A device and method for accurately measuring the attitude of a drilling rig

Abstract

This invention relates to the field of drilling rig attitude measurement technology, and discloses a device and method for accurately measuring drilling rig attitude. The device for accurately measuring drilling rig attitude includes: calculating initial pitch and initial roll angles; calculating dynamic pitch and dynamic roll angles; calculating the fused azimuth angle; calculating pitch compensation and roll compensation angles; calculating corrected pitch and corrected roll angles; calculating borehole axis tilt and borehole axis azimuth angle; and calculating the direction vector. This invention achieves adaptive fusion of rigid body attitude and dynamic gravity direction by integrating multi-source data such as mast tilt angle, vehicle body tilt angle, triaxial acceleration, triaxial angular velocity, triaxial magnetic field, feed force, and torque. By establishing a structural mechanics model to calculate the bending and torsional deformation of the drill tip, it achieves quantitative compensation for structural elastic deformation, thereby improving the attitude measurement accuracy under near-vertical drilling conditions in alternating soft and hard strata, reducing construction rework, and lowering project costs.

Description

Technical Field

[0001] This invention relates to the field of drilling rig attitude measurement technology, and more specifically, to an apparatus and method for accurately measuring drilling rig attitude. Background Technology

[0002] Rotary drilling rig attitude measurement is a crucial step in pile foundation construction, directly affecting the verticality of the borehole and the bearing capacity of the pile foundation. Currently, commonly used measurement methods mainly include the mast tilt sensor method and the MEMS-IMU (Micro-Electro-Inertial Measurement Unit) fusion measurement method. The mast tilt sensor method acquires the rigid body attitude using dual-axis tilt sensors mounted on the mast and the vehicle body, thereby estimating the drilling direction. It features simple structure and low cost. The MEMS-IMU fusion measurement method combines data from accelerometers, gyroscopes, and magnetometers, and uses filtering algorithms to calculate the tool's attitude, enabling it to adapt to certain dynamic working conditions.

[0003] In near-vertical drilling conditions within alternating layers of soft and hard soil, the measurement accuracy of the above methods will significantly decrease. The actual deviation of the borehole axis is often greater than the deviation shown in the measurement results, leading to the borehole verticality not meeting engineering requirements. This necessitates secondary correction or even rework, increasing construction costs and time. In some deep hole constructions, measurement errors may also cause excessive pile misalignment, affecting the structural safety of the superstructure.

[0004] In summary, existing methods typically treat the mast and drill pipe as ideal rigid bodies, failing to consider the impact of feed force and rotational torque on the elastic deformation of the mast and drill pipe during construction. Furthermore, in near-vertical drilling, the horizontal component of gravity is relatively small, and minute structural deformations are amplified in the attitude measurement results, further exacerbating measurement errors. Moreover, single-sensor or fixed-weight fusion methods struggle to adapt to the dynamic changes in vibration intensity and magnetic interference during drilling, also affecting the stability of the measurement results. Therefore, accurately measuring the true attitude of the drill tip under near-vertical drilling conditions in alternating soft and hard formations has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] This invention provides an apparatus and method for accurately measuring the attitude of a drilling rig, thereby solving the technical problems mentioned in the background section.

[0006] This invention provides a device for accurately measuring the attitude of a drilling rig, comprising: The initial attitude calculation module reads the mast tilt angle and the vehicle tilt angle, and adds them together to obtain the initial pitch angle and the initial roll angle; The dynamic tilt angle calculation module reads the acceleration measurement and lateral angular velocity, obtains the dynamic pitch angle and dynamic roll angle based on the acceleration measurement, and obtains the weighting coefficient based on the acceleration measurement, calibration gravity and lateral angular velocity. The azimuth fusion module reads historical azimuth, vertical angular velocity, magnetic field quantity and time, obtains the integral azimuth based on the historical azimuth, vertical angular velocity and time, obtains the magnetic azimuth based on the magnetic field quantity, dynamic pitch angle and dynamic roll angle, and obtains the fused azimuth based on the integral azimuth, magnetic azimuth and weighting coefficient. The bending and torsion compensation calculation module reads the feed force, torque, eccentricity coefficient, radius, equivalent length, bending stiffness and torsional stiffness. It obtains the two-dimensional bending angle based on the feed force, torque, eccentricity coefficient, radius, equivalent length and bending stiffness, obtains the torsion angle based on the torque, equivalent length and torsional stiffness, and obtains the pitch compensation angle and roll compensation angle based on the two-dimensional bending angle and torsion angle. The tilt angle calculation module obtains the corrected pitch angle based on the initial pitch angle, dynamic pitch angle, weighting coefficient, and pitch compensation angle, and obtains the corrected roll angle based on the initial roll angle, dynamic roll angle, weighting coefficient, and roll compensation angle. The hole shaft attitude calculation module obtains the hole shaft tilt angle and hole shaft azimuth angle based on the corrected pitch angle, corrected roll angle and fused azimuth angle. The direction vector generation module obtains the direction vector based on the hole shaft inclination angle and hole shaft azimuth angle.

[0007] This invention provides a method for accurately measuring the attitude of a drilling rig, comprising the following steps: Step S1: Read the mast tilt angle and the vehicle tilt angle, and add them together to obtain the initial pitch angle and the initial roll angle; Step S2: Read the acceleration measurement and lateral angular velocity, obtain the dynamic pitch angle and dynamic roll angle based on the acceleration measurement, and obtain the weighting coefficient based on the acceleration measurement, calibrated gravity and lateral angular velocity. Step S3: Read the historical azimuth angle, vertical angular velocity, magnetic field quantity and time; obtain the integral azimuth angle based on the historical azimuth angle, vertical angular velocity and time; obtain the magnetic azimuth angle based on the magnetic field quantity, dynamic pitch angle and dynamic roll angle; obtain the fused azimuth angle based on the integral azimuth angle, magnetic azimuth angle and weighting coefficient. Step S4: Read the feed force, torque, eccentricity coefficient, radius, equivalent length, bending stiffness and torsional stiffness. Obtain the two-dimensional bending angle based on the feed force, torque, eccentricity coefficient, radius, equivalent length and bending stiffness. Obtain the torsion angle based on the torque, equivalent length and torsional stiffness. Obtain the pitch compensation angle and roll compensation angle based on the two-dimensional bending angle and torsion angle. Step S5: Obtain the corrected pitch angle based on the initial pitch angle, dynamic pitch angle, weighting coefficient, and pitch compensation angle; obtain the corrected roll angle based on the initial roll angle, dynamic roll angle, weighting coefficient, and roll compensation angle. Step S6: Obtain the hole axis tilt angle and hole axis azimuth angle based on the corrected pitch angle, corrected roll angle, and blended azimuth angle; Step S7: Obtain the direction vector based on the hole shaft inclination angle and hole shaft azimuth angle.

[0008] The beneficial effects of this invention are as follows: By integrating multi-source data such as mast tilt angle, vehicle tilt angle, triaxial acceleration, triaxial angular velocity, triaxial magnetic field, feed force, and torque, this invention achieves adaptive fusion of rigid body attitude and dynamic gravity direction; by establishing a structural mechanics model to calculate the bending and torsional deformation of the drill tip, it achieves quantitative compensation for the elastic deformation of the structure; and by converting the device coordinate system attitude to the local horizontal coordinate system attitude and outputting a three-dimensional unit vector, it achieves a standardized attitude expression usable in construction. This invention can improve the attitude measurement accuracy under near-vertical drilling conditions in alternating soft and hard strata, which helps to improve the verticality of the borehole, reduce construction rework, lower engineering costs, and meet the quality requirements of various pile foundation constructions. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a module of a device for accurately measuring the attitude of a drilling rig according to the present invention; Figure 2 This is a calculation flowchart of a method for accurately measuring the attitude of a drilling rig according to the present invention. Detailed Implementation

[0010] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0011] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of the present invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in one or more embodiments of the present invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" indicate that the element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0012] It should be further explained that alternating layers of soft and hard rock refer to a geological structure in which rock layers of different hardness are alternately distributed in the direction perpendicular to the borehole. The difference in uniaxial compressive strength between adjacent rock layers can typically be several times or even tens of times. Near-vertical drilling refers to a drilling process in pile foundation construction that requires the angle between the borehole axis and the vertical direction to not exceed 3 degrees. This is a common technical requirement for high-rise buildings, bridge pile foundations, and other projects. When performing near-vertical drilling operations in alternating layers of soft and hard rock, the drill bit will generate asymmetrical lateral loads due to the different cutting resistance on both sides as it passes through the interface between the soft and hard rock layers. This load will be transmitted along the drill rod and mast, causing elastic bending deformation of the entire drilling system. At the same time, in order to break the hard rock layers, the drilling rig needs to apply greater feed force and rotation torque, further aggravating the bending and torsional deformation of the drill rod and mast.

