Water surface omni-directional swimming robot and motion control method thereof

Abstract

The invention discloses a water surface omni-directional swimming robot. The water surface omni-directional swimming robot comprises a robot body and two swimming feet connected to the robot body. Wherein one of the two swimming feet is controlled to swing, and the other one of the two swimming feet is controlled not to swing, so that the water surface omnidirectional swimming robot moves in the plane where the robot body is located and moves in the direction of the other one of the two swimming feet; the two swimming feet are controlled to swing synchronously, so that the water surface omni-directional swimming robot moves along the normal square of the plane where the robot body is located. The invention further discloses a motion control method of the water surface omni-directional swimming robot. The invention further discloses a swimming robot with the swimming foot and a control method of the swimming robot. The water surface omni-directional swimming robot can move omni-directionally only by using the two multi-passive-joint propellers, and the number of the propellers is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and more specifically, relates to an omnidirectional surface swimming robot and its motion control method. Background Art

[0002] Traditional surface swimming robots use devices such as propellers or water jet thrusters for propulsion, and the motion of these devices is usually restricted in a specific direction. While omnidirectional surface swimming robots use devices such as omnidirectional thrusters and underwater electric thrusters (such as ring thrusters or turbine thrusters), which can achieve multi-dimensional free movement.

[0003] Existing omnidirectional surface swimming robots usually need to use three (or more) propellers (i.e., thrusters). By designing their layout on the swimming robot, each propeller provides propulsion force in the corresponding direction, thereby achieving omnidirectional movement in a plane. In addition, this propulsion method using propellers can provide a large propulsion force, enabling the swimming robot to obtain a high swimming speed. However, it also makes the turning radius of the swimming robot large, with poor maneuverability, and at the same time has the disadvantages of low efficiency and high noise. Summary of the Invention

[0004] In order to solve the above technical problems existing in the prior art, the present invention provides an omnidirectional surface swimming robot and its motion control method that can reduce the number of thrusters, improve maneuverability, improve efficiency, and reduce noise.

[0005] According to one aspect of the present invention, there is provided an omnidirectional surface swimming robot, which includes a robot body and two swimming feet connected to the robot body. Among them, by controlling one of the two swimming feet to swing and controlling the other of the two swimming feet not to swing, the omnidirectional surface swimming robot moves in the plane where the robot body is located and moves in the direction of the other of the two swimming feet. By controlling the two swimming feet to swing synchronously, the omnidirectional surface swimming robot moves along the normal direction of the plane where the robot body is located.

[0006] In an example of the omnidirectional surface swimming robot provided in the above aspect, the robot body is in a cylindrical shape, the two swimming feet are located in the same plane, and the distance between the installation positions of the two swimming feet on the robot body is the diameter of the robot body.

[0007] In an example of the omnidirectional surface swimming robot provided in the above aspect, the swimming foot includes a waterproof servo and a multi-passive joint thruster. The waterproof servo is installed on the robot body, and the multi-passive joint thruster is connected to the steering wheel of the waterproof servo.

[0008] In an example of the omnidirectional swimming robot on the water surface provided in the above aspect, the multi-passive joint thruster includes a plurality of rigid sheets. The plurality of rigid sheets are arranged at intervals, and two adjacent rigid sheets are connected by a flexible member. The rigid sheet connected to the waterproof servo motor among the plurality of rigid sheets is connected to the steering wheel of the waterproof servo motor through a rigid link.

[0009] In an example of the omnidirectional swimming robot on the water surface provided in the above aspect, the flexible member is made of spring steel.

[0010] In an example of the omnidirectional swimming robot on the water surface provided in the above aspect, an inertial measurement unit is provided on each of the other rigid sheets except the rigid sheet connected to the waterproof servo motor among the plurality of rigid sheets.

[0011] In an example of the omnidirectional swimming robot on the water surface provided in the above aspect, a central pattern generator is provided on each of the other rigid sheets except the rigid sheet connected to the waterproof servo motor among the plurality of rigid sheets.

