Wheel foot vehicle

Abstract

The invention discloses a wheel-foot vehicle combining a wheel type mode and a foot type mode. The wheel-foot vehicle comprises bionic legs, a hydraulic driving system, non-pneumatic tires and an anti-rolling vehicle frame. The bionic legs comprise thighs and shanks to enhance obstacle crossing ability, the hydraulic driving system provides strong power and sufficient displacement for the three-stage hydraulic columns, the non-pneumatic tires are polyurethane flexible spoke type tires to reduce maintenance, and the anti-rolling frame guarantees safety of the vehicle and passengers. The designed wheel-foot vehicle aims at improving the trafficability and maneuverability of complex terrains, through an innovative wheel-foot conversion mechanism, the capacity of fast wheel-type running on a flat road surface and foot-type obstacle crossing on a rugged ground is achieved, and high adaptability and operation flexibility are achieved.

Description

Technical Field

[0001] The present invention relates to vehicle structure design, and particularly to a wheel-legged vehicle, belonging to the field of automotive design. Background Art

[0002] Nearly half of the land on the earth has complex terrains. Traditional wheeled vehicles often show insufficient obstacle-crossing ability when facing rough or obstacle-rich terrains, which limits their applications in specific environments. To solve this problem, the design of wheel-legged vehicles has been gradually explored. Such vehicles combine the advantages of wheeled and legged locomotion modes, and can maintain high-speed progress on flat roads while crossing obstacles through the lifting and movement of the legs. In recent years, with the rapid development of robot technology and material science, the design of wheel-legged vehicles has been continuously optimized. Multimodal wheel-legged composite special vehicles have strong terrain adaptability and obstacle-crossing ability, high energy utilization rate, and strong stability.

[0003] At present, the wheel design scheme of wheel-legged composite vehicles still uses traditional pneumatic tires. Such a choice cannot guarantee the traffic safety of wheel-legged composite vehicles in unstructured terrains. Therefore, it is necessary to introduce non-pneumatic tires in the design of the wheels of wheel-legged composite vehicles. Based on the above idea, the composite configuration vehicle applying flexible spoke non-pneumatic tires can maintain an efficient and stable driving state in unstructured terrains and can also achieve fast movement on ordinary roads, thus greatly improving the efficiency of accident rescue, material transportation and other tasks. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: under the condition of unstructured terrains, to invent a special vehicle with high passability, high mobility and high safety, which can achieve fast movement on ordinary roads and efficient and stable driving on unstructured terrains through wheeled mode and legged mode, and reduce the occurrence of safety accidents caused by tire damage with the help of non-pneumatic tires.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A wheel-legged vehicle, characterized in that it includes a bionic leg (1), a hydraulic drive system (2), a non-pneumatic tire (3), and a roll cage (4). The bionic leg (1) consists of a thigh (11) and a calf (12). The positioning shaft of the thigh (11) is connected to the positioning hole of the calf (12). The length of the bionic leg is designed according to the proportion of the legs of most quadruped mammals. The length ratio of the thigh to the calf of the bionic leg is obtained based on the maximum movement space that the leg can reach. The hydraulic drive system (2) is a three-stage hydraulic system. The hydraulic drive system (2) is installed on the positioning shaft between the thigh (11) and the calf (12) and the positioning shaft between the thigh (11) and the chassis. In the structure of the hydraulic drive system, the maximum range and the minimum range should ensure a large movement range of the leg. The non-pneumatic tire adopts a flexible spoke unit form and consists of a water lily type unit support body array. The non-pneumatic tire (3) includes a support body (31) and a tread (32). The non-pneumatic tire is installed on one side of the calf (12) through a wheel hub. The tread (32) is adhesively cooperated with the support body (31). The roll cage is designed in an oval shape, and the cross-section of the pillar is circular.

[0007] Further, the bionic leg adopts a full-elbow type leg design scheme. In the bionic leg (1), the thigh (11) and the calf (12) are made of carbon steel. The upper end of the thigh (11) is connected to the chassis, and the shaft end at the lower end of the thigh (11) is assembled with the hole section at the upper end of the calf (12).

[0008] Further, the hydraulic drive system (2) is made of carbon steel. One hydraulic drive system is arranged between the thigh (11) and the chassis and between the thigh (11) and the calf (12) respectively. The specific installation positions are as follows: it is connected at 450 mm behind the chassis along the chassis at the fixed position of the upper end of the thigh (11) and at 250 mm along the thigh at the fixed position of the thigh (11) and the chassis, and it is connected at 350 mm along the thigh at the fixed position of the thigh (11) and the chassis and at 450 mm along the calf at the fixed position of the thigh (11) and the calf (12). In order to maintain consistency, the hydraulic drive systems between the thigh (11) and the calf (12) and between the thigh and the chassis use hydraulic cylinders of the same size and range. The shortest range of the hydraulic pressure is 225 mm, the maximum range is 625 mm, and the range of a single-stage hydraulic pressure is 0 - 200 mm.

