CN113120196A

CN113120196A - Motion control method and control system of underwater robot

Info

Publication number: CN113120196A
Application number: CN202110389597.3A
Authority: CN
Inventors: 王峥; 汤凯栾; 肖寅; 陈奕杉; 张斌斌; 刘思聪; 易娟
Original assignee: Southwest University of Science and Technology
Current assignee: Tsmc Shenzhen Technology Investment Co ltd; Southwest University of Science and Technology
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2021-07-16
Anticipated expiration: 2041-04-12
Also published as: CN113120196B

Abstract

The application discloses a motion control method and a motion control system of an underwater robot, wherein the underwater robot comprises a platform and a power device connected with the platform, the power device comprises at least three first propellers of which the propulsion directions are in the same propulsion plane, and the first propellers can change the magnitudes of the respective propulsion forces so that the resultant force of the propulsion forces is in the positive direction or the negative direction of any coordinate axis in the propulsion plane along a preset coordinate system; the method comprises the following steps: acquiring a translation direction and a translation speed of the underwater robot in a propulsion plane, wherein the translation direction and the translation speed are input by a user; calculating thrust required by the underwater robot in the translation direction according to the translation speed; carrying out vector conversion on the thrust according to included angles between the propelling directions of the at least three first propellers and a preset coordinate system to obtain propelling forces corresponding to the at least three first propellers; and controlling at least three first propellers to propel the underwater robot to move with corresponding propulsion force. The motion control method can simply and conveniently control the motion of the underwater robot.

Description

Motion control method and control system of underwater robot

Technical Field

The invention relates to the field of robots, in particular to a motion control method and a motion control system of an underwater robot.

Background

At present, an underwater robot widely replaces a human diver to complete various underwater tasks, such as underwater sampling, underwater operation and the like. The motion of the underwater robot is usually controlled by a user through a manipulator, and how to simplify the control of the translational motion as much as possible and further realize more complex motion is one of the problems to be improved or solved.

Disclosure of Invention

According to a first aspect, an embodiment discloses a motion control method of an underwater robot, the underwater robot comprises a platform and a power device connected with the platform, the power device comprises at least three first propellers with propulsion directions in the same propulsion plane, and the at least three first propellers can change the magnitude of respective propulsion forces to enable the resultant force of the propulsion forces to be positive or negative along any coordinate axis in the propulsion plane of a preset coordinate system;

the method comprises the following steps:

acquiring a translation direction and a translation speed of the underwater robot in a propulsion plane, wherein the translation direction is positive or negative of any coordinate axis of the preset coordinate system and is input by a user;

calculating thrust required by the underwater robot in the translation direction according to the translation speed;

performing vector conversion on the thrust according to included angles between the propelling directions of the at least three first propellers and a preset coordinate system to obtain propelling forces corresponding to the at least three first propellers;

and controlling the at least three first propellers to propel the underwater robot to move with corresponding propulsion force.

According to a second aspect, an embodiment discloses a motion control system of an underwater robot, the motion control system is used for controlling a power device connected with a platform of the underwater robot, the power device comprises at least three first propellers with propulsion directions in the same propulsion plane, and the at least three first propellers can change the magnitude of respective propulsion forces so that the resultant force of the propulsion forces is positive or negative along any coordinate axis in the propulsion plane of a preset coordinate system;

the motion control system includes:

the control system is used for receiving an instruction input by a user so as to obtain the translation direction and the translation speed of the underwater robot in a propulsion plane, wherein the translation direction and the translation speed are input by the user;

the processing system is used for calculating thrust required by the underwater robot in the translation direction according to the translation speed, and performing vector conversion on the thrust according to included angles between the propulsion directions of the at least three first propellers and a preset coordinate system to obtain the propulsion corresponding to the at least three first propellers;

and the driving system is used for driving the at least three first propellers to propel the underwater robot to move with corresponding propulsion force.

According to a third aspect, an embodiment discloses a computer readable storage medium having a program stored thereon, the program being executable by a processor to implement the method as described in the first aspect.

Through vector conversion in the above-mentioned embodiment, the user only needs input translation speed and translation direction, and the motion control system just can the size of the driving force of automatic control first propeller in order to realize corresponding motion, controls the simple easy learning of mode, and the low facilitate promotion of threshold.

