Flexible side-sway mechanism and dexterous hand

Abstract

The invention provides a flexible side swing mechanism and a dexterous hand, the flexible side swing mechanism comprises a matching pair and a plane cam, and the matching pair is used for being connected to a finger mechanism; the plane cam is used for moving on the palm body, at least one set of open holes are formed in the plane cam, the number of the open holes in each set is two, and an elastic plate is formed between the two open holes in each set; the elastic plate is clamped by the matching pair, in the moving process of the plane cam, the elastic plate moves relative to the matching pair, then the finger mechanism is driven to swing laterally, flexible lateral swing is provided for the finger mechanism by means of the elastic characteristic of the elastic plate, and the size of the lateral swing mechanism is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of robots, and in particular to a compliant side-swing mechanism and a dexterous hand. Background Art

[0002] As the end effector of a robot, the core function of a manipulator is to simulate the actions of a human hand and complete tasks such as grasping and operating tools. As a high-end form of a manipulator, a dexterous hand is closer to the human hand in terms of structural design. Each finger is usually equipped with multiple degrees of freedom, among which the bending degree of freedom and the lateral side-swing degree of freedom are crucial, endowing it with more flexible operating capabilities.

[0003] Currently, most dexterous hand designs focus on the bending degree of freedom, and the transmission mechanism mostly uses a rigid structure. This design performs stably in simple operating scenarios, but its functions are relatively single. Only a small number of dexterous hands have the side-swing degree of freedom, and most of them use an underactuated method to achieve multi-finger side-swing linkage through rigid components such as gears and linkages. However, realizing independent and compliant passive side-swing motion for each finger remains a major technical bottleneck in current dexterous hand designs.

[0004] In an actual operating environment, a dexterous hand will inevitably collide with the environment. Due to the lack of passive compliance ability in most existing designs, it is easy to be damaged during collisions, which not only increases the maintenance cost but also limits the application scope of dexterous hands in complex and unknown environments.

[0005] For example, the design scheme of a dexterous hand side-swing mechanism disclosed in the patent document CN118636177A uses a combination of a single driving component and a coupled rigid linkage mechanism to achieve synchronous side-swing motion of multiple finger joints. Although there are breakthroughs in structural design, this scheme still does not solve the problem of the lack of passive compliance function. Summary of the Invention

[0006] The purpose of the present invention is to provide a compliant side-swing mechanism and a dexterous hand for the deficiencies in the prior art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A compliant side-swing mechanism, comprising:

[0009] A mating pair for connecting to a finger mechanism;

[0010] A planar cam for moving on a palm body, and at least one set of openings is provided on the planar cam, the number of openings in each set is two, and an elastic plate is formed between the two openings in each set;

[0011] The elastic plate is clamped by the mating pair. During the movement of the planar cam, the elastic plate moves relative to the mating pair, thereby driving the finger mechanism to swing laterally, and using the elastic characteristic of the elastic plate to provide compliant lateral swing for the finger mechanism.

[0012] As a preferred embodiment, the mating pair includes:

[0013] A connection end for connecting the finger mechanism;

[0014] A clamping end, the clamping end includes two clamping blocks and a clamping slot located between the two clamping blocks;

[0015] The elastic plate is slidably arranged in the clamping slot, and the two clamping blocks are respectively located in the through holes on both sides of the elastic plate.

[0016] As a preferred embodiment, the contour of the through hole includes a straight surface and a curved surface connected end to end in sequence, and the elastic plate is formed between the straight surfaces of the two through holes.

[0017] As a preferred embodiment, the width of the through hole gradually decreases from the middle in the length direction of the elastic plate to both ends in the length direction of the elastic plate.

[0018] As a preferred embodiment, a guiding assembly is arranged between the planar cam and the palm body.

[0019] As a preferred embodiment, the un-elastic-deformed elastic plate is inclined with respect to the guiding direction of the guiding assembly.

