Underwater calibration method, device, and computer-readable storage medium

Abstract

The application discloses an underwater calibration method, device and computer readable storage medium. The underwater calibration method comprises the following steps: in response to a calibration instruction, confirming a first calibration posture of an underwater device; controlling the underwater device to perform at least one week of fixed-point horizontal rotation and collect first magnetometer data; after the first magnetometer data collection is completed, adjusting the posture of the underwater device to a second calibration posture; controlling the underwater device to perform at least one week of fixed-point horizontal rotation and collect second magnetometer data in the second calibration posture; and calibrating the magnetometer according to the first magnetometer data and the second magnetometer data. Compared with the prior art, the underwater magnetometer calibration can be realized, and after calibration, the underwater device can work in the same environment, the disturbance caused by environmental change and the electromagnetic of the underwater device itself is reduced, and the navigation precision is improved.

Description

Technical Field

[0001] This invention relates to the field of marine observation technology, and more particularly to an underwater calibration method, device, and computer-readable storage medium. Background Technology

[0002] Before deploying underwater equipment or when the operating environment changes, magnetometers typically need to be calibrated. Calibrating magnetometers helps eliminate inherent sensor errors, compensate for magnetic interference from the underwater equipment itself, such as the deviation of fixed magnetic fields generated by motors and magnetic tools, and improve the accuracy of heading measurements.

[0003] Traditional methods of calibrating magnetometers are often carried out in a shore environment. The method of calibrating the magnetometer separately and then assembling it into the underwater equipment inevitably results in the magnetic interference of the underwater equipment itself. The method of calibrating the entire underwater equipment as a whole is time-consuming, labor-intensive, and poses safety risks due to the large weight of the underwater equipment. It also places high demands on the calibration environment. Summary of the Invention

[0004] The main objective of this invention is to provide an underwater calibration method, device, and computer-readable storage medium, aiming to solve the problem in the prior art that underwater devices cannot eliminate disturbances caused by environmental changes and the electromagnetic fields of the underwater devices themselves, resulting in poor calibration results.

[0005] To address the aforementioned technical problems, this application proposes an underwater calibration method for calibrating a magnetometer within an underwater device in an underwater environment. The underwater calibration method includes:

[0006] In response to the calibration command, confirm the first calibration attitude of the underwater device;

[0007] Control the underwater device to perform at least one fixed-point horizontal rotation and collect data from the first magnetometer;

[0008] After completing the first magnetometer data acquisition, the attitude of the underwater device is adjusted to the second calibration attitude;

[0009] In the second calibration attitude, the underwater device is controlled to perform at least one fixed-point horizontal rotation and acquire second magnetometer data;

[0010] The magnetometer is calibrated based on the first magnetometer data and the second magnetometer data.

[0011] Optionally, the step of adjusting the attitude of the underwater device to the second calibration attitude after completing the first magnetometer data acquisition includes:

[0012] After completing the data acquisition from the first magnetometer, control the underwater device to remain hovering;

[0013] Confirm the third calibration attitude of the underwater equipment;

[0014] Based on the orientation of the underwater device in the third calibration posture, the attitude of the underwater device is adjusted to the second calibration posture; the third calibration posture and the second calibration posture are perpendicular to each other; in the second calibration posture or the third calibration posture, the underwater device faces the bottom surface; the position of the geometric center of the underwater device remains unchanged during the attitude adjustment process.

[0015] Optionally, during the adjustment process from the third calibration attitude to the second calibration attitude, the underwater device ensures that the position of the geometric center of the underwater device remains unchanged based on real-time detection data of the downward DVL and forward DVL.

[0016] Optionally, the third calibration posture is the same as the first calibration posture.

[0017] Optionally, the step of controlling the underwater device to perform at least one full horizontal rotation at a fixed point and collecting data from the first magnetometer includes:

[0018] Control the underwater equipment to rotate in a single direction at a set speed to a fixed point.

