angle, tool face angle, temperature, power, and stored azimuth angle data.

[0013] Measurement method of the small mine anti-vibration hole-opening orientation measurement device. During the north-seeking process, the motor control board controls the servo mechanism to drive the MEMS gyroscope and the MEMS accelerometer to rotate evenly by four angles along the horizontal plane. The main control board collects a set of MEMS gyroscope and MEMS accelerometer data every 90°. The four-position outputs of the MEMS gyroscope and the MEMS accelerometer are ω1, ω2, ω3, ω4, f1, f2, f3, f4 respectively:

[0014]

[0015]

[0016] In the above formula, the constant drift of the MEMS gyroscope is ε0, and the constant zero bias of the MEMS accelerometer is The scale factors of the MEMS gyroscope and the MEMS accelerometer are K g and K a , the angular velocity of the earth's rotation is ω e , the earth's gravitational acceleration is g, the azimuth angle is the inclination angle is θ, the roll angle is γ, and the local latitude is λ;

[0017] Subtract the output of the MEMS gyroscope and the MEMS accelerometer at position 1 from the output at position 3, and subtract the output at position 2 from the output at position 4, then the drift of the MEMS gyroscope, the zero bias of the MEMS accelerometer and the random error can be eliminated, and the azimuth angle and the inclination angle θ can be calculated during the north-seeking process.

[0018] Specifically, during the tracking process, the drilling rig adjusts the angle, and the hole-opening orientation device rotates the azimuth angle along with the drill rig guide rail. The main control board establishes the initial attitude matrix based on the azimuth angle and the inclination angle θ obtained from the north-seeking solution, and continuously collects the data of the IMU module in real time. The initial attitude matrix is updated by measuring the angular rate in the inertial space. Using the quaternion strapdown inertial navigation solution principle, the real-time azimuth angle and the inclination angle θ1 are continuously tracked and updated.

[0019] Specifically, during the tracking process, the IMU module is directly fixed inside the housing, and the tracking anti-vibration is realized by introducing the low-pass filtering method.

[0020] Specifically, during the adjustment process of the drilling rig, the motion bandwidth is in the low-frequency band, and a large amount of vibration signals are in the high-frequency band. Therefore, digital filtering is carried out in the way of a low-pass filter, so as to filter out the high-frequency disturbances and stabilize the system attitude.

[0021] Specifically, a Butterworth low-pass filter is designed. This filter is a low-pass filter with a maximally flat magnitude response. Therefore, it is flat before the cut-off frequency, ensuring the original value of the signal and not being attenuated due to filtering. The cut-off frequency of the designed filter is ω c , which can effectively attenuate vibrations with frequencies above ω c , and truly and effectively retain the low-frequency motion information. The designed filter is in the form of a first-order inertial link, and its continuous form expression is:

[0022]

[0023] where s is a complex frequency variable used to describe the transfer function of a continuous-time system, and τ is the time constant. This parameter is set according to the -3dB cut-off frequency of the first-order low-pass filter, so Therefore:

[0024]

[0025] If the filter is to be implemented, it needs to be discretized. Assuming the sampling time is T, and the bilinear transformation maps the s-domain to the z-domain, then:

[0026]

[0027] Substituting (11) into (10), then:

[0028]

[0029] where K = ω c , Performing a first-order backward difference on the above formula, then:

[0030]

[0031] where y[n] represents the filtered data at the current nth beat, y[n - 1] represents the filtered data at the (n - 1)th beat, u[n] represents the sampled data before filtering at the nth beat, and u[n - 1] represents the sampled data before filtering at the (n - 1)th beat. Thus, a discrete recursive filtering formula in the time domain is formed, and continuous operation is performed to achieve the filtering and anti-vibration effect.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] The hole-opening orientation device of the present invention is installed on the drill rig guide rail, and through the north-seeking and tracking processes, high-precision orientation of the drill rig is achieved.

[0034] Through the four-position north-seeking principle, the present invention eliminates the drift of the MEMS gyroscope, the zero bias and random errors of the MEMS accelerometer, etc., and improves the north-seeking accuracy of hole opening. Through the IMU quaternion strapdown inertial navigation solution principle, the real-time azimuth angle and inclination are continuously updated to achieve high-precision dynamic tracking.

