A miniaturized and lightweight variable-stiffness flexible actuator and robot

Abstract

The present invention discloses a miniaturized and lightweight variable-rigidity flexible driver and robot, which belong to the technical field of robot drivers. The driver comprises a first support seat, a second support seat, an output wheel disc, an input wheel disc, a spring hook and an elastic element; the output wheel disc is rotatably connected to the second support seat, and the output wheel disc can rotate around its own axis; the input wheel disc is rotatably connected to the first support seat; the input wheel disc is also rotatably connected to the output wheel disc, and the input wheel disc can rotate around its own axis; one end of the elastic element is connected to the input wheel disc, and the other end of the elastic element is connected to the spring hook, which is connected to the output wheel disc and can move radially along the output wheel disc to change the preload of the spring. The driver stiffness can be adjusted without additionally setting a stiffness adjustment motor. The driver has the characteristics of miniaturization and lightweight, and solves the problem of large volume and weight caused by the need to additionally set a motor for stiffness adjustment in the current driver.

Description

Technical Field

[0001] The present invention relates to the technical field of robot drivers, and in particular to a miniaturized, lightweight, variable-rigidity flexible driver and a robot. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The exoskeleton robot can enhance the wearer's physical abilities. A driver is set up in the exoskeleton robot to provide the wearer with the necessary support force. The stiffness of the driver will also change as the wearer's movements and needs change.

[0004] The stiffness adjustment of the current driver requires that a stiffness adjustment motor be provided in the driver, and the stiffness of the driver is adjusted by adjusting the preload force of the elastic member in the driver through the stiffness adjustment motor.

[0005] However, the current driver has a large overall size and weight due to the addition of a stiffness adjustment motor, which cannot meet the requirements of miniaturization and lightweight. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a miniaturized and lightweight variable stiffness flexible driver and robot, which can adjust the stiffness of the driver without the need for an additional stiffness adjustment motor, and has the characteristics of miniaturization and lightweight.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] In the first aspect, a miniaturized and lightweight variable stiffness flexible actuator is proposed, comprising a first support seat, a second support seat, an output wheel disc, an input wheel disc, a spring hook and an elastic element;

[0009] The output wheel disc is rotatably connected to the second support seat, and the output wheel disc can rotate around its own axis; the input wheel disc is rotatably connected to the first support seat; the input wheel disc is also rotatably connected to the output wheel disc, and the input wheel disc can rotate around its own axis;

[0010] One end of the elastic element is connected to the input wheel disc, the other end of the elastic element is connected to the spring hook, the spring hook is connected to the output wheel disc and can move along the radial direction of the output wheel disc.

[0011] Furthermore, it comprises a plurality of spring hooks and a plurality of elastic elements; the plurality of spring hooks and the plurality of elastic elements are evenly distributed along the circumference of the output wheel disc.

[0012] Furthermore, the elastic element is connected to the spring hook and the input wheel in a detachable connection manner.

[0013] Furthermore, the stiffness adjustment bolt passes through the spring hook and is connected to the output wheel disc, and rotating the stiffness adjustment bolt can drive the spring hook to move radially along the output wheel disc.

[0014] Furthermore, a through hole is arranged on the spring hook, a threaded hole is arranged on the output wheel, the stiffness adjustment bolt passes through the through hole and is threadedly connected with the threaded hole, and the stiffness adjustment bolt is connected with the through hole at the through hole through a fourth bearing.

[0015] Furthermore, an angle sensor is provided on the second support seat;

[0016] Angle sensor, used to measure the rotation angle of the output wheel.

[0017] Furthermore, the input wheel is connected to the output shaft of the motor through a transmission device, and the motor is connected to the motor support seat.

[0018] Furthermore, the first support seat and the second support seat are both connected to the floor; the motor support seat is slidably connected to the motor fixing plate, and the motor fixing plate is connected to the floor.

[0019] Furthermore, the motor support seat is connected to the pre-tightening support via a third bolt, the pre-tightening support is connected to the floor, and rotating the third bolt can drive the motor support seat to move along the motor fixing plate.

