Wheel-foot robot

Abstract

The invention relates to a wheel-foot robot. The wheel-foot robot comprises a robot body, two symmetrically-arranged wheel-foot assemblies and at least four driven omnidirectional wheels. Each wheel foot assembly comprises a driving walking wheel driven by a hub motor and a Chebyshev four-connecting-rod mechanism connected with the machine body and the driving walking wheel. And the power input end of the connecting rod mechanism is driven by a hip joint motor arranged on the machine main body. In the walking state, the driving walking wheels and the driven omnidirectional wheels make contact with the ground together, and stable multi-point supporting is formed. When the jumping action is executed, the hip joint motor drives the Chebyshev four-connecting-rod mechanism to guide the driving walking wheel to do approximately linear motion towards the ground so as to complete efficient stepping on the ground. The efficient jumping function is achieved through a simplified single-motor-driven connecting rod structure, the walking stability is enhanced through multi-wheel supporting, and the structural complexity and cost are effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of robotics, and more particularly to a wheeled legged robot. Background Technology

[0002] Ground mobile robot technology is an important branch of robotics. Wheeled robots are widely used due to their advantages of high speed and energy efficiency on flat ground, but their mobility is poor, making it difficult to overcome obstacles or adapt to complex terrain. In contrast, legged robots mimic biological walking patterns, possessing superior terrain adaptability and obstacle-crossing capabilities, but they are usually accompanied by inherent drawbacks such as complex structure, high energy consumption, and slow movement speed. To combine the advantages of both, hybrid wheel-legged robots have emerged, especially biwheeled and legged robots, which, due to their relatively compact structure, have become a key research direction for balancing mobility efficiency and obstacle-crossing capabilities.

[0003] Existing biwheeled robots typically rely on complex leg joint designs to achieve dynamic obstacle-crossing functions such as jumping or leaping. For example, their legs often include independent hip and knee joints, each driven by an independent servo motor. When performing a jumping motion, the control system needs to precisely coordinate the timing and output torque of multiple joint motors to simulate the knee flexion and force exertion process in a living organism. This multi-motor cooperative drive scheme not only significantly increases the robot's hardware cost, overall weight, and system power consumption, but also places extremely high demands on the complexity and robustness of the control algorithm. The kinematic and dynamic model solutions are very complex, making real-time control difficult. Furthermore, to maintain balance during wheeled movement, most of these biwheeled robots employ a self-balancing control strategy similar to an inverted pendulum, which places stringent requirements on sensor accuracy and control response speed. Their stability is easily compromised by external impacts or uneven ground. Therefore, how to effectively improve the dynamic obstacle-crossing ability and wheeled walking stability of biwheeled robots while simplifying the mechanical structure and drive method is a pressing technical challenge in this field. Summary of the Invention

[0004] To help solve the technical problems existing in the prior art, the present invention provides a wheeled robot, which aims to innovatively combine the Chebyshev four-bar linkage with the wheeled structure. While ensuring the robot has stable and efficient wheeled walking ability, it can achieve efficient linear jumping by using a hip joint motor to drive the linkage mechanism, thereby simplifying the drive structure, reducing control complexity and improving the robot's dynamic obstacle-crossing performance.

[0005] This invention discloses a wheeled robot, comprising: The main body of the fuselage is constructed from a carbon fiber frame, and hip joint motors are mounted on opposite sides of the main body of the fuselage. Two wheel assemblies are respectively mounted on opposite sides of the main body of the fuselage; At least four driven omnidirectional wheels are located on opposite sides of the bottom of the main body of the fuselage and are distributed in front of and behind the driving wheels; Each of the wheel assemblies includes: Active walking wheels are located at the bottom of the main body of the fuselage; Hub motors are connected to the active walking wheels. The hub motors on opposite sides of the main body drive each active walking wheel to rotate at the same or different speeds, thereby enabling the robot to walk in a straight line or turn. The Chebyshev four-bar linkage has its power input end hinged upward to the main body of the machine and driven to the output shaft of the hip joint motor, and its near-linear output end connected downward to the drive wheel; In the walking state, the active walking wheel and the driven omnidirectional wheel are in contact with the ground together; When performing a jumping motion, the hip joint motor drives the Chebyshev four-bar linkage to swing downwards and guides the active walking wheel to move in a near-linear motion toward the ground.

[0006] It is understood that the wheeled robot of the present invention first includes a main body, which is preferably constructed using a carbon fiber frame combined with aluminum tubes and three-dimensional connectors to achieve a balance between lightweight and high rigidity. On opposite sides of the main body, a hip joint motor is symmetrically positioned as a power source, providing driving torque for subsequent leg movements. Correspondingly, the robot's two wheeled leg components are also mounted on opposite sides of the main body and connected to the corresponding hip joint motors. To enhance the robot's stability during wheeled movement, at least four driven omnidirectional wheels are also provided at the bottom of the main body. These driven omnidirectional wheels are distributed on both sides of the bottom of the main body, located in front of and behind the traveling direction of the active walking wheels (described later), forming a stable multi-point support base.

