An underwater adherent robot with mixed driving of paddle leg

Abstract

The application discloses an underwater adhering robot with mixed driving of paddle legs, relates to the technical field of underwater robots, and has the advantages of long-distance cruising driving, stable climbing on unstructured terrain and reliable adhesion detection on a near-wall surface of a screw propeller driving, six-foot climbing movement and a hydrogel bionic sucker equipped on the foot bottom, thereby solving the adaptability problem of a single-mode underwater robot in a complex operation scene. The underwater adhering robot with mixed driving of paddle legs can realize the functions of seabed climbing, obstacle climbing, attitude adjustment and other multi-mode movement functions through the cooperation of six groups of multi-degree-of-freedom mechanical feet, modular driving units and a control system. The underwater adhering robot can realize stable climbing on a vertical or inverted surface through the cooperation of the hydrogel bionic sucker equipped on the foot end and the six-foot climbing gait. The underwater adhering robot can meet the multi-degree-of-freedom movement control requirements of forward movement, backward movement, upward movement, downward movement, yawing, pitching, heaving and hovering through the vector combination of three vertical propellers and two horizontal propellers. The underwater adhering robot with mixed driving of paddle legs maximizes the development of underwater mixed driving potential, improves underwater mobility in various challenging underwater environments, and promotes the development of underwater robots towards multi-mode and high efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underwater robots, in particular to an underwater adhering robot with paddle-leg hybrid driving. BACKGROUND

[0002] With the increasing demand for ocean resource development, ecological monitoring, and other needs, many infrastructures and equipment in aquatic environments have been rapidly constructed and developed, including ships, bridges and dams, offshore platforms and submarine pipelines, and many countries and related industries have established standards for regular inspection, cleaning and maintenance of infrastructures and equipment.

[0003] Traditional underwater robots generally use propeller propulsion systems, which have high propulsion performance and mature navigation algorithms, showing significant advantages in open waters, such as long-distance cruising and data collection tasks, but face significant challenges in complex scenarios: insufficient maneuverability in narrow pipe networks, poor stability in strong current environments, and reliable detection of vertical or inverted surfaces. Pure legged robots are limited by low water power efficiency, weak resistance to flow, high energy consumption, and other problems, making it difficult to balance movement efficiency and stability in dynamic flow fields; therefore, a new type of underwater robot solution is needed that combines terrain adaptability and dynamic stability.

[0004] The integration of underwater robots and bionics is an effective way to overcome the inherent limitations of existing underwater robots. As real-world scenarios become more complex, multi-modal motion is increasingly attracting attention. Combining propeller propulsion with foot-based walking can provide both long-distance cruising and terrain adaptability, meeting most underwater task requirements, but some ship cleaning, crack detection and damage repair tasks require the robot to adhere tightly to the surface of underwater structures to perform detailed small-range operations, and conventional robots cannot adhere to these surfaces; therefore, the existing needs are not met, and we propose an underwater adhering robot with paddle-leg hybrid driving. SUMMARY

[0005] The present application aims to provide an underwater adhering robot with propeller driving and hexapod crawling multi-modal motion capability, which uses propeller propulsion for long-distance cruising tasks, adopts hexapod crawling motion for unstructured terrains such as submarine pipelines, and activates the hydrogel biomimetic suction cups at the bottom of the hexapod for reliable detection tasks that require close adherence to the surface or even vertical or inverted surfaces, aiming to improve the problem that existing underwater robots cannot adapt to complex scenarios and diverse operation tasks.

[0006] To solve the above technical problems, the underwater adhering robot with paddle leg hybrid drive is realized by the following technical scheme: a kind of underwater adhering robot with paddle leg hybrid drive, including robot main body, electronic sealed cabin and pressure sensor are arranged in the inside of main body, three vertical propellers are arranged in the front and rear of main body, one horizontal propeller is arranged in the rear of main body, two LED searchlights and a camera are arranged in the head of main body, cable communication interface is arranged in the tail of main body, six groups of leg crawling mechanisms are distributed symmetrically outside main body.