[0009] Further, the non-pneumatic tire (3) is made of high-modulus polyurethane material. Each water lily support body of the non-pneumatic tire (3) is used as a structural unit, and its arrangement is a circular arrangement. The radius of the tire is 301 mm. The tread (32) is adhesively cooperated with the support body (31) and fixed on the wheel hub, and is cooperated with the hole section at the lower end of the calf (12) through the shaft end of the wheel hub.

[0010] Further, the roll cage (4) is made of carbon steel, and the roll cage is designed in an oval shape with a cylindrical support part.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] (1) By designing the structure of the wheel-legged vehicle, the present invention has strong mobility, strong load capacity, strong adjustment ability, and excellent safety performance. When the vehicle is traveling on a regular road surface, it can adopt a wheeled movement mode to achieve a higher movement speed. When the wheels cannot be used for rolling on unstructured terrain, it can adopt a legged movement mode or a combined wheel-legged movement mode. The bionic leg adopts a full-elbow leg structure, which makes each elbow joint of the leg located at the rear, effectively avoiding the collision between the knee joint and the obstacle in front of it, thus improving the passability and stability in complex terrains. At the same time, the unified joint form is relatively easy to control, which helps to simplify the control system of the robot, improve the movement efficiency and response speed, and reduce the manufacturing cost and maintenance difficulty. The hydraulic drive system adopts three-stage hydraulics, which has the advantages of compact structure, small volume, and light weight, and can accurately adjust the working pressure of the system through a pressure control valve at different pressure stages to ensure that the flow rate and pressure meet the working requirements.

[0013] (2) The flexible spoke non-pneumatic tire is made of polyurethane material, which has excellent durability and puncture resistance and is suitable for use in extreme environments or complex terrains.

[0014] (3) Through simulation analysis, it is obtained that for the wheel-legged vehicle to cross a horizontal gully terrain with a span of 650 mm, adopting the leg movement sequence of the right hind leg - right front leg - left hind leg - left front leg can ensure that the center of gravity of the vehicle always moves forward. The swing amplitude of the vehicle in the left-right direction during the crossing process always remains within 30 mm, which is relatively small compared to the vehicle size. It has good stability during the gully crossing process. The maximum span of the horizontal gully that an ordinary vehicle can cross is 4 / 3r, and the tire radius is 301 mm. Therefore, the theoretical maximum span of the horizontal gully that the vehicle can cross is 401.33 mm. In the simulation, the wheel-legged vehicle can cross a 650-mm horizontal gully. From this, it can be concluded that the vehicle's passability in crossing horizontal gullies has increased by 61.96%. For a vertical step terrain with a height of 700 mm, adopting the leg movement sequence of the left front leg - right front leg - left hind leg - right hind leg and keeping the body posture inclined during the leg movement process so that the movement space of the front and hind legs tends to be consistent, there is a more abundant leg movement space for obstacle crossing. The swing amplitude of the vehicle in the left-right direction during the obstacle crossing process is maintained within 37 mm, which is relatively small compared to the vehicle size. It has good stability during the gully crossing process. The maximum height of the vertical obstacle that an ordinary wheeled vehicle can pass through is 4 / 3r, and the tire radius is 301 mm. Theoretically, the maximum height of the vertical obstacle that an ordinary vehicle can cross is 401.33 mm. In the simulation, the height of the vertical obstacle that the wheel-legged vehicle can cross is 700 mm. In terms of obstacle crossing ability, it has increased by 74.42% compared to traditional vehicles. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the overall structure of the wheel-legged vehicle;

[0016] Figure 2 It is a schematic diagram of the leg structure of the wheel-legged vehicle;

[0017] Figure 3 It is a schematic diagram of the legged mode of the wheel-legged vehicle. Detailed Implementation Manner

[0018] The present invention proposes a wheel-legged vehicle. The following further describes the present invention in conjunction with the drawings and specific embodiments.

[0019] As Figure 1 shown, the wheel-legged vehicle mainly consists of a bionic leg, a hydraulic drive system, a non-pneumatic tire, and a roll cage. The wheel-legged vehicle also includes an interior, etc., which will not be introduced in detail.

