A multimodal pneumatic microrobot based on variable stiffness control

Abstract

This invention relates to a multimodal pneumatic microrobot based on variable stiffness control, comprising a body with first and second rear legs on both sides, and first and second front legs internally. The coefficient of friction for forward movement of the first and second front legs is greater than that for reverse movement; the coefficient of friction for forward movement of the second front legs and the first rear legs is less than that for reverse movement. The body also includes: symmetrically arranged first and second joints, respectively close to the first and second front legs; a first electrode and a second electrode with opposite energizing states; a first airbag mounted on the upper end of the first joint, which achieves reverse movement through cyclic expansion and contraction; and a second airbag mounted on the upper end of the second joint, which achieves forward movement through cyclic expansion and contraction. This invention only requires inflating or deflating the first or second airbag to achieve forward and reverse movement of the robot, reducing air passages and simplifying the structure.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a multimodal pneumatic microrobot based on variable stiffness control. Background Technology

[0002] To achieve multimodal motion and directional control, pneumatic robots often require multiple air channels or additional logic switching elements such as pneumatic valves, which poses challenges to robot design and fabrication. This is particularly true for pneumatic walking robots, which not only have complex structures affecting load capacity but also struggle to reduce size and achieve miniaturization. Summary of the Invention

[0003] To address the technical problems in the background art, this invention discloses a multimodal pneumatic microrobot based on variable stiffness control.

[0004] This invention provides a multimodal pneumatic microrobot based on variable stiffness control, including a body with a first rear foot and a second rear foot on its two sides, and a first front foot on the same side as the first rear foot and a second front foot on the same side as the second rear foot installed inside the body;

[0005] The movement of the fuselage towards the second rear foot is defined as a positive movement.

[0006] The coefficient of friction of the first front foot and the second rear foot moving in the forward direction is greater than the coefficient of friction of moving in the reverse direction.

[0007] The coefficient of friction for the second front foot and the first rear foot moving in the forward direction is less than the coefficient of friction for moving in the reverse direction.

[0008] The machine body is also equipped with:

[0009] The first and second joints are symmetrically arranged, and are close to the first and second forelegs, respectively.

[0010] The first electrode and the second electrode are energized in opposite states and are used to heat the first joint and the second joint respectively to soften them.

[0011] The first airbag is installed at the upper end of the first joint. Through its cyclic expansion and contraction, it drives the first joint to arch or return to its original position, thereby achieving reverse movement.

[0012] The second airbag, installed at the upper end of the second joint, drives the second joint to arch or return to its original position through its cyclic expansion and contraction, thus achieving forward movement.

[0013] When the robot needs to move forward, the second electrode is first energized to soften the second joint. Then, compressed air is filled into the second airbag, causing it to expand. The second joint arches upward, and the second front foot applies pressure to the ground. Since the stiffness of the first joint remains unchanged, the robot moves upward using the second front foot and the first rear foot as fulcrums during the arching of the second joint, with the first front foot and the second rear foot suspended in the air. During the arching of the second joint, the second front foot tends to move in the opposite direction, while the first rear foot tends to move forward. The coefficient of friction of the second front foot is greater than that of the first rear foot, so the second front foot remains stationary, and the first rear foot moves forward a certain distance. Subsequently, the second airbag is depressurized, the second joint returns to its original position, the second front foot tends to move forward, and the first rear foot tends to move in the opposite direction. The coefficient of friction of the second front foot is less than that of the second rear foot, so the first rear foot remains stationary, and the second front foot moves forward a certain distance.

[0014] When the robot needs to move in the opposite direction, simply energize the first electrode.

[0015] This invention only requires inflating or deflating the first or second airbag, and achieves motion function through local stiffness control, enabling the robot to move in both directions. This reduces the number of air passages, simplifies the structure, does not affect the load, and facilitates size reduction.

[0016] To further reduce the number of air passages, the design is as follows: the fuselage is provided with an air slot, the two ends of which are connected to the first airbag and the second airbag respectively; an air nozzle is installed on the air slot.

[0017] To simplify the manufacturing process and reduce costs, the design further involves 3D printing the fuselage, first rear leg, second rear leg, first joint, and second joint into a single unit, using thermoplastic PLA as the material.

[0018] If the joints are too thick, their deformation range is small, and the robot's walking speed is also slow. Based on this, a further design is to provide through grooves on both the first and second joints.