[0012] In an example of the omnidirectional swimming robot on the water surface provided in the above aspect, the robot body includes a bottom shell and an upper shell, and the bottom shell and the upper shell are fixedly combined with each other through a rabbet structure.

[0013] In an example of the omnidirectional swimming robot on the water surface provided in the above aspect, sealant is provided at the joint gap between the bottom shell and the upper shell.

[0014] According to another aspect of the present invention, there is also provided a motion control method for the above omnidirectional swimming robot on the water surface, which includes: by controlling one of the two swimming feet to swing and controlling the other of the two swimming feet not to swing, enabling the omnidirectional swimming robot to move in the plane where the robot body is located and move in the direction of the other of the two swimming feet; by controlling the two swimming feet to swing synchronously, enabling the omnidirectional swimming robot to move along the normal direction of the plane where the robot body is located.

[0015] Beneficial effects: The omnidirectional swimming robot of the present invention can perform omnidirectional movement only using two multi-passive joint thrusters, reducing the number of thrusters. Further, the omnidirectional swimming robot of the present invention has a small turning radius while obtaining a high swimming speed, thus improving the maneuverability, and at the same time, it also has the advantages of high efficiency and low noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Through the following description in conjunction with the drawings, the above and other aspects, features and advantages of the embodiments of the present invention will become clearer. In the drawings:

[0017] Figure 1Is a three-dimensional schematic diagram of an omnidirectional swimming robot on the water surface according to an embodiment of the present invention;

[0018] Figure 2 Is a cross-sectional schematic diagram of the robot body of an omnidirectional swimming robot on the water surface according to an embodiment of the present invention;

[0019] Figure 3 Is a structural schematic diagram of a multi-passive joint thruster according to an embodiment of the present invention;

[0020] Figure 4 Is a schematic diagram of an omnidirectional swimming robot on the water surface performing omnidirectional movement according to an embodiment of the present invention. Detailed implementation manners

[0021] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different forms, and the present invention should not be construed as being limited to the specific embodiments set forth herein. On the contrary, these embodiments are provided to explain the principles of the present invention and its practical applications, so that those skilled in the art can understand various embodiments of the present invention and various modifications suitable for specific intended applications.

[0022] As used herein, the term "comprising" and its variants denote open terms, meaning "including but not limited to". Terms such as "based on", "according to" etc. mean "at least partially based on", "at least partially according to". The term "one embodiment" and "an embodiment" mean "at least one embodiment". The term "another embodiment" means "at least one other embodiment". Terms such as "first", "second" etc. may refer to different or the same objects. Other definitions may be included below, whether explicit or implicit. Unless explicitly specified in the context, the definition of a term is consistent throughout the specification.

[0023] Figure 1 Is a three-dimensional schematic diagram of an omnidirectional swimming robot on the water surface according to an embodiment of the present invention. Figure 2 Is a cross-sectional schematic diagram of the robot body of an omnidirectional swimming robot on the water surface according to an embodiment of the present invention.

[0024] Refer to Figure 1 And Figure 2 According to an embodiment of the present invention, the swimming robot includes an upper shell 1, a waterproof servo 2, a multi-passive joint thruster 9, a switch 4, and a bottom shell 5.

[0025] The upper shell 1 and the bottom shell 5 are assembled and combined with each other through a rabbet structure 8 to form a receiving space. Further, a sealant is provided at the joint gap between the upper shell 1 and the bottom shell 5 to achieve sealing. Electronic components such as a control board, a wireless communication module, and a lithium battery are disposed in the receiving space, and these electronic components are not marked in the figure. The switch 4 is disposed on the bottom shell 5 and is electrically connected to the control board through a circuit. Therefore, the upper shell 1, the switch 4, the bottom shell 5, and the electronic components in the receiving space constitute the robot body.