Drawings

Fig. 1 is a schematic structural composition diagram of a motion control system of an underwater robot according to an embodiment;

FIG. 2 is a schematic structural component diagram of an embodiment of an underwater robot;

FIG. 3 is a schematic diagram of an embodiment of an underwater robot;

FIG. 4 is a schematic view of an embodiment of a translation of an underwater robot;

FIG. 5 is a schematic diagram of the elevating movement of an embodiment of the underwater robot;

FIG. 6 is a schematic diagram of the turning motion of an embodiment of the underwater robot;

FIG. 7 is a schematic diagram of the rotational motion of an embodiment of an underwater robot;

FIG. 8 is a flowchart of a method for controlling translation of an underwater robot according to an embodiment;

FIG. 9 is a flowchart of a method for controlling the lifting motion of the underwater robot according to an embodiment;

FIG. 10 is a flowchart of a method for controlling the turning motion of the underwater robot according to an embodiment;

FIG. 11 is a flowchart of a method for controlling the rotational motion of an underwater robot according to an embodiment;

100. a working device;

110. a jaw arrangement;

111. a finger base; 112. a jaw finger; 113. a software driving unit;

120. a robot arm main body;

200. a power plant;

210. a first propeller; 220. a second propeller; 230. rotating the propeller;

300. a motion control system;

310. a control system; 320. a processing system; 330. a drive system;

400. a platform.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. Also, the various steps or actions in the method descriptions may be transposed or transposed in order, as will be apparent to one of ordinary skill in the art. Thus, the various sequences in the specification and drawings are for the purpose of describing certain embodiments only and are not intended to imply a required sequence unless otherwise indicated where such sequence must be followed.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

The vector in any quadrant of the coordinate system can be synthesized by one vector on the horizontal axis and another vector on the vertical axis, the same also holds true for the above process, if the vector directions in different quadrants are defined, the vector on the horizontal axis or the vector on the vertical axis can be synthesized by projecting the vector on the above vector direction onto the horizontal axis or the vertical axis, and the vector conversion refers to the process.

The first embodiment is as follows:

referring to fig. 1, the present invention provides a motion control system 300 of an underwater robot, where the motion control system 300 is used to control a power device 200 of the underwater robot, so as to control the motion of the underwater robot, and the underwater robot in this embodiment can realize translation, up-down lifting, turning, rotation, and other motions in a propulsion plane, so as to meet the requirements of underwater operations. The following is a detailed description.

In order to better understand the working principle of the control system of the present embodiment, the underwater robot of the present embodiment will be described first. Referring to fig. 2, the underwater robot includes a working device 100, a power device 200, a motion control system 300, and a platform 400 for carrying the above components.

Platform 400 is the "skeleton" of the underwater robot, and the devices or apparatuses in the underwater robot are directly or indirectly mounted on platform 400, and the shape of platform 400 (referring to the projected shape of the top view) may be a triangle, such as an equilateral triangle or an isosceles triangle, or a quadrilateral, such as a parallelogram or a rectangle, or a disk. The platform 400 is illustrated as an equilateral triangle.

The working device 100 is a generic name of equipment or components required for the underwater robot to perform underwater operations. The following examples are given.

In some embodiments, as shown in FIG. 3, the working device 100 includes a robotic arm assembly, a camera device, and/or a sampling device. Wherein the robot assembly comprises a gripper apparatus 110 and a robot body 120, one side of the robot body 120 is connected to the bottom of the platform 400 for controlling the gripper apparatus 110 to grip an object located under the underwater robot, the other side of the robot body is connected to the gripper apparatus 110, and the gripper apparatus 110 comprises a finger base 111, at least two gripper fingers 112 and at least two soft drive units 113. The finger base 111 has a connecting portion for connecting with the robot arm main body 120 and a bearing portion. One end of the gripper finger 112 is hinged to the bearing portion of the finger base 111. Each gripper finger 112 is connected to at least one soft drive unit 113, and the soft drive unit 113 is used for communicating with a fluid source, and can be extended and folded under the action of fluid pressure so as to drive the gripper fingers 112 to rotate around the hinged joints of the gripper fingers and the base 111 of the finger root, thereby clamping or releasing the object.

The working device 100 drives the clamping jaw fingers 112 to move through the soft driving unit 113, so that the underwater objects can be grabbed or operated. Meanwhile, the soft driving unit 113 has strong adaptability to the environment and high working stability, and is suitable for underwater work. The clamping jaw device 110 is driven by a soft driving unit 113, which is beneficial to improving the adaptability of the underwater robot to complex environments and the working stability of the underwater robot.