[0013] Traditional measurement methods can only acquire rigid body attitude data of the upper part of the mast or the vehicle body, and cannot detect the elastic deformation of the drill tip caused by the load. This results in an inherent deviation between the measured attitude data and the actual attitude of the drill tip. Under near-vertical drilling conditions, the horizontal component of gravitational acceleration is extremely small, and the sensitivity of the tilt sensor to small angle changes is significantly reduced. Even a 0.1-degree elastic deformation of the drill rod can cause the verticality deviation of the hole to exceed one-thousandth. As the drilling depth increases, the effective length of the drill rod continuously increases, and the overall bending stiffness of the system decreases accordingly. The deformation generated under the same load will increase quadratically, causing the actual deviation of the drill axis to accumulate with depth, eventually far exceeding the deviation value displayed by the sensor.

[0014] When the verticality deviation of the borehole exceeds the allowable range, the construction personnel need to stop drilling and adjust the mast posture for secondary correction. Each correction process usually takes tens of minutes, severely impacting construction efficiency. If the requirements are still not met after correction, the drilled section needs to be backfilled and re-drilled, which consumes a large amount of concrete, drill rods, and other construction materials, while increasing labor and equipment rental costs. In deep hole construction exceeding 50 meters in depth, even an initial posture error of 0.2 degrees can result in a horizontal deviation of more than 17 centimeters at the bottom of the hole, causing the pile axis to deviate from the design position. Excessive pile deviation will change the load transfer path of the superstructure, causing the pile foundation to bear additional bending moments and shear forces, reducing the bearing capacity of the pile foundation, and potentially leading to structural cracking, uneven settlement, and other problems during long-term use, threatening the structural safety of the entire project. Therefore, this invention provides a device and method for accurately measuring the posture of the drilling rig.

[0015] like Figures 1-2 As shown, a device for accurately measuring the attitude of a drilling rig includes: The initial attitude calculation module reads the mast tilt angle and the vehicle tilt angle, and adds them together to obtain the initial pitch angle and the initial roll angle; The dynamic tilt angle calculation module reads the acceleration measurement and lateral angular velocity, obtains the dynamic pitch angle and dynamic roll angle based on the acceleration measurement, and obtains the weighting coefficient based on the acceleration measurement, calibration gravity and lateral angular velocity. The azimuth fusion module reads historical azimuth, vertical angular velocity, magnetic field quantity and time, obtains the integral azimuth based on the historical azimuth, vertical angular velocity and time, obtains the magnetic azimuth based on the magnetic field quantity, dynamic pitch angle and dynamic roll angle, and obtains the fused azimuth based on the integral azimuth, magnetic azimuth and weighting coefficient. The bending and torsion compensation calculation module reads the feed force, torque, eccentricity coefficient, radius, equivalent length, bending stiffness and torsional stiffness. It obtains the two-dimensional bending angle based on the feed force, torque, eccentricity coefficient, radius, equivalent length and bending stiffness, obtains the torsion angle based on the torque, equivalent length and torsional stiffness, and obtains the pitch compensation angle and roll compensation angle based on the two-dimensional bending angle and torsion angle. The tilt angle calculation module obtains the corrected pitch angle based on the initial pitch angle, dynamic pitch angle, weighting coefficient, and pitch compensation angle, and obtains the corrected roll angle based on the initial roll angle, dynamic roll angle, weighting coefficient, and roll compensation angle. The hole shaft attitude calculation module obtains the hole shaft tilt angle and hole shaft azimuth angle based on the corrected pitch angle, corrected roll angle and fused azimuth angle. The direction vector generation module obtains the direction vector based on the hole shaft inclination angle and hole shaft azimuth angle.

[0016] In one embodiment of the present invention, the calculation process of the initial attitude calculation module is as follows: The formulas for calculating the initial pitch angle and initial roll angle based on the mast tilt angle and vehicle tilt angle are as follows:

[0017] in, Indicator coordinate system Mast tilt angle along the axial direction Indicator coordinate system Mast tilt angle along the axial direction Represents the local horizontal coordinate system Car body tilt angle in the axial direction, Represents the local horizontal coordinate system Car body tilt angle in the axial direction, Indicates the initial pitch angle. Indicates the initial roll angle.

[0018] It should be noted that the device coordinate system is a local coordinate system established with the drilling rig mast axis as the reference, containing three orthogonal directions: a first horizontal axis, a second horizontal axis, and a vertical axis. The first horizontal axis extends along the left-right direction of the mast, the second horizontal axis extends along the front-back direction of the mast, and the vertical axis extends upward along the mast axis. The local horizontal coordinate system is a local coordinate system established with the horizontal plane of the construction site as the reference, containing three orthogonal directions: a first horizontal axis, a second horizontal axis, and a vertical axis. The first horizontal axis extends eastward, the second horizontal axis extends northward, and the vertical axis extends vertically upward. The mast tilt angle is the angle of inclination of the mast relative to the vertical axis in the device coordinate system's corresponding horizontal axis direction. It can be obtained through a dual-axis mast tilt angle sensor unit with an accuracy of no less than 0.01 degrees. The vehicle body tilt angle is the angle of inclination of the vehicle body relative to the vertical axis in the local horizontal coordinate system's corresponding horizontal axis direction. It can be obtained through a dual-axis vehicle body tilt angle sensor unit with an accuracy of no less than 0.01 degrees. The initial pitch angle is the pitch component of the rigid body attitude obtained by superimposing the tilt angles of the mast and the vehicle body in the first transverse axis direction, and only reflects the overall pitch state of the mast and the vehicle body as rigid bodies. The initial roll angle is the roll component of the rigid body attitude obtained by superimposing the tilt angles of the mast and the vehicle body in the second transverse axis direction, and only reflects the overall roll state of the mast and the vehicle body as rigid bodies.

[0019] Specifically, the mast tilt angle is acquired using a dual-axis tilt sensing unit. This unit typically employs a MEMS (Micro-Electro-Mechanical Systems) dual-axis tilt sensor, which is installed at a height of one-third from the top of the mast. This position is far from the vibration sources of the power head and drill pipe. The mounting surface must be machined to ensure that it is perpendicular to the mast axis. After installation, a high-precision level must be used for calibration to eliminate installation errors.

[0020] Specifically, the vehicle body tilt angle is acquired using a dual-axis tilt angle sensing unit. This unit typically employs a MEMS dual-axis tilt angle sensor, which is mounted on a rigid steel base above the central slewing bearing of the vehicle platform. The base is at least 20 mm thick and has a surface flatness error of no more than 0.02 mm. The sensor is rigidly fixed to the base with bolts, which can isolate the influence of the power head and drill rod vibration on the measurement results.

[0021] Specifically, the device coordinate system and the local horizontal coordinate system have a preset correspondence in the initial alignment state. The vertical axis of the device coordinate system coincides with the initial installation direction of the mast axis. The initial alignment must be completed when the drilling rig is parked on a level surface and the mast is in a vertical position. The alignment process must last for more than 10 seconds to ensure data stability. During drilling, the horizontal rotation relationship of the device coordinate system relative to the local horizontal coordinate system is determined by the fused azimuth angle.