[0026] A waterproof servo 2 and a multi-passive joint thruster 9 form a swimming leg. Two swimming legs are connected to the robot body. Specifically, by controlling one of the two swimming legs to swing and controlling the other of the two swimming legs not to swing, the omnidirectional swimming robot on the water surface moves in the plane where the robot body is located and moves in the direction of the other of the two swimming legs; by controlling the two swimming legs to swing synchronously, the omnidirectional swimming robot on the water surface moves along the normal direction of the plane where the robot body is located.

[0027] In this embodiment, the robot body is in a cylindrical shape, the two swimming legs are located in the same plane, and the distance between the mounting positions of the two swimming legs on the robot body is the diameter of the robot body. That is to say, the two swimming legs are symmetrically mounted on both sides of the robot body at 180°.

[0028] In this embodiment, the waterproof servo 2 is mounted on the bottom shell 5, and the multi-passive joint thruster 9 is connected to the steering wheel of the waterproof servo 2. Further, the multi-passive joint thruster 9 is connected to the steering wheel of the waterproof servo 2 through a rigid link 3. In this embodiment, the structures of the two swimming legs are the same.

[0029] Figure 3 It is a schematic structural diagram of a multi-passive joint thruster according to an embodiment of the present invention.

[0030] Referring to Figure 1 and Figure 3 , the multi-passive joint thruster 9 according to the embodiment of the present invention includes three rigid sheets 91, which are arranged in a line at intervals, and two adjacent rigid sheets 91 are connected by a flexible member 92. In this embodiment, the rigid sheet 91 closest to the waterproof servo 2 is connected to the steering wheel 21 of the waterproof servo 2 through a rigid link 3. Further, the rigid sheet 91 closest to the waterproof servo 2 is integrally formed with the rigid link 3. In addition, the flexible member 92 is made of spring steel.

[0031] In addition, an inertial measurement unit 6 is respectively provided on each of the other two rigid sheets of the three rigid sheets 91 except the rigid sheet 91 closest to the waterproof servo 2. The inertial measurement unit 6 passes through a wire hole 7 (such as Figure 1As shown in the figure, the circuit is introduced onto the control board within the accommodation space to achieve the measurement of the deformation angle of the multi-passive joint thruster 9.

[0032] Furthermore, on each of the two rigid sheets among the three rigid sheets 91 except for the rigid sheet 91 closest to the distance waterproof servo 2, a central pattern generator (not labeled in the figure) is provided.

[0033] It should be noted that the number of rigid sheets 91 included in the multi-passive joint thruster 9 of the present invention is not limited to three and can be increased or decreased according to needs.

[0034] In order to enable the surface omnidirectional swimming robot to achieve omnidirectional movement on the water surface, the motion control of the central pattern generator (CPG) is described as follows:

[0035]

[0036] It should be noted that the subscript "l" in the second and third formulas above is "i". The parameter representations of each symbol are shown in the following table:

[0037]

[0038] Figure 4 is a schematic diagram of the omnidirectional movement of the surface omnidirectional swimming robot according to an embodiment of the present invention. For ease of description, in Figure 4 the swimming feet located on the left side of the robot body are named left swimming feet, and the swimming feet located on the right side of the robot body are named right swimming feet.

[0039] Refer to Figure 4 , imitate the symmetric swing of the fish tail fin (only one waterproof servo is enabled) to achieve the left and right movement of the surface omnidirectional swimming robot, and imitate the asymmetric rowing motion of the fish pectoral fin (both waterproof servos are enabled, and the time taken for the two swimming feet to swing down and up is different) to achieve the up and down movement. Specifically, when the expected amplitude of the swing of the right waterproof servo is 0 and the proportion of the time taken for the left waterproof servo to swing down and up is the same (time asymmetry coefficient = 0.5), the left waterproof servo drives the left multi-passive joint thruster 9 to swing, causing the surface omnidirectional swimming robot to move to the right. For a similar parameter design, when the expected amplitude of the swing of the left waterproof servo is 0 and the proportion of the time taken for the right waterproof servo to swing down and up is the same (time asymmetry coefficient = 0.5), the right waterproof servo drives the right multi-passive joint thruster 9 to swing, causing the surface omnidirectional swimming robot to move to the left.

