Flexible mechanical arm based on lattice structure

Abstract

The invention discloses a flexible mechanical arm based on a lattice structure. A driver of the flexible mechanical arm covers three rotational degrees of freedom, two extension degrees of freedom and one grabbing degree of freedom. All driving structures of the mechanical arm are composed of dot matrix structure drivers, and each driver is composed of the same rhombic driving units. According to the flexible mechanical arm, all the driving joints can be of flexible structures, and meanwhile the flexible mechanical arm has the capacity of generating rotation, stretching and grabbing actions. Besides, each driver of the flexible mechanical arm can achieve bidirectional movement, the output rigidity of the drivers can be changed, and therefore the flexibility, adaptability and operation performance of the mechanical arm are effectively improved, and the flexible mechanical arm has wide application prospects in various complex application scenes.

Description

Technical Field

[0001] The present invention belongs to the field of robots, and particularly relates to a flexible robotic arm based on a lattice structure. Background Art

[0002] In the process of industrial production, robotic equipment plays a very important role, among which the most widely used is the industrial robotic arm. Traditional robotic arms are usually based on rigid link structures and are mainly made of metal materials. Such robotic arms have many advantages, such as high positioning accuracy, strong load capacity, fast response speed, etc., so they have been widely used in many fields such as industrial welding, manufacturing, goods assembly and sorting. However, these traditional robotic arms also have some obvious deficiencies. Most traditional robotic arms are large in size, heavy in weight, and relatively high in manufacturing cost, which to a certain extent limits their further development and application scope. Especially in some specific scenarios that require human-robot interaction, due to their rigid structure, traditional robotic arms are very likely to cause harm to the operator when colliding or contacting with the operator, presenting a relatively large safety hazard.

[0003] To overcome these limitations of traditional robotic arms, robotic arms based on flexible materials have emerged. Flexible robotic arms have good compliance, can effectively ensure the stability of the entire system when encountering external disturbances, and will not cause great damage to the surrounding environment or objects when being disturbed. At present, quite a few achievements have been made in the research work on flexible robotic arms. For example, Patent CN 110293581 B proposes a flexible robotic arm based on a corrugated pipe structure. By changing the air pressure in the cavity of the corrugated pipe, the attitude adjustment of the bionic soft robotic arm and the grasping system can be achieved.

[0004] Patent CN 111660286 B proposes a pneumatic artificial muscle fiber and a bionic robotic arm, which can achieve a relatively large movement space and effectively improve the safety of human-robot interaction.

[0005] However, there are still some problems with the above patents: 1. Most flexible robotic arms are based on continuum structures, and the movements between different joints will generate mutual perturbations, which makes it very difficult to perform accurate position calculation and control on them, thereby restricting the end movement space.

[0006] 2. The structure of flexible robotic arms is often relatively complex, which brings many inconveniences to their manufacturing process, increasing the manufacturing difficulty and cost. Summary of the Invention

[0007] To solve the above problems, the present invention discloses a flexible robotic arm based on a lattice structure. To achieve the above object, the technical solution of the present invention is as follows: A flexible robotic arm based on a lattice structure, comprising a mounting base, a base connector, a joint connector, a gripper connector, a rotary actuator I, a rotary actuator II, a rotary actuator III, a linear actuator I, a linear actuator II, and an end gripper; wherein, the mounting base, the base connector, the joint connector, and the gripper connector are rigid structures; while the rotary actuator I, the rotary actuator II, the rotary actuator III, the linear actuator I, the linear actuator II, and the end gripper are flexible structures; each actuator is composed of the same rhombic drive unit.

[0008] The linear actuator I and the linear actuator II are respectively connected to the rotary actuator III on the joint connector from both sides. The other side of the linear actuator I is connected to the rotary actuator II on the base connector. The mounting base is arranged below the base connector. The rotary actuator I is arranged inside the mounting base. The other end of the linear actuator II is connected to the end gripper through the gripper connector.

