Shallow sea magnetotelluric acquisition station capable of automatically correcting orientation
By setting up MEMS inertial measurement units and automatic correction units in the seabed electromagnetic acquisition station, the sensor orientation was adjusted, solving the orientation deviation problem caused by marine environmental factors and achieving high accuracy and reliability of seabed electromagnetic detection data.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-23
- Publication Date
- 2026-03-31
AI Technical Summary
In existing seabed electromagnetic detection technologies, the electric and magnetic field sensors are subject to azimuth shifts due to factors such as ocean current impacts and deployment angle deviations, resulting in azimuth deviations in the observation data. Existing software compensation methods suffer from error accumulation, affecting data accuracy.
The attitude of the data acquisition station is detected by a MEMS inertial measurement unit, the orientation of the electric and magnetic field sensors is adjusted by an automatic correction unit, and the sensors are precisely pointed by a waterproof servo gear, thus eliminating errors at the hardware level.
This improves the reliability and accuracy of seabed electromagnetic detection data, avoids the accumulation of model errors caused by post-processing in traditional technologies, and ensures data quality.
Smart Images
Figure CN224067010U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of marine geological exploration instruments, specifically relating to a shallow-sea magnetotelluric data acquisition station that can autonomously correct its orientation. Background Technology
[0002] The statements herein provide only background information related to this invention and do not necessarily constitute prior art.
[0003] With the deepening of marine resource exploration and seabed geological research, the seabed electromagnetic detection technology system continues to innovate. Among them, seabed magnetotellurics, as a typical representative of passive source frequency domain electromagnetic sounding technology, relies on natural electromagnetic field sources to detect the electrical structure of the seabed strata by simultaneously acquiring the electric and magnetic field components of the seabed. This technology has three core advantages: First, it utilizes the Earth's natural electromagnetic field sources, eliminating the need for artificial transmission systems and significantly reducing equipment complexity and operating costs; second, it has strong adaptability and can maintain effective detection capabilities even under complex seabed topographic conditions; third, it has a wide detection depth range, capable of penetrating thousands of meters of seabed strata to obtain electrical parameters.
[0004] When implementing the aforementioned electromagnetic bathymetry technology, the precise orientation (north-south / east-west) of the horizontal components of the electric and magnetic fields is crucial for ensuring data quality. However, in actual operations, due to marine environmental factors such as ocean currents and deployment angle deviations, the electric and magnetic field sensors installed at the data acquisition station often experience azimuth shifts, leading to azimuth deviations in the observation data. This azimuth inaccuracy will cause interpretation errors in the electromagnetic field components. Existing technologies rely on the attitude information already collected by the acquisition device to perform magnetic field compensation during subsequent data processing to address the problem of data offset in the acquired electric and magnetic fields. However, this method has the drawback of requiring the establishment of complex electromagnetic field mathematical models. Real-world environmental conditions are highly complex; for example, interference factors such as temperature and material nonlinearity can cause model mismatch, amplifying errors at each compensation stage and potentially leading to erroneous results. In other words, existing methods primarily address the azimuth deviation problem at the software level, which increases the difficulty of subsequent data processing and affects the accuracy of seabed electrical structure detection results. Utility Model Content
[0005] To address the aforementioned problems and deficiencies in existing technologies, this invention provides a shallow-sea magnetotelluric data acquisition station capable of autonomously correcting its orientation. By setting up sensors such as MEMS inertial measurement units to detect the attitude of the acquisition station, the station autonomously adjusts the orientation of the electric and magnetic field sensors based on the detected attitude, thereby improving the reliability and accuracy of seabed electromagnetic detection data. This eliminates error sources at the hardware level and fundamentally avoids the problem of model error accumulation caused by post-processing data in traditional technologies through a physical mechanism.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A shallow-sea magnetotelluric data acquisition station capable of autonomously correcting its orientation includes a rectangular shell. The rectangular shell houses an orientation detection unit and an automatic correction unit. The orientation detection unit includes a MEMS inertial measurement unit, and the automatic correction unit includes a control chip, a drive circuit, and a waterproof servo gear mounted on the top of the rectangular shell. The MEMS inertial measurement unit is electrically connected to the control chip to transmit the acquired attitude signal to the control chip. The control chip is electrically connected to the drive circuit to transmit the generated control signal to the drive circuit. The drive circuit is electrically connected to the waterproof servo gear to drive the waterproof servo gear to rotate.
