An adaptive morphing amphibious multi-modal robotic system and control method

Abstract

The application discloses a kind of adaptive deformation's water-land multimode robot system and control method, including ontology, autopilot, power module, joint steering gear, wheel arm device, brushless drive motor, deformation drive steering gear, gear box and composite drive wheel.Autopilot and power module are installed in ontology interior;Joint steering gear is fixed in ontology four corners, connects wheel arm device;Gear box is fixed on wheel arm device, and wheel arm device is also provided with brushless drive motor and deformation drive steering gear;Composite drive wheel is fixed in gear box output shaft, inside has propeller, and composite drive wheel periphery is equipped with deformation block, and brushless drive motor controls drive wheel and propeller rotation.Deformation block is closed when underwater mode, propeller propels;Drive wheel drives when ground mode, deformation block unfolds and increases grip when encountering obstacle, and obstacle surmounting capacity is improved.The system structure is simple, environmental adaptability is strong, stability is good, and maneuverability is high, with multimode operation ability, applicable to complex and severe scene.

Description

Technical Field

[0001] This invention belongs to the field of cross-domain multimodal robot technology, and in particular relates to an adaptive deformation amphibious multimodal robot system and control method. Background Technology

[0002] In recent years, with the rapid development of robotics technology, humans have developed a variety of robots applicable to different spatial domains. However, most traditional robots are fixed in a single medium space and possess only a single motion mode, making it difficult to achieve complex cross-domain movements. This limitation is particularly evident in tasks such as multi-domain situational awareness, multi-dimensional information fusion, and cross-domain penetration attacks, severely restricting the robot's adaptability and task execution capabilities in varied and complex environments. For example, in fields such as disaster relief, resource exploration, and national defense, robots with a single motion mode often struggle to meet the demands of complex terrain and multi-medium environments. Therefore, researching cross-domain multimodal robots that can adapt to varied terrain environments and possess high maneuverability is of paramount importance.

[0003] Existing amphibious multimodal robots mainly consist of ground-based mechanisms and underwater propulsion mechanisms. Ground-based mechanisms typically employ wheeled, tracked, and legged designs, while underwater propulsion mechanisms generally utilize propeller propulsion, biomimetic propulsion, and water jet propulsion. However, most current amphibious multimodal robots simply add a drive wheel below the underwater propeller or add propellers to an unmanned vehicle. This design not only leads to redundancy in the power system but also suffers from high energy consumption and poor stability. Furthermore, most amphibious multimodal robots exhibit poor maneuverability in water, making them unsuitable for underwater environments with numerous obstacles. For example, existing technology has designed an amphibious robot with a propeller propeller mounted in the center of a four-wheeled chassis. The robot's wheels consist of multiple curved propeller blades that can converge into a circle or unfold into a windmill shape, but in practical applications, its maneuverability in water remains poor, its flexibility is insufficient, and the dispersed drive structure and redundancy in the power system persist.

[0004] In summary, while current amphibious robots possess amphibious mobility, they are generally unable to balance compact and simple configurations. Furthermore, they cannot adapt well to complex ground environments and struggle to handle tasks in complex and unknown scenarios such as rescue and search operations and environmental exploration. Summary of the Invention

[0005] This invention aims to address the shortcomings of existing technologies by proposing an adaptive, deformable, multimodal amphibious robot system and its control method. This robot possesses the ability to move on land and in water, and can autonomously switch its body state and operating mode according to different environments. It also features a compact and simple configuration design, enabling it to better adapt to complex environments and effectively handle multiple tasks.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] An adaptive deformable amphibious multimodal robot system includes a body, an autopilot, a power module, joint servo motors, a wheel-arm device, a brushless drive motor, a deformable drive servo motor, a gearbox, and a composite drive wheel;

[0008] The autopilot and power module are fixedly mounted on the main body; the joint servo motors are fixedly mounted at the four corners of the main body and connected to the wheel arm device to control the rotation of the wheel arm device; the brushless drive motor and the deformable drive servo motor are both fixedly mounted on the wheel arm device; the two ends of the gearbox are fixedly mounted on the wheel arm device, and there is a propeller inside; the compound drive wheel is fixedly mounted on the output end of the gearbox, and deformable blocks are installed on the periphery of the compound drive wheel.

[0009] The brushless drive motor is used to control the rotation of the propeller in the compound drive wheel and gearbox, while the morphing drive servo is used to control the deployment and closure of the morphing blocks. In underwater mode, the morphing drive servo controls the morphing blocks to close, and the underwater propulsion propeller generates driving force. In land mode, the compound drive wheel drives the vehicle, and when encountering obstacles, the morphing drive servo controls the morphing blocks to deploy, increasing the passability.

[0010] Preferably, the main body includes a cabin and a hatch, which together form a sealed cabin. The cabin contains an autopilot, a power module, and a joint servo motor. The main body acts as a structural skeleton, carrying and connecting other components.

[0011] Preferably, the articulated servo motors include a left front articulated servo motor, a right front articulated servo motor, a left rear articulated servo motor, and a right rear articulated servo motor, which are symmetrically installed in an X-shape at the corners of the body. The left front articulated servo motor and the right rear articulated servo motor are located on the same diagonal line, and the right front articulated servo motor and the left rear articulated servo motor are located on the same diagonal line. The left front articulated servo motor, the right front articulated servo motor, the left rear articulated servo motor, and the right rear articulated servo motor are all connected to a wheel arm device with identical structure. Each wheel arm device is fixedly installed with a brushless drive motor, a deformable drive servo motor, and a gearbox.

