Underwater robotic fish bionic pectoral fin deformation sensing method and system

Abstract

The invention relates to the technical field of underwater bionic robots, in particular to an underwater robotic fish bionic pectoral fin deformation sensing method and system, an inertial measurement unit is arranged on a passive connecting rod to be measured, the inertial measurement unit is utilized to directly obtain real-time attitude angle data, and the angular motion of the passive connecting rod is directly measured; errors caused by perspective and calibration in an image recognition method are avoided, and the measurement precision is high; a complicated image processing process is not needed, millisecond-level real-time sensing of a passive deformation state can be realized, and the requirement of high-speed closed-loop control is met; meanwhile, an additional visual system does not need to be arranged for data acquisition, the size, weight and power consumption of the system are reduced, and deployment on a miniaturized and integrated robotic fish platform is facilitated; the system does not depend on optical conditions, can work normally in a muddy water, dark light or dark environment, and is high in environmental interference resistance and wider in application scene.

Description

Technical Field

[0001] This invention relates to the field of underwater biomimetic robot technology, specifically to a method and system for sensing the deformation of the pectoral fins of an underwater robotic fish. Background Technology

[0002] The pectoral fins of ray-like creatures exhibit remarkable propulsion efficiency and maneuverability during swimming. The core biomechanical principle behind this lies in the complex passive deformation of the pectoral fin structure under hydrodynamic forces, both longitudinally (from the body towards the outer edge) and chordally (from the leading edge to the trailing edge). This passive deformation, coupled with active deformation driven by muscles, is key to their efficient, low-noise, and agile movement. Therefore, incorporating passive deformation characteristics into the design of biomimetic robotic fish has become an important biomimetic approach to improving their hydrodynamic performance.

[0003] Currently, the understanding and research on passive deformation of pectoral fins in the field of biomimetic robotic fish has not fully utilized the laws of passive deformation. Existing technical solutions mainly focus on verifying the gains in macroscopic performance, such as propulsion speed and efficiency, by comparing robotic fish models with and without passive deformation designs. For example, Chinese invention patent CN 119370301A uses a multi-jointed pectoral fin structure design to achieve the flapping motion of biomimetic manta ray pectoral fins to improve the propulsion efficiency of biomimetic manta ray robotic fish. However, the common limitation of such patents and research is that they only regard passive deformation as a holistic, qualitative "presence or absence" variable, or only conduct rough simulations based on the constitutive relations of specific materials, without in-depth exploration and quantitative description of the dynamic process, spatial distribution, and real-time coupling law between passive deformation and active drive.

[0004] While integrated sensing solutions for closed-loop control exist, such as the Chinese invention patent with publication number CN 120491497A, which achieves passive deformation through a structure combining a rigid fin root with flexible fin rays and a flexible fin membrane, and designs a complex sensing system for fin-driven pectoral fins consisting of a bending sensor, strain gauge array, angle encoder, and six-dimensional force sensor to acquire multi-dimensional information such as the passive bending angle of the fin rays and the local fluid load distribution, this method is overly complex and places high demands on the sensors. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for sensing the deformation of biomimetic pectoral fins in underwater robotic fish, thereby solving the technical problem of the high difficulty in passively sensing the deformation of biomimetic pectoral fins in robotic fish that mimic the manta ray suborder.

[0006] The solution of the present invention to the above-mentioned technical problems is as follows: A biomimetic pectoral fin deformation sensing method for underwater robotic fish, applied to underwater robotic fish with active and passive linkages; includes the following steps: Define a fixed coordinate system for the robotic fish's body; For the target passive link, its motion variable is defined as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body; An inertial measurement unit is placed on the passive link to be measured, and the measurement axis of the inertial measurement unit is parallel to the rotation axis of the passive link to be measured. The motion variables of the passive link are calculated based on the attitude angles measured by the inertial measurement unit. The underwater robotic fish's biomimetic pectoral fin deformation is perceived by utilizing the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

[0007] Further specifying, the defined fixed coordinate system of the robotic fish body is as follows: Set the center of gravity or geometric center of the robotic fish as the origin. ; The longitudinal axis of the robotic fish points in the direction of its movement. axis; Perpendicular to The axis points to the right of the robotic fish. axis; Perpendicular to The plane points to the lower ventral side of the robotic fish and is aligned with... shaft and The axes that form a right-handed coordinate system are axis.

