Leg folding, extending, and retracting deformation mechanism of a quadruped wheel-leg composite robot

Abstract

The leg folding, extension, and telescopic deformation mechanism of a four-legged, wheel-legged composite robot belongs to a wheel-legged robot. Existing four-legged, wheel-legged composite robots cannot realize the independent contraction movement of a single leg, and have poor obstacle avoidance and movement capabilities. The upper rotating wheel is stacked on the lower rotating wheel, and the upper rotating wheel and the lower rotating wheel are provided with notches of the same shape at the same position, and the notches are evenly provided along the edges of the upper rotating wheel and the lower rotating wheel; a horizontal and vertical slide rail assembly is provided on the bottom surface of the lower rotating wheel near each notch, and one end of each traction mechanism moves in the vertical direction between the notch of the upper rotating wheel and the notch of the lower rotating wheel through the corresponding horizontal and vertical slide rail assembly. The movement of one end of the traction mechanism drives the head end transmission member of the wheel leg connected to its other end to move in the horizontal direction of the corresponding horizontal and vertical slide rail assembly, thereby realizing the extension and retraction of the wheel leg. The present invention is used to realize the extension and retraction of a single leg.

Description

Technical Field

[0001] The invention relates to a folding, expanding, telescopic and deformation mechanism, and belongs to a wheel-legged robot. Background Art

[0002] The advantages of a quadruped wheel-leg hybrid robot are significant. It is a mobile robot that combines both a wheeled structure and a legged structure. The wheel-leg hybrid structure installs wheels on the foot ends of the legged robot, replacing feet with wheels. This design, which combines the rapid movement capabilities of a wheeled robot with the flexible obstacle-crossing capabilities of a legged robot, greatly improves the robot's maneuverability and can be widely used in scenarios such as terrain exploration, disaster relief, military defense, and household services, effectively broadening the robot's application range. The folding and unfolding mechanism is a mechanism that can be controllably unfolded from a folded state to a desired or predetermined structural form and can withstand the corresponding load. In robots that need to adapt to different pipe diameters and complex environments, the folding and unfolding mechanism can realize the extension, folding, and angle adjustment of the tracks, improving the robot's diameter adjustment capability and flexibility.

[0003] An existing locomotion mechanism for a quadrupedal wheel-legged robot uses a double-layered eccentric wheel to simultaneously flex, extend, and contract the robot's four legs. While this mechanism enables smooth and efficient movement of the wheel-legged quadruped robot, it suffers from certain drawbacks: it can only achieve synchronous contraction of all legs, not independent contraction of a single leg. This results in poor obstacle avoidance and mobility when the wheel-legged robot is performing tasks across complex terrain. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing four-legged wheel-legged compound robot cannot realize the independent contraction movement of a single leg, resulting in poor obstacle avoidance and movement capabilities, and proposes a leg folding, extension, and telescopic deformation mechanism for the four-legged wheel-legged compound robot.

[0005] The legs of the quadruped wheel-leg composite robot are folded, extended, and retracted. The deformation mechanism includes an upper rotating wheel, a lower rotating wheel, two drive mechanisms, four traction mechanisms, four horizontal and vertical slide rail assemblies, and four self-locking mechanisms.

[0006] Two driving mechanisms are used to drive the upper rotating wheel and the lower rotating wheel to rotate respectively;

[0007] The upper rotating wheel is stacked above the lower rotating wheel, and notches of the same shape are provided at the same position of the upper rotating wheel and the lower rotating wheel, and the notches are evenly provided along the edges of the upper rotating wheel and the lower rotating wheel; a horizontal and vertical slide rail assembly is provided on the bottom surface of the lower rotating wheel near each notch, and one end of each traction mechanism moves in the vertical direction between the notch of the upper rotating wheel and the notch of the lower rotating wheel through the corresponding horizontal and vertical slide rail assembly, and the movement of one end of the traction mechanism drives the head end transmission member of the caster leg connected to the other end thereof to move in the horizontal direction of the corresponding horizontal and vertical slide rail assembly, thereby realizing the extension and retraction of the corresponding caster leg;

[0008] Each self-locking mechanism is used to lock or unlock one end of the traction mechanism that moves to the notch of the upper rotating wheel.