[0007] The above-mentioned electronic sealed cabin includes all electronic elements for controlling the movement of the robot, including Raspberry Pi as the main controller for sending movement instructions and communicating with the host computer, PCA9685 control board and flight controller as the slave controller, PCA9685 is used to send control instructions to drive six groups of 18 waterproof rudders and leg diaphragm pumps for controlling water gel bionic suction cups, flight controller is used to send instructions to drive three vertical propellers and two horizontal propellers, flight controller includes gyroscope and accelerometer inside, for measuring robot attitude and acceleration information, electronic speed regulator, LED drive board and power module are also included in the electronic elements, electronic speed regulator is used to convert control signals sent by flight controller into digital signals to drive brushless motor, LED drive board is used to control LED searchlights in the head of main body, power module is used to supply power to all components of the robot.

[0008] The above-mentioned pressure sensor is installed just below the inside of the robot main body, for measuring the depth information of the robot in water.

[0009] Preferably, the three vertical propellers are fixed to the robot shell by bolts, composed of 930kv brushless motor and propeller, the vertical propellers realize ascending and descending movement by rotating at constant speed in the same direction, the vertical propellers realize pitching movement by rotating at constant speed in opposite directions, and the vertical propellers realize rolling movement by reverse movement of vertical propellers on both sides of the front of main body.

[0010] Preferably, the horizontal propellers on both sides of the robot main body are fixed to the robot shell by base, composed of 980kv brushless motor and propeller, the horizontal propellers realize forward and backward movement by rotating at constant speed in the same direction, and the vertical propellers realize turning movement by rotating at constant speed in opposite directions.

[0011] Preferably, the LED searchlights are fixed to the head of the robot by bolts, the searchlights are composed of 5W LED lamp beads and waterproof spotlight lens, and waterproof function is realized by epoxy resin casting.

[0012] Preferably, the camera is fixed to the robot head by bolts, the camera parameters are 1080P high-definition USB camera module, 3.6mm focal length lens, 90 degree view angle, and the camera is placed in a small sealed cabin to realize waterproof function by epoxy resin pouring.

[0013] Preferably, the cable communication interface is fixed to the tail of the robot by bolts, the communication interface is composed of WF16-10 core waterproof socket, and waterproof function is realized by sealing ring and epoxy resin pouring.

[0014] Preferably, the leg climbing mechanism is fixed to the outside of the robot body by bolts, the leg climbing mechanism is composed of three joints, the sizes of the three joints are 48mm, 76mm and 147mm in turn, the joints are respectively driven by three IPX8 waterproof digital servos, a diaphragm pump is arranged in the third joint inside the climbing mechanism, the diaphragm pump realizes waterproof function by epoxy resin pouring, the foot end of the climbing mechanism is provided with a hydrogel bionic suction cup, the hydrogel bionic suction cup is prepared by digital light processing 3D printing Zr4+ coordination hydrogel, the hydrogel has mechanical strength and swelling resistance by double network toughening strategy, and the hydrogel suction cup is provided with a communication loop, and the adhesion and detachment functions of the suction cup are realized by opening and closing of the diaphragm pump.

[0015] Compared with the prior art, the beneficial effects of the present application are:

[0016] 1. The underwater robot disclosed in the present application has full-terrain adaptability in narrow space in the six-legged climbing mode, the bionic joint structure of the underwater robot is designed based on the bionics principle of enhancing stability and optimizing contact force distribution, six groups of multi-degree-of-freedom mechanical feet realize the cooperation of modular driving units and control systems, so that the robot can realize the functions of seabed climbing, obstacle climbing, attitude adjustment and other multi-modal motion functions, and the mode can be applied to complex seabed terrain exploration, equipment maintenance and other fine operation tasks.

[0017] 2. The hydrogel bionic suction cup equipped at the foot end of the underwater robot disclosed in the present application has the ability to stably adhere to the surface of underwater structure, the hydrogel suction cup is provided with a communication loop inside, the adhesion and detachment functions are realized by opening and closing of the diaphragm pump, the cooperation of the gait design in the six-legged climbing mode and the diaphragm pump enables the robot to realize stable climbing on the vertical or inverted surface, and the mode can be applied to ship cleaning, crack detection and damage repair near the wall surface operation tasks.