[0035] Through the shock absorption module, the present invention absorbs the impact energy of the drilling rig, isolates high-frequency vibrations, improves the data quality of the MEMS gyroscope during the north-seeking process, and enhances the north-seeking accuracy. Through the low-pass filtering method, vibration damping and filtering of the IMU during the dynamic process are achieved, improving the tracking accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of a high-precision vibration-resistant hole-opening orientation device.

[0037] Figure 2 It is a schematic diagram of the structure of the measurement module.

[0038] Figure 3 It is a schematic diagram of the structure of the shock absorption module.

[0039] Figure 4 It is a schematic diagram of the effect of the shock absorption module filtering out the high-frequency vibrations of the drilling rig.

[0040] Figure 5 It is a schematic diagram of the shock absorption algorithm improving the dynamic tracking effect.

[0041] The meanings of the various reference numerals in the figure are as follows:

[0042] 1. Outer shell, 2. Battery module, 3. Measurement module, 4. Shock absorption module, 5. Display module, 6. Power switch, 7. Charging interface; 31. MEMS gyroscope, 32. MEMS accelerometer, 33. Conductive slip ring, 34. Servo mechanism, 35. IMU module, 36. Main control board, 37. Motor control board, 38. External interface connector; 41. Lower screw, 42. Polyurethane support, 43. Shock absorption spring, 44. Upper nut. DETAILED DESCRIPTION OF THE INVENTION

[0043] The present invention provides a small-sized vibration-resistant hole-opening orientation measurement device and method for mining, which includes a battery module, a measurement module, a display module, a shock absorption module, a power switch, a charging interface, and an outer shell. During the hole-opening orientation measurement process, through the four-position north-seeking principle, the drift of the MEMS gyroscope, the zero bias of the MEMS accelerometer, and random errors are eliminated, improving the hole-opening north-seeking accuracy. Through the IMU quaternion strapdown inertial navigation algorithm, the real-time azimuth and inclination are continuously updated to achieve high-precision dynamic tracking. At the same time, during the drilling rig orientation process, through the shock absorption module, the data quality of the MEMS gyroscope and the MEMS accelerometer in the measurement module is improved, enhancing the north-seeking accuracy. Through the filtering method, vibration damping and filtering during the IMU tracking process are achieved, improving the tracking accuracy of the measurement module.

[0044] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and any equivalent transformation based on the technical solution of this application falls within the protection scope of the present invention.

[0045] Embodiment 1:

[0046] As Figures 1 to 3 shown, this embodiment provides a small-sized mine anti-vibration and hole-opening orientation measuring device, which includes a battery module 2, a measurement module 3 arranged in a housing 1, a vibration damping module 4 arranged at the bottom of the housing 1, a display module 5 arranged on the side wall of the housing 1, a power switch 6, and a charging interface 7.

[0047] The measurement module 3 includes a MEMS gyroscope 31, a MEMS accelerometer 32, a conductive slip ring 33, a servo mechanism 34, an IMU module 35, a main control board 36, a motor control board 37, and an external interface connector 38; the MEMS gyroscope 31 and the MEMS accelerometer 32 are installed on the top of the servo mechanism 34 through the conductive slip ring 33, the motor control board 37 is installed at the bottom of the servo mechanism 34, and the main control board 36 and the external interface connector 38 are installed in the measurement module housing; the main control board 36 collects the data of the MEMS gyroscope 31, the MEMS accelerometer 32, and the IMU module 35 in real time and performs real-time attitude calculation. The calculation process includes two stages: a north-seeking process and a tracking process.

[0048] The battery module 2 is connected to the charging interface 7, the measurement module 3, and the power switch 6, and includes a 3S4P lithium iron phosphate battery pack, 12 cylindrical battery cells. The battery cells are encapsulated in three rows side by side and are encapsulated with an ultra-thin heat shrink film, with a capacity of 3.6 Ah and a discharge cut-off voltage ≤ 8.1 V; the battery module is provided with a battery protection board, which has functions of short-circuit protection, over-current protection, over-charge protection, and over-discharge protection.

[0049] The vibration damping module 4 includes a lower screw 41, an upper nut 44 above it, and a vibration damping spring 43 between the two, and also includes a polyurethane support 42 arranged between the lower screw 41 and the upper nut 44; the polyurethane support 42 has good elasticity and damping performance, and can maintain good parallelism through the vibration damping spring 43, reduce the impact energy, and absorb the high-frequency vibration transmitted from the housing base.