The power plant 200 is used to power the movement of the underwater robot, and the power plant 200 includes three first propellers 210, three second propellers 220, and a rotary propeller 230. In other embodiments, the power plant 200 may also include more than three first propellers 210 and more than three second propellers 220. In one embodiment, the first propeller 210 and the second propeller 220 comprise at least one of a propeller and a shaftless pump jet propeller. In other embodiments, the first propeller 210 and the second propeller 220 may be any suitable type of propeller as long as the purpose of propulsion can be achieved.

As shown in fig. 4, the first thruster 210 is responsible for achieving translational movement of the underwater robot in the propulsion plane.

The above-mentioned thrust plane is a virtual plane, and in this embodiment corresponds to a plane parallel to the paper surface in fig. 4, or may be understood as a plane maintained parallel to the platform 400, and it is easily understood that when the platform 400 is turned, the thrust plane is also turned to be maintained parallel to the platform 400.

A Cartesian space rectangular coordinate system is preset in the propulsion plane, the X axis and the Y axis of the Cartesian space rectangular coordinate system are always located in the propulsion plane, and the Z axis is perpendicular to the propulsion plane. In this embodiment, the origin of the predetermined coordinate system is on the central axis of the platform 400, such that the Z-axis coincides with the central axis of the platform 400. In other embodiments, the origin of the preset coordinates may be at other locations.

The underwater robot has four translation directions in a propulsion plane, namely positive and negative directions of an X axis and positive and negative directions of a Y axis. The three first thrusters 210 are respectively mounted on three sides of the platform 400 and have a thrusting direction perpendicular to the three sides and all parallel to the thrusting plane, or just in the thrusting plane, the angle between the thrusting direction of each first thruster 210 and the adjacent coordinate axis is respectively 30 ° and 60 °, and the three thrusting directions are 120 ° with respect to each other. The three first thrusters 210 can propel the underwater robot to translate by changing the magnitude of the respective thrusting forces so that the resultant force of the thrusting forces is in any one of the four translation directions.

The second thruster 220 is responsible for lifting and turning the underwater robot.

The lifting of the underwater robot means that the underwater robot can be raised or lowered in a direction perpendicular to the propulsion plane. The second thruster 220 has a propulsion direction perpendicular to the propulsion plane, i.e. positive or negative along the Z-axis, so as to propel the underwater robot up or down. As shown in fig. 5, the three second thrusters 220 of the present embodiment are respectively installed at three corners of the platform 400, so that the platform 400 ascends or descends more smoothly, and when more than three second thrusters 220 are used, the more than three second thrusters may be arranged around the central axis of the platform 400 in view of stability. In other embodiments, only one or two propellers may be installed on the platform 400, if only the underwater robot is to be lifted.

The turning of the underwater robot means that the underwater robot can rotate clockwise or counterclockwise around the X-axis or the Y-axis of the preset coordinate system. As shown in fig. 6, of the three second propellers 220, one second propeller 220 is in the region of the positive half axis of the Y-axis, and the other two second propellers 220 are in the region of the negative half axis of the Y-axis, in other words, one second propeller 220 is in the region of the positive half axis of the X-axis, the other second propeller 220 is in the region of the negative half axis of the X-axis, and the other second propeller 220 is on the Y-axis. When the propulsion directions of the second propellers 220 in the positive half shaft area and the negative half shaft area are opposite in the same coordinate axis, the underwater robot can turn around the coordinate axis.

As shown in fig. 7, the rotary propeller 230 is responsible for realizing the rotation of the underwater robot around the central axis thereof.

The rotary propeller 230 can rotate clockwise or counterclockwise, for example, the rotary propeller 230 is a rotary impeller. The rotation center line of the rotary pusher 230 coincides with the center axis of the platform 400. When the rotary propeller 230 rotates, a driving force can be provided for the rotation of the platform 400 about its central axis.

In other embodiments, if the underwater robot only needs to complete a certain mode of movement, only the propeller corresponding to the underwater robot can be installed.

Referring to fig. 1, the control system 310 is configured to receive an instruction input by a user, so as to obtain at least one of a translation direction and a translation speed, a lifting direction and a lifting speed, a turning direction and a turning direction, a rotation direction and a rotation speed of the underwater robot in a propulsion plane, where the underwater robot is input by the user, and after obtaining the information, the information may be sent to the processing system 320 for processing by the processing system 320.