[0009] Each drive unit includes a support structure, a buckling airbag, and an extension airbag. Specifically, the support structure is a rhombic structure made of a single-layer TPU material, which can ensure that the drive unit always maintains a rhombic shape during movement. The buckling airbag is a folded structure composed of two layers of TPU materials and is connected to the support structure. The extension airbag is a rectangular structure, also composed of two layers of TPU materials, and is arranged at the diagonal position of the support structure. During the processing, first, the two layers of the two airbags need to be processed to form a closed airbag form. Then, the two layers of TPU materials are welded to form a rhombic support structure. Then, the two ends of the buckling airbag are respectively welded to the middle of the support structure. Finally, one side of the extension airbag is welded to the middle of the buckling airbag, and the other side is welded to the support structure, thus forming a drive unit with an antagonistic structure.

[0010] The robotic arm includes three types of lattice structure actuators, namely a rotary actuator connected in a circular shape, a linear actuator connected in a linear shape, and an end gripper connected in a ring shape. The rotary actuator is composed of 6 drive units. Between the three drive units, the initial axis and the output axis of the rotary actuator are respectively set. By controlling the air pressure of the buckling and extension airbags inside the actuator, the rotation angle adjustment of the actuator can be achieved. In addition, the actuator can also achieve variable stiffness output of the rotary actuator by changing the internal air pressure. The linear actuator is composed of 10 drive units, and each drive unit is connected in sequence in the same direction. The linear actuator can change the linear length of the linear actuator and the linear stiffness of the actuator by changing the air pressure values of the internal buckling and extension airbags.

[0011] The mounting base is composed of a circular base, a support plate and a panel. The support plate is arranged parallel to the base above the base through legs. The panel is arranged above the support plate. A rotary support shaft is provided directly below the panel and passes through the support plate. A first rotary drive is placed directly above the circular base. A fixed baffle is provided below the support plate. The rotary support shaft is arranged on one side of the fixed baffle. The rotary support shaft is also connected to the vertical plate on the base connecting piece, so as to realize the output angle control between the mounting base and the base connecting piece.

[0012] The base connecting piece is a circular vertical plate, which provides a rotary shaft and a fixed baffle for the second rotary drive. The second rotary drive is installed on the circular vertical plate. Its initial shaft is connected to the fixed baffle on the base connecting piece, and the output shaft is connected to the first linear drive.

[0013] One side of the first linear drive is connected to the second rotary drive, and the other end is connected to the joint connecting piece. The joint connecting piece is a circular support structure, which provides a rotary shaft for the third rotary drive. The fixed baffle above the joint connecting piece is connected to the first linear drive. The third rotary drive is installed on the joint connecting piece. Its initial shaft is connected to the first linear drive, and the output shaft is connected to the second linear drive, which is used to control the movement angle between the two linear drives.

[0014] One end of the second linear drive is connected to the jaw connecting piece, and the other end is connected to the end jaw through the jaw connecting piece. The end jaw is composed of 4 drive units. Each drive unit is connected end to end in sequence to form an annular structure. By changing the width of the drive unit, the end jaw can realize the grasping function, and is especially suitable for grasping some delicate and irregular objects.

[0015] The beneficial effects of the present invention are as follows: 1. The flexible robotic arm is made of TPU material. The whole is made of pure flexible material, and has many advantages such as small volume, light weight and low cost, and can effectively overcome the deficiencies of traditional robotic arms such as large volume, heavy weight and high cost.