[0009] Preferably, each horizontal and vertical slide rail assembly comprises a vertical guide rail and a horizontal guide rail;

[0010] One end of the horizontal guide rail is horizontally fixed to the bottom of the lower rotating wheel, and the other end of the horizontal guide rail is a free end;

[0011] The vertical guide rail is fixedly connected to the upper surface of one end of the horizontal guide rail, and the vertical guide rail is embedded in the notch of the lower rotating wheel;

[0012] One end of each traction mechanism is arranged on a vertical guide rail, and the other end of each traction mechanism is arranged on a horizontal guide rail.

[0013] Preferably, each traction mechanism includes a rising slider, a guide rail slider, a push rod motor, a ball hinge and a connecting rod;

[0014] The rising slider is embedded in the vertical guide rail and can move up and down along the vertical guide rail;

[0015] The guide rail slider is embedded in the horizontal guide rail and can move along the horizontal guide rail; the rising slider is connected to the guide rail slider through a ball hinge and a connecting rod;

[0016] The push rod motor is fixedly connected to the bottom of the lower rotating wheel, and the output shaft of the push rod motor is used to push the rising sliding block upward to the notch of the upper rotating wheel.

[0017] Preferably, the deformation mechanism further comprises four rotating parts;

[0018] Each guide rail slider is rotatably connected to a castor leg via a rotating member, and each castor leg can rotate around the corresponding guide rail slider in a horizontal plane.

[0019] Preferably, each head end rotating member is fixed on the guide rail slider; and it includes a humeral base joint, a micro motor and a connecting rod;

[0020] The humeral joint is arranged on the guide rail slider through a support frame, the output shaft of the micro motor is used to drive the humeral joint to rotate, the connecting rod passes through the through hole in the horizontal direction of the humeral joint, and its two ends are fixed to the head end of the wheel leg.

[0021] Preferably, each driving mechanism comprises a driving motor, a transmission gear and a gear bracket;

[0022] The center of the upper rotating wheel and the lower rotating wheel are both provided with through holes, and the inner wall of the through holes is provided with teeth. The output shaft of each driving motor is fixedly connected to a transmission gear, and the two transmission gears are respectively engaged with the teeth in the through holes on the upper rotating wheel and the lower rotating wheel;

[0023] Each transmission gear is fixed on the upper rotating wheel and the lower rotating wheel through a gear bracket.

[0024] Preferably, the deformation mechanism further comprises a steering gear; each caster leg comprises a femur, a tibia and a caster;

[0025] The two ends of the connecting rod are fixed to the head of the femur, the tail end of the femur is connected to the head end of the tibia, and the tail end of the tibia is connected to the foot wheel; the servo is used to drive the tibia to rotate around the head end of the femur, thereby changing the angle between the tibia and the femur.

[0026] Preferably, the deformation mechanism further comprises a guide device;

[0027] A guide device is provided between the tibia and the foot wheel, and the foot wheel is rotated around the tibia in a horizontal plane through the guide device.

[0028] Preferably, the deformation mechanism further includes a circular ring-shaped fixing bracket;

[0029] The annular fixed bracket is arranged between the upper rotating wheel and the lower rotating wheel. An annular track is provided on the upper surface of the annular fixed bracket. The upper rotating wheel is embedded in the annular groove of the annular track through the protrusion part of its lower surface, thereby realizing the rotational connection between the upper rotating wheel and the lower rotating wheel.

[0030] The beneficial effects of the present invention are:

[0031] The present invention provides a leg folding, telescopic and deformation mechanism, which aims to achieve the overall contraction of one leg, two legs or all legs of a quadruped wheel-legged robot through innovative design, so as to flexibly cope with uneven road surfaces and improve the flexibility and maneuverability of the quadruped wheel-legged robot.

[0032] The structure of the present invention has two telescopic conditions: the first is the telescopic extension of a single caster leg, and the second is the simultaneous telescopic extension of all four caster legs. When a single leg is telescopic, the corresponding traction mechanism is overlapped on the upper rotating wheel, and the upper rotating wheel drives the movement of one end of the corresponding traction mechanism, driving the head end transmission member of the caster leg connected to its other end to move horizontally along the corresponding horizontal and vertical slide rail assemblies, thereby achieving the telescopic extension of the corresponding caster leg. When the four caster legs are telescopic simultaneously, the four caster legs are overlapped on the lower rotating wheel, and the lower rotating wheel simultaneously drives the movement of one end of the traction mechanism, driving the head end transmission member of the caster leg connected to its other end to move horizontally along the corresponding horizontal and vertical slide rail assemblies, thereby achieving the simultaneous telescopic extension of all four caster legs. Therefore, the present invention can achieve the overall telescopic extension of a single leg, two legs, or all legs.

