Method for keeping position of water area carrier based on single propeller and related equipment

Abstract

A method, medium, thruster (10) and water area mobile device (100) for implementing position holding of a water area carrier (20) based on a single thruster, the method comprising: (S11) in response to a position holding instruction, taking the current position of the water area carrier (20) as a target position; (S12) target thrust required by the propeller (10) is calculated, and the target thrust is used for enabling the bow or the stern of the water area carrier (20) to face the target position and enabling the water area carrier (20) to advance or retreat so as to keep the water area carrier (20) at the target position; and (S13) controlling the propeller (10) to generate target thrust. The position of the water area carrier (20) can be automatically kept based on the single propeller (10), so that when the water area carrier (20) is provided with only one propeller (10), the position of the water area movable equipment (100) can be automatically kept.

Description

Technical Field

[0001] The present application relates to the field of intelligent driving technology, and in particular to a method and related equipment for maintaining the position of a water vehicle based on a single thruster. Background Art

[0002] The position keeping function is intended to lock the position of the water body at a specific position. In the related art, the water body has an automatic position keeping function without manual operation by the user. However, the above automatic position keeping function requires the use of two propellers to achieve automatic position keeping, and the automatic position keeping cannot be achieved with a single propeller. Summary of the invention

[0003] In a first aspect, the present application provides a method for achieving position maintenance of a water vehicle based on a single thruster, the method comprising: in response to a position maintenance instruction, taking the current position of the water vehicle as a target position; calculating the target thrust required by the thruster, the target thrust being used to make the bow or stern of the water vehicle face the target position, and to make the water vehicle move forward or backward to maintain the target position; and controlling the thruster to generate the target thrust.

[0004] In a second aspect, the present application provides a method for maintaining the position of a water body carrier based on a single thruster, the method comprising: in response to a position maintaining instruction, taking the current position of the water body carrier as the target position; obtaining a subsequent position of the water body carrier; calculating an angular error between the subsequent position and the target position; determining a thrust direction of a target thrust required by the thruster based on the angular error; and controlling the thruster to generate the target thrust in the thrust direction so as to maintain the water body carrier at the target position.

[0005] In a third aspect, the present application provides a computer-readable storage medium having computer instructions stored thereon, and when the computer instructions are executed by a processor, the method described in the first aspect or the second aspect of the present application is implemented.

[0006] In a fourth aspect, the present application provides a thruster, comprising a propulsion device and a processor, wherein the processor is electrically connected to the propulsion device, and the processor is used to execute the method described in the first aspect or the second aspect of the present application.

[0007] In a fifth aspect, the present application provides a movable device in water areas, which includes a water area carrier and the propeller described in the fourth aspect of the present application, and the propeller is arranged on the water area carrier.

[0008] In the embodiment of the present application, after the position keeping function is enabled, the target thrust that can make the bow or stern of the water body face the target position and make the water body move forward or backward is calculated, and the target thrust is generated by controlling the propeller, so that the water body is kept at the target position. The present application can automatically maintain the position of the water body based on a single propeller, so that when the water body is equipped with only one propeller, the water movable device can also achieve automatic position maintenance without manual operation by the user, which greatly facilitates the use of the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0010] Figure 1 A schematic diagram of the structure of a movable device for water area according to one embodiment of the present application.

[0011] Figure 2 This is a schematic structural diagram of the connection between the lifting device and the clamp in a thruster according to an embodiment of the present application.

[0012] Figure 3 This is a schematic diagram of the module connections of a movable device in water area according to one embodiment of the present application.

[0013] Figure 4 This is a schematic diagram of module connections of a mobile device in water area according to another embodiment of the present application.

[0014] Figure 5 A schematic diagram of a coordinate system of a water body according to an embodiment of the present application.

[0015] Figure 6 A flowchart of a method for maintaining the position of a water body based on a single propeller according to an embodiment of the present application.

[0016] Figure 7 This is a schematic diagram of the principle of calculating the position of a water body according to an embodiment of the present application.

[0017] Figure 8 This is a schematic diagram of a first axis according to an embodiment of the present application.

[0018] Fig.9A and Fig. 9B They are schematic diagrams of the thrust direction of the target thrust of an embodiment of the present application.

[0019] Fig.10A schematic diagram of the principle of calculating the angle error according to an embodiment of the present application.

[0020] Fig.11A A schematic diagram of the steering position of a propeller according to an embodiment of the present application.

[0021] Fig. 11B A schematic diagram of the relationship between the angle error and the steering stroke according to an embodiment of the present application.

[0022] Fig. 12A and Fig. 12B They are schematic diagrams of the movement mode of a water body carrier according to an embodiment of the present application.

[0023] Fig.13 A schematic diagram of the change process of the thrust output of the propeller according to an embodiment of the present application.

[0024] Fig.14 This is a flow chart of a method for maintaining the position of a water vehicle based on a single propeller according to another embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0027] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items. Unless otherwise indicated, similar words such as "front", "rear", "bottom" and / or "top" are only for ease of explanation and are not limited to a position or a spatial orientation. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect. "Multiple" means at least two.

[0028] See also Figure 1 The present application provides a movable device 100 for water areas. The movable device 100 for water areas may be any type of water transportation vehicle such as a commercial ship, a passenger ship, a yacht, a fishing boat, a sailboat, a civilian ship, or may be any water area inspection equipment, water area management equipment, water area environment monitoring equipment, or other equipment capable of operating in water areas, and the present application does not limit this.

[0029] The water area movable device 100 comprises a water area carrier 20 and a propeller 10 disposed on the water area carrier 20. The propeller 10 is a device capable of providing power in a water area environment. The propeller 10 comprises a steerable member capable of rotating around a steering axis S( Figure 2 In one example, the steerable member may include a propulsion device 11 in the propeller 10. In this case, the propeller 10 may be an outboard motor, a rotatable pod propeller, a towing motor, etc. In another example, the steerable member may include a rudder blade. In this case, the propeller 10 includes a rudder blade and a propulsion device 11 that are independent of each other. For example, the propeller 10 may be an inboard motor used in combination with a rudder blade, wherein the rudder blade and the inboard motor are independent of each other. For example, when the propeller 10 is an outboard motor or a towing motor, the propeller 10 may be installed at the bow, stern, side, etc. of the water body carrier 20. For example, when the propeller 10 is a device including a rudder blade and an inboard motor or a rotatable pod propeller 10, the propeller 10 may be installed at the bottom of the water body carrier 20, etc.

[0030] See also Figure 1 and Figure 2 , taking the propeller 10 as an outboard motor as an example for schematic illustration, the propeller 10 includes a clamp 15 and a main body. The clamp 15 is used to fix the main body on the water body 20, for example, to fix the main body on the stern of the water body 20. The main body includes a propulsion device 11, a steering device 12, a tilting device 13 and a housing 14. The propulsion device 11, the steering device 12, and the tilting device 13 are all connected to the housing 14.

[0031] The propulsion device 11 includes a propulsion motor 111 and a propeller 112. The propeller 112 is mounted on the output shaft of the propulsion motor 111. When the propulsion motor 111 rotates, the propeller 112 is driven to rotate to output thrust. The propulsion motor 111 can output a first torque and a second torque with different directions. By switching the first torque and the second torque, the rotation direction of the propeller can be changed so that the propeller has two thrust output directions, thereby pushing the water body 20 forward or backward.

[0032] The steering device 12 includes a steering shaft 121, a reduction assembly 122 and a steering motor 123 connected in sequence. The steering motor 123 drives the steering shaft 121 to rotate left and right relative to the housing 14 through the reduction assembly 122. Since the housing 14 is rotated to fit the steering shaft 121, and the propulsion device 11 is relatively fixed to the housing 14, when the steering motor 123 drives the steering shaft 121 to rotate relative to the housing 14 through the reduction assembly 122, the propulsion device 11 can be rotated relative to the steering axis S, thereby changing the direction of the propulsion device 11, changing the direction of the thrust provided by the propulsion device 11, and then driving the water body 20 to turn. Further, the steering device 12 can also include a steering angle sensor (not shown), which can be used to detect the steering angle of the propulsion device 11.

[0033] The tilting device 13 includes a tilting shaft 131, a tilting bracket 132 and a tilting driving assembly 133. The tilting bracket 132 is connected to the clamp 15 for relative rotation via the tilting shaft 131, and the tilting driving assembly 133 is used to drive the tilting bracket 132 to rotate relative to the clamp 15. Since the tilting bracket 132 and the propulsion device 11 are relatively fixed in the tilting direction, the tilting bracket 132 can drive the propulsion device 11 to rotate relative to the tilting axis Q to achieve the tilting of the propulsion device 11. Furthermore, the tilting device 13 can also include a tilting angle sensor (not shown), which can be used to detect the tilting angle of the propulsion device 11.

[0034] See also Figure 3 and Figure 4 , the propeller 10 also includes a processor 16. The processor 16 is housed inside the housing 14. The processor 16 is electrically connected to the propulsion device 11, the steering device 12, and the tilting device 13. For example, the processor 16 can be electrically connected to the propulsion motor 111, the steering motor 123, the steering angle sensor, the tilting drive assembly 133, and the tilting angle sensor. The processor 16 can receive signals fed back by the propulsion motor 111, the steering motor 123, the steering angle sensor, the tilting drive assembly 133, and the tilting angle sensor, and can also output instructions to the propulsion device 11, the steering device 12, and the tilting device 13, so that the propulsion device 11, the steering device 12, and the tilting device 13 perform actions corresponding to the instructions.

[0035] Please continue reading Figure 3 and Figure 4 The water movable device 100 may further include a control device 30 , an inertial measurement sensor 40 and a global navigation satellite system 50 .

