Recording type MEMS (Micro Electro Mechanical System) gyro inclinometer

Abstract

The invention relates to the field of inclinometer equipment, in particular to a recording type MEMS (Micro Electro Mechanical System) gyro inclinometer which comprises an MEMS gyro inclinometer body, when the MEMS gyro inclinometer body is electrified and initialized, different north-seeking modes are selected according to whether a north-seeking instruction is received or not, the MEMS gyro inclinometer body enters an inclinometer state, and a true north position is determined by resolving an earth rotation angular velocity component and original sensor output data; performing error compensation calculation on the original sensor output data according to a preset error compensation model, and outputting accurate sensor output data; in the working process, the motion state is judged according to the output data of the sensor, and the accurate output data of the sensor is continuously updated and corrected through an online automatic correction strategy; and the damping structure module is detachably connected with the MEMS gyro inclinometer body and is used for adapting to different underground tandem connection environments. The combined sensor is adopted, and the intelligent north-seeking algorithm and the error compensation model are combined, so that high-precision inclination measurement in a magnetic interference environment is realized, and the measurement precision and the environmental adaptability are improved.

Description

Technical Field

[0001] This invention relates to the field of inclinometer equipment, and more specifically to a recording MEMS gyroscope inclinometer. Background Technology

[0002] In fields such as oil drilling, geological exploration, and coal mining, inclinometers are key equipment for measuring borehole trajectory parameters. They can monitor the inclination and azimuth angles of the wellbore in real time, providing important data support for drilling guidance and geological analysis. With the continuous development of drilling technology, higher requirements are placed on the measurement accuracy, adaptability, and reliability of inclinometers.

[0003] Traditional inclinometers mainly employ a combination of fluxgate magnetometers and quartz accelerometers. Chinese patent CN120141404A discloses an integrated gyro attitude meter for directional inclinometers in coal mines, utilizing MEMS gyroscopes and MEMS accelerometers to achieve a small-size structure. It employs an improved initial alignment algorithm, including coarse alignment and Kalman filtering for fine alignment, achieving high-precision orientation throughout space based on satellite injection parameters. Chinese patent CN105910626B discloses a full-temperature calibration compensation method for north-finding inclinometers using a flexible gyro. This method calibrates 52 rotational positions of a three-axis calibration device at different temperatures, using the least squares method to derive the error coefficients of the accelerometer and gyroscope. Chinese patent CN104389584B discloses a high-speed continuous gyro inclinometer system, including an inertial body, probe circuitry, and a pressure-resistant outer shell assembly, achieving automatic north-finding and high-precision, high-speed continuous measurement of wellbore parameters. Chinese patent CN116539065B discloses a calibration and correction method for a gyro inclinometer, establishing a zero-bias calibration model, a scale calibration model, an orthogonal model, and a different-axis model to form a comprehensive calibration and correction model to reduce measurement errors. Chinese patent CN107228664A discloses a method for attitude calculation and zero-velocity correction of a strapdown inertial navigation system for a mining gyro inclinometer, solving the mechanical arrangement equations using the Runge-Kutta method and employing a zero-velocity correction algorithm to eliminate accumulated errors.

[0004] However, existing technologies still have the following shortcomings: First, existing technologies mainly rely on the geomagnetic field for azimuth measurement. In magnetic mining areas or environments with magnetic interference, the measurement results will be significantly affected, leading to increased measurement errors and limiting their application in complex geological environments. Second, existing technologies generally use triaxial fluxgate magnetometers and triaxial quartz accelerometers, which have large sensor sizes, require positive and negative power supplies, have complex power supply designs, and output analog signals that require external AD conversion circuits, resulting in a large and complex overall signal conditioning circuit design. Third, existing technologies mostly use mud pulse transmission, which has a relatively low transmission rate, generally only reaching 4-10 bits / s, making it impossible to transmit large amounts of observation data from downhole to the surface, affecting the real-time performance and completeness of data acquisition. In addition, the same product cannot adapt to wellbore diameters and cannot be simultaneously applied to different application scenarios such as drilling while drilling and drop wire, limiting the product's versatility and economy. Summary of the Invention