[0008] The top of the rectangular housing is equipped with a data acquisition unit, which includes an electromagnetic field sensor and an electric field sensor for acquiring magnetic field and electric field data. The electromagnetic field sensor and the electric field sensor are fixedly mounted on the top of the waterproof servo gear and rotate with the rotation of the waterproof servo gear.
[0009] A further technical solution is that the top of the waterproof servo gear is fixed with four electric field sensor connecting tubes that are perpendicular to each other. The four electric field sensor connecting tubes extend in four directions, and the four electric field sensors are respectively installed at the four extension positions of the electric field sensor connecting tubes to form an orthogonal measurement bridge. The four directions are the directions of the horizontal components of the two mutually perpendicular electric field signals.
[0010] In a further technical solution, the electric field sensor uses an electrode material with a small and stable polarization potential under high pressure on the seabed as the motor blank; the electrode material used is Ag or AgCl.
[0011] In a further technical solution, two mutually orthogonal magnetic field sensor connecting pipes are fixedly provided on the top of the waterproof servo gear. The two magnetic field sensor connecting pipes extend in the due east and due north directions respectively, and the two magnetic field sensors are respectively installed on the two magnetic field sensor connecting pipes.
[0012] In a further technical solution, the magnetic field sensor adopts a magnetic rod type magnetic field sensor.
[0013] A further technical solution involves coating the connection point between the magnetic field sensor connecting tube and the magnetic field sensor with epoxy resin adhesive.
[0014] In a further technical solution, the rectangular shell is integrally formed using PLA material, a gravity traction component is fixed at the bottom of the rectangular shell, and a lifting beam is provided at the top of the rectangular shell.
[0015] In a further technical solution, the gravity traction component is a concrete block.
[0016] In a further technical solution, a communication module is also provided inside the rectangular housing. The communication module is electrically connected to the control chip, and the electromagnetic field sensor and electric field sensor are electrically connected to the control chip. The communication module is used for data communication.
[0017] In a further technical solution, an energy supply module is also provided inside the rectangular shell. The energy supply module adopts a pressure-resistant high-capacity lithium battery pack. The energy supply module is electrically connected to the orientation detection unit, the automatic correction unit, the data acquisition unit, and the communication module, and is used to supply power to each unit.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] This invention provides a shallow-sea magnetotelluric data acquisition station capable of autonomously correcting its orientation. By setting up sensors such as MEMS inertial measurement units to detect the attitude of the data acquisition unit, the station determines the deflection relative to a set orientation based on the detected attitude. This allows the station to autonomously adjust the rotation of gears on top, which in turn drive the orientation of the electric and magnetic field sensors in the data acquisition unit, enabling the sensors to achieve precise pointing. This improves the reliability and accuracy of seabed electromagnetic detection data. This invention can eliminate error sources at the hardware level, fundamentally avoiding the model error accumulation problem caused by post-processing data in traditional technologies through a physical mechanism. Attached Figure Description
[0020] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.
[0021] Figure 1 This is a structural schematic diagram of the shallow sea magnetotelluric acquisition station that can autonomously correct its orientation in this utility model.
[0022] Figure 2 This is a schematic diagram of the connections between the various units in the electromagnetic acquisition station proposed in this utility model;
[0023] Figure 3 This is a circuit diagram of the driving circuit in this utility model;
[0024] Figure 4 This is the circuit diagram of the orientation detection unit of this utility model;
[0025] Figure 5 This is a circuit diagram of the data acquisition unit in this utility model;
[0026] Figure 6 This is the circuit diagram of the communication module in this utility model.