[0036] The control device 30 is used to receive the user's operation to send a control instruction corresponding to the user's operation to the propeller 10, and the control instruction includes, for example, a forward gear instruction, a reverse gear instruction, a steering instruction, etc. For example, the control device 30 can be electrically connected to the processor 16 to send the control instruction to the processor 16. The control device 30 can include, for example, a steering wheel, a tiller, a remote control controller, a wireless joystick, a display screen, etc.

[0037] The inertial measurement sensor 40 may include a three-axis accelerometer that can detect and output acceleration data. The inertial measurement sensor 40 may be electrically connected to the processor 16 to provide acceleration data to the processor 16. The acceleration data includes acceleration data of a roll axis, acceleration data of a pitch axis, and acceleration data of a yaw axis. The unit of acceleration is usually m / s. 2 By integrating the acceleration of each axis, the linear velocity and moving distance of each axis can be obtained. Figure 5 As shown, in the three-axis coordinate system of the water body 20, the X axis represents the roll axis, the Y axis represents the pitch axis, and the Z axis represents the yaw axis. The midline plane of the water body 20 is a plane perpendicular to the Y axis and passing through the axis of the X axis. The direction of the water body 20 can be understood as Figure 5 The positive direction of the X-axis shown in can also be called the bow direction of the ship.

[0038] The global navigation satellite system 50 can detect and output position data. The global navigation satellite system 50 can be electrically connected to the processor 16 to provide the processor 16 with position data. The global navigation satellite system 50 can be any one of the BeiDou Navigation Satellite System (BDS), the Global Positioning System (GPS), the Global Navigation Satellite System (GLONASS), and the Galileo Navigation Satellite System (Galileo), and the present application does not limit this.

[0039] like Figure 3As shown, the inertial measurement sensor 40 and the global navigation satellite system 50 can be directly set on the water body 20. At this time, the inertial measurement sensor 40 and the global navigation satellite system 50 are relatively fixed to the water body 20, and the data output by the inertial measurement sensor 40 and the global navigation satellite system 50 are detection data for the water body 20. In this setting mode, the detection data of the water body 20 can be directly obtained without conversion, which can reduce the amount of calculation required by the processor 16. Figure 4 As shown, the inertial measurement sensor 40 and the global navigation satellite system 50 can be arranged in the propeller. This arrangement can make the function of the propeller 10 more abundant, which is conducive to improving the integration of the propeller 10. Further, in the case where the steerable member includes a propulsion device 11, in order to facilitate the circuit connection between the inertial measurement sensor 40 and the global navigation satellite system 50 and the processor 16, the inertial measurement sensor 40 and the global navigation satellite system 50 can be arranged inside the housing 14. Since the housing 14 and the propulsion device 11 are fixedly connected, the inertial measurement sensor 40 and the global navigation satellite system 50 will move relative to the water body carrier 20 with the rotation (steering or tilting) of the propulsion device 11, and the data output by the inertial measurement sensor 40 and the global navigation satellite system 50 is the detection data for the propulsion device 11. Under this embodiment, the data output by the inertial measurement sensor 40 can be converted to obtain the detection data for the water body carrier 20. In the case where the global navigation satellite system 50 is set on the propeller 10, it can be understood that the position data output by the global navigation satellite system 50 is data in the world coordinate system, and whether it moves relative to the water body 20 with the rotation of the propulsion device 11 will not have a significant impact on the output position data. Therefore, it is only necessary to consider the distance difference between the position of the propeller 10 and the position of a certain target point of the water body 20 (i.e., the point used to characterize the position of the water body 20), and the processor 16 converts the position data of the propeller 10 into the position data of the water body 20 based on the distance difference. An exemplary conversion method can be found in the description below.

[0040] Based on the aforementioned water area movable device 100, the present application also provides a method for maintaining the position of a water area carrier 20 based on a single propeller 10. The method can be executed by the aforementioned processor 16. Figure 6 The method for maintaining the position of the water body 20 based on a single propeller 10 in the embodiment of the present application includes:

[0041] Step S11: In response to the position keeping instruction, the current position of the water area carrier 20 is used as the target position;

[0042] Step S12: Calculate the target thrust required by the propeller 10, the target thrust is used to make the bow or stern of the water body 20 face the target position, and make the water body 20 move forward or backward to maintain the target position;

[0043] Step S13: Control the thruster 10 to generate the target thrust.

[0044] In step S11, the position hold instruction is used to trigger the position hold function. The position hold function can be triggered in a variety of ways. As an example, the user can trigger the position hold function by operating the control device 30. For example, a position hold button is provided on the remote control controller, and the user presses the position hold button, and the control device 30 generates a position hold instruction and sends the position hold instruction to the processor 16 in the thruster 10. The processor 16 responds to the position hold instruction and starts to execute the position hold control. As another example, a position hold button may be provided on the thruster 10, and the position hold button is electrically connected to the processor 16. After the user presses the position hold button, the processor 16 detects the user's operation and generates a position hold instruction accordingly. The processor 16 responds to the position hold instruction and starts to execute the position hold control.

[0045] The target position may be the current position of the water body carrier 20 when the processor 16 receives the position keeping instruction. The processor 16 may obtain the current position data (i.e., when the position keeping instruction is received) from the global navigation satellite system 50 to determine the current position of the water body carrier 20 based on the position data. In an embodiment where the global navigation satellite system 50 is provided on the water body carrier 20, the processor 16 may directly obtain the current position of the water body carrier 20 based on the position data obtained by the global navigation satellite system 50. In an embodiment where the global navigation satellite system 50 is provided on the propeller 10, the processor 16 may obtain the position of the propeller 10 based on the position data obtained by the global navigation satellite system 50, and determine the position of the water body carrier 20 based on the position of the propeller 10 and the size of the water body carrier 20.

[0046] Specifically, the processor 16 may determine the position of a target point on the water area carrier 20 as the position of the water area carrier 20. Figure 7 As shown, X'O'Y' represents the world coordinate system. Assume that the length of the water body 20 is L, the width is W, the target point is the center point A of the water body 20, the position obtained by the global navigation satellite system 50 is (x, y), and the heading angle of the water body 20 is θ. If the thruster 10 is installed at the midpoint of the stern of the water body 20 (as shown by point B in the figure), the coordinates of the center point A of the water body 20 are (x A ,y A ), where x A and A satisfy:

[0047]

[0048] It can be understood that the method of calculating the position of the water body 20 in the above embodiment is only an exemplary description and is not intended to limit the present application. In other embodiments, the target point may be other points on the water body 20, and the propeller 10 may also be installed at other positions of the water body 20. In other embodiments, the position of the water body 20 may also be calculated based on the position of the propeller 10, the size of the water body 20, and the heading θ of the water body 20. The specific calculation method is determined according to the position of the target point and the position of the propeller 10, and will not be listed here one by one.

[0049] Since the detection frequency of the global navigation satellite system 50 is low, the global navigation satellite system 50 cannot output enough position data per unit time to assist the processor 16 in performing the position keeping adjustment, which will affect the realization of the position keeping. To this end, the processor 16 can perform interpolation processing, that is, insert one or more estimated position data between two adjacent position data output by the global navigation satellite system 50, so as to obtain a sufficient amount of position data to perform the position keeping adjustment. As an example, the processor 16 can obtain the position of the water body carrier 20 based on the position data output by the global navigation satellite system 50 and the moving distance of the water body carrier 20. The following is an example of the method of obtaining the position of the water body carrier 20.

[0050] In some embodiments, obtaining the position of the water body carrier 20 includes obtaining the latest position data output by the global navigation satellite system 50, and calculating the position of the water body carrier 20 based on the moving distance of the water body carrier 20 and the position data obtained by the global navigation satellite system 50. The moving distance is the distance moved by the water body carrier 20 in the period between the moment when the global navigation satellite system 50 outputs the latest position data and the current moment. For example, assuming that the moment when the global navigation satellite system 50 outputs the latest position data is T1, the current moment is T2, and the time interval between T1 and T2 is ΔT, the processor 16 can obtain the moving distance of the water body carrier 20 in the ΔT period, and determine the position of the water body carrier 20 at the moment T2 according to the moving distance and the position data output by the global navigation satellite system 50 at the moment T1.

[0051] The moving distance d of the water body 20 can be calculated based on the moving speed v of the propeller 10 and the heading angle θ of the water body 20. As an example, the processor 16 can obtain the power of the propeller 10 in the time interval △T, and obtain the moving speed of the water body 20 in the time interval △T according to the mapping relationship between the power and speed of the propeller 10, and then determine the moving distance of the water body 20 in the time interval △T based on the moving speed of the water body 20 in the time interval △T. Then, according to the heading angle θ of the water body 20, the above moving distance is decomposed into the X' axis and the Y' axis of the world coordinate system, and the moving distance component of the X' axis and the moving distance component of the Y' axis are obtained. The moving distance component of the X' axis is added to the position data of the X' axis at the time T1 output by the global navigation satellite system 50, and the position data of the water body 20 at the X' axis at the current time can be obtained; the moving distance component of the Y' axis is added to the position data of the Y' axis at the time T1 output by the global navigation satellite system 50, and the position data of the water body 20 at the Y' axis at the current time can be obtained. The current position data of the water area carrier 20 on the X' axis and the current position data of the water area carrier 20 on the Y' axis can indicate the current position of the water area carrier 20. It should be noted that the heading angle θ of the water area carrier 20 can be output by the global navigation satellite system 50, but in this embodiment, due to the low detection frequency of the global navigation satellite system 50, the processor 16 fails to obtain the heading angle θ output by the global navigation satellite system 50. Therefore, in this embodiment, the processor 16 can convert the heading angle θ based on the steering angle of the steerable member.