[0007] Furthermore, the internal structure of each wheel assembly is crucial for realizing the core functions of this invention. Each wheel assembly has an active walking wheel at its end, which integrates a hub motor. When the robot performs wheeled movement tasks, the control system can independently or collaboratively control the hub motors on both sides. When the hub motors on both sides drive the active walking wheel to rotate at the same speed, the robot achieves straight-line movement; when the hub motors on both sides drive the active walking wheel to rotate at different speeds (i.e., differential speed), with the auxiliary support of the driven omnidirectional wheel, the robot can flexibly achieve turning movement.

[0008] Crucially, the transmission mechanism connecting the main body of the machine to the drive wheels employs a unique Chebyshev four-bar linkage. The power input end of this Chebyshev four-bar linkage is structurally hinged upwards to the main body of the machine and power-driven to the output shaft of the hip joint motor. The near-linear output end of this linkage connects downwards to the location of the drive wheels. This mechanical design allows the rotational motion of the hip joint motor to be geometrically transformed through the Chebyshev four-bar linkage into a near-linear reciprocating motion at the end of the drive wheels.

[0009] Based on the above structural layout, this wheeled robot possesses two core states of collaborative operation. In its normal walking state, the robot's center of gravity is low, and its active walking wheel and four driven omnidirectional wheels all contact the ground, forming a six-wheel support structure. This posture not only provides excellent stability for high-speed wheeled movement but also allows the robot to adapt to a certain degree of ground unevenness. In scenarios requiring jumping, such as overcoming obstacles, the control system drives the hip joint motors on both sides to rotate rapidly, thereby causing the Chebyshev four-bar linkage to swing downwards. During this process, the characteristics of this linkage guide the active walking wheel to perform a rapid, nearly linear push-off motion towards the ground. This near-linear motion efficiently converts the torque output from the hip joint motors into a vertical force on the ground, generating sufficient ground reaction force to propel the entire robot body upwards to overcome obstacles.

[0010] According to a wheeled robot of the present invention, the Chebyshev four-bar linkage includes a linkage positioning plate, a thigh support, a lower leg support, and a connecting rod, all made of carbon fiber. The linkage positioning plate is fixedly disposed on one side of the main body of the robot. The thigh support and the connecting rod have the same straight length and are respectively hinged upward to opposite ends of the linkage positioning plate, and the hinged end of the thigh support on the linkage positioning plate is drively connected to the output shaft of the hip joint motor. The active walking wheel is hinged to the lower end of the lower leg support. The ends of the connecting rod and the thigh support away from the linkage positioning plate are respectively hinged to the lower leg support, and the hinged ends of both and the lower leg support are respectively away from the active walking wheel. The hip joint motor drives the thigh support and the connecting rod to swing downward synchronously, thereby driving the active walking wheel to move in a near-linear direction toward the ground.

[0011] According to a wheeled robot of the present invention, the lower leg supports are inclined and form a certain angle with the thigh support and the connecting rod, and the angle is directed towards the front of the main body. The lower leg supports are inclined in a straight line downward from the angle position to ensure that the Chebyshev four-bar linkage drives the robot to move forward during the robot's jump.

[0012] According to a wheeled robot of the present invention, an upper limit block and a lower limit block are provided on one side of the linkage positioning plate, which surround the output shaft of the hip joint motor; the upper limit block and the lower limit block respectively limit and contact the thigh support at a preset upper rotation limit position and a preset lower rotation limit position; wherein, when the thigh support rotates upward to the limit position of the upper limit block, the active walking wheel and the driven omnidirectional wheel jointly contact the ground; when the thigh support rotates downward to the limit position of the lower limit block, the active walking wheel raises the driven omnidirectional wheel and the main body of the robot.

[0013] According to a wheeled leg robot of the present invention: a wrist bearing is provided at the hinge point between the thigh support and the lower leg support; the wrist bearing bears the radial and axial loads between the thigh support and the lower leg support to prevent radial and axial looseness at the hinge point between the thigh support and the lower leg support; a deep groove ball bearing is provided at the hinge point between the thigh support and the connecting rod positioning plate; the deep groove ball bearing bears the radial and axial loads between the thigh support and the connecting rod positioning plate to prevent radial and axial looseness at the hinge point between the thigh support and the connecting rod positioning plate.

[0014] According to a wheeled robot of the present invention, an elbow guide wheel is provided at the hinge point between the lower leg support and the connecting rod; the elbow guide wheel is located on the front side of the Chebyshev four-bar linkage so as to contact the obstacle in front before the Chebyshev four-bar linkage.