[0008] Further defined, the reference plane is the horizontal plane formed by the longitudinal axis and the transverse axis of the fixed coordinate system of the robotic fish body; when the passive link is located above the reference plane, the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body is a positive value; when the passive link is located above the reference plane, the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body is a negative value.

[0009] Further defined, the underwater robotic fish includes a robotic fish body and pectoral fins located on the left and right sides of the robotic fish body respectively; the pectoral fins include: First active rod, second active rod, second passive rod, first passive rod, second inertial measurement unit, and first inertial measurement unit; The first active lever is movably connected to the body of the robotic fish via a first servo motor, and is used to actively drive the pectoral fin in the chord direction; the second active lever is movably connected to the body of the robotic fish via a second servo motor, and is used to actively drive the pectoral fin in the spanwise direction; the first passive lever is hinged to the body of the robotic fish via a first rotary hinge, and is used to achieve passive deformation in the chord direction; the second passive lever is hinged to the end of the second active lever via a second rotary hinge, and is used to achieve passive deformation in the spanwise direction. The second inertial measurement unit is mounted on the second passive rod, and the measurement axis of the second inertial measurement unit is parallel to the axis of the second rotary hinge; the first inertial measurement unit is mounted on the first passive rod, and the measurement axis of the first inertial measurement unit is parallel to the axis of the first rotary hinge.

[0010] Furthermore, the angle between the passive link and the designated reference plane in the fish's fixed coordinate system includes the spanwise deformation angle of the second passive link. And the chordal deformation angle of the first passive rod ; The spanwise deformation angle The axis of the second passive rod is intersected with... The angle between the planes; when the second passive rod is directed towards When the axis swings in the negative direction, >0; when the second passive rod moves towards When the axis swings in the positive direction, <0; The chordal deformation angle The axis of the first passive rod is intersected with... The angle between the planes, when the first passive rod is directed towards When the axis swings in the negative direction, >0; when the first passive lever moves towards When the axis swings in the positive direction, <0.

[0011] Further specifying, the calculation of the motion variables of the passive link based on the attitude angles measured by the inertial measurement unit specifically involves: Obtain the real-time spanwise deformation angle of the second passive rod. And the real-time chordal deformation angle of the first passive rod :

[0012]

[0013] in, The Euler angles output in real time by the second inertial measurement unit around its measurement axis. The original angle output by the second inertial measurement unit when the pectoral fin is in a known reference attitude; The Euler angles output in real time by the first inertial measurement unit around its measurement axis. The original angle output by the first inertial measurement unit when the pectoral fin is in the reference posture.

[0014] Further specifying, the process of sensing the deformation of the underwater robotic fish's pectoral fin based on the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link includes the following steps: Calculate the coordinates of each movement point of the pectoral fin; The coordinates of each movement point of the pectoral fin are converted into quantifiable passive deformation state parameters, enabling passive deformation perception of the manta ray-like robotic fish.

[0015] Further specifying the steps for calculating the coordinates of each movement point of the pectoral fin: Identify the points of motion for the pectoral fins: Anterior base of the pectoral fin The posterior base of the pectoral fin The starting point of rotation of the first active rod 1 Second driving rod rotation starting point The starting point of rotation of the first passive rod Coordinates of the end point of the first driving rod Coordinates of the end point of the first passive rod Coordinates of the end point of the second driving rod Coordinates of the end point of the second passive rod ; The points of movement of the pectoral fins are at Coordinates in a coordinate system:

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] in, The chord length of the pectoral fin. The width of the robotic fish's body; The distance between the first and second driving links. The distance between the first passive link and the second active link; The length of the first active rod, The length of the first passive rod. The length of the second active rod. The length of the second passive rod; The chord-direction active motion angle of the first active rod. The spanwise active motion angle of the second active rod.