[0020] As Figure 2As shown in the figure, the bionic leg 1 is designed with reference to the leg structure of quadruped animals. The use of a full-elbow leg structure can provide a larger movement space for the leg. Through research and calculation of the movement space, when the ratio of the length of the thigh 11 to the length of the calf 12 is 1:1, the bionic leg has the largest movement space. Most quadruped mammals have leg lengths that account for about 3 / 5 of their total body height. Considering that the body height of the wheel-legged vehicle is 1250 mm, in this paper, the sizes of the thigh and calf of the wheel-legged composite configuration vehicle are designed as L1 = L2 = 750 mm. The hydraulic drive system 2 uses a three-stage hydraulic system. After considering the design requirements and the proportional relationship of the installation positions, the installation positions are located between the thigh 11 and the chassis, and between the thigh 11 and the calf 12. The specific installation positions are as follows: In the hydraulic drive system 2 between the thigh 11 and the chassis, the large end 21 of the hydraulic cylinder is connected 450 mm backward from the fixed position with the thigh 11, and the small end 23 of the hydraulic cylinder is connected 250 mm downward from the fixed position with the thigh 11. In the hydraulic drive system 2 between the thigh 11 and the calf 12, the large end 21 of the hydraulic cylinder is connected 350 mm downward from the fixed position with the thigh 11, and the small end 23 of the hydraulic cylinder is connected 450 mm downward from the calf 12. The above middle hydraulic column 22 connects the large end 21 and the small end 23 of the hydraulic cylinder. To maintain consistency, the hydraulic cylinders between the thigh and the calf and between the thigh and the chassis use the same size and range of hydraulic cylinders. The shortest range of the hydraulic cylinder is 225 mm, and the maximum range is 625 mm. The range of a single-stage hydraulic cylinder is 0 - 200 mm. The non-pneumatic tire adopts the form of a flexible spoke unit. The non-pneumatic tire includes a flexible spoke support and a tread. The water lily-type flexible spoke supports form a non-pneumatic tire through rotational array, with a total of 20 groups. The tread is adhesively fixed to the hub in cooperation with the support, and is fitted with the hole section at the lower end of the calf 12 through the shaft end of the hub.

[0021] As Figure 3 shown, when the wheel-legged vehicle encounters an obstacle that cannot be passed in the wheeled mode, it is converted to the legged mode by the extension of the hydraulic drive system 2 in the wheeled mode. Then, the lifting and lowering actions of the bionic leg 1 are realized through the contraction and extension of the hydraulic drive system 2, and flexible and stable passage on unstructured terrain is achieved by matching a reasonable gait plan.

[0022] The described embodiments are the preferred embodiments of the present invention, but the present invention is not limited to the embodiments. Without departing from the implementation content of the present invention, any obvious improvements, substitutions, or variations that can be made by those skilled in the art belong to the protection scope of the present invention.

Claims

1. A wheeled vehicle, characterized in that: The invention comprises a bionic leg (1), a hydraulic drive system (2), a non-pneumatic tire (3), and an anti-roll frame (4), wherein the bionic leg (1) is composed of a thigh (11) and a calf (12); the positioning shaft at the lower end of the thigh (11) is connected to the positioning hole at the upper end of the calf (12); the length and proportion of the bionic leg are designed according to the proportion and movement space of the legs of most quadrupedal mammals; the hydraulic drive system (2) is a three-level hydraulic system; the hydraulic drive system (2) is installed on the positioning shaft between the thigh and the calf and the positioning shaft between the thigh and the chassis; the non-pneumatic tire (3) adopts a flexible spoke unit form, the non-pneumatic tire (3) comprises a support body (31) and a tread crown (32), and the non-pneumatic tire (3) is installed on one side of the lower end of the calf (12) through a wheel hub; the tread crown (32) is bonded to the support body (31); and the anti-roll frame (4) is of elliptical design.

2. A wheeled vehicle according to claim 1, characterized in that: The bionic leg (1) adopts a full elbow-type leg design scheme, and in the bionic leg (1), the thigh (11) and the calf (12) are made of carbon steel material.

3. A wheeled vehicle according to claim 1, characterized in that: The hydraulic drive system (2) is made of carbon steel. The hydraulic drive system is fully contracted into a wheel mode and fully extended into a foot mode. The two hydraulic drive systems work together to achieve spatial movement of the legs.

4. A wheeled vehicle according to claim 1, characterized in that: The non-pneumatic tire (3) is made of high modulus polyurethane material.

5. A wheeled vehicle according to claim 1, characterized in that: The anti-roll frame (4) is made of high-strength low-alloy steel, and the supporting part is cylindrical.

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