[0015] According to a wheeled robot of the present invention, it further includes a plurality of body guide wheels; each of the body guide wheels is located on the front and rear sides of the main body, so as to contact the obstacles in front and behind before the main body.

[0016] According to a wheeled robot of the present invention, each of the driven omnidirectional wheels is a Mecanum wheel made of plastic, and each of the Mecanum wheels is distributed at the four diagonal positions of the main body.

[0017] According to a wheeled robot of the present invention, optical axes are coaxially connected between two Mecanum wheels located on the front side of the main body and between two Mecanum wheels located on the rear side of the main body; it also includes a plurality of Mecanum wheel fixing plates in the shape of right angle triangles; the two diagonal positions on the hypotenuse of each Mecanum wheel fixing plate are respectively hinged to the main body and the central axis of each Mecanum wheel by bearings; and shock absorbers are respectively connected between the right angle position of each Mecanum wheel fixing plate and the main body.

[0018] According to a wheeled robot of the present invention, the main body includes an outer clamping plate and an inner clamping plate located on opposite sides thereon; hip joint motors on both sides of the main body are respectively located between the outer clamping plate and the inner clamping plate; and a locking rod is connected between the outer clamping plate and the inner clamping plate, and the locking rod is connected and fixed to the outer clamping plate and the inner clamping plate and clamps the hip joint motor; wherein, one end of the shock absorber is hinged to a right angle position of the Mecanum wheel fixing plate, and the other end is hinged to the locking rod.

[0019] The technical advantages of the wheeled legged robot of the present invention include: First, the robot uses a single hip joint motor on one side in conjunction with a Chebyshev four-bar linkage, replacing the complex structure of traditional wheeled robots that require multiple degrees of freedom motors (such as hip joint pitch and hip joint roll) to work together. This greatly simplifies the mechanical structure and drive system, effectively reducing manufacturing costs and the overall weight of the robot.

[0020] Secondly, by utilizing the inherent characteristic of the Chebyshev four-bar linkage that can convert rotational motion into near-linear motion, the robot's leg-end push-off force acts more directly on the ground when performing a jumping action, resulting in higher energy transfer efficiency. This leads to stronger jumping ability with the same motor power and simplifies the kinematic control algorithm for jumping actions.

[0021] Furthermore, the multi-point support system, consisting of the active walking wheel and multiple driven omnidirectional wheels, provides the robot with static and dynamic stability far exceeding that of traditional two-wheeled self-balancing robots. Especially during high-speed movement and turning, it can effectively prevent tipping and improve the reliability of movement.

[0022] Finally, this solution seamlessly integrates the stability of wheeled movement with the obstacle-crossing ability of legged jumping into the same mechanical structure, eliminating the need for additional mode switching devices and achieving a high degree of functional integration and efficient synergy. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a partial structural diagram of the present invention; Figure 4 This is a three-dimensional structural diagram from another perspective of the present invention; Figure 5 This is a three-dimensional structural diagram from another perspective of the present invention.

[0025] Figure Labels 100. Main body of the machine; 101. Hip joint motor; 102. Guide wheel of the machine body; 103. Outer clamping plate; 104. Inner clamping plate; 105. Locking rod; 200. Wheel and foot assembly; 201. Active walking wheel; 202. Hub motor; 210. Chebyshev four-bar linkage; 211. Linkage positioning plate; 212. Thigh support; 213. Lower leg support; 214. Linkage rod; 215. Upper limit block; 216. Lower limit block; 217. Wrist assembly bearing; 218. Deep groove ball bearing; 219. Elbow guide wheel. 300. Driven omnidirectional wheel; 301. Optical shaft; 302. Mecanum wheel mounting plate; 303. Shock absorber. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] like Figures 1 to 5 As shown, this embodiment provides a wheeled robot, which includes a main body 100, two wheel and leg components 200 symmetrically arranged on both sides of the main body 100, and at least four driven omnidirectional wheels 300 arranged at the bottom of the main body 100.

[0028] Specifically, the main body 100 serves as the platform for the entire robot. To achieve overall lightweighting while ensuring structural rigidity, its frame is preferably constructed from high-strength carbon fiber sheets and aluminum tubing. For example... Figure 1 and Figure 4 As shown, a high-torque hip motor 101 is fixedly mounted on each of the left and right opposite sides of the main body 100. These two hip motors 101 serve as the core power source, providing driving torque for the subsequent wheel-foot assembly 200 to perform leg movements such as jumping.

[0029] Accordingly, two wheel-foot assemblies 200, serving as the robot's core motion actuators, are respectively mounted on both sides of the main body 100 and connected to the hip joint motors 101 on the corresponding sides. To ensure high stability of the robot in wheeled movement mode, four driven omnidirectional wheels 300 are also provided at the bottom of the main body 100. Figure 2As shown, the four driven omnidirectional wheels 300 are located on the front and rear sides of the bottom of the fuselage body 100, and are spatially distributed in front of and behind the active walking wheels 201 described later, thus forming a stable rectangular support base.