[0018] 3. The underwater robot disclosed in the application has 5 degrees of freedom in the propeller driving mode, the streamlined appearance and the configuration and installation of the propeller of the underwater robot are designed based on the criteria of reducing water resistance and improving space utilization, the vector combination arrangement of three vertical propellers and two horizontal propellers enables the robot to meet the requirements of multi-degree-of-freedom motion control such as forward movement, backward movement, upward movement, downward movement, yawing, pitching, rolling and hovering, and the mode can be applied to long-distance cruising and data collection tasks. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 It is the overall structural schematic diagram of the application;

[0020] Fig. 2 It is the overall top view of the application;

[0021] Fig. 3 It is the single-leg three-dimensional structural schematic diagram of the application;

[0022] Fig. 4 It is the three-dimensional structural schematic diagram of the hydrogel bionic suction cup of the application;

[0023] Fig. 5 It is the vertical propeller structural schematic diagram of the application;

[0024] Fig. 6 It is the horizontal propeller structural schematic diagram of the application;

[0025] Fig. 7 It is the IPX8 waterproof steering engine structural schematic diagram of the application.

[0026] In the diagram: Front housing 1, Rear housing 2, Leg-type walking mechanism 3, Vertical propeller thruster 4, Horizontal propeller thruster 5, Communication cable interface 6, Left LED light 701, Right LED light 702, Camera 8, Left front leg 901, Right front leg 902, Left middle leg 903, Right middle leg 904, Left rear leg 905, Right rear leg 906, Left front vertical thruster 1001, Right front vertical thruster 1002, Rear vertical thruster 1003, Left horizontal thruster 1101, Right horizontal thruster 1102, Leg first joint 1201, Leg second joint 1202, Leg third joint 1203, First joint waterproof servo 1301, Second joint waterproof multi-stage 1302, Third joint waterproof servo 1303, ... A joint connecting plate 14, a diaphragm pump 15, a hydrogel suction cup 16, a suction cup top base 1701, a suction cup internal connecting circuit 1702, a support column 1703, a suction cup bottom base 1704, a suction cup bionic strut 1705, a vertical propeller base 1801, a motor rotating shaft 1802, a vertical propeller fixing shaft 1803, a vertical propeller fixing hole 1804, a 930kV waterproof brushless motor 1805, a thruster fixing base 1901, a horizontal propeller outer shell 1902, a horizontal propeller fixing hole 1903, a motor rotating shaft 1904, a 980kV waterproof brushless motor, an IPX8 waterproof servo 2001, a horizontal propeller fixing hole 2002, a horizontal propeller fixing bolt 2003, and a servo output shaft 2004. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It should be noted that the specific embodiments described herein are only for explanation and illustration of the present invention and are not intended to limit the present invention.

[0028] Example 1: Using Figs. 1-2 The following example illustrates the external structure of this underwater robot. Figs. 1-2The internal electronic sealing chamber of the robot is omitted to clearly illustrate the main structural components. The underwater robot includes a front shell 1, a rear shell 2, a legged walking mechanism 3, a vertical propeller thruster 4, and a horizontal propeller thruster 5. The front shell 1 and rear shell 2 are fixed together by internal connectors. The cable communication interface 6 is fixed to the tail of the main body by bolts. The left LED light 701, the right LED light 702, and the camera 8 are fixed to the head of the main body by bolts. The legged walking mechanism consists of six three-degree-of-freedom crawling legs, with the left front leg 901, right front leg 902, left middle leg 903, right middle leg 904, left hind leg 905, and right hind leg 906 symmetrically distributed on the outside of the robot body. The left front vertical thruster 1001, right front vertical thruster 1002, and rear vertical thruster 1003 are fixed to the robot body by bolts, while the left horizontal thruster 1101 and right horizontal thruster 1102 are fixed to the robot body by a base. The vector combination of the five thrusters enables multi-degree-of-freedom motion control of the robot in swimming mode. The robot mainly has three movement modes:

[0029] A. The six-legged crawling mode is suitable for delicate operation tasks such as exploration of complex seabed topography and equipment inspection and maintenance;

[0030] B. Hydrogel suction cup adhesion and crawling mode, suitable for near-wall operations such as hull cleaning and damage repair;

[0031] C. Propeller-driven mode, suitable for long-distance cruise and data acquisition tasks.