[0025] A biomimetic pectoral fin deformation sensing system for an underwater robotic fish, applied to an underwater robotic fish with active and passive linkages, realizes the aforementioned biomimetic pectoral fin deformation sensing method for the underwater robotic fish, including: The coordinate system establishment unit is used to define the fixed coordinate system of the robotic fish body; The motion variable establishment unit is used to define the motion variable of the target passive link as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body. A passive link motion variable calculation unit is used to calculate the motion variables of the passive link based on the attitude angles measured by the inertial measurement unit; the inertial measurement unit is installed on the passive link to be measured, and the measurement axis of the inertial measurement unit is parallel to the rotation axis of the passive link to be measured. The deformation sensing unit is used to realize the deformation sensing of the biomimetic pectoral fin of the underwater robotic fish based on the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

[0026] A computing device, comprising: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including steps for performing the above-described underwater robotic fish biomimetic pectoral fin deformation sensing method.

[0027] The beneficial effects of this invention are as follows: This invention places an inertial measurement unit (IMU) on the passive link to be measured, directly obtaining real-time attitude angle data and measuring the angular motion of the passive link. This avoids errors caused by perspective and calibration in image recognition methods, resulting in high measurement accuracy. Furthermore, it eliminates the need for complex image processing, enabling millisecond-level real-time perception of passive deformation states, meeting the requirements of high-speed closed-loop control. Simultaneously, data acquisition does not require an additional vision system, reducing system size, weight, and power consumption, facilitating deployment on miniaturized, integrated robotic fish platforms. It is independent of optical conditions, operating normally in murky water, low light, or no-light environments, exhibiting strong resistance to environmental interference and a wider range of applications. Attached Figure Description

[0028] Figure 1 This is a structural diagram of the underwater robotic fish of the present invention; Figure 2 This is a schematic diagram of the fixed coordinate system of the underwater robotic fish of the present invention; Figure 3 This is a schematic diagram of the motion variables of the linkage of the underwater robotic fish of the present invention; Figure 4This is a schematic diagram of the movement points of the pectoral fin in the underwater robotic fish of the present invention; Figure 5 A schematic diagram of the computer device provided by the present invention; Figure 6 A block diagram of a chip provided by the present invention.

[0029] In the diagram, 1-First active lever; 2-Second active lever; 3-Second passive lever; 4-First passive lever; 5-Second inertial measurement unit; 6-First inertial measurement unit; 60-Computer equipment; 61-Processor; 62-Memory; 63-Computer program; 600-Electronic device; 610-Processing unit; 620-Storage unit; 6201-Random access memory unit; 6202-Cache memory unit; 6203-Read-only memory unit; 6204-Program / utility; 6205-Program module; 630-Bus; 640-Display unit; 650-Input / output interface; 660-Network adapter; 700-External device. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0033] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] Achieving accurate perception and mathematical representation of the passive deformation of complex curved surfaces is the core bottleneck to overcoming the aforementioned limitations. Current experimental measurements of passive deformation mostly employ visual recognition methods based on high-speed cameras. While these methods can provide deformation information in laboratory environments, they suffer from significant shortcomings in real-time performance, underwater interference resistance, measurement range, ease of data processing, and feasibility of integration with control systems. This lack of perception capability directly leads to difficulty in perception and consequently, difficulty in representation, which in turn creates a mutually constraining situation of difficulty in perception. Because high-fidelity, full-state deformation data cannot be obtained, researchers struggle to establish mathematical models that accurately describe the spatiotemporal evolution of passive deformation; conversely, the lack of effective theoretical models hinders the targeted design of perception systems and makes it difficult to extract key features from massive amounts of data.

[0035] refer to Figure 1 A biomimetic pectoral fin deformation sensing method for an underwater robotic fish is disclosed, applicable to an underwater robotic fish with active and passive linkages. The underwater robotic fish includes a body and pectoral fins located on the left and right sides of the body. The pectoral fins on both sides have identical structures; therefore, the left side is used as an example. The pectoral fin includes: First active rod 1, second active rod 2, second passive rod 3, first passive rod 4, second inertial measurement unit 5, and first inertial measurement unit 6.