[0033] A double-layer rotating wheel is used to control the movement of the slider, wherein the top rotating wheel rotates to undertake the task of folding, expanding and contracting the legs. The rising slider moves up to the top rotating wheel, is fixed to it by a locking mechanism, and rotates with the wheel. At the same time, the guide rail slider is driven inward by the ball hinge and the connecting rod to achieve the contraction of a single leg, thereby improving the obstacle crossing ability of the wheel-legged robot. In addition, the present invention can also achieve the contraction of both legs or the whole. In addition to its application in improving obstacle crossing ability, the present invention also provides ideas for solving the problems of wheel sinking and terrain adaptability. When the wheel of the robot sinks in a soft sandy area, the present invention can gradually lift the wheel out by continuously contracting and stretching the legs, and at the same time, the wheel moves forward to gradually escape from the sunken area; the extension and retraction of the legs can change the center of mass of the robot, thereby improving the adaptability of the wheel-legged robot to complex terrains such as undulating roads and slopes.

[0034] The present invention adopts the advantages of the independent double-layer rotating wheel design: the two rotating wheels operate independently, and the upper rotating wheel is responsible for the folding, expanding and deforming work, so as to realize the overall contraction of one leg, two legs or all legs of the quadruped wheel-legged robot, thereby improving the flexibility and adaptability of the quadruped wheel-legged robot;

[0035] The advantages of the ball hinge connection mechanism design are: the connecting rod on the ball hinge can rotate in any direction within a certain cone angle. The upward movement of the rising slider will drive the guide slider inward, improving the efficiency of the robot's retraction action.

[0036] The advantages of using a guide rail structure design: it provides guidance and support for the slider in the guide rail, and improves the efficiency and stability of the wheel-legged robot in completing leg contraction.

[0037] Advantages of using the servo rocker arm femoral joint structure design: This structure changes the angle between the femoral joint and the tibia to ensure

[0038] Ensure that the center of gravity of the robot can be stable within the polygon formed by the foot ends, ensuring the stability of the robot when the legs are retracted. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the overall structure of the leg servo of the leg folding, extending, and retracting deformation mechanism of the quadruped wheel-leg composite robot in its initial state when working;

[0040] Figure 2 Schematic diagram of the self-locking mechanism;

[0041] Figure 3 This is a schematic diagram of the local details of the rising slider;

[0042] Figure 4 is the position diagram of the rotating mechanism;

[0043] Figure 5 It is the structural diagram of the rotating mechanism;

[0044] Figure 6 The figure shows the meshing of the rotating gear and the lower rotating wheel;

[0045] Figure 7 The diagram is a meshing diagram of the rotating gear and the upper rotating wheel;

[0046] Figure 8 This is a schematic diagram of the overall initial state of the leg servo of the leg folding, extending, and retracting deformation mechanism of the quadruped wheel-leg composite robot when it is not working;

[0047] Figure 9 This is a diagram of a single leg contraction state;

[0048] Figure 10 This is the state diagram of four legs contracting simultaneously;

[0049] Figure 11 This is a schematic diagram of the robot's single leg retraction process, where: Figure 11 (a) is a schematic diagram showing the locking of the ascending slider to the notch of the upper rotating wheel. Figure 11 (b) is a schematic diagram of the rotation of the upper rotating wheel. Figure 11 (c) is a schematic diagram of the upward slider rotating to drive the wheel leg to retract. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0052] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0053] Example:

[0054] Combine Figures 1 to 5 This embodiment describes a leg folding, extending, and retracting deformation mechanism for a quadruped wheel-leg composite robot suitable for operation in complex terrain. The deformation mechanism includes an upper rotating wheel 3, a lower rotating wheel 4, two driving mechanisms 5, four traction mechanisms 2, four horizontal and vertical slide rail assemblies 6, and four self-locking mechanisms 7.