[0022] Furthermore, the present invention relates to the fact that all angle quantities in trigonometric function calculations are used in radians; when the sensor output or display output is in degrees, it is converted to radians before entering the calculation, and then converted from radians to degrees when displayed.

[0023] It should be further explained that the initial attitude reference of the mast body rigid body established in the above embodiment is mainly to provide a unified basic reference value for subsequent dynamic gravity correction and structural deformation compensation. This initial attitude only reflects the overall tilt state of the mast and body as rigid bodies, and does not include the elastic deformation of the drill pipe and mast under construction load. Therefore, it is only used as an intermediate calculation quantity. If it is directly used as the final attitude result, the measurement error caused by structural deformation will be ignored. Through simple tilt angle superposition calculation, the approximate attitude of the rigid body without considering structural deformation can be quickly obtained, providing a stable initial reference for the subsequent multi-source data fusion process, effectively shortening the convergence time of subsequent attitude calculation, and ensuring that usable attitude reference values ​​can be output immediately after the drilling rig starts.

[0024] In one embodiment of the present invention, the calculation process of the dynamic tilt angle calculation module is as follows: Based on the triaxial accelerometer, the formulas for calculating the acceleration modulus and the three normalized quantities are as follows:

[0025] in, Indicator coordinate system Axial acceleration measurement, Indicator coordinate system Axial acceleration measurement, Indicator coordinate system Axial acceleration measurement, Represents the acceleration modulus. Indicator coordinate system Axis normalization measurement Indicator coordinate system Axis normalization measurement Indicator coordinate system Axis normalization quantity; Based on the three normalized values, the formulas for calculating the dynamic pitch angle and dynamic roll angle are as follows:

[0026] in, Indicates the dynamic pitch angle. Indicates the dynamic roll angle. Indicator coordinate system Axis normalization measurement Indicator coordinate system Axis normalization measurement Indicator coordinate system Axis normalization quantity; Based on the acceleration modulus, calibrated gravity, and lateral angular velocity, the formulas for calculating the disturbance coefficient and weighting coefficient are as follows:

[0027] in, This represents the disturbance coefficient. Represents the acceleration modulus. Indicates the calibrated gravity. Indicator coordinate system Lateral angular velocity of the axis, Indicator coordinate system Lateral angular velocity of the axis, Represents the angular velocity constant. This represents the weighting coefficient.

[0028] It should be noted that the triaxial acceleration measure is the output value of the triaxial accelerometer in the three axes of the device's coordinate system, including the gravitational acceleration component and the dynamic acceleration component generated by the drilling rig's motion. This value can be obtained through triaxial accelerometer acquisition at a frequency of no less than 100Hz. The acceleration modulus is the square root of the sum of the squares of the triaxial acceleration measures, reflecting the magnitude of the acceleration vector. The normalized value is a dimensionless value obtained by dividing each axis acceleration measure by the acceleration modulus and then inverting it. It eliminates the influence of acceleration magnitude, retaining only the direction information of acceleration. The dynamic pitch angle is the pitch angle calculated from the normalized acceleration direction. Under static conditions, it is consistent with the true pitch angle, but under dynamic conditions, it is affected by vibration and may deviate. The dynamic roll angle is the roll angle calculated from the normalized acceleration direction. Under static conditions, it is consistent with the true roll angle, but under dynamic conditions, it is affected by vibration and may deviate.

[0029] It should be noted that the calibration gravity is a locally calibrated gravitational acceleration value, which can be determined through on-site static calibration or by using local standard gravity values. Calibration gravity varies slightly between different regions. The lateral angular velocity is the output value of the three-axis gyroscope in the two horizontal axes of the device's coordinate system, reflecting the rotational speed and vibration intensity of the drilling rig around these axes. It can be obtained through the three-axis gyroscope, with the acquisition frequency consistent with that of the three-axis accelerometer. The angular velocity constant is a preset angular velocity normalization constant, a user-defined parameter used to convert the lateral angular velocity into a dimensionless ratio. The disturbance coefficient is a dimensionless coefficient characterizing the degree of dynamic contamination of the acceleration measurement results; a larger value indicates stronger dynamic interference. The weighting coefficient is a dimensionless coefficient used to adjust the proportion of acceleration attitude in the fusion calculation; a larger value indicates higher reliability of the acceleration tilt angle.

[0030] Specifically, the triaxial acceleration measurement is acquired using a triaxial accelerometer, which is typically integrated with a triaxial gyroscope in the same MEMS inertial measurement unit. The unit is installed near the connection between the power head and the mast, a location that accurately reflects the drill pipe's motion state with relatively moderate vibration intensity. The mounting surface of the inertial measurement unit needs to be machined to ensure parallelism with the device's coordinate system reference plane. After installation, tilt calibration is required, with an installation error not exceeding 0.05 degrees.

[0031] Specifically, the lateral angular velocity is acquired using a triaxial gyroscope. This sensor shares the same mounting base as the triaxial accelerometer and can synchronously output real-time angular velocity data in three axes, with a data synchronization error of no more than 1 millisecond. The preferred range for the angular velocity constant is 10 rad / s to 50 rad / s, with the specific value determined based on the statistical range of the lateral angular velocity data acquired by the drilling rig. Under normal construction conditions, the preferred value is 20 rad / s.

[0032] The angular velocity constant is used to synthesize the angular velocities in the two transverse axes of the device coordinate system into a dimensionless angular velocity ratio. The angular velocity constant is determined based on the statistical range of the drilling rig's transverse angular velocity data. Specifically, under the same type of drilling rig, the same type of drill rod, and the same or similar construction conditions, the angular velocities in the first and second transverse axes of the device coordinate system are pre-collected. At each sampling moment, the square root of the sum of the squares of the two transverse angular velocities is taken to obtain the transverse angular velocity modulus. After removing instantaneous spikes or obviously abnormal impact data from the sensor, an effective sample sequence of transverse angular velocity modulus is obtained. The 95th percentile value of this effective sample sequence is selected as the candidate angular velocity constant.

[0033] When the candidate angular velocity constant is less than 10 rad / s, the angular velocity constant is taken as 10 rad / s; when the candidate angular velocity constant is greater than 50 rad / s, the angular velocity constant is taken as 50 rad / s; when the candidate angular velocity constant is between 10 rad / s and 50 rad / s, the candidate angular velocity constant is taken. Under normal construction conditions, when the 95th percentile of the lateral angular velocity modulus is close to 20 rad / s, the angular velocity constant is preferably taken as 20 rad / s.

[0034] In this way, when the lateral angular velocity is close to the level of strong disturbance under the working condition, the angular velocity ratio is close to 1; when the lateral angular velocity is lower than the level, the angular velocity ratio is small; when the lateral angular velocity is higher than the level, the angular velocity ratio increases, so that the disturbance coefficient and weighting coefficient can adapt to the vibration intensity.

[0035] Specifically, the calibration gravity is the average value of the triaxial acceleration modulus at each sampling time under static conditions. During the calculation, the square and square root of the triaxial acceleration at each sampling time are first calculated to obtain the acceleration modulus sequence. Then, the maximum and minimum values ​​in the acceleration modulus sequence are removed, and the average value of the remaining acceleration modulus is calculated to obtain the calibration gravity.

[0036] In addition, the calculation rule of the bivariate arctangent function is that the input is two orthogonal components and the output is the corresponding angle value. The output angle range covers from -180 degrees to +180 degrees, which can correctly reflect the angle information of the four quadrants and avoid the problems of angle jump or quadrant judgment error.