[0012] Preferably, the gearbox of the drive unit includes a gearbox cover, a drive gear shaft, a transmission gear, a propeller acceleration gear, a wheel reduction gear, a propeller gear shaft, a wheel gear shaft, and a deformable differential; wherein, the brushless drive motor transmits power to the drive gear shaft, the drive gear shaft meshes with the transmission gear, the transmission gear, the propeller acceleration gear, and the wheel reduction gear are coaxial and can rotate synchronously; the drive gear shaft also meshes with the differential gear disc of the deformable differential; the propeller acceleration gear meshes with the propeller gear shaft, thereby driving the propeller to rotate; the wheel reduction gear meshes with the wheel gear shaft, thereby driving the wheel to rotate; furthermore, the propeller gear shaft, the wheel gear shaft, and the deformable differential are coaxial, but they do not rotate synchronously.

[0013] Preferably, the deformable differential includes a fixed disc, a servo gear shaft, a primary reduction gear, a secondary reduction gear, a deformable output gear shaft, and a differential gear disc; wherein, the fixed disc is fixedly connected to the differential gear disc to fix the entire deformable differential; the power output of the deformable drive servo is sent to the servo gear shaft, which meshes with the primary reduction gear to achieve primary reduction; wherein, the primary reduction gear is symmetrically distributed on both sides of the servo gear shaft; the secondary reduction gear is symmetrically distributed on both sides of the deformable output gear shaft, the primary and secondary reduction gears are coaxial and can rotate synchronously; the secondary reduction gear meshes with the deformable output gear shaft to achieve secondary reduction; through the deformable differential, the power of the deformable drive servo can be transmitted through the deformable differential to achieve a four-fold reduction effect, and when the deformable drive servo is not in operation, the deformable output gear shaft can rotate synchronously with the wheel gear shaft.

[0014] Preferably, the composite drive wheel includes a wheel frame, deformable blocks, a propeller, a fixed shaft, a deformable drive gear, and an outer wheel frame; wherein, the wheel frame is connected and fixed to the drive gear shaft of the gearbox; six deformable blocks are evenly distributed around the circumference of the wheel frame, and their two ends are fixed by the wheel frame and the outer wheel frame respectively; the propeller is installed inside the composite drive wheel and connected and fixed to the propeller gear shaft of the gearbox; the fixed shaft is used to fix the wheel frame and the outer wheel frame; the deformable drive gear is connected and fixed to the deformable output gear shaft of the gearbox, and the deformable drive gear meshes with a gear on one side of the deformable block; the unfolding and closing of the deformable blocks directly affects the obstacle-crossing performance of the drive unit when moving on the ground.

[0015] Preferably, the autopilot includes an onboard computer and a data transmission module, a remote controller receiver, a pressure sensor, an IMU module, and a vision sensor connected to the onboard computer, wherein:

[0016] The IMU module is used to sense the position, attitude, and velocity of the amphibious multimodal robot system and send the position, attitude, and velocity information to the onboard computer.

[0017] Visual sensors are used to perceive the environment in front of the amphibious multimodal robot system and send the acquired image information to the onboard computer;

[0018] Pressure sensors are used to collect water pressure information of the amphibious multimodal robot system and send the collected load information to the onboard computer to calculate the water depth of the robot and determine the robot's environment.

[0019] The remote control receiver is used to receive control commands from the remote control transmitter and send the control commands to the onboard computer;

[0020] The onboard computer receives position, attitude, and velocity information, real-time position coordinates, image information, load information, and control commands from the amphibious multimodal robot system, and runs a preset control program to enable the amphibious multimodal robot system to operate under different driving modes.

[0021] The data transmission module is used to transmit the operational status information of the amphibious multimodal robot system in different modes to the ground control station.

[0022] Preferably, the driving modes include a ground mode and an underwater mode. In the ground mode, the joint servo drives the wheel arm device to rotate, keeping it in a horizontal position. The brushless drive motor drives the composite drive wheel to rotate, utilizing the friction between the wheel and the ground to provide driving force for the robot. In the underwater mode, the joint servo drives the wheel arm device to rotate, keeping it in a horizontal position. The propeller inside the composite drive wheel generates reverse thrust, thereby driving the robot. The ground mode also includes an obstacle-crossing mode and a non-obstacle-crossing mode. When the actuator enters the obstacle-crossing mode, the deformable drive servo rotates, driving the deformable drive gear of the composite drive wheel through the deformable differential in the gearbox, causing the deformable block to unfold. When the actuator switches from the obstacle-crossing mode to the non-obstacle-crossing mode, it controls the deformable drive servo to rotate, causing the deformable block to close, thus completing the mode transition.

[0023] A control method for an adaptive deformable amphibious multimodal robot, the method comprising the following steps:

[0024] S100: Set the starting point and ending point according to the task requirements, complete the path planning with time constraints and minimum energy consumption as the goals, place the water and land multimodal robot system at the starting point, divide the planned path into water navigation path and land movement path according to the road conditions, and store the designed control program and the divided water navigation path and land movement path in the autopilot.

[0025] S200: Sends corresponding operation mode commands according to the path of the amphibious multimodal robot system. The autopilot receives the operation mode commands and controls the brushless drive motor to drive the drive wheel and propeller to run along the predefined water navigation path or land movement path according to the control program.

[0026] S300: When the amphibious multimodal robot is running in land or underwater mode, it uses multiple sensors on the autopilot to perceive the surrounding environment in real time and transmits this information to the onboard computer. The onboard computer analyzes and judges the collected information to determine the specific environmental conditions of the robot, calculates the control coefficients based on the real-time status information, and selects the corresponding working mode. If a mode switch is required, it controls the robot to complete the mode switch.

[0027] S400: The autopilot acquires real-time status information of the amphibious multimodal robot system during operation after switching modes, calculates and adjusts control coefficients based on the real-time status information, and makes the real-time path close to the predefined water navigation path or land movement path.

[0028] S500: The autopilot acquires the real-time position of the amphibious multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the amphibious multimodal robot system has reached the destination and ends motion control.