[0032] Example 2: Figs. 2-3 The following example illustrates the working principle of this underwater robot in crawling mode. When the host computer selects the six-legged crawling mode, the main controller, a Raspberry Pi, simulates biological neural rhythms through a central pattern generator based on a Hopf oscillator, outputting the target trajectories of the six legs. The six legs move by swinging the first joint 1201, adjusting the leg lift height with the second joint 1202, and maintaining foot translation with the third joint 1203. The Raspberry Pi calculates the 18 joint angles of the six legs in real time using inverse kinematics and converts these angles into the PWM duty cycle of the PCA9685, which is then controlled via the Raspberry Pi's GPIO I / O pins. 2 The C interface sends PWM register values ​​to the PCA9685. Based on the received duty cycle parameters, the PCA9685 outputs a 50Hz PWM signal to the corresponding servo motor. Utilizing the 16-channel PWM output, it controls 18 joints of six legs in parallel. 2 The C-bus batch writes to registers to reduce single communication latency. The body attitude is detected by the built-in inertial measurement unit, the joint angle of the support legs is adjusted to maintain balance, and the continuous crawling is achieved by continuously generating periodic signals based on the central mode generator.

[0033] Example 3: Using Figs. 3-4 The following example illustrates the working principle of this underwater robot in its adhesive crawling mode. When the host computer selects the adhesive crawling mode, the main controller, a Raspberry Pi, coordinates the six legs and hydrogel bionic suction cups to achieve adhesion and detachment during crawling. The diaphragm pump 15 provides negative pressure (evacuation during adsorption) and positive pressure (inflation during detachment). The hydrogel suction cup 16 achieves surface adhesion through negative pressure. The MOSFET drive module adjusts the start / stop and direction of the diaphragm pump. During the robot's crawling process, before the foot enters the support phase (ground contact and weight-bearing), the diaphragm pump is activated to evacuate the suction cups and apply negative pressure for adhesion. Before the foot enters the swing phase (leg lifting and movement), the diaphragm pump is switched to inflate the suction cups for detachment. The main controller, a Raspberry Pi, generates crawling gait signals and integrates them with the diaphragm pump's on / off signals, sending them to the slave controller. The slave controller's PCA9685 and MOSFETs drive in parallel, ensuring synchronous updates of the adhesion signals and joint PWM, achieving stable adhesion crawling on vertical or inverted surfaces.

[0034] Example 4: Figs. 5-7 The following example illustrates the working principle of this underwater robot in propeller-driven mode. When the host computer selects propeller-driven mode, the main controller Raspberry Pi generates control commands based on trajectory planning algorithms or upper-level inputs. It communicates with the flight controller via the MAVLink protocol, receives the main control commands from the flight controller, and parses them into motor speed commands. These commands are then parsed into digital signals by the electronic speed controller to control the brushless motor rotation. The brushless motor's rotating shaft 1802 is fixed with propeller blades to propel the robot. The robot adjusts its attitude and depth in real time using its built-in inertial measurement unit and depth sensor. The flight controller updates the motor speed every 20ms to dynamically adjust the robot's direction of motion. Multi-degree-of-freedom motion control is achieved through the vector combination of the five thrusters.