[0050] When installing the vibration damping module, use tools such as torque wrenches to ensure that the compression amounts of the vibration damping springs of each vibration damping module are equal, and avoid the problem of unstable installation caused by excessive compression of a certain vibration damping module. Through the vibration damping module, most of the vibration energy of the drill can be absorbed, reducing the bandwidth of the device and isolating the high-frequency vibration of the drill. At the same time, according to the position of the geometric center of the vibration damping module, optimize the installation orientation of the MEMS gyroscope and MEMS accelerometer in the measurement module, reduce the relative distance, and ensure the flatness and orthogonality of the installation planes of the MEMS gyroscope and MEMS accelerometer, improving the performance of the MEMS gyroscope during the north-seeking process, reducing errors such as size effects and conical drifts caused by jitter, improving the anti-angular vibration performance of the measurement module, and improving the north-seeking accuracy. As Figure 4 The blue curve represents the sampling data of the MEMS gyroscope without the vibration damping module, and the red curve represents the sampling data of the MEMS gyroscope after adding the vibration damping module. It can be seen that the vibration damping module can effectively filter out the high-frequency vibration of the drill.

[0051] The measurement module 3 is connected to the display module 5. The display module 5 uses a serial port screen, and the displayed data includes azimuth angle, inclination angle, tool face angle, temperature, power, and stored azimuth angle data, etc.

[0052] The present invention also provides a measurement method for a small anti-vibration hole-opening orientation measurement device for mining. During the north-seeking process, the motor control board controls the servo mechanism to drive the MEMS gyroscope and MEMS accelerometer to rotate evenly along the horizontal plane by four angles. The main control board collects a set of MEMS gyroscope and MEMS accelerometer data every 90°. The four-position outputs of the MEMS gyroscope and MEMS accelerometer are ω1, ω2, ω3, ω4, f1, f2, f3, f4 respectively:

[0053]

[0054] In the above formula, the constant drift of the MEMS gyroscope is ε0, and the constant zero bias of the MEMS accelerometer is The scale factors of the MEMS gyroscope and MEMS accelerometer are K g and K a , without considering the random error term, the angular velocity of the earth's rotation is ω e , the earth's gravitational acceleration is g, the azimuth angle is the inclination angle is θ, the roll angle is γ, and the local latitude is λ.

[0055] Subtract the output of the MEMS gyroscope and MEMS accelerometer at position 1 from the output at position 3, and subtract the output at position 2 from the output at position 4, then the drift of the MEMS gyroscope, the zero bias of the MEMS accelerometer, and random errors can be eliminated, and the azimuth angle and the inclination angle θ during the north-seeking process can be calculated. The north-seeking azimuth accuracy is significantly better than the traditional three-axis gyroscope alignment accuracy.

[0056] During the tracking process, the drilling rig adjusts its angle, and the hole-opening orientation device rotates the azimuth angle following the drill rig guide rail. The main control board establishes the initial attitude matrix based on the azimuth angle and the inclination angle θ and collects the data of the IMU module in real time. The initial attitude matrix is updated by measuring the inertial space angular rate, and the real-time azimuth angle is continuously tracked and updated using the quaternion strapdown inertial navigation solution principle. and the inclination angle θ1.

[0057] However, during the hole-opening measurement process, since the drilling rig is in the powered-on state, vibration will be transmitted to the guide rail. The MEMS gyroscope, MEMS accelerometer, and IMU module are sensitive to vibration. According to the above method, the error of north-seeking and tracking solution is relatively large. Therefore, to improve the measurement accuracy, vibration resistance needs to be achieved, and a vibration damping module and a vibration damping method are added to this device.

[0058] During the tracking process, the hole-opening orientation device moves along with the drill rig guide rail, and the vibration damping module will affect the accuracy of attitude tracking measurement. Therefore, the IMU module is directly fixed inside the housing of the hole-opening orientation device, and tracking vibration resistance is achieved by introducing the low-pass filtering method.

[0059] Through the analysis of the movement bandwidth of the drilling rig adjustment and the spectrum analysis of the drilling rig vibration, it can be seen that the movement bandwidth during the drilling rig adjustment process is basically in the low-frequency band, and a large amount of vibration signals are in the high-frequency band. Therefore, digital filtering can be carried out in the form of a low-pass filter to achieve the effect of filtering out high-frequency disturbances and stabilizing the system attitude.

