A dual-source synergistic driving multi-gait quadruped robot with anisotropic stiffness legs

Abstract

This invention belongs to the field of soft robot technology and provides a dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs. This invention achieves bending motion of the leg structure through differential drive, combined with the rotational degree of freedom of the hip joint provided by the hollow motor, enabling the robot to have both compliant deformation ability and stable support ability, taking into account good environmental adaptability and sufficient load capacity, effectively solving the problems of poor load capacity and weak anti-interference ability of traditional flexible legs. At the same time, this invention is equipped with multiple gait movement modes, which can switch between single-leg swinging low-speed walking or diagonal fast walking according to the actual application scenario, and can also flexibly realize the adjustment of turning and movement direction. Compared with the traditional simple periodic inflation and deflation control method, it has a wider range of application scenarios.

Description

Technical Field

[0001] This invention belongs to the field of soft robot technology, specifically relating to a dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs. Background Technology

[0002] With the mature development of robots, their application scenarios have gradually expanded to multiple directions such as complex terrain, narrow spaces, and human-computer interaction. Traditional rigid-legged robots usually rely on motors to provide power, and various transmission structures form their mechanical shell. They have high structural rigidity and control precision and are widely used in traditional industrial fields. However, the mechanism itself lacks compliance and has poor environmental adaptability. In confined space environments, they are difficult to play a significant role and exhibit motion instability.

[0003] To address the aforementioned issues, soft robots have become an important research direction in the field of robotics. Among them, pneumatic soft quadruped robots possess the characteristics of material flexibility and large deformation. Their movement is controlled by manipulating the inflation and deflation of pneumatic actuators, offering advantages such as compliant structure, small size, high interactive safety, and strong environmental adaptability. Therefore, soft quadruped robots show promising application prospects in scenarios such as disaster search and rescue, pipeline inspection, and human-robot interaction.

[0004] However, current pneumatic soft quadruped robots still have certain shortcomings in terms of structural design, drive methods, and motion stability. On the one hand, although the leg structure of flexible robots has good deformability, its load-bearing capacity is poor and its anti-interference ability is weak, limiting its application scenarios. On the other hand, the gait control of existing pneumatic quadruped robots mostly uses simple periodic inflation and deflation or ordinary diagonal alternation, which has limited applicability. Therefore, it is urgent to design a pneumatic soft quadruped robot structure that can balance compliant bending and stable support, and further propose a differential pneumatic gait control method that matches this structure to overcome the above-mentioned technical challenges. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs, thereby solving the problems in the prior art. The technical solution adopted by this invention is as follows: A dual-source cooperative-driven multi-gait quadruped robot with non-isotropic stiffness legs, comprising: body; Four non-isotropic stiffness leg structures are provided, and each of the four non-isotropic stiffness leg structures is connected to the fuselage via a corresponding hollow motor. The hollow motor is used to control the swing direction of the leg structure. The non-isotropic stiffness leg structure includes multiple vertebrae connected end to end. Adjacent vertebrae are connected by a bellows. The bellows is connected to an air supply system. The air supply system is used to control the inflation and deflation of the bellows. The bending motion of the non-isotropic stiffness leg structure is realized through differential drive. The hollow motor and the air supply system work together to enable the soft quadruped robot to achieve a variety of gait movements.

[0006] Furthermore, two adjacent vertebrae are rotatably connected by a pin, which passes through corresponding holes in the adjacent vertebrae and is limited by a retaining spring.

[0007] Furthermore, the joints include whole joints, concave joints, and convex joints; The entire joint has symmetrical through holes inside to accommodate two symmetrically installed bellows; both ends and the middle of the entire joint are provided with arc-shaped grooves, wherein the arc-shaped grooves at both ends are used to provide movement space for the bellows, and the arc-shaped groove in the middle is used to install pipe clamps to fix the bellows. The two ends of the full joint are rotatably connected to the concave joint and the convex joint by pins respectively; both the concave joint and the convex joint are provided with two symmetrical arc-shaped grooves inside, for accommodating the two ends of the two bellows.

