An eight-legged bionic spider robot

Abstract

A highly stable and responsive eight-legged robot, inspired by a spider, closely replicates the functionality of a spider's legs. Spider legs are driven by the antagonistic effect of lymph pressure and muscle force. To mimic the effects of lymph within a spider's legs, joint motion is achieved through push rods. The spider legs are designed based on fixed-size push rods, and hinges connect the segments, enabling stable movement and gentle stress response while meeting the target motion. Subsequently, using the spider's bionic legs as the motion and drive units, the robot's single legs and overall structure were designed to better align with spider motion.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and in particular relates to an eight-legged bionic spider robot. Background Art

[0002] In the field of biomimetic robotics, multi-legged robots are a key branch of bionics. Existing biomimetic machines already mimic common multi-legged creatures, such as robotic dogs and robotic octopuses, exhibit superior maneuverability and flexibility. Compared to wheeled and tracked robots of the same size, multi-legged robots offer advantages in navigating rough terrain, and hold great promise for applications in disaster relief and other areas where traditional robots struggle. However, a review of relevant literature and analysis of existing biomimetic multi-legged robots revealed that current biomimetic mechanisms are not well-designed, making them impractical for practical application. Furthermore, most are small, suitable only for home or laboratory use, and significant gaps remain in research regarding their adaptability to complex and real-world road conditions. This results in significant design differences between biomimetic multi-legged robots and biological counterparts, putting them far from practical application. In recent years, natural disasters have become frequent, with heavy rainfall causing landslides and trapped people, among other issues plaguing various regions. If robots equipped with life detectors could be deployed to enter dangerous areas ahead of rescuers to detect trapped people and then decide whether to send a rescue team in, safety would be greatly improved. Therefore, it is essential to design a multi-legged robot that can adapt to real-world environments and complex road conditions and replace humans in uneven urban areas and in the wild. Summary of the Invention

[0003] The purpose of the present invention is to provide an eight-legged bionic spider robot, which uses spider bionic walking legs as movement and drive units, and designs the eight-legged robot's single legs and overall structure that are more in line with spider movement.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] An octapod bionic spider robot comprises a trunk portion (1) and leg and foot portions (2), characterized in that an upper plate (1-1-1) of the trunk portion (1) is connected to a lower plate (1-1-5) via an upper support column (1-1-2), the lower plate (1-1-5) is connected to a middle plate (1-1-3) via a lower support column (1-1-4), a lead screw motion module (1-2) is connected between the upper plate (1-1-1) and the middle plate (1-1-3), and flange bearings (1-1-6) are fixed to four corners of the upper plate (1-1-1) and the lower plate (1-1-5); the leg and foot portions (2) are mounted via the flange bearings (1-1-6);

[0006] The upper rod bolt connector (2-2) of the leg foot part (2) is connected to the upper outer hexagonal half-thread bolt (2-1), and the lower rod bolt connector (2-6) is connected to the lower outer hexagonal half-thread bolt (2-7). A vertical rod (2-5) is provided between the upper rod bolt connector (2-2) and the lower rod bolt connector (2-6). The upper outer hexagonal half-thread bolt (2-1) and the lower rod bolt connector (2-6) are connected between the upper and lower sets of flange bearings (1-1-6). The vertical rod (2-5) is connected to the aluminum column connector (2-3) through a hinge (2-4); the vertical rod (2-5) is connected to the upper leg rod (2-9) through a hinge (2-8). The upper leg rod ( 2-9) is sequentially connected to the hinge (2-19), the middle leg rod (2-18), the connecting rod (2-17), the hinge (2-16), and the lower leg rod (2-15); the vertical rod (2-5) is sequentially connected to the upper electric push rod (2-20), the lower additional rod (2-11), the lower electric push rod (2-12), and the extension rod (2-13) through the upper additional rod (2-21); the extension rod (2-13) is connected to the lower leg rod (2-15) through the lower side rod (2-14); the lower additional rod (2-11) is connected to the upper side rod (2-10), and the upper side rod (2-10) is connected to the hinge (2-16) through the connecting rod (2-17);

[0007] The aluminum column connector (2-3) is connected to the spherical hinge (1-2-1) of the screw motion module (1-2). The spherical hinge (1-2-1) is connected to the slider (1-2-3) through the right-angle connector (1-2-2). The slider (1-2-3) is connected to the slide rail (1-2-4) to form a sliding structure. A sliding structure is connected to each end of the transmission plate (1-2-5). The transmission plate (1-2-5) is connected to the height compensation block (1-2-7). The height compensation block (1-2-7) is driven by the screw (1-2-6).

[0008] The leg and foot parts (2) are provided in 8 groups, which are evenly distributed on both sides of the trunk part (1).

[0009] The beneficial effects of the present invention are:

[0010] 1) A lead screw mechanism drives the sinusoidal motion of the spider's legs to achieve horizontal swing, reducing the size and complexity of the mechanism, lowering the degree of freedom, and easing control difficulty. 2) A connecting rod mechanism is used to link the tibia and tarsus of the legs, preserving the number of joints while reducing the degree of freedom of the legs, eliminating actuators such as push rods, and simplifying control. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the present invention.

