A multi-mode multi-form multi-environment robot

Abstract

The application discloses a multi-mode multi-form multi-habitat robot. The hip joint of the robot is a single-side three-degree-of-freedom structure, and a wheel / point switching lower limb can be driven to complete actions such as lifting, swinging and turning, thereby providing necessary movement degrees of freedom for a double-wheel foot and a double-point foot form. A head is provided with a balance wheel assembly, which works as a driving wheel set in a four-wheel form and constitutes a balance car form when independently driven. The wheel / point switching lower limb is provided with a wheel set and a driving mechanism which can move along a leg guide rail, the wheel set is grounded when moving downward, thereby forming a double-wheel foot form, and the wheel set is grounded when being retracted, thereby forming a double-point foot form, and the switching process is automatically completed by an executing mechanism without manual disassembly. An expandable spoke wheel assembly can be used as a grounding wheel set and a double-wheel foot to form a three-wheel form on land, and can act as a fulcrum when the double-wheel foot and the double-point foot form are switched, and after being expanded and turned, the underwater propulsion mechanism is formed. The application has multi-habitat mobility in different environments such as land, water surface and underwater.

Description

Technical Field

[0001] This invention belongs to the field of mobile robots, specifically relating to a multi-mode, multi-form amphibious robot. Background Technology

[0002] Mobile robots, when performing field reconnaissance, search and rescue, and transportation missions, need to maneuver in continuously changing environments such as land, shallow water, and water, which places high demands on the platform's cross-medium adaptability. To balance the efficiency of wheeled mobility with the obstacle-crossing ability of legged mobility, existing technologies have developed various wheel-leg hybrid configurations. However, these all have specific structural and functional limitations in practical applications: For schemes that mount independent drive wheels and fixed feet side-by-side at the ends of the lower legs, the choice between wheel rim contact and foot tip contact with the ground must be made by adjusting the pitch angle of the leg relative to the ground. This method limits the leg's movement to the grounding mode, making it impossible to flexibly adjust the lower leg angle to maintain the robot's balance. Furthermore, components not in operation, due to their proximity to the grounding point, are prone to scraping or interfering with ground protrusions when walking on rough terrain. For schemes that directly use hub motors for brake locking and stepping with the outer edge of the tire, the geometry of the tire surface and... Frictional characteristics are not suitable as a fixed-point support surface. Slippage is likely to occur on wet or hard surfaces, and the impact load from running and jumping directly acts on the locked motor and reduction mechanism, which can easily cause internal mechanical damage. For the solution of increasing the degree of freedom by rotating the entire wheel set 90 degrees to use the side of the wheel as the foot, the mechanical complexity and rotational inertia of the foot end are significantly increased, which is not conducive to high-frequency dynamic control. Moreover, the side of the wheel hub is not designed for wear resistance and load-bearing, resulting in insufficient grip. As for the solution of using a linkage mechanism for storage and folding, under the high-frequency impact load of running and jumping, the increased clearance of the joint kinematic pairs due to fatigue wear will directly cause the structural sway of the support phase, reducing the support stability. In addition, the complex storage and folding mechanism is prone to jamming in muddy and sandy environments.

[0003] Most existing amphibious platforms have separate configurations for tires and propellers, which not only complicates the system structure and increases weight, but also introduces additional underwater drag. While some deformable wheel technologies can be reused as a propulsion device by unfolding blades, they cannot form a Mecanum wheel structure to achieve omnidirectional movement on land; moreover, such a single mechanism is difficult to simultaneously achieve the high flange stiffness required for land load-bearing and efficient underwater propulsion.

[0004] In buoyancy adjustment, air pumps combined with control frames featuring multiple solenoid valves are widely used. However, due to the numerous pipeline nodes, the intrusion of tiny particles increases the risk of valve core jamming or seal failure when used in sandy or high-salt-spray environments such as beaches. Furthermore, the inflation and deflation circuits often pass through different valve body channels, resulting in differences in flow resistance characteristics and asymmetrical speeds for bidirectional adjustment, posing a challenge to the robot's rapid posture balancing.

[0005] When performing dynamic docking operations on water surfaces, the impact of waves or currents can cause the robot to sway erratically. Traditional rigid guide rails or pin mechanisms require high initial alignment accuracy and are prone to self-locking during tilted contact. While magnetic connections offer some fault tolerance, their axial mechanical locking force is relatively limited when resisting strong winds and waves. Current technology lacks a self-guided docking device that can adapt to significant swaying and achieve rigid locking, thus limiting the robot's stable operation in continuous transitional scenarios involving land, shallow water, and underwater environments.

[0006] In summary, existing technologies have not yet simultaneously met the following requirements on the same platform and within the same mechanism: (1) It has a leg end structure with clear "roller ↔ point step" end position, reliable stroke and repeatable switching; (2) The same wheel can be folded up on land for rolling, and can be unfolded and horizontally rotated underwater to form a propulsion impeller; (3) Symmetrical, simplified and reliable buoyancy adjustment is achieved by directly connecting the airbag with a valveless, bidirectional air pump; (4) It has a fast docking mechanism that can self-guide and rigidly lock even under wind, waves, water flow and multi-posture swaying conditions; (5) It can maintain stable operation in continuous scenarios of land-shoal-water surface-underwater and adapt to multiple motion modes.

[0007] The market urgently needs a multi-amphibious and multi-form robot platform that can reliably operate in terms of structural compactness, clear switching, adaptability across land and water media, and multi-machine collaboration capabilities. Summary of the Invention

[0008] The purpose of this invention is to provide a multi-mode, multi-form amphibious robot that addresses the problems of unclear switching between wheeled and legged hybrid mechanisms and amphibious platform forms, high system redundancy, complex buoyancy control links, and insufficient docking fault tolerance in existing robots.