[0008] Furthermore, the concave joint is located at the top and is connected to the hollow motor; the concave joint is provided with a corresponding air pipe opening for the air pipe to pass through and connect the air supply system and the two corrugated pipes; The air supply system includes an air pump, and the two corrugated pipes are respectively connected to the air pump. The air pump provides positive and negative air pressure to the two corrugated pipes respectively, thereby causing the two corrugated pipes to extend or shorten to achieve bending movement.

[0009] Furthermore, each of the aforementioned non-isotropic stiffness leg structures includes two degrees of freedom: one is the hip joint rotational degree of freedom achieved by the hollow motor drive, and the other is the hip joint flexion-extension degree of freedom achieved by the bellows differential drive.

[0010] Furthermore, the various gait movements of soft quadruped robots include: The single-leg swinging gait involves four non-isotropic stiffness leg structures bending and swinging in sequence, while the remaining non-isotropic stiffness leg structures support the ground to achieve low-speed walking. Diagonal gait, in which two diagonally distributed isotropic stiffness leg structures bend and swing synchronously, while two other diagonally distributed isotropic stiffness leg structures support the ground, to achieve rapid walking; By adjusting the rotational degrees of freedom of each non-isotropic stiffness leg structure, the soft quadruped robot can achieve on-the-spot turning, turning, or diagonal movement based on a single-leg swinging gait or diagonal gait.

[0011] Furthermore, the vertebrae are provided in multiple ways to adjust the length of the non-isotropic stiffness leg structure.

[0012] Furthermore, the fuselage has a hollow structure.

[0013] The present invention has the following beneficial effects: This invention achieves bending motion of the leg structure through differential drive, combined with the rotational freedom of the hip joint provided by the hollow motor, enabling the robot to possess both compliant deformation capability and stable support capability. It also ensures good environmental adaptability and sufficient load capacity, effectively solving the problems of poor load capacity and weak anti-interference capability of traditional flexible legs. At the same time, this invention is equipped with multiple gait movement modes, which can switch between single-leg swinging low-speed walking or diagonal fast walking according to the actual application scenario. It can also flexibly realize the adjustment of turning and movement direction. Compared with the traditional simple periodic inflation and deflation control method, it has a wider range of application scenarios. Attached Figure Description

[0014] Figure 1 This is a structural diagram of the present invention; Figure 2 This is a schematic diagram of a non-isotropic stiffness leg structure. Figure 3 This is a schematic diagram of the entire joint; Figure 4 This is a schematic diagram of a protruding joint; Figure 5 A schematic diagram of a concave osteophyte; Figure 6 This is a schematic diagram of the fuselage; Figure 7 This is a diagram illustrating turning and walking. Figure 8 This is a schematic diagram of an oblique gait. Figure 9 This is a schematic diagram of translational movement; Figure 10 This is a diagram illustrating low-posture walking. Detailed Implementation

[0015] The following will be based on embodiments of the present invention. Figures 1-10 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0016] like Figure 1A dual-source cooperative-driven multi-gait quadruped robot with non-isotropic stiffness legs, comprising: Body 1, the robot's skeleton; Four non-isotropic stiffness leg structures 3 are connected to the fuselage 1 via corresponding hollow motors 2. The hollow motors 2 are used to control the swing direction of the leg structures. The hollow motors 2 are discrete joints connecting the non-isotropic stiffness leg structures 3 to the fuselage 1, and are used to control the specific direction of the leg structures. The non-isotropic stiffness leg structure 3 includes multiple vertebrae connected end to end. Adjacent vertebrae are connected by a bellows 5. The bellows 5 is connected to an air supply system. The air supply system is used to control the inflation and deflation of the bellows 5. The bending motion of the non-isotropic stiffness leg structure 3 is realized by differential drive. The vertebrae are provided in multiple ways to adjust the length of the non-isotropic stiffness leg structure 3.

[0017] The hollow motor 2 and the air supply system work together to enable the soft quadruped robot to achieve a variety of gait movements.

[0018] Furthermore, two adjacent vertebrae are rotatably connected by a pin 10, which passes through the corresponding hole of the adjacent vertebrae and is limited by a retaining spring 9.