[0019] During the rotation, sensed magnetic field data is continuously acquired; the magnetic field data includes at least the magnetic field direction and magnetic field strength.

[0020] After the cumulative rotation angle exceeds one revolution, the magnetic field data is recorded and the first magnetometer data is generated.

[0021] Optionally, the step of controlling the underwater device to perform at least one full horizontal rotation at a fixed point and collecting data from the first magnetometer includes:

[0022] The underwater device is controlled to rotate horizontally at a fixed point in the first direction at a set rotation speed for at least one revolution and to collect data from the third magnetometer.

[0023] The underwater device is controlled to rotate horizontally at a fixed point in the second direction at the set rotation speed for at least one revolution and to collect data from the fourth magnetometer.

[0024] The first magnetometer data is generated based on the third magnetometer data and the fourth magnetometer data;

[0025] The first direction and the second direction provide different directions of rotation.

[0026] Optionally, the rotation angle of the underwater device during the fixed-point horizontal rotation can be measured and accumulated in real time using a gyroscope.

[0027] Optionally, the step of calibrating the magnetometer based on the first magnetometer data and the second magnetometer data includes:

[0028] An anti-interference compensation model is established to remove electromagnetic interference generated by the underwater equipment itself.

[0029] The first magnetometer data and the second magnetometer data are processed according to the anti-interference compensation model to obtain the fifth magnetometer data and the sixth magnetometer data;

[0030] The fifth and sixth magnetometer data are calibrated by applying an ellipsoid fitting algorithm.

[0031] To address the aforementioned technical problems, the present invention also proposes an underwater device, comprising: a memory, a processor, and a control program for the underwater device stored in the memory and executable on the processor, wherein the control program for the underwater device is configured to implement the steps of the underwater calibration method described above.

[0032] To address the aforementioned technical problems, the present invention also provides a computer-readable storage medium storing a control program for an underwater device, wherein the control program for the underwater device, when executed by a processor, implements the steps of the underwater calibration method described above.

[0033] Compared with existing technologies, the underwater calibration method provided by this invention enables the calibration process to be automatically realized in the underwater environment, allowing for the calibration of magnetometers in the underwater environment. After calibration, the system can operate in the same environment, reducing disturbances caused by environmental changes and the electromagnetic interference of the underwater equipment itself, thereby improving navigation accuracy. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] in:

[0036] Figure 1 This is a flowchart illustrating an embodiment of the underwater calibration method provided in this application;

[0037] Figure 2 This is a front view of the underwater equipment provided in this application in a horizontal position;

[0038] Figure 3 This is a top view of the underwater equipment provided in this application, showing a fixed-point horizontal rotation in a horizontal posture.

[0039] Figure 4 yes Figure 1 The diagram shows a detailed flowchart of an embodiment of the underwater calibration method step S12.

[0040] Figure 5 yes Figure 1 A schematic diagram of a specific process for another embodiment of the underwater calibration method step S12 shown;

[0041] Figure 6 yes Figure 1 The diagram shows a detailed flowchart of an embodiment of the underwater calibration method step S13.

[0042] Figure 7 This is a schematic diagram of a scenario for calibrating the attitude of underwater equipment provided in this application;

[0043] Figure 8 This is a schematic diagram of a scenario where the downward multibeam sonar reflected signal of the underwater equipment provided in this application returns an invalid beam;

[0044] Figure 9 This is a top view of the underwater equipment provided in this application, showing a fixed-point horizontal rotation in a vertical orientation.

[0045] Figure 10 yes Figure 1 The diagram shows a detailed flowchart of an embodiment of the underwater calibration method step S15.

