Mars rover wheel based on rolling grass

Abstract

A Mars rover wheel based on rolling grass belongs to the technical field of deep space exploration and is formed by fixing two single wheels together, each single wheel comprises a wheel face and a spoke, and the spoke is provided with a central shaft tube; the wheel face is of a double-layer structure, the inner ring is of a parallelogram taper hole structure, the windward deflection angle can capture wind energy on the surface of Mars according to the Venturi effect, and therefore the wind energy can be utilized to reduce energy consumption. The protrusions of the outer ring effectively enhance the traction force of the wheel on the soil of Mars, and the risks of slipping and sinking are reduced. The crossed surfaces of the spokes close to the central shaft tube are filled with cones; the spokes are distributed in a radial shape, and the concentrated load is decomposed into a distributed micro stress field. The spoke is a structural bionic structure of a filiform parting structure of the rollastonia; on the premise that the bearing capacity is guaranteed, the mass of the system is reduced, the driving energy consumption is reduced by means of wind power, the impact resistance and the pressure resistance are remarkably improved, and the system is suitable for the Mars environment.

Description

Technical Field

[0001] This invention belongs to the field of deep space exploration technology, specifically relating to a Mars rover wheel based on tumbleweed. Background Technology

[0002] As a core component of the Mars rover's mobility system, the wheels' structural design and material properties must withstand the harsh challenges of Martian terrain, intense dust storms (wind speeds of 2-25 m / s), and extreme diurnal temperature variations (-100-20°C). Considering the requirements of the Mars exploration mission and the unique Martian environment (such as complex dune terrain, periodic dust storms, extreme diurnal temperature variations, and low atmospheric pressure), the rover wheels must balance lightweight design, high load-bearing capacity, and adaptability to various terrains within a limited energy supply. Based on the biomimetic design of tumbleweed filamentous pores and a low-friction rolling mechanism, through fractal spoke topology optimization, hollow hub gradient reinforcement, and a wind-engine coordinated drive system, the wheel's mass can be significantly reduced, its compressive strength increased, and passive propulsion achieved using Martian seasonal winds, thus reducing drive energy consumption. Therefore, it is necessary to design a wheel based on tumbleweed biomimetic technology to address these challenges. Summary of the Invention

[0003] The purpose of this invention is to solve the problems of large overall mass, insufficient ability to utilize Martian wind power, and poor maneuverability of Martian wheels, and to provide a Martian rover wheel based on tumbleweed.

[0004] A Mars rover wheel based on tumbleweed consists of two individual wheels fixed together. Each individual wheel includes a wheel surface and spokes, with the spokes having a central axle tube. The wheel surface has a double-layer structure, consisting of an inner ring and an outer ring. The outer ring is fixed to the outer surface of the inner ring. The inner ring has parallelogram-shaped conical holes spaced apart, and the outer ring is composed of several protrusions arranged laterally at intervals. The parallelogram cone-shaped aperture is larger on the outside and smaller on the inside. After the wind enters through the parallelogram cone-shaped aperture, it is concentrated and accelerated according to the Venturi effect. The concentrated and accelerated wind helps to drive the spokes, thereby realizing the concentrated and effective utilization of wind energy on the Martian surface, so as to reduce energy consumption. The raised sections on the outer ring effectively enhance the wheel's traction on Martian soil, reduce the risk of slipping and sinking, and improve maneuverability.

[0005] The spokes are composed of several X-shaped spokes arranged at intervals. Each X-shaped spoke has a cross point, and the two outer ends of each X-shaped spoke intersect with the outer ends of the adjacent X-shaped spokes. Multiple cross points interlock to disperse stress, decomposing concentrated loads into distributed micro-stress fields. Stress is dispersed through fractal structure to avoid stress concentration. The small cross surfaces near the hub are filled to increase support capacity and reduce the impact of stress concentration, thus meeting the rigidity requirements of the Mars rover. This spoke structure is a biomimetic design inspired by the filamentous fractal structure of tumbleweed.