[0030] like Figure 2 and Figure 3 As shown, each wheel assembly 200 has an active walking wheel 201 at its end. This active walking wheel 201 is located at the bottom of the main body 100, and its surface can be covered with anti-slip rubber to increase friction with the ground. Inside the active walking wheel 201, a hub motor 202 is integrated. This hub motor 202 forms a direct drive connection with the active walking wheel 201. When the robot needs to move on wheels, the control system inside the main body 100 can independently control the hub motors 202 on both sides. When the hub motors 202 on both sides drive their respective active walking wheels 201 to rotate at the same speed, the robot can achieve straight-line movement; while when the control system creates a speed difference between the hub motors 202 on both sides, the robot can flexibly turn.

[0031] The key technical feature of this embodiment is that the mechanical structure connecting the main body 100 and the active walking wheel 201 adopts a Chebyshev four-bar linkage 210. The power input end of this Chebyshev four-bar linkage 210 is structurally hinged upwards to the main body 100 and connected to the output shaft of the hip joint motor 101 for power transmission. Simultaneously, the near-linear output end of the Chebyshev four-bar linkage 210 is connected downwards to the active walking wheel 201. This ingenious linkage design can efficiently convert the rotational motion output by the hip joint motor 101 into a near-linear reciprocating motion trajectory at the end of the active walking wheel 201 through the geometric constraints of the mechanism itself.

[0032] Based on the above structure, this wheeled robot possesses two core motion modes for collaborative operation. The first is the walking state, in which the robot's posture is low, and its two active walking wheels 201 and four driven omnidirectional wheels 300 are stably in contact with the ground, forming a six-wheel support structure. This multi-point support layout provides the robot with excellent static and dynamic stability, enabling it to achieve high-speed, smooth wheel rolling.

[0033] The second mode is the jumping motion. When the robot needs to cross an obstacle, the control system drives the hip motors 101 on both sides to rotate rapidly, either synchronously or asynchronously. The rotation of the hip motors 101 causes the Chebyshev four-bar linkage 210 to swing rapidly downwards. During this process, the kinematic characteristics of the Chebyshev four-bar linkage 210 guide the active walking wheel 201 at its end to perform a powerful push-off motion towards the ground along an approximately straight trajectory. This near-linear motion maximizes the conversion of the torque output by the hip motors 101 into a linear force on the ground, thereby obtaining a sufficiently large ground reaction force to propel the entire robot body 100 upwards to achieve the obstacle-crossing function.

[0034] Furthermore, the specific structure of the Chebyshev four-bar linkage 210 includes a link positioning plate 211, a thigh support 212, a lower leg support 213, and a connecting rod 214. To minimize rotational inertia and overall mass while maintaining high structural rigidity, the link positioning plate 211, thigh support 212, lower leg support 213, and connecting rod 214 are all made of carbon fiber sheet. The link positioning plate 211 is fixedly mounted on one side of the main body 100, serving as the frame support for the four-bar linkage. The thigh support 212 and connecting rod 214 are designed to have the same straight length and are respectively hinged upwards to opposite ends of the link positioning plate 211 via bearings. To input motor power into the mechanism, the hinged end of the thigh support 212 on the link positioning plate 211 is coaxially connected to the output shaft of the hip joint motor 101, thus making the thigh support 212 the driving link.

[0035] Subsequently, to form a closed-loop linkage circuit, the ends of the connecting rod 214 and the thigh support 212, away from the connecting rod positioning plate 211, are respectively hinged to the upper part of the calf support 213. In this structural layout, the active walking wheel 201 is hinged to the bottom end of the calf support 213, and both hinge points of the thigh support 212 and the connecting rod 214 with the calf support 213 are located above the active walking wheel 201. This specific geometric topology allows the output point trajectory at the bottom of the calf support 213 to approach a straight line when the hip joint motor 101 drives the thigh support 212 to swing in a circular motion and simultaneously rotates the connecting rod 214 downward.

[0036] To achieve efficient obstacle crossing and jumping capabilities, the hip joint motor 101 drives the aforementioned linkage assembly to rotate downwards synchronously, guiding the active walking wheel 201 to perform a high-intensity near-linear impact motion towards the ground. Because the Chebyshev four-bar linkage 210 converts rotational power into a downward linear force, this structure allows the torque of the hip joint motor 101 to be applied more directly to the ground, thereby generating a stronger instantaneous reaction force. This design not only simplifies the kinematic trajectory control of the robot during jumps but also avoids energy loss due to multi-degree-of-freedom joint coordination errors, significantly improving the robot's linear push-off efficiency and landing stability when performing complex dynamic movements.