[0009] This invention integrates a head, head balance wheel assembly, wheel / point switching lower limb with a single-sided three-degree-of-freedom hip joint, expandable wheel assembly, buoyancy compensation unit, buoyancy adjustment unit, and quick-connect device within a single platform, achieving integrated operation of all actuators. On land, this invention uses an electric actuator to raise and lower the lower limb in conjunction with an embedded groove guide position to achieve controllable switching of the wheel / point switching lower limb between a two-wheel foot mode and a two-point foot mode. Furthermore, by combining different grounding states of system components, it constructs various land movement modes, including two-wheel foot mode, two-point foot mode, four-wheel mode, three-wheel mode, and self-balancing mode, to accommodate conditions such as long-distance rolling, high-mobility driving, and obstacle crossing. On the surface / underwater, this invention utilizes the unfolding of the wheel lobes and the rotation of the attitude switching motor of the deployable wheat wheel assembly to achieve the conversion of the deployable wheat wheel assembly from a vertical wheel posture on land to a horizontal propeller posture on the same wheel set for underwater propulsion. A basic drainage volume is provided through buoyancy compensation units on both sides, and symmetrical buoyancy adjustment is achieved through a buoyancy adjustment air path that connects the valveless bidirectional air pump directly to the airbag, thereby enabling continuous control of attitude and buoyancy within a range of shorelines, shallow water, and certain water depths. Simultaneously, the quick-connect device, through a combination of a conical self-guiding structure and electromagnetic locking, enables rapid docking and reliable unlocking between multiple units in turbulent environments such as wind, waves, or currents, supporting multi-unit collaboration and modular reconfiguration of tasks.

[0010] The objective of this invention is achieved through the following technical solution: a multi-mode, multi-form amphibious robot, which consists of a head, a head balance wheel assembly, a spreadable wheel assembly, a quick-connect device, a hip joint, and wheel / point switching lower limbs; The head balance wheel assembly is installed on the head and includes a bracket, a drive motor and a balance wheel connected to the motor. The balance wheel serves as a drive wheel assembly for driving in the robot's quadruped mode and as an independent drive wheel assembly in the balance vehicle mode. The deployable Mecanum wheel assembly includes a Mecanum wheel composed of multiple wheel segments, a wheel segment deployment / retraction mechanism, and an attitude switching motor. The wheel segments are distributed at equal angles along the circumference and have dual working modes: in the retracted state, each wheel segment closes to form a standard Mecanum wheel for omnidirectional travel on land and as a pivot point for wheel foot switching; in the deployed state, each wheel segment opens to form the impeller outline for underwater propulsion. The quick-connect device includes a tapered male connector driven by an electric actuator and an electromagnet for locking. The tapered male connector mates with a pre-reserved groove on the opposite side of the robot to achieve self-guided quick docking, and the electromagnet is used for locking after docking. The hip joint is located between the thigh and the body, and is a single-sided three-degree-of-freedom structure. It is formed by a series of roll, pitch, and yaw drive units to realize the three-degree-of-freedom movement of the lower limb in the roll, pitch, and yaw directions. The roll motor is fixed to the rear plate of the hip joint and together with the crossed roller bearing mounted on the front plate, it supports the yaw motor platform. The yaw motor is located at the center of the yaw motor platform, and its output end is connected to the pitch motor bracket. The pitch motor is mounted on the pitch motor bracket and is located at the root of the thigh and arranged opposite to the knee joint motor, thereby forming a controllable three-degree-of-freedom connection between the body and the thigh.

[0011] The wheel / point switching lower limb includes the foot, lower leg, knee joint, and thigh. The foot is composed of a point foot and a wheel foot assembly. The lower leg has an embedded groove, and a slider is guided and engaged within the groove. The electric actuator is installed on the front side of the lower leg, and its output end is connected to the slider to drive the wheel foot assembly to move along the groove direction, so that the wheel foot assembly enters the double wheel foot mode at the lower dead point and the double point foot mode at the upper dead point.

[0012] Furthermore, the tapered male connector has a taper angle of 60°, and its axis is consistent with the docking direction. The tapered male connector mates with the mating groove on another robot. A guide chamfer and mating gap are set at the entrance of the groove to achieve self-guided rapid docking. After docking, the locking unit composed of electromagnets keeps it locked. The electric push rod provides axial clamping force after contact. The locking unit completes the final lock. The unlocking sequence is to first release the electromagnetic lock and then retract the electric push rod.

[0013] Furthermore, the amphibious robot also includes a buoyancy compensation unit, which is composed of two pieces of PU polyurethane foam material and is located on both sides of the head. The volume is preset according to the target drainage volume. It is used to provide a constant drainage volume and cooperate with the buoyancy adjustment unit to achieve static buoyancy compensation. The buoyancy adjustment unit includes a bidirectional air pump, a small air cylinder and an external airbag arranged in the head. The buoyancy control of the whole machine is achieved by changing the gas volume in the airbag.

[0014] Furthermore, the embedded slide groove inside the lower limb of the wheel / point switching lower leg is a T-shaped groove. The slider moves along the groove axis parallel to the longitudinal direction of the lower leg. The wheel foot motor is fixed to the slider and connected to the wheel foot by bolts. Upper and lower stops are respectively set at both ends of the slide groove to limit the lifting stroke of the wheel foot assembly and achieve end positioning. Wear-resistant patches or surface hardening treatment can be provided on the side wall of the slide groove. Adaptive tolerances are used between the slider and the groove surface to reduce shaking. The stops can be equipped with flexible buffers or fine-tuning screws to absorb end impacts and correct end position differences. A hemispherical point foot is provided at the foot end, which serves as a ground contact element in the point foot mode when the wheel foot assembly is raised to the upper stop. The outer surface of the point foot can be coated with a wear-resistant coating and chamfered at the edges. The connection between the point foot and the lower leg adopts a replaceable structure to quickly change the contact material or diameter specification under different ground materials.

[0015] Furthermore, the foot is provided with a hemispherical foot piece, which is installed at the end of the lower leg and serves as a ground contact element in the foot-pointing mode when the wheel assembly rises to the upper stop point.