[0046] Figure 11 This is a schematic diagram of an embodiment of the underwater device provided in this application. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0049] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0050] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0051] In this application, the term "exemplary" is used to mean "serving as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other embodiments, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0052] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0053] Please see Figure 1 , Figure 1This is a flowchart illustrating an embodiment of the underwater calibration method provided in this application. The method can be applied to underwater equipment equipped with at least a forward Doppler Velocity Log (DVL), a downward Doppler Velocity Log (DVL), and a depth sensor. This enables the underwater equipment to detect multiple parameters such as speed, distance, and depth. The underwater equipment also includes a camera device to provide comprehensive visual observation for the user. In a preferred embodiment, the forward DVL can be understood as the DVL device being fixedly mounted on the underwater equipment and aligned with the camera device; or the DVL device being movably mounted on the underwater equipment via an auxiliary device (such as a gimbal, bracket, etc.), and after angle adjustment, aligned with the camera device. The underwater equipment includes, but is not limited to, underwater robots such as remotely operated vehicles (ROVs) and autonomous remote-controlled vehicles (ARVs), and may also be underwater detection equipment, underwater submarine equipment or other underwater operation equipment. This application does not limit this.

[0054] The underwater device is also equipped with a magnetometer to detect magnetic field information in the environment (such as the Earth's magnetic field or artificial magnetic field) and convert it into electrical signals for processing by the underwater device's control system.

[0055] The underwater calibration method provided in this embodiment includes the following steps:

[0056] like Figure 1 As shown, the specific steps are as follows:

[0057] Step S11: Respond to the calibration command and confirm the first calibration attitude of the underwater equipment.

[0058] In this embodiment, the underwater equipment is placed in an underwater environment beforehand to calibrate the magnetometer. After calibration, operations can proceed directly, reducing disturbances caused by environmental changes and the electromagnetic interference of the underwater equipment itself, thus improving navigation accuracy. Calibrating the magnetometer underwater offers certain advantages, helping to eliminate environmental interference and improve data accuracy.

[0059] Specifically, after being placed in the underwater environment, the underwater equipment maintains a fixed hover position within the environment through its own control, awaiting calibration instructions. In situations where there is water flow in the underwater environment, it also needs to resist the current while hovering in place to avoid drifting caused by water flow impact.

[0060] Preferably, the first calibration attitude is a horizontal attitude; that is, after receiving the calibration command, the underwater device can adjust its attitude to a horizontal attitude through the built-in inertial measurement unit, or it can adjust its attitude to a horizontal attitude through other methods such as visual-assisted verification or multi-sensor-assisted verification. This application does not limit the adjustment method.

[0061] Please see Figure 2 , Figure 2 This is a front view of the underwater equipment provided in this application in a horizontal orientation. Figure 2 In a horizontal orientation scenario, the underwater equipment emits multibeam sonar signals towards the seabed via downward DVL (Directional Volume Lift), determines its speed relative to the seabed based on the sonar reflection signals, and then ensures that the underwater equipment remains at a fixed position by controlling the thrusters for compensation.

[0062] Step S12: Control the underwater equipment to perform at least one full horizontal rotation at a fixed point and collect the first magnetometer data.

[0063] In this embodiment of the application, the underwater device activates the calibration function of the magnetometer, that is, controls the magnetometer to start collecting magnetic field data.

[0064] It is understood that when the underwater device initiates the magnetometer calibration function, it will perform at least one full horizontal rotation at a fixed point in the first calibration posture. This fixed point can be understood as controlling the underwater device to rotate horizontally while keeping its geometric center position unchanged. In this application, the geometric center is the center point of the three-dimensional geometry of the underwater device's physical structure. Please refer to [link / reference] for details. Figure 3 , Figure 3 This is a top view of the underwater equipment provided in this application, showing its horizontal rotation at a fixed point in a horizontal posture.

[0065] Please refer to details. Figure 4 , Figure 4 yes Figure 1 The diagram shows a detailed flowchart of an embodiment of the underwater calibration method step S12.

[0066] like Figure 4 As shown, the specific steps are as follows:

[0067] Step S21: Control the underwater equipment to rotate in a single direction at a set speed to a fixed point.