[0020] As a preferred embodiment, the guiding assembly includes:

[0021] A guiding slot opened on the palm body, and the length direction of the guiding slot defines the guiding direction of the guiding assembly;

[0022] A guiding post arranged on the planar cam, and the guiding post slides in the guiding slot.

[0023] As a preferred embodiment, it further includes:

[0024] A lateral swing power member, which is in transmission connection with the planar cam.

[0025] As a preferred embodiment, the finger mechanism is arranged on the palm body in a manner of rotating around a rotation axis, and the mating pair and the through holes of the compliant lateral swing mechanism are located below the rotation axis.

[0026] As a preferred embodiment, the planar cam of the compliant lateral swing mechanism is located between the palm body and the finger mechanism.

[0027] The present invention also provides a dexterous hand, which includes the compliant side-swing mechanism of the above embodiment, and further includes a palm body and a finger mechanism.

[0028] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0029] Through the cooperative design of the mating pair and the elastic plate, not only the side-swing movement of the finger mechanism is realized, but also each finger mechanism is given an independent compliant characteristic, improving the safety of the dexterous hand during the interaction with the environment.

[0030] The swinging movement and compliant characteristics of multiple finger mechanisms can be designed and integrated into an integrated structure, reducing the number of components and structural complexity, effectively reducing the size of the side-swing mechanism, and being beneficial to the miniaturization and light weight of the dexterous hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of the compliant side-swing mechanism of the present invention;

[0032] Figure 2 is Figure 1 a cross-sectional view taken along the A-A direction in

[0033] Figure 3 is a schematic assembly diagram of the mating pair and the planar cam of the present invention;

[0034] Figure 4 is a schematic structural diagram of the dexterous hand of the present invention.

[0035] In the figure: 100 compliant side-swing mechanism, 110 mating pair, 111 connection end, 112 engaging end, 112a engaging block, 112b engaging slot, 120 planar cam, 121 opening, 121a straight surface, 121b curved surface, 122 elastic plate, 130 side-swing power member, 140 guiding assembly, 141 guiding groove, 142 guiding post, 150 snap ring, 200 palm body, 300 finger mechanism, 310 rotating shaft. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalent schemes, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0037] First Embodiment

[0038] As Figure 1As shown in the figure, the present invention provides a compliant side-swing mechanism 100, including:

[0039] A mating pair 110, which is used to be connected to the finger mechanism 300;

[0040] A planar cam 120, which is used to move on the palm body 200. At least one set of through holes 121 are formed on the planar cam 120. The number of each set of through holes 121 is two, and an elastic plate 122 is formed between the two through holes 121 of each set;

[0041] The elastic plate 122 is clamped by the mating pair 110. During the movement of the planar cam 120, the elastic plate 122 moves relative to the mating pair 110, thereby driving the finger mechanism 300 to swing sidewise, and using the elastic characteristics of the elastic plate 122 to provide compliant side-swing for the finger mechanism 300.

[0042] Connect the mating pair 110 to the finger mechanism 300, so that the mating pair 110 is clamped with the elastic plate 122 on the planar cam 120. At the same time, the elastic plate 122 can move relative to the mating pair 110. In this way, after the external force drives the planar cam 120 to move on the palm body 200, not only the left and right side-swing of the finger mechanism 300 is realized, but also the elastic characteristics of the elastic plate 122 are used to provide compliance for the finger mechanism 300 during the side-swing process, and it can adapt to different working environments and task requirements. For example, when the finger mechanism 300 encounters an obstacle during side-swing, the elastic plate 122 will undergo elastic deformation, absorbing part of the collision energy, thereby reducing the impact on the finger mechanism 300 and the grasped object, and making the side-swing movement smoother and softer. This mechanism is mainly composed of components such as the mating pair 110 and the planar cam 120, with a relatively simple structure, small occupied space, and is convenient for installation and layout in a limited space such as the palm.