[0029] Preferably, the control coefficients in S300 include lift coefficient, roll coefficient, yaw coefficient, and balance coefficient. The upper limit of these coefficients is 1, and the lower limit is 0. Specifically: the lift coefficient is used to adjust the lift provided by the motor to the amphibious multimodal robot system in water; the roll coefficient is used to adjust the roll torque provided by the motor to the amphibious multimodal robot system; the yaw coefficient is used to adjust the yaw torque provided by the motor to the amphibious multimodal robot system; and the balance coefficient is used to adjust the pitch torque provided by the motor to the amphibious multimodal robot system. S300 includes:

[0030] The amphibious multimodal robot collects the current environmental pressure through pressure sensors. If the pressure is below a set threshold, it indicates that the robot is in a land environment; if the pressure is above the set threshold, it indicates that the robot is in an underwater environment. When the robot is in a land environment, the lift coefficient is 0, the wheel-arm device is in a horizontal position, and the robot's support force is entirely provided by the ground; at this time, the robot is in land mode. When the robot is in an underwater environment, the lift coefficient gradually increases from 0 to 1, the wheel-arm device gradually changes from a horizontal position to a vertical position, and the robot's support force is jointly provided by the propeller and the ground; at this time, the robot is in mode switching. When the lift coefficient is 1, the wheel-arm device is in a vertical position, and the robot's support force is entirely provided by the propeller; at this time, the robot is in underwater mode.

[0031] The amphibious multimodal robot collects its actual yaw angle, roll angle, and pitch angle, as well as their corresponding yaw rate, roll rate, pitch rate, yaw acceleration, roll acceleration, and pitch acceleration, through an IMU module. When the amphibious multimodal robot is moving in water, the yaw coefficient, roll coefficient, and balance coefficient are all 0. If one or more of these parameters deviate from the target value, the amphibious multimodal robot is determined to be in a state of imminent instability in the water.

[0032] When the yaw angle of the amphibious multimodal robot deviates from the target value, PID calculations are performed based on the target yaw angle, the actual yaw angle, and the actual yaw rate to obtain the required yaw torque. The current yaw torque is normalized with the maximum yaw torque that the four propellers can provide as the upper limit to obtain the yaw coefficient, which is between 0 and 1. The robot is then controlled based on the calculated yaw coefficient to keep the yaw angle stable, thereby achieving stable movement of the robot in the water.

[0033] When the roll angle deviates from the target value, PID calculation is performed based on the target roll angle, the actual roll angle, and the actual roll velocity to obtain the required roll torque. The current roll torque is normalized with the maximum roll torque that the four propellers can provide as the upper limit to obtain the roll coefficient, which is between 0 and 1. The robot is controlled according to the calculated roll coefficient to keep the roll angle stable, thereby achieving stable movement of the robot in the water.

[0034] When the pitch angle deviates from the target value, PID calculation is performed based on the target pitch angle, the actual pitch angle, and the actual pitch velocity to obtain the required pitch torque. The current pitch torque is normalized using the maximum pitch torque that the four propellers can provide as the upper limit to obtain the pitch coefficient, which is between 0 and 1. The robot is then controlled based on the calculated pitch coefficient to keep the pitch angle stable, thereby achieving stable movement of the robot in the water.

[0035] When the amphibious multimodal robot is in ground movement mode, it collects image information of the road conditions ahead through visual sensors. If the image information shows that there are obstacles on the ground ahead, the robot switches to obstacle-crossing mode to enhance its ability to pass through obstacles. If the image information shows that the ground ahead is flat and unobstructed, the robot switches to non-obstruction-crossing mode to increase its speed.

[0036] The aforementioned adaptive deformable amphibious multimodal robot system features a clever deformation design and excellent robot maneuverability. The robot employs a composite drive wheel design, integrating a ground drive mechanism and an underwater drive propeller. Simultaneously, the robot controls the direction of the wheel arm device via joint servos, enabling flexible switching between two motion modes. Compared to existing amphibious multimodal robots that suffer from insufficient flexibility due to dispersed drive structures and redundant power components, this invention effectively reduces power component redundancy through a centralized drive structure, thereby improving the robot's flexibility. It exhibits strong environmental adaptability, capable of handling tasks in various scenarios. On flat ground, the robot operates in non-obstacle-crossing ground mode with a relatively fast travel speed; when encountering obstacles or special terrain, it can switch to obstacle-crossing mode, allowing the robot to successfully traverse complex environments. In water, the robot operates in underwater mode, possessing cross-domain multimodal operation capabilities, effectively meeting the task requirements in various environments. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of an adaptive deformable amphibious multimodal robot system in a non-obstacle-crossing mode in ground mode, according to an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the obstacle-crossing mode of an adaptive deformation amphibious multimodal robot system in one embodiment of the present invention.

[0039] Figure 3 This is a schematic diagram of the structure of an adaptive deformation amphibious multimodal robot system in underwater mode according to an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram of the gearbox structure in one embodiment of the present invention;

[0041] Figure 5 This is a schematic diagram of the composite drive wheel in one embodiment of the present invention;

[0042] Figure 6 This is a schematic block diagram of the structure of an autopilot in one embodiment of the present invention;

[0043] Figure 7 This is a flowchart of a motion control method for an adaptive deformation multimodal amphibious robot system according to an embodiment of the present invention;

[0044] Explanation of reference numerals in the attached figures:

[0045] 10. Main body; 11. Hull; 12. Hood; 20. Autopilot; 30. Power module; 40. Joint servo; 41. Front left joint servo; 42. Front right joint servo; 43. Rear left joint servo; 44. Rear right joint servo; 50. Wheel arm assembly; 60. Brushless drive motor; 70. Deformation drive servo; 80. Gearbox; 81. Gearbox cover; 82. Drive gear shaft; 83. Transmission gear; 84. Propeller acceleration gear; 85. 86. Wheel reduction gear; 87. Propeller gear shaft; 88. Wheel gear shaft; 89. Deformable differential; 801. Fixed disc; 802. Servo gear shaft; 803. First-stage reduction gear; 804. Second-stage reduction gear; 805. Deformable output gear shaft; 806. Differential gear disc; 90. Compound drive wheel; 91. Wheel frame; 92. Deformable block; 93. Propeller; 94. Fixed shaft; 95. Deformable drive gear; 96. Outer wheel frame. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] See Figure 1. Figure 2 and Figure 3 , Figure 1 and Figure 2 This is a schematic diagram of the structure of an adaptive deformable amphibious multimodal robot system of the present invention in both non-obstacle-crossing mode and obstacle-crossing mode in ground mode. Figure 3 This is a schematic diagram of the underwater mode of an adaptive deformation multimodal robot system for amphibious and land use according to the present invention.