[0016] 2. The flexible robotic arm is based on a lattice structure. The lattice structure driver is composed of multiple drive units. During the driving process, the same airbag cavities of multiple drive units are controlled simultaneously, which has the advantages of simple processing and control. In addition, the lattice structure driver can significantly improve the output force of the driver and reduce the gas required by the driver without affecting the volume and weight, thereby improving the response speed of the flexible driver. 3. A single driver of the lattice structure driver is an antagonistic structure. Two drive airbags can act on the same angle at the same time, and can control the output stiffness while controlling the angle. 4. The rotary drive can simultaneously realize the rotation of the drive and the output of the variable stiffness angle only by changing the air pressure in the internal cavity of the drive. 5. This linear actuator not only functions as a connecting rod, but also provides linear extension and compression functions. At the same time, the actuator can also achieve variable stiffness output of the linear actuator through the internal cavity of the drive unit; 6. The end gripper can achieve flexible and fully wrapped grasping, which is particularly suitable for grasping some delicate and irregular objects, effectively improving the grasping ability and applicability of the robotic arm in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the lattice structure flexible robotic arm of the present invention; Figure 2 is a schematic diagram of the mounting base of the present invention; Figure 3 is a schematic diagram of the base connector of the present invention; Figure 4 is a connection diagram of the mounting base and the base connector according to the present invention; Figure 5 This is a schematic diagram of the connection between the second rotary driver and the first linear driver according to the present invention; Figure 6 Schematic diagram of the initial state of the end clamping jaw of the present invention; Figure 7 Schematic diagram of the gripping state of the end gripper of the present invention; Figure 8 Schematic diagram of the open state of the end clamping jaw of the present invention; Figure 9 Schematic diagram of the initial state of the linear actuator of the present invention; Figure 10 Schematic diagram of the linear actuator of the present invention in a compressed state; Figure 11 1 is a schematic diagram of the linear actuator of the present invention in an extended state; Figure 12 is a schematic diagram of the initial state of the rotary driver according to the present invention; Figure 13 This is a schematic diagram of the rotating actuator of the present invention in a bent state; Figure 14 This is a schematic diagram of the composition of a single driver described in the present invention.

[0018] List of Figure Symbols: 1. Fixed desktop, 2. Rotation driver 1, 3. Installation base, 4. Base connection part, 5. Rotation driver 2, 6. Linear driver 1, 7. Joint connection part, 8. Rotation driver 3, 9. Linear driver 2, 10. Jaw connection part, 11. End jaw, 12. Support structure, 13. Flexion airbag, 14. Extension airbag, 15. Circular base, 16. Support plate, 17. Panel, 18. Fixed baffle, 19. Vertical plate, 20. Fixed baffle, 21. Output shaft. Detailed implementation manner

[0019] The following further clarifies the present invention in conjunction with the accompanying drawings and the detailed implementation manner. It should be understood that the following detailed implementation manner is only used to illustrate the present invention and not to limit the scope of the present invention.

[0020] As shown in the figure, a flexible robotic arm based on a lattice structure according to the present invention has three rotational degrees of freedom, two extension degrees of freedom, and one grasping degree of freedom in its drivers. All drive structures of the robotic arm are composed of lattice structure drivers, and each driver is composed of the same rhombic drive units.

[0021] The lattice structure flexible robotic arm mainly consists of components such as an installation base 3, a base connection part 4, a joint connection part 7, a jaw connection part 10, a rotation driver 1 2, a rotation driver 2 5, a rotation driver 3 8, a linear driver 1 6, a linear driver 2 9, and an end jaw 11. Among them, the installation base 3, the base connection part 4, the joint connection part 7, and the jaw connection part 10 are rigid structures; while the rotation driver 1 2, the rotation driver 2 5, the rotation driver 3 8, the linear driver 1 6, the linear driver 2 9, and the end jaw 11 are flexible structures.