[0037] It should be further explained that the above embodiments can quantify the influence of dynamic disturbances on gravity direction measurement by measuring the degree of deviation of the acceleration modulus from the calibrated gravity and the magnitude of the lateral angular velocity. This allows for dynamic adjustment of the weight of the acceleration tilt angle in subsequent fusion calculations. Traditional fixed-weight fusion methods are difficult to adapt to the drastic changes in vibration intensity during drilling operations. Strong vibration conditions can lead to distortion in gravity direction measurement. This invention can increase the weight of the acceleration tilt angle when vibration is low and decrease the weight when vibration is high, ensuring the stability of attitude estimation. It can adaptively suppress the interference of drilling rig vibration and dynamic acceleration on gravity direction measurement. Even under dynamic conditions such as drilling rig rotation, feeding, and impact, it can still reduce the impact of dynamic interference on tilt angle estimation and avoid attitude abrupt changes caused by dynamic interference.

[0038] In one embodiment of the present invention, the calculation process of the azimuth fusion module is as follows: Based on the historical azimuth angle, vertical angular velocity, and sampling time, the formula for calculating the integral azimuth angle is as follows:

[0039] in, Indicates historical azimuth. Indicator coordinate system Vertical angular velocity of the axis, Indicates the sampling time. Indicates the integral azimuth angle; Based on the triaxial magnetic field quantity, dynamic pitch angle, and dynamic roll angle, the formulas for calculating the horizontal magnetic field quantity and magnetic azimuth angle are as follows:

[0040]

[0041] in, Represents the local horizontal coordinate system Horizontal magnetic field quantity of the axis Indicator coordinate system Axial magnetic field quantity, Indicates the dynamic pitch angle. Indicator coordinate system Axial magnetic field quantity, Indicates the dynamic roll angle. Indicator coordinate system Axial magnetic field quantity, Represents the local horizontal coordinate system Horizontal magnetic field quantity of the axis Indicates the magnetic azimuth angle; The formula for calculating the fused azimuth angle, based on the integral azimuth angle, magnetic azimuth angle, and weighting coefficient, is as follows:

[0042] in, Indicates the fused azimuth angle. Indicates the weighting coefficient. Indicates the magnetic azimuth angle. This represents the integral azimuth angle.

[0043] It should be noted that the historical azimuth angle is the fused azimuth angle of the previous sampling period, used as the initial value for the gyro integral in the current period. The vertical angular velocity is the output value of the three-axis gyroscope along the vertical axis of the device coordinate system, reflecting the rotational speed of the drilling rig around the vertical axis. It can be obtained by acquiring data through the three-axis gyroscope, with the acquisition frequency consistent with that of the three-axis accelerometer. The sampling time is the system's preset sampling period, a user-defined parameter that determines the system's data update frequency and response speed. The integrated azimuth angle is a short-time continuous azimuth estimate obtained by integrating the vertical angular velocity. It has high accuracy in the short term but accumulates drift error over time.

[0044] It should be noted that the triaxial magnetic field quantity is the output value of the triaxial magnetometer in the three axes of the device's coordinate system, reflecting the components of the Earth's magnetic field in the three axes. This value can be obtained through a triaxial magnetometer with a sampling frequency of at least 50Hz. The horizontal magnetic field quantity consists of two orthogonal components of the magnetic field in the local horizontal plane after tilt compensation, eliminating the influence of attitude tilt on magnetic azimuth calculation. The magnetic azimuth angle is calculated from the horizontal magnetic field components, exhibiting good long-term stability but being susceptible to magnetic interference from surrounding metal structures and electrical equipment. The azimuth sine is a weighted sum of the sine of the magnetic azimuth angle and the integral azimuth angle sine, used for vector synthesis to fuse the azimuth angle. The azimuth cosine is a weighted sum of the cosine of the magnetic azimuth angle and the integral azimuth angle cosine, also used for vector synthesis to fuse the azimuth angle. The fused azimuth angle is the final azimuth angle calculated from the azimuth sine and azimuth cosine, balancing the long-term stability of magnetic azimuth and the short-term accuracy of gyroscopic azimuth.

[0045] Specifically, the triaxial accelerometer, triaxial gyroscope, and triaxial magnetometer are integrated into the same attitude measurement unit, sharing the same coordinate system. After installation, the triaxial magnetometer requires on-site magnetic calibration. The calibration method involves parking the drilling rig in an open area free from strong magnetic interference, slowly rotating the mast one revolution, and collecting magnetic field data under different attitudes. An ellipsoidal fitting algorithm is then used to calculate the magnetometer's zero bias and proportional coefficient, eliminating the influence of installation errors and surrounding magnetic interference. Vertical angular velocity is acquired using a triaxial gyroscope, which is integrated with the triaxial accelerometer and magnetometer into the same attitude measurement unit. This gyroscope can synchronously output angular velocity data in three axes with a synchronization error of no more than 1 millisecond.

[0046] Specifically, the preferred sampling time range is 10ms to 100ms. The specific value is determined based on the dynamic response requirements of the drilling rig and the computing power of the controller. A sampling time that is too short will increase the controller's computational burden, while a time that is too long will cause system response lag. Under normal construction conditions, the preferred value is 50ms. The reference definition for magnetic azimuth and fused azimuth is based on north, with east as positive, and the angle range covers -180 degrees to +180 degrees. This is consistent with the azimuth definition commonly used in engineering surveying, making it easier for construction personnel to understand and use.

[0047] Furthermore, the purpose of using sine and cosine vector synthesis is to avoid angle jumps around ±180 degrees. When the azimuth changes from 179 degrees to -179 degrees, direct angle averaging will result in an incorrect 0-degree result, while vector synthesis can output a continuous 180-degree result, ensuring the continuity of the azimuth.

[0048] It should be further explained that the above embodiments use the same dynamic weighting system to couple the magnetic azimuth and gyro integral azimuth. This can simultaneously utilize the characteristics of magnetic azimuth without long-term drift and gyro azimuth against dynamic interference. If different weighting systems are used to adjust the magnetic azimuth and gyro azimuth separately, the physical meaning of the fusion result will be unclear, and azimuth jumps caused by weight abrupt changes are likely to occur. The same weighting system can ensure the continuity and consistency of the fusion result. It can effectively solve the problems of single magnetic azimuth being susceptible to magnetic interference and single gyro azimuth being prone to accumulated drift. Even under the conditions of local magnetic interference and dynamic movement of the drilling rig, it can still maintain the stability and accuracy of azimuth angle measurement and avoid abrupt changes or long-term drift in azimuth angle.

[0049] In one embodiment of the present invention, the calculation process of the bending and torsional compensation calculation module is as follows: Based on the feed force, torque, eccentricity coefficient, and radius, the formulas for calculating the feed side force and torque side force are as follows:

[0050] in, Indicates the feed side force. Indicates the eccentricity coefficient. Indicates supply force. Indicates torque lateral force. Indicates torque, Indicates radius; The formulas for calculating the two-dimensional bending angle and torsion angle are as follows, based on the feed side force, torque side force, torque, equivalent length, elastic modulus, moment of inertia of section, shear modulus, and polar moment of inertia:

[0051] in, Indicator coordinate system First bending angle in the axial direction, Indicates the feed side force. Indicates the equivalent length. Indicates the elastic modulus. Indicator coordinate system Moment of inertia of the cross section in the axial direction Indicator coordinate system Second bending angle in the axial direction, Indicates torque lateral force. Indicator coordinate system Moment of inertia of the cross section in the axial direction Indicates the angle of twist. Indicates torque, Indicates shear modulus, Indicator coordinate system Polar moment of inertia in the axial direction; Based on the two-dimensional bending angle and twist angle, the formulas for calculating the pitch compensation angle and roll compensation angle are as follows:

[0052] in, Indicates the pitch compensation angle. Indicates the first bending angle. Indicates the angle of twist. Indicates the second bending angle. This indicates the roll compensation angle.