[0016] Furthermore, the deployable Mecanum wheel assembly adopts a four-lobed Mecanum wheel; each lobe has an independent first mounting hole and a second mounting hole. The first mounting hole is secured by a single fastening bolt that passes through the motor output disc, the lobe, and the servo mounting plate in sequence and is tightened. The second mounting hole is hinged to one side of the bracket, and the other side of the bracket is connected to the turntable. The servo drives the turntable to rotate, thereby driving the bracket to move and switching the lobe between retracting and unfolding. The output shaft of the attitude switching motor is connected to the fixed frame, and the fixed frame is hinged to the Mecanum wheel drive motor mounting plate. The attitude switching motor changes the position and attitude of the Mecanum wheel drive motor mounting plate by rotating the fixed frame to complete the switching between the vertical wheel form and the horizontal propeller form.

[0017] Furthermore, when the deployable Mecanum wheel assembly is not deployed, the rotation of the Mecanum wheel is controlled by a walking drive motor mounted on the slider, or it serves as a fulcrum to assist in switching between two-wheel foot and two-point foot modes.

[0018] Furthermore, the attitude switching motor is connected to the fixed frame via a flange, allowing the deployable wheel assembly to rotate around the axis of the attitude switching motor, thereby switching between vertical wheel posture and horizontal propeller posture.

[0019] Furthermore, after the Mecanum wheel is deployed, the four wheel petals are distributed at equal angles along the circumference. When deployed, they together form the outer profile of the impeller for underwater propulsion. The outer diameter after deployment is 1.4 times the outer diameter in the retracted state. The rotation angle range of the turntable driven by the servo motor is used to define the mechanical travel of the wheel petals from the retracted end to the deployed end.

[0020] Furthermore, the first bidirectional air pump of the two bidirectional air pumps operates in bidirectional mode and is connected to the external airbag. When rotating forward, it inflates the airbag, and when rotating backward, it draws air from the airbag and discharges it to the outside through its exhaust port. The two ends of the air pump are connected to the atmosphere and the airbag, respectively. The second air pump is also a bidirectional air pump, but operates in unidirectional mode. Its air inlet is connected to the normally open gas cylinder through a conduit, and its exhaust port is connected to the airbag through a sealed conduit. No valves are installed in the air circuit. The floating and sinking of the whole machine is controlled by changing the gas volume in the airbag. Pressure sensors can be arranged on the airbag as needed, and closed-loop regulation can be achieved in combination with the air pump current.

[0021] Furthermore, the amphibious robot has the following form: Three-wheel configuration: The lower limbs are in wheel-foot mode when the wheel / point switching is in the wheel-foot mode, the wheat-spreading wheel assembly is not deployed and is on the ground, and the head balance wheel assembly is suspended in the air; Four-wheel configuration: The wheel assembly is in wheel mode, the balance wheel of the head balance wheel assembly is on the ground, and the wheat spreading wheel assembly is suspended in the air; Dual-wheel configuration: The wheel assembly is in wheel mode, with only the left and right wheels touching the ground, while the head balance wheel assembly and the expandable wheat wheel assembly are suspended in the air; Dual-point foot configuration: The wheel and foot assembly rises to the top dead center and is in point-foot mode, with only the left and right points touching the ground, while the head balance wheel assembly and the expandable wheat wheel assembly are suspended in the air; Surface and underwater configuration: The deployable wheat wheel assembly is in the deployed propeller position, working as an underwater propulsion device, and works with the buoyancy compensation and buoyancy adjustment unit to achieve underwater or surface movement; Self-balancing scooter configuration: The head balance wheel assembly serves as the only wheel group touching the ground and provides the main support. The body is arranged vertically and achieves self-balancing through attitude control.

[0022] The beneficial effects of the multi-mode, multi-form amphibious robot proposed in this invention are as follows: 1. This invention integrates a head balance wheel assembly, an independent three-degree-of-freedom hip joint, and a wheel / point switching lower limb within a single platform. Through linear lifting with an electric push rod, an embedded T-shaped slide, and upper / lower stops, it achieves a clear end position and high repeatability of morphological switching between wheel feet and point feet.

[0023] 2. The present invention adopts an expandable Mecanum wheel assembly, which can be used as a Mecanum wheel to achieve omnidirectional walking on land when folded, and can be used as an underwater propulsion impeller after being unfolded and rotated to a horizontal position by an attitude switching motor, thus realizing the efficient reuse of the same actuator in both land walking and underwater propulsion conditions.

[0024] 3. This invention constructs various working modes such as dual-wheel foot, dual-point foot, three-wheel, four-wheel, balance vehicle, and water surface / underwater by using different grounding combinations of the head balance wheel assembly, wheel / point switching lower limbs, and unfoldable wheat wheel assembly, which significantly improves the platform's adaptability to working conditions and posture diversity.

[0025] 4. The present invention adopts a structure of "PU polyurethane foam material + valveless bidirectional air pump + external airbag" in the buoyancy control part. By changing the volume of the airbag, symmetrical floating and sinking and closed-loop regulation are achieved. Compared with multi-valve air circuits, the sealing points and failure points are significantly reduced, and the reliability of long-term underwater operation is improved.