[0005] To address the technical challenges of existing technologies, such as increased measurement errors in magnetic mining environments, large sensor size and complex power supply, low data transmission rates, and poor product adaptability, this application provides a recording-type MEMS gyroscope inclinometer. By replacing traditional magnetic sensors with MEMS gyroscopes and utilizing the Earth's rotational angular velocity component for true north determination, it fundamentally avoids the impact of magnetic interference on measurement accuracy. Furthermore, through an innovative error compensation model and online automatic correction strategy, dynamic compensation for MEMS sensor system errors is achieved, ensuring high-precision measurements even in complex downhole environments.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows: A recording-type MEMS gyro inclinometer is provided, comprising: a MEMS gyro inclinometer body, used to perform: upon power-on initialization, selecting different north-finding modes based on whether a north-finding command is received, and entering an inclinometer state; determining true north by calculating the Earth's rotation angular velocity component and the original sensor output data; performing error compensation calculations on the original sensor output data according to a preset error compensation model, and outputting accurate sensor output data; during operation, judging the motion state based on the sensor output data, and continuously updating and correcting the accurate sensor output data through an online automatic correction strategy; and a shock-absorbing structural module, detachably connected to the MEMS gyro inclinometer body, for adapting to different downhole serial connection environments.

[0007] Optionally, the shock-absorbing structural module includes: a replaceable connector to adapt to different numbers of cores, a shock-absorbing pad to adapt to different diameter requirements, and a variable joint to adapt to different length requirements.

[0008] Optionally, the shock-absorbing pad has a segmented structure, including at least four independent vibration damping units, which are respectively disposed between the connector at the front end and the variable joint at the front end, between the variable joint at the front end and the MEMS gyroscope inclinometer body, between the MEMS gyroscope inclinometer body and the variable joint at the rear end, and between the variable joint at the rear end and the connector at the rear end.

[0009] Optionally, the MEMS gyroscope inclinometer body includes: a sensor module comprising a three-axis MEMS gyroscope and a three-axis MEMS accelerometer for acquiring raw sensor output data; and a control module comprising: a judgment submodule, a north-finding submodule, an automatic north-finding submodule, and an online automatic calibration submodule; wherein, the judgment submodule is used to read the preset north-finding configuration information in the storage module during power-on initialization, and after reading, to determine whether there is a north-finding command. If a north-finding command is received, it decodes the command and performs the north-finding process according to the north-finding method, time, latitude, longitude, and altitude parameters required by the command; if no north-finding command is received, it performs the automatic north-finding process according to the preset north-finding configuration information in the storage module; the north-finding submodule is used to enter the inclinometer state after starting the north-finding process, and calculates the Earth's rotation angular velocity component and raw sensor data. The system uses the sensor output data and the latitude, longitude, and altitude parameters in the north-finding command to determine true north. Based on a preset error compensation model, it performs error compensation calculations on the original sensor output data, outputting accurate sensor data. The self-north-finding submodule initiates the self-north-finding process by calculating the Earth's rotation angular velocity component, the original sensor output data, and the preset north-finding configuration information in the storage module to determine true north. Based on the preset error compensation model, it performs error compensation calculations on the original sensor output data, outputting accurate sensor data. The online automatic calibration submodule determines the motion state based on the sensor output data during operation and continuously updates and corrects the accurate sensor output data using an online automatic correction strategy. The storage module records the original sensor output data, accurate sensor output data, and correction event logs in real time.

[0010] Optionally, the online automatic correction strategy includes: during operation, judging the motion state based on sensor output data; when a static state is continuously detected for more than a first preset time, triggering attitude realignment; when a static state is continuously detected for more than a second preset time, incrementally updating the internal error compensation parameters using static data.

[0011] Optionally, when the online automatic calibration submodule triggers attitude realignment, it also responds to any of the following conditions: the angular velocity of any axis exceeds the gyroscope range; or the non-zero velocity duration during north-finding or self-north-finding exceeds half of the total north-finding time.

[0012] Optionally, the incremental update includes: refitting the triaxial MEMS accelerometer installation error matrix using accurate accelerometer output data during the static period; recalculating the gyroscope zero-bias drift using accurate gyroscope output data during the static period; and writing the updated internal error compensation parameters into the error compensation model for subsequent attitude calculation.

[0013] Optionally, the error compensation model includes: gyroscope scaling coefficient, gyroscope zero bias, gyroscope installation error, accelerometer scaling coefficient, accelerometer zero bias, accelerometer installation error, accelerometer quadratic scaling term, accelerometer lever arm error, and gyroscope-accelerometer synchronization error; the error compensation model is obtained through calibration using a temperature chamber turntable device and written into a storage module.