In some embodiments, the SOC (System on Chip) of the control System 310 employs an ARM Cortex a53 Quad-core, and the control System further includes a 3DX manipulator and an image analysis System, where the 3DX manipulator is a six-axis manipulator capable of analyzing the operation of the user into motion information in six degrees of freedom and transmitting the motion information to the SOC, and the motions in the six degrees of freedom are respectively a movement along an X-axis, a Y-axis, and a Z-axis of a preset coordinate System and a rotation around the X-axis, the Y-axis, and the Z-axis. The SOC packages the motion information and then transmits the motion information to the processing system 320 via the ethernet, and the SOC may further display the image, the visual 3DX control data, the attitude, depth, battery level, and other information on the screen of the 3DX controller for the user to obtain the information.

In other embodiments, the SOC of the operating system 310 may also be implemented by other chips that can meet the requirement, and similarly, the controller may also be implemented by various types of handles or joysticks, etc. besides the 3DX controller, and the communication between the operating system and the processing system 320 may also be implemented by other types of high-speed low-latency cable communication, besides ethernet transmission.

The processing system 320 is configured to analyze the received motion information to obtain the power required to implement the corresponding motion, and the processing system 320 may process data by using ARM Cortex-M7 as a core. The following is a detailed description.

In some embodiments, as shown in fig. 4, the motion information input by the user through the manipulation system 310 is moving along the Y-axis at the speed of V1, and the processing system 320 can calculate the thrust force F1 in the Y-axis required by the current environment according to the motion information, where F1 is a vector in the preset coordinate system, and the vector can be represented as (X, Y) in the preset coordinate system. Since the angles between the three first propellers 210 and the Y axis and the X axis are known, the vector (X, Y) can be converted into three vectors at 120 ° to each other, which are respectively denoted as vectors a, b, and c, and the corresponding coordinates are respectively (a1, b1, c1), (a2, b2, c2), (a3, b3, c 3). The three vectors a, b and c are equal to the vector F1 in magnitude and direction, and the three vectors a, b and c are the propulsion forces required to be generated by the three first propellers 210.

The translation of the underwater robot in other directions in the propulsion plane is similar to the above process, and is not described herein.

In some embodiments, the motion information input by the user through the manipulation system 310 is a positive movement along the Z-axis at the velocity of V2, i.e., the underwater robot ascends. The processing system 320 may calculate the lifting force F2 on the Z axis required by the current environment according to the motion information, and may calculate the lifting propulsion force required by the three second thrusters 220 according to F2, for example, each lifting propulsion force is one third of the lifting force F2.

The descending process of the underwater robot is similar to the ascending process, and is not described in detail herein.

In some embodiments, as shown in FIG. 6, the motion information entered by the user via the manipulation system 310 is rotated clockwise (as viewed from the negative half of the Y-axis toward the positive half of the Y-axis) about the Y-axis at an angular velocity of W1. Based on the axis of rotation being the Y-axis, the processing system 320 may derive the direction of propulsion for the second propeller 220 in the region of the positive X-axis and the second propeller 220 in the region of the negative X-axis. The processing system 320 may calculate the magnitude of the turning force F3 required by the current environment according to the motion information, and assign the turning propulsion force of the second propellers 220 on both sides of the Y-axis according to F3.

The process of the underwater robot rotating around other coordinate axes is similar to the above process, and is not described herein.

In some embodiments, the motion information entered by the user through the manipulation system 310 is rotated clockwise (as viewed from the negative half of the Z axis toward the positive half of the Y axis) about the Z axis at an angular velocity of W2. The processing system 320 may calculate the rotation speed required to rotate the propeller 230 in the current environment according to the motion information.

After the processing system 320 solves the power required for realizing the corresponding motion, the processing system 320 sends a control command to the driving system 330, and the driving system 330 drives each propeller to work with the solved propulsion force or speed, thereby realizing the motion of the underwater robot. The driving system 330 may include components such as a dc brushless motor, a dc brushless motor controller, a hydraulic pump, a relay, a hydraulic valve, and a photo-coupled solenoid valve controller, which cooperate to achieve the desired functions of the driving system 330.

The underwater robot also comprises other necessary devices or equipment, for example the underwater robot also comprises a built-in power supply, sensors for sensing the surroundings (e.g. IMU, depth or pressure sensors, to determine the propulsion required at a certain speed of the current environment).