[0022] Each driver is composed of multiple drive units. The drive unit includes three parts: a support structure 12, a flexion airbag 13, and an extension airbag 14. As Figure 14 shown, specifically, the support structure is a rhombic structure made of a single-layer TPU material, which can ensure that the drive unit always maintains a rhombic shape during movement. The flexion airbag 13 is a folded structure, composed of two layers of TPU materials and connected to the support structure. The extension airbag 14 is a rectangular structure, also composed of two layers of TPU materials, and is respectively connected to the flexion airbag and the extension airbag (diagonal). During the processing, first, the two layers of the two airbags need to be processed to form a closed airbag form. Then, the two layers of TPU materials are welded to form a rhombic support structure. Then, the two ends of the flexion airbag are respectively welded to the middle of the support structure. Finally, one side of the extension airbag is welded to the middle of the flexion airbag, and the other side is welded to the support structure, thus forming a drive unit with an antagonistic structure.

[0023] The robotic arm includes three types of lattice structure drivers, namely a rotary driver with circular connections, a linear driver with linear connections, and an end gripper with annular connections. The rotary driver consists of 6 driving units. As shown in Figure 13 , between three driving units, the initial axis and the output axis of the rotary driver are respectively set. By controlling the air pressure of the buckling and stretching airbags inside the driver, the rotation angle adjustment of the driver can be achieved. In addition, the driver can also achieve variable stiffness output of the rotary driver by changing the internal air pressure. The linear driver consists of 10 driving units. As shown in Figure 9 , each driving unit is connected in sequence in the same direction. The linear driver can change the linear length of the linear driver and the linear stiffness of the driver by changing the air pressure values of the internal buckling and stretching airbags.

[0024] The mounting base 3 consists of a circular base 15, a support plate 16, and a panel 17. As shown in Figure 4 , the support plate 16 is arranged parallel to the base 15 above the base 15 through feet. The panel 17 is arranged above the support plate 16. A rotary support shaft passes through the support plate 16 directly below the panel 17. The rotary driver 2 is placed directly above the circular base 15. A fixed baffle 18 is arranged below the support plate 16. The rotary support shaft is arranged on one side of the fixed baffle 18. The rotary support shaft is also connected to the vertical plate 19 on the base connecting part 4, so as to realize the output angle control between the mounting base 3 and the base connecting part 4.

[0025] The base connecting part 4 is a circular vertical plate 19, which provides a rotary shaft and a fixed baffle 20 for the rotary driver 2 5. The rotary driver 2 5 is installed on the circular vertical plate 19. Its initial axis is connected to the fixed baffle 20 on the base connecting part, and the output shaft 21 is connected to the linear driver 1 6.

[0026] One side of the linear driver 1 6 is connected to the rotary driver 2 5, and the other end is connected to the joint connecting part 7. The joint connecting part is a circular support structure, which provides a rotary shaft for the rotary driver 3 8. The fixed baffle above the joint connecting part is connected to the linear driver 1 6. The rotary driver 3 8 is installed on the joint connecting part. Its initial axis is connected to the linear driver 1 6, and the output axis is connected to the linear driver 2 9, which is used to control the movement included angle between the two linear drivers.

[0027] One end of the linear driver 2 9 is connected to the gripper connecting part 7, and the other end is connected to the end gripper 11 through the gripper connecting part 10. The end gripper 11 consists of 4 driving units. As shown in Figure 6 , each driving unit is connected end to end in sequence to form an annular structure. By changing the width of the driving unit, the end gripper can achieve the grasping function, which is especially suitable for grasping some delicate and irregular objects.

[0028] It should be noted that the above content only illustrates the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. For those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements all fall within the protection scope of the claims of the present invention.

Claims

1. A flexible robotic arm based on a dot matrix structure, characterized in that: It includes an installation base, a base connecting piece, a joint connecting piece, a gripper connecting piece, a rotary actuator 1, a rotary actuator 2, a rotary actuator 3, a linear actuator 1, a linear actuator 2, and an end gripper; among them, the installation base, the base connecting piece, the joint connecting piece, and the gripper connecting piece are rigid structures; while the rotary actuator 1, the rotary actuator 2, the rotary actuator 3, the linear actuator 1, the linear actuator 2, and the end gripper are flexible structures; each actuator is composed of the same diamond drive unit; The linear actuator 1 and the linear actuator 2 are respectively connected to the rotary actuator 3 on the joint connecting piece from both sides. The other side of the linear actuator 1 is connected to the rotary actuator 2 on the base connecting piece. The installation base is arranged below the base connecting piece. The rotary actuator 1 is arranged inside the installation base. The other end of the linear actuator 2 is connected to the end gripper through the gripper connecting piece.