[0060] Design a Butterworth low-pass filter. This filter is a low-pass filter with the maximum flat amplitude response. Therefore, it is relatively flat before the cut-off frequency, and this flatness also ensures the original value of the signal and will not be attenuated due to filtering; design the cut-off frequency of the filter to be ω c , which can effectively attenuate the vibration frequency above ω c , and truly and effectively retain the low-frequency movement information; design the filter form as a first-order inertial link, and its continuous form expression is:

[0061]

[0062] Among them, s is the complex frequency variable used to describe the transfer function of the continuous-time system, and τ is the time constant. This parameter is set according to the -3dB cut-off frequency of the first-order low-pass filter, then Therefore:

[0063]

[0064] If the filter is to be implemented, it needs to be discretized. Assuming the sampling time is T, and the bilinear transformation maps the s domain to the z domain, then:

[0065]

[0066] Substituting (11) into (10), then:

[0067]

[0068] where K = ω c , Performing a first-order backward difference on the above equation, then:

[0069]

[0070] where y[n] represents the filtered data at the current nth beat, y[n - 1] represents the filtered data at the (n - 1)th beat, u[n] represents the sampled data before filtering at the nth beat, and u[n - 1] represents the sampled data before filtering at the (n - 1)th beat. Thus, a discrete recursive filtering formula in the time domain is formed, which can perform continuous operations and achieve the filtering and anti-vibration effect. For example Figure 5 , the blue curve represents the sampled data of the IMU heading axis without the vibration reduction method, and the red curve represents the sampled data of the IMU heading axis after adding the vibration reduction method. It can be seen that the vibration reduction method can effectively filter out high-frequency interference vibrations during the dynamic tracking process when adjusting the drilling rig, thereby improving the overall tracking accuracy.

[0071] The preferred embodiments of the present invention have been described in detail above with reference to 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.

[0072] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0073] Furthermore, 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. A small vibration-resistant hole-opening directional measurement device for mining, characterized in that: It includes a battery module arranged in the housing, a measuring module, a vibration reduction module arranged at the bottom of the housing, a display module arranged at the side wall of the housing, a power switch and a charging interface; The measurement module includes a MEMS gyroscope, a MEMS accelerometer, a conductive slip ring, a servo mechanism, an IMU module, a main control board, a motor control board and an external interface connector; the MEMS gyroscope and the MEMS accelerometer are installed on the top of the servo mechanism through the conductive slip ring, the motor control board is installed on the bottom of the servo mechanism, and the main control board and the external interface connector are installed in the measurement module housing; The main control board collects data from the MEMS gyroscope, MEMS accelerometer and IMU module in real time, and performs real-time attitude calculation. The calculation process includes two stages: north-seeking process and tracking process. The battery module is connected to the charging interface, the measuring module and the power switch, and includes a 3S4P lithium iron phosphate battery pack; The vibration reduction module includes a lower screw, an upper nut above the lower screw and a vibration reduction spring therebetween, and also includes a polyurethane support arranged between the lower screw and the upper nut; the polyurethane support has elasticity and damping properties, and can maintain parallelism through the vibration reduction spring, reduce impact energy, and absorb high-frequency vibrations transmitted from the shell base.

2. The small-scale vibration-resistant hole-opening directional measuring device for mining according to claim 1 is characterized in that: The battery module includes a 3S4P lithium iron phosphate battery pack, which contains 12 cylindrical cells. The cells are packaged in three rows in parallel and wrapped with ultra-thin heat shrink film. The capacity is 3.6Ah and the discharge cut-off voltage is ≤8.1V. The battery module is equipped with a battery protection board with short circuit, overcurrent, overcharge and over-discharge protection functions.

3. The small-scale vibration-resistant hole-opening directional measurement device for mining according to claim 2, characterized in that: When the vibration reduction module is installed, a torque wrench tool is used to ensure that the compression value of the vibration reduction spring of each vibration reduction module is equal; the vibration reduction module can absorb the vibration energy of the drilling rig, reduce the bandwidth of the device, and isolate the high-frequency vibration of the drilling rig. At the same time, according to the position of the geometric center of the vibration reduction module, the installation orientation of the MEMS gyroscope and the MEMS accelerometer in the measurement module is optimized, the relative distance is reduced, and the installation flatness and orthogonality of the MEMS gyroscope and the MEMS accelerometer are ensured, which can improve the performance of the MEMS gyroscope in the north-seeking process, reduce the size effect and cone drift error caused by jitter, improve the angular vibration resistance of the measurement module, and improve the north-seeking accuracy.