Example two:

on the basis of the motion control system 300 of the underwater robot disclosed in the first embodiment, the present embodiment discloses a motion control method of the underwater robot. The control method is mainly applied to the underwater robot shown in fig. 2.

As shown in fig. 8, when the user controls the underwater robot to perform translation, the motion control method includes:

and step 1000, acquiring the translation direction and the translation speed of the underwater robot in a propulsion plane, wherein the translation direction and the translation speed are input by a user. The translation direction is positive or negative of any coordinate axis of a preset coordinate system. I.e., positive and negative X-axis and positive and negative Y-axis.

And 1100, calculating thrust required by the underwater robot in the translation direction according to the translation speed. The underwater robot receives different pressures at different underwater depths, so the thrust required by the same speed is different, the current depth can be acquired according to the depth sensor on the underwater robot, and then the required thrust is acquired, for example, a user wants to make the underwater robot move forward along the Y axis at the speed of V1, the thrust F1 on the Y axis required by the current environment can be calculated according to the motion information, the F1 is a vector in the preset coordinate system, and the vector can be expressed as (X, Y) in the preset coordinate system.

Step 1200, performing vector conversion on the thrust according to included angles between the propelling directions of the three first propellers 210 and a preset coordinate system to obtain the propelling forces corresponding to the three first propellers 210.

In this embodiment, the angle between the propulsion directions of the adjacent first propellers 210 is 120 °, and the angles between the respective Y-axis and X-axis of the three first propellers 210 are known, so that the vectors (X, Y) can be converted into three vectors each at 120 °, which are respectively denoted as vectors a, b, and c, and the corresponding coordinates are (a1, b1, c1), (a2, b2, c2), (a3, b3, c 3). The three vectors a, b and c are equal to the vector F1 in magnitude and direction, and the three vectors a, b and c are the propulsion forces required to be generated by the three first propellers 210.

And 1300, controlling the three first propellers 210 to propel the underwater robot with corresponding propulsion.

As shown in fig. 9, when the user controls the underwater robot to ascend and descend, the motion control method includes:

and 2000, acquiring the lifting direction and the lifting speed of the underwater robot, which are input by a user and are vertical to the propulsion plane.

For example, the user wants to control the underwater robot to move forward along the Z-axis at the speed of V2, that is, the underwater robot ascends.

And step 2100, controlling the propelling directions of the three second propellers 220 according to the lifting direction.

The propulsion direction of the three second propellers 220 is the same as the lifting direction of the underwater robot.

And 2200, calculating the lifting force required by the underwater robot according to the lifting speed.

And 2300, decomposing the lifting force to obtain the lifting propelling force corresponding to the second propeller.

For example, the lifting force F2 on the Z axis required by the current environment is calculated, and the lifting propulsion force required by the three second thrusters 220 is one third of the lifting force F2.

And 2400, controlling the three second thrusters 220 to propel the underwater robot with the corresponding lifting propelling force.

As shown in fig. 10, when the user controls the underwater robot to turn, the motion control method includes:

step 3000, acquiring the turning direction and turning speed of the underwater robot input by a user. The turning direction is clockwise or anticlockwise rotation around any coordinate axis of a preset coordinate system.

For example, the user wants to control the underwater robot to rotate clockwise (as viewed from the negative half axis of the Y-axis toward the positive half axis of the Y-axis) about the Y-axis at an angular velocity of W1 by operation.

And 3100, determining a coordinate axis serving as a rotating axis in a preset coordinate system according to the overturning direction.

For example, the Y axis is set as the rotation axis by the user operation.

Step 3200, calculating the turning propelling forces corresponding to the second propellers 220 distributed on both sides of the rotation axis according to the turning speed.

In this embodiment, the rotation axis is the Y axis, and there is one second thruster 220 on each side of the Y axis, and if the turning force required to reach the turning speed W1 under the current circumstances is F3, the turning thrust of the second thrusters 220 on each side of the Y axis is distributed (vector resolved) according to F3.

And 3300, controlling the second propellers 220 distributed on both sides of the rotating shaft to propel the underwater robot with corresponding overturning propulsive force.