[0036] The first active link 1 and the second active link 2 are active connecting links, and the second passive link 3 and the first passive link 4 are passive connecting links. The first active link 1 is movably connected to the body of the robotic fish through the first servo motor and is used to actively drive the pectoral fin in the chord direction. The second active link 2 is movably connected to the body of the robotic fish through the second servo motor and is used to actively drive the pectoral fin in the spanwise direction. The first passive link 4 is hinged to the body of the robotic fish through the first rotary hinge and is used to achieve passive deformation in the chord direction. The second passive link 3 is hinged to the end of the second active link 2 through the second rotary hinge and is used to achieve passive deformation in the spanwise direction.

[0037] The IMU2 (second inertial measurement unit 5) is mounted on the second passive rod 3. During installation, the second inertial measurement unit 5 is adjusted in attitude using a calibration tool so that its measurement axis is parallel to the axis of the second rotary hinge. Similarly, the IMU1 (first inertial measurement unit 6) is mounted on the first passive rod 4, and its measurement axis is parallel to the axis of the first rotary hinge to ensure the consistency between the IMU measurement axis and the rotation axis of the passive rod.

[0038] Preferably, silicone potting or a custom waterproof shell is used to completely seal the IMU and connecting cables, ensuring that they can work reliably for a long time in underwater pressure environments.

[0039] Example 1 This invention provides a method for sensing the deformation of the pectoral fins of an underwater robotic fish, comprising the following steps: Define a fixed coordinate system for the robotic fish's body; For the target passive link, its motion variable is defined as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body; An inertial measurement unit (IMU) is placed on the passive link to be measured, and the IMU measures... The motion variables of the passive link are calculated based on the attitude angles measured by the inertial measurement unit. The underwater robotic fish's biomimetic pectoral fin deformation is perceived by utilizing the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

[0040] For further explanation, please refer to Figure 2 Define the fixed coordinate system of the robotic fish body. Specifically: Set the center of gravity or geometric center of the robotic fish as the origin. ; The longitudinal axis of the robotic fish points in the direction of its movement. axis; Perpendicular to The axis points to the right of the robotic fish. axis; Perpendicular to The plane points to the lower ventral side of the robotic fish and is aligned with... shaft and The axes that form a right-handed coordinate system are axis.

[0041] For further explanation, please refer to Figure 3 For ease of calculation, the reference plane is preferably the horizontal plane formed by the longitudinal axis and the transverse axis of the fixed coordinate system of the robotic fish; such that when the passive link is above the reference plane, the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish is positive; and when the passive link is above the reference plane, the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish is negative.

[0042] Specifically, the angle between the passive link and the specified reference plane in the fish's fixed coordinate system includes the spanwise deformation angle of the second passive link 3. And the chordal deformation angle of the first passive rod 4 ; spanwise deformation angle The axis of the second passive rod 3 is intersected with... The angle between the planes; when the second passive rod is in direction 3 When the axis swings in the negative direction, >0; When the second passive rod moves in direction 3 When the axis swings in the positive direction, <0; chordal deformation angle The axis of the first passive rod 4 is intersected with... The angle between the planes, when the first passive rod is in 4 directions When the axis swings in the negative direction, >0; When the first passive lever moves in 4 directions When the axis swings in the positive direction, <0.

[0043] To further explain, the motion variables of the passive link are calculated based on the attitude angles measured by the inertial measurement unit as follows: When the underwater robotic fish is static and its pectoral fins are adjusted to a known baseline posture, for example, when both the active and passive links are in a certain position... In the plane, that is , At this time, record the raw angle readings output by the two IMUs, IMU1 and IMU2. and .