[0006] The protrusions of one single wheel are staggered with those of another single wheel.

[0007] The four corners of the parallelogram-shaped conical hole are rounded.

[0008] Each of the X-shaped spokes bends outwards with the same arc.

[0009] The space between the intersection of each X-shaped spoke and the surface of the central shaft tube is filled with a cone, which bends with the curvature of the X-shaped spoke. The function of the cone is to prevent stress concentration at the intersection 211.

[0010] The surface of the cone is smooth, which reduces the obstruction to airflow and also helps to reduce wear.

[0011] The beneficial effects of this invention are: The wheel surface adopts a double-layer structure, consisting of an inner ring and an outer ring. The inner ring has a parallelogram-shaped conical hole structure, designed with a windward deflection angle, i.e., the inner surface is inclined. Based on the Venturi effect, it processes and utilizes wind energy on the Martian surface—concentrating and accelerating it. This not only helps the concentrated wind drive the spokes, generating upward lift on the wheel, but also increases the wind throughput, avoiding direct resistance from wind hitting the non-perforated wheel surface, thus helping to reduce energy consumption. The outer ring has spaced protrusions, effectively enhancing the wheel's traction on Martian soil and reducing the risk of slippage and sinking. The spokes are radially distributed, and the branches are interlocked at nodes to disperse stress, decomposing concentrated loads into distributed micro-stress fields. The fractal structure disperses stress and avoids stress concentration. The spoke structure is biomimetic to the filamentous fractal structure of tumbleweed. This invention, while ensuring load-bearing capacity, reduces system mass with its parallelogram-shaped conical hole perforated structure, reduces driving energy consumption by utilizing wind power, and significantly improves impact resistance and pressure resistance, making it suitable for the Martian environment. Attached Figure Description

[0012] Figure 1 This is a perspective view of an embodiment of the present invention; Figure 2 This is a front view of an embodiment of the present invention; Figure 3This is a side view of an embodiment of the present invention; Figure 4 This is a three-dimensional schematic diagram of the single-unit wheel of the present invention; Figure 5 This is a three-dimensional schematic diagram of the wheel surface of the single wheel of the present invention; Figure 6 This is a three-dimensional schematic diagram of the spokes of the single wheel of the present invention; Figure 7 This is a three-dimensional schematic diagram of the spoke root structure of the single wheel of the present invention; Figure 8 This is a top view of the cone of the present invention; Figure 9 This is a front view of the cone of the present invention; Figure 10 This is a right view of the cone of the present invention; Figure 11 This is a front view of the parallelogram-shaped conical hole of the present invention; Figure 12 for Figure 11 Sectional view along line B-B in the middle; Figure 13 for Figure 11 The C-C sectional view in the figure. Detailed Implementation

[0013] like Figures 1 to 13 As shown, a Mars rover wheel based on tumbleweed consists of two individual wheels A fixed together. Each individual wheel A includes a wheel surface 1 and spokes 2, with the spokes 2 having a central axle tube 3. The wheel surface 1 has a double-layer structure, consisting of an inner ring 11 and an outer ring 12. The outer ring 12 is fixed to the outer surface of the inner ring 11. The inner ring 11 is provided with parallelogram-shaped conical holes 111 spaced apart. The outer ring 12 is composed of several protrusions 121 arranged laterally at intervals. like Figure 11 , Figure 12 and Figure 13 As shown, the parallelogram cone aperture 111 is larger on the outside and smaller on the inside. After the wind enters through the parallelogram cone aperture 111, it captures and accelerates the wind energy on the Martian surface according to the Venturi effect, so as to reduce energy consumption by utilizing the wind energy. The protrusions 121 on the outer ring 12 effectively enhance the traction of the wheels on Martian soil, reduce the risk of slipping and sinking, and improve passability.