[0048] In one embodiment, an adaptive deformable amphibious multimodal robot system includes a body 10, an autopilot 20, a power module 30, a joint servo motor 40, a wheel-arm device 50, a brushless drive motor 60, a deformable drive servo motor 70, a gearbox 80, and a composite drive wheel 90.

[0049] The autopilot 20 and power module 30 are fixedly mounted on the main body 10; the joint servo motor 40 is fixedly mounted on the four corners of the main body 10 and connected to the wheel arm device 50 to control the rotation of the wheel arm device 50; the brushless drive motor 60 and the deformable drive servo motor 70 are both fixedly mounted on the wheel arm device 50; the two ends of the gearbox 80 are fixedly mounted on the wheel arm device 50, and there is a propeller inside; the compound drive wheel 90 is fixedly mounted on the output end of the gearbox 80, and deformable blocks are installed on the periphery of the compound drive wheel 90.

[0050] The brushless drive motor 60 controls the rotation of the propeller in the compound drive wheel 90 and gearbox 80, while the morphing drive servo 70 controls the deployment and closure of the morphing blocks. In underwater mode, the morphing drive servo 70 controls the morphing blocks to close, generating driving force through the underwater propulsion propeller. In ground mode, the compound drive wheel 90 provides propulsion, and when encountering large obstacles, the morphing drive servo 70 controls the morphing blocks to deploy, increasing traction.

[0051] In one embodiment, the body 10 includes a cabin 11 and a hatch 12, which together form a sealed cabin. The cabin 11 is equipped with an autopilot 20, a power module 30, and a joint servo motor 40. The body 10 acts as a structural skeleton, carrying and connecting other components.

[0052] In one embodiment, the joint servo motors 40 include a left front joint servo motor 41, a right front joint servo motor 42, a left rear joint servo motor 43, and a right rear joint servo motor 44, which are symmetrically mounted in an X-shape at the corners of the body 10. The left front joint servo motor 41 and the right rear joint servo motor 44 are located on the same diagonal line, as are the right front joint servo motor 42 and the left rear joint servo motor 43. Each of the four joint servo motors 41, 42, 43, and 44 is connected to a wheel-arm assembly 50 with an identical structure. Each wheel-arm assembly 50 is fixedly mounted with a brushless drive motor 60, a deformable drive servo motor 70, and a gearbox 80. The four wheel-arm assemblies constitute a four-wheel drive system, which provides the robot with better safety, stability, and high maneuverability in both ground and underwater modes. It also provides greater traction and grip, and improves load-bearing capacity and obstacle-crossing ability.

[0053] In one embodiment, see Figure 4 The drive gearbox 80 includes a gearbox cover 81, a drive gear shaft 82, a transmission gear 83, a propeller acceleration gear 84, a wheel reduction gear 85, a propeller gear shaft 86, a wheel gear shaft 87, and a deformable differential 88. The brushless drive motor 60 transmits power to the drive gear shaft 82, which meshes with the transmission gear 83. The transmission gear 83, propeller acceleration gear 84, and wheel reduction gear 85 are coaxial and can rotate synchronously. The drive gear shaft 82 also meshes with the differential gear disc 806 of the deformable differential 88. The propeller acceleration gear 84 meshes with the propeller gear shaft 86, thereby driving the propeller to rotate. The wheel reduction gear 85 meshes with the wheel gear shaft 87, thereby driving the wheel to rotate. Furthermore, while the propeller gear shaft 86, wheel gear shaft 87, and deformable differential 88 are coaxial, they do not rotate synchronously.

[0054] Specifically, the drive gear shaft 82 is rigidly connected to the brushless drive motor 60 via a coupling. Power is transmitted to the propeller acceleration gear 84 and the wheel reduction gear 85 via the drive gear shaft 82 and the transmission gear 83, respectively. Since the driving force for the robot's underwater propulsion and land walking both come from the brushless drive motor, and the propeller needs to rotate at high speed while the wheel speed is relatively low, in this invention, the gear ratio between the propeller acceleration gear 84 and the propeller gear shaft 86 is 2:1, and the propeller gear shaft 86 is directly connected to the propeller 93 inside the compound drive wheel 90, thereby achieving a twofold acceleration of the propeller 93; the gear ratio between the wheel reduction gear 85 and the wheel gear shaft 87 is 1:4, and the wheel gear shaft 87 is directly connected to the wheel frame 91 of the compound drive wheel 90, thereby achieving a fourfold reduction of the wheel speed.

[0055] In one embodiment, the deformable differential 88 includes a fixed plate 801, a servo gear shaft 802, a first-stage reduction gear 803, a second-stage reduction gear 804, a deformable output gear shaft 805, and a differential gear disk 806; wherein, the fixed plate 801 is fixedly connected to the differential gear disk 806 to fix the entire deformable differential 88; the power output of the deformable drive servo 70 is sent to the servo gear shaft 802, and the servo gear shaft 802 meshes with the first-stage reduction gear 803 to achieve first-stage reduction; wherein, the first-stage reduction gear 803 is symmetrically distributed on the servo gear shaft. On both sides of 802; the secondary reduction gear 804 is symmetrically distributed on both sides of the deformable output gear shaft 805. The primary reduction gear 803 and the secondary reduction gear 804 are coaxial and can rotate synchronously. The secondary reduction gear 804 meshes with the deformable output gear shaft 805 to achieve secondary reduction. Through the deformable differential 88, the power of the deformable drive servo 70 can be transmitted through the deformable differential 88 to achieve a four-fold reduction effect. When the deformable drive servo 70 is not working, the deformable output gear shaft 805 can rotate synchronously with the wheel gear shaft 87.