[0037] Furthermore, the lower leg support 213 is designed with an inclined spatial layout, and the lower leg support 213, thigh support 212, and connecting rod 214 all form a specific preset angle, with this angle pointing towards the front of the main body 100. The lower leg support 213 extends in a straight downward and backward tilt from this angle position. When the hip joint motor 101 is working, its output torque drives the thigh support 212 to swing around its hinge point, and through the lower leg support 213, it drives the connecting rod 214 to generate coupled motion. Due to the backward tilt of the lower leg support 213, when the Chebyshev four-bar linkage 210 pushes downward, the active walking wheel 201 applies a downward and backward force to the ground. According to Newton's third law, the ground will give the robot a forward and upward reaction force. The resulting physical effect is that the robot can gain forward displacement during a jump by relying solely on the drive of the hip joint motors, and can ensure the structural strength and dynamic efficiency of the Chebyshev four-bar linkage 210 in the process of driving the robot forward, thereby enhancing the robot's obstacle-crossing maneuverability.

[0038] In some embodiments, in order to accurately limit the motion amplitude of the wheel assembly 200 and prevent damage to the mechanical structure due to excessive rotation, an upper limit block 215 and a lower limit block 216 are provided on one side of the linkage positioning plate 211. The upper limit block 215 and the lower limit block 216 are arranged around the output shaft of the hip joint motor 101, and are designed to make limiting contact with the thigh support 212 at a preset upper rotation limit position and a preset lower rotation limit position, respectively, through mechanical interference.

[0039] Specifically, when the hip joint motor 101 drives the thigh support 212 to rotate upward until it touches the limit position of the upper limit block 215, the Chebyshev four-bar linkage 210 is in a retracted state. At this time, the active walking wheel 201 and the driven omnidirectional wheel 300 on the bottom of the robot body are in contact with the ground. This process allows the robot to enter a low center of gravity crawling posture. The rigid limit of the upper limit block 215 ensures that the active walking wheel 201 will not jump excessively due to ground impact during high-speed movement. The combined support of multiple wheels greatly enhances the robot's anti-tipping ability and driving stability in complex dynamic environments.

[0040] When the thigh support 212 rotates downward to the limiting position of the lower limit block 216, the Chebyshev four-bar linkage 210 extends to its maximum extent towards the ground, and the active walking wheel 201 lifts the main body 100 upward through a ground-pushing action, causing the driven omnidirectional wheel 300 to leave the ground. At this time, the lower limit block 216 not only clearly defines the end point of the leg extension stroke, but also uses a mechanical stop to bear part of the reverse load generated by the body's gravity, thereby reducing the stall torque of the hip joint motor 101 when maintaining a standing posture. Through this mechanical limiting design, the robot can reliably switch between different motion modes, ensuring not only the consistency of the jumping stroke, but also effectively protecting the motor and its reduction mechanism from damage by overrunning impact forces through physical hard limiting.

[0041] Furthermore, to address the potential joint displacement and looseness issues that may arise in multi-link mechanisms during high-speed motion or sudden force changes, this embodiment incorporates specific mechanical optimizations for the hinge joints of the Chebyshev four-bar linkage 210. A specially designed cup bearing 217 is installed at the hinge point between the thigh support 212 and the lower leg support 213. Since this hinge point is located at the intersection of forces during leg movement trajectory changes, it is simultaneously subjected to vertical impact loads and lateral overturning moments during jumps or supporting heavy objects. The cup bearing 217's "radial positioning + axial limiting" function effectively supports both radial and axial loads between the thigh support 212 and the lower leg support 213. This technique aims to eliminate axial movement and radial looseness at the hinge point caused by assembly tolerances or long-term wear, thereby ensuring the tightness of the connection between the supports and ultimately achieving high-precision maintenance of the leg movement trajectory and a significant improvement in structural rigidity.

[0042] On the other hand, a deep groove ball bearing 218 is additionally provided at the active power input hinge point between the thigh support 212 and the linkage positioning plate 211. Considering that the thigh support 212 is directly connected to the output shaft of the hip joint motor 101, this hinge point is not only the core part of torque output, but also the main support point bearing the weight of the robot body. By using the deep groove ball bearing 218 to jointly support the radial and axial loads generated at this point, radial runout or axial swaying of the thigh support 212 during high-speed rotation or force-induced swinging can be effectively avoided. Accordingly, the application of the deep groove ball bearing 218 ensures the smoothness and consistency of power transmission, and guarantees the geometric stability of the Chebyshev four-bar linkage 210 at the physical level, thereby avoiding motion oscillations caused by loose hinge points and improving the overall operating accuracy and mechanical life of the robot under complex working conditions.