[0053] It should be noted that feed force is the propulsive force applied to the drill bit along the drill rod axis by the drilling rig, used to break up formation rocks. It can be obtained through a feed force measurement unit with a sampling frequency of not less than 50Hz. Torque is the torsional moment applied by the power head along the drill rod axis, used to drive the drill bit to rotate and cut the formation. It can be obtained through a slewing torque measurement unit with a sampling frequency of not less than 50Hz. Eccentricity coefficient is the eccentric force coefficient of the formation drill bit, determined on-site by the drill bit structure, formation hardness difference, and uneven stress distribution on the tooth profile. It is a calibration parameter, and the eccentricity coefficient varies for different drill bits and formations. Radius is the effective radius of the drill bit, i.e., the equivalent radius of action used when the torque is converted into tangential force. It is a preset parameter and equal to the average distance from the outermost end of the drill bit cutting teeth to the drill rod axis. Equivalent length is the equivalent length of the mast, power head, and upper drill rod involved in bending and torsional deformation. It is a preset parameter and reflects the overall bending and torsional stiffness of the system. The elastic modulus is a parameter that characterizes a material's ability to resist tensile and compressive elastic deformation. It can be obtained by looking up material parameters. The elastic modulus of steel is usually a fixed value.

[0054] It should be noted that the first section moment of inertia is a parameter characterizing the section's resistance to bending in the first orthogonal bending direction. It can be obtained through structural dimension calculations and is closely related to the shape and size of the section. The second section moment of inertia is a parameter characterizing the section's resistance to bending in the second orthogonal bending direction. It can be obtained through structural dimension calculations and is closely related to the shape and size of the section. Shear modulus is a parameter characterizing the material's resistance to shear and torsional deformation. It can be obtained through material parameter lookup; the shear modulus of steel is usually a fixed value. Polar moment of inertia is a parameter characterizing the section's resistance to torsion about its axis. It can be obtained through structural dimension calculations and is closely related to the shape and size of the section. Feed side force is the equivalent lateral force derived from the feed force and is one of the main causes of drill pipe bending. Torque side force is the equivalent tangential lateral force derived from the torque and is orthogonal to the direction of the feed side force.

[0055] It should be noted that the first bending angle is the drill tip bending angle in the first orthogonal direction, determined by the feed lateral force and the system's bending stiffness. The second bending angle is the drill tip bending angle in the second orthogonal direction, determined by the torque lateral force and the system's bending stiffness. The torsion angle is the drill pipe torsional phase angle caused by the torque along the equivalent length, determined by the torque and the system's torsional stiffness. The pitch compensation angle is the drill tip pitch attitude angle deviation after torsional phase rotation, used to correct the initial pitch angle. The roll compensation angle is the drill tip roll attitude angle deviation after torsional phase rotation, used to correct the initial roll angle.

[0056] Specifically, the feed force is acquired using a feed force measurement unit. This unit typically installs high-precision pressure sensors in both the rodless and rod chambers of the mast feed cylinder. The axial feed force is calculated by measuring the pressure difference between the two chambers. The calculation must consider the difference between the piston area and the piston rod area, and the measurement accuracy must be no less than 1%. When calculating the feed force using cylinder pressure, the feed force is the product of the rodless chamber pressure and the effective area of ​​the rodless chamber, minus the product of the rod chamber pressure and the effective area of ​​the rod chamber. The feed direction is positive when it points from the drill pipe axis towards the drill bit.

[0057] Specifically, the torque is acquired by a rotary torque measurement unit, which typically consists of a Wheatstone bridge composed of resistance strain gauges attached to the output shaft of the power head. When the output shaft is subjected to torque, the strain gauges deform, causing a change in resistance. The bridge outputs a voltage signal proportional to the torque, which is amplified and filtered to obtain the torque value. The measurement accuracy is no less than 2%.

[0058] Specifically, the eccentricity coefficient is determined through field drilling tests in different formations, fitting the correspondence between feed force and lateral sway. Calibration requires drilling in a uniform, alternating layer of soft and hard formations with known geological conditions, using the same type of drill bit and drill rod, and conducting tests with three different feed forces. After drilling, the actual borehole inclination data is measured using a fiber optic inclinometer. When calibrating the eccentricity coefficient, the drill bit type, drill rod type, radius, equivalent length, elastic modulus, section moment of inertia, shear modulus, and polar moment of inertia are kept constant. The borehole axis inclination and azimuth angles under different feed forces are collected. Based on the initial pitch angle, dynamic pitch angle, initial roll angle, dynamic roll angle, weighting coefficient, torque lateral force, and torsional angle, the attitude angle component caused by non-feed force is subtracted to obtain the first bending angle caused by the feed force. Then, based on the linear relationship between the first bending angle and the feed force, the eccentricity coefficient value is obtained through back-calculation or linear regression. This calibration is repeated three times, and the average value is taken.

[0059] The field calibration of the eccentricity coefficient includes the following steps: Under the condition that the drill bit type, drill pipe type, effective drill bit radius, equivalent length, elastic modulus, moment of inertia of the first section, moment of inertia of the second section, shear modulus and polar moment of inertia remain unchanged, select a test section with known formation conditions, conduct drilling tests with at least three different feed forces, and record the feed force, torque, initial pitch angle, initial roll angle, dynamic pitch angle, dynamic roll angle, weighting coefficient, fusion azimuth angle and equivalent length corresponding to each test.

[0060] After drilling is completed, the actual hole axis inclination angle and actual hole axis azimuth angle of the test hole section are measured by fiber optic inclinometer. Then, following the reverse process of the hole axis attitude calculation module of this application, the actual hole axis inclination angle and actual hole axis azimuth angle are converted into two horizontal slope components in the local horizontal coordinate system. Based on the fused azimuth angle, the actual hole axis inclination angle and actual hole axis azimuth angle are converted back to the device coordinate system to obtain the measured pitch equivalent angle and measured roll equivalent angle.

[0061] The measured pitch compensation is obtained by subtracting the rigid body pitch angle obtained by fusing the initial pitch angle and the dynamic pitch angle according to the weighting coefficient from the measured pitch equivalent angle; the measured roll compensation is obtained by subtracting the rigid body roll angle obtained by fusing the initial roll angle and the dynamic roll angle according to the weighting coefficient from the measured roll equivalent angle.

[0062] Based on the torque, effective drill bit radius, equivalent length, elastic modulus, first section moment of inertia, shear modulus, and polar moment of inertia, and following the bending-torsion compensation calculation process disclosed in this application, the torque side force, second bending angle, and torsion angle are obtained. Then, the measured pitch compensation, measured roll compensation, second bending angle, and torsion angle are substituted into the correspondence between the pitch compensation angle and roll compensation angle disclosed in this application to obtain the first bending angle caused by the feed force. This solution process is equivalent to rotating the measured pitch compensation and measured roll compensation in the opposite direction according to the torsion angle and taking the component in the feed bending direction.

[0063] Since there is a linear relationship between the first bending angle and the product of "feed force multiplied by the square of the equivalent length and then divided by twice the elastic modulus and the moment of inertia of the second section", the proportionality coefficient of this linear relationship is the eccentricity coefficient. Therefore, the eccentricity coefficient can be calculated separately for each set of tests and the average value can be taken. Alternatively, a linear regression can be performed with the aforementioned feed force-related quantity as the independent variable and the first bending angle as the dependent variable, and the regression slope can be used as the eccentricity coefficient. The average value of multiple calibration results is taken as the final eccentricity coefficient under the current drill bit, drill pipe, and formation conditions.

[0064] Specifically, the equivalent length is determined by simulating the bending and torsional deformation of the mast drill pipe system through structural mechanics simulation, combined with on-site calibration correction. During the simulation, finite element software is used to create a three-dimensional solid model of the mast, power head, and upper drill pipe. Different axial forces and torques are applied to calculate the deformation at the drill tip. The system is simplified into a cantilever beam model. The length of the cantilever beam is adjusted to make the deformation consistent with the simulation results. Then, it is corrected by using on-site multi-point inclination angle measurement data of the drill pipe.