[0056] To enable the expansion and contraction of the deformable block 92 in the composite drive wheel 90, a deformable drive servo motor 70 is required. However, the deformable block 92 rotates synchronously with the wheel, while the deformable drive servo motor 70 is fixed to the wheel arm assembly 50. Therefore, the input to the deformable drive servo motor 70 must be transmitted through the deformable differential 88 to ensure that when the deformable drive servo motor 70 is stationary, the deformable output gear shaft 805 can rotate synchronously with the wheel gear shaft 87; and when the deformable drive servo motor 70 is operating, power superposition can be achieved. Specifically, the gear ratio between the differential gear disk 806 and the transmission gear 83 is 1:3, and the two-stage reducer inside the deformable differential 88 can achieve a four-fold reduction effect. For example, when the transmission gear 83 rotates clockwise 12 times, the wheel gear shaft 87 rotates counterclockwise 3 times, and the differential gear disk 806 rotates counterclockwise 4 times. Since the deformable drive servo 70 is stationary, its input end, relative to the differential gear disk 806, is equivalent to rotating clockwise 4 times. After two stages of reduction, the deformable output gear shaft 805 rotates clockwise 1 time relative to the differential gear disk 806. Because the differential gear disk 806 rotates counterclockwise 4 times relative to the whole system, the deformable output gear shaft 805 ultimately rotates counterclockwise 3 times relative to the whole system, keeping synchronized with the rotation of the wheel gear shaft 87. In this way, when the deformable drive servo 70 is not working, the deformable output gear shaft 805 can rotate with the wheel, thus ensuring that the deformable block 92 will not accidentally unfold or close due to the rotation of the wheel.

[0057] In one embodiment, see Figure 5 The compound drive wheel 90 includes a wheel frame 91, deformable blocks 92, a propeller 93, a fixed shaft 94, a deformable drive gear 95, and an outer wheel frame 96. The wheel frame 91 is connected and fixed to the drive gear shaft 82 of the gearbox 80. Six deformable blocks 92 are evenly distributed circumferentially along the wheel frame 91, with their ends fixed to the wheel frame 91 and the outer wheel frame 96, respectively. The propeller 93 is installed inside the compound drive wheel 90 and connected and fixed to the propeller gear shaft 86 of the gearbox 80. The fixed shaft 94 is used to fix the wheel frame 91 and the outer wheel frame 96. The deformable drive gear 95 is connected and fixed to the deformable output gear shaft 805 of the gearbox 80, and simultaneously meshes with a gear on one side of the deformable block 92. The unfolding and closing of the deformable block 92 directly affects the obstacle-crossing performance of the drive unit when moving on the ground.

[0058] Specifically, in a land environment, the wheel frame 91, the deformable block 92, and the outer wheel frame 96 form an integral structure, and the friction between this structure and the ground provides the robot with driving force. When the robot is in an underwater environment, the driving force is generated by the propeller 93 located in the middle. Under the drive of the deformable drive servo 70, the deformable drive gear 95 can cause the deformable block 92 to extend outward, thereby increasing the robot's grip and significantly improving its obstacle-crossing ability.

[0059] In one embodiment, the driving modes include a ground mode and an underwater mode. In the ground mode, the articulated servo motor 40 drives the wheel arm assembly 50 to rotate, keeping it in a horizontal position. The brushless drive motor 60 drives the composite drive wheel 90 to rotate, utilizing the friction between the wheel and the ground to provide driving force for the robot. In the underwater mode, the articulated servo motor 40 drives the wheel arm assembly 50 to rotate, keeping it in a horizontal position. The propeller 93 inside the composite drive wheel 90 generates reverse thrust, thereby driving the robot. The ground mode also includes an obstacle-crossing mode and a non-obstacle-crossing mode. When the actuator enters the obstacle-crossing mode, the deformable drive servo motor 70 rotates, driving the deformable drive gear 95 of the composite drive wheel 90 through the deformable differential 88 in the gearbox 80, causing the deformable block 92 to unfold. The unfolding of the deformable block 92 increases grip, significantly improving the actuator's obstacle-crossing capability. When the actuator switches from the obstacle-crossing mode to the non-obstacle-crossing mode, it controls the deformable drive servo motor 70 to rotate, causing the deformable block 92 to close, thus completing the mode transition.

[0060] In one embodiment, see Figure 6 The autopilot 20 includes an onboard computer and a data transmission module connected to the onboard computer, a remote control receiver, a pressure sensor, an IMU module, and a vision sensor, wherein:

[0061] The IMU module is used to sense the position, attitude, and velocity of the amphibious multimodal robot system and send the position, attitude, and velocity information to the onboard computer.

[0062] Visual sensors are used to perceive the environment in front of the amphibious multimodal robot system and send the acquired image information to the onboard computer;

[0063] Pressure sensors are used to collect water pressure information of the amphibious multimodal robot system and send the collected load information to the onboard computer to calculate the water depth of the robot and determine the robot's environment.

[0064] The remote control receiver is used to receive control commands from the remote control transmitter and send the control commands to the onboard computer;

[0065] The onboard computer receives position, attitude, and velocity information, real-time position coordinates, image information, load information, and control commands from the amphibious multimodal robot system, and runs a preset control program to enable the amphibious multimodal robot system to operate under different driving modes.

[0066] The data transmission module is used to transmit the operational status information of the amphibious multimodal robot system in different modes to the ground control station.

[0067] Specifically, pressure sensors determine the robot's environment by measuring the surrounding pressure. In a terrestrial environment, the pressure primarily comes from atmospheric pressure; while in an underwater environment, the pressure mainly comes from water pressure, and the pressure varies at different depths. Based on this characteristic, pressure sensors can be used to calculate the water depth of the robot and control it to perform mode switching accordingly. It should be noted that the ground control station is a communication tool and is not part of the aforementioned terrestrial and amphibious multimodal robot system.