[0014] Optionally, the data recorded by the storage module includes: original gyroscope output data and original accelerometer output data; compensated heading angle, compensated roll angle and compensated pitch angle; correction event type, trigger time, and internal error compensation parameter values ​​before and after the update.

[0015] Optionally, it also includes: an external DC power supply, wherein the external DC power supply input is converted by a secondary power supply circuit to power the sensor module, the control module and the storage module; the control module acquires sensor output data through the SPI bus and outputs data to the storage module and external devices through the UART bus.

[0016] The invention provides a recording-type MEMS gyro inclinometer with the following advantages: strong environmental adaptability, applicable to magnetic mines, solving the problem of decreased inclinometer accuracy due to magnetic interference in magnetically sensitive inclinometers; not limited by data transmission rate, capable of recording over 1000 hours of data internally, solving the problem of small recorded data volume due to low mud pulse transmission rate; accurate reproduction of drilling trajectory, with more comprehensive and abundant internally recorded data compared to data transmitted to ground observation stations, allowing for accurate reproduction of the drilling trajectory after post-processing; unrestricted use in probes with diameters of 35mm, 38mm, and 48mm, solving the problem of the same product being unable to adapt to wellbore diameters; usable both while drilling and via cable, addressing the need for the same product to be suitable for both scenarios; and capable of achieving closed-loop high-precision attitude maintenance of "autonomous perception-autonomous decision-making-autonomous correction" without relying on external equipment or interrupting operations, even in complex environments with high downhole vibration and inconsistent equipment connection lengths / diameters, while ensuring long-term structural stability. Attached Figure Description

[0017] The accompanying drawings, which are provided to further illustrate this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application.

[0018] Figure 1 This is a schematic diagram of the recording MEMS gyroscope inclinometer of the present invention.

[0019] Figure 2 This is a structural framework diagram of the MEMS gyroscope inclinometer body of the present invention.

[0020] Figure 3 This is a structural framework diagram of the control module of the present invention.

[0021] Figure 4 This is the overall flowchart of the present invention.

[0022] Figure description: Connector 1, shock absorber 2, variable joint 3, MEMS gyroscope inclinometer body 4. Detailed Implementation

[0023] The embodiments of this application will now be described in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, the following embodiments and features can be combined with each other unless otherwise specified. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] Example 1

[0025] Please see Figure 1 This embodiment provides a recording MEMS gyroscope inclinometer. The recording MEMS gyroscope inclinometer comprises two main parts: the MEMS gyroscope body 4 and a shock-absorbing structural module. Through modular design, it achieves an organic combination of high-precision inclinometer measurement and multi-environment adaptability.

[0026] Please see Figure 2 The MEMS gyroscope inclinometer body 4 serves as the core measurement unit, integrating a sensor module, a control module, and a storage module. The sensor module is equipped with a three-axis MEMS gyroscope and a three-axis MEMS accelerometer. The three-axis MEMS gyroscope detects angular velocity signals around three orthogonal axes, while the three-axis MEMS accelerometer measures acceleration components in three orthogonal directions. Working together, they achieve omnidirectional perception of spatial attitude. The control module establishes a high-speed data communication link with the sensor module via an SPI bus, acquiring sensor output data in real time to ensure the real-time performance and accuracy of data transmission.

[0027] In one embodiment of this application, the three-axis MEMS gyroscope operates based on the Coriolis force principle. As the device rotates with the Earth, the three-axis MEMS gyroscope can detect the horizontal component of the Earth's rotational angular velocity. The three-axis MEMS accelerometer determines the tilt angle by measuring the gravitational acceleration component. The sensor module uses a digital output interface to directly output the digital signal after analog-to-digital conversion, avoiding interference during analog signal transmission.

[0028] Please see Figure 3 The control module can be an MCU microcontroller, internally divided into four functional sub-modules, each performing its own processing tasks at different stages. The judgment sub-module starts first during the system power-on initialization phase, reading the preset north-finding configuration information from the storage module. This configuration information includes the default north-finding mode, north-finding time, and latitude / longitude parameters. After reading, the judgment sub-module monitors the reception status of external north-finding commands. When a north-finding command is detected, it decodes the received command data, extracting key information such as the specified north-finding mode, north-finding time, and latitude / longitude parameters, and then initiates the corresponding north-finding process. If no external north-finding command is received within the preset time window, the judgment sub-module automatically calls the internal preset north-finding configuration information and initiates the self-north-finding process, ensuring that the system can complete initial orientation under any circumstances.