[0065] Specifically, the equivalent bending stiffness and equivalent torsional stiffness are determined based on the elastic measurement chain formed by the mast, power head, and upper drill pipe. When using the finite element method for calibration, unit lateral force and unit torque are applied at different drill pipe extension lengths, and the drill tip angular displacement is calculated. The equivalent bending stiffness is determined based on the correspondence between lateral force and angular displacement, and the equivalent torsional stiffness is determined based on the correspondence between torque and torsion angle. A correspondence table between drill pipe extension length and equivalent length, equivalent bending stiffness, and equivalent torsional stiffness is established. The equivalent length needs to be adjusted according to the actual extension length of the drill pipe. Before construction, a correspondence table between the equivalent length and the drill pipe extension length needs to be established. During drilling, the drill pipe extension length is read in real time, and the equivalent length value under the current working condition is obtained by referring to the table.

[0066] Specifically, the elastic modulus, moment of inertia, shear modulus, and polar moment of inertia are obtained by calculation based on material parameters and structural dimensions. The elastic modulus and shear modulus are obtained by consulting national standards based on the steel grades of the mast and drill pipe, while the moment of inertia and polar moment of inertia are calculated using standard formulas in structural mechanics based on the actual dimensions of the box-shaped section of the mast and the circular hollow section of the drill pipe.

[0067] Furthermore, the moment of inertia of the first section corresponds to the moment of inertia of the section in the first horizontal axis direction of the device coordinate system, and the moment of inertia of the second section corresponds to the moment of inertia of the section in the second horizontal axis direction of the device coordinate system; the denominator of the first bending angle adopts the moment of inertia of the second section orthogonal to the first bending direction, and the denominator of the second bending angle adopts the moment of inertia of the first section orthogonal to the second bending direction.

[0068] It should be further explained that the above embodiments convert the feed force and torque during construction into sources of attitude measurement error. The amount of elliptical sway at the drill tip is calculated through a structural mechanics model. Traditional rigid body attitude measurement methods assume that the mast and drill pipe are ideal rigid bodies and ignore the elastic deformation under construction loads. In reality, due to the different bending stiffness of the system in two orthogonal directions and the rotation of the bending direction by torsion, the sway trajectory of the drill tip is elliptical. This invention can quantitatively calculate and compensate for this sway, making up for the shortcomings of traditional methods. It can effectively measure the structural deformation deviation of the drill tip caused by load and torque, making the attitude measurement results closer to the actual borehole axis direction. Its advantages are particularly obvious in deep hole drilling and construction in soft and hard interbedded strata.

[0069] In one embodiment of the present invention, the calculation process of the tilt angle correction calculation module is as follows: The formulas for calculating the corrected pitch angle and corrected roll angle are as follows, based on the initial pitch angle, dynamic pitch angle, weighting factor, pitch compensation angle, initial roll angle, dynamic roll angle, and roll compensation angle:

[0070] in, Indicates correction of pitch angle, Indicates the weighting coefficient. Indicates the dynamic pitch angle. Indicates the initial pitch angle. Indicates the pitch compensation angle. Indicates correction of roll angle, Indicates the dynamic roll angle. Indicates the initial roll angle. This indicates the roll compensation angle.

[0071] It should be noted that the corrected pitch angle is the drill tip pitch angle obtained by integrating the initial pitch angle, dynamic pitch angle, and pitch compensation angle, reflecting the true pitch state of the drill tip in the device coordinate system. The corrected roll angle is the drill tip roll angle obtained by integrating the initial roll angle, dynamic roll angle, and roll compensation angle, reflecting the true roll state of the drill tip in the device coordinate system.

[0072] Specifically, the weighting coefficient ranges from 0 to 1. The larger the value, the higher the reliability of the acceleration tilt angle. When the disturbance coefficient increases, the weighting coefficient approaches 0, and the proportion of dynamic pitch angle and dynamic roll angle in the fusion decreases. When the weighting coefficient is 1, dynamic pitch angle and dynamic roll angle are used as rigid body attitude references, which are suitable for static or weak vibration conditions.

[0073] Specifically, the superposition logic of the three components is that the weighted sum of the dynamic pitch angle and the initial pitch angle reflects the rigid body attitude obtained by sensor fusion. After superimposing the pitch compensation angle, the true attitude of the drill tip considering structural deformation is obtained. The superposition logic in the roll direction is completely consistent with that in the pitch direction. This superposition method has clear physical meaning, low computational load, and can meet real-time requirements.

[0074] It should be noted that the above embodiments combine the dynamic attitude obtained by multi-sensor fusion with the deformation compensation calculated by structural mechanics, which can achieve a unified solution for rigid body attitude and elastic deformation attitude. Multi-sensor fusion can only obtain the rigid body attitude at the sensor installation position, which is difficult to reflect the elastic deformation of the drill tip. Structural mechanics compensation can calculate the deformation deviation of the drill tip relative to the sensor position. Only by combining the two can the true attitude of the drill tip be obtained. This can avoid misjudging the true drill tip sway as sensor noise under high load and strong torque conditions, improve the attitude measurement accuracy under extreme construction conditions, and ensure that the hole verticality meets the engineering requirements.

[0075] In one embodiment of the present invention, the calculation process of the hole shaft attitude calculation module is as follows: Based on the corrected pitch angle, corrected roll angle, and blended azimuth angle, the formulas for calculating the first slope and the second slope are as follows:

[0076]

[0077] in, Represents the local horizontal coordinate system The first slope of the axis, Indicates correction of pitch angle, Indicates the fused azimuth angle. Indicates correction of roll angle, Represents the local horizontal coordinate system The second slope of the axis; Based on the first slope and the second slope, the formulas for calculating the hole shaft inclination angle and hole shaft azimuth angle are as follows:

[0078] in, Indicates the inclination angle of the hole shaft. Indicates the first slope quantity. This indicates the second slope quantity. Indicates the azimuth angle of the hole shaft.

[0079] It should be noted that the first slope is the slope component of the borehole axis along the first horizontal axis of the local horizontal coordinate system, which is equal to the ratio of the projected length of the borehole axis along the first horizontal axis to its vertical length. The second slope is the slope component of the borehole axis along the second horizontal axis of the local horizontal coordinate system, which is equal to the ratio of the projected length of the borehole axis along the second horizontal axis to its vertical length. The borehole axis inclination angle is the angle by which the borehole axis deviates from the vertical direction, reflecting the overall inclination of the borehole. The borehole axis azimuth angle is the azimuth angle of the horizontal projection of the borehole axis, reflecting the horizontal orientation of the borehole.

[0080] Specifically, the first horizontal axis of the local horizontal coordinate system corresponds to the east direction, and the second horizontal axis corresponds to the north direction. This coordinate system is consistent with the engineering survey coordinate system commonly used on construction sites, which facilitates the integration of data with surveying equipment such as total stations and GPS (Global Positioning System).

[0081] Specifically, the reference for the aperture axis azimuth angle is the same as the fused azimuth angle, both based on the north direction with east as positive, and the angle range covers from -180 degrees to +180 degrees. When the aperture axis tilt angle is 0, the aperture axis is in a vertical state, and the azimuth angle has no practical meaning. At this time, the azimuth angle of the previous effective sampling period is output.

[0082] Furthermore, the geometric relationship between the slope and the hole shaft inclination angle is that the square root of the sum of the squares of the two slopes is the tangent of the hole shaft inclination angle. In display verification or quick estimation, when the hole shaft inclination angle is less than 1 degree, the slope magnitude can be used to approximate the radian value of the hole shaft inclination angle; the final output is still obtained according to the hole shaft inclination angle calculation formula.

[0083] It should be further explained that the above embodiment converts the drill tip attitude in the device coordinate system into the hole shaft attitude in the local horizontal coordinate system. The device coordinate system is a local coordinate system that moves with the drilling rig. The coordinate systems of the drilling rig device are different at different locations, making it difficult to directly compare the attitudes of different boreholes. The local horizontal coordinate system is a global coordinate system fixed at the construction site. The converted result can be directly used for construction records and engineering evaluation. It can output local coordinate attitude results that can be used for construction, and can be directly used for engineering applications such as hole shaft recording, verticality evaluation, and spatial positioning, without requiring construction personnel to perform additional coordinate transformation.