[0026] 5. The quick connection device of the present invention adopts a conical male connector driven by an electric push rod and an electromagnetic locking structure, which has both guiding self-centering and rigid locking capabilities, and can realize rapid docking and reliable unlocking between multiple platforms under the presence of attitude disturbances and environmental disturbances. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the entire machine of the present invention (with dual wheel feet). Figure 2 This is a supplementary view of the entire machine of the present invention (dual-wheel foot configuration). Figure 3 This is a schematic diagram of the dual-point foot morphology and its variations as described in this invention; Figure 4 This is a schematic diagram of the three-wheel configuration described in this invention; Figure 5 This is a schematic diagram of the four-wheel configuration described in this invention; Figure 6 This is a schematic diagram illustrating the use of a self-balancing scooter to grip an item, as described in this invention. Figure 7 This is a schematic diagram of the robot's rapid propulsion mode on the water surface as described in this invention; Figure 8 This is a schematic diagram of the robot's water-walking mode according to the present invention; Figure 9 This is a schematic diagram of the robot's rapid underwater diving mode as described in this invention; Figure 10 This is a schematic diagram of the docking of the two robots described in this invention; Figure 11 This is a schematic diagram of the unfoldable wheat wheel assembly. Figure 12 Supplementary view for unfolded expandable McLaren assembly; Figure 13 This is a schematic diagram of the internal structure of the lower limbs, showing the wheel / point switching mechanism. Figure 14 Axonometric view of the lower limbs with wheel / point switching; Figure 15 Axonometric drawing of the quick-connect device; Figure 16 Axonometric view of a three-degree-of-freedom hip joint; Figure 17 This is a schematic diagram showing the arrangement of the buoyancy compensation unit and the buoyancy adjustment unit; Figure label: 1. Buoyancy compensation unit; 2. Expandable wheat wheel assembly; 2-1. Wheat wheel rim; 2-2. First mounting hole; 2-3. Second mounting hole; 2-4. Bracket; 2-5. Turntable; 2-6. Servo mounting plate; 2-7. Servo; 2-8. Fixture; 2-9. Motor mounting plate; 2-10. Motor output plate; 2-11. Output end gasket; 2-12. Travel drive motor; 3. Wheel / point switching lower limb; 3-1. Point foot; 3-2. Slide groove; 3-3. Electric actuator slider connector; 3-4. Slider; 3-5. Wheel set motor; 3-6. Electric actuator; 3-7. Reserved slot; 3-8. Dustproof shell; 3-9. Wheel foot; 4. Head balance wheel assembly; 5. Quick connection device; 5-1 5-1. Electric actuator; 5-2. Actuator mounting bracket connector; 5-3. Electromagnet wiring trough; 5-4. Electromagnet mounting bracket; 5-5. Connecting bolt; 5-6. Electromagnet; 6. Three-degree-of-freedom hip joint; 6-1. Crossed roller bearing; 6-2. Rear mounting plate of lower limb connection module; 6-3. Fixed-length sleeve and plug bolt connection device; 6-4. Hip joint yaw motor; 6-6. Yaw motor platform; 6-6. Hip joint roll motor; 6-7. Pitch motor mounting bracket; 6-8. Hip joint pitch motor; 7. Buoyancy adjustment unit; 7-1. Telescopic airbag; 7-2. Small air cylinder; 7-3. Air cylinder inlet pipe; 7-4. Bidirectional air pump; 8. Materials; 9. Coffee table; 10. Fan blade. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are merely illustrative and not intended to limit the invention.

[0030] like Figure 1 and Figure 2 As shown in this embodiment, the multi-mode, multi-form amphibious robot provided by the present invention includes modules such as a buoyancy compensation unit 1, a deployable wheel assembly 2, a wheel / point switching lower limb 3, a head balance wheel assembly 4, a quick connection device 5, a three-degree-of-freedom hip joint 6, and a buoyancy adjustment unit 7. Figure 1 , Figure 2 The overall structure of the robot in wheeled leg configuration is given. Figures 3 to 10 The diagrams sequentially illustrate typical working modes such as wheeled, point-footed, three-wheeled, four-wheeled, self-balancing scooter, surface / underwater, and docking of two vehicles.

[0031] On the same platform, the electric actuator 3-6 on the wheel / point switching lower limb 3 drives the slider 3-4 to rise and fall along the inner groove 3-2 of the lower leg, allowing the wheel foot 3-9 to switch between the lower dead point and the upper dead point, thus achieving a clear end position and continuous process transition between the two forms of wheel foot and point foot; when the deployable wheel assembly 2 is in the retracted form on land, the walking drive motor 2-12 realizes rolling and lateral movement, and acts as a fulcrum during the wheel foot switching process; before entering deep water, the servo motor 2-7 drives the turntable 2-5 to unfold the wheel petals 2-1, and after unfolding, the attitude switching motor drives the fixed frame 2-8 to rotate, allowing the deployable wheel assembly 2 to switch between vertical wheel posture and horizontal propeller posture, which is used to provide underwater propulsion in different directions. The buoyancy compensation unit 1 provides a constant displacement volume, and the buoyancy adjustment unit 7 achieves buoyancy control through the volume change of the telescopic airbag 7-1; the quick connection device 5 relies on the cone surface self-guidance and electromagnetic locking to achieve quick docking and disengagement between multiple platforms.

[0032] The head balance wheel assembly 4 is mounted on the head and includes two end brackets and drive motors and balance wheels respectively mounted on the brackets. The bottom of the brackets has mounting holes, and the head balance wheel assembly 4 connects to the head through these holes. In the robot's quadruped mode, the balance wheels participate in support and movement; in the balance vehicle mode, they provide support and drive as an independent wheel assembly. Figure 17 As shown, the buoyancy compensation unit 1 uses PU polyurethane foam blocks as its main structure. The entire unit is fixed to the inner surface of the outer shell on both sides of the robot's head by means of adhesion and bolts. Its volume is pre-designed according to the target drainage volume of the whole machine. During operation, the buoyancy compensation unit 1 does not participate in dynamic adjustment, but only provides a constant drainage volume to offset part of its own weight and achieve basic buoyancy compensation.

[0033] When the robot performs tasks on the surface or underwater, the buoyancy compensation unit 1 and the buoyancy adjustment unit 7 work together: the buoyancy compensation unit 1 provides a stable reference buoyancy, while the buoyancy adjustment unit 7 corrects the buoyancy by adjusting the airbag volume. This enables the robot to ascend and descend.

[0034] like Figure 11 and Figure 12 As shown, the deployable wheel assembly 2 of the multi-purpose robot consists of wheel lobes 2-1, first mounting hole 2-2, second mounting hole 2-3, bracket 2-4, turntable 2-5, servo motor mounting plate 2-6, servo motor 2-7, fixed frame 2-8, motor mounting plate 2-9, motor output plate 2-10, output end gasket 2-11, and walking drive motor 2-12.