[0014] The spokes 2 are composed of several X-shaped spokes 21 arranged at intervals. Each X-shaped spoke 21 has an intersection point 211. The two outer ends of each X-shaped spoke 21 intersect with the outer ends of the adjacent X-shaped spokes 21. Multiple intersection points interlock to disperse stress, decompose concentrated loads into distributed micro-stress fields, and disperse stress through fractal structure to avoid stress concentration. This spoke structure is a biomimetic design based on the filamentous fractal structure of tumbleweed.

[0015] Each of the X-shaped spokes 21 bends outwards with the same arc.

[0016] The space between the intersection point 211 of each X-shaped spoke 21 and the surface of the central shaft tube 3 is filled with a cone 4. The cone 4 bends with the curvature of the X-shaped spoke 21. The function of the cone 4 is to prevent stress concentration at the intersection point 211.

[0017] The surface of the cone 4 is smooth, which reduces the obstruction to airflow and has a certain effect of reducing wear.

[0018] The protrusions 121 of one single wheel A are staggered with the protrusions 121 of another single wheel A.

[0019] The four corners of the parallelogram conical hole 111 are rounded.

[0020] Design principle of the invention: The parallelogram cone hole 111 design, with a large outer layer and a small inner layer, creates a tapered and inclined air duct, which concentrates the wind, making the force from the wind more concentrated and more efficient than when the force is distributed evenly. It also allows the wheel spokes to leverage the force. Therefore, the main function of the parallelogram cone hole 111 is to guide the airflow, rather than simply to reduce the weight of the wheel.

[0021] The four corners of the parallelogram conical hole 111 are rounded to provide a smooth transition and to avoid the phenomenon of "stress concentration leading to fatigue cracks, which then gradually propagate from the high point and eventually cause the structure to break".

[0022] 3. The inner opening of the parallelogram tapered hole 111 is constricted and does not block the wind. It applies the "Venturi effect": when a fluid (such as air) flows through a constricted pipe, its flow velocity increases and its pressure decreases. This is the Venturi effect. Therefore, the constricted design is equivalent to a constricted pipe.

[0023] It not only doesn't "block the wind," but it actually accelerates the passage of wind. Once it enters the contraction section, the flow rate increases dramatically. When the wind is in the opposite direction to the direction of travel, the high-speed airflow can pass through the holes more efficiently, rather than violently impacting the solid wheel surface and causing huge resistance. Therefore, it actually "drains the wind" rather than "blocks the wind," thus achieving the utilization of wind energy.

[0024] 4. The inclined surface inside the parallelogram cone hole 111 mainly changes the direction of the wind and acts as a buffer to concentrate the wind. The Venturi effect (increased flow velocity and decreased pressure) itself does not directly generate thrust. The area where it occurs (contraction section) is a low-pressure area. What it generates on the wheel is actually an inward (towards the wheel center) suction force, rather than a forward thrust.

[0025] 5. Vortex Enhancement Effect: The "vortex enhancement effect" typically occurs at the airflow outlet. When a high-speed jet is ejected from the inner nozzle, it shears against the surrounding relatively stationary air, inevitably generating vortices. What needs to be avoided is the "side effect" of energy loss. Vortices can produce some effects such as enhanced adhesion or enhanced mixing, but the essence of this wheel's design lies in "directional airflow guidance" and "Venturi acceleration," thereby generating the aforementioned thrust. In terms of force, the role of vortices is more about reducing drag than boosting, thus reducing the pressure difference between the inside and outside air. Regarding the effects of eddies, the greatest benefit is "enhanced self-cleaning ability." Spark dust is extremely fine and easily adheres to equipment. The eddies formed at the outlet of the hollow structure can remove spark dust accumulated in the recesses of the wheel surface, preventing dust accumulation from affecting wheel movement, such as balance or increasing friction.

[0026] 6. Because the intersection surface near the hub is too small, stress concentration occurs at the intersection point. Therefore, this area is filled. A curved cone is used for filling, which not only fits the small intersection surface, but also has a smooth surface without sharp edges, reducing obstruction to airflow and reducing wear to some extent.