[0035] The above embodiments are merely illustrative of the inventive concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An underwater adherent robot with paddle leg hybrid drive, comprising a robot body, a six-legged crawling mechanism, a propeller propulsion system, a hydrogel biomimetic suction cup, an electronic sealed cabin and a sensing module, characterized in that: the robot body is externally symmetrical with six sets of leg crawling mechanisms, each set of leg crawling mechanism comprising three joint-driven mechanical legs, and the foot end is provided with a hydrogel biomimetic suction cup; the propeller system comprises three vertical propellers and two horizontal propellers, the vertical propellers are arranged on both sides of the front and rear of the robot body, and the horizontal propellers are arranged on both sides of the rear of the robot body; the electronic sealed cabin integrates a main controller, a slave controller and a power module, the main controller is a Raspberry Pi, used for multi-modal motion decision and trajectory planning; the slave controller includes a PCA9685 control board and a flight controller, respectively driving the leg servo and the propeller motor; the robot has the following three motion modes: six-legged crawling mode: a periodic gait is generated by a central pattern generator to control the leg joint servo to realize crawling operation; hydrogel suction cup adherent crawling mode: the negative pressure adsorption and desorption of the hydrogel biomimetic suction cup are controlled by a diaphragm pump to realize stable crawling on vertical or inverted surfaces in cooperation with the six-legged gait; propeller propulsion drive mode: vector combination of vertical and horizontal propeller propellers realizes multi-degree-of-freedom motion; The water gel biomimetic suction cup is prepared by digital light processing 3D printing of Zr 4 ⁺ coordination double network hydrogel, the suction cup is provided with a communication loop, and the adhesion and detachment functions are realized through air extraction and inflation of a diaphragm pump. The diaphragm pump is controlled by a MOSFET module, the suction action is synchronized with the phase of a six-legged gait, the support phase starts the adhesion, and the swing phase triggers the detachment. the sensing module includes an inertial measurement unit, a depth sensor and a foot end contact switch; the inertial measurement unit is used to feedback the robot attitude in real time, the depth sensor is used to measure the underwater depth of the robot, and the foot end contact switch is used to trigger the adsorption / desorption action; the robot head is provided with a 1080P high-definition camera and a double-LED searchlight, and the camera and the LED lamp are both sealed by epoxy resin casting; the tail of the robot is provided with a WF16-10 core waterproof communication interface supporting cable data transmission.

2. The underwater adherent robot of claim 1, wherein: The three joints of the six-legged crawling mechanism are 48mm, 76mm and 147mm in size, respectively, and each joint is driven by an IPX8 waterproof digital servo; a diaphragm pump is integrated inside the third joint, and waterproof sealing is realized by epoxy resin casting.

3. The underwater adherent robot of claim 1, wherein: The vertical propeller is driven by a 930kv brushless motor, and the upward / downward motion is realized by equal-speed same-direction rotation, and the pitch / roll motion is realized by equal-speed reverse rotation; the horizontal propeller is driven by a 980kv brushless motor, and the forward / backward motion is realized by equal-speed same-direction rotation, and the yaw motion is realized by differential rotation.

4. The underwater adherent robot of claim 1, wherein: The PCA9685 control board receives main controller instructions through I2C protocol and outputs 16-way PWM signals to drive 18 waterproof servos of six groups of legs; the flight controller receives main controller instructions through MAVLink protocol and analyzes them into motor speed signals, which are driven by an electronic speed regulator to drive the brushless motor.

5. A method of multi-modal motion control of an underwater adherent robot, the method comprising: The underwater adherent robot according to any one of claims 1-4 is realized, comprising the following steps: selecting a motion mode according to task requirements, generating corresponding control commands through a main controller Raspberry Pi; In the hexapod crawling mode, periodic gait signals are generated by the central pattern generator network and sent to the PCA9685 control board to drive the servo to execute the joint angles calculated by inverse kinematics in real time. In the adhesion crawling mode, the gait phase is synchronized with the diaphragm pump action, the support phase starts adsorption, the swing phase triggers desorption, and the body posture is adjusted in real time through the inertial measurement unit. In the propeller drive mode, the flight controller assigns the speed of each propeller, which is converted into a digital signal by the electronic speed controller to drive the brushless motor to rotate, achieving multi-degree-of-freedom motion control.

Images