[0035] The mounting bracket 2-8 and the motor mounting plate 2-9 are reliably connected by hexagon socket head cap screws, forming a rigid, integrated mounting base. The travel drive motor 2-12 is fixed to the motor mounting plate 2-9 by bolts. The motor output disc 2-10 and the output end washer 2-11 are sequentially mounted on its rotor end and tightened by multiple fastening bolts to ensure reliable transmission of motor torque. A long bolt passes sequentially through the first mounting hole 2-2 on the motor output disc 2-10, the wheel lobe 2-1, and the servo mounting plate 2-6, and is tightened at the end, thereby ensuring coaxial positioning and rigid connection between the motor output disc 2-10, the servo mounting plate 2-6, and each wheel lobe 2-1.

[0036] The second mounting hole 2-3 is hinged to one side of the bracket 2-4, and the other side of the bracket 2-4 is hinged to the turntable 2-5, forming a motion chain of "servo mounting plate - turntable - bracket - wheel lobe". The servo 2-7 is fixed to the servo mounting plate 2-6, and its output shaft is fixedly connected to the turntable 2-5. When the servo 2-7 rotates, it drives the turntable 2-5 to rotate, which in turn changes the opening and closing angle of the wheel lobe 2-1 through the bracket 2-4, realizing the switching between the retracted position and the extended position of the wheel lobe.

[0037] The fixed frame 2-8 is connected to the output end of the attitude switching motor via a flange. The attitude switching motor drives the fixed frame 2-8 and the entire deployable Mecanum wheel assembly 2 on it to rotate around the motor axis, thereby switching between two typical attitudes: one is a vertical wheel attitude with the wheel surface approximately vertical, used for land rolling; the other is a horizontal propeller attitude with the wheel surface approximately horizontal, used for underwater propulsion. The four wheel petals 2-1 are distributed at equal angles along the circumference, forming the Mecanum wheel profile in the folded form, which can be driven by the travel drive motor 2-12 to achieve forward, backward, and lateral movement; in the unfolded form, the four wheel petals 2-1 together form an impeller profile with an increased outer diameter, effectively pushing the water body to generate propulsion force or attitude adjustment torque, thereby realizing the integrated reuse of the land wheel assembly and the underwater propulsion impeller.

[0038] like Figure 13 and Figure 14 As shown, the wheel / point switching lower limb 3 of the multi-purpose robot is composed of parts such as point foot 3-1, slide 3-2, electric push rod slider connector 3-3, slider 3-4, wheel set motor 3-5, electric push rod 3-6, reserved slot 3-7, dustproof shell 3-8, and wheel foot 3-9.

[0039] The foot 3-1 is coaxially mounted at the foot end, coinciding with the lower leg axis, for contact with the ground in point-foot mode. A longitudinal groove 3-2 is formed inside the lower leg, within which the slider 3-4 performs linear guided motion. The groove 3-2 employs an embedded T-slot structure to improve the slider's guiding rigidity and limit its lateral sway. An electric actuator 3-6 is located on the front side of the lower leg, its output end rigidly connected to the slider 3-4 via an electric actuator-slider connector 3-3. When the electric actuator extends or retracts, it drives the slider 3-4 to rise and fall along the groove 3-2. The wheel motor 3-5 is bolted to the slider 3-4 and coaxially connected to the wheel foot 3-9, forming a wheel foot drive unit that rises and falls with the entire slider.

[0040] A pre-reserved slot 3-7 is provided on the outer side of the slide block 3-4 to ensure that the slider 3-4 and its fastening bolt heads can pass smoothly to the lower stop point without interfering with the housing. The dust cover 3-8 covers the entire slide groove area to prevent foreign objects such as mud and water droplets from entering the slide groove 3-2 and affecting the guiding performance. By setting mechanical stops at both ends of the slide groove 3-2, the upper and lower limit positions of the slider 3-4 can be limited respectively.

[0041] like Figure 3 As shown, the motion process of the lower limb 3 switching between wheel and point is as follows: when the slider 3-4 is at the lower stop point, the wheel foot 3-9 touches the ground to form the wheel foot mode. Figure 3 The left side of the state corresponds to the whole. Figure 1 , Figure 2 As the electric actuator 3-6 extends, the slider 3-4 moves upward along the groove 3-2, the wheel foot 3-9 gradually lifts off the ground, and the point foot 3-1 gradually approaches the ground, entering the intermediate transition state. Figure 3 (The intermediate state); when it continues to extend to the upper stop point, wheel feet 3-9 are completely lifted off the ground, and only point foot 3-1 touches the ground to form a point foot pattern ( Figure 3 (Right side state). The above three stages constitute a continuous wheel-foot to point-foot switching action, making the contact form conversion process controllable and repeatable, and facilitating stable use in various terrains.

[0042] like Figure 15 As shown, the quick connection device 5 of the multi-purpose robot consists of parts such as an electric push rod 5-1, a push rod electromagnet mounting base connector 5-2, an electromagnet wiring groove 5-3, an electromagnet mounting base 5-4, a connecting bolt 5-5, and an electromagnet 5-6.

[0043] The actuator 5-1 has a mounting hole at its head. A connecting bolt passes through this mounting hole and is secured to the mounting base connector 5-2, ensuring a reliable connection between the actuator 5-1 and the subsequent structure. The mounting base connector 5-2 is then fixed to the electromagnet mounting base 5-4 by connecting bolts 5-5, preferably using anti-slip nuts with self-locking function to prevent loosening under vibration conditions. The electromagnet 5-6 is fixedly installed inside the electromagnet mounting base. Its power and signal lines are arranged along the electromagnet wiring groove 5-3 and connected to the main body wiring harness for easy wiring and maintenance.

[0044] In use, a tapered male connector is provided on one side of the main body, with a tapered angle of 60° and its axis aligned with the docking direction; a groove is provided on the docking side to mate with it, and a guide chamfer is provided at the entrance of the groove with an appropriate mating gap. When the robot performs docking operations, under certain posture and positional errors, the tapered male connector automatically centers itself and slides into the mating position under the guidance of the chamfer at the entrance of the groove, achieving self-guiding positioning; after the electric push rod 5-1 extends and is pushed into place, the electromagnet 5-6 is energized and attracted, forming a closed magnetic circuit with the metal part on the opposite side.