[0020] In a second aspect, a robot is proposed, comprising a miniaturized and lightweight variable stiffness flexible actuator proposed in the first aspect.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention discloses a miniaturized and lightweight variable stiffness flexible actuator and robot. The actuator is connected to an input wheel disc at one end of an elastic element and to a spring hook at the other end. The spring hook is connected to an output wheel disc and can move radially along the output wheel disc. The preload force of the elastic element is changed by moving the spring hook radially along the output wheel disc, so that the stiffness of the actuator can be adjusted without the need for an additional stiffness adjustment motor. The actuator has the characteristics of miniaturization and lightweight.

[0023] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0025] Figure 1 It is a schematic diagram of the overall three-dimensional structure of a miniaturized and lightweight variable-rigidity flexible actuator disclosed in an embodiment;

[0026] Figure 2 A cross-sectional view of a stiffness adjustment portion and an output portion disclosed in an embodiment.

[0027] Among them: 1. preload support, 2. motor, 3. motor support seat, 4. motor rotating disk, 5. first bolt, 6. wire rope, 7. motor fixing plate, 8. second bolt, 9. third bolt, 10. floor, 11. fourth bolt, 12. first support seat, 13. fifth bolt, 14. first bearing, 15. input wheel disc, 16. elastic element, 17. output wheel disc, 18. second bearing, 19. sixth bolt, 20. seventh bolt, 21. sensor fixing bracket, 22. angle sensor, 23. second support seat, 24. third bearing, 25. stiffness adjustment bolt, 26. nut support, 27. fourth bearing, 28. gasket, 29. spring hook, 30. magnet, 31. copper sleeve. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0032] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0033] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0034] Example 1

[0035] Exoskeleton robots have the function of enhancing the wearer's physical ability. They can improve the wearer's strength and endurance in daily activities, and can also assist the wearer in recovering motor function in medical rehabilitation. The design and application of exoskeleton robots must not only consider improving the wearer's motor performance, but also consider the safety and comfort of the robot during human-machine interaction. The interaction between the exoskeleton robot and the operator must be highly flexible, and the exoskeleton robot must be able to accurately control the applied force and torque. This requires that the actuator in the exoskeleton robot not only provide the necessary support for the wearer, but also be able to flexibly adjust its stiffness according to the wearer's movements and needs.

[0036] In order to meet these complex requirements, domestic and foreign scholars have developed a variety of flexible actuators. For example, CN118003314 A discloses a double-spring series elastic actuator that can withstand bidirectional loads and ensure that the input and output ends of the series elastic actuator are on the same axis, effectively avoiding the generation of additional deflection torque. CN115737362 A discloses a rigid-flexible switching series elastic actuator that can switch between rigid mode and flexible mode, effectively avoiding secondary injuries to the wearer during recovery training. However, the stiffness of the above two series elastic actuators is fixed and cannot adapt to complex environments. CN 117697811 A discloses a rotary variable stiffness actuator based on a cam-arc leaf spring mechanism, which can directly adjust the fulcrum position of the mechanism through a stiffness adjustment motor to achieve stiffness adjustment of the actuator. CN 113334360 A discloses a reconfigurable compact variable stiffness actuator, which can be installed on a transmission shaft assembly to obtain a variable stiffness actuator with different stiffness curves such as increasing stiffness, decreasing stiffness and fixed stiffness. CN 112894787 A discloses a variable stiffness module and a modular flexible variable stiffness drive mechanism, wherein the output shaft of the stiffness motor is connected to a T-shaped lead screw through a transmission structure, thereby driving a spring compression block to compress the spring structure, causing the cam to rotate, thereby achieving adjustment of the driver stiffness. However, the variable stiffness driver is too large in size and cannot meet the requirements of miniaturization and lightness.

[0037] In summary, the variable stiffness elastic actuator can adjust the stiffness to adapt to different application scenarios and operation requirements, thereby providing the exoskeleton robot with higher adaptability and functionality. However, the variable stiffness actuator in the prior art requires an additional motor to adjust the stiffness, resulting in a large overall size and weight of the actuator. Therefore, in order to meet the requirements of miniaturization and lightweight use of the actuator, further exploration and improvement are needed in terms of size and stiffness adjustment methods.