[0040] When two waterproof servos are enabled simultaneously, the two multi-passive joint thrusters 9 swing synchronously, and the downward swing time is short while the upward swing time is long (time asymmetry coefficient = 0.75). At this time, the lateral forces of the surface omnidirectional swimming robot in the left and right directions are cancelled out. Due to the different swing speeds in the up and down directions, the surface omnidirectional swimming robot obtains an upward net thrust and thus moves upward. With a similar parameter design, when two waterproof servos are enabled simultaneously, the two multi-passive joint thrusters 9 swing synchronously, and the upward swing time is short while the downward swing time is long (time asymmetry coefficient = 0.25). At this time, the lateral forces of the surface omnidirectional swimming robot in the left and right directions are cancelled out. Due to the different swing speeds in the up and down directions, the surface omnidirectional swimming robot obtains a downward net thrust and thus moves downward.

[0041] In summary, the surface omnidirectional swimming robot according to the embodiment of the present invention can perform omnidirectional movement only using two multi-passive joint thrusters, reducing the number of thrusters. Further, the surface omnidirectional swimming robot according to the embodiment of the present invention has a small turning radius while obtaining a high swimming speed, thus improving the maneuverability. At the same time, it also has the advantages of high efficiency and low noise.

[0042] The optional implementation manners of the embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation manners. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

Claims

1. An omnidirectional swimming robot for water surface, characterized in that, The all-directional surface swimming robot includes a robot body and two swimming legs connected to the robot body; Among them, by controlling one of the two swimming legs to swing and controlling the other of the two swimming legs not to swing, the all-directional surface swimming robot moves in the plane where the robot body is located and moves in the direction of the other of the two swimming legs; by controlling the two swimming legs to swing synchronously, the all-directional surface swimming robot moves along the normal direction of the plane where the robot body is located.

2. The all-directional surface swimming robot according to claim 1, wherein, The robot body is in a cylindrical shape, the two swimming legs are located in the same plane, and the distance between the installation positions of the two swimming legs on the robot body is the diameter of the robot body.

3. The omnidirectional surface swimming robot according to claim 1 or 2, characterized in that, The swimming leg includes a waterproof servo and a multi-passive joint thruster. The waterproof servo is installed on the robot body, and the multi-passive joint thruster is connected to the steering wheel of the waterproof servo.

4. The omnidirectional swimming robot on the water surface according to claim 3, characterized in that, The multi-passive joint thruster includes a plurality of rigid sheets. The plurality of rigid sheets are arranged at intervals, and two adjacent rigid sheets are connected by a flexible member. The rigid sheet connected to the waterproof servo among the plurality of rigid sheets is connected to the steering wheel of the waterproof servo through a rigid link.

5. The omnidirectional surface swimming robot according to claim 4, wherein, The flexible member is made of spring steel.

6. The all-directional surface swimming robot according to claim 4, wherein An inertial measurement unit is provided on each of the other rigid sheets except the rigid sheet connected to the waterproof servo among the plurality of rigid sheets.

7. The omnidirectional surface swimming robot according to claim 4, wherein, A central pattern generator is provided on each of the other rigid sheets except the rigid sheet connected to the waterproof servo among the plurality of rigid sheets.

8. The omnidirectional swimming robot on the water surface according to claim 1, wherein, The robot body includes a bottom shell and an upper shell, and the bottom shell and the upper shell are fixedly combined with each other through a rabbet structure.

9. The omnidirectional swimming robot on the water surface according to claim 8, characterized in that, Sealant is provided at the joint gap between the bottom shell and the upper shell.

10. A motion control method for the omnidirectional swimming robot on the water surface according to any one of claims 1-9, characterized in that, The motion control method includes: By controlling one of the two swimming legs to swing and controlling the other of the two swimming legs not to swing, the all-directional surface swimming robot moves in the plane where the robot body is located and moves in the direction of the other of the two swimming legs; By controlling the two swimming legs to swing synchronously, the all-directional surface swimming robot moves along the normal direction of the plane where the robot body is located.

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