[0068] In this embodiment, the gyroscope built into the underwater device can output and detect the device's Roll, Pitch, and Yaw movements. During the horizontal rotation of the underwater device, the gyroscope can measure the angular velocity of the device's motion in real time, thus providing a reference for the rotation angle of the underwater device.

[0069] During the calibration of the magnetometer, the rotation speed of the underwater equipment should not be too fast and should be controlled within a certain speed range, such as 5 degrees / second, 15 degrees / second, 20 degrees / second, 30 degrees / second, etc.

[0070] Step S22: Continuously acquire the sensed magnetic field data during the rotation process.

[0071] In this embodiment, during the underwater device's fixed-point horizontal rotation in either a counter-clockwise or clockwise direction, the angle of rotation relative to the first calibration posture can be accumulated using a gyroscope. Once the accumulated angle reaches 360 degrees, it is confirmed that one full rotation has been completed, and the process proceeds to the next step, S23. Through step S22, the magnetic field strength in different directions can be obtained within the plane.

[0072] Step S23: After the cumulative rotation angle exceeds one revolution, the magnetic field data is recorded and the first magnetometer data is generated.

[0073] In this embodiment of the application, in order to improve the stability of the underwater equipment, the underwater equipment can be controlled to enter a hovering state after rotating one revolution. The attitude of the underwater equipment can also be detected to confirm whether it is maintained in the first calibration attitude.

[0074] Understandably, the more rotations, the more comprehensive the data obtained. When there are multiple clockwise or counterclockwise rotations, the third or fourth magnetometer data can be represented as a collection of multiple single-rotation data sets. Furthermore, the first magnetometer data is a collection including the third and fourth magnetometer data, and in terms of magnetic field data, it includes at least the magnetic field direction and the corresponding magnetic field strength.

[0075] When an underwater device is performing a fixed-point horizontal rotation in a horizontal posture, the downward DVL configured on the underwater device can maintain the fixed-point position, thereby maintaining the stability of the underwater device during the rotation process and ensuring the accuracy of the magnetometer data acquisition.

[0076] Downward-facing DVL can transmit multibeam sonar signals toward the seabed or underground and obtain the velocity of underwater equipment relative to the seabed or underground in real time based on the reflected signals, thereby calculating the position information of the underwater equipment.

[0077] Once the underwater equipment confirms its first calibration attitude, it can determine its initial position by reflecting the multibeam sonar signal emitted downwards by the DVL (Diverterless Vehicle). During the stationary horizontal rotation, the underwater equipment compares its real-time position with its initial position to determine if any positional deviation has occurred. If a positional deviation occurs, the underwater equipment adjusts its position back to the initial position according to the deviation between the real-time and initial positions.

[0078] In this embodiment, the underwater device adjusts its position to the initial position based on the offset direction and offset value between the real-time position and the initial position.

[0079] Specifically, the underwater equipment uses the downward DVL data to adjust the output force of the thruster to achieve the positioning function, that is, the thruster output is decomposed into rotational torque (controlling the yaw angle) and anti-drift force (counteracting lateral displacement).

[0080] To achieve better results and avoid tangling, the underwater equipment should be rotated horizontally at least twice in a fixed position. The direction of rotation should be different for each two consecutive cycles, such as first counterclockwise and then clockwise, or first clockwise and then counterclockwise.

[0081] Please refer to details. Figure 5 , Figure 5 yes Figure 1 The diagram shows a detailed flow chart of another embodiment of the underwater calibration method step S12.

[0082] like Figure 5 As shown, the specific steps are as follows:

[0083] Step S31: Control the underwater equipment to rotate horizontally at a fixed point in the first direction at a set rotation speed for at least one revolution and collect data from the third magnetometer.

[0084] Step S32: Control the underwater equipment to rotate horizontally at a fixed point in the second direction at a set rotation speed for at least one revolution and collect data from the fourth magnetometer.