[0038] In order to make the variable-rigidity flexible actuator have the characteristics of miniaturization and lightness, this embodiment discloses a miniaturized and light-weight variable-rigidity flexible actuator.

[0039] like Figure 1 , Figure 2 As shown, a miniaturized and lightweight variable stiffness flexible actuator disclosed in this embodiment includes: a first support seat 12, a second support seat 23, an output wheel disc 17, an input wheel disc 15, a spring hook 29 and an elastic element 16;

[0040] The output wheel disc 17 is rotatably connected to the second support seat 23, and the output wheel disc 17 can rotate around its own axis; the input wheel disc 15 is rotatably connected to the first support seat 12; the input wheel disc 15 is also rotatably connected to the output wheel disc 17, and the input wheel disc 15 can rotate around its own axis;

[0041] A first end of the elastic element 16 is connected to the input wheel disc 15 , and a second end of the elastic element 16 is connected to a spring hook 29 . The spring hook 29 is connected to the output wheel disc 17 and can move radially of the output wheel disc 17 .

[0042] like Figure 2 As shown, one end of the input wheel 15 is connected to the first support seat 12 through the first bearing 14; the other end of the input wheel 15 is connected to one end of the output wheel 17 through the second bearing 18, and the other end of the output wheel 17 is connected to the second support seat 23 through the third bearing 24; therefore, the input wheel 15 can rotate around its own axis relative to the output wheel 17.

[0043] Preferably, the output wheel disc 17 is coaxially arranged with the input wheel disc 15 .

[0044] The elongation direction of the elastic element 16 of the present embodiment is consistent with the radial direction of the output wheel disc 17. In order to change the preload force of the elastic element 16 and thus change the stiffness of the driver disclosed in the present embodiment, a spring hook 29 is provided. One end of the elastic element 16 is connected to the input wheel disc 15 and can rotate with the input wheel disc 15. The other end of the elastic element 16 is connected to the spring hook 29. The spring hook 29 is connected to the output wheel disc 17 and can rotate with the output wheel disc 17. In addition, the spring hook 29 can also move in the radial direction of the output wheel disc 17. By moving the spring hook 29 in the radial direction of the output wheel disc 17, the length of the elastic element 16 is changed, thereby changing the preload force of the elastic element.

[0045] In a specific implementation, the stiffness adjustment bolt 25 passes through the spring hook 29 and is connected to the output wheel disc 17 . Rotating the stiffness adjustment bolt 25 can drive the spring hook 29 to move radially along the output wheel disc 17 .

[0046] Specifically, a guide protrusion is provided on the spring hook 29 ; a guide groove is provided on the output wheel disc 17 ; the guide protrusion is slidably connected to the guide groove to provide guidance for the radial movement of the spring hook 29 along the output wheel disc 17 .

[0047] A through hole is set on the spring hook 29, and a threaded hole is set on the output wheel 17. The stiffness adjustment bolt 25 passes through the through hole and is threadedly connected to the threaded hole. The stiffness adjustment bolt 25 is connected to the through hole through a fourth bearing 27 at the through hole. The fourth bearing 27 can reduce friction and enable the stiffness adjustment bolt 25 to rotate around its own axis relative to the spring hook 29.

[0048] Preferably, a gasket 28 is arranged between the stiffness adjusting bolt 25 and the spring hook 29, and a nut support 26 is arranged between the spring hook 29 and the output wheel disc 17. The stiffness adjusting bolt 25 passes through the through hole on the spring hook 29 and the nut support 26 in sequence, and is threadedly connected with the threaded hole on the output wheel disc 17. The nut support 26 is threadedly connected with the stiffness adjusting bolt 25. By providing the nut support 26, it can be ensured that when the stiffness adjusting bolt 25 is rotated, the nut support 26, the fourth bearing 27 and the spring hook 29 move together along the radial direction of the output wheel disc 17.