[0029] Upon receiving an external north-finding command, the north-finding submodule takes over the subsequent processing. First, it enters inclinometer mode, using a three-axis MEMS gyroscope to detect the local angular velocity component of the Earth's rotation. Combining this with the original sensor output data and the precise latitude, longitude, and altitude parameters carried in the north-finding command, it determines true north through mathematical calculations. After obtaining the true north reference, the north-finding submodule invokes a pre-set error compensation model. This model includes multiple internal error compensation parameters, such as gyroscope scaling coefficients, gyroscope bias, gyroscope installation error, accelerometer scaling coefficients, accelerometer bias, accelerometer installation error, accelerometer quadratic scaling term, accelerometer lever error, and gyroscope-accelerometer synchronization error. These parameters are obtained through calibration of the temperature chamber turntable and pre-written into the storage module. The north-finding submodule uses this error compensation model to perform comprehensive error compensation calculations on the original sensor output data, effectively eliminating the influence of various systematic errors and outputting high-precision compensated attitude data.

[0030] When the self-north-finding mode is used, the self-north-finding submodule undertakes the corresponding processing tasks. The working principle of the self-north-finding submodule is basically the same as that of the north-finding submodule, the difference being that it uses preset north-finding configuration information stored in the storage module to replace the parameters in the external commands. The self-north-finding submodule also determines true north by calculating the Earth's rotation angular velocity component, the raw sensor output data, and the internally configured latitude and longitude information, and uses the same error compensation model to process the raw data, outputting accurate sensor data.

[0031] During the north-seeking / self-north-seeking process, the Earth's rotational angular velocity We, where We = 15.041° / h, is parallel to the Earth's rotational axis. At latitude L on the Earth's surface, the Earth's rotational angular velocity We can be decomposed into a horizontal component Wn along the meridian Yn and a vertical component Wu along the perpendicular Zn, expressed as follows: and .

[0032] By accurately outputting data from the gyroscope and accelerometer, the heading angle, roll angle, and pitch angle are calculated. Furthermore, the specific formulas for calculating the azimuth angle, high-side toolface angle, and well inclination angle for well inclination measurements are as follows: , , ,in, Let G be the attitude matrix and G be the gravity. The above three equations are used to calculate... ; ,in, The well inclination angle, in, For the high-side tool face angle; ,in, It is the azimuth angle; This represents the data in the i-th row and j-th column of the attitude matrix. Specifically, This is the data in the 3rd row and 2nd column of the attitude matrix. This is the data in the 3rd row and 1st column of the attitude matrix. This is the data in the 3rd row and 3rd column of the attitude matrix. This is the data in the first row and second column of the attitude matrix. This is the data in the second row and second column of the attitude matrix.

[0033] A three-axis MEMS gyroscope is a sensor that measures the angular velocity around its sensitive axis. When the gyroscope is mounted vertically on a horizontal plane, with its sensitive axis Yg parallel to north (true north) in the geographic coordinate system, the angular velocity W0 sensed by the gyroscope is the horizontal component Wn of We. When the sensitive axis Yg of the gyroscope forms an angle α with true north in the horizontal plane in a counterclockwise direction, the gyroscope's output W0 is the projection Wg of the horizontal component of We onto the gyroscope's sensitive axis, as shown in the formula: .

[0034] Once the gyroscope's output at the corresponding orientation is measured, the angle α between the gyroscope's sensitive axis and true north at that location can be calculated. The calculation formula is as follows: The error compensation model consists of two parts: the gyroscope error compensation model and the accelerometer error compensation model.

[0035] In a preferred embodiment, the calculation formula for the gyroscope error compensation model includes: , ,in, The value of i here is x, y, or z (representing the three orthogonal axes), which is the result of the calculation process after the original gyroscope output is corrected in the first step. This is the original gyroscope output data; These are the gyroscope scaling coefficients; This is the zero-position compensation value for the gyroscope; This is the gyroscope installation error coefficient, where i takes the value of 1, 2, or 3, and j takes the value of 1, 2, or 3. , , To accurately output data for a gyroscope containing three orthogonal axes (x, y, z).

[0036] In a preferred embodiment, the calculation formula for the accelerometer error compensation model includes: , , ,in, The value of i here is x, y, or z (representing the three orthogonal axes), which is the result of the calculation process after the original acceleration output is corrected in the first step. This provides the raw accelerometer output data. For accelerometer scaling factors; This is the zero-point compensation value for the accelerometer; This is the accelerometer installation error coefficient, where i takes the value of 1, 2, or 3, and j takes the value of 1, 2, or 3. These are the coefficients of the quadratic term of the accelerometer scale; This is the error compensation value for the accelerometer lever arm; This is the compensation value for the synchronization error between the gyroscope and the accelerometer; To ensure accurate data output from the accelerometer.