[0043] As Figures 1 to 3 shown, the mating pair 110 is fixed on the finger mechanism 300. Specifically, a snap ring 150 is sleeved on the finger mechanism 300, and the mating pair 110 can be connected to the snap ring 150 to realize the fixation of the mating pair 110 on the finger mechanism 300. Wherein the mating pair 110 can be integrally connected with the snap ring 150. In this way, during the assembly process of the mating pair 110 and the finger mechanism 300, as long as the lower end of the finger mechanism 300 is inserted into the snap ring 150 of the mating pair 110 until the snap ring 150 is tightly sleeved with the finger mechanism 300. Of course, the fixation can also be strengthened by screwing a screw through the snap ring 150 and screwing it with the finger mechanism 300.

[0044] Refer to Figure 2, the mating pair 110 includes:

[0045] A connecting end 111 for connecting the finger mechanism 300;

[0046] An engaging end 112, which includes two engaging blocks 112a and a slot 112b located between the two engaging blocks 112a;

[0047] The elastic plate 122 is slidably disposed in the slot 112b, and the two engaging blocks 112a are respectively located in the openings 121 on both sides of the elastic plate 122.

[0048] The connecting end 111 and the engaging end 112 are respectively located at both ends of the mating pair 110 in the length direction. Since the mating pair 110 and the planar cam 120 are arranged between the finger mechanism 300 and the palm body 200, the length of the mating pair 110 is adapted to the installation space between the finger mechanism 300 and the palm body 200.

[0049] The cross-section of the mating pair 110 can be circular, square, etc. Taking the cross-section of the mating pair 110 as circular as an example, the cross-sections of the two engaging blocks 112a are respectively semi-circular.

[0050] The width of the slot 112b is slightly larger than the thickness of the elastic plate 122, so that the elastic plate 122 can move in the slot 112b along with the planar cam 120.

[0051] As Figure 1 and Figure 3 shown, since the planar cam 120 is arranged between the finger mechanism 300 and the palm body 200, the thickness of the planar cam 120 is adapted to the installation space between the finger mechanism 300 and the palm body 200. Among them, one side in the thickness direction of the planar cam 120 is in contact with the palm body 200, and the other side in the thickness direction of the planar cam 120 keeps a small gap from the finger mechanism 300 to realize the sliding of the planar cam 120 on the palm body 200. At the same time, the mating pair 110 is perpendicular to the planar cam 120. By reasonably designing the thickness of the planar cam 120, the cooperation modes with the palm body 200 and the finger mechanism 300, and the layout of the mating pair 110, the occupied space of the compliant side-sway mechanism 100 in the dexterous hand is effectively reduced.

[0052] Refer to Figure 1, at least one set of openings 121 are formed on the planar cam 120, and one set of openings 121 corresponds to one finger mechanism 300. It should be noted that the dexterous hand has five finger mechanisms 300, corresponding to the thumb, index finger, middle finger, ring finger and little finger respectively. However, not every finger requires the same side-swing drive configuration. According to actual needs, openings 121 and mating pairs 110 can be selectively provided for some finger mechanisms 300.

[0053] As Figure 1 and Figure 3 shown, the finger mechanism 300 is arranged on the palm body 200 in a manner of rotating around the rotation axis 310, and the rotation axis 310 is perpendicular to the palm body 200. In this embodiment, the rotation axis 310 is fixed on the palm body 200, and the finger mechanism 300 is sleeved on the rotation axis 310, so that the finger mechanism 300 can swing left and right (side-swing) around the vertical direction of the palm body 200.

[0054] The mating pair 110 of the compliant side-swing mechanism 100 and its corresponding opening 121 are located below the rotation axis 310. This layout makes full use of the vertical space of the palm body 200, avoids interference with other components, and at the same time provides sufficient space for the movement of the planar cam 120.