[0045] like Figure 10 As shown, after the two robots dock via the quick-connect device 5, they can form an integrated platform for collaborative transport, traversing larger obstacles, or carrying large payloads. To unlock, the electromagnet 5-6 is first de-energized to release it, and then the electric push rod 5-1 is retracted, allowing for rapid disengagement. This meets the needs of frequent docking / separation switching for multi-robot collaboration and modular task reconfiguration.

[0046] like Figure 16 As shown, the three-degree-of-freedom hip joint 6 consists of a rear mounting plate 6-2 of the lower limb connection module, a cross roller bearing 6-1, a fixed-length sleeve and plug bolt connection device 6-3, a hip joint yaw motor 6-4, a yaw motor platform 6-6, a hip joint roll motor 6-6, a pitch motor mounting base 6-7, and a hip joint pitch motor 6-8.

[0047] The roll motor 6-6 is fixedly mounted on the rear side of the mounting plate 6-2, forming a roll drive unit between the hip joint and the machine body. A cross roller bearing 6-1 is coaxially arranged on the opposite side of the mounting plate 6-2 to jointly support the yaw motor platform 6-6 and ensure high rigidity and positioning accuracy of the yaw degree of freedom under large loads. The hip joint yaw motor 6-4 is mounted in the middle of the yaw motor platform 6-6 and is fastened to the platform via a fixed-length sleeve and plug bolt connection device 6-3 to ensure that the yaw output shaft is coaxial with the axis of the cross roller bearing 6-1.

[0048] The pitch motor mounting base 6-7 is located at the root of the thigh, and the hip joint pitch motor 6-8 is fixed to the mounting base 6-7 and connected to the thigh, thus forming a three-degree-of-freedom series structure of "roll-yaw-pitch" between the body and the thigh. This structure provides a wide range of posture adjustment capabilities for the wheel / point switching lower limb 3, and plays a key role in the balance bike mode and the inverted gripping mode: such as... Figure 6 As shown, the hip joint coordinates three degrees of freedom of movement, allowing the body to smoothly transition from a normal posture to an upright or inverted posture, while the lower limbs take on the functions of grasping and supporting.

[0049] like Figure 17 As shown, the buoyancy adjustment unit 7 of the multi-purpose robot consists of a telescopic airbag 7-1, a small air cylinder 7-2, an air cylinder inlet pipe 7-3, and a bidirectional air pump 7-4.

[0050] This embodiment uses two bidirectional air pumps 7-4: The first bidirectional air pump operates in bidirectional mode, with its inlet connected to the atmosphere and its outlet connected to the telescopic airbag 7-1; when rotating forward, it inflates the telescopic airbag 7-1, and when rotating backward, it draws air from the telescopic airbag 7-1 and discharges it to the outside through its outlet, thus achieving gas exchange with the atmosphere. The second bidirectional air pump is configured in unidirectional mode, with its inlet connected to a normally open small air cylinder 7-2 installed inside the head as a high-pressure air source via an air cylinder inlet pipe 7-3, and its outlet connected to the telescopic airbag 7-1 via a sealed conduit. No mechanical valves are installed in the entire air circuit; the inflation and deflation path is entirely determined by the operating directions of the two bidirectional air pumps. This simple structure and fewer sealing points contribute to improved reliability for long-term underwater operation.

[0051] By controlling the start, stop, and directional control of the two air pumps 7-4, the gas volume inside the telescopic airbag 7-1 can be changed according to different water depths and attitude requirements, thereby adjusting the robot's overall buoyancy and center of buoyancy position. A pressure sensor can be installed on the telescopic airbag 7-1 to monitor the internal pressure in real time. The control system integrates the pressure signal and the air pump current signal to achieve closed-loop regulation, enabling the robot to obtain a stable and predictable buoyancy response during ascent, descent, and underwater hovering.

[0052] like Figures 1-9 As shown, various land-based and surface / underwater working modes are illustrated. The amphibious robot of this invention can form a series of working modes with distinct functional characteristics through different grounding combinations of wheeled legs 3-9, point legs 3-1, deployable wheel assembly 2, and head balancing wheel assembly 4. Continuous transitions between modes can be achieved through the coordinated movements of the wheel / point switching lower limbs 3, the three-degree-of-freedom hip joint 6, and the deployable wheel assembly 2. Specifically, it includes: (1) Basic form of double-wheel foot (wheel foot located at the bottom dead center) (corresponding to) Figure 1 , Figure 2 ) exist Figure 1and Figure 2 In the basic configuration shown, both of the robot's wheel / point switching limbs 3 are in wheel-foot mode, with wheel feet 3-9 on the ground. The head balancing wheel assembly 4 and the unfolding wheel assembly 2 are both lifted off the ground. This configuration is the basic driving mode of the robot on land, enabling efficient rolling on ordinary roads while retaining a certain ability to cross obstacles. It serves as the starting or intermediate posture when switching to other configurations.

[0053] (2) Two-point foot configuration (wheel foot located at the top dead center) (corresponding to) Figure 3 ) like Figure 3 As shown, the entire process of switching from wheel-foot mode to point-foot mode is illustrated from left to right. Initially, slider 3-4 is at the lower stop of groove 3-2, wheel motor 3-5 and wheel 3-9 are at their lowest positions and rolling in contact with the ground, while point-foot 3-1 is suspended. At this time, the robot moves using wheel 3-9 as the main load-bearing unit. During the switch, electric actuator 3-6 slowly retracts along a predetermined stroke, driving the electric actuator slider connector 3-3 and slider 3-4 upwards along groove 3-2. Wheel 3-9 is then lifted longitudinally along the lower leg, and the normal reaction force at the contact point between the wheel and the ground gradually decreases. Simultaneously, point-foot 3-1 gradually approaches the ground, achieving a smooth transition of support force between the wheel and point-foot modes. When slider 3-4 rises to the upper stop position, wheel 3-9 is completely lifted off the ground, with only point-foot 3-1 making point contact with the ground. The head balance wheel assembly 4 and the expandable wheel assembly 2 remain suspended. At this point, the robot enters point-foot mode. Because the chute 3-2 provides strict linear guidance to the slider 3-4, and the upper and lower stops mechanically limit the end position, and with the position feedback of the stroke sensor or electric push rod, the stroke consistency and end position repeatability of each wheel foot / point foot switching can be guaranteed, avoiding lateral swaying and interference. Thus, in complex terrains such as high embankments, gravel, and soft foundations, the transition from wheel foot rolling mode to foot-based obstacle crossing walking mode can be reliably realized.