[0055] The two driving mechanisms 5 are used to respectively drive the upper rotating wheel 3 and the lower rotating wheel 4 to rotate;

[0056] The upper rotating wheel 3 is stacked above the lower rotating wheel 4, and notches of the same shape are provided at the same position of the upper rotating wheel 3 and the lower rotating wheel 4, and the notches are evenly provided along the edges of the upper rotating wheel 3 and the lower rotating wheel 4; a horizontal and vertical slide rail assembly 6 is provided on the bottom surface of the lower rotating wheel 4 near each notch, and one end of each traction mechanism 2 moves in the vertical direction between the notch of the upper rotating wheel 3 and the notch of the lower rotating wheel 4 through the corresponding horizontal and vertical slide rail assembly 6, and the movement of one end of the traction mechanism 2 drives the head end transmission member of the caster leg 1 connected to the other end thereof to move in the horizontal direction of the corresponding horizontal and vertical slide rail assembly 6, thereby realizing the extension and retraction of the corresponding caster leg 1;

[0057] Each self-locking mechanism 7 is used to lock or unlock one end of the traction mechanism 2 that moves to the notch of the upper rotating wheel 3 .

[0058] Specifically, this embodiment is mainly aimed at realizing the folding, extending, and telescopic deformation of the legs of a quadruped wheel-leg composite robot, and therefore mainly focuses on the mechanical structure design and movement mode of the folding, extending, and telescopic deformation mechanism of the legs.

[0059] Rotating mechanism: The rotating mechanism includes an upper rotating wheel 3 and a lower rotating wheel 4. There is a fixed bracket 12 between the upper rotating wheel 3 and the lower rotating wheel 4. There is a circular track 12-1 on the upper surface of the fixed bracket 12. Figure 6As shown, the upper rotating wheel 3 is matched with the annular groove of the annular track 12-1 through the protrusion on its lower surface, thereby realizing the connection between the upper rotating wheel 3 and the lower rotating wheel 4. The upper rotating wheel 3 and the lower rotating wheel 4 are regular octagons with the same shape and size. There is a circular vacant part inside the turntable that is concentric with the regular octagon. The radius of the circular vacant part is half of the regular octagon, and the edge of the circular vacant part is gear-shaped and meshes with the transmission gear 5-2. The drive motor 5-1 and the transmission gear 5-2 are fixedly connected. The transmission gear 5-2 is meshed with the internal gear of the rotating mechanism. The power provided by the drive motor 5-1 drives the rotating mechanism to rotate through the transmission gear 5-2 to retract the legs. The gear bracket 5-3 is fixedly connected to the rotating mechanism.

[0060] Self-locking mechanism: Four self-locking mechanisms 7 are evenly distributed on the upper surface of the regular octagonal upper rotating wheel 4 of the rotating mechanism, and are fixedly connected to the upper rotating wheel 3. Figure 1 and 2 shown.

[0061] The horizontal guide rail, the vertical guide rail, the push rod motor and the rotating mechanism are fixedly connected by fixing bolts.

[0062] Limb part (wheel leg 1): Each leg is connected to the rotating mechanism through a self-locking mechanism 7, an ascending slider 2-1, a vertical guide rail 6-1, a guide rail slider 2-3, a horizontal guide rail 6-2, a ball hinge and a connecting rod 2-2 with the same structure.

[0063] The ball hinge and the ends of the connecting rod 2-2 are fixed to the rising slider 2-1 and the guide rail slider 2-3 by fixing bolts. The rising slider 2-1 is installed in the vertical guide rail 6-1 and can move up and down in the vertical plane along the vertical guide rail 6-1. In the initial state, the rising slider 2-1 is engaged with the edge of the lower rotating wheel 4, and the guide rail slider 2-3 is installed in the horizontal guide rail 6-2 and can move along the horizontal guide rail 6-2. In the initial state, the guide rail slider 2-3 is parked at the outermost end of the horizontal guide rail 6-2 near the femur 1-1.

[0064] The four legs of the leg folding, telescoping, and deforming mechanism are identical in structure and evenly distributed outside the rotating mechanism, meaning that any two adjacent legs form a 90° angle. Each leg consists of a femur 1-1 (the thigh), a tibia 1-2 (the calf), and a wheel 1-3 (the foot). A servo 8 is mounted at the uppermost end of the tibia 1-2, with a servo rocker arm 9 embedded in the lower end of the femur 1-1. The servo 8 and servo rocker arm 9 are connected by a shaft hole. The upper end of the femur 1-1 is connected to the guide rail slider 2-3 via a micromotor 10-2. The femur 1-2 can rotate about the humeral joint rotation axis 10-1 within an angle range of 0° to contact with the upper rotating wheel 3. Driven by the servo 8, the tibia 1-2 can rotate within a vertical plane to complete a planar folding motion. The tibia 1-2 rotates through an angle of 0° to 180°. Initially, the angle between the femur 1-2 and tibia 1-2 is approximately 45°.