As shown in fig. 11, when the user controls the rotation of the underwater robot, the method includes:

and step 4000, acquiring the rotation direction and the rotation speed of the underwater robot input by a user. The rotation direction is clockwise or counterclockwise around the central axis of the platform 400, i.e. clockwise or counterclockwise around the Z-axis of the preset coordinate system in this embodiment. For example, the user wants to control the underwater robot to rotate clockwise (as viewed from the negative half of the Z axis toward the positive half of the Y axis) about the Z axis at an angular velocity of W2 by operation.

Step 4100, calculating a rotation speed corresponding to the rotary propeller 230 according to the rotation speed.

When the rotary thruster 230 is fixedly connected to the platform 400, the rotation speed of the rotary thruster 230 may be similar to the rotation speed of the underwater robot around the Z-axis.

And step 4200, controlling the rotary propeller 230 to rotate in the rotation direction at the corresponding rotation speed to drive the underwater robot to rotate.

It should be noted that the above motions may be combined, for example, a user may control the underwater robot to translate and turn, or translate and rotate, so as to perform more complex motions.

In the embodiment, parameters input by a user can be quickly converted into the thrust of the first propeller through vector conversion, so that the translation of the underwater robot is realized, and the underwater robot can be conveniently controlled to complete various complex motions by matching with the second propeller and the rotary propeller.

Those skilled in the art will appreciate that all or part of the functions of the various methods in the above embodiments may be implemented by hardware, or may be implemented by computer programs. When all or part of the functions of the above embodiments are implemented by a computer program, the program may be stored in a computer-readable storage medium, and the storage medium may include: a read only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, etc., and the program is executed by a computer to realize the above functions. For example, the program may be stored in a memory of the device, and when the program in the memory is executed by the processor, all or part of the functions described above may be implemented. In addition, when all or part of the functions in the above embodiments are implemented by a computer program, the program may be stored in a storage medium such as a server, another computer, a magnetic disk, an optical disk, a flash disk, or a removable hard disk, and may be downloaded or copied to a memory of a local device, or may be version-updated in a system of the local device, and when the program in the memory is executed by a processor, all or part of the functions in the above embodiments may be implemented.

The present invention has been described in terms of specific examples, which are provided to aid understanding of the invention and are not intended to be limiting. For a person skilled in the art to which the invention pertains, several simple deductions, modifications or substitutions may be made according to the idea of the invention.

Claims

1. A motion control method of an underwater robot, characterized in that the underwater robot comprises a platform (400) and a power device (200) connected with the platform (400), the power device (200) comprises at least three first propellers (210) with propelling directions in the same propelling plane, and the at least three first propellers (210) can change the magnitude of respective propelling forces to enable the resultant force of the propelling forces to be positive or negative along any coordinate axis in the propelling plane of a preset coordinate system;

the method comprises the following steps:

performing vector conversion on the thrust according to included angles between the propelling directions of the at least three first propellers (210) and a preset coordinate system to obtain propelling forces corresponding to the at least three first propellers (210);

controlling the at least three first propellers (210) to propel the underwater robot to move with corresponding propulsion force.

2. The method of claim 1, wherein the platform (400) is triangular, quadrilateral or circular in shape.

3. The method of claim 1, wherein the power plant (200) further comprises at least one second propeller (220), a propulsion direction of the second propeller (220) being perpendicular to the propulsion plane, the method further comprising:

acquiring a lifting direction and a lifting speed of the underwater robot perpendicular to the propulsion plane, wherein the lifting direction and the lifting speed are input by a user;

controlling a propulsion direction of the at least one second thruster (220) in dependence of the lifting direction;

calculating the lifting force required by the underwater robot according to the lifting speed;

decomposing the lifting force to obtain a lifting propulsion force corresponding to the at least one second propeller (220);

controlling the at least one second thruster (220) to propel the underwater robot to move with a corresponding lifting propulsion force.

4. The method of claim 3, wherein the predetermined coordinate system has an origin on a central axis of the platform (400), and wherein the predetermined coordinate system has at least one second thruster (220) distributed in both positive and negative half-axis regions of any one coordinate axis in a thrust plane, the method further comprising:

acquiring the turning direction and the turning speed of the underwater robot input by a user, wherein the turning direction is clockwise or anticlockwise rotated around any coordinate axis of the preset coordinate system;

determining a coordinate axis serving as a rotating axis in a preset coordinate system according to the turning direction;

calculating the turning propelling force corresponding to the second propellers (220) distributed on two sides of the rotating shaft according to the turning speed;

and controlling second propellers (220) distributed on two sides of the rotating shaft to propel the underwater robot to move with corresponding overturning propelling force.