[0054] (3) Three-wheel configuration (two-wheeled legs + undeployed Mecanum wheel) (corresponding to) Figure 4 ) like Figure 4 As shown, when the lower limbs 3 on both sides maintain the wheel-foot mode and are on the ground, the spreadable wheel assembly 2 is in the folded state with its Mecanum wheel in contact with the ground, and the head balance wheel assembly 4 is in a suspended state, the three grounding points together form a stable support triangle. This three-wheel configuration is suitable for low-speed parking, fine-tuning of posture, and as a fulcrum configuration for wheel-foot switching, and can significantly improve static stability without adding an additional support mechanism.

[0055] (4) Four-wheel configuration (two wheels + head balance wheel) (corresponding to) Figure 5 ) like Figure 5As shown, wheel feet 3-9 are in wheel foot mode and on the ground, and the two balance wheels of the head balance wheel assembly 4 are simultaneously in contact with the ground. When the expandable wheel assembly 2 is raised and suspended in the air, the robot forms a four-wheel configuration with the front balance wheel assembly 4 and the two wheel feet 3-9 on the middle sides. This four-wheel configuration provides good straight-line stability and steering maneuverability on hard, flat surfaces, making it suitable for long-distance cruising, rapid maneuvering, and other tasks. It is one of the main working modes for efficient land travel.

[0056] (5) Balance bike form (independent drive of balance wheels) and inverted gripping mode (corresponding to) Figure 6 ) like Figure 6 As shown, with the rotation and pitch degrees of freedom of the hip joint 6, the robot body can be adjusted to a near-vertical or even partially inverted posture, with only the pair of balance wheels of the head balance wheel assembly 4 grounded for support, while the wheel feet 3-9 and the unfoldable wheel assembly 2 are all lifted off the ground. At this time, the robot uses the head balance wheel assembly 4 as the main support point and achieves self-balancing rolling through posture control, similar to the dynamic movement of a balance scooter.

[0057] In this configuration, the two wheel / point switching lower limbs 3 flip up to the top of the machine body and are used as a robotic arm-like operating mechanism to perform operations such as gripping, carrying or supporting the materials 8 placed on the coffee table 9, thereby realizing the functional conversion of "walking mechanism - operating mechanism" and fully demonstrating the robotic arm application of the lower limb structure in the inverted working condition.

[0058] (6) Surface / underwater morphology (corresponding to) Figure 7 , Figure 8 , Figure 9 ) like Figure 7 As shown, before the robot enters the water, the servo motor 2-7 unfolds the wheel segments 2-1 from the retracted position, and then the attitude switching motor drives the fixed frame 2-8 to rotate the deployable wheel assembly 2 to a horizontal propeller attitude. At this time, the impeller outline formed by the four wheel segments 2-1 works as an underwater propulsion impeller, pushing the water under the drive of the walking drive motor 2-12.

[0059] In conjunction with the constant drainage volume provided by the buoyancy compensation unit 1 and the fine adjustment of the volume of the telescopic airbag 7-1 by the buoyancy adjustment unit 7, such as Figure 9 As shown, the robot can switch its lower limb postures using three wheel points to achieve various underwater movement modes, such as rapid propulsion, paddling, and rapid diving. Specifically, when buoyancy exceeds gravity, the inflatable airbags fully deploy, enabling... Figure 7 The rapid advancement mode or implementation shown is as follows Figure 9 The paddling pattern shown; when buoyancy is less than gravity, it achieves the following: Figure 8 The rapid descent mode shown.

[0060] (7) Two-engine docking and cooperative configuration (corresponding to) Figure 10 ) like Figure 10 As shown, when the task requires expanding the support area, increasing the load capacity, or achieving collaborative operation, the two robots can dock through the quick connection device 5. Utilizing the self-guiding characteristics of the tapered male connector and the rigid locking function of the electromagnets 5-6, the two robots can still achieve reliable self-guiding docking and locking even with certain attitude and position errors.

[0061] After docking, the two robots form an integrated frame-like combined platform, which can perform tasks such as obstacle crossing, traction, large platform loading, or collaborative transportation in a dual-robot formation according to task requirements. Compared with the single-robot mode, this significantly improves the system's task scale and environmental adaptability.

[0062] Through the multidimensional combination of the above-mentioned various configurations and their transformation relationships, this invention achieves continuous coverage of multiple modes, from legged obstacle crossing and wheeled cruising to underwater propulsion, self-balancing rolling and multi-machine collaboration, without adding additional actuators, significantly improving the robot's mobility and task expansion capabilities in multi-media and multi-working-condition environments.