[0065] like Figure 2 As shown, four fixed blocks 7-1 are provided on the upper rotating wheel. When single-leg contraction is performed, the spring 7-3 is compressed by the rising slider 2-1, and the locking rod 7-2 is stuck in the locking groove 2-1-1 to fix the rising slider 2-1 and the upper rotating wheel 3. The rising slider 2-1 rotates around the central axis along with the rotating mechanism, and drives the guide rail slider 2-3 to move inward along the horizontal guide rail 6-2 through the ball hinge and the connecting rod 2-2. When single-leg extension is performed, the push rod motor 2-4 pushes the rising slider 2-1 upward, and the spring 7-3 further compresses the locking rod 7-2. Figure 3 When the locking rod 7-2 is stuck in the first locking point 2-1-1-1 of the locking groove 2-1-1, self-locking is achieved. Figure 3 Slide out in the direction of the middle arrow to unlock.

[0066] The structure of the horizontal and vertical slide rail assembly 6 is described below:

[0067] Each horizontal and vertical slide rail assembly 6 includes a vertical guide rail 6-1 and a horizontal guide rail 6-2;

[0068] One end of the horizontal guide rail 6-2 is horizontally fixed to the bottom of the lower rotating wheel 4, and the other end of the horizontal guide rail 6-2 is a free end;

[0069] The vertical guide rail 6-1 is fixedly connected to the upper surface of one end of the horizontal guide rail 6-2, and the vertical guide rail 6-1 is embedded in the gap of the lower rotating wheel 4;

[0070] One end of each traction mechanism 2 is arranged on a vertical guide rail 6 - 1 , and the other end of each traction mechanism 2 is arranged on a horizontal guide rail 6 - 2 .

[0071] The following describes the structure of the traction mechanism 2:

[0072] Each traction mechanism 2 includes an ascending slider 2-1, a guide slider 2-3, a push rod motor 2-4, a ball hinge and a connecting rod 2-2;

[0073] The rising slider 2-1 is embedded in the vertical guide rail 6-1 and can move up and down along the vertical guide rail 6-1;

[0074] The guide rail slider 2-3 is embedded in the horizontal guide rail 6-2 and can move along the horizontal guide rail 6-2; the rising slider 2-1 is connected to the guide rail slider 2-3 through a ball hinge and a connecting rod 2-2;

[0075] The push rod motor 2-4 is fixedly connected to the bottom of the lower rotating wheel 4, and the output shaft of the push rod motor 2-4 is used to push the rising slider 2-1 upward to the gap of the upper rotating wheel 3.

[0076] The components included in this mechanism are further described below: It also includes four rotating members 10;

[0077] Each guide rail slider 2 - 3 is rotatably connected to a castor leg 1 via a rotating member 10 , and each castor leg 1 can rotate around the corresponding guide rail slider 2 - 3 in a horizontal plane.

[0078] The following describes the components of the rotating parts:

[0079] Each head end rotating member 10 is fixed on the guide rail slider 2-3; and it includes a humeral base joint 10-1, a micro motor 10-2 and a connecting rod 10-3;

[0080] The humeral joint 10-1 is set on the guide rail slider 2-3 through a support frame, and the output shaft of the micro motor 10-2 is used to drive the humeral joint 10-1 to rotate. The connecting rod 10-3 passes through the through hole in the horizontal direction of the humeral joint 10-1, and its two ends are fixed to the head end of the wheel leg 1.

[0081] Specifically, if Figure 5 As shown, the humeral joint 10-1 rotates, driving the humeral joint 10-1 and the connecting rod 10-3 to rotate simultaneously, thereby driving the wheel leg 1 connected to the connecting rod 10-3 to rotate. Figure 5 The direction of the middle arrow indicates a rotation direction of the humeral joint 10 - 1 , and the humeral joint 10 - 1 can also rotate in the opposite direction of the arrow.