[0043] Furthermore, regarding motion protection in the Chebyshev four-bar linkage 210, an elbow guide wheel 219 is provided at the hinge point between the lower leg support 213 and the connecting rod 214. Since this hinge point is typically located at the outermost edge of the structure during the linkage's swing, the elbow guide wheel 219 is positioned at the front of the Chebyshev four-bar linkage 210's movement, serving as a physical protective contact point for the robot's leg structure. When the robot approaches obstacles such as walls, steps, or people, or when performing a stair-descent maneuver, the elbow guide wheel 219 can contact the obstacle before other links in the Chebyshev four-bar linkage 210. By utilizing the rotational characteristics of the elbow guide wheel 219 to transform the potentially hard sliding friction between the linkage and the environment into rolling friction, this design effectively reduces motion resistance caused by structural interference, thereby avoiding the risk of the robot tipping over due to its leg joints colliding with obstacles. Correspondingly, the elbow guide wheel 219 not only protects the carbon fiber support from scratches and damage, but also significantly improves the robot's efficiency and safety when performing complex obstacle crossing tasks and moving in narrow spaces.

[0044] Furthermore, to enhance the robot's safety in dynamic environments and provide physical protection for its core components, the wheeled robot also includes several body guide wheels 102. Specifically, each body guide wheel 102 is symmetrically arranged on the front and rear edges of the main body 100, typically located at the four corners or the outermost protruding positions of the body frame. These body guide wheels 102 are positioned to slightly protrude horizontally from the edges of the carbon fiber frame of the main body 100.

[0045] The technical purpose of this structural layout is to enable the guide wheels 102 to contact obstacles in front of or behind the robot's path before the main body 100. When the robot approaches a wall or person due to inertia, detection delay, or turning in a confined space, the guide wheels 102 will collide with the obstacle first. Because the guide wheels 102 have rolling characteristics, this design transforms the potential hard impact friction between the main body 100 and the obstacle into tangential rolling friction between the guide wheels and the obstacle surface. This physical change significantly reduces the normal impact force experienced by the robot at the moment of impact, effectively protecting the brittle carbon fiber frame and the integrated precision electronic control module from structural damage. Correspondingly, the design of the guide wheels 102 not only improves the robot's obstacle avoidance redundancy and safety in complex environments but also avoids drastic deviations in the trajectory due to impact, ensuring the robot can glide smoothly along the edge of obstacles and expanding its applicability in confined space scenarios such as industrial inspection.

[0046] In some embodiments, in order to achieve multi-point stable support while also meeting the requirements for overall lightweight design, each driven omnidirectional wheel 300 is specifically designed as a Mecanum wheel made of plastic. Specifically, four Mecanum wheels are symmetrically distributed at four diagonal positions on the bottom of the main body 100.

[0047] The purpose of using plastic to manufacture the driven omnidirectional wheels 300 is to leverage the low density of engineering plastics to significantly reduce the overall mass of the auxiliary walking system while maintaining structural strength, thereby effectively reducing overall machine inertia and improving energy efficiency. Correspondingly, four Mecanum wheels are positioned at the four diagonal corners of the main body 100 to create a rectangular support base with the largest possible span. When the robot is in a low-center-of-gravity crawling state, this arrangement ensures that the center of gravity of the main body 100 is always projected within the support polygon formed by the four Mecanum wheels and two active walking wheels 201, effectively preventing the robot from tipping over or falling when moving at high speed on uneven ground or when the center of gravity changes dynamically, significantly enhancing motion stability.

[0048] Utilizing the structural characteristic that the edge roller axis of the Mecanum wheel forms a specific angle with the wheel axle axis, when the hub motors 202 on both sides of the main body 100 drive the active walking wheels 201 in opposite directions to generate steering torque, the four Mecanum wheels can cooperate to generate a lateral displacement component, thereby achieving zero-radius spin motion of the robot. This process avoids the lateral drag resistance generated by traditional fixed driven wheels when turning, not only improving the smoothness of the steering action, but also enabling the robot to complete flexible posture adjustments in narrow and confined spaces, meeting the high mobility requirements of scenarios such as industrial inspection or warehousing and transportation.

[0049] In another specific application scenario, to further optimize the structural stiffness of the driven omnidirectional wheel 300 system and introduce buffering and shock absorption functions, the robot features a specially designed mounting structure for the Mecanum wheels. Specifically, the two Mecanum wheels located at the front of the main body 100 and the two Mecanum wheels located at the rear of the main body 100 are coaxially connected by a high-rigidity optical axis 301. The technical purpose of this optical axis 301 is to physically couple the two Mecanum wheels on the same side into a rigid whole, thereby effectively resisting single-wheel deflection caused by uneven ground or lateral impact forces, and significantly enhancing the lateral structural strength of the entire driven wheel system.