2. The flexible robotic arm based on a dot matrix structure according to claim 1, wherein: Each drive unit includes three parts: a support structure, a buckling airbag, and an extension airbag. Specifically, the support structure is a diamond structure made of a single-layer TPU material, which can ensure that the drive unit always maintains a diamond shape during movement; the buckling airbag is a folded structure, composed of two layers of TPU materials, and is connected to the support structure; The extension airbag is a strip-shaped structure, also composed of two layers of TPU materials, and is arranged at the diagonal position of the support structure.

3. The flexible robotic arm based on a dot matrix structure according to claim 1, wherein: The processing process of the drive unit: First, the two layers of the two airbags need to be processed to form a closed airbag form; then, the two layers of TPU materials are welded to form a diamond support structure; then, the two ends of the buckling airbag are respectively welded to the middle of the support structure; finally, one side of the extension airbag is welded to the middle of the buckling airbag, and the other side is welded to the support structure, thus forming a drive unit with an antagonistic structure.

4. A flexible robotic arm based on a dot matrix structure according to claim 1, characterized in that: The robotic arm includes three types of lattice structure actuators, namely a rotary actuator with circular connection, a linear actuator with linear connection, and an end gripper with annular connection; The rotary actuator is composed of 6 drive units. Between the three drive units, the initial axis and the output axis of the rotary actuator are respectively set; by controlling the air pressure of the buckling and extension airbags inside the actuator, the rotation angle adjustment of the actuator can be realized; In addition, the actuator realizes the variable stiffness output of the rotary actuator by changing the internal air pressure; the linear actuator is composed of 10 drive units, and each drive unit is connected in sequence in the same direction; the linear actuator changes the linear length of the linear actuator and the linear stiffness of the actuator by changing the air pressure values of the internal buckling and extension airbags.

5. A flexible robotic arm based on a dot matrix structure according to claim 1, characterized in that: The installation base is composed of a circular base, a support plate, and a panel. The support plate is arranged parallel to the base above through feet. The panel is arranged above the support plate. A rotary support shaft is provided directly below the panel through the support plate. The rotary actuator 1 is placed directly above the circular base. A fixed baffle is arranged below the support plate. The rotary support shaft is arranged on one side of the fixed baffle. The rotary support shaft is also connected to the vertical plate on the base connecting piece, so as to realize the output angle control between the installation base and the base connecting piece.

6. The flexible robotic arm based on a dot matrix structure according to claim 5, characterized in that: The base connecting piece is a circular vertical plate, which provides a rotating shaft and a fixed baffle for the second rotating driver. The second rotating driver is installed on the circular vertical plate, its initial shaft is connected to the fixed baffle on the base connecting piece, and the output shaft is connected to the first linear driver.

7. The flexible robotic arm based on a dot matrix structure according to claim 6, characterized in that: One side of the first linear driver is connected to the second rotating driver, and the other end is connected to the joint connecting piece; the joint connecting piece is a circular support structure, which provides a rotating shaft for the third rotating driver; the fixed baffle above the joint connecting piece is connected to the first linear driver; the third rotating driver is installed on the joint connecting piece, its initial shaft is connected to the first linear driver, and the output shaft is connected to the second linear driver, which is used to control the movement angle between the two linear drivers.

8. The flexible robotic arm based on a dot matrix structure according to claim 1, wherein: One end of the second linear driver is connected to the jaw connecting piece, and the other end is connected to the end jaw through the jaw connecting piece; the end jaw is composed of 4 driving units, and each driving unit is connected end to end in sequence to form an annular structure.

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