[0037] The online automatic calibration submodule runs continuously throughout the entire operation, enabling dynamic maintenance of measurement accuracy. This submodule continuously monitors sensor output data, analyzing the changes in acceleration and angular velocity to determine the device's motion state. The online automatic calibration submodule employs a multi-layered automatic correction strategy: when a static state is continuously detected for more than a first preset duration (e.g., 3 seconds), the system determines that the device is in a stable, stationary state, triggering a realignment procedure to prevent accidental movement (being moved); when a static state is continuously detected for more than a second preset duration (e.g., 80 seconds), the online automatic calibration submodule initiates a deeper calibration mechanism, incrementally updating internal error compensation parameters using the statistical characteristics of long-term static data to prevent drift (long periods of shaking or large amplitude of shaking). It should be noted that the second preset duration (e.g., 80 seconds) involved in this application is used for online calibration, not for "output filtering." This "dual-threshold online compensation" automatic correction strategy, by establishing a "dynamic triggering-static optimization" closed-loop mechanism, differs from traditional automatic correction that relies solely on static detection or filter switching technology. It enables dynamic compensation during product operation, thereby improving the long-term accuracy of the product.

[0038] The online automatic calibration submodule also has the ability to detect abnormal states. When it detects that the angular velocity of any axis exceeds the range of the gyroscope or that the non-zero velocity duration during the north-finding process exceeds half of the total north-finding time, it determines that there is abnormal interference in the current measurement environment and automatically triggers the attitude realignment program to ensure the reliability of the measurement results.

[0039] The incremental update process involves several refined calibration steps: First, using the output data of the accelerometer during the static period, the installation error matrix of the triaxial MEMS accelerometer can be refitted using mathematical methods such as the least squares method to eliminate the inter-axis coupling error generated during installation; second, using the output data of the gyroscope during the static period, the gyroscope zero-bias drift can be recalculated using methods such as long-term integral averaging to compensate for the zero-bias changes caused by temperature variations and device aging; finally, the updated internal error compensation parameters are written into the error compensation model, replacing the original parameters for subsequent attitude calculations, thereby achieving adaptive optimization of the compensation model.

[0040] The storage module, acting as the data management center, utilizes eMMC storage chips to record all critical information during system operation in real time. Stored data types include: raw gyroscope and accelerometer output data, providing foundational data support for subsequent data analysis and algorithm optimization; accurate gyroscope and accelerometer output data, directly reflecting the device's spatial attitude information; and log information such as correction event types, trigger times, and compensation parameter values ​​before and after updates, providing detailed event traceability records for system maintenance and fault diagnosis. The control module outputs processed data to the storage module and external devices via a UART bus, achieving efficient data transmission and sharing.

[0041] In addition, this recording MEMS gyroscope inclinometer also includes an external DC power supply (such as 9-36V). The external DC power input is converted into the required 3.3V and 5V power supplies by the internal secondary power supply circuit to power the internal sensor module, control module and storage module.

[0042] The shock-absorbing structural module is integrated with the MEMS gyro inclinometer body 4 via a detachable connection, providing a flexible adaptation solution for different downhole serial connection environments. This shock-absorbing structural module adopts a modular design concept and includes three types of replaceable components: replaceable connector 1 can adapt to electrical connection requirements with different core counts, and the appropriate connector 1 model can be selected according to the interface specifications of the downhole equipment; adaptable shock-absorbing pads 2 can provide corresponding diameter specifications according to different well diameter requirements, ensuring stable installation of the equipment downhole; and adaptable variable joints 3 can provide different length specifications to meet various serial connection length requirements.