[0052] Alternatively, the moving distance of the water area carrier 20 can be calculated based on the acceleration data output by the inertial measurement sensor 40. The processor 16 can use a three-axis accelerometer to obtain the acceleration information of the roll axis X and the pitch axis Y, and then perform secondary integration on the acceleration information of the roll axis X and the pitch axis Y to obtain the moving distances of the roll axis X and the pitch axis Y, and then convert the moving distances of the roll axis X and the pitch axis Y to the world coordinate system to obtain the moving distance components of the X' axis and the Y' axis of the world coordinate system. The processor 16 then adds the moving distance component of the X' axis to the position data of the X' axis at the time T1 output by the global navigation satellite system 50 to obtain the position data of the water area carrier 20 on the X' axis at the current time, and adds the moving distance component of the Y' axis to the position data of the Y' axis at the time T1 output by the global navigation satellite system 50 to obtain the position data of the water area carrier 20 on the Y' axis at the current time. The current position data of the water area carrier 20 on the X' axis and the current position data of the water area carrier 20 on the Y' axis can indicate the current position of the water area carrier 20. It can be understood that the detection frequency of the inertial measurement sensor 40 is higher than the detection frequency of the global navigation satellite system 50, so the position data of the water area carrier 20 can be estimated with the help of the data of the inertial measurement sensor 40. In this way, the processor 16 can obtain enough position data to better perform position keeping adjustment.

[0053] In step S12, calculating the target thrust required by the propeller 10 may include calculating the thrust direction of the target thrust required by the propeller 10. The thrust direction of the target thrust is used to make the target position fall on the first axis of the water body 20, wherein the first axis is parallel to the rolling axis X of the water body 20. Figure 8 As shown, the first axis may be the axis indicated by the long dashed line N1 in the figure, or the axis indicated by the short dashed line N2 in the figure, or other axes parallel to the rolling axis X, or the first axis may also coincide with the rolling axis X of the water body 20. It can be understood that the processor 16 sets the thrust direction of the target thrust to cause the target position to fall on the first axis parallel to the rolling axis X of the water body 20, thereby causing the bow or stern of the water body 20 to face the target position. At this time, the processor 16 further adjusts the rotation direction of the propeller 112 to make the water body 20 move forward or backward, so that the water body 20 moves in the direction close to the target position, and finally achieves the position maintenance of the water body 20.

[0054] like Fig.9AAs shown, when the bow of the water vehicle 20 is closer to the target position than the stern of the water vehicle 20 (assuming that the target position is the origin O' of the world coordinate system X'O'Y'), the target thrust is used to make the bow of the water vehicle 20 face the target position and make the water vehicle 20 move forward to maintain the target position. In this embodiment, the direction of the target thrust is as indicated by the gray arrow, and the target thrust may include a first component toward the positive direction of the roll axis X (i.e., the direction in which the stern of the water vehicle 20 points to the bow), and may also include a second component perpendicular to the first component. Among them, the first component can make the water vehicle 20 move forward, so that the bow of the water vehicle 20 is close to the target position. The second component can change the direction of the bow of the water vehicle 20, so that the bow of the water vehicle 20 faces the target position. When the bow of the water vehicle 20 is closer to the target position, the water vehicle 20 is moved forward by applying a positive target thrust toward the roll axis X, so that the water vehicle 20 can be kept at the target position with lower control complexity and shorter time.

[0055] like Fig. 9B As shown, when the stern of the water body 20 is closer to the target position than the bow of the water body 20 (assuming that the target position is the origin O' of the world coordinate system X'O'Y'), the target thrust is used to make the stern of the water body 20 face the target position and make the water body 20 retreat to maintain the target position. In this embodiment, the direction of the target thrust is as indicated by the gray arrow, and the target thrust may include a third component toward the negative direction of the roll axis X (i.e., the direction from the bow of the water body 20 to the stern), and may also include a fourth component perpendicular to the third component. Among them, the third component can make the water body 20 retreat, so that the stern of the water body 20 is close to the target position. The fourth component can change the direction of the stern of the water body 20, so that the stern of the water body 20 faces the target position. When the stern of the water body vehicle 20 is closer to the target position, the water body vehicle 20 is moved backward by applying a negative target thrust toward the roll axis X, so that the water body vehicle 20 can be kept at the target position with lower control complexity and shorter time.

[0056] In some embodiments, calculating the target thrust required by the propeller 10 includes: obtaining the subsequent position of the water carrier 20, calculating the angular error between the subsequent position and the target position, and determining the thrust direction of the target thrust based on the angular error. The subsequent position of the water carrier 20 can be understood as the real-time position of the water carrier 20 after the processor 16 receives the position holding instruction. The method for obtaining the subsequent position of the water carrier 20 can refer to the method for obtaining the current position of the water carrier 20 in the aforementioned embodiment, which will not be repeated here. The angular error is used to indicate the deviation between the orientation of the water carrier 20 and the orientation of the target position. For example, Fig.10In the illustrated embodiment, the angle α between the line between the center point of the water area vehicle 20 and the target position (assuming the origin O' of the world coordinate system X'O'Y') and the roll axis X of the water area vehicle 20 can be determined as the angle error.

[0057] In some embodiments, calculating the angular error between the subsequent position and the target position includes: obtaining the distance between the subsequent position and the target position, obtaining a first projection distance of the distance on a first axis of the water body 20 and a second projection distance of the distance on a second axis of the water body 20, wherein the first axis is parallel to the rolling axis X of the water body 20 and perpendicular to the second axis, and calculating the angular error based on the first projection distance and the second projection distance. Figure 8 The second axis is perpendicular to the first axis, and the second axis can be the pitch axis Y of the water body 20, or other axis parallel to the pitch axis Y. Fig.10 Assuming that the first axis is the roll axis X, the second axis is the pitch axis Y, and assuming that the distance between the subsequent position and the target position is recorded as D, the distance D can be decomposed into a first projection distance D according to the posture data of the water area carrier 20 (which can be measured by the inertial measurement sensor 40 on the water area carrier 20). x and the second projection distance D y According to the first projection distance D x and the second projection distance D y The ratio of can be obtained as follows angle error α:

[0058]

[0059] In the case where the propeller 10 includes a steerable member, the thrust direction of the target thrust is related to the steering position of the steerable member. Specifically, when the steerable member includes a propulsion device 11 in the propeller 10, the thrust direction is related to the steering position of the propulsion device 11; when the steerable member includes a rudder blade, the thrust direction is related to the steering position of the rudder blade. Determining the thrust direction of the target thrust based on the angle error may include determining the target steering position of the steerable member based on the angle error. It should be pointed out that in the case where the target position has fallen on the axis of the roll axis of the water body carrier 20, it means that the angle error between the subsequent position and the target position at this time is 0°, and it is required that when the steerable member is in the target steering position, the target thrust generated by the propulsion device 11 is only used to prompt the water body carrier 20 to move forward or backward, and does not prompt the water body carrier 20 to turn. For the case where the target position does not fall on the rolling axis of the water body 20, it means that the angular error between the subsequent position and the target position is not 0°. It is required that when the steerable part is in the target steering position, the target thrust generated by the propulsion device 11 needs to be able to prompt the water body 20 to turn, that is, the target thrust needs to be able to provide steering torque for the water body 20; at the same time, the target thrust generated by the propulsion device 11 can prompt the water body 20 to move forward or backward.

[0060] Regarding the target steering position of the steerable member, the steerable member including the propulsion device 11 is used as an example for explanation. Fig.11A , as an example, the target steering position may be located between the reference position P0 and the extreme position P2. It should be noted that in the various embodiments of the present application, unless otherwise specified, "located between..." should be understood to include endpoint values. Among them, the reference position P0 is the position where the axis of the thrust direction of the propulsion device 11 passes through the center point of the water body carrier 20, wherein the center point is the intersection of the rotation axis around which the water body carrier 20 rotates when the water body carrier 20 rotates in situ and the roll axis of the water body carrier 20. The extreme position P2 is the maximum position to which the propulsion device 11 can rotate compared to the reference position P0. In one embodiment of the present application, the rotation of the propulsion device 11 to the reference position P0 can be understood as the steering angle of the propulsion device 11 being 0°, and the rotation of the propulsion device 11 to the extreme position P2 can be understood as the steering angle of the propulsion device 11 being the maximum steering angle. In particular, in Fig.11AIn the example shown, when the propulsion device 11 rotates to the reference position P0, the direction of the thrust generated by the propulsion device 11 is parallel to the centerline plane of the water body 20, and the axis of the direction passes through the center point of the water body 20. At this time, the thrust cannot provide steering torque for the water body 20. Therefore, it is necessary to set the target steering position to deviate from the reference position P0 so that the water body 20 can turn. Similarly, when the propulsion device 11 rotates to the reference position P0, the axis of the thrust direction of the propulsion device 11 passes through the center point of the water body 20, but the thrust direction is not parallel to the centerline plane of the water body 20, the target steering position is also set to deviate from the reference position P0 so that the water body 20 can turn.

[0061] The number of extreme positions P2 can be one or two. Fig.11A As shown, when the number of extreme positions P2 is two, the two extreme positions P2 are located at opposite sides of the reference position P0, wherein one extreme position P2 is closer to the port side of the water body 20 than the reference position P0, and the other extreme position P2 is closer to the starboard side than the reference position P0. The steering angles corresponding to the two extreme positions P2 can be distinguished by positive and negative signs. For example, the steering angle corresponding to the reference position P0 is 0°, the steering angle corresponding to one extreme position P2 is -100°, and the steering angle corresponding to the other extreme position P2 is 100°. Specifically, the steering angle corresponding to the extreme position P2 that is closer to the port side of the water body 20 (hereinafter referred to as close to the port side) than the reference position P0 can be set to a negative value, and the steering angle corresponding to the extreme position P2 that is closer to the starboard side of the water body 20 (hereinafter referred to as close to the starboard side) than the reference position P0 can be set to a positive value; or, the steering angle corresponding to the extreme position P2 close to the starboard side can be set to a negative value, and the steering angle corresponding to the extreme position P2 close to the port side can be set to a positive value, and the present application does not impose any restrictions on this.