[0082] The components of the drive mechanism are described below: Each drive mechanism 5 includes a drive motor 5-1, a transmission gear 5-2 and a gear bracket 5-3;

[0083] The center of the upper rotating wheel 3 and the lower rotating wheel 4 are both provided with through holes, and the inner wall of the through holes is provided with teeth. The output shaft of each driving motor 1 is fixedly connected to a transmission gear 2, and the two transmission gears 2 are respectively engaged with the teeth in the through holes on the upper rotating wheel 3 and the lower rotating wheel 4;

[0084] Each transmission gear 5 - 2 is fixed to the upper rotating wheel 3 and the lower rotating wheel 4 respectively through a gear bracket 5 - 3 .

[0085] The following describes the structure of the caster leg: the deformation mechanism further includes a steering gear 8; each caster leg 1 includes a femur 1-1, a tibia 1-2 and a caster 1-3;

[0086] The two ends of the connecting rod 10-3 are fixed to the head of the femur 1-1, the tail end of the femur 1-1 is connected to the head end of the tibia 1-2, and the tail end of the tibia 1-2 is connected to the wheel 1-3; the servo 8 is used to drive the tibia 1-2 to rotate around the head end of the femur 1-1, thereby changing the angle between the tibia 1-2 and the femur 1-1.

[0087] The components included in this mechanism are further described below: It also includes a circular fixed bracket 12;

[0088] The annular fixed bracket 12 is arranged between the upper rotating wheel 3 and the lower rotating wheel 4. The upper surface of the annular fixed bracket 12 is provided with an annular track 12-1. The upper rotating wheel 3 is embedded in the annular groove of the annular track 12-1 through the protrusion part of its lower surface, thereby realizing the rotational connection between the upper rotating wheel 3 and the lower rotating wheel 4.

[0089] Working principle:

[0090] The leg folding and extension deformation mechanism of the quadruped wheel-leg composite robot includes two extension states, one is single leg extension and the other is four legs extension at the same time. Figure 9 and Figure 10 Explain the working principles of the two telescopic states;

[0091] Combine Figure 9 Explain the principle of single leg extension:

[0092] Step A1: Motor driving: The push rod motor 2-4 is started, and the ascending slider 2-1 rises along the vertical track 6-1 until it is in the same plane as the upper rotating wheel 3.

[0093] Step A2: The ascending slider 2-1 is in place. The spring 7-3 in the self-locking mechanism 2-1 is compressed, and the locking rod 7-2 is locked into the locking groove 2-1-1 inside the ascending slider 2-1, so that the ascending slider 2-1 is engaged and fixed with the upper rotating wheel 3.

[0094] Step A3: The guide rail slider 2-3 moves inward. The guide rail slider 2-3 moves inward a small distance along the horizontal guide rail 6-2, and the legs move closer to the central rotation mechanism.

[0095] Step A4: Rotational Contraction. The drive motor 5-1 is activated, driving the transmission gear 5-2 and causing the upper rotating wheel 3 to rotate clockwise by a certain angle (greater than 0° and less than or equal to 40°). The ascending slider 2-1, which is engaged with the upper rotating wheel 3, also rotates clockwise by the same angle as the upper rotating wheel 3 rotates.

[0096] Step A5: Femoral segment retraction. As the ascending slider 2-1, embedded in the upper rotating wheel 3, rotates clockwise, the guide rail slider 2-3, pulled inward along the horizontal guide rail 6-2 by the ball hinge and connecting rod 2-2 connected to the ascending slider 2-1, drives the femoral segment 1-1 inward along the guide rail slider 2-3, approaching the rotating mechanism.

[0097] Step A6: Tibia Contraction: The servo 14 is activated, the tibia 16 is always kept perpendicular to the robot's motion plane, and the angle between the femur 1-1 and the tibia 1-2 is reduced.

[0098] Step A7: Contraction is completed. Driven by the micromotor 24, the humeroscapular joint 10 can rotate about its central axis in a plane parallel to the ground toward the rotation mechanism, so that the entire leg moves closer to the rotation mechanism, and the leg contraction is completed.

[0099] The following will explain how this mechanism can restore and extend the leg after the wheel-legged robot's single leg is retracted:

[0100] Step A8: The rotating mechanism is restored. The driving motor 5-1 is started, driving the transmission gear 5-2 to rotate and drive the ascending slider 2-1 to rotate along with the upper rotating wheel 3 in the counterclockwise direction back to the initial position.