[0019] The non-isotropic stiffness leg structure 3 is mechanically constrained by multiple joints and differentially driven by two sets of bellows 5. The joints are connected by pins 10 with retaining rings 9. The pins 10 connect two adjacent joints through first holes 11 and second holes 18, and the retaining rings 9 limit the pins, thus facilitating joint installation. Two bellows 5 are symmetrically installed between the joints, and movement is achieved through differential drive, i.e., the bellows are inflated and deflated. The bellows 5 are connected to an air supply system. This structure achieves the following: First, it allows for rotational movement around the axis of the pin 10, thus achieving bending of the leg structure; stiffness is relatively low in this direction. Second, in the axial direction of the pin 10, the joints are constrained by the male seat 19, female seat 12, pin 10, and retaining rings 9, thus limiting displacement along the pin 10 direction; stiffness is relatively high in this direction. These two factors combined achieve non-isotropic stiffness performance. The retaining rings 9 provide lateral restraint of components without affecting rotation around the axis.

[0020] like Figures 2-5 The joints include a full joint 7, a concave joint 4, and a convex joint 8, all made of PLC material and fabricated using a 3D printer; The entire joint 7 has symmetrical through holes 13 inside, which are used to accommodate two symmetrically installed bellows 5; both ends and the middle of the entire joint 7 are provided with arc-shaped grooves 20, wherein the arc-shaped grooves 20 at both ends are used to provide movement space for the bellows 5, and the arc-shaped groove 20 in the middle is used to install pipe clamps 6, which are used to axially fix the bellows 5 and limit the position of each section of the bellows 5. The two ends of the full joint 7 are rotatably connected to the concave joint 4 and the convex joint 8 by pins 10 respectively; both the concave joint 4 and the convex joint 8 are provided with two symmetrical arc-shaped grooves 21 inside, for accommodating the two ends of the two corrugated pipes 5.

[0021] The two ends of the full-section segment 7 are respectively provided with protrusions 19 and recessed slots 12 to connect the concave segment 4 and the convex segment 8, maintaining coaxiality in the axial direction. The retaining spring 9 provides installation space through the reserved slot 14. The opposite ends of the concave segment 4 and the convex segment 8 are each provided with a second arc-shaped groove 15 to provide movement space for the bellows 5.

[0022] Furthermore, the concave joint 4 is located at the top and is connected to the hollow motor 2; the concave joint 4 is provided with a corresponding air pipe port 17 for the air pipe to pass through and connect the air supply system and the two bellows 5; the concave joint 4 is connected to the corresponding hollow motor 2 through flange 24 and bolts 22 and bolt holes 16.

[0023] The air supply system includes an air pump, and the two corrugated pipes 5 are respectively connected to the air pump. The air pump provides positive and negative air pressure to the two corrugated pipes 5, thereby causing the two corrugated pipes 5 to extend or shorten to achieve bending movement.

[0024] Each non-isotropic stiffness leg structure 3 has two air pumps connected to corresponding proportional air pressure regulating valves. According to the controller's instructions, the input air pressure of the two air pumps is converted into a single output air pressure, which is connected to the bellows 5 via an air pipe, effectively controlling the movement of the bellows. This invention includes two proportional regulating valves, each controlling two symmetrically installed bellows 5 to ensure they are in the same frequency but out of phase, thereby controlling the robot's movement.

[0025] In this invention, each of the non-isotropic stiffness leg structures 3 includes two degrees of freedom: one is the hip joint rotational degree of freedom achieved by the hollow motor 2, and the other is the hip joint flexion-extension degree of freedom achieved by the differential drive of the bellows 5.