[0068] In one embodiment, see Figure 7 A control method for an adaptive deformation-adaptive amphibious multimodal robot, the method comprising the following steps:

[0069] S100: Set the starting point and ending point according to the task requirements, complete the path planning with time constraints and minimum energy consumption as the goals, place the water and land multimodal robot system at the starting point, divide the planned path into water navigation path and land movement path according to the road conditions, and store the designed control program and the divided water navigation path and land movement path in the autopilot.

[0070] Specifically, the control program encompasses a geometry controller in underwater mode and a motion controller in land-based motion mode. Based on the specific requirements and nature of the mission, a start and end point are set, and the time required to complete the mission is used as a constraint, with minimizing overall energy consumption as the optimization objective for path planning. Subsequently, the planned path is divided into an underwater navigation path and a land-based motion path based on road conditions. Existing geometry and motion controllers can be used, and they, along with the divided underwater navigation and land-based motion paths, are stored in the autopilot.

[0071] S200: Sends corresponding operation mode commands according to the path of the amphibious multimodal robot system. The autopilot receives the operation mode commands and controls the brushless drive motor to drive the drive wheel and propeller to run along the predefined water navigation path or land movement path according to the control program.

[0072] Specifically, the operational modal commands include underwater navigation commands and ground movement commands. When executing an underwater navigation command, the amphibious multimodal robot system switches to underwater navigation mode, controlling its navigation in the water using a designed geometric controller. When executing a ground movement command, the system switches to land movement mode, controlling its movement on land using a designed motion controller.

[0073] S300: When the amphibious multimodal robot is running in either ground or underwater mode, it uses multiple sensors on its autopilot to perceive the surrounding environment in real time and transmits this information to the onboard computer. The onboard computer analyzes and judges the collected information to determine the specific environmental conditions of the robot, calculates control coefficients based on real-time status information, and selects the appropriate operating mode. If a mode switch is required, it controls the robot to complete the mode switch.

[0074] Specifically, the control coefficients include lift coefficient, roll coefficient, yaw coefficient, and balance coefficient. The upper limit of these coefficients is 1, and the lower limit is 0. Specifically: the lift coefficient adjusts the lift provided by the motors to the amphibious multimodal robot system in water; the roll coefficient adjusts the roll torque provided by the motors; the yaw coefficient adjusts the yaw torque provided by the motors; and the balance coefficient adjusts the pitch torque provided by the motors.

[0075] The amphibious multimodal robot collects the current environmental pressure through pressure sensors. If the pressure is below a set threshold, it indicates that the robot is in a land environment; if the pressure is above the set threshold, it indicates that the robot is in an underwater environment. When the robot is in a land environment, the lift coefficient is 0, the wheel-arm assembly is in a horizontal position, and the robot's support force is entirely provided by the ground; at this time, the robot is in land mode. When the robot is in an underwater environment, the lift coefficient gradually increases from 0 to 1, the wheel-arm assembly gradually changes from a horizontal position to a vertical position, and the robot's support force is jointly provided by the propeller and the ground; at this time, the robot is in mode switching. When the lift coefficient is 1, the wheel-arm assembly is in a vertical position, and the robot's support force is entirely provided by the propeller; at this time, the robot is in underwater mode.

[0076] The amphibious multimodal robot uses an IMU module to collect its actual yaw angle, roll angle, and pitch angle, along with their corresponding yaw rate, roll rate, pitch rate, yaw acceleration, roll acceleration, and pitch acceleration. When the amphibious multimodal robot is moving in water, its yaw coefficient, roll coefficient, and balance coefficient are all 0. If one or more of these parameters deviate from the target value, the amphibious multimodal robot is determined to be in a state of imminent instability in the water.

[0077] When the yaw angle of the amphibious multimodal robot deviates from the target value, PID calculations are performed based on the target yaw angle, the actual yaw angle, and the actual yaw rate to obtain the required yaw torque. The current yaw torque is normalized using the maximum yaw torque that the four propellers can provide as an upper limit, resulting in a yaw coefficient between 0 and 1. The robot is then controlled based on this calculated yaw coefficient to maintain a stable yaw angle, thereby achieving stable movement in the water.

[0078] When the roll angle deviates from the target value, a PID calculation is performed based on the target roll angle, the actual roll angle, and the actual roll velocity to obtain the required roll torque. The current roll torque is normalized using the maximum roll torque that the four propellers can provide as an upper limit, resulting in a roll coefficient between 0 and 1. The robot is then controlled based on this calculated roll coefficient to maintain a stable roll angle, thereby achieving stable movement in the water.

[0079] When the robot's pitch angle deviates from the target value, a PID calculation is performed based on the target pitch angle, the actual pitch angle, and the actual pitch velocity to obtain the required pitch torque. The current pitch torque is normalized using the maximum pitch torque that the four propellers can provide as an upper limit, resulting in a pitch coefficient between 0 and 1. The robot is then controlled according to this calculated pitch coefficient to maintain a stable pitch angle, thereby achieving stable movement in the water.

[0080] When the amphibious multimodal robot is in ground movement mode, it collects image information about the road conditions ahead through visual sensors. If the image information shows that there are large obstacles on the ground ahead, the robot switches to obstacle-crossing mode to enhance its ability to pass through obstacles; if the image information shows that the ground ahead is flat and unobstructed, the robot switches to non-obstruction-crossing mode to increase its travel speed.

[0081] S400: The autopilot acquires real-time status information of the amphibious multimodal robot system during operation after switching modes, calculates and adjusts control coefficients based on the real-time status information, and makes the real-time path close to the predefined water navigation path or land movement path.

[0082] Specifically, when adjusting the control coefficient, the adjustment variable of the control coefficient changes in a direct proportion.