[0062] Determining the target steering position of the steerable member based on the angle error may specifically be determining the target steering angle of the steerable member based on the angle error, the target steering angle being the steering angle of the steerable member at the target steering position. Fig.11A, there are multiple positions between the reference position P0 and the extreme position P2. The target steering position can be any position between the reference position P0 and the extreme position P2 (except the reference position P0), and the specific position between the reference position P0 and the extreme position P2 can be determined according to the angular error between the subsequent position and the target position. In some embodiments, the steering stroke of the steerable member from the reference position P0 to the target steering position is positively correlated with the angular error. Specifically, the smaller the angular error, the smaller the steering stroke from the target steering position to the reference position P0, that is, the smaller the angular difference between the target steering position and the reference position, and the closer the target steering position is to the reference position; the larger the angular error, the larger the steering stroke from the target steering position to the reference position P0, that is, the larger the angular difference between the target position and the reference position, and the closer the target steering position is to the extreme position P2. As Fig. 11B As shown in the figure, P3 and P4 represent two different target positions, and the steering stroke from the target position P4 to the reference position P0 is greater than the steering stroke from the target position P3 to the reference position P0. When the angle error is α1, the target steering position is shown as P3; when the angle error is α2 which is greater than α1, the target steering position is shown as P4. It can be seen that the steering stroke corresponding to the target steering position P3 is smaller than the steering stroke corresponding to the target steering position P4.

[0063] It can be understood that when the angle error is smaller, it means that the deviation of the target position relative to the first axis of the water body 20 is smaller. At this time, only a smaller steering torque is needed to push the water body 20 so that the target position falls on the first axis; when the angle error is larger, it means that the deviation of the target position relative to the first axis of the water body 20 is larger. At this time, a larger steering torque is needed to push the water body 20 so that the target position falls on the first axis. The magnitude of the steering torque is related to the steering angle of the steerable member. The larger the steering angle of the target steering position where the steerable member is located, the greater the steering torque that the propeller 10 can provide for the water body 20. Therefore, by adaptively adjusting the steering angle of the steerable member through the angle error, the posture of the water body 20 can be better adjusted to ensure the realization of the position keeping function.

[0064] In the case where the bow of the water vehicle 20 is closer to the target position than the stern, when the steerable member is in the target steering position, the target thrust generated by the propulsion device 11 can cause the water vehicle 20 to turn, so that the bow of the water vehicle 20 faces the target position and the water vehicle 20 moves forward. Fig. 12AAssuming that at a certain moment, the position and orientation of the water body carrier 20 are as shown by the solid line pattern in the figure, the thrust direction of the target thrust at that moment is indicated by the gray arrow. Under the action of the target thrust, after a period of time, the position and orientation of the water body carrier are as shown by the dotted line pattern in the figure. It can be seen that under the action of the target thrust, the direction of the water body carrier 20 rotates clockwise, so that the bow of the water body carrier 20 faces the target position, and the water body carrier 20 moves forward, so as to get closer to the target position.

[0065] When the stern of the water vehicle 20 is closer to the target position than the bow, when the steerable member is in the target steering position, the target thrust generated by the propulsion device 11 can cause the water vehicle 20 to turn so that the stern of the water vehicle 20 faces the target position and the water vehicle 20 moves backward. Fig. 12B Assuming that at a certain moment, the position and orientation of the water body carrier 20 are as shown by the solid line pattern in the figure, the thrust direction of the target thrust at that moment is indicated by the gray arrow. Under the action of the target thrust, after a period of time, the position and orientation of the water body carrier are as shown by the dotted line pattern in the figure. It can be seen that under the action of the target thrust, the direction of the water body carrier 20 rotates clockwise, so that the stern of the water body carrier 20 faces the target position, and the water body carrier 20 moves backward, so as to get closer to the target position.

[0066] When the target position falls on the axis where the pitch axis of the water body vehicle 20 is located, the propulsion device 11 can generate a target thrust for making the bow of the water body vehicle 20 face the target position, and can also generate a target thrust for making the stern of the water body vehicle 20 face the target position, without limitation here. In particular, if the propulsion device 11 can output a thrust in a direction parallel to the pitch axis and passing through the center point of the water body vehicle 20, then in the case where the target position falls on the axis where the pitch axis of the water body vehicle 20 is located, the propulsion device 11 can output a thrust in this direction to cause the water body vehicle 20 to translate in the direction of the pitch axis to gradually approach the target position until it reaches the target position.

[0067] The above embodiments are only exemplary and are not intended to limit the present application. In other embodiments, thrusts in other directions may also be applied to make the water body carrier 20 turn and move in other ways to achieve position retention, which will not be listed here one by one.

[0068] In some embodiments, the target steering position is determined based on the angle error and the predetermined steering parameter. For example, the steering angle of the target steering position can be equal to the product of the angle error and the predetermined steering parameter. Among them, the predetermined steering parameter is a pre-calibrated fixed value, for example, a value that has been calibrated and stored before the propeller 10 leaves the factory. There can be one or more predetermined steering parameters. When there are multiple predetermined steering parameters, in actual use, the corresponding predetermined steering parameters can be selected for use based on the current application scenario of the propeller 10. It should be pointed out that, with the understanding of "predetermined steering parameters" here, the "predetermined" parameters mentioned in other embodiments of the present application can be understood as parameters that have been set before leaving the factory, and will not be repeated below. Assuming that the angle error is denoted as α and the predetermined steering parameter is denoted as k, the steering angle P of the target steering position can be recorded as:

[0069] P = k * α.

[0070] In this way, by using pre-calibrated parameters to realize the conversion of angle error to the corresponding target steering angle, a more suitable steering angle can be determined. The propeller 10 operates at this steering angle, which can better drive the water body carrier 20 to turn, thereby making the target position fall on the first axis of the water body carrier 20 faster and more accurately.

[0071] In some embodiments, calculating the target thrust required by the propeller 10 also includes calculating the thrust size of the target thrust required by the propeller 10. Specifically, calculating the target thrust required by the propeller 10 also includes: calculating the distance error between the subsequent position and the target position, and calculating the thrust size of the target thrust based on the distance error. The distance error is the distance between the subsequent position of the water body carrier 20 and the target position, and the thrust size may be positively correlated with the distance error. When the water body carrier 20 is far away from the target position, a greater thrust is usually required to move the water body carrier 20 to approach the target position. This is because the water body carrier 20 encounters greater resistance in the water and needs to overcome greater friction to move. A larger target thrust can produce a greater acceleration, thereby overcoming resistance to achieve a higher speed and improve position keeping efficiency. Assume that the coordinates of the target point on the water body carrier 20 are (x A ,y A ), the coordinates of the target position are (x, y), then the distance error △d can be expressed by the Euclidean distance between the target point and the target position, recorded as:

[0072]

[0073] Optionally, the thrust magnitude may be determined based on the distance error Δd and a predetermined distance parameter m, wherein the predetermined distance parameter m is a pre-calibrated fixed value. For example, the thrust magnitude may be equal to the product of the distance error Δd and the predetermined distance parameter m, and the thrust magnitude F may be expressed as:

[0074] F = Δd*m.

[0075] In this way, by using pre-calibrated parameters to achieve the conversion of distance error to corresponding thrust size, a target thrust with a more appropriate thrust size can be determined. The thruster 10 operates at this target thrust, which can better push the water vehicle 20 forward or backward, thereby enabling the water vehicle 20 to reach the target position faster and more accurately.

[0076] Furthermore, there may be multiple predetermined distance parameters. It is understandable that different types of water carriers 20 have different characteristic parameters (such as mass, size, etc.), and accordingly, the conversion relationship from distance error to thrust may also be different. Therefore, multiple predetermined distance parameters may be pre-calibrated, and different predetermined distance parameters may be used to convert distance error to thrust for different types of water carriers 20, so that the final thrust can be more consistent with the characteristics of the water carrier 20, thereby facilitating the movement control of the water carrier 20.

[0077] In some embodiments, calculating the thrust magnitude of the target thrust based on the distance error includes: obtaining the moving speed of the water body 20 at the subsequent position, calculating the speed error between the moving speed and the expected speed when the water body 20 reaches the target position, and calculating the thrust magnitude of the target thrust based on the distance error and the speed error. Among them, the expected speed when the water body 20 reaches the target position can be less than the predetermined speed threshold, that is, when the water body 20 reaches the target position, the speed of the water body 20 approaches 0m / s (including the case of being equal to 0m / s). For example, assuming that the moving speed of the water body 20 at the subsequent position is 3m / s and the expected speed is 0, the speed error is -3m / s. By setting the expected speed, the water body 20 can effectively reduce the situation where it continues to move after reaching the target position, causing the water body 20 to deviate from the target position again, and then needs to continue to adjust to correct the deviation, thereby minimizing the adjustment action required for the water body 20 to maintain the target position, reducing the shaking feeling caused by the position adjustment of the water body 20, and improving the user experience.

[0078] The above-mentioned moving speed and expected speed include the speed of the water body carrier 20 on the first axis, and the first axis is parallel to the rolling axis X of the water body carrier 20. In some embodiments, the moving speed of the water body carrier 20 at the subsequent position can be measured by the inertial measurement sensor 40. This method has low complexity, and the measurement frequency of the inertial measurement sensor 40 is high, so the real-time performance of the obtained speed is high. In other embodiments, the moving speed of the water body carrier 20 at the subsequent position can be jointly acquired based on the inertial measurement sensor 40 and the global navigation satellite system 50. By jointly acquiring the moving speed of the water body carrier 20 through the inertial measurement sensor 40 and the global navigation satellite system 50, the accuracy of the acquired moving speed can be effectively improved.