[0019] To achieve different coefficients of friction for forward and reverse movement of the front and rear feet, inclined protrusions are usually set on the bottom of the front and rear feet. This makes the structure complex and increases the manufacturing cost. Moreover, when the front and rear feet wear out, the entire machine body needs to be replaced, further increasing the cost. Based on this, a further improvement is made as follows: the first front foot is equipped with a first front foot friction palm, the second front foot is equipped with a second front foot friction palm, the first rear foot is equipped with a first rear foot friction palm, and the second rear foot is equipped with a second rear foot friction palm. The first front foot friction palm, the second front foot friction palm, the first rear foot friction palm, and the second rear foot friction palm are made of cloth, and the protrusions on the cloth are inclined to one side. Attached Figure Description

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] Figure 1 is a schematic structural diagram of the present invention;

[0022] Figure 2 is a top view of the present invention;

[0023] Figure 3 is Figure 2 a cross-sectional view taken along A-A in

[0024] Figure 4 is a schematic structural diagram of the fuselage;

[0025] Figure 5 is a bottom view of the present invention;

[0026] Figure 6 is a structural diagram of the friction palm;

[0027] In the figure: 1, fuselage; 2, first rear foot; 3, second rear foot; 4, first front foot; 5, second front foot; 6, first joint; 7, second joint; 8, first electrode; 9, second electrode; 10, first airbag; 11, second airbag; 12, air groove; 13, air nozzle; 14, groove; 15, first front foot friction palm; 16, second front foot friction palm; 17, first rear foot friction palm; 18, second rear foot friction palm. Specific embodiments

[0028] The present invention will now be described in further detail in conjunction with the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0029] Embodiment 1:

[0030] As Figure 1-3 shown, the present invention is a multi-modal pneumatic micro-robot based on variable stiffness control, including a rectangular fuselage 1, and its two sides are respectively provided with a first rear foot 2 and a second rear foot 3. The first rear foot 2 and the second rear foot 3 are symmetric, and rectangular holes are opened inside them, making them in the shape of a "hui" character. The fuselage 1 is also equipped with symmetrically arranged first front feet 4 and second front feet 5, and the contact parts with the ground are located inside the rectangular holes.

[0031] Symmetrically arranged first joints 6 and second joints 7 are connected inside the rectangular holes. The first joints 6 and the second joints 7 are perpendicular to the moving direction of the robot. The first joint 6 is located inside the first front foot 4, and a first airbag 10 is installed at the upper end. The first airbag 10 is connected to the first front foot 4 through a partition; the second joint 7 is located inside the second front foot 5, and a second airbag 11 is installed at the upper end. The second airbag 11 is connected to the second front foot 5 through a partition. The first airbag 10 and the second airbag 11 are symmetrically arranged.

[0032] The body 1 is provided with an air groove 12, the two ends of which are connected to the first airbag 10 and the second airbag 11 respectively. An air nozzle 13 is installed on the air groove 12 for inflating or deflating the first airbag 10 and the second airbag 11.

[0033] The first front foot 4 is equipped with a first front foot friction pad 15, the second front foot 5 is equipped with a first front foot friction pad 16, the first rear foot 2 is equipped with a first rear foot friction pad 17, and the second rear foot 3 is equipped with a second rear foot friction pad 18; the first front foot friction pad 15, the first front foot friction pad 16, the first rear foot friction pad 17, and the second rear foot friction pad 18 are in contact with the ground and are made of polyester woven fabric, such as... Figure 6 As shown, the protrusions on the fabric are tilted to one side, so that the coefficient of friction of the first front foot 4 and the second rear foot 3 moving in the forward direction is greater than the coefficient of friction of moving in the reverse direction; the coefficient of friction of the second front foot 5 and the first rear foot 2 moving in the forward direction is less than the coefficient of friction of moving in the reverse direction.

[0034] like Figure 5 As shown, a first electrode 8 and a second electrode 9, both graphene films, are mounted on the bottom of the robot body 1, and are located directly below the first joint 6 and the second joint 7, respectively. The positive electrodes of the first electrode 8 and the second electrode 9 are separated, while their negative electrodes are connected as a whole, and their shapes are formed by laser cutting. When the first electrode 8 and the second electrode 9 are energized, they generate heat, thereby heating and softening the first joint 6 or the second joint 7. When the robot walks, the energizing states of the first electrode 8 and the second electrode 9 are reversed.

[0035] like Figure 4 As shown, the fuselage 1, first rear leg 2, second rear leg 3, first joint 6, and second joint 7 are integrally formed by 3D printing, and the material is thermoplastic PLA. This simplifies the manufacturing process, reduces costs, and thermoplastic PLA softens easily when heated.