[0043] The vibration damping pad 2 adopts a segmented structural design, comprising four independent vibration damping units to achieve comprehensive vibration damping protection for the entire recording MEMS gyro inclinometer. The first vibration damping unit is located between the connector 1 and the variable joint 3 at the front end, primarily absorbing vibration shocks transmitted from the front equipment. The second vibration damping unit is located between the variable joint 3 at the front end and the MEMS gyro inclinometer body 4, providing front-end vibration isolation protection for the core measurement unit. The third vibration damping unit is located between the MEMS gyro inclinometer body 4 and the variable joint 3 at the rear end, isolating vibration transmission between the body and the rear structure. The fourth vibration damping unit is located between the variable joint 3 at the rear end and the connector 1 at the rear end, completing the tail-end protection of the entire vibration damping chain. The four vibration damping units work together to form a complete vibration damping system, effectively reducing the impact of mechanical vibration in the complex downhole environment on the high-precision MEMS sensor, ensuring the stability and accuracy of the measurement data. It should be noted that different damping materials can be selected for the vibration damping units depending on the different structural hardness / thickness of each section to be connected. For example, the damping materials for the first and fourth vibration damping units can be elastic metal springs (such as cantilever disc springs), while the second and third vibration damping units can be aluminum alloy rigid brackets and high-damping rubber (such as silicone rubber with a Shore hardness of 70A) wrapping the aluminum alloy rigid brackets, forming a multi-level physical property synergistic damping structure, which can further significantly reduce the coupling interference of high-frequency vibration on the recording MEMS gyroscope inclinometer and improve the stability of static data.

[0044] In one embodiment of this application, connector 1 can be selected with different core counts according to actual application requirements, including common configurations such as 7 cores, 12 cores, and 19 cores, to adapt to different signal transmission and power supply requirements.

[0045] In one embodiment of this application, the diameter of the shock-absorbing pad 2 can be selected according to the well diameter. Typical diameter ranges include 60mm, 80mm, 100mm and other specifications, to ensure stable installation and effective shock absorption in wells of different diameters.

[0046] In one embodiment of this application, the length of the variable connector 3 can be adjusted according to the serial connection requirements. The length range is usually between 50mm and 200mm. The length can be flexibly adjusted by threaded connection or snap-fit ​​to meet the space requirements of downhole operations of different depths and complexities.

[0047] In one embodiment of this application, the vibration damping unit between the connector 1 at the front end and the variable joint 3 at the front end has a diameter of 80 mm and a thickness of 15 mm; the vibration damping unit between the variable joint 3 at the front end and the MEMS gyroscope inclinometer body 4 has a diameter of 75 mm and a thickness of 20 mm; the vibration damping unit between the MEMS gyroscope inclinometer body 4 and the variable joint 3 at the rear end has a diameter of 75 mm and a thickness of 20 mm; and the vibration damping unit between the variable joint 3 at the rear end and the connector 1 at the rear end has a diameter of 80 mm and a thickness of 15 mm.

[0048] The entire recording MEMS gyro inclinometer utilizes a modular design with shock-absorbing structural modules, enabling flexible adaptation to different downhole operating environments. The replaceable connector 1 design allows the instrument to connect to drill strings of various sizes; the variable-length joint design meets installation requirements for different space dimensions; and the segmented shock-absorbing pad 2 design provides targeted protection based on the vibration characteristics of each part of the instrument, significantly improving the measurement accuracy and reliability of the recording MEMS gyro inclinometer in harsh downhole environments.

[0049] Example 2

[0050] This embodiment, based on Embodiment 1 above, provides a measurement method using a recording MEMS gyroscope inclinometer. Please refer to [link to previous document]. Figure 4 The specific implementation steps are as follows.

[0051] S1, System initialization.

[0052] During power-on initialization, the judgment submodule reads the preset north-finding configuration information from the storage module. After reading, it checks whether there is a north-finding command. If a north-finding command is received, the judgment submodule decodes the command and starts the north-finding process according to the north-finding method, time, latitude, longitude, and altitude parameters required by the command. If no north-finding command is received, the self-north-finding process starts according to the preset north-finding configuration information in the storage module.

[0053] According to the normal working process of the recording MEMS gyroscope inclinometer, a quick and accurate north-finding measurement only takes 150 seconds. After the north-finding is completed, the product enters the inclinometer working state and outputs accurate data from the sensor in real time.

[0054] In one embodiment of this application, a series of comprehensive tests were conducted using a 150s static north-finding method as the research object. The technical specifications of this recording MEMS gyroscope inclinometer are: well inclination angle error of 0.1° (1σ), high-side tool face angle error of 0.1° (1σ), and well inclination azimuth angle of 1° (1σ).

[0055] S2, Sensor output data acquisition.

[0056] The sensor module contains a three-axis MEMS gyroscope and a three-axis MEMS accelerometer that continuously acquire sensor output data, including three-axis angular velocity data and three-axis acceleration data. The storage module records the raw gyroscope output data and raw accelerometer output data in real time.

[0057] S3, Error Compensation Calculation.