[0083] S500: The autopilot acquires the real-time position of the amphibious multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the amphibious multimodal robot system has reached the destination and ends motion control.

[0084] The aforementioned multimodal robot system can autonomously switch operating modes according to the actual environment, achieving efficient operation in both underwater and terrestrial environments. Its composite drive wheels integrate a dual-drive mechanism for both water and land, resulting in a compact structure and excellent obstacle-crossing capabilities, significantly enhancing its environmental adaptability. Furthermore, the robot possesses outstanding stability and multimodal operation capabilities, enabling it to meet the task requirements of various complex scenarios.

[0085] The above provides a detailed description of an adaptive deformation-modal amphibious robot system and control method provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention; the descriptions of these embodiments are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An adaptive deformation multimodal amphibious robot system, characterized in that, It includes the main body, autopilot, power module, joint servo, wheel arm device, brushless drive motor, deformable drive servo, gearbox and composite drive wheel; The autopilot and power module are fixedly mounted on the main body; the joint servo motors are fixedly mounted on the four corners of the main body and connected to the wheel arm device to control the rotation of the wheel arm device; the brushless drive motor and the deformable drive servo motor are both fixedly mounted on the wheel arm device; the two ends of the gearbox are fixedly mounted on the wheel arm device, and there is a propeller inside. The compound drive wheel is mounted and fixed on the output end of the gearbox, and deformable blocks are installed around the compound drive wheel; The brushless drive motor is used to control the rotation of the propeller in the compound drive wheel and gearbox, while the morphing drive servo is used to control the deployment and closure of the morphing blocks. In underwater mode, the morphing drive servo controls the morphing blocks to close, and the underwater propulsion propeller generates driving force. In land mode, the compound drive wheel drives the vehicle, and when encountering obstacles, the morphing drive servo controls the morphing blocks to deploy, increasing the passability. The main body includes a cabin and a canopy. The cabin contains an autopilot, a power module, and joint servos. The joint servos include a left front joint servo, a right front joint servo, a left rear joint servo, and a right rear joint servo, which are symmetrically installed in an X-shape at the corners of the main body. The left front joint servo and the right rear joint servo are located on the same diagonal line, and the right front joint servo and the left rear joint servo are located on the same diagonal line. The left front joint servo, the right front joint servo, the left rear joint servo, and the right rear joint servo are all connected to a wheel arm device with an identical structure. Each wheel arm device is fixedly installed with a brushless drive motor, a deformable drive servo, and a gearbox. The drive gearbox includes a gearbox cover, a drive gear shaft, transmission gears, a propeller acceleration gear, a wheel reduction gear, a propeller gear shaft, a wheel gear shaft, and a deformable differential. A brushless drive motor transmits power to the drive gear shaft, which meshes with the transmission gear. The transmission gear, propeller acceleration gear, and wheel reduction gear are coaxial and rotate synchronously. The drive gear shaft also meshes with the differential gear disc of the deformable differential. The propeller acceleration gear meshes with the propeller gear shaft, driving the propeller to rotate. The wheel reduction gear meshes with the wheel gear shaft, driving the wheels to rotate. Furthermore, while the propeller gear shaft, wheel gear shaft, and deformable differential are coaxial, they do not rotate synchronously. The deformable differential includes a fixed disc, a servo gear shaft, a primary reduction gear, a secondary reduction gear, a deformable output gear shaft, and a differential gear disc. The fixed disc is fixedly connected to the differential gear disc to secure the entire deformable differential. The power output of the deformable servo is sent to the servo gear shaft, which meshes with the primary reduction gear to achieve primary reduction. The primary reduction gears are symmetrically distributed on both sides of the servo gear shaft. The secondary reduction gears are symmetrically distributed on both sides of the deformable output gear shaft, and the primary and secondary reduction gears are coaxial and can rotate synchronously. The secondary reduction gears mesh with the deformable output gear shaft to achieve secondary reduction. Through the deformable differential, the power of the deformable servo can be transmitted, achieving a four-fold reduction effect. When the deformable servo is not in operation, the deformable output gear shaft can rotate synchronously with the wheel gear shaft.

2. The system according to claim 1, characterized in that, The hull and hatch together form a sealed cabin, with the main body acting as the structural skeleton, carrying and connecting other components.

3. The system according to claim 2, characterized in that, The compound drive wheel includes a wheel frame, deformable blocks, a propeller, a fixed shaft, a deformable drive gear, and an outer wheel frame. The wheel frame is fixedly connected to the drive gear shaft of the gearbox. Six deformable blocks are evenly distributed around the circumference of the wheel frame, with both ends fixed to the wheel frame and the outer wheel frame, respectively. The propeller is installed inside the compound drive wheel and fixedly connected to the propeller gear shaft of the gearbox. The fixed shaft is used to fix the wheel frame and the outer wheel frame. The deformable drive gear is fixedly connected to the deformable output gear shaft of the gearbox, and simultaneously meshes with a gear on one side of the deformable block. The deployment and closure of the deformable blocks directly affect the obstacle-crossing performance of the drive unit when moving on the ground.

4. The system according to claim 3, characterized in that, The autopilot includes an onboard computer and a data transmission module connected to the onboard computer, a remote controller receiver, a pressure sensor, an IMU module, and a vision sensor, among which: The IMU module is used to sense the position, attitude, and velocity of the amphibious multimodal robot system and send the position, attitude, and velocity information to the onboard computer. Visual sensors are used to perceive the environment in front of the amphibious multimodal robot system and send the acquired image information to the onboard computer; Pressure sensors are used to collect water pressure information of the amphibious multimodal robot system and send the collected load information to the onboard computer to calculate the water depth of the robot and determine the robot's environment. The remote control receiver is used to receive control commands from the remote control transmitter and send the control commands to the onboard computer; The onboard computer receives position, attitude, and velocity information, real-time position coordinates, image information, load information, and control commands from the amphibious multimodal robot system, and runs a preset control program to enable the amphibious multimodal robot system to operate under different driving modes. The data transmission module is used to transmit the operational status information of the amphibious multimodal robot system in different modes to the ground control station.