[0101] Step A9: Leg extension. Since the ascending slider 2-1 is connected to the guide rail slider 2-3 via a ball hinge and its connecting rod 2-2, when the ascending slider 2-1 rotates counterclockwise, the guide rail slider 2-3 moves outward along the horizontal track 6-2. Simultaneously, the servo 8 is activated, and the femur 1-1 connected to the guide rail slider 2-3 extends, while the tibia 1-2 extends.

[0102] Step A10: The robot leg returns to its initial state. The push rod motor 2-4 is activated, compressing the spring 7-3 in the self-locking mechanism 7, causing the locking rod 7-2 to move out of the locking slot 2-1-1 along the inclined surface of the locking slot 2-1-1. The locking rod 7-2 separates from the ascending slider 2-1, and the spring 7-3 gradually returns to its original state. The push rod motor 2-4 drives the ascending slider 2-1 to slowly descend to the lower rotating wheel 4, preventing the ascending slider 2-1 from suddenly descending and colliding with the lower rotating wheel 4. The robot leg then returns to its initial state.

[0103] Combine Figure 10 , explaining the principle of simultaneous extension and retraction of four legs:

[0104] Step B1: The rotating mechanism is started. The driving motor 5-1 driving the lower rotating wheel 4 is started, and the lower rotating wheel 4 rotates clockwise. The four ascending sliders 2-1 in the same plane as the lower rotating wheel 4 rotate along with the lower rotating wheel 4.

[0105] Step B2: Lowering the center of mass. Because the four guide rails 2-3 are connected to the ascending slider 2-1 via ball hinges and their connecting rods 2-2, they simultaneously move inward when the ascending slider 2-1 rotates clockwise. Furthermore, because this process is directly driven by the lower rotating wheel 4, the interference between the ball hinges and connecting rods 2-2 and the rotating mechanism is minimal. This increases the distance the guide rails 2-3 can move inward, significantly lowering the robot's center of mass.

[0106] Step B3: Limb contraction is complete. The tibia 1-2 remains perpendicular to the ground, and the four servos 8 operate simultaneously, reducing the angle between the femur 1-1 and the tibia 1-2. Limb contraction is complete.

[0107] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with other described embodiments.

Claims

1. A leg folding, extending, and retracting deformation mechanism of a quadruped wheel-leg composite robot, characterized in that: The deformation mechanism comprises an upper rotating wheel (3), a lower rotating wheel (4), two driving mechanisms (5), four traction mechanisms (2), four horizontal and vertical slide rail assemblies (6) and four self-locking mechanisms (7); Two driving mechanisms (5) are used to respectively drive the upper rotating wheel (3) and the lower rotating wheel (4) to rotate; The upper rotating wheel (3) is stacked above the lower rotating wheel (4), and notches of the same shape are provided at the same position of the upper rotating wheel (3) and the lower rotating wheel (4), and the notches are evenly provided along the edges of the upper rotating wheel (3) and the lower rotating wheel (4); a horizontal and vertical slide rail assembly (6) is provided on the bottom surface of the lower rotating wheel (4) near each notch, and one end of each traction mechanism (2) moves in the vertical direction between the notch of the upper rotating wheel (3) and the notch of the lower rotating wheel (4) through the corresponding horizontal and vertical slide rail assembly (6), and the movement of one end of the traction mechanism (2) drives the head end transmission member of the caster leg (1) connected to the other end thereof to move in the horizontal direction of the corresponding horizontal and vertical slide rail assembly (6), thereby realizing the extension and retraction of the corresponding caster leg (1); Each self-locking mechanism (7) is used to lock or unlock one end of the traction mechanism (2) that moves to the notch of the upper rotating wheel (3).

2. The leg folding, extending and retracting deformation mechanism of a quadruped wheel-leg composite robot according to claim 1, characterized in that: Each horizontal and vertical slide rail assembly (6) comprises a vertical guide rail (6-1) and a horizontal guide rail (6-2); One end of the horizontal guide rail (6-2) is horizontally fixed to the bottom of the lower rotating wheel (4), and the other end of the horizontal guide rail (6-2) is a free end; The vertical guide rail (6-1) is fixedly connected to the upper surface of one end of the horizontal guide rail (6-2), and the vertical guide rail (6-1) is embedded in the notch of the lower rotating wheel (4); One end of each traction mechanism (2) is arranged on a vertical guide rail (6-1), and the other end of each traction mechanism (2) is arranged on a horizontal guide rail (6-2).