5. The method according to any one of claims 1 to 4, wherein the power plant (200) further comprises a rotary thruster (230) rotatable clockwise or anticlockwise, the rotation centerline of the rotary thruster (230) coinciding with the central axis of the platform (400), the central axis of the platform (400) being perpendicular to the plane of propulsion, the method further comprising:

acquiring the rotation direction and the rotation speed of the underwater robot input by a user, wherein the rotation direction is clockwise rotation or anticlockwise rotation around the central axis of the platform (400);

according to the rotating speed, calculating to obtain the self-rotating speed corresponding to the rotating propeller (230);

and controlling the rotary propeller (230) to rotate along the rotation direction at a corresponding rotation speed so as to drive the underwater robot to rotate.

6. A motion control system of an underwater robot, characterized in that the motion control system (300) is used for controlling a power device (200) connected with a platform (400) of the underwater robot, the power device (200) comprises at least three first propellers (210) with propelling directions in the same propelling plane, and the at least three first propellers (210) can change the magnitude of each propelling force to enable the resultant force of the propelling forces to be positive or negative along any coordinate axis in the propelling plane of a preset coordinate system;

the motion control system (300) comprises:

the control system (310) is used for receiving an instruction input by a user so as to obtain the translation direction and the translation speed of the underwater robot in a propulsion plane, wherein the translation direction and the translation speed are input by the user;

the processing system (320) is used for calculating thrust required by the underwater robot in the translation direction according to the translation speed, and performing vector conversion on the thrust according to included angles between the propulsion directions of the at least three first propellers (210) and a preset coordinate system to obtain propulsion corresponding to the at least three first propellers (210);

a driving system (330) for driving the at least three first propellers (210) to propel the underwater robot to move with corresponding propulsion forces.

7. The motion control system according to claim 6, wherein the power plant (200) further comprises at least one second thruster (220), a propulsion direction of the second thruster (220) being perpendicular to the propulsion plane, the steering system (310) further being adapted to obtain user input of a lifting direction and a lifting speed of the underwater robot perpendicular to the propulsion plane;

the processing system (320) is further configured to control a propulsion direction of the at least one second thruster (220) according to the lifting direction, calculate a lifting force required by the underwater robot according to the lifting speed, and decompose the lifting force to obtain a lifting propulsion force corresponding to the at least one second thruster (220)

The driving system (330) is also used for driving the at least one second propeller (220) to propel the underwater robot to move with corresponding lifting propelling force.

8. The motion control system according to claim 7, wherein the origin of the predetermined coordinate system is on a central axis of the platform (400), and the predetermined coordinate system has at least one second propeller (220) distributed in both a positive half-axis region and a negative half-axis region of any one coordinate axis in a propulsion plane;

the control system (310) is further configured to acquire a turning direction and a turning speed of the underwater robot, which are input by a user, wherein the turning direction is clockwise or counterclockwise around any coordinate axis of the preset coordinate system;

the processing system (320) is further used for determining a coordinate axis serving as a rotating shaft in a preset coordinate system according to the overturning direction, and calculating overturning propelling forces corresponding to second propellers (220) distributed on two sides of the rotating shaft according to the overturning speed;

the driving system (330) is also used for driving second propellers (220) distributed on two sides of the rotating shaft to propel the underwater robot to move with corresponding overturning propelling force.

9. The motion control system according to any one of claims 6 to 8, characterized in that the power plant (200) further comprises a rotary thruster (230) capable of rotating clockwise or counterclockwise, the rotation centerline of the rotary thruster (230) coinciding with the central axis of the platform (400), the central axis of the platform (400) being perpendicular to the plane of propulsion;

the control system (310) is further used for acquiring a rotation direction and a rotation speed of the underwater robot input by a user, wherein the rotation direction is clockwise rotation or anticlockwise rotation around the central axis of the platform (400);

the processing system (320) is further used for calculating and obtaining a self-rotation speed corresponding to the rotary propeller (230) according to the rotation speed;

the driving system (330) is further configured to drive the rotary propeller (230) to rotate in the rotation direction at a corresponding rotation speed, so as to drive the underwater robot to rotate.

10. A computer-readable storage medium, characterized in that the medium has stored thereon a program which is executable by a processor to implement the method according to any one of claims 1-5.