5. The system according to claim 4, characterized in that, The driving modes include ground mode and underwater mode. In ground mode, the articulated servo drives the wheel arm device to rotate, keeping it in a horizontal position. The brushless drive motor drives the composite drive wheel to rotate, using the friction between the wheel and the ground to provide driving force for the robot. In underwater mode, the articulated servo drives the wheel arm device to rotate, keeping it in a horizontal position. The propeller inside the composite drive wheel generates thrust, thereby driving the robot. The ground mode also includes obstacle-crossing mode and non-obstacle-crossing mode. When the actuator enters obstacle-crossing mode, the deformable drive servo rotates, driving the deformable drive gear of the composite drive wheel through the deformable differential in the gearbox, causing the deformable blocks to unfold. When the driver switches from obstacle-crossing mode to non-obstacle-crossing mode, it controls the deformation drive servo to rotate, causing the deformation block to close, thus completing the mode switch.

6. A control method for an adaptive deformation amphibious multimodal robot system as described in any one of claims 1 to 5, characterized in that, The method includes the following steps: S100: Set the starting point and ending point according to the task requirements, complete the path planning with time constraints and minimum energy consumption as the goals, place the water and land multimodal robot system at the starting point, divide the planned path into water navigation path and land movement path according to the road conditions, and store the designed control program and the divided water navigation path and land movement path in the autopilot. S200: Sends corresponding operation mode commands according to the path of the amphibious multimodal robot system. The autopilot receives the operation mode commands and controls the brushless drive motor to drive the drive wheel and propeller to run along the predefined water navigation path or land movement path according to the control program. S300: When the amphibious multimodal robot is running in land or underwater mode, it uses multiple sensors on the autopilot to perceive the surrounding environment in real time and transmits this information to the onboard computer. The onboard computer analyzes and judges the collected information to determine the specific environmental conditions of the robot, calculates the control coefficients based on the real-time status information, and selects the corresponding working mode. If a mode switch is required, it controls the robot to complete the mode switch. S400: The autopilot acquires real-time status information of the amphibious multimodal robot system during operation after switching modes, calculates and adjusts control coefficients based on the real-time status information, and makes the real-time path close to the predefined water navigation path or land movement path. S500: The autopilot acquires the real-time position of the amphibious multimodal robot system, compares the real-time position with the destination position, and if the real-time position is near the destination position, it determines that the amphibious multimodal robot system has reached the destination and ends motion control.

7. The method according to claim 6, characterized in that, The control coefficients in S300 include lift coefficient, roll coefficient, yaw coefficient, and balance coefficient. The upper limit of these coefficients is 1, and the lower limit is 0. Specifically: the lift coefficient adjusts the lift provided by the motors to the amphibious multimodal robot system in water; the roll coefficient adjusts the roll torque provided by the motors; the yaw coefficient adjusts the yaw torque provided by the motors; and the balance coefficient adjusts the pitch torque provided by the motors. S300 includes: The amphibious multimodal robot collects the current environmental pressure through pressure sensors. If the pressure is below a set threshold, it indicates that the robot is in a land environment; if the pressure is above the set threshold, it indicates that the robot is in an underwater environment. When the robot is in a land environment, the lift coefficient is 0, the wheel-arm device is in a horizontal position, and the robot's support force is entirely provided by the ground; at this time, the robot is in land mode. When the robot is in an underwater environment, the lift coefficient gradually increases from 0 to 1, the wheel-arm device gradually changes from a horizontal position to a vertical position, and the robot's support force is jointly provided by the propeller and the ground; at this time, the robot is in mode switching. When the lift coefficient is 1, the wheel-arm device is in a vertical position, and the robot's support force is entirely provided by the propeller; at this time, the robot is in underwater mode. The amphibious multimodal robot collects its actual yaw angle, roll angle, and pitch angle, as well as their corresponding yaw rate, roll rate, pitch rate, yaw acceleration, roll acceleration, and pitch acceleration, through an IMU module. When the amphibious multimodal robot is moving in water, the yaw coefficient, roll coefficient, and balance coefficient are all 0. If one or more of these parameters deviate from the target value, the amphibious multimodal robot is determined to be in a state of imminent instability in the water. When the yaw angle of the amphibious multimodal robot deviates from the target value, PID calculations are performed based on the target yaw angle, the actual yaw angle, and the actual yaw rate to obtain the required yaw torque. The current yaw torque is normalized with the maximum yaw torque that the four propellers can provide as the upper limit to obtain the yaw coefficient, which is between 0 and 1. The robot is then controlled based on the calculated yaw coefficient to keep the yaw angle stable, thereby achieving stable movement of the robot in the water. When the roll angle deviates from the target value, PID calculation is performed based on the target roll angle, the actual roll angle, and the actual roll velocity to obtain the required roll torque. The current roll torque is normalized with the maximum roll torque that the four propellers can provide as the upper limit to obtain the roll coefficient, which is between 0 and 1. The robot is controlled according to the calculated roll coefficient to keep the roll angle stable, thereby achieving stable movement of the robot in the water. When the pitch angle deviates from the target value, PID calculations are performed based on the target pitch angle, the actual pitch angle, and the actual pitch velocity to obtain the required pitch torque. The current pitch torque is normalized using the maximum pitch torque that the four propellers can provide as the upper limit to obtain the pitch coefficient, which is between 0 and 1. The robot is then controlled based on the calculated pitch coefficient to keep the pitch angle stable, thereby achieving stable movement of the robot in the water. When the amphibious multimodal robot is in ground movement mode, it collects image information of the road conditions ahead through visual sensors. If the image information shows that there are obstacles on the ground ahead, the robot switches to obstacle-crossing mode to enhance its ability to pass through obstacles. If the image information shows that the ground ahead is flat and unobstructed, the robot switches to non-obstruction-crossing mode to increase its speed.

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