[0079] Specifically, obtaining the moving speed of the water body carrier 20 at the subsequent position includes: calculating the first speed of the water body carrier 20 on the first axis based on the acceleration data output by the inertial measurement sensor 40, determining the second speed of the water body carrier on the first axis based on the speed data output by the global navigation satellite system 50, fusing the first speed and the second speed, and obtaining the moving speed of the water body carrier at the subsequent position. The first speed can be obtained by integrating the acceleration data output by the inertial measurement sensor 40. The global navigation satellite system 50 can obtain multiple (for example, two) position data of the water body carrier 20, and determine the moving distance of the water body carrier 20 based on the above two position data, and determine the moving speed of the water body carrier 20 based on the above moving distance and the acquisition time interval of the two position data. The moving speed obtained by the global navigation satellite system 50 is decomposed onto the first axis to obtain the second speed. Fusion of the first speed and the second speed can be weighted processing of the first speed and the second speed.

[0080] In some embodiments, the thrust magnitude is positively correlated with the distance error, and the thrust magnitude is positively correlated with the speed error. Optionally, the thrust magnitude is determined based on the speed error, the distance error and a predetermined parameter, and the predetermined parameter may include at least one of a predetermined distance parameter m or a predetermined speed parameter n. In an example where both the predetermined distance parameter m and the predetermined speed parameter n are used, the distance error Δd may be weighted based on the predetermined distance parameter m, and the speed error Δv may be weighted based on the predetermined speed parameter n, and the thrust magnitude is obtained based on the weighted distance error and the weighted speed error. The thrust magnitude F may be expressed as:

[0081] F = m*Δd+n*Δv.

[0082] In this way, by using pre-calibrated parameters to realize the conversion of distance error and speed error into corresponding thrust magnitude, a target thrust with a more appropriate thrust magnitude can be determined. The propeller 10 operates at this target thrust, which can better push the water vehicle 20 forward or backward, thereby enabling the water vehicle 20 to reach the target position faster and more accurately.

[0083] Furthermore, there may be multiple predetermined parameters. It is understandable that different types of water carriers 20 have different characteristic parameters (such as mass, size, etc.), and accordingly, the conversion relationship from distance error and speed error to thrust may also be different. Therefore, multiple predetermined parameters may be pre-calibrated, and different predetermined parameters may be used to convert distance error and speed error to thrust for different types of water carriers 20, so that the final thrust size can be more consistent with the characteristics of the water carrier 20, thereby facilitating the movement control of the water carrier 20.

[0084] In step S13, after calculating the target thrust required by the propulsion device 11, considering that different types of propellers 10 may use different propulsion motors 111 and propellers 112, resulting in different types of propellers 10 outputting target thrusts. The operating parameters used may be different, therefore, controlling the propeller 10 to generate the target thrust may include: based on the mapping relationship between the thrust size of the propeller 10 and the operating parameters, determining the target operating parameters that match the thrust size of the target thrust, and controlling the propeller 10 to operate with the target operating parameters to generate the target thrust. Among them, the mapping relationship between the thrust size and the operating parameters can be pre-calibrated information, which can be pre-stored in the propeller 10 to facilitate the call of the processor 16. The operating parameters can be, for example, parameters such as power, current, and voltage, which are not limited in this application.

[0085] It should be noted that the actions of calculating the target thrust and controlling the propulsion device 11 to generate the target thrust can be understood as an adjustment cycle. To achieve the position maintenance of the water body 20, the processor 16 may only need to perform one adjustment cycle to move the subsequent position of the water body 20 to the target position, or may need to perform multiple adjustment cycles to move the subsequent position of the water body 20 to the target position. Fig.13, assuming that the target position is the origin of the world coordinate system X'O'Y'. At time T1, the water carrier 20 is facing the Y'-axis direction of the world coordinate system X'O'Y', and the angular error of the water carrier 20 is α1. The direction of the target thrust is indicated by the gray arrow in the figure. Under the action of the target thrust, the water carrier 20 begins to move and turn clockwise (as shown by the dotted arrow in the figure). At time T2 after time T1, the angular error of the water carrier 20 is α2, and α2 is less than α1. As the angular error of the water carrier 20 changes, the thrust direction of the target thrust also changes. Under the action of the changed target thrust, the posture of the water carrier 20 continues to change, and at time T3 after time T2, the angular error further decreases from α2 to α3, and the thrust direction of the target thrust continues to change with the angular error. At time T4, the water carrier 20 reaches the target position and the position maintenance is completed. It should be noted that at Fig.13 In the process, the position of the water area carrier 20 is made to coincide with the target position by performing position keeping control. However, in actual application, as long as the distance between the position of the water area carrier 20 and the target position is within the set range, it is considered that the water area carrier 20 has been maintained at the target position, and there is no requirement that the position of the water area carrier 20 strictly coincide with the target position.

[0086] In the present application, in addition to calculating the thrust magnitude of the target thrust and generating the target thrust based on the calculated thrust magnitude, a target thrust of a predetermined thrust value may be generated, or a target thrust corresponding to a predetermined operating parameter may be generated.

[0087] In the case where the thrust magnitude of the target thrust is a predetermined thrust value, the predetermined thrust value may be a manually set thrust value or a default thrust value. Similarly, there is a mapping relationship between the thrust magnitude of the propeller 10 and the operating parameters, and therefore, controlling the propeller 10 to generate the target thrust includes: determining a target operating parameter matching the predetermined thrust value based on the mapping relationship between the thrust magnitude of the propeller 10 and the operating parameters, and controlling the propeller 10 to operate with the target operating parameter to generate the target thrust.

[0088] In the case of generating a target thrust corresponding to a predetermined operating parameter, controlling the propeller 10 to generate the target thrust includes: controlling the propeller 10 to operate with the predetermined operating parameter to generate the target thrust. In this embodiment, the target thrust does not need to be calculated, but the propeller 10 is directly set to operate with the predetermined operating parameter, so as to generate the target thrust corresponding to the predetermined operating parameter.

[0089] It should be noted that, in the case where the thrust magnitude of the target thrust is a predetermined thrust value, the processor 16 determines the target operating parameters that match the predetermined thrust value in the first adjustment cycle, and operates with the target operating parameters in the first adjustment cycle and subsequent adjustment cycles. Therefore, in subsequent adjustment cycles, the processor 16 only needs to adjust the steering angle of the steerable member. In the case where the thruster 10 operates with the predetermined operating parameters, in each adjustment cycle, the processor only needs to adjust the steering angle of the steerable member without calculating the target operating parameters.

[0090] In the above embodiment of the present application, during the activation of the position keeping function, the propeller 10 simultaneously adjusts the thrust direction and outputs the thrust magnitude, so as to gradually move the bow or stern of the water body 20 toward the target position, and at the same time, gradually move the water body 20 closer to the target position. This synchronous adjustment method can make the water body 20 reach the target position faster, and improve the efficiency of position keeping.

[0091] The method of the present application also includes: when the distance error between the subsequent position of the water carrier 20 and the target position is within a predetermined error range, the propeller 10 is controlled to stop generating thrust. When the subsequent position of the water carrier 20 is close to the target position, the water carrier 20 can continue to move under the action of inertia to reach the target position. Therefore, when the distance error is within the predetermined error range, the propeller 10 can be controlled to stop generating thrust. In this way, on the one hand, the water carrier 20 can reach the target position at a lower speed to prevent the water carrier 20 from still having a certain speed when it reaches the target position and continuing to deviate from the target position; on the other hand, the propeller 10 is controlled to stop generating thrust in advance before reaching the target position, which can reduce the energy consumption of the water carrier 20. It should be noted that the processor 16 controls the propulsion device 11 to stop the thrust output, which does not mean that the propeller 10 exits the position holding function. It should be understood that the stop operation at this time is only because the position of the water carrier 20 has approached the target position, and no adjustment is required, and the position holding function is still enabled. Once the position of the water carrier 20 deviates from the target position, the processor 16 will continue to control the propulsion device 11 to generate thrust.

[0092] In the method of the embodiment of the present application, since the steering angle and thrust of the propulsion device 11 need to be determined and executed autonomously by the processor 16 according to information such as angle error and speed error during the period when the position holding function is turned on, and cannot be determined based on the steering and other instructions generated by the control device 30 after the user operates the control device 30. Therefore, the method of the present application needs to be executed when the movable parts of the control device 30 are not activated, wherein the control device 30 includes but is not limited to the throttle lever, the control button, the steering wheel, the tiller, etc. Inactivation can be understood as the control device 30 not receiving the user's operation. For example, the movable part of the control device 30 is a component for receiving the user's steering operation, such as the steering wheel, the handle of the tiller, etc. The inactivation of the control device 30 may include that the control device 30 does not receive the user's steering control operation. Accordingly, the method of the present application can be executed when the propeller 10 does not receive the steering instruction sent by the control device 30. Alternatively, the movable part of the control device 30 is a component for receiving the user's throttle operation, such as the throttle lever of the remote control controller, the joystick of the wireless joystick, etc. The control device 30 is not activated, which may include that the control device 30 has not received the user's throttle control operation. Accordingly, the method of the present application can be executed when the propeller 10 does not receive the throttle command sent by the control device 30. When the control device 30 is activated, it usually indicates that the user needs to control the propeller 10. Therefore, in this case, the position holding control may not be performed, but the propeller 10 is controlled in response to the control command output by the user through the control device 30, so that the control process of the propeller 10 meets the user's operation requirements. When the movable part of the control device 30 is not activated, it usually indicates that the user has no need to operate the propeller 10. At this time, the position holding control can be performed to keep the water body 20 at the target position.