[0084] In one embodiment of the present invention, the calculation process of the direction vector generation module is as follows: The formula for calculating the direction vector based on the borehole shaft inclination angle and borehole shaft azimuth angle is as follows:

[0085] in, This represents the eastward component of the direction vector. Indicates the inclination angle of the hole shaft. Indicates the azimuth angle of the hole shaft. This represents the north component of the direction vector. This represents the upward component of the direction vector.

[0086] It should be noted that the direction vector is a unit vector representing the three-dimensional direction of the borehole axis, with a magnitude of 1, uniquely representing a direction in three-dimensional space. The eastward component is the component of the unit vector on the eastward axis of the local northeast coordinate system, reflecting the proportion of the borehole axis projected eastward. The northward component is the component of the unit vector on the northward axis of the local northeast coordinate system, reflecting the proportion of the borehole axis projected northward. The upward component is the component of the unit vector on the upward axis of the local northeast coordinate system, reflecting the proportion of the borehole axis projected upward.

[0087] Specifically, the local northeast coordinate system is defined as having east and north as horizontally orthogonal directions and an upward direction as vertically upward. This coordinate system is a right-handed coordinate system, consistent with the coordinate system definition commonly used in global navigation satellite systems, which facilitates integration with satellite positioning data.

[0088] Specifically, the characteristic of a unit vector is that the sum of the squares of its three components equals 1, uniquely representing a direction in three-dimensional space, and avoiding the multi-valued problem found in angle representations. The direction vector is used to represent the direction of the borehole axis, with its positive direction defined as from the bottom of the borehole to the borehole opening; when the drilling direction needs to be represented, the direction vector is reversed. Furthermore, the geometric correspondence between the direction vector and the borehole axis inclination and azimuth is as follows: the east and north components are obtained by multiplying the sine of the borehole axis inclination and the sine and cosine of the azimuth, while the upward component is the cosine of the borehole axis inclination. This transformation is reversible, and the borehole axis inclination and azimuth can be calculated from the direction vector.

[0089] It should be further explained that the above embodiments convert the attitude results in angular form into three-dimensional unit vectors, which can achieve a standardized three-dimensional expression of the borehole axis direction. The angular form results require multiple trigonometric function conversions during three-dimensional calculations, which can easily introduce calculation errors. Moreover, different angle definition orders will lead to different conversion results. The unit vector is a direct three-dimensional direction representation, which is simple to calculate and less prone to errors. The output unit vector can be directly connected to the three-dimensional coordinate calculation system, avoiding sign errors or inconsistencies in coordinate references introduced by angle convention conversions, and facilitating data interaction with BIM (Building Information Modeling) systems, three-dimensional geological modeling software, etc.

[0090] In one embodiment of the present invention, such as Figure 2 As shown, a method for accurately measuring the attitude of a drilling rig includes the following steps: Step S1: Read the mast tilt angle and the vehicle tilt angle, and add them together to obtain the initial pitch angle and the initial roll angle; Step S2: Read the acceleration measurement and lateral angular velocity, obtain the dynamic pitch angle and dynamic roll angle based on the acceleration measurement, and obtain the weighting coefficient based on the acceleration measurement, calibrated gravity and lateral angular velocity. Step S3: Read the historical azimuth angle, vertical angular velocity, magnetic field quantity and time; obtain the integral azimuth angle based on the historical azimuth angle, vertical angular velocity and time; obtain the magnetic azimuth angle based on the magnetic field quantity, dynamic pitch angle and dynamic roll angle; obtain the fused azimuth angle based on the integral azimuth angle, magnetic azimuth angle and weighting coefficient. Step S4: Read the feed force, torque, eccentricity coefficient, radius, equivalent length, bending stiffness and torsional stiffness. Obtain the two-dimensional bending angle based on the feed force, torque, eccentricity coefficient, radius, equivalent length and bending stiffness. Obtain the torsion angle based on the torque, equivalent length and torsional stiffness. Obtain the pitch compensation angle and roll compensation angle based on the two-dimensional bending angle and torsion angle. Step S5: Obtain the corrected pitch angle based on the initial pitch angle, dynamic pitch angle, weighting coefficient, and pitch compensation angle; obtain the corrected roll angle based on the initial roll angle, dynamic roll angle, weighting coefficient, and roll compensation angle. Step S6: Obtain the hole axis tilt angle and hole axis azimuth angle based on the corrected pitch angle, corrected roll angle, and blended azimuth angle; Step S7: Obtain the direction vector based on the hole shaft inclination angle and hole shaft azimuth angle.

[0091] It should be noted that this device can be directly integrated into the control system of existing rotary drilling rigs. The hardware components include a mast dual-axis tilt sensor unit, a vehicle body dual-axis tilt sensor unit, a MEMS inertial measurement unit, a triaxial magnetometer, a feed force measurement unit, a slewing torque measurement unit, and an embedded controller. During installation, the sensors should be fixed and calibrated according to the aforementioned installation requirements. Before construction, system parameter calibration should be completed, including calibration of gravity, eccentricity coefficient, equivalent length correspondence table, equivalent bending stiffness correspondence table, and equivalent torsional stiffness correspondence table. During drilling, the controller synchronously collects data from all sensors at a sampling period of 50ms, calculates the drill tip attitude according to preset steps, and transmits the calculation results to the cab display unit in real time.

[0092] The system ultimately outputs the actual borehole inclination angle, borehole azimuth angle, and three-dimensional unit direction vector. For example, in the construction of a soft-hard interbedded strata, when the drill pipe extension length is 20 meters, the feed force is 200 kN, and the torque is 50 kN×m, the system outputs a borehole inclination angle of 0.3 degrees, a borehole azimuth angle of 45 degrees, and a three-dimensional unit direction vector with an eastward component of 0.0037, a northward component of 0.0037, and an upward component of 0.999986. Construction personnel can view the attitude data in real time through the display unit. When the borehole inclination angle exceeds the preset threshold of 0.5 degrees, the system can issue an early warning prompt, guiding the operator to adjust the mast attitude to ensure that the verticality of the borehole meets the engineering requirements.

[0093] The content of this embodiment has been described above, but this embodiment is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this embodiment, all of which are within the protection scope of this embodiment.

Claims

1. A device for accurately measuring the attitude of a drilling rig, characterized in that, include: The initial attitude calculation module reads the mast tilt angle and the vehicle tilt angle, and adds them together to obtain the initial pitch angle and the initial roll angle; The dynamic tilt angle calculation module reads the acceleration measurement and lateral angular velocity, obtains the dynamic pitch angle and dynamic roll angle based on the acceleration measurement, and obtains the weighting coefficient based on the acceleration measurement, calibration gravity and lateral angular velocity. The azimuth fusion module reads historical azimuth, vertical angular velocity, magnetic field quantity and time, obtains the integral azimuth based on the historical azimuth, vertical angular velocity and time, obtains the magnetic azimuth based on the magnetic field quantity, dynamic pitch angle and dynamic roll angle, and obtains the fused azimuth based on the integral azimuth, magnetic azimuth and weighting coefficient. The bending and torsion compensation calculation module reads the feed force, torque, eccentricity coefficient, radius, equivalent length, bending stiffness and torsional stiffness. It obtains the two-dimensional bending angle based on the feed force, torque, eccentricity coefficient, radius, equivalent length and bending stiffness, obtains the torsion angle based on the torque, equivalent length and torsional stiffness, and obtains the pitch compensation angle and roll compensation angle based on the two-dimensional bending angle and torsion angle. The tilt angle calculation module obtains the corrected pitch angle based on the initial pitch angle, dynamic pitch angle, weighting coefficient, and pitch compensation angle, and obtains the corrected roll angle based on the initial roll angle, dynamic roll angle, weighting coefficient, and roll compensation angle. The hole shaft attitude calculation module obtains the hole shaft tilt angle and hole shaft azimuth angle based on the corrected pitch angle, corrected roll angle and fused azimuth angle. The direction vector generation module obtains the direction vector based on the hole shaft inclination angle and hole shaft azimuth angle.

2. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The initial attitude calculation module performs the following steps: Step S101: Read the mast tilt angle in the first horizontal axis direction of the device coordinate system, the mast tilt angle in the second horizontal axis direction of the device coordinate system, the vehicle tilt angle in the first horizontal axis direction of the local horizontal coordinate system, and the vehicle tilt angle in the second horizontal axis direction of the local horizontal coordinate system. Step S102: Add the mast tilt angle in the first transverse axis direction to the vehicle body tilt angle in the first transverse axis direction to obtain the initial pitch angle; Step S103: Add the mast tilt angle in the second transverse axis direction to the vehicle body tilt angle in the second transverse axis direction to obtain the initial roll angle.

3. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The dynamic tilt angle calculation module performs the following steps: Step S201: Read the triaxial accelerometer, calculate the square root of the sum of squares of the triaxial accelerometer, and obtain the acceleration modulus; Step S202: Divide the acceleration measure of each axis by the acceleration modulus, and invert each ratio to obtain three normalized quantities; Step S203: Obtain the dynamic pitch angle based on the square and square root of the first axial normalization value, the second axial normalization value, and the third axial normalization value; and obtain the dynamic roll angle based on the second axial normalization value and the third axial normalization value. Step S204: Divide the absolute value of the difference between the acceleration modulus and the calibrated gravity by the calibrated gravity to obtain the gravity deviation ratio; Step S205: Take the square root of the sum of the squares of the first and second transverse angular velocities, and then divide by the angular velocity constant to obtain the angular velocity ratio. Step S206: Add the gravity deviation ratio to the angular velocity ratio to obtain the disturbance coefficient. Add one to the disturbance coefficient and calculate the ratio of one to the sum to obtain the weighting coefficient.

4. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The azimuth fusion module performs the following steps: Step S301: Read the historical azimuth angle, vertical angular velocity, and sampling time; add the product of the vertical angular velocity and the sampling time to the historical azimuth angle to obtain the integrated azimuth angle. Step S302: Read the three-axis magnetic field quantity, dynamic pitch angle and dynamic roll angle, and convert the three-axis magnetic field quantity into two horizontal magnetic field quantities according to the dynamic pitch angle and dynamic roll angle; Step S303: Obtain the magnetic azimuth angle based on the two horizontal magnetic field quantities; Step S304: Add the product of the weighting coefficient and the magnetic azimuth sine value, and the product of the difference between one and the weighting coefficient and the integral azimuth sine value to obtain the azimuth sine value; Step S305: Add the product of the weighting coefficient and the magnetic azimuth cosine value, and the product of the difference between the weighting coefficient and the integral azimuth cosine value to obtain the azimuth cosine value. Step S306: Obtain the fused azimuth angle based on the azimuth sine and azimuth cosine.

5. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The bending and torsional compensation calculation module performs the following steps: Step S401: Read the feed force, torque, eccentricity coefficient, radius, equivalent length, elastic modulus, moment of inertia of the first section, moment of inertia of the second section, shear modulus, and polar moment of inertia. Step S402: The product of the eccentricity coefficient and the feed force is used as the feed side force, and the torque is divided by the radius to obtain the torque side force. Step S403: Take the product of the feed side force and the square of the equivalent length as the first numerator, and take the product of the elastic modulus and the moment of inertia of the second section as the first denominator. Calculate the ratio of the first numerator to the first denominator to obtain the first bending angle. Step S404: Take the product of the torque side force and the square of the equivalent length as the second numerator, and take the product of the elastic modulus and the moment of inertia of the first section as the second denominator. Calculate the ratio of the second numerator to the second denominator to obtain the second bending angle. Step S405: Divide the product of torque and equivalent length by the product of shear modulus and polar moment of inertia to obtain the torsion angle; Step S406: Subtract the product of the first camber angle and the cosine of the torsion angle from the product of the second camber angle and the sine of the torsion angle to obtain the pitch compensation angle; add the product of the first camber angle and the sine of the torsion angle to the product of the second camber angle and the cosine of the torsion angle to obtain the roll compensation angle.

6. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The tilt angle calculation module performs the following steps: Step S501: The product of the weighting coefficient and the dynamic pitch angle is used as the first pitch value; Step S502: The product of the difference between the first and second weighting coefficients and the initial pitch angle is used as the second pitch value; Step S503: Add the first pitch value, the second pitch value, and the pitch compensation angle to obtain the corrected pitch angle; Step S504: The product of the weighting coefficient and the dynamic roll angle is used as the first roll amount. Step S505: The product of the difference between the first and second weighting coefficients and the initial roll angle is used as the second roll amount. Step S506: Add the first roll amount, the second roll amount, and the roll compensation angle to obtain the corrected roll angle.

7. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The hole shaft attitude calculation module performs the following steps: Step S601: Calculate the product of the corrected pitch angle tangent and the blended azimuth cosine, and calculate the product of the corrected roll angle tangent and the blended azimuth sine. Subtract the two products to obtain the first slope. Step S602: Calculate the product of the corrected pitch angle tangent and the blended azimuth angle sine, and calculate the product of the corrected roll angle tangent and the blended azimuth angle cosine. Add the two products together to obtain the second slope value. Step S603: Calculate the square root of the sum of the squares of the first slope and the squares of the second slope. Step S604: Calculate the arctangent of the square root to obtain the hole shaft inclination angle; Step S605: Perform bivariate arctangent calculation based on the first slope and the second slope to obtain the hole axis azimuth angle.

8. The device for accurately measuring the attitude of a drilling rig according to claim 1, characterized in that, The direction vector generation module performs the following steps: Step S701: The product of the sine of the hole shaft inclination angle and the sine of the hole shaft azimuth angle is taken as the eastward component of the direction vector; Step S702: The product of the sine of the hole shaft inclination angle and the cosine of the hole shaft azimuth angle is taken as the north component of the direction vector; Step S703: Use the cosine value of the hole shaft inclination angle as the upward component of the direction vector; Step S704: Combine the eastward component, northward component, and upward component into a direction vector.

9. A method for accurately measuring the attitude of a drilling rig, characterized in that, Performing the apparatus for accurately measuring drilling rig attitude as described in any one of claims 1 to 8 includes the following steps: Step S1: Read the mast tilt angle and the vehicle tilt angle, and add them together to obtain the initial pitch angle and the initial roll angle; Step S2: Read the acceleration measurement and lateral angular velocity, obtain the dynamic pitch angle and dynamic roll angle based on the acceleration measurement, and obtain the weighting coefficient based on the acceleration measurement, calibrated gravity and lateral angular velocity. Step S3: Read the historical azimuth angle, vertical angular velocity, magnetic field quantity and time; obtain the integral azimuth angle based on the historical azimuth angle, vertical angular velocity and time; obtain the magnetic azimuth angle based on the magnetic field quantity, dynamic pitch angle and dynamic roll angle; obtain the fused azimuth angle based on the integral azimuth angle, magnetic azimuth angle and weighting coefficient. Step S4: Read the feed force, torque, eccentricity coefficient, radius, equivalent length, bending stiffness and torsional stiffness. Obtain the two-dimensional bending angle based on the feed force, torque, eccentricity coefficient, radius, equivalent length and bending stiffness. Obtain the torsion angle based on the torque, equivalent length and torsional stiffness. Obtain the pitch compensation angle and roll compensation angle based on the two-dimensional bending angle and torsion angle. Step S5: Obtain the corrected pitch angle based on the initial pitch angle, dynamic pitch angle, weighting coefficient, and pitch compensation angle; obtain the corrected roll angle based on the initial roll angle, dynamic roll angle, weighting coefficient, and roll compensation angle. Step S6: Obtain the hole axis tilt angle and hole axis azimuth angle based on the corrected pitch angle, corrected roll angle, and blended azimuth angle; Step S7: Obtain the direction vector based on the hole shaft inclination angle and hole shaft azimuth angle.

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