[0058] The error compensation model includes gyroscope scaling coefficients, gyroscope zero bias, gyroscope installation error, accelerometer scaling coefficients, accelerometer zero bias, accelerometer installation error, accelerometer quadratic scaling term, accelerometer lever arm error, and gyroscope-accelerometer synchronization error. This error compensation model is obtained through calibration using a temperature chamber turntable and written into a storage module. It is used to compensate for the original sensor output data, ensuring accurate sensor output.

[0059] S4. The sensor accurately outputs data.

[0060] After error compensation calculation, the compensated heading angle, roll angle, and pitch angle are output. The storage module records the accurate output data from these sensors.

[0061] S5. Execute the north-finding process.

[0062] Once the north-finding process is initiated, the north-finding submodule enters the inclinometer mode. It determines true north by calculating the Earth's rotation angular velocity component, the raw sensor output data, and the latitude, longitude, and altitude parameters in the north-finding command. The north-finding submodule then performs error compensation calculations on the raw sensor output data based on a preset error compensation model.

[0063] S6. Execute the self-north-finding process.

[0064] When the self-north-finding process is initiated, the self-north-finding submodule determines the true north direction by calculating the Earth's rotation angular velocity component, the raw sensor output data, and the preset north-finding configuration information (i.e., latitude, longitude, and altitude parameters) stored in the storage module. The self-north-finding submodule then performs error compensation calculations on the raw sensor output data according to a preset error compensation model.

[0065] S7, motion status monitoring.

[0066] During operation, the online automatic calibration submodule determines the motion state based on sensor output data. When a static state is continuously detected for more than a first preset time, it triggers attitude realignment; when a static state is continuously detected for more than a second preset time, it incrementally updates the internal error compensation parameters using static data.

[0067] S8, readjust the posture.

[0068] When the angular velocity of any axis exceeds the gyroscope's range, or when the duration of non-zero velocity during north-finding / self-north-finding exceeds half of the total north-finding time, attitude realignment is triggered. The online automatic calibration submodule continuously updates and corrects the accurate sensor output data through an online automatic correction strategy.

[0069] S9, Incremental update processing.

[0070] Using accurate accelerometer output data during the static period, the installation error matrix of the triaxial MEMS accelerometer is refitted; using accurate gyroscope output data during the static period, the gyroscope zero-bias drift is recalculated. The updated internal error compensation parameters are written into the error compensation model for subsequent attitude calculation.

[0071] S10, Data Recording and Log Management.

[0072] The storage module records the type of correction event, the trigger time, and the internal error compensation parameter values ​​before and after the update, forming a complete correction event log. This data provides an important basis for the long-term stable operation and performance evaluation of the system.

[0073] This measurement method achieves high-precision attitude measurement through the coordinated operation of the sensor module, control module, and storage module of the MEMS gyro inclinometer body 4. The judgment submodule, north-finding submodule, self-north-finding submodule, and online automatic calibration submodule within the control module each perform their respective functions, ensuring that the system can automatically select the appropriate working mode according to different operating conditions. Furthermore, it continuously optimizes measurement accuracy through an online automatic correction strategy, effectively solving the technical problems of accuracy degradation and long-term drift in traditional inclinometers under complex environments.

[0074] The functions described above in this document can be performed at least in part by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), etc.

[0075] Obviously, those skilled in the art will understand that the various steps of the present invention described above can be performed in a manner different from that described above, and the simulation methods and experimental equipment include, but are not limited to, the above description. The steps of the present invention described above can be performed in a different order in certain circumstances, and the steps shown or described above can be performed separately. Therefore, the present invention is not limited to any particular combination of hardware and software.

[0076] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered within the scope of protection of the present invention.

Claims

1. A recording-type MEMS gyroscope inclinometer, characterized in that, include: The MEMS gyro inclinometer body is used to perform: During power-on initialization, different north-finding modes are selected depending on whether a north-finding command is received, and the inclinometer state is entered. The true north direction is determined by calculating the Earth's rotation angular velocity component and the original sensor output data. Based on the preset error compensation model, error compensation calculations are performed on the original sensor output data to output accurate sensor output data. During operation, the motion state is determined based on the sensor output data, and the online automatic correction strategy continuously updates and corrects the accurate sensor output data. The shock-absorbing structural module is detachably connected to the MEMS gyro inclinometer body to adapt to different downhole serial connection environments.