[0093] During the period when the position holding function is turned on, the user may operate the control device 30. For this scenario, the method of the present application also includes: during the period when the propeller 10 performs the position holding control, if the propeller 10 receives the moving instruction of the mobile water carrier 20 sent by the control device 30, after the propeller 10 executes the moving instruction, and the water carrier 20 meets the state maintenance condition, the position holding control continues to be performed, and the control device 30 is used to control the propeller 10. As an example, the state maintenance condition includes that the deviation value of the position of the water carrier 20 after moving from the target position is less than the first deviation threshold. That is, when the deviation value is less than the first deviation threshold, the position holding function continues to be turned on, and the processor 16 continues to perform the position holding control. When the deviation value reaches (equal to or greater than) the first deviation threshold, the propeller 10 exits the position holding function, and the processor 16 controls the operation of components such as the propulsion device 11 based on the instruction sent by the control device 30. In this way, the propeller 10 can automatically exit the position holding function without the user having to manually operate, reducing human intervention, and having higher convenience and better user experience. In the embodiment of the present application, the first deviation threshold may be 0.5m, 0.7m, 0.8m, etc., and the present application does not impose any limitation on this.

[0094] For the case where the deviation value is less than the first deviation threshold, the processor 16 continues to perform the position keeping control, which may include: when the deviation value is between the second deviation threshold and the first deviation threshold, the position of the water body carrier 20 after moving is updated to the target position, and the position keeping control is continued; when the deviation value is less than the second deviation threshold, the target position is kept unchanged, and the position keeping control is continued. Among them, the second deviation threshold is less than the first deviation threshold. The second deviation threshold can be 0.2m, 0.3m, 0.4m, etc., and the present application does not limit this. It can be understood that when the deviation value is less than the second deviation value, it means that the user may have misoperated the control device 30 at this time, causing the thruster 10 to work in response to the instruction of the control device 30, thereby causing the movement of the water body carrier 20. Therefore, for this situation, the processor 16 can consider it as a case of user misoperation, and the user subjectively does not want to change the target position. The processor 16 still performs the position keeping control based on the original target position. In this way, the problem of exiting the position keeping function caused by user misoperation can be avoided. When the deviation value is between the second deviation threshold and the first deviation threshold, the water body 20 rotates a relatively large angle, but does not exceed the rotation amplitude corresponding to the first deviation threshold, indicating that the user may want to fine-tune the target position of the water body 20. Therefore, in this case, the processor 16 can use the position of the water body 20 after it moves as the new target position. In subsequent control, the processor 16 performs position keeping control based on the new target position. In this way, the user does not need to perform the operation of enabling the position keeping function again when fine-tuning the target position, and the thruster 10 can automatically perform the position keeping function, which is more convenient for the user to operate.

[0095] It should be pointed out that the method of the present application is not only applicable to the case where the water carrier 20 is only equipped with one propeller 10, but also applicable to the case where the water carrier 20 is equipped with multiple (such as two, three, four, etc.) propellers 10. For the case where the water carrier 20 is equipped with multiple propellers 10, during the period when the position keeping function is enabled, the processor 16 can only enable one propeller 10 among the multiple propellers 10 to perform position keeping control. Among them, the one propeller 10 can be any one propeller 10 among the multiple propellers 10. The method of the present application also includes: detecting whether there are other propellers in a working state on the water carrier 20, and if not, executing the step of calculating the target thrust required by the propeller 10. If it exists, the step of calculating the target thrust required by the propeller 10 may not be executed, and a prompt message may also be output to prompt the user that the propeller 10 does not perform position keeping control.

[0096] In the case where multiple propellers 10 are installed on the water body 20, one of the multiple propellers 10 can be set as the host, and the other propellers 10 in the multiple propellers 10 can be set as the host. The position keeping control can be performed by the host. The processor 16 can determine the host among the multiple propellers 10 and control the host to perform the position keeping control.

[0097] Alternatively, the position keeping control mode can also be determined according to the number of propellers 10 in working state. Among them, the position keeping control mode includes a single-machine mode and a multi-machine mode. When the number of propellers 10 in working state is 1, the single-machine mode can be entered, so as to perform the step of calculating the target thrust required by the propeller 10, so as to achieve the position keeping of the water area vehicle 20 based on a single propeller 10. When the number of propellers 10 in working state is greater than 1, the multi-machine mode can be entered, so as to achieve the position keeping of the water area vehicle 20 based on multiple propellers 10.

[0098] Each thruster 10 includes a processor 16, and the processors 16 of multiple thrusters 10 are connected to the same bus. According to the number of processors 16 connected to the bus, the number of thrusters 10 in working state can be determined. When the thruster 10 is connected to the bus, the processor 16 of the thruster 10 can send a signal to the bus.

[0099] See also Fig.14 The present application also provides a method for maintaining the position of a water body based on a single propeller, the method comprising:

[0100] Step S21: In response to the position keeping instruction, the current position of the water area carrier 20 is used as the target position;

[0101] Step S22: obtaining the subsequent position of the water area carrier 20;

[0102] Step S23: Calculate the angle error between the subsequent position and the target position;

[0103] Step S24: determining the thrust direction of the target thrust required by the thruster 10 based on the angle error;

[0104] Step S25: Control the propeller 10 to generate a target thrust in the thrust direction so that the water body 20 remains at the target position.

[0105] The specific details of this embodiment are detailed in the aforementioned method embodiment and will not be repeated here.

[0106] In some embodiments, the position of the water vehicle 20 is acquired based on a global navigation satellite system 50 .

[0107] In some embodiments, the global navigation satellite system 50 is disposed on the water vehicle 20 .

[0108] In some embodiments, the global navigation satellite system 50 is disposed on the thruster 10 .

[0109] In some embodiments, obtaining the position of the water body carrier 20 includes: obtaining the position of the propeller 10 and the size of the water body carrier 20 ; and determining the position of the water body carrier 20 based on the position of the propeller 10 and the size of the water body carrier 20 .

[0110] In some embodiments, the position of the water vehicle 20 is acquired based on a global navigation satellite system 50 and an inertial measurement sensor 40 .

[0111] In some embodiments, obtaining the position of the water body carrier 20 includes: obtaining the latest position data output by the global navigation satellite system 50; calculating the moving distance of the water body carrier 20 based on the acceleration data output by the inertial measurement sensor 40, where the moving distance is the distance moved by the water body carrier 20 in the period from the moment when the global navigation satellite system 50 outputs the latest position data to the current moment; and calculating the position of the water body carrier 20 based on the position data and the moving distance.

[0112] In some embodiments, obtaining the position of the water carrier 20 includes: obtaining the latest position data output by the global navigation satellite system 50; calculating the moving distance of the water carrier 20 based on the moving speed of the propeller 10 and the heading of the water carrier 20, where the moving distance is the distance moved by the water carrier 20 in the period from the moment when the global navigation satellite system 50 outputs the latest position data to the current moment; and calculating the position of the water carrier 20 based on the position data and the moving distance.

[0113] In some embodiments, calculating the angular error between the subsequent position and the target position includes: obtaining the distance between the subsequent position and the target position; obtaining a first projection distance of the distance on a first axis of the water area carrier 20 and a second projection distance of the distance on a second axis of the water area carrier 20, wherein the first axis is parallel to the roll axis of the water area carrier 20 and perpendicular to the second axis; and calculating the angular error based on the first projection distance and the second projection distance.

[0114] In some embodiments, the thruster 10 includes a steerable member, and determining the thrust direction of the target thrust required by the thruster 10 based on the angle error includes: determining a target steering position of the steerable member based on the angle error.

[0115] In some embodiments, the steerable member includes a propulsion device 11 in the propeller 10 .

[0116] In some embodiments, the propeller 10 includes a rudder blade and a propulsion device 11, and the steerable member includes the rudder blade.

[0117] In some embodiments, the steering stroke of the steerable member from a reference position to a target steering position is positively correlated with the angle error, and the reference position is the position where the axis of the thrust direction of the propeller passes through the center point of the water body 20.

[0118] In some embodiments, the target steering position is determined based on the angle error and predetermined steering parameters.

[0119] In some embodiments, the method also includes: calculating the distance error between the subsequent position and the target position; calculating the thrust magnitude of the target thrust based on the distance error; controlling the thruster 10 to generate a target thrust in the direction of the thrust, including: controlling the thruster 10 to generate a target thrust in the direction of the thrust and with a magnitude of the thrust magnitude.

[0120] In some embodiments, the thrust magnitude is positively correlated with the distance error.

[0121] In some embodiments, the thrust magnitude is determined based on the range error and a predetermined range parameter.

[0122] In some embodiments, the thrust magnitude of the target thrust is calculated based on the distance error, including: obtaining the moving speed of the water body carrier 20 at the subsequent position; calculating the speed error between the moving speed and the expected speed when the water body carrier reaches the target position, the expected speed being less than a speed threshold; and calculating the thrust magnitude of the target thrust based on the distance error and the speed error.

[0123] In some embodiments, the moving speed and the expected speed include the speed of the water vehicle 20 on a first axis, which is parallel to the rolling axis X of the water vehicle 20 .

[0124] In some embodiments, the moving speed is acquired based on the inertial measurement sensor 40 .

[0125] In some embodiments, the moving speed is obtained based on the inertial measurement sensor 40 and the global navigation satellite system 50 .

[0126] In some embodiments, obtaining the moving speed of the water carrier 20 at a subsequent position includes: calculating a first speed of the water carrier 20 on the first axis based on acceleration data output by the inertial measurement sensor 40; determining a second speed of the water carrier 20 on the first axis based on speed data output by the global navigation satellite system 50; and fusing the first speed and the second speed to obtain the moving speed of the water carrier 20 at the subsequent position.

[0127] In some embodiments, the thrust magnitude is positively correlated with the distance error; and / or the thrust magnitude is positively correlated with the speed error.

[0128] In some embodiments, the thrust magnitude is determined based on a speed error, a distance error, and a predetermined parameter, wherein the predetermined parameter includes at least one of a predetermined distance parameter or a predetermined speed parameter.

[0129] In some embodiments, controlling the thruster 10 to generate a target thrust in the thrust direction includes: determining a target operating parameter that matches the thrust magnitude of the target thrust based on a mapping relationship between the thrust magnitude of the thruster 10 and the operating parameters; controlling the thruster 10 to operate with the target operating parameter to generate a target thrust in the thrust direction and with a thrust magnitude that matches the target operating parameter.