[0063] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A multi-mode, multi-form amphibious robot, characterized in that, This amphibious robot consists of a head, a head-balancing wheel assembly, a spreadable wheel assembly, a quick-connect device, a hip joint, and wheel / point switching lower limbs. The head balance wheel assembly is installed on the head and includes a bracket, a drive motor and a balance wheel connected to the motor. The balance wheel serves as a drive wheel assembly for driving in the robot's quadruped mode and as an independent drive wheel assembly in the balance vehicle mode. The deployable Mecanum wheel assembly includes a Mecanum wheel composed of multiple wheel segments, a wheel segment deployment / retraction mechanism, and an attitude switching motor. The wheel segments are distributed at equal angles along the circumference and have dual working modes: in the retracted state, each wheel segment closes to form a standard Mecanum wheel for omnidirectional travel on land and as a pivot point for wheel foot switching; in the deployed state, each wheel segment opens to form the impeller outline for underwater propulsion. The quick-connect device includes a tapered male connector driven by an electric actuator and an electromagnet for locking. The tapered male connector mates with a pre-reserved groove on the opposite side of the robot to achieve self-guided quick docking, and the electromagnet is used for locking after docking. The hip joint is a single-sided three-degree-of-freedom structure, formed by a series of roll, pitch, and yaw drive units; the roll motor is fixed to the rear plate of the hip joint, and together with the cross roller bearing installed on the front plate, it supports the yaw motor platform. The yaw motor is located at the center of the yaw motor platform, and its output end is connected to the pitch motor bracket; the pitch motor is installed on the pitch motor bracket. The wheel / point switching lower limb includes the foot, lower leg, knee joint, and thigh. The foot is composed of a point foot and a wheel foot assembly. The lower leg has an embedded groove, and a slider is guided and engaged within the groove. The electric actuator is installed on the front side of the lower leg, and its output end is connected to the slider to drive the wheel foot assembly to move along the groove direction, so that the wheel foot assembly enters the double wheel foot mode at the lower dead point and the double point foot mode at the upper dead point.

2. The multi-mode, multi-form amphibious robot according to claim 1, characterized in that, The amphibious robot also includes a buoyancy compensation unit, which consists of two pieces of PU polyurethane foam material, located on both sides of the head. The volume is preset according to the target drainage volume, and it is used to provide a constant drainage volume and cooperate with the buoyancy adjustment unit to achieve static buoyancy compensation. The buoyancy adjustment unit includes a bidirectional air pump, a small air cylinder and an external airbag arranged in the head, and the buoyancy control of the whole machine is achieved by changing the gas volume in the airbag.

3. The multi-mode, multi-form amphibious robot according to claim 1, characterized in that, The embedded slide groove inside the lower leg of the wheel / point switching mechanism is a T-shaped groove. The slider moves along the groove axis parallel to the longitudinal direction of the lower leg. The upper stop and lower stop are respectively set at both ends of the slide groove to limit the lifting stroke of the wheel assembly and achieve positioning at both ends.

4. The multi-mode, multi-form amphibious robot according to claim 1, characterized in that, The foot is provided with a hemispherical foot piece, which is installed at the end of the lower leg and serves as a ground contact element in the foot-pointing mode when the wheel assembly rises to the upper stop point.

5. A multi-mode, multi-form amphibious robot according to claim 1, characterized in that, The deployable Mecanum wheel assembly adopts a four-lobed Mecanum wheel; each lobe has an independent first mounting hole and a second mounting hole. The first mounting hole is secured by a single fastening bolt that passes through the motor output disc, the lobe, and the servo mounting plate in sequence and is tightened. The second mounting hole is hinged to one side of the bracket, and the other side of the bracket is connected to the turntable. The servo drives the turntable to rotate, thereby driving the bracket to move and switching the lobe between retracting and unfolding. The output shaft of the attitude switching motor is connected to the fixed frame, and the fixed frame is hinged to the Mecanum wheel drive motor mounting plate. The attitude switching motor changes the position and attitude of the Mecanum wheel drive motor mounting plate by rotating the fixed frame to complete the switching between the vertical wheel form and the horizontal propeller form.

6. The multi-mode, multi-form amphibious robot according to claim 1, characterized in that, When the deployable Mecanum wheel assembly is not deployed, the rotation of the Mecanum wheel is controlled by a walking drive motor mounted on the slider, or it can be used as a fulcrum to switch between two-wheel foot and two-point foot modes.

7. A multi-mode, multi-form amphibious robot according to claim 1, characterized in that, The attitude switching motor is connected to the fixed frame via a flange, allowing the deployable wheel assembly to rotate around the axis of the attitude switching motor, thereby switching between vertical wheel posture and horizontal propeller posture.

8. A multi-mode, multi-form amphibious robot according to claim 5, characterized in that, The outer diameter of the Mecanum wheel when it is extended is 1.4 times that when it is retracted. The rotation angle range of the turntable driven by the servo motor is used to define the mechanical travel of the wheel petals from the retracted end to the extended end.

9. A multi-mode, multi-form amphibious robot according to claim 2, characterized in that, The first bidirectional air pump of the two bidirectional air pumps operates in bidirectional mode and is connected to the external airbag for inflating and deflating the external airbag; the second bidirectional air pump operates in unidirectional mode, with its air inlet connected to the normally open gas cylinder via a conduit and its exhaust port connected to the airbag via a sealed conduit; no valves are installed in the air circuit, and the floating and sinking of the whole machine is controlled by changing the gas volume inside the airbag.

10. A multi-mode, multi-form amphibious robot according to claim 1, characterized in that, The amphibious robot has the following form: Three-wheel configuration: The lower limbs are in wheel-foot mode when the wheel / point switching is in the wheel-foot mode, the wheat-spreading wheel assembly is not deployed and is on the ground, and the head balance wheel assembly is suspended in the air; Four-wheel configuration: The wheel assembly is in wheel mode, the balance wheel of the head balance wheel assembly is on the ground, and the wheat spreading wheel assembly is suspended in the air; Dual-wheel configuration: The wheel assembly is in wheel mode, with only the left and right wheels touching the ground, while the head balance wheel assembly and the expandable wheat wheel assembly are suspended in the air; Dual-point foot configuration: The wheel and foot assembly rises to the top dead center and is in point-foot mode, with only the left and right points touching the ground, while the head balance wheel assembly and the expandable wheat wheel assembly are suspended in the air; Surface and underwater configuration: The deployable wheat wheel assembly is in the deployed propeller position and functions as an underwater propulsion device; Self-balancing scooter configuration: The head balance wheel assembly serves as the only wheel group in contact with the ground and provides the main support, achieving self-balancing through attitude control.

Images