[0085] Step S33: Generate first magnetometer data based on the third magnetometer data and the fourth magnetometer data.

[0086] The first direction and the second direction provide different directions of rotation. For example, the first direction is clockwise rotation and the second direction is counterclockwise rotation; or the first direction is counterclockwise rotation and the second direction is clockwise rotation.

[0087] Step S13: After completing the first magnetometer data acquisition, adjust the attitude of the underwater equipment to the second calibration attitude.

[0088] In this embodiment of the application, after the first magnetometer data acquisition is completed, it is necessary to continue to acquire the second magnetometer data in another direction. Therefore, it is necessary to adjust the attitude of the underwater device to the second calibration attitude, which is the initial attitude for acquiring the second magnetometer data.

[0089] Please refer to details. Figure 6 , Figure 6 yes Figure 1 The diagram shows a detailed flowchart of an embodiment of the underwater calibration method step S13.

[0090] like Figure 6 As shown, the specific steps are as follows:

[0091] Step S41: After completing the first magnetometer data acquisition, control the underwater equipment to keep it hovering.

[0092] Step S42: Confirm the third calibration attitude of the underwater equipment.

[0093] In this embodiment of the application, after completing the data acquisition of the magnetometer during the fixed-point horizontal rotation, the current attitude of the underwater device is recorded as the third calibration attitude.

[0094] It should be noted that the first and third calibration attitudes can be the same or different. In the same scenario, where the underwater device stops rotating after completing one full rotation, the first and third calibration attitudes are the same with the assistance of the positioning function. In different scenarios, such as when the underwater device can rotate an additional angle after completing one full rotation to collect extra magnetometer data to supplement or correct the previous magnetometer data, the heading angle of the third calibration attitude will differ from that of the first calibration attitude.

[0095] Step S43: Based on the orientation of the underwater equipment in the third calibration attitude, adjust the attitude of the underwater equipment to the second calibration attitude; the third calibration attitude and the second calibration attitude are perpendicular to each other; in the second calibration attitude or the third calibration attitude, the underwater equipment faces the bottom surface; the position of the geometric center of the underwater equipment remains unchanged during the attitude adjustment process.

[0096] In this embodiment, the first calibration attitude is horizontal, and the second calibration attitude is vertical. The underwater device is tilted around a horizontal axis (such as the X-axis or Y-axis), gradually tilting from a horizontal position to a vertical one. In a preferred embodiment, the second calibration attitude is adjusted by tilting the front end of the underwater device downwards. Furthermore, the geometric center of the underwater device remains unchanged during the adjustment from the first calibration attitude to the second calibration attitude. Please refer to [link to specific details] for further information. Figure 7 , Figure 7 This is a schematic diagram of the underwater equipment calibration attitude adjustment scenario provided in this application.

[0097] In other embodiments, the first calibration attitude is the vertical attitude of the underwater device facing the bottom surface, and the second calibration attitude is the horizontal attitude.

[0098] Furthermore, in such Figure 7 The calibration attitude adjustment process shown requires the combined use of forward DVL and downward DVL.

[0099] Specifically, during attitude adjustment, some beams in the multibeam sonar signal emitted by the downward DVL will become ineffective beams at a certain moment. At this time, the forward DVL will be used to complete the fixed-point control of the ROV.

[0100] To detect a failed beam, underwater equipment can check the validity of the distance information returned by the downward multibeam sonar reflection signal. If it is invalid, the beam is confirmed as invalid. Invalid beams occur when: the downward multibeam sonar reflection signal cannot detect the seabed or subsurface, in which case the distance information is infinite; or the downward multibeam sonar reflection signal detects a sudden increase in the distance from the underwater equipment to the seabed or subsurface, which may indicate a change in terrain, and can also be considered a scenario of an invalid beam.