[0049] The present embodiment discloses a miniaturized and lightweight variable-rigidity flexible actuator, comprising a plurality of spring hooks 29 and a plurality of elastic elements 16; the plurality of spring hooks 29 and the plurality of elastic elements 16 are evenly distributed along the circumference of the output wheel disc 17; each elastic element 16 is connected to the spring hook 29 and the input wheel disc 15 in a detachable connection manner, and by changing the number of elastic elements 16 or replacing them with elastic elements 16 of different stiffness, the adjustment range of the actuator stiffness can be changed to adapt to different working conditions.

[0050] Preferably, the elastic element 16 is a spring.

[0051] In this embodiment, an angle sensor 22 is also disposed on the second support seat 23;

[0052] The angle sensor 22 is used to measure the rotation angle of the output wheel disc 17 .

[0053] like Figure 2 As shown, the angle sensor 22 is fixedly connected to the sensor fixing bracket 21, and the sensor fixing bracket 21 is fixedly connected to the second support seat 23 by the seventh bolt 20; in addition, a magnet 30 matching the angle sensor 22 is also provided at the end where the output wheel disc 17 is connected to the second support seat 23, and the angle sensor 22 determines the rotation angle of the output wheel disc 17 by sensing with the magnet 30.

[0054] like Figure 1 As shown, the input wheel 15 of this embodiment is connected to the output shaft of the motor 2 through a transmission device, and the motor 2 is connected to the motor support seat 3. The output shaft of the motor 2 rotates, which can drive the input wheel 15 to rotate through the transmission device.

[0055] Among them, the transmission device includes a motor rotating disc 4 and a wire rope 6; the motor rotating disc 4 is fixedly connected to the output shaft of the motor 2, the motor rotating disc 4 can rotate along with the output shaft of the motor 2, and the two ends of the wire rope 6 are respectively connected to the motor rotating disc 4 and the input wheel disc 15; the rotation of the motor rotating disc 4 can drive the input wheel disc 15 to rotate through the wire rope 6.

[0056] Preferably, the transmission device includes two steel ropes 6, and two ends of each steel rope 6 are connected to the motor rotating disc 4 and the input wheel disc 15 respectively.

[0057] The motor 2 is connected to the motor support seat 3 via a first bolt 5 .

[0058] Grooves are respectively arranged on the input wheel disc 15 and the motor rotating disc 4, and a copper sleeve 31 is arranged in each groove. One end of the steel wire rope 6 is connected to the copper sleeve 31 on the input wheel disc 15, and the other end of the steel wire rope 6 is connected to the copper sleeve 31 on the motor rotating disc 4. Through the arrangement of the copper sleeve 31, when the motor rotating disc 4 rotates, the input wheel disc 15 can be driven to rotate through the steel wire rope 6.

[0059] The first support seat 12 and the second support seat 23 of this embodiment are both connected to the floor 10; the motor support seat 3 is slidably connected to the motor fixing plate 7, and the motor fixing plate 7 is connected to the floor 10; wherein the sliding direction of the motor support seat 3 is to move toward or away from the input wheel disc 15. This embodiment realizes the adjustment of the distance between the input wheel disc 15 and the motor 2 by setting the motor support seat 3 and the motor fixing plate 7 to be slidably connected.

[0060] In specific implementation, the motor support seat 3 of this embodiment is connected to the preload support 1 through the third bolt 9, and the preload support 1 is connected to the floor 10. Rotating the third bolt 9 can drive the motor support seat 3 to move along the motor fixing plate 7.

[0061] Preferably, the motor support base 3 is connected to the preload support 1 via two third bolts 9 , and the two third bolts 9 are spaced apart along the height direction of the motor support base 3 .

[0062] The motor support seat 3 is located between the preload support 1 and the first support seat 12 .

[0063] The first support base 12 is connected to the floor 10 via a fifth bolt 13 , and the second support base 23 is connected to the floor 10 via a sixth bolt 19 .

[0064] The preload support 1 is connected to the motor fixing plate 7 via the second bolt 8 , and the motor fixing plate 7 is connected to the floor 10 via the fourth bolt 11 .