[0026] Let's define the rotation of the left foreleg as LF-R, the flexion of the left foreleg as LF-B, the rotation of the right foreleg as RF-R, the flexion of the right foreleg as RF-B, the rotation of the left hind leg as LH-R, the flexion of the left hind leg as LH-B, the rotation of the right hind leg as RH-R, and the flexion of the right hind leg as RH-B. Negative angles represent leg adduction, and positive angles represent leg external rotation. Additionally, negative angles represent leg flexion backward, and positive angles represent leg flexion forward. In this case, the gait of the soft robot includes the following: In the single-leg swing gait, four non-isotropic stiffness leg structures 3 bend and swing in sequence, while the remaining non-isotropic stiffness leg structures 3 support the ground to achieve low-speed walking. In some embodiments, during the single-leg swing gait, all four legs enter the swing state sequentially in the order of left rear-left front-right rear-right front-repeated, thereby achieving forward movement of the robot. Specifically, LH-B first bends forward, completes the forward swing, and then pushes off the ground backward. LF-B then bends forward and pushes off the ground backward. Subsequently, RH-B bends forward and pushes off the ground backward, and finally RF-B bends forward and pushes off the ground backward. Throughout the entire process, the rotational degrees of freedom remain at their initial values.

[0027] In this gait, only one leg is in the dominant swinging position at any given time, while the other three legs are in the supporting position. It offers high stability, simple control, and is suitable for low-speed walking. Diagonal gait, in which two diagonally distributed isotropic stiffness leg structures 3 bend and swing synchronously, while two other diagonally distributed isotropic stiffness leg structures 3 support the ground, in order to achieve rapid walking; In some embodiments, the four legs are divided into two groups according to a diagonal distribution, entering a swinging state sequentially to achieve more efficient forward movement. Specifically, RF-B and LH-B simultaneously bend forward first, then push off the ground backward, and enter a supporting state upon landing. Subsequently, LF-B and RH-B simultaneously bend forward first, then push off the ground backward, and then enter a supporting state. The entire movement process repeats the above cycle, while maintaining the initial values ​​of rotational degrees of freedom. In this gait, the two groups of diagonal legs alternately undertake the functions of swinging and supporting, resulting in a faster speed and higher operating efficiency compared to a single-leg swinging gait.

[0028] By adjusting the rotational degrees of freedom of each non-isotropic stiffness leg structure 3, the soft quadruped robot can achieve on-the-spot turning, turning, or diagonal movement based on single-leg swinging gait or diagonal gait.

[0029] Turning in place: The robot can turn in place with minimal overall translation. This example uses a right turn as an example; LF-R and RH-R are adjusted to... Inward adjustment, RF-R and LH-R adjusted to With the outstretched legs generating torques in the same direction, and maintaining the initial values, a diagonal gait is adopted, causing each leg to exert a directional tangential force on the ground during contact, thus achieving the task of fuselage rotation. By reversing the directions of the aforementioned rotational degrees of freedom, a left turn can be achieved.

[0030] Turning and walking: The robot achieves turning while maintaining a single-leg swinging gait. This example uses a right turn as an example, with LF-R preset to - LH-R is - To stabilize its position, RF-R was set to - RH-R set to - The left leg provides a torque for right rotation, thus causing the robot to turn right, as shown below. Figure 7 As shown.

[0031] Diagonal gait: The robot can move in any direction without turning, including special lateral movements. This example uses the direction to the right and forward. Taking movement as an example, the preset rotational joints rotate by a uniform 45 degrees, that is, LF-R is - LH-R is - RF-R set to RH-R set to Bending the joint can be achieved by using a single-leg swing gait or a diagonal gait to move forward, such as... Figure 8 As shown.

[0032] In this example, lateral movement is achieved at a special angle. Taking rightward translation as an example, the default LF-R is - LH-R is - RF-R set to RH-R set to With all four legs providing force to the right, lateral movement can be achieved using a single-leg swing gait or a diagonal gait, such as... Figure 9 As shown.

[0033] Low-profile walking: When faced with height limitations, the robot can lower its own height to walk. In this example, a low-profile base bias is preset, and LF-B and RF-B are set to... LH-B and RH-B are set to The front leg leans forward and the hind leg leans backward, forming a prone position. Based on this, the gait described above can be used for movement, enabling movement under height restrictions, such as... Figure 10 As shown.

[0034] In this example, if the height restriction is severe, the front leg base offset can be set to... The hind leg base offset is set to Then, the rotating joints are used alternately to drive the legs for crawling. Specifically, the flexing joints are kept at their initial offset, and LF-R and RH-R move simultaneously from... Become 1 The rotation of the joint causes the leg to move backward, thereby providing a forward force that propels the LF-B from... Transform into RH-B from Transform into This is equivalent to lifting both legs, and then simultaneously raising LF-R and RH-R from 1. Become The other set of diagonal feet repeats this type of movement, enabling crawling.