[0050] Furthermore, the mounting structure also includes several Mecanum wheel fixing plates 302 in the shape of right-angled triangles. At two diagonal positions on the hypotenuse of each Mecanum wheel fixing plate 302, it is hinged to the side plate of the fuselage body 100 and the central axis of the corresponding Mecanum wheel via rolling bearings such as flange bearings or thrust needle roller bearings. This double-hinge connection method aims to ensure that the Mecanum wheel fixing plate 302 can swing slightly up and down around the hinge point on the fuselage body 100, thereby giving the driven omnidirectional wheel 300 system a certain degree of ground adaptability.

[0051] Subsequently, to effectively buffer the aforementioned swaying process, shock absorbers 303 are connected between the right-angle position of each Mecanum wheel fixing plate 302 and the main body 100. When the robot jumps and lands from a height or travels on rough terrain, the driven omnidirectional wheel 300 will be the first to contact the ground and bear the impact load. At this time, the impact force will be transmitted to the shock absorber 303 through the Mecanum wheel fixing plate 302. The shock absorber 303 can absorb and dissipate most of the impact energy through its own elastic deformation and damping effect. This process not only protects precision components such as the hip joint motor 101 and hub motor 202 from instantaneous overload impact, but also avoids severe vibration or secondary bouncing of the body caused by rigid collisions, thereby ensuring the robot's landing stability and rapid recovery of motion posture during complex dynamic processes.

[0052] In some embodiments, to further enhance the installation rigidity of the power module and optimize the load distribution of the entire machine, the fuselage body 100 adopts a double-layer clamping plate reinforcement structure. Specifically, the fuselage body 100 includes an outer clamping plate 103 and an inner clamping plate 104 located on opposite sides of it, and these two clamping plates are arranged in parallel to form the lateral frame of the fuselage body 100. In this structural layout, the hip joint motors 101 on both sides of the fuselage body 100 are respectively nested and installed between the corresponding outer clamping plate 103 and inner clamping plate 104.

[0053] Subsequently, to ensure that the high-torque hip joint motor 101 does not shift when performing high-intensity jumping movements or being subjected to severe external impacts, the outer clamping plate 103 and the inner clamping plate 104 are physically connected by several locking rods 105. These locking rods 105 are connected in series and fixed to the outer clamping plate 103 and the inner clamping plate 104, and the two layers of clamping plates are tightly clamped to the outer shell of the hip joint motor 101 by axial preload. The technical purpose of this clamping and fixing scheme is to use the large contact area of ​​the clamping plates to evenly distribute the reaction torque generated by the hip joint motor 101 during operation to the carbon fiber frame of the main body 100, thereby effectively avoiding damage to the motor mounting position caused by local stress concentration and significantly improving the structural safety of the power drive unit under extreme working conditions.

[0054] Furthermore, the locking rod 105 is structurally reused as a key load-bearing hub in the suspension system. Specifically, one end of the shock absorber 303 is hinged to the right angle of the Mecanum wheel fixing plate 302, while the other end is directly hinged to the corresponding locking rod 105. This process deeply integrates the suspension system with the motor fixing structure. By fixing the support end of the shock absorber 303 to the locking rod 105, the ground impact force received by the driven omnidirectional wheel 300 can be directly applied to the high-strength locking rod 105 through the shock absorber 303, and jointly borne by the inner and outer clamping plate systems. This force path design aims to minimize the load transmission chain, reduce structural flutter caused by multi-stage transitions, and make the absorption of impact energy at the moment of landing more direct and efficient. This simplifies the spatial layout of the robot while ensuring rapid convergence and stability of the robot's motion posture in complex terrain.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wheeled-legged robot, characterized in that, include: The main body (100) is constructed from a carbon fiber frame, and hip joint motors (101) are mounted on opposite sides of the main body (100). Two wheel assemblies (200) are respectively mounted on opposite sides of the fuselage body (100); At least four driven omnidirectional wheels (300) are provided on opposite sides of the bottom of the fuselage body (100) and distributed in front of and behind the driving wheels (201); Each of the wheel shank assemblies (200) includes: Active walking wheels (201) are located at the bottom of the main body (100); The hub motor (202) is connected to the active walking wheel (201). The hub motors (202) on both sides of the main body (100) drive each active walking wheel (201) to rotate at the same speed or different speeds, so as to drive the robot to walk in a straight line or turn. The Chebyshev four-bar linkage (210) has its power input end hinged upward to the main body (100) and driven to the output shaft of the hip joint motor (101), and its near-linear output end connected downward to the drive wheel (201). In the walking state, the active walking wheel (201) and the driven omnidirectional wheel (300) are in contact with the ground together; When performing a jumping action, the hip joint motor (101) drives the Chebyshev four-bar linkage (210) to swing downward and guide the active walking wheel (201) to move in a near-linear direction toward the ground.