3. The leg folding, extending and retracting deformation mechanism of a quadruped wheel-leg composite robot according to claim 2, characterized in that: Each traction mechanism (2) comprises an ascending slider (2-1), a guide rail slider (2-3), a push rod motor (2-4), a ball hinge and a connecting rod (2-2); The ascending slider (2-1) is embedded in the vertical guide rail (6-1) and can move up and down along the vertical guide rail (6-1); The guide rail slider (2-3) is embedded in the horizontal guide rail (6-2) and can move along the horizontal guide rail (6-2); the rising slider (2-1) and the guide rail slider (2-3) are connected via a ball hinge and a connecting rod (2-2); The push rod motor (2-4) is fixedly connected to the bottom of the lower rotating wheel (4), and the output shaft of the push rod motor (2-4) is used to push the ascending slider (2-1) upward to the notch of the upper rotating wheel (3).

4. The leg folding, extending, and retracting deformation mechanism of a quadruped wheel-leg composite robot according to claim 3, characterized in that: The deformation mechanism further includes four rotating parts (10); Each guide rail slider (2-3) is rotatably connected to a castor leg (1) via a rotating member (10), and each castor leg (1) can rotate around the corresponding guide rail slider (2-3) in a horizontal plane.

5. The leg folding, extending and retracting deformation mechanism of a quadruped wheel-leg compound robot according to claim 4, characterized in that: Each head-end rotating member (10) is fixed on a guide rail slider (2-3); and comprises a humeral base joint (10-1), a micro motor (10-2) and a connecting rod (10-3); The humeral joint (10-1) is arranged on the guide rail slider (2-3) via a support frame, the output shaft of the micro motor (10-2) is used to drive the humeral joint (10-1) to rotate, the connecting rod (10-3) passes through a through hole in the horizontal direction of the humeral joint (10-1), and its two ends are fixed to the head end of the wheel leg (1).

6. The leg folding, extending and retracting deformation mechanism of a quadruped wheel-leg compound robot according to claim 1, characterized in that: Each driving mechanism (5) comprises a driving motor (5-1), a transmission gear (5-2) and a gear bracket (5-3); A through hole is provided at the center of the upper rotating wheel (3) and the lower rotating wheel (4), and teeth are provided on the inner wall of the through hole. The output shaft of each driving motor (5-1) is fixedly connected to a transmission gear (5-2), and the two transmission gears (5-2) are respectively engaged with the teeth in the through holes on the upper rotating wheel (3) and the lower rotating wheel (4); Each transmission gear (5-2) is fixed on the upper rotating wheel (3) and the lower rotating wheel (4) respectively through a gear bracket (5-3).

7. The leg folding, extending, and retracting deformation mechanism of a quadruped wheel-leg compound robot according to claim 5, characterized in that: The deformation mechanism further includes a steering gear (8); each wheel leg (1) includes a femur (1-1), a tibia (1-2) and a wheel (1-3); Both ends of the connecting rod (10-3) are fixed to the head of the femur (1-1), the tail end of the femur (1-1) is connected to the head end of the tibia (1-2), and the tail end of the tibia (1-2) is connected to the foot wheel (1-3); the steering gear (8) is used to drive the tibia (1-2) to rotate around the head end of the femur (1-1), thereby changing the angle between the tibia (1-2) and the femur (1-1).

8. The leg folding, extending, and retracting deformation mechanism of a quadruped wheel-leg compound robot according to claim 7, characterized in that: The deformation mechanism further includes a guide device (11); A guide device (11) is provided between the tibia (1-2) and the foot wheel (1-3), and the foot wheel (1-3) is rotated around the tibia (1-2) in a horizontal plane through the guide device (11).

9. The leg folding, extending, and retracting deformation mechanism of a quadruped wheel-leg compound robot according to claim 1, characterized in that: The deformation mechanism further includes a circular ring-shaped fixing bracket (12); The annular fixed bracket (12) is arranged between the upper rotating wheel (3) and the lower rotating wheel (4); an annular track (12-1) is provided on the upper surface of the annular fixed bracket (12); the upper rotating wheel (3) is embedded in the annular groove of the annular track (12-1) through the protrusion on the lower surface thereof, thereby realizing the rotational connection between the upper rotating wheel (3) and the lower rotating wheel (4).

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