[0044] Thus, during the motion, the real-time spanwise deformation angle of the second passive rod 3 is obtained. And the real-time chordal deformation angle of the first passive rod 4 :

[0045]

[0046] in, The Euler angles output in real time by the second inertial measurement unit 5 around its measurement axis. The original angle output by the second inertial measurement unit 5 when the pectoral fin is in a known reference posture; The Euler angles output in real time by the first inertial measurement unit 6 around its measurement axis. The original angle output by the first inertial measurement unit 6 when the pectoral fin is in the reference posture.

[0047] To further explain, the process of sensing the deformation of the underwater robotic fish's pectoral fins based on the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link includes the following steps: Calculate the coordinates of each movement point of the pectoral fin; The coordinates of each movement point of the pectoral fin are converted into quantifiable passive deformation state parameters, enabling passive deformation perception of the manta ray-like robotic fish.

[0048] For details, please refer to Figure 4 The following steps are used to calculate the coordinates of each movement point of the pectoral fin: Identify the points of motion for the pectoral fins: Anterior base of the pectoral fin The posterior base of the pectoral fin The starting point of rotation of the first active rod 1 Second active rod 2 rotation starting point The first passive rod 4 rotation starting point Coordinates of the end point of the first active rod 1 Coordinates of the end point of the first passive rod 4 Coordinates of the end point of the second active rod 2 Coordinates of the end point of the second passive rod 3 ; The points of movement of the pectoral fins are at Coordinates in a coordinate system:

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] in, The chord length of the pectoral fin. The width of the robotic fish's body; The distance between the first active link 1 and the second active link 2 is... The distance between the first passive rod 4 and the second active rod 2; The length of the first active rod 1 The length of the first passive rod 4, The length of the second active rod 2 The length of the second passive rod 3; The chordal active motion angle of the first active link 1, The spanwise active motion angle of the second active link 2; and The output is controlled by the first and second servo motors, which facilitates data acquisition.

[0058] Because the pectoral fins are bilaterally symmetrical, the coordinates of the motion points corresponding to the left and right pectoral fins can be obtained separately; the coordinate values ​​of these points change with the movement of the active and passive rods during the biomimetic pectoral fin movement.

[0059] Finally, after calculating the coordinates of each movement point of the left and right pectoral fins, a mathematical model was established to transform the coordinate information of each movement point into quantifiable passive deformation state parameters, thereby realizing the passive deformation perception of the manta ray-like robotic fish and providing a foundation for the movement and control of the robotic fish.

[0060] Example 2 This embodiment provides an underwater robotic fish bionic pectoral fin deformation sensing system to implement the underwater robotic fish bionic pectoral fin deformation sensing method described in Embodiment 1, including: The coordinate system establishment unit is used to define the fixed coordinate system of the robotic fish body; The motion variable establishment unit is used to define the motion variable of the target passive link as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body. A passive link motion variable calculation unit is used to calculate the motion variables of the passive link based on the attitude angles measured by the inertial measurement unit; the inertial measurement unit is installed on the passive link to be measured, and the measurement axis of the inertial measurement unit is parallel to the rotation axis of the passive link to be measured. The deformation sensing unit is used to realize the deformation sensing of the biomimetic pectoral fin of the underwater robotic fish based on the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

[0061] Example 3 This invention provides a terminal device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to achieve a corresponding method flow or corresponding function. The processor described in this embodiment can be used to perform the operation of the underwater robotic fish biomimetic pectoral fin deformation sensing method described in Embodiment 1, including: Define a fixed coordinate system for the robotic fish's body; For the target passive link, its motion variable is defined as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body; The motion variables of the passive link are calculated based on the attitude angles measured by the inertial measurement unit; the inertial measurement unit is set on the passive link to be measured, and the measurement axis of the inertial measurement unit is parallel to the rotation axis of the passive link to be measured. The underwater robotic fish's biomimetic pectoral fin deformation is perceived by utilizing the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

[0062] Please see Figure 5 The terminal device is a computer device. In this embodiment, the computer device 60 includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When executed by the processor 61, the computer program 63 implements the method for estimating the concentration of radioactive iodine species in the containment vessel after an accident, as described in this embodiment. To avoid repetition, these methods are not detailed here. Alternatively, when executed by the processor 61, the computer program 63 implements the functions of each model / unit in the system of this embodiment*. To avoid repetition, these functions are not detailed here.