2. The wheeled robot according to claim 1, characterized in that, The Chebyshev four-bar linkage (210) includes a linkage positioning plate (211), a thigh support (212), a lower leg support (213), and a connecting rod (214), all made of carbon fiber. The connecting rod positioning plate (211) is fixedly installed on one side of the main body (100); the thigh support (212) and the connecting rod (214) have the same straight length and are respectively hinged upward to the opposite ends of the connecting rod positioning plate (211), and the hinge end of the thigh support (212) on the connecting rod positioning plate (211) is connected to the output shaft of the hip joint motor (101); The active walking wheel (201) is hinged to the lower end of the lower leg support (213); The ends of the connecting rod (214) and the thigh support (212) away from the connecting rod positioning plate (211) are respectively hinged to the calf support (213), and the hinge ends of both and the calf support (213) are respectively away from the active walking wheel (201). The hip joint motor (101) drives the thigh support (212) and the connecting rod (214) to swing downwards synchronously, thereby driving the active walking wheel (201) to move in a near-linear direction toward the ground.

3. The wheeled robot according to claim 2, characterized in that, The lower leg support (213) is inclined and forms a certain angle with the thigh support (212) and the connecting rod (214), and the angle is directed towards the front of the main body (100). The lower leg support (213) is inclined straight down and backward from the angle position to ensure that the Chebyshev four-bar linkage (210) drives the robot to move forward during the robot's jump.

4. The wheeled robot according to claim 2, characterized in that, The link positioning plate (211) is provided with an upper limit block (215) and a lower limit block (216) surrounding the output shaft of the hip joint motor (101) on one side. The upper limit block (215) and the lower limit block (216) respectively limit the contact with the thigh support (212) at the preset upper rotation limit position and the preset lower rotation limit position. in, When the thigh support (212) rotates upward to the limit position of the upper limit block (215), the active walking wheel (201) and the driven omnidirectional wheel (300) jointly contact the ground; When the thigh support (212) rotates downward to the limit position of the lower limit block (216), the active walking wheel (201) raises the driven omnidirectional wheel (300) and the main body (100).

5. The wheeled robot according to claim 2, characterized in that: The hinge point between the thigh support (212) and the calf support (213) is provided with a wrist bearing (217); the wrist bearing (217) bears the radial and axial loads between the thigh support (212) and the calf support (213) to avoid radial and axial looseness at the hinge point between the thigh support (212) and the calf support (213); The hinge point between the thigh support (212) and the connecting rod positioning plate (211) is provided with a deep groove ball bearing (218). The deep groove ball bearing (218) bears the radial and axial loads between the thigh support (212) and the connecting rod positioning plate (211) to avoid radial and axial looseness at the hinge point between the thigh support (212) and the connecting rod positioning plate (211).

6. The wheeled robot according to claim 2, characterized in that, An elbow guide wheel (219) is provided at the hinge point between the lower leg support (213) and the connecting rod (214). The elbow guide wheel (219) is located in front of the Chebyshev four-bar linkage (210) so as to contact the obstacle in front before the Chebyshev four-bar linkage (210).

7. The wheeled robot according to claim 1, characterized in that, It also includes several fuselage guide wheels (102); Each of the fuselage guide wheels (102) is located on the front and rear sides of the fuselage body (100) respectively, so as to contact the obstacles in front and behind before the fuselage body (100).

8. The wheeled robot according to claim 1, characterized in that, Each of the driven omnidirectional wheels (300) is a Mecanum wheel made of plastic, and each of the Mecanum wheels is distributed at the four diagonal positions of the main body (100).

9. The wheeled robot according to claim 8, characterized in that, Optical axes (301) are coaxially connected between the two Mecanum wheels located on the front side of the fuselage body (100) and between the two Mecanum wheels located on the rear side of the fuselage body (100). It also includes several Mecanum wheel fixing plates (302) in the shape of right triangles. The two diagonal positions on the hypotenuse of each Mecanum wheel fixing plate (302) are respectively hinged to the fuselage body (100) and the central axis of each Mecanum wheel by bearings; Furthermore, each of the Mecanum wheel fixing plates (302) is connected to a shock absorber (303) at a right angle to the fuselage body (100).

10. The wheeled robot according to claim 9, characterized in that, The fuselage body (100) includes an outer clamping plate (103) and an inner clamping plate (104) located on opposite sides thereon. The hip joint motors (101) on both sides of the main body (100) are located between the outer clamping plate (103) and the inner clamping plate (104), respectively; Furthermore, a locking rod (105) is connected between the outer clamping plate (103) and the inner clamping plate (104), and the locking rod (105) is connected and fixed to the outer clamping plate (103) and the inner clamping plate (104) and clamps the hip joint motor (101). One end of the shock absorber (303) is hinged to the right angle position of the Mecanum wheel fixing plate (302), and the other end is hinged to the locking rod (105).

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