[0055] When the planar cam 120 moves up and down relative to the palm body 200, since the elastic plate 122 is inclined relative to the vertical direction, the elastic plate 122 of the planar cam 120 will move in the slot 112b of the mating pair 110. The force generated by this movement is transmitted to the finger mechanism 300 through the mating pair 110, causing the finger mechanism 300 to perform a side-swing action around the rotation axis 310, that is, the linear motion of the planar cam 120 is converted into the side-swing motion of the finger mechanism 300. And because the elastic plate 122 has elasticity, when the finger mechanism 300 is subjected to external forces in the left and right directions, the elastic plate 122 undergoes elastic deformation to achieve the compliant function of the side-swing of the finger mechanism 300.

[0056] The inclination angle of the elastic plate 122 relative to the vertical direction, the length of the elastic plate 122, etc. determine the side-swing angle of the finger mechanism 300. Refer to Figure 1 , the little finger, ring finger, middle finger, and index finger are arranged from left to right.

[0057] Taking the little finger as an example, the elastic plate 122 is inclined to the right. When the elastic plate 122 moves downward within the slot 112b of the mating pair 110, the finger mechanism 300 swings to the right around the rotation axis 310. When the elastic plate 122 moves upward within the slot 112b of the mating pair 110, the finger mechanism 300 swings to the left around the rotation axis 310.

[0058] Taking the ring finger as an example, it is the same as the little finger, and the elastic plate 122 is inclined to the right. However, the inclination angle of the elastic plate 122 corresponding to the ring finger is smaller than that of the elastic plate 122 corresponding to the little finger.

[0059] Taking the index finger as an example, the elastic plate 122 is inclined to the right. When the elastic plate 122 moves downward within the slot 112b of the mating pair 110, the finger mechanism 300 swings to the left around the rotation axis 310. When the elastic plate 122 moves upward within the slot 112b of the mating pair 110, the finger mechanism 300 swings to the right around the rotation axis 310.

[0060] It should be noted that the number of groups of the openings 121 on the planar cam 120 can be equal to the number of the finger mechanisms 300, and the inclination angles of the elastic plates 122 corresponding to each finger mechanism 300 are different, so that multiple finger mechanisms 300 swing sideways simultaneously and the sideways swing angles are different. Therefore, the sideways swing movements of each finger mechanism 300 are independent and optional, greatly enhancing the flexibility and adaptability of the dexterous hand for grasping.

[0061] Reference Figure 1 and Figure 3 As can be seen, the number of each group of the openings 121 is two, and an elastic plate 122 is formed between the two openings 121 of each group. When the elastic plate 122 is in an un-elastic-deformed state, the two openings 121 of each group are symmetrically arranged with respect to the elastic plate 122. The contour of the opening 121 includes a straight surface 121a and a curved surface 121b that are connected end to end in sequence. The straight surfaces 121a of the two openings 121 face inward, and the elastic plate 122 is formed between the straight surfaces 121a of the two openings 121, while the curved surface 121b is arranged outward.

[0062] It can be seen from this that the elastic plate 122 in the un-elastic-deformed state is linear and is clamped within the slot 112b of the mating pair 110. The planar cam 120 is made of materials such as stainless steel, and the thickness of the elastic plate 122 is relatively thin. Therefore, the elastic plate 122 has the ability of elastic deformation.

[0063] The contour of the opening 121 defines the compliant range of the lateral swing of the finger mechanism 300, that is, the distance from the straight surface 121a to the curved surface 121b determines the range of the deformation ability of the elastic plate 122 in the direction of the curved surface 121b. In this embodiment, the width of the opening 121 gradually decreases from the middle in the length direction of the elastic plate 122 to both ends in the length direction of the elastic plate 122, so that the elastic plate 122 has different deformation abilities at different length positions, thereby realizing gradient compliance. During the lateral swing of the finger mechanism 300, the middle part of the elastic plate 122 can provide greater compliance to buffer external impacts.

[0064] As Figure 1 shown, a guiding component 140 is arranged between the planar cam 120 and the palm body 200 to provide moving guidance for the planar cam 120 relative to the palm body 200. The guiding direction of the guiding component 140 is the vertical direction. It can be seen that the non-elastically deformed elastic plate 122 is inclined relative to the guiding direction of the guiding component 140.