[0130] In some embodiments, the thrust magnitude of the target thrust is a predetermined thrust value.

[0131] In some embodiments, controlling the thruster 10 to generate a target thrust in the thrust direction includes: determining a target operating parameter that matches a predetermined thrust value based on a mapping relationship between the thrust magnitude and operating parameters of the thruster 10; and controlling the thruster 10 to operate with the target operating parameter to generate a target thrust in the thrust direction and with a thrust magnitude of a predetermined thrust value.

[0132] In some embodiments, controlling the thruster 10 to generate the target thrust in the thrust direction includes: controlling the thruster 10 to operate with predetermined operating parameters to generate the target thrust in the thrust direction.

[0133] In some embodiments, the method further includes: when the distance error between the subsequent position of the water body 20 and the target position is within a predetermined error range, controlling the propeller 10 to stop generating thrust.

[0134] In some embodiments, the method is performed when a movable member of a control device 30 is not activated, the control device 30 being used to control the propeller 10 .

[0135] In some embodiments, the method is performed when the propeller 10 does not receive a steering instruction sent by the steering device 30 .

[0136] In some embodiments, the method is executed when the propeller 10 does not receive a throttle command sent by the control device 30 .

[0137] In some embodiments, the method also includes: during the period when the propeller 10 performs position keeping control, if the propeller 10 receives a movement instruction of the mobile water carrier 20 sent by the control device 30, then after the propeller 10 executes the movement instruction and the water carrier 20 meets the state maintenance condition, the position keeping control continues to be performed, and the control device 30 is used to control the propeller 10.

[0138] In some embodiments, the state maintaining condition includes that a deviation value of the position of the water area vehicle 20 after movement from the target position is less than a first deviation threshold.

[0139] In some embodiments, the position keeping control is continued, including: when the deviation value is between the second deviation threshold and the first deviation threshold, the position of the water area carrier 20 after movement is updated to the target position, and the position keeping control is continued, and the second deviation threshold is less than the first deviation threshold; when the deviation value is less than the second deviation threshold, the target position is kept unchanged, and the position keeping control is continued.

[0140] In some embodiments, when the deviation value reaches a first deviation threshold, the position keeping control is stopped.

[0141] In some embodiments, the method further includes: detecting whether there are other thrusters in working state on the water body carrier 20; if not, executing the step of calculating the target thrust required by the thruster 10.

[0142] The specific details of the above embodiment can also be found in the aforementioned method embodiment, which will not be repeated here.

[0143] The present application also provides a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the method for maintaining the position of a water body based on a single thruster as described in any embodiment of the present application is implemented. The computer-readable storage medium can be a phase change memory (PRAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), other types of random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory or other memory technology, a compact disc read-only memory (CD-ROM), a digital versatile disc (DVD) or other optical storage, a magnetic cassette, a magnetic tape magnetic disk storage or other magnetic storage device or any other non-transmission medium, which can be used to store information that can be accessed by a computing device.

[0144] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0145] The method and device provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for maintaining the position of a water body based on a single propeller, characterized in that: The method comprises: In response to the position keeping instruction, taking the current position of the water area carrier as the target position; Calculating the target thrust required by the propeller, wherein the target thrust is used to make the bow or stern of the water body face the target position and make the water body move forward or backward to maintain the target position; The thruster is controlled to generate the target thrust.

2. The method according to claim 1, characterized in that The thrust direction of the target thrust is used to make the target position fall on the first axis of the water area vehicle, and the first axis is parallel to the rolling axis of the water area vehicle.

3. The method according to claim 2, characterized in that The first axis coincides with the roll axis.

4. The method according to claim 1, characterized in that When the bow is closer to the target position than the stern, the target thrust is used to make the bow face the target position and make the water area vehicle move forward to maintain the target position.

5. The method according to claim 1, characterized in that When the stern is closer to the target position than the bow, the target thrust is used to make the stern face the target position and make the water area vehicle retreat to maintain the target position.

6. The method according to any one of claims 1 to 5, characterized in that: The calculating the target thrust required by the propeller comprises: Obtaining a subsequent position of the water body carrier; calculating an angular error between the subsequent position and the target position; A thrust direction of the target thrust is determined based on the angular error.

7. The method according to claim 6, characterized in that The position of the water body is obtained based on the global navigation satellite system.

8. The method according to claim 7, characterized in that The global navigation satellite system is arranged on the water body.

9. The method according to claim 7, characterized in that: The global navigation satellite system is arranged on the thruster.

10. The method according to claim 9, characterized in that Obtaining the location of the water area carrier includes: Obtaining the position of the propeller and the size of the water body; Based on the position of the propeller and the size of the water body, the position of the water body is determined.

11. The method according to claim 6, characterized in that The position of the water area carrier is obtained based on the global navigation satellite system and inertial measurement sensors.

12. The method according to claim 11, characterized in that Obtaining the location of the water area carrier includes: Obtaining the latest position data output by the global navigation satellite system; Calculating the moving distance of the water area carrier based on the acceleration data output by the inertial measurement sensor, the moving distance being the distance moved by the water area carrier in the period between the moment when the global navigation satellite system outputs the latest position data and the current moment; The position of the water area carrier is calculated based on the position data and the moving distance.

13. The method according to claim 7, characterized in that Obtaining the location of the water area carrier includes: Obtaining the latest position data output by the global navigation satellite system; Calculating the moving distance of the water body based on the moving speed of the propeller and the heading of the water body, the moving distance being the distance moved by the water body during the period between the moment when the global navigation satellite system outputs the latest position data and the current moment; The position of the water area carrier is calculated based on the position data and the moving distance.

14. The method according to claim 6, characterized in that The calculating the angular error between the subsequent position and the target position comprises: Obtaining a distance between the subsequent position and the target position; Obtaining a first projection distance of the distance on a first axis of the water area carrier and a second projection distance of the distance on a second axis of the water area carrier, wherein the first axis is parallel to the rolling axis of the water area carrier and perpendicular to the second axis; The angle error is calculated based on the first projection distance and the second projection distance.

15. The method according to claim 14, characterized in that The thruster includes a steerable member, and the determining the thrust direction of the target thrust based on the angle error includes: A target steering position of the steerable member is determined based on the angular error.

16. The method according to claim 15, characterized in that The steerable member comprises a propulsion device in the propeller.

17. The method according to claim 15, characterized in that The propeller comprises a rudder blade and a propulsion device, and the steerable member comprises the rudder blade.

18. The method according to claim 15, characterized in that The steering stroke of the steerable member from the reference position to the target steering position is positively correlated with the angle error, and the reference position is the position where the axis of the thrust direction of the propeller passes through the center point of the water area carrier.

19. The method according to claim 15, characterized in that The target steering position is determined based on the angular error and a predetermined steering parameter.

20. The method according to claim 6, characterized in that The calculating of the target thrust required by the propeller further includes: Calculating a distance error between the subsequent position and the target position; The thrust magnitude of the target thrust is calculated based on the distance error.

21. The method according to claim 20, characterized in that The thrust magnitude is positively correlated with the distance error.

22. The method according to claim 20, characterized in that The thrust magnitude is determined based on the distance error and a predetermined distance parameter.

23. The method according to claim 20, characterized in that The calculating the thrust magnitude of the target thrust based on the distance error comprises: Obtaining the moving speed of the water area carrier at the subsequent position; Calculating a speed error between the moving speed and an expected speed when the water area vehicle reaches the target position, the expected speed being less than a speed threshold; The thrust magnitude of the target thrust is calculated based on the distance error and the speed error.

24. The method according to claim 23, characterized in that The moving speed and the expected speed include a speed of the water body vehicle on a first axis, wherein the first axis is parallel to a roll axis of the water body vehicle.

25. The method according to claim 24, characterized in that The moving speed is obtained based on an inertial measurement sensor.

26. The method according to claim 24, characterized in that The moving speed is jointly acquired based on an inertial measurement sensor and a global navigation satellite system.

27. The method according to claim 26, characterized in that The obtaining of the moving speed of the water area carrier at the subsequent position includes: Calculating a first speed of the water area vehicle on the first axis based on the acceleration data output by the inertial measurement sensor; determining a second speed of the water body on the first axis based on speed data output by the global navigation satellite system; The first speed and the second speed are merged to obtain the moving speed of the water area carrier at the subsequent position.

28. The method according to claim 23, characterized in that The thrust magnitude is positively correlated with the distance error; and / or The thrust magnitude is positively correlated with the speed error.

29. The method according to claim 23, characterized in that The thrust magnitude is determined based on the speed error, the distance error and a predetermined parameter, wherein the predetermined parameter includes at least one of a predetermined distance parameter or a predetermined speed parameter.

30. The method according to claim 20, characterized in that The controlling the thruster to generate the target thrust comprises: Determining target operating parameters that match the thrust magnitude of the target thrust based on a mapping relationship between the thrust magnitude of the propeller and the operating parameters; The thruster is controlled to operate with the target operating parameters to generate the target thrust.

31. The method according to claim 6, characterized in that The thrust magnitude of the target thrust is a predetermined thrust value.

32. The method according to claim 31, characterized in that The controlling the thruster to generate the target thrust comprises: Determining a target operating parameter that matches the predetermined thrust value based on a mapping relationship between the thrust magnitude of the propeller and the operating parameter; The thruster is controlled to operate with the target operating parameters to generate the target thrust.

33. The method according to claim 6, characterized in that The controlling the thruster to generate the target thrust comprises: The thruster is controlled to operate with predetermined operating parameters to generate the target thrust.

34. The method according to claim 1, characterized in that The method further comprises: When the distance error between the subsequent position of the water area carrier and the target position is within a predetermined error range, the propeller is controlled to stop generating thrust.