[0065] The present embodiment discloses a miniaturized and lightweight variable-rigidity flexible actuator. When the output disc is not in contact with the load and is in a free state, the motor 2 drives the motor rotating disc, the input disc and the output disc to move simultaneously, and no relative rotation occurs between the input disc and the output disc. When the output disc is in contact with the load and the output torque is less than the resistance torque of the load, the motor 2 drives the motor rotating disc and the input disc to rotate, while the output disc remains stationary, causing the spring to produce elastic deformation until the output torque generated by the deformation of the spring is greater than or equal to the resistance torque of the load, at which time the motor 2 drives the motor disc, the input disc, the output disc and the load to rotate together.

[0066] The present embodiment discloses a miniaturized and lightweight variable-stiffness flexible actuator, which can adjust the preload force of the elastic element 16 by rotating the stiffness adjustment bolt 25, thereby adjusting the stiffness of the actuator, thereby improving the convenience of adjusting and maintaining the stiffness of the actuator; the stiffness of the actuator can also be adjusted by adjusting the stiffness and number of the elastic element 16, so that the actuator disclosed in the present embodiment has reconfigurability, a simple structure, and a small size; and each elastic element is connected to a separate spring hook, so that the preload force of each elastic element can be fine-tuned, making the adjustment of the variable stiffness of the actuator more accurate.

[0067] In this embodiment, the stiffness can be adjusted manually without the need for an additional stiffness adjustment motor, thereby reducing the weight of the driver and the overall weight of the driver, and having the characteristics of miniaturization and lightness.

[0068] Example 2

[0069] In this embodiment, a robot is disclosed, comprising a miniaturized, lightweight, variable-rigidity flexible actuator proposed in the first aspect.

[0070] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the present embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0071] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A miniaturized and lightweight variable stiffness flexible actuator, characterized in that: It includes a first support seat, a second support seat, an output wheel disc, an input wheel disc, a plurality of spring hooks and a plurality of elastic elements; The output wheel disc is rotatably connected to the second support seat, and the output wheel disc can rotate around its own axis; the input wheel disc is rotatably connected to the first support seat; the input wheel disc is also rotatably connected to the output wheel disc, and the input wheel disc can rotate around its own axis; A plurality of spring hooks and a plurality of elastic elements are evenly arranged along the circumference of the output wheel disc; one end of the elastic element is connected to the input wheel disc, and the other end of the elastic element is connected to the spring hook, and the spring hook is connected to the output wheel disc and can move along the radial direction of the output wheel disc; A through hole is arranged on the spring hook, and a threaded hole is arranged on the output wheel disc. The stiffness adjusting bolt passes through the through hole and is threadedly connected with the threaded hole. The stiffness adjusting bolt is connected with the through hole through a fourth bearing at the through hole. Rotating the stiffness adjusting bolt can drive the spring hook to move radially along the output wheel disc.

2. A miniaturized and lightweight variable stiffness flexible actuator as claimed in claim 1, characterized in that: The elastic element is connected with the spring hook and the input wheel disc in a detachable connection manner.

3. A miniaturized and lightweight variable stiffness flexible actuator as claimed in claim 1, characterized in that: An angle sensor is arranged on the second supporting seat; Angle sensor, used to measure the rotation angle of the output wheel.

4. A miniaturized and lightweight variable stiffness flexible actuator as claimed in claim 1, characterized in that: The input wheel is connected to the output shaft of the motor through a transmission device, and the motor is connected to the motor support seat.

5. A miniaturized and lightweight variable stiffness flexible actuator as claimed in claim 4, characterized in that: The first support seat and the second support seat are both connected to the floor; the motor support seat is slidably connected to the motor fixing plate, and the motor fixing plate is connected to the floor.

6. A miniaturized and lightweight variable stiffness flexible actuator as claimed in claim 5, characterized in that: The motor support seat is connected to the pre-tightening support via a third bolt, and the pre-tightening support is connected to the floor. Rotating the third bolt can drive the motor support seat to move along the motor fixing plate.

7. A robot, characterized in that: A miniaturized, lightweight, variable-rigidity flexible actuator comprising the method described in any one of claims 1 to 6.

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