[0035] In addition, in this invention, the body 1 is a hollow structure. The body 1 has a motor wiring groove 25, and the air pipe wiring passes through the connecting through hole 25 and then connects to the external proportional regulating valve through the housing 27. To facilitate installation, an installation space 26 is reserved for easy installation and wiring, and the body 1 is provided with slots 23 for installing each hollow motor 2.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, alterations, substitutions, or variations made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs, characterized in that, include: fuselage (1); Four non-isotropic stiffness leg structures (3), the four non-isotropic stiffness leg structures (3) are respectively connected to the fuselage (1) through corresponding hollow motors (2), and the hollow motors (2) are used to control the swing direction of the leg structures; The non-isotropic stiffness leg structure (3) includes multiple vertebrae connected end to end. Two adjacent vertebrae are connected by a bellows (5). The bellows (5) is connected to an air supply system. The air supply system is used to control the inflation and deflation of the bellows (5). The bending motion of the non-isotropic stiffness leg structure (3) is realized by differential drive. The hollow motor (2) and the air supply system work together to enable the soft quadruped robot to achieve a variety of gait movements.

2. The dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 1, characterized in that, Two adjacent vertebrae are rotatably connected by a pin (10), which passes through the corresponding hole of the adjacent vertebrae and is limited by a snap ring (9).

3. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 1 or 2, characterized in that, The joints include whole joints (7), concave joints (4), and convex joints (8); The entire joint (7) has symmetrical through holes (13) inside, which are used to accommodate two symmetrically installed bellows (5); the entire joint (7) has arc grooves (20) at both ends and in the middle, wherein the arc grooves (20) at both ends are used to provide movement space for the bellows (5), and the arc groove (20) in the middle is used to install pipe clamps (6) to fix the bellows (5); The two ends of the full bone segment (7) are rotatably connected to the concave bone segment (4) and the convex bone segment (8) by pins (10); the concave bone segment (4) and the convex bone segment (8) are provided with two symmetrical arc-shaped grooves (21) inside, which are used to accommodate the two ends of the two corrugated pipes (5).

4. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 3, characterized in that, The concave section (4) is located at the top and is connected to the hollow motor (2); the concave section (4) is provided with a corresponding air pipe port (17) for the air pipe to pass through and connect the air supply system and the two corrugated pipes (5). The air supply system includes an air pump, and the two corrugated pipes (5) are respectively connected to the air pump. The air pump provides positive and negative air pressure to the two corrugated pipes (5) respectively, thereby causing the two corrugated pipes (5) to lengthen or shorten to achieve bending movement.

5. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 1, characterized in that, Each of the aforementioned non-isotropic stiffness leg structures (3) includes two degrees of freedom: One of them is the degree of freedom of hip joint rotation driven by the hollow motor (2), and the other is the degree of freedom of hip joint flexion and extension driven by the bellows (5).

6. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 1, characterized in that, The various gait movements of soft quadruped robots include: In the single-leg swing gait, four non-isotropic stiffness leg structures (3) bend and swing in sequence, while the remaining non-isotropic stiffness leg structures (3) support the ground to achieve low-speed walking. Diagonal gait, that is, two diagonally distributed isotropic stiffness leg structures (3) bend and swing synchronously, while two other diagonally distributed isotropic stiffness leg structures (3) support the ground to achieve fast walking; By adjusting the rotational degrees of freedom of each non-isotropic stiffness leg structure (3), the soft quadruped robot can achieve on-the-spot turning, turning, or diagonal movement based on single-leg swinging gait or diagonal gait.

7. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 1, characterized in that, The joints are provided in multiple ways to adjust the length of the non-isotropic stiffness leg structure (3).

8. A dual-source cooperative drive multi-gait quadruped robot with non-isotropic stiffness legs according to claim 1, characterized in that, The fuselage (1) is a hollow structure.

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