2. The recording-type MEMS gyroscope inclinometer as described in claim 1, characterized in that, The shock-absorbing structural module includes: a replaceable connector to accommodate different numbers of cores, a shock-absorbing pad to accommodate different diameter requirements, and a variable joint to accommodate different length requirements.

3. The recording-type MEMS gyroscope inclinometer as described in claim 2, characterized in that, The shock-absorbing pad has a segmented structure, including at least four independent vibration damping units, which are respectively located between the connector at the front end and the variable joint at the front end, between the variable joint at the front end and the MEMS gyroscope inclinometer body, between the MEMS gyroscope inclinometer body and the variable joint at the rear end, and between the variable joint at the rear end and the connector at the rear end.

4. The recording-type MEMS gyroscope inclinometer as described in claim 1, characterized in that, The MEMS gyroscope inclinometer body includes: The sensor module, which includes a three-axis MEMS gyroscope and a three-axis MEMS accelerometer, is used to acquire raw sensor output data. The control module includes: a judgment submodule, a north-finding submodule, a self-north-finding submodule, and an online automatic calibration submodule; among which, The judgment submodule is used to read the preset north-finding configuration information in the storage module during power-on initialization. After reading, it determines whether there is a north-finding command. If a north-finding command is received, it decodes the command and performs the north-finding process according to the north-finding method, time, latitude and longitude parameters required by the command. If no north-finding command is received, it performs the self-north-finding process according to the preset north-finding configuration information in the storage module. The north-finding submodule is used to enter the inclinometer state after starting the north-finding process. It determines the true north direction by solving the Earth's rotation angular velocity component, the original sensor output data, and the latitude, longitude, and altitude parameters in the north-finding command. According to the preset error compensation model, it performs error compensation calculation on the original sensor output data and outputs accurate sensor output data. The self-north-finding submodule is used to initiate the self-north-finding process. It determines the true north direction by calculating the Earth's rotation angular velocity component, the original sensor output data, and the preset north-finding configuration information in the storage module. According to the preset error compensation model, it performs error compensation calculation on the original sensor output data and outputs accurate sensor output data. The online automatic calibration submodule is used to determine the motion state based on the sensor output data during operation, and to continuously update and correct the accurate sensor output data through an online automatic correction strategy. The storage module is used to record raw sensor output data, accurate sensor output data, and correction event logs in real time.

5. A recording-type MEMS gyroscope inclinometer as described in claim 4, characterized in that, The online automatic correction strategy includes: During operation, the motion state is determined based on the sensor output data. When a static state is continuously detected for more than a first preset time, the posture is re-aligned. When the static state is continuously detected for more than the second preset time, the internal error compensation parameters are incrementally updated using static data.

6. A recording-type MEMS gyroscope inclinometer as described in claim 5, characterized in that, When the attitude realignment is triggered, the online automatic calibration submodule also responds to any of the following conditions: The angular velocity along any axis exceeds the range of the gyroscope. The time spent at non-zero speed during the north-seeking or self-north-seeking process exceeds half of the total north-seeking time.

7. A recording-type MEMS gyroscope inclinometer as described in claim 5, characterized in that, The incremental update includes: By utilizing the accurate output data of the accelerometer during the static period, the installation error matrix of the triaxial MEMS accelerometer is refitted; By utilizing the accurate output data of the gyroscope during the static period, the zero-bias drift of the gyroscope is recalculated; The updated internal error compensation parameters are written into the error compensation model for subsequent attitude calculation.

8. A recording-type MEMS gyroscope inclinometer as described in claim 7, characterized in that, The error compensation model includes: gyroscope scaling coefficient, gyroscope zero bias, gyroscope installation error, accelerometer scaling coefficient, accelerometer zero bias, accelerometer installation error, accelerometer quadratic scaling term, accelerometer lever arm error, and gyroscope-accelerometer synchronization error. The error compensation model is obtained through calibration using a temperature chamber turntable device and written into the storage module.

9. A recording-type MEMS gyroscope inclinometer as described in claim 4, characterized in that, The data recorded by the storage module includes: Raw gyroscope output data and raw accelerometer output data; The gyroscope and accelerometer output data accurately. Correct the event type, trigger time, and internal error compensation parameter values ​​before and after the update.

10. A recording-type MEMS gyroscope inclinometer as described in claim 4, characterized in that, It also includes: an external DC power supply, which is converted by a secondary power supply circuit to power the sensor module, control module and storage module; the control module collects sensor output data through the SPI bus and outputs data to the storage module and external devices through the UART bus.

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