[0012] Figure 2 It is a schematic structural diagram of the leg and foot parts of the present invention.

[0013] Figure 3 It is a schematic structural diagram of the trunk part of the present invention.

[0014] Figure 4 It is a schematic diagram of the structure of the screw motion module of the present invention.

[0015] Among them, 1 trunk part, 2 leg part, 2-1 upper hexagon half-thread bolt, 2-2 upper rod bolt connector, 2-3 aluminum column connector, 2-4 hinge, 2-5 vertical rod, 2-6 lower rod bolt connector, 2-7 lower hexagon half-thread bolt, 2-8 hinge, 2-9 upper leg rod, 2-10 upper side rod, 2-11 lower additional rod, 2-12 lower electric push rod, 2-13 extension rod, 2-14 lower side rod, 2-15 lower leg rod, 2-16 hinge, 2-17 connecting rod, 2-18 middle leg rod, 2-19 hinge, 2-20 upper electric push rod, 2-21 upper additional rod, 1-2-1 spherical hinge, 1-2-2 right-angle connector, 1-2-3 slider, 1-2-4 slide rail, 1-2-5 Transmission plate, 1-2-6 lead screw, 1-2-7 height compensation block. Implementation Method

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Inspired by spiders, the gait and body structure of spiders are analyzed. This invention is an eight-legged spider, focusing on imitating the walking posture of eight-legged spiders. Eight-legged spiders have clear movement patterns and movement cycles when walking. Looking down at the insect, the eight legs are divided into two groups. The left one, right two, left three, and right four are group A legs, and the right one, left two, right three, and left four are group B legs. The two groups of legs swing alternately, such as Figure 1 As shown, the legs in the same group swing in the same direction, while the legs in different groups swing in opposite directions. Connecting the legs with the same motion pattern forms a triangle, hence the name triangular gait. The main mechanisms of this robot include a lead screw slide, a sinusoidal mechanism, a push rod mechanism, and a connecting rod mechanism. These mechanisms work together to propel the bionic spider forward, backward, and turn. The main sub-movements of the robot include leg lift and stepping. Leg lift involves raising and lowering the spider's legs, driven by an electric push rod. Stepping is achieved by a stepper motor-driven lead screw slide, which swings the spider's legs back and forth. A Raspberry Pi 4B is used as the control center, with an external 12V power supply powering the push rod and lead screw slide to ensure stable operation.

[0018] like Figure 2As shown in Figure 3, the body frame is composed of three plates: upper, middle, and lower. The lower and upper plates are equipped with bearing seats to limit the axial and radial rotation of the legs. The middle and upper plates are separated by a large distance, and the main drive components are installed between these two plates. A screw slide is installed to drive the swing of the legs to achieve stepping motion. This design uses a screw slide to drive the leg swinging motion to achieve reciprocating swinging motion of the legs. At the same time, in order to ensure that the swinging pattern of the legs in the same group is the same and meet the movement requirements of the triangular gait, each screw slide connects two legs in the same group, so that the eight legs are driven by a total of four screws. The four screw slides are placed on the middle and upper plates of the fuselage, greatly improving the compactness, stability, and practicality of the machine.

[0019] To enhance the bionic spider's mobility and practicality, the legs are designed to mimic the spider's three-segment structure, tailored to the specific situations encountered in different road conditions. From closest to the body, they are the femur (①), tibia (②), and tarsus (③). For ease of control, push-rod mechanisms connect and control multiple joints. Furthermore, to reduce the number of active components, this design employs a connecting rod mechanism to bind the motion of the tibia and tarsus.

[0020] Motion Design: When the push rods extend and retract, they control the legs' upward and downward movement. This, combined with the movement of the lead screw slide, enables a "triangle" gait that mimics a spider's forward movement. During straight-line movement, the travel of all four lead screws is identical, and the left and right legs travel the same distance. During turns, however, the lead screws on the left and right sides have different travel distances, causing the legs to move at different distances, allowing the entire machine to turn. To achieve these various movements, each leg's basic motion cycle has two phases: 1) Actuation Phase: The legs support the body on the ground and slide backward, moving it forward. 2) Return Phase: The push rods lift the legs, while the lead screws simultaneously drive the legs forward to a new starting point in the actuation phase after the body's forward movement. Straight movement: The bionic spider walks forward using a "triangle" motion. Turning: For example, for a left turn, the lead screw travel on the left side of the machine decreases, reducing the swing distance of the four legs in a single motion cycle. The lead screw travel on the right side remains unchanged. The swing stroke of the corresponding right leg in a single movement cycle remains unchanged, that is, after a movement cycle, the distance traveled by the left side is less than that of the right side, thereby realizing the left turn of the body, and the same applies to the right turn.