[0065] Refer to Figure 1 , the guiding component 140 includes:

[0066] A guiding groove 141 is opened on the palm body 200, and the length direction of the guiding groove 141 defines the guiding direction of the guiding component 140;

[0067] A guiding post 142 is arranged on the planar cam 120, and the guiding post 142 slides in the guiding groove 141.

[0068] The length direction of the guiding groove 141 defines the guiding direction of the guiding component 140 as the vertical direction. The guiding post 142 slides in the guiding groove 141, thereby providing precise moving guidance for the planar cam 120 relative to the palm body 200 and ensuring that the planar cam 120 can only move up and down along the vertical direction. At the same time, the length of the guiding groove 141 limits the distance of the up and down movement of the planar cam 120, preventing the planar cam 120 from moving excessively and getting out of the normal working range.

[0069] The number of the guiding components 140 can be multiple, which further improves the motion stability and guiding accuracy of the planar cam 120. In this embodiment, one guiding component 140 is arranged between two adjacent finger mechanisms 300.

[0070] Continue to refer to Figure 1, due to the height differences existing in the mating pairs 110 of multiple finger mechanisms 300, to accommodate the height differences, the planar cam 120 is arranged at an angle to compensate for the height differences between the mating pairs 110. Similarly, there are height differences among multiple guiding components 140.

[0071] As Figure 1 shown, the compliant side-swing mechanism 100 further includes:

[0072] A side-swing power member 130, which is in transmission connection with the planar cam 120.

[0073] The side-swing power member 130 can be a small motor, which is fixed on the palm body 200 and is located below the finger mechanism 300. This layout makes full use of the space of the palm body 200, does not interfere with the normal movement of the finger mechanism 300, and is also beneficial to the compactness of the overall structure, meeting the design trend of miniaturization and light weight of the dexterous hand. Through the rotation of the side-swing power member 130, it is converted into the up-and-down movement of the planar cam 120. For example, when the side-swing power member 130 rotates forward, the planar cam 120 moves downward; when the side-swing power member 130 rotates in reverse, the planar cam 120 moves upward.

[0074] The side-swing power member 130 can be in transmission connection with the planar cam 120 through gears, racks, etc. Different reduction ratios can be designed according to parameters such as gears and racks. A larger reduction ratio can convert the high-speed low-torque output by the motor into a low-speed high-torque suitable for driving the planar cam 120, realizing the function of amplifying the driving force and ensuring that the planar cam 120 can overcome various resistances and stably drive the finger mechanism 300 to swing sidewise.

[0075] The number of the side-swing power members 130 is one, and by driving one planar cam 120 to move up and down, it can drive multiple finger mechanisms 300 to swing sidewise, avoiding the design where each finger mechanism 300 corresponds to one power, reducing the space size of the compliant side-swing mechanism 100, and further realizing a more compact structural design of the dexterous hand.

[0076] It should be noted that due to the elastic deformation ability of the elastic plate 122, the finger mechanism 300 still has compliant ability when subjected to external forces in the case where the side-swing power member 130 does not rotate (i.e., in the locked state).

[0077] The working steps of the compliant side-swing mechanism 100 are as follows:

[0078] Driven by the side-swing power member 130, the planar cam 120 moves vertically under the guiding action of the guiding assembly 140. At this time, the elastic plate 122 of the planar cam 120 and the slot 112b of the mating pair 110 move relative to each other, causing each finger mechanism 300 to swing laterally. When the finger mechanism 300 encounters an external resistance, the elastic plate 122 will bend and deform, absorbing part of the energy, thus making the lateral swing movement more compliant.