35. The method according to claim 1, characterized in that The method is performed when a movable part of an actuation device is inactive, the actuation device being used to actuate the thruster.

36. The method according to claim 35, characterized in that The method is executed when the propeller does not receive a steering instruction sent by the control device.

37. The method according to claim 35, characterized in that The method is executed when the propeller does not receive a throttle command sent by the control device.

38. The method according to claim 1, characterized in that The method further comprises: During the period when the propeller performs position keeping control, if the propeller receives a movement instruction to move the water area carrier sent by a control device, then after the propeller executes the movement instruction and the water area carrier meets the state maintenance condition, the position keeping control continues to be performed, and the control device is used to control the propeller.

39. The method according to claim 38, characterized in that The state maintaining condition includes that a deviation value of the position of the water area carrier after movement from the target position is less than a first deviation threshold.

40. The method according to claim 39, characterized in that The continuing to perform the position keeping control comprises: When the deviation value is between a second deviation threshold and the first deviation threshold, updating the position of the water area carrier after movement to the target position, and continuing to perform the position keeping control, and the second deviation threshold is less than the first deviation threshold; When the deviation value is smaller than the second deviation threshold, the target position is kept unchanged and the position keeping control is continued.

41. The method according to claim 39, characterized in that When the deviation value reaches the first deviation threshold, the position keeping control is stopped.

42. The method according to claim 1, characterized in that The method further comprises: Detecting whether there are other propellers in working state on the carrier in the water area; If not present, the step of calculating the target thrust required by the thruster is performed.

43. A method for maintaining the position of a water body based on a single propeller, characterized in that: The method comprises: In response to the position keeping instruction, taking the current position of the water area carrier as the target position; Obtaining a subsequent position of the water body carrier; calculating an angular error between the subsequent position and the target position; Determining a thrust direction of a target thrust required by the thruster based on the angular error; The propeller is controlled to generate the target thrust in the thrust direction so as to keep the water area vehicle at the target position.

44. The method according to claim 43, characterized in that The position of the water body is obtained based on the global navigation satellite system.

45. The method according to claim 44, characterized in that The global navigation satellite system is arranged on the water body.

46. ​​The method according to claim 44, characterized in that The global navigation satellite system is arranged on the thruster.

47. The method according to claim 46, characterized in that Obtaining the location of the water area carrier includes: Obtaining the position of the propeller and the size of the water body; Based on the position of the propeller and the size of the water body, the position of the water body is determined.

48. The method according to claim 43, characterized in that The position of the water area carrier is obtained based on the global navigation satellite system and inertial measurement sensors.

49. The method according to claim 48, characterized in that Obtaining the location of the water area carrier includes: Obtaining the latest position data output by the global navigation satellite system; Calculating the moving distance of the water area carrier based on the acceleration data output by the inertial measurement sensor, the moving distance being the distance moved by the water area carrier in the period between the moment when the global navigation satellite system outputs the latest position data and the current moment; The position of the water area carrier is calculated based on the position data and the moving distance.

50. The method of claim 44, wherein: Obtaining the location of the water area carrier includes: Obtaining the latest position data output by the global navigation satellite system; Calculating the moving distance of the water body based on the moving speed of the propeller and the heading of the water body, the moving distance being the distance moved by the water body during the period between the moment when the global navigation satellite system outputs the latest position data and the current moment; The position of the water area carrier is calculated based on the position data and the moving distance.

51. The method according to claim 43, characterized in that The calculating the angular error between the subsequent position and the target position comprises: Obtaining the distance between the subsequent position and the target position; Obtaining a first projection distance of the distance on a first axis of the water area carrier and a second projection distance of the distance on a second axis of the water area carrier, wherein the first axis is parallel to the rolling axis of the water area carrier and perpendicular to the second axis; The angle error is calculated based on the first projection distance and the second projection distance.

52. The method according to claim 51, characterized in that The thruster includes a steerable member, and the determining the thrust direction of the target thrust required by the thruster based on the angle error includes: A target steering position of the steerable member is determined based on the angular error.

53. The method according to claim 52, characterized in that The steerable member comprises a propulsion device in the propeller.

54. The method according to claim 52, characterized in that The propeller comprises a rudder blade and a propulsion device, and the steerable member comprises the rudder blade.

55. The method according to claim 52, characterized in that The steering stroke of the steerable member from the reference position to the target steering position is positively correlated with the angle error, and the reference position is the position where the axis of the thrust direction of the propeller passes through the center point of the water area carrier.

56. The method according to claim 52, characterized in that The target steering position is determined based on the angular error and a predetermined steering parameter.

57. The method of claim 43, wherein: The method further comprises: Calculating a distance error between the subsequent position and the target position; Calculating the thrust magnitude of the target thrust based on the distance error; The controlling the propeller to generate the target thrust in the thrust direction includes: The thruster is controlled to generate the target thrust in the direction of the thrust and with a magnitude of the thrust.

58. The method according to claim 57, characterized in that The thrust magnitude is positively correlated with the distance error.

59. The method according to claim 57, characterized in that The thrust magnitude is determined based on the distance error and a predetermined distance parameter.

60. The method of claim 57, wherein: The calculating the thrust magnitude of the target thrust based on the distance error comprises: Obtaining the moving speed of the water area carrier at the subsequent position; Calculating a speed error between the moving speed and an expected speed when the water area vehicle reaches the target position, the expected speed being less than a speed threshold; The thrust magnitude of the target thrust is calculated based on the distance error and the speed error.

61. The method according to claim 60, characterized in that The moving speed and the expected speed include a speed of the water body vehicle on a first axis, wherein the first axis is parallel to a roll axis of the water body vehicle.

62. The method according to claim 61, characterized in that The moving speed is obtained based on an inertial measurement sensor.

63. The method according to claim 61, characterized in that The moving speed is jointly acquired based on an inertial measurement sensor and a global navigation satellite system.

64. The method according to claim 63, characterized in that The obtaining of the moving speed of the water area carrier at the subsequent position includes: Calculating a first speed of the water area vehicle on the first axis based on the acceleration data output by the inertial measurement sensor; determining a second speed of the water body on the first axis based on speed data output by the global navigation satellite system; The first speed and the second speed are merged to obtain the moving speed of the water area carrier at the subsequent position.

65. The method according to claim 60, characterized in that The thrust magnitude is positively correlated with the distance error; and / or The thrust magnitude is positively correlated with the speed error.

66. The method of claim 60, wherein: The thrust magnitude is determined based on the speed error, the distance error and a predetermined parameter, wherein the predetermined parameter includes at least one of a predetermined distance parameter or a predetermined speed parameter.

67. The method according to claim 57, characterized in that The controlling the propeller to generate the target thrust in the thrust direction includes: Determining target operating parameters that match the thrust magnitude of the target thrust based on a mapping relationship between the thrust magnitude of the propeller and the operating parameters; The propeller is controlled to operate with the target operating parameters to generate the target thrust having a direction that is the thrust direction and a thrust magnitude that matches the target operating parameters.

68. The method of claim 43, wherein: The thrust magnitude of the target thrust is a predetermined thrust value.

69. The method according to claim 68, characterized in that The controlling the propeller to generate the target thrust in the thrust direction includes: Determining a target operating parameter that matches the predetermined thrust value based on a mapping relationship between the thrust magnitude of the propeller and the operating parameter; The propeller is controlled to operate with the target operating parameters to generate the target thrust having a direction that is the thrust direction and a thrust magnitude that is the predetermined thrust value.

70. The method of claim 43, wherein: The controlling the propeller to generate the target thrust in the thrust direction includes: The thruster is controlled to operate with predetermined operating parameters to generate the target thrust in the thrust direction.

71. The method according to claim 43, characterized in that The method further comprises: When the distance error between the subsequent position of the water area carrier and the target position is within a predetermined error range, the propeller is controlled to stop generating thrust.

72. The method of claim 43, wherein: The method is performed when a movable part of an actuation device is inactive, the actuation device being used to actuate the thruster.

73. The method according to claim 72, characterized in that The method is executed when the propeller does not receive a steering instruction sent by the control device.

74. The method according to claim 72, characterized in that The method is executed when the propeller does not receive a throttle command sent by the control device.

75. The method of claim 43, wherein: The method further comprises: During the period when the propeller performs position keeping control, if the propeller receives a movement instruction to move the water area carrier sent by a control device, then after the propeller executes the movement instruction and the water area carrier meets the state maintenance condition, the position keeping control continues to be performed, and the control device is used to control the propeller.

76. The method according to claim 75, characterized in that The state maintaining condition includes that a deviation value of the position of the water area carrier after movement from the target position is less than a first deviation threshold.

77. The method according to claim 76, characterized in that The continuing to perform the position keeping control comprises: When the deviation value is between a second deviation threshold and the first deviation threshold, updating the position of the water area carrier after movement to the target position, and continuing to perform the position keeping control, and the second deviation threshold is less than the first deviation threshold; When the deviation value is smaller than the second deviation threshold, the target position is kept unchanged and the position keeping control is continued.

78. The method according to claim 76, characterized in that When the deviation value reaches the first deviation threshold, the position keeping control is stopped.

79. The method of claim 43, wherein: The method further comprises: Detecting whether there are other propellers in working state on the carrier in the water area; If not present, the step of calculating the target thrust required by the thruster is performed.

80. A computer-readable storage medium, characterized in that Computer instructions are stored thereon, and when the computer instructions are executed by a processor, the method for maintaining the position of a water body based on a single propeller as described in any one of claims 1 to 79 is implemented.

81. A propeller, characterized in that: The propeller comprises: Propulsion plant; and A processor, wherein the processor is electrically connected to the propulsion device, and the processor is used to execute the method for maintaining the position of a water body based on a single propeller as described in any one of claims 1 to 79.

82. A movable device in water area, characterized in that: The movable equipment in the water area includes: Water carriers; and The propeller as described in claim 81 is arranged on the water body carrier.

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