[0027] When airflow is directed to the spokes, because the spokes are curved, the airflow that is blocked by the spokes needs to travel a longer distance along the spokes, while the airflow that is not blocked by the fractal spokes travels a relatively shorter path. This creates a velocity difference between the upper and lower surfaces of the spokes. According to Bernoulli's principle, the higher the velocity of the fluid along a streamline, the lower its static pressure. Therefore, the pressure at each branch of the spokes is lower than the pressure of the airflow directly to the side, creating a pressure difference. This pressure difference ΔP acts on the entire surface of the spokes, and its resultant force is a force perpendicular to the direction of the incoming flow, which is aerodynamic lift ("lift" here is an aerodynamic term, and its direction is perpendicular to the direction of the airflow, not necessarily "upward"; on the rotating wheel here, the direction of this force is constantly changing). Aerodynamic lift can be divided into radial and tangential components, with the tangential component being an effective assist. Multiplying the tangential component by the radius of the wheel produces a torque that propels the wheel to roll. This torque directly helps the motor overcome resistance, thereby saving energy.

[0028] The wind energy utilization mechanism of this structure is the result of the combined action of the parallelogram cone hole 111 and the spokes of the fractal structure that mimics tumbleweed. First, the parallelogram cone hole 111 organizes and pre-accelerates the incoming airflow, and then guides the airflow to the fractal spokes at a concentrated and accelerated point. Then, the fractal spokes, which have an airfoil-like curved surface, are the core secondary structure for wind energy conversion. They act as miniature sails, and their special curvature creates a pressure difference in the airflow, thereby generating a propulsive force (the horizontal component of lift) in the same direction as the wheel's forward movement. This force acts directly on the spokes, effectively reducing the torque required by the drive motor, thus achieving energy saving. This two-stage design of "guide the flow first, then actuate" highly simulates the natural process of tumbleweed branching network capturing wind energy and converting it into rolling kinetic energy, which is the key to achieving efficient wind energy utilization.

Claims

1. A Mars rover wheel based on tumbleweed, characterized in that: It is composed of two single wheels (A) fixed together. The single wheel (A) includes a wheel surface (1) and a spoke (2). The spoke (2) has a central axle tube (3). The wheel surface (1) has a double-layer structure, consisting of an inner ring (11) and an outer ring (12). The outer ring (12) is fixed to the outer surface of the inner ring (11). The inner ring (11) has parallelogram-shaped conical holes (111) spaced apart. The outer ring (12) is composed of several protrusions (121) arranged laterally. The parallelogram-shaped conical holes (111) are larger on the outside and smaller on the inside. The spokes (2) are composed of several X-shaped spokes (21) arranged at intervals. Each X-shaped spoke (21) has a cross point (211), and the two outer ends of each X-shaped spoke (21) cross the outer ends of the adjacent X-shaped spokes (21).

2. The Mars rover wheel based on tumbleweed according to claim 1, characterized in that: The protrusions (121) of one single wheel (A) are staggered with the protrusions (121) of another single wheel (A).

3. A Mars rover wheel based on tumbleweed according to claim 1, characterized in that: The four corners of the parallelogram conical hole (111) are rounded.

4. A Mars rover wheel based on tumbleweeds according to claim 1, characterized in that: Each of the X-shaped spokes (21) bends outwards with the same arc.

5. A Mars rover wheel based on tumbleweed according to claim 1, characterized in that: The space between the intersection (211) of each X-shaped spoke (21) and the surface of the central shaft tube (3) is filled with a cone (4).

6. A Mars rover wheel based on tumbleweed according to claim 5, characterized in that: The cone (4) bends along the arc of the X-shaped spokes (21).

7. A Mars rover wheel based on tumbleweed according to claim 5, characterized in that: The surface of the cone (4) is smooth.

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