[0079] In summary, through the cooperative design of the mating pair 110 and the elastic plate 122, not only the lateral swing movement of the finger mechanism 300 is realized, but also each finger mechanism 300 is endowed with an independent compliant characteristic, improving the safety of the interaction process between the dexterous hand and the environment. The swinging movement and compliant characteristics of multiple finger mechanisms 300 can be designed and integrated into an integrated structure, and the motion transmission is carried out using a principle similar to the cam drive, that is, the linear motion of the planar cam 120 is converted into the lateral swing movement of the finger mechanism 300. Compared with the traditional rigid link and gear drive methods, the integrated design reduces the number of components and structural complexity, effectively reducing the size of the lateral swing mechanism, which is beneficial to the miniaturization and lightweight of the dexterous hand.

[0080] Second Embodiment

[0081] As Figure 4 shown, the present invention also provides a dexterous hand, which includes the compliant lateral swing mechanism 100 of the first embodiment, and further includes a palm body 200 and a finger mechanism 300.

[0082] Since the dexterous hand includes the compliant lateral swing mechanism 100, the beneficial effects of the dexterous hand can refer to those of the compliant lateral swing mechanism 100.

[0083] The finger mechanism 300 is used to simulate a finger, and each joint of the finger mechanism 300 can be driven by a motor to achieve bending, which will not be elaborated here.

[0084] The above embodiments are only used to illustrate the technical ideas and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The scope of the patent adoption of the present invention cannot be limited only by this embodiment, that is, any equivalent changes or modifications made according to the spirit disclosed by the present invention still fall within the scope of the patent of the present invention.

Claims

1. Compliant side-sway mechanism (100), characterized in that, Comprising: A mating pair (110) configured to be connected to the finger mechanism (300); A planar cam (120) configured to move on the palm body (200), at least one set of through-holes (121) being formed in the planar cam (120), the number of through-holes (121) in each set being two, and an elastic plate (122) being formed between the two through-holes (121) in each set; The elastic plate (122) is engaged by the mating pair (110), and during the movement of the planar cam (120), the elastic plate (122) moves relative to the mating pair (110), thereby driving the finger mechanism (300) to swing laterally, and the elastic characteristics of the elastic plate (122) are utilized to provide compliant lateral swing for the finger mechanism (300).

2. The compliant side-sway mechanism (100) according to claim 1, characterized in that, The mating pair (110) comprises: A connection end (111) configured to connect to the finger mechanism (300); An engaging end (112) including two engaging blocks (112a) and a slot (112b) located between the two engaging blocks (112a); The elastic plate (122) is slidably disposed in the slot (112b), and the two engaging blocks (112a) are respectively located in the through-holes (121) on both sides of the elastic plate (122).

3. The compliant side-sway mechanism (100) according to claim 1, characterized in that, The contour of the through-hole (121) includes a straight surface (121a) and a curved surface (121b) connected end to end in sequence, and the elastic plate (122) is formed between the straight surfaces (121a) of the two through-holes (121).

4. The compliant side-sway mechanism (100) according to claim 1, characterized in that, The width of the through-hole (121) gradually decreases from the middle in the length direction of the elastic plate (122) to both ends in the length direction of the elastic plate (122).

5. The compliant side-sway mechanism (100) according to claim 1, wherein, A guiding assembly (140) is disposed between the planar cam (120) and the palm body (200).

6. The compliant side-sway mechanism (100) according to claim 5, characterized in that, The non-elastically deformed elastic plate (122) is inclined with respect to the guiding direction of the guiding assembly (140).

7. The compliant side-sway mechanism (100) according to claim 1, characterized in that, Further comprising: A lateral swing power member (130) drivingly connected to the planar cam (120).

8. The compliant side-sway mechanism (100) according to claim 1, characterized in that, The finger mechanism (300) is disposed on the palm body (200) in a manner of rotating about a rotation axis (310), and the mating pair (110) and the through-holes (121) of the compliant lateral swing mechanism (100) are located below the rotation axis (310).

9. The compliant side-sway mechanism (100) according to claim 1, wherein, The planar cam (120) is located between the palm body (200) and the finger mechanism (300).

10. A dexterous hand, characterized in that, Comprising the compliant lateral swing mechanism (100) according to any one of claims 1 to 9, and further comprising a palm body (200) and a finger mechanism (300).

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