[0027] The components include: 1. Rectangular shell; 2. Orientation detection unit; 3. Automatic correction unit; 4. Data acquisition unit; 5. Communication module; 6. Energy supply module; 7. Gravity traction component; 8. Electric field sensor connecting pipe; 9. Magnetic field sensor connecting pipe; 10. Lifting beam; 11. Waterproof servo gear. Detailed Implementation
[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0030] like Figure 1 As shown, this utility model proposes a shallow-sea magnetotelluric data acquisition station with autonomous orientation correction, including a rectangular shell 1. The rectangular shell is integrally printed from PLA (polylactic acid) material. The top of the rectangular shell is equipped with a lifting beam 10, which facilitates the deployment of the acquisition station using a crane or similar device. The bottom of the rectangular shell is fixed with a gravity traction component 7, which can be made of a 60*60*10cm concrete block. By setting the gravity traction component at the bottom, the weight of the acquisition station can be increased, preventing the acquisition station from shifting position.
[0031] Furthermore, in this embodiment, the top of the rectangular shell 1 is provided with at least two lifting beams 10 to facilitate the deployment of the boom; preferably, the top of the rectangular shell 1 is provided with two lifting beams 10, and the two lifting beams 10 are symmetrically arranged at both ends of the top of the shell.
[0032] like Figure 2 As shown, the rectangular housing 1 houses an orientation detection unit 2 and an automatic correction unit 3. The orientation detection unit 2 includes a MEMS inertial measurement unit (IMU), and its circuitry is as follows: Figure 4As shown, the MEMS inertial measurement unit is connected to the control chip via an I2C bus. The MEMS inertial measurement unit synchronously acquires the three-axis acceleration, angular velocity, and magnetic field data from the data acquisition unit of the acquisition station and converts them into attitude signals. These attitude signals are then transmitted to the control chip of the automatic correction unit via a circuit. The attitude signal represents the overall attitude of the data acquisition unit. By detecting the attitude of this acquisition unit, the deflection of the acquisition station relative to a set orientation can be determined, providing data support for subsequent deflection correction.
[0033] The automatic correction unit 3 includes a control chip, a drive circuit, and a waterproof servo gear 11 mounted on the top of the rectangular housing. Preferably, this embodiment uses an STM38F104ZET6 chip as the control chip, which is used to control and correct the attitude of the magnetic field sensor and the electromagnetic field sensor. The MEMS inertial measurement unit (IMU) is electrically connected to the STM38F104ZET6 chip, transmitting the acquired attitude signals to it. The STM38F104ZET6 chip generates a control signal containing the gear rotation angle based on the received attitude signals and an existing control program. The STM38F104ZET6 chip is electrically connected to the drive circuit, which... Figure 3 As shown, the control chip transmits the generated control signal to the drive circuit, which is electrically connected to the waterproof servo gear. The control signal output from the output terminal of the drive circuit drives the servo gear to perform angle correction within the range of 0-180°.
[0034] Preferably, the control chip can also be equipped with a dual redundancy verification mechanism, which verifies the performance based on the latest acquired attitude data after each correction. If the standard is not met, a secondary fine-tuning is initiated. It should be noted that the above-mentioned control program for generating gear adjustment angles based on attitude signals and the secondary fine-tuning control program based on the dual redundancy verification mechanism are existing programs or algorithms in the field, and will not be described in detail here.
[0035] Furthermore, a data acquisition unit 4 is provided on the top of the rectangular housing 1, and the circuit of the data acquisition unit 4 is as follows: Figure 5 As shown, it includes an electromagnetic field sensor and an electric field sensor, used to collect magnetic field data and electric field data, respectively. Furthermore, the electromagnetic field sensor and electric field sensor are fixedly mounted on the top of the waterproof servo gear, rotating with the gear. By driving the gear to rotate, the electromagnetic field sensor and electric field sensor mounted on the gear can reach the set orientation, correcting their orientation deflection and ensuring the accuracy of subsequent data acquisition.
[0036] The electromagnetic field sensor is used to collect electromagnetic data. This sensor uses electrode materials with small and stable polarization potential under high-pressure conditions on the seabed as the motor blank, such as Ag or AgCl electrode materials. Four mutually perpendicular electric field sensor connecting pipes 8 are fixed to the top of the waterproof servo gear. Each connecting pipe is a 4m long PC tube, extending in four directions. Four electric field sensors are installed at the four extended positions of the connecting pipes, forming an orthogonal measurement bridge for the x and y axes. These four directions correspond to the directions of the horizontal components of the two mutually perpendicular electric field signals Ex and Ey. Each acquisition station can collect two mutually perpendicular electric field signals, Ex and Ey.