4. The small-scale vibration-resistant hole-opening directional measurement device for mining according to claim 3 is characterized in that: The measuring module is connected to the display module, and the display module adopts a serial port screen, and the displayed data include azimuth, inclination, tool face angle, temperature, power and stored azimuth data.

5. The measuring method of the small-scale vibration-resistant hole-opening directional measuring device for mining according to claim 4 is characterized in that: During the north-seeking process, the motor control board controls the servo mechanism to drive the MEMS gyroscope and the MEMS accelerometer to rotate evenly at four angles along the horizontal plane. The main control board collects a set of MEMS gyroscope and MEMS accelerometer data every 90°. The four position outputs of the MEMS gyroscope and the MEMS accelerometer are ω1, ω2, ω3, ω4, f1, f2, f3, and f4 respectively: In the above formula, the constant drift of the MEMS gyroscope is ε0, and the constant zero bias of the MEMS accelerometer is The scale factors of MEMS gyroscope and MEMS accelerometer are K g and K a , the angular velocity of the Earth's rotation is ω e , the earth's gravitational acceleration is g, and the azimuth is The inclination angle is θ, the roll angle is γ, and the local latitude is λ; Subtract the output of the MEMS gyro and MEMS accelerometer at position 1 from the output of position 3, and subtract the output of position 2 from the output of position 4 to eliminate the MEMS gyro drift, MEMS accelerometer zero bias and random error, and calculate the azimuth during the north-seeking process. and the inclination angle θ.

6. The measuring method of the small-scale vibration-resistant hole-opening directional measuring device for mining according to claim 5, characterized in that: During the tracking process, the drilling rig adjusts its angle, the hole-opening orientation device rotates the azimuth following the drilling rig guide rail, and the main control board calculates the azimuth based on the north-seeking solution. And the inclination angle θ establishes the initial attitude matrix The IMU module data is collected in real time, and the initial attitude array is updated by measuring the inertial space angular rate. The quaternion strapdown inertial navigation solution principle is used to continuously track and update the real-time azimuth angle. and inclination angle θ1.

7. The measuring method of the small-scale vibration-resistant hole-opening directional measuring device for mining according to claim 5, characterized in that: During the tracking process, the IMU module is directly fixed inside the shell, and tracking anti-vibration is achieved by introducing a low-pass filtering method.

8. The measuring method of the small-scale vibration-resistant hole-opening directional measuring device for mining as claimed in claim 7, characterized in that: During the adjustment process of the drilling rig, the motion bandwidth is in the low frequency band, and a large number of vibration signals are in the high frequency band. Therefore, a low-pass filter is used for digital filtering to filter out high-frequency disturbances and stabilize the system posture.

9. The measuring method of the small-scale vibration-resistant hole-opening directional measuring device for mining as claimed in claim 8, characterized in that: Design a Butterworth low-pass filter, which is a low-pass filter with a maximum flat amplitude response. Therefore, it is flat before the cutoff frequency, ensuring the original value of the signal will not be attenuated due to filtering; the filter cutoff frequency is designed to be ω c , which can effectively attenuate ω c The above vibration frequencies can effectively retain low-frequency motion information. The designed filter is in the form of a first-order inertia link, and its continuous form is expressed as: Where s is a complex frequency variable used to describe the transfer function of a continuous-time system, and τ is a time constant, which is set according to the -3 dB cutoff frequency of a first-order low-pass filter. therefore: To implement the filter, it needs to be discretized. Assuming the sampling time is T, the bilinear change maps the s domain to the z domain, then: Substituting (11) into (10), we get: Where K = ω c , Perform the first-order backward difference on the above formula, then: Among them, y[n] represents the current n-th beat filtered data, y[n-1] represents the n-1th beat filtered data, u[n] represents the n-th beat sampled data before filtering, and u[n-1] represents the n-1th beat sampled data before filtering. From this, a discrete recursive filtering formula in the time domain is formed, and continuous calculations are performed to achieve the filtering and anti-vibration effect.

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