[0021] Control Design: The entire mechanical movement is controlled by a Raspberry Pi. The motion patterns of various movements are shown in Table 1.

[0022] Table 1 Action rules

[0023]

[0024] Leg lifting mechanism

[0025] The leg-lifting mechanism has two degrees of freedom, constrained by two push rods mounted on the legs. Push rod 1 is fixed at one end to the waist and at the leg joint (①). Its telescopic motion allows the leg joint to rotate about the waist. Push rod 2 is fixed at one end to the leg joint (①) and at the other end to the tibia (②). Its telescopic motion allows the tibia to rotate about the leg joint. The rotation of the tibia (②) and tarsus (③) is controlled by a connecting rod, which is also determined by push rod 2. Both ends of the push rod are hinged. The connecting rod and the leg frame form a four-bar mechanism. The two push rods are actuated to rotate each leg frame about its hinge joint, achieving up and down swinging, lifting and lowering the leg.

[0026] Maibu Organization

[0027] The swing of the legs is driven by four screw slides on the fuselage. Since each screw controls two legs and the structure is relatively compact, the four screws are installed on the middle plate and the upper plate respectively, in a central symmetrical layout, such as Figure 2 As shown in the figure, the upper plate is equipped with two lead screws that control group A legs, and the middle plate is equipped with two lead screws that control group B legs. When the spider moves, the two lead screws on the upper plate move in exactly the same direction, exactly opposite to the two lead screws on the middle plate. This allows group B legs to retract while group A legs step forward. When group B legs are fully retracted, the lead screws on the upper and middle plates reverse their movement directions, causing group B legs to step forward and group A legs to retract. As the lead screws move back and forth, the spider's legs swing back and forth. The lead screws and legs are connected using a sinusoidal mechanism. The lead screws first drive two parallel guide rails for linear movement. These guide rails are then equipped with spherical hinges that convert the linear motion of the lead screws into rotational motion of the legs.

[0028] Application Prospects

[0029] Based on an analysis of the characteristics of various bionic walking leg products on the market, our robot can be equipped with various payloads, such as life detectors, mechanical claws, and radar. It can play a unique role in firefighting, disaster relief, and resource exploration. The addition of these additional devices enhances the device's functionality and provides high practical value, promising broad application prospects once it is implemented as a practical product.

Claims

1. An octapod bionic spider robot, comprising a trunk portion (1) and leg and foot portions (2), characterized in that: The upper plate (1-1-1) of the trunk portion (1) is connected to the lower plate (1-1-5) via an upper support column (1-1-2), the lower plate (1-1-5) is connected to the middle plate (1-1-3) via a lower support column (1-1-4), a screw motion module (1-2) is connected between the upper plate (1-1-1) and the middle plate (1-1-3), and flange bearings (1-1-6) are fixed at the four corners of the upper plate (1-1-1) and the lower plate (1-1-5); the leg portion (2) is installed via the flange bearings (1-1-6); The upper rod bolt connector (2-2) of the leg foot part (2) is connected to the upper outer hexagonal half-thread bolt (2-1), the lower rod bolt connector (2-6) is connected to the lower outer hexagonal half-thread bolt (2-7), a vertical rod (2-5) is provided between the upper rod bolt connector (2-2) and the lower rod bolt connector (2-6), the upper outer hexagonal half-thread bolt (2-1) and the lower rod bolt connector (2-6) are connected between the upper and lower sets of flange bearings (1-1-6), the vertical rod (2-5) is connected to the aluminum column connector (2-3) through a first hinge (2-4); the vertical rod (2-5) is connected to the upper leg rod (2-9) through a second hinge (2-8). ), the upper leg rod (2-9) is sequentially connected to the fourth hinge (2-19), the middle leg rod (2-18), the third hinge (2-16), and the lower leg rod (2-15); the vertical rod (2-5) is sequentially connected to the upper electric push rod (2-20), the lower additional rod (2-11), the lower electric push rod (2-12), and the extension rod (2-13) through the upper additional rod (2-21); the extension rod (2-13) is connected to the lower leg rod (2-15) through the lower side rod (2-14); the lower additional rod (2-11) is connected to the upper side rod (2-10), and the upper side rod (2-10) is connected to the fifth hinge through the connecting rod (2-17); The aluminum column connector (2-3) is connected to the spherical hinge (1-2-1) of the screw motion module (1-2). The spherical hinge (1-2-1) is connected to the slider (1-2-3) through the right-angle connector (1-2-2). The slider (1-2-3) is connected to the slide rail (1-2-4) to form a sliding structure. A sliding structure is connected to each end of the transmission plate (1-2-5). The transmission plate (1-2-5) is connected to the height compensation block (1-2-7). The height compensation block (1-2-7) is driven by the screw (1-2-6).

2. The eight-legged bionic spider robot according to claim 1, characterized in that: The leg and foot parts (2) are provided in 8 groups, which are evenly distributed on both sides of the trunk part (1).

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