[0037] The magnetic field sensor is an inductive sensor. This data acquisition station only measures the horizontal component of the magnetic field. The magnetic field sensor is a magnetic rod type. Two mutually orthogonal magnetic field sensor connecting tubes 9 are fixed on the top of the waterproof servo gear. The two magnetic field sensor connecting tubes extend in the due east and due north directions respectively, and the two magnetic rod type magnetic field sensors (magnetic rods are 4m long) are respectively installed on the two magnetic field sensor connecting tubes. Preferably, epoxy resin is applied to the connection between the magnetic field sensor connecting tube and the magnetic field sensor to ensure waterproofing.
[0038] In addition, a communication module 5 is also provided inside the rectangular housing 1. The circuit of this communication module is as follows: Figure 6 As shown, it supports current data transmission. Specifically, the aforementioned electromagnetic field sensor and electric field sensor are electrically connected to the control chip via cables to transmit the collected electromagnetic field data to the control chip; the control chip is electrically connected to the communication module, which communicates with the ground monitoring center to transmit the collected data to the ground monitoring center in real time.
[0039] Preferably, the rectangular housing also houses an energy supply module 6, which is electrically connected to the orientation detection unit, automatic correction unit, data acquisition unit, and communication module to supply power to each unit. The energy supply module uses a high-capacity, pressure-resistant lithium battery pack to ensure stable power supply over a long period of time.
[0040] The specific working process of this utility model is as follows:
[0041] The data collection station deployment phase involves first installing four electric field sensors corresponding to the horizontal components of Ex and Ey at the four extended positions of the electric field sensor connecting pipe 8, forming an orthogonal measurement bridge; simultaneously, a 4m magnetic rod-type magnetic field sensor is installed on the magnetic field sensor connecting pipe 9. After the above assembly is completed, equipment debugging is performed. After ensuring that all equipment is operating normally, the system is navigated to the designated data collection station deployment point. After being securely connected to the boom and lifting beam 10, the data collection station is slowly lowered into the seawater, ensuring that the equipment touches the bottom vertically.
[0042] The autonomous orientation correction stage is as follows: After the data acquisition station enters the water, the MEMS inertial measurement unit in the orientation detection unit 2 collects triaxial acceleration, angular velocity, and magnetic field data. This data is used to detect and obtain the attitude data of the data acquisition unit and transmit it to the automatic correction unit. When the controller of the STM38F104ZET6 chip in the automatic correction unit 3 receives the attitude signal, it performs correction judgment and generates a PWM control signal to drive the waterproof servo gear 11 to perform angle calibration. After the drive unit drives the waterproof servo gear 11 to rotate by a specified angle, the autonomous orientation correction of the data acquisition station is completed. The aforementioned correction judgment is as follows: if the preset azimuth deviation threshold is horizontal azimuth error < 3°, the correction mechanism is triggered when the detected data exceeds this threshold. After each correction, the controller immediately restarts the MEMS inertial measurement unit for a secondary attitude measurement. If the residual deviation > 0.5°, the fine-tuning mode is activated: the servo switches to a 0.1° step accuracy for fine-tuning, forming a closed loop. If three consecutive calibrations fail to reach the set threshold, the controller determines that the calibration is abnormal. The controller and communication module 5 send a GPS coordinate alarm to the ground receiver, prompting the operator to retrieve and repair the device, thus preventing subsequent data acquisition errors from causing significant errors in the exploration results. It should be noted that the aforementioned azimuth correction judgment and correction control methods are all existing control methods, implemented by importing existing programs into the controller, and will not be elaborated further here.
[0043] Data acquisition phase. After the above autonomous calibration is completed, synchronous measurement of electric and magnetic fields is initiated. The corresponding magnetic and electric field data are collected by electromagnetic field sensors and electric field sensors. The data is then transmitted back to the marine receiver in real time via communication module 5 and stored locally for subsequent data processing and analysis.