[0036] The movement of the robot body 1 towards the second rear foot 3 is considered forward movement. When the robot needs to move forward, the second electrode 9 is first energized to soften the second joint 7; then compressed air is injected into the first airbag 10 and the second airbag 11 to inflate them, causing the second joint 7 to arch upwards and press the second front foot 5 against the ground. Since the first joint 6 is not heated and its hardness does not change, the expansion of the first airbag 10 will not cause the first joint 6 to deform. During the arching of the second joint 7, the robot will move upwards using the second front foot 5 and the first rear foot 2 as fulcrums, while the first front foot 4 and the second rear foot 3 are suspended in the air; during the arching of the second joint 7, the second front foot 5 has a tendency to move in the opposite direction, while the first rear foot 2 has a tendency to move forward. The coefficient of friction of the second front foot 5 is greater than that of the first rear foot 2, so the second front foot 5 remains stationary, while the first rear foot 2 moves forward a certain distance.

[0037] Subsequently, the second airbag 11 depressurizes, the second joint 7 resets, the second front foot 5 tends to move forward, and the first rear foot 2 tends to move backward. The friction coefficient of the second front foot 5 is less than that of the second rear foot 3, so the first rear foot 2 remains stationary, and the second front foot 5 moves forward a certain distance.

[0038] Thus, by cyclically expanding and contracting the second airbag 11, the second joint 7 is driven to arch or return to its original position, achieving forward movement.

[0039] When the robot needs to move in the opposite direction, the first electrode 8 is energized, and the first airbag 11 expands and contracts cyclically, driving the first joint 6 to arch or reset, thus achieving reverse movement.

[0040] The present invention only requires inflating or deflating the first airbag 10 or the second airbag 11, and realizes the motion function through local stiffness control, enabling the robot to move in the forward and reverse directions. This reduces the number of air passages, simplifies the structure, does not affect the load, and facilitates the reduction of volume.

[0041] Example 2:

[0042] Compared to Embodiment 1, the difference is that both the first joint 6 and the second joint 7 are provided with through grooves 14. The grooves 14 reduce the thickness of the joints, thereby increasing the deformation range of the joints and improving the robot's movement speed. Moreover, the grooves 14 also serve as joint deformation guides, causing the joints to deform along the direction of the grooves 14, resulting in more stable and regular deformation without twisting.

[0043] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A multimodal pneumatic microrobot based on variable stiffness control, characterized in that: Includes a fuselage (1), with a first rear foot (2) and a second rear foot (3) on its two sides respectively, and a first front foot (4) on the same side as the first rear foot (2) and a second front foot (5) on the same side as the second rear foot (3) installed inside it; The movement of the fuselage (1) toward the second rear foot (3) is defined as a positive movement; The coefficient of friction of the first front foot (4) and the second rear foot (3) moving in the forward direction is greater than the coefficient of friction of moving in the reverse direction; The coefficient of friction of the second front foot (5) and the first rear foot (2) moving in the forward direction is less than the coefficient of friction of moving in the reverse direction; The fuselage (1) is also equipped with: The first joint (6) and the second joint (7) are symmetrically arranged and are close to the first front foot (4) and the second front foot (5), respectively. The first electrode (8) and the second electrode (9) are in opposite energizing states and are used to heat the first joint (6) and the second joint (7) respectively, so as to soften them. The first airbag (10) is installed on the upper end of the first joint (6). Through its cyclic expansion and contraction, it drives the first joint (6) to arch or reset, thereby achieving reverse movement. The second airbag (11) is installed on the upper end of the second joint (7). Through its cyclic expansion and contraction, it drives the second joint (7) to arch or reset, thereby achieving forward movement.

2. The multimodal pneumatic microrobot based on variable stiffness control according to claim 1, characterized in that: The fuselage (1) is provided with an air groove (12), the two ends of which are connected to the first airbag (10) and the second airbag (11) respectively; an air nozzle (13) is installed on the air groove (12).

3. The multimodal pneumatic microrobot based on variable stiffness control according to claim 1, characterized in that: The fuselage (1), first rear leg (2), second rear leg (3), first joint (6) and second joint (7) are integrally formed by 3D printing, and the material is thermoplastic PLA.

4. A multimodal pneumatic microrobot based on variable stiffness control according to claim 1, characterized in that: Both the first joint (6) and the second joint (7) are provided with through grooves (14).

5. A multimodal pneumatic microrobot based on variable stiffness control according to claim 3, characterized in that: The first front foot (4) is provided with a first front foot friction palm (15), the second front foot (5) is provided with a second front foot friction palm (16), the first rear foot (2) is provided with a first rear foot friction palm (17), and the second rear foot (3) is provided with a second rear foot friction palm (18). The first front foot friction palm (15), the second front foot friction palm (16), the first rear foot friction palm (17), and the second rear foot friction palm (18) are made of fabric, and the protrusions on the fabric are tilted to one side.

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