[0063] Computer device 60 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. Computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will understand that... Figure 5 This is merely an example of computer device 60 and does not constitute a limitation on computer device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, computer device may also include input / output devices, network access devices, buses, etc.

[0064] The processor 61 may be a Central Processing Unit (CPU), or other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0065] The memory 62 can be an internal storage unit of the computer device 60, such as a hard disk or RAM of the computer device 60. The memory 62 can also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the computer device 60.

[0066] Furthermore, the memory 62 may include both internal storage units and external storage devices of the computer device 60. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 can also be used to temporarily store data that has been output or will be output.

[0067] Please see Figure 6 The terminal device is an electronic device 600, which is manifested in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including storage unit 620 and processing unit 610), a display unit 640, etc.

[0068] The storage unit stores program code, which can be executed by the processing unit 610, causing the processing unit 610 to perform the steps described in the above-described method section of this specification according to various exemplary embodiments of the present invention.

[0069] Storage unit 620 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 6201 and / or cache memory 6202, and may further include a read-only memory (ROM) 6203.

[0070] Storage unit 620 may also include a program / utility 6204 having a set (at least one) program module 6205, such program module 6205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0071] Bus 630 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the multiple bus structures.

[0072] Electronic device 600 can also communicate with one or more external devices 700 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 600, and / or with any device that enables electronic device 600 to communicate with one or more other computing devices (e.g., router, modem). This communication can be performed via input / output interface 650. Furthermore, electronic device 600 can also communicate with one or more networks (e.g., local area network, wide area network, and / or public network, such as the Internet) via network adapter 660. Network adapter 660 can communicate with other modules of electronic device 600 via bus 630. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0073] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0074] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for sensing pectoral fin deformation in an underwater robotic fish, characterized in that, Applied to underwater robotic fish with active and passive linkages; including the following steps: Define a fixed coordinate system for the robotic fish's body; For the target passive link, its motion variable is defined as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body; An inertial measurement unit is placed on the passive link to be measured, and the measurement axis of the inertial measurement unit is parallel to the rotation axis of the passive link to be measured. The motion variables of the passive link are calculated based on the attitude angles measured by the inertial measurement unit. The underwater robotic fish's biomimetic pectoral fin deformation is perceived by utilizing the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

2. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 1, characterized in that, The defined fixed coordinate system for the robotic fish body is specifically as follows: Set the center of gravity or geometric center of the robotic fish as the origin. ; The longitudinal axis of the robotic fish points in the direction of its movement. axis; Perpendicular to The axis points to the right of the robotic fish. axis; Perpendicular to The plane points to the lower ventral side of the robotic fish and is aligned with... shaft and The axes that form a right-handed coordinate system are axis.

3. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 1, characterized in that, The reference plane is the horizontal plane formed by the longitudinal axis and the transverse axis of the fixed coordinate system of the robotic fish body; when the passive link is located above the reference plane, the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body is a positive value. When the passive link is located above the reference plane, the angle between the passive link and the specified reference plane in the fish's fixed coordinate system is negative.

4. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 3, characterized in that, The underwater robotic fish includes a robotic fish body and pectoral fins located on the left and right sides of the robotic fish body, respectively; the pectoral fins include: First active rod (1), second active rod (2), second passive rod (3), first passive rod (4), second inertial measurement unit (5) and first inertial measurement unit (6); The first active lever (1) is movably connected to the body of the robotic fish via a first servo motor and is used for active chordal drive of the pectoral fin; the second active lever (2) is movably connected to the body of the robotic fish via a second servo motor and is used for active spanwise drive of the pectoral fin; the first passive lever (4) is hinged to the body of the robotic fish via a first rotary hinge and is used for passive chordal deformation; the second passive lever (3) is hinged to the end of the second active lever (2) via a second rotary hinge and is used for passive spanwise deformation. The second inertial measurement unit (5) is mounted on the second passive rod (3), and the measurement axis of the second inertial measurement unit (5) is parallel to the axis of the second rotary hinge; the first inertial measurement unit (6) is mounted on the first passive rod (4), and the measurement axis of the first inertial measurement unit (6) is parallel to the axis of the first rotary hinge.

5. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 4, characterized in that, The angle between the passive link and the designated reference plane in the fish's fixed coordinate system includes the spanwise deformation angle of the second passive link (3). The chordal deformation angle of the first passive rod (4) ; The spanwise deformation angle The axis of the second passive rod (3) is perpendicular to... The angle between the planes; when the second passive rod (3) moves towards When the axis swings in the negative direction, >0; when the second passive rod (3) moves towards When the axis swings in the positive direction, <0; The chordal deformation angle The axis of the first passive rod (4) is parallel to... The angle between the planes, when the first passive rod (4) moves towards When the axis swings in the negative direction, >0; When the first passive rod (4) moves towards When the axis swings in the positive direction, <0.

6. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 5, characterized in that, The specific steps for calculating the motion variables of the passive link based on the attitude angles measured by the inertial measurement unit are as follows: Obtain the real-time spanwise deformation angle of the second passive rod (3) The real-time chordal deformation angle of the first passive rod (4) : in, The Euler angles output in real time by the second inertial measurement unit (5) around its measurement axis. The original angle output by the second inertial measurement unit (5) when the pectoral fin is in a known reference posture; The Euler angles output in real time by the first inertial measurement unit (6) around its measurement axis. The original angle output by the first inertial measurement unit (6) when the pectoral fin is in the reference posture.

7. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 6, characterized in that, The process of sensing the deformation of the biomimetic pectoral fins of the underwater robotic fish based on the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link includes the following steps: Calculate the coordinates of each movement point of the pectoral fin; The coordinates of each movement point of the pectoral fin are converted into quantifiable passive deformation state parameters, enabling passive deformation perception of the manta ray-like robotic fish.

8. The underwater robotic fish biomimetic pectoral fin deformation sensing method according to claim 7, characterized in that, The following steps are used to calculate the coordinates of each movement point of the pectoral fin: Identify the points of motion for the pectoral fins: Anterior base of the pectoral fin The posterior base of the pectoral fin The starting point of rotation of the first active rod 1 Second active rod (2) rotation starting point The first passive rod (4) rotation starting point The coordinates of the end point of the first active rod (1) The coordinates of the end point of the first passive rod (4) The coordinates of the end point of the second active rod (2) Coordinates of the end point of the second passive rod (3) ; The points of movement of the pectoral fins are at Coordinates in a coordinate system: in, The chord length of the pectoral fin. The width of the robotic fish's body; The distance between the first active rod (1) and the second active rod (2) is... The distance between the first passive rod (4) and the second active rod (2); The length of the first active rod (1) The length of the first passive rod (4) The length of the second active rod (2) The length of the second passive rod (3); The chordal active motion angle of the first active rod (1) is... The spanwise active motion angle of the second active rod (2).

9. A biomimetic pectoral fin deformation sensing system for an underwater robotic fish, characterized in that, Applied to underwater robotic fish with active and passive linkages, implementing the biomimetic pectoral fin deformation sensing method for underwater robotic fish as described in any one of claims 1 to 8, comprising: The coordinate system establishment unit is used to define the fixed coordinate system of the robotic fish body; The motion variable establishment unit is used to define the motion variable of the target passive link as the angle between the passive link and the specified reference plane in the fixed coordinate system of the fish body. A passive link motion variable calculation unit is used to calculate the motion variables of the passive link based on the attitude angles measured by the inertial measurement unit; the inertial measurement unit is installed on the passive link to be measured, and the measurement axis of the inertial measurement unit is parallel to the rotation axis of the passive link to be measured. The deformation sensing unit is used to realize the deformation sensing of the biomimetic pectoral fin of the underwater robotic fish based on the motion variables of the active link, the size of the robotic fish, and the motion variables of the passive link.

10. A computing device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including steps for performing the underwater robotic fish biomimetic pectoral fin deformation sensing method according to any one of claims 1 to 8.

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