[0044] This invention utilizes a multi-sensor detection system to monitor the attitude of the data acquisition station. Based on this attitude, it autonomously adjusts and corrects the orientation of the electromagnetic and electric field sensors within the acquisition unit. This ensures that the sensors are accurately aligned north-south and east-west, improving the accuracy of electromagnetic data acquisition and avoiding subsequent cumbersome data correction calculations. It overcomes the technical limitation of traditional underwater data acquisition stations that cannot correct orientation. This invention not only effectively overcomes the orientation deviation problem caused by marine environmental disturbances but also significantly improves the reliability and geological interpretation accuracy of seabed electromagnetic detection data through an automated calibration mechanism, providing new technical equipment support for resource exploration in shallow sea areas.
[0045] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.
Claims
1. A shallow sea magnetotelluric acquisition station capable of self-orienting, characterized in that, The application relates to a rectangular shell, which is internally provided with an azimuth detection unit and an automatic correction unit; the azimuth detection unit comprises a MEMS inertial measurement unit; the automatic correction unit comprises a control chip, a driving circuit and a waterproof steering gear arranged on the top of the rectangular shell; the MEMS inertial measurement unit is electrically connected to the control chip and used for transmitting collected attitude signals to the control chip; the control chip is electrically connected to the driving circuit and used for transmitting generated control signals to the driving circuit; and the driving circuit is electrically connected to the waterproof steering gear to drive the waterproof steering gear to rotate. The top of the rectangular shell is provided with a data acquisition unit, which comprises an electromagnetic field sensor and an electric field sensor used for collecting magnetic field and electric field data; the electromagnetic field sensor and the electric field sensor are fixedly arranged on the top of the waterproof steering gear and rotate with the waterproof steering gear.
2. The shallow sea magnetotelluric acquisition station capable of self- correcting orientation of claim 1, wherein, The top of the waterproof steering gear is fixedly provided with four electric field sensor connecting pipes which are perpendicular to each other, the four electric field sensor connecting pipes extend in four directions, four electric field sensors are respectively arranged in the four extending directions of the electric field sensor connecting pipes to form a quadrature bridge, and the four directions are the directions of two-way perpendicular electric field signal horizontal components.
3. The shallow sea magnetotelluric acquisition station capable of self- correcting orientation of claim 2, wherein, The electric field sensor adopts an electrode material with small and stable polarization potential in a high-pressure environment of the seabed as a motor embryo body; the electrode material is Ag or AgCl.
4. The shallow sea magnetotelluric acquisition station capable of self- correcting orientation of claim 1, wherein, The top of the waterproof steering gear is fixedly provided with two magnetic field sensor connecting pipes which are perpendicular to each other, the two magnetic field sensor connecting pipes respectively extend in the east and north directions, and two magnetic field sensors are respectively arranged on the two magnetic field sensor connecting pipes.
5. The shallow sea MT acquisition station capable of self-correcting orientation according to claim 4, characterized in that, The magnetic field sensor adopts a magnetic bar type magnetic field sensor.
6. The shallow sea MT acquisition station capable of self-correcting orientation according to claim 4, characterized in that, The magnetic field sensor connecting pipe and the magnetic field sensor are connected by epoxy resin glue.
7. The shallow sea MT acquisition station capable of self-orienting according to claim 1, wherein, The rectangular shell is integrally prepared by using PLA material, the bottom of the rectangular shell is fixedly provided with a gravity traction member, and the top of the rectangular shell is provided with a lifting beam.
8. The shallow sea MT acquisition station capable of self-correcting orientation according to claim 7, characterized in that, The gravity traction member is a concrete block.
9. The self-orienting shallow marine magnetotelluric station of claim 1, wherein, The rectangular shell is internally provided with a communication module, the communication module is electrically connected to the control chip, the electromagnetic field sensor and the electric field sensor are electrically connected to the control chip, and the communication module is used for data communication.
10. The shallow sea MT acquisition station capable of self-correcting orientation according to claim 9, characterized in that, The rectangular shell is internally provided with an energy supply module, the energy supply module adopts a compression-resistant high-capacity lithium battery pack, and the energy supply module is electrically connected to the azimuth detection unit, the automatic correction unit, the data acquisition unit and the communication module to supply power to the units.