[0101] Please refer to details. Figure 8 , Figure 8 This is a schematic diagram of a scenario where the downward multibeam sonar reflected signal of the underwater device provided in this application feeds back an invalid beam.

[0102] When the number of invalid beams directed to DVL exceeds a certain amount, i.e. Figure 8 This scenario indicates that the pitch angle of the underwater equipment has been adjusted, allowing it to be located using the reflected signals from the multi-beam sonar emitted by the forward DVL. At this point, the multi-beam sonar signal emitted by the forward DVL gradually deflects towards the seabed or subsurface, effectively compensating for the ineffective beams generated by the downward DVL.

[0103] Overall, underwater equipment can achieve accurate positioning during attitude adjustment from horizontal to vertical by combining downward DVL and forward DVL.

[0104] Step S14: Under the second calibration attitude, control the underwater equipment to perform at least one fixed-point horizontal rotation and collect data from the second magnetometer.

[0105] In this embodiment, the underwater device rotates horizontally at a fixed point in a vertical orientation and collects magnetometer data. The implementation process is basically the same as that of step S12, the main difference being that in this step, the underwater device uses forward DVL-assisted positioning for positioning. Please refer to [link to details]. Figure 9 , Figure 9This is a top view of the underwater equipment provided in this application, showing its vertical orientation and horizontal rotation at a fixed point.

[0106] Step S15: Calibrate the magnetometer based on the data from the first magnetometer and the second magnetometer.

[0107] In this embodiment of the application, the collected first magnetometer data and second magnetometer data will be used to calibrate the magnetometer using an ellipsoid fitting algorithm.

[0108] Please refer to details. Figure 10 , Figure 10 yes Figure 1 The diagram shows a detailed flowchart of an embodiment of the underwater calibration method step S15.

[0109] like Figure 9 As shown, the specific steps are as follows:

[0110] Step S51: Establish an anti-interference compensation model to remove electromagnetic interference generated by the underwater equipment itself.

[0111] Specifically, since the thruster also generates some disturbing magnetic fields during operation, it is necessary to establish this interference compensation model based on the relationship between the thruster current and the magnetic field to remove the electromagnetic interference generated by the thruster.

[0112] Step S52: Process the first magnetometer data and the second magnetometer data according to the anti-interference compensation model to obtain the fifth magnetometer data and the sixth magnetometer data.

[0113] Step S53: The data from the fifth and sixth magnetometers are calibrated using an ellipsoid fitting algorithm.

[0114] The fifth magnetometer data is the first magnetometer data after interference removal, and the sixth magnetometer data is the second magnetometer data after interference removal. Ellipsoid fitting is a mathematical method used to fit a set of three-dimensional data points into an ellipsoidal shape. In magnetometer calibration, uncalibrated data often forms an ellipsoidal distribution due to various interferences, while calibrated data should form a sphere centered at the origin. The purpose of using the ellipsoid fitting algorithm is to estimate error parameters, that is, to map the fifth and sixth magnetometer data onto an ideal sphere to eliminate errors and achieve magnetometer calibration.

[0115] Compared with existing technologies, the underwater calibration method provided by this invention enables the calibration process to be automatically realized in the underwater environment, allowing for the calibration of magnetometers in the underwater environment. After calibration, the system can operate in the same environment, reducing disturbances caused by environmental changes and the electromagnetic interference of the underwater equipment itself, thereby improving navigation accuracy.

[0116] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0117] Reference Figure 11 The diagram below provides a structural schematic of the underwater device for an embodiment of this application.

[0118] The underwater device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk drive. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0119] Those skilled in the art will understand that Figure 11 The structure shown does not constitute a limitation on the underwater equipment and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0120] like Figure 11 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a control program for underwater equipment.

[0121] exist Figure 11 In the underwater device shown, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the underwater device of the present invention can be set in the underwater device. The underwater device calls the control program of the underwater device stored in the memory 1005 through the processor 1001 and executes the above-mentioned underwater calibration method.

[0122] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0123] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0124] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0125] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An underwater calibration method, characterized in that, The underwater calibration method is used to calibrate a magnetometer in an underwater device in an underwater environment, and the underwater calibration method includes: In response to the calibration command, confirm the first calibration attitude of the underwater device; Control the underwater device to perform at least one fixed-point horizontal rotation and collect data from the first magnetometer; After completing the first magnetometer data acquisition, the attitude of the underwater device is adjusted to the second calibration attitude; In the second calibration attitude, the underwater device is controlled to perform at least one fixed-point horizontal rotation and acquire data from the second magnetometer. The magnetometer is calibrated based on the first magnetometer data and the second magnetometer data.

2. The underwater calibration method for a magnetometer according to claim 1, characterized in that, The step of adjusting the attitude of the underwater device to the second calibration attitude after completing the first magnetometer data acquisition includes: After completing the data acquisition from the first magnetometer, control the underwater device to remain hovering; Confirm the third calibration attitude of the underwater equipment; Based on the orientation of the underwater device in the third calibration posture, the attitude of the underwater device is adjusted to the second calibration posture; the third calibration posture and the second calibration posture are perpendicular to each other; in the second calibration posture or the third calibration posture, the underwater device faces the bottom surface; the position of the geometric center of the underwater device remains unchanged during the attitude adjustment process.

3. The underwater calibration method according to claim 2, characterized in that, During the adjustment process from the third calibration attitude to the second calibration attitude, the underwater device ensures that the position of the geometric center of the underwater device remains unchanged based on the real-time detection data of the downward DVL and forward DVL.

4. The underwater calibration method according to claim 2, characterized in that, The third calibration posture is the same as the first calibration posture.

5. The underwater calibration method according to claim 1, characterized in that, The step of controlling the underwater device to perform at least one full horizontal rotation at a fixed point and collecting data from the first magnetometer includes: Control the underwater equipment to rotate in a single direction at a set speed to a fixed point. During the rotation, sensed magnetic field data is continuously acquired; the magnetic field data includes at least the magnetic field direction and magnetic field strength. After the cumulative rotation angle exceeds one revolution, the magnetic field data is recorded and the first magnetometer data is generated.

6. The underwater calibration method for a magnetometer according to claim 1, characterized in that, The step of controlling the underwater device to perform at least one full horizontal rotation at a fixed point and collecting data from the first magnetometer includes: The underwater device is controlled to rotate horizontally at a fixed point in the first direction at a set rotation speed for at least one revolution and to collect data from the third magnetometer. The underwater device is controlled to rotate horizontally at a fixed point in the second direction at the set rotation speed for at least one revolution and to collect data from the fourth magnetometer. The first magnetometer data is generated based on the third magnetometer data and the fourth magnetometer data; The first direction and the second direction provide different directions of rotation.

7. The underwater calibration method according to claim 5 or 6, characterized in that, The rotation angle of the underwater device during the fixed-point horizontal rotation is measured and accumulated in real time using a gyroscope.

8. The underwater calibration method for a magnetometer according to claim 1, characterized in that, The step of calibrating the magnetometer based on the first magnetometer data and the second magnetometer data includes: An anti-interference compensation model is established to remove electromagnetic interference generated by the underwater equipment itself. The first magnetometer data and the second magnetometer data are processed according to the anti-interference compensation model to obtain the fifth magnetometer data and the sixth magnetometer data; The fifth and sixth magnetometer data are calibrated by applying an ellipsoid fitting algorithm.

9. An underwater device, characterized in that, The underwater device includes: a memory, a processor, and a control program for the underwater device stored in the memory and executable on the processor, the control program being configured to implement the steps of the underwater calibration method as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a control program for an underwater device, which, when executed by a processor, implements the steps of the underwater calibration method as described in any one of claims 1 to 8.

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