Compliant side swing mechanism and dexterous hand

Abstract

The application provides a compliant side swing mechanism and a dexterous hand, wherein the compliant side swing mechanism comprises a matching pair and a plane cam, the matching pair is used for being connected on a finger mechanism, the plane cam is used for moving on a palm body, at least one group of openings are arranged on the plane cam, the number of each group of the openings is two, and an elastic plate is formed between the two openings of each group; the elastic plate is clamped by the matching pair, the elastic plate moves relative to the matching pair in the moving process of the plane cam, thereby driving the finger mechanism to swing, and the elastic property of the elastic plate is used for providing the compliant side swing of the finger mechanism, and the size of the side swing mechanism is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of robotics, and more particularly to a compliant lateral swing mechanism and a dexterous hand. Background Technology

[0002] As the end effector of a robot, the core function of a robotic hand is to simulate human hand movements to perform tasks such as grasping and manipulating tools. Dexterous hands, as a more advanced form of robotic hand, are structurally closer to the human hand, with each finger typically equipped with multiple degrees of freedom. Among these, bending and lateral swing are key, giving them greater flexibility in manipulation.

[0003] Most current dexterity hand designs focus on bending freedom, with rigid structures used in their transmission mechanisms. While this design is stable in simple operational scenarios, its functionality is relatively limited. Only a small number of dexterity hands possess lateral swing freedom, and these often employ underactuated mechanisms, using rigid components such as gears and linkages to achieve multi-finger lateral swing coordination. However, achieving independent and smooth passive lateral swing motion for each finger remains a major technical bottleneck in current dexterity hand design.

[0004] In real-world operating environments, dexterous hands inevitably come into contact with their surroundings. Since most existing designs lack passive compliance, they are easily damaged upon impact, which not only increases maintenance costs but also limits the application range of dexterous hands in complex and unknown environments.

[0005] For example, patent document CN118636177A discloses a design scheme for a dexterous hand side-swing mechanism. This scheme uses a combination of a single drive component and a coupled rigid linkage mechanism to achieve synchronous side-swing motion of multiple finger joints. Although there is a breakthrough 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 this invention is to address the shortcomings of existing technologies by providing a compliant lateral swing mechanism and a dexterous hand.

[0007] To achieve the above objectives, the present invention provides the following technical solution: Compliant lateral sway mechanism, including: A mating pair, which is used for connection to a finger mechanism; A planar cam is used to move on the palm body. The planar cam has at least one set of openings, and each set of openings has two openings. An elastic plate is formed between the two openings in each set. The elastic plate is engaged with 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 sway sideways and using the elastic properties of the elastic plate to provide compliant swaying for the finger mechanism.

[0008] In a preferred embodiment, the mating pair includes: The connecting end is used to connect the finger mechanism; The engaging end includes two engaging blocks and a slot located between the two engaging blocks; The elastic plate is slidably disposed within the slot, and the two locking blocks are respectively located within the openings on both sides of the elastic plate.

[0009] In a preferred embodiment, the outline of the opening 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 openings.

[0010] In a preferred embodiment, the width of the opening gradually decreases from the middle of the elastic plate along its length to both ends of the elastic plate along its length.

[0011] In a preferred embodiment, a guide assembly is provided between the planar cam and the palm body.

[0012] In a preferred embodiment, the elastic plate, which is not elastically deformed, is inclined relative to the guiding direction of the guiding assembly.

[0013] In a preferred embodiment, the guide component includes: A guide groove is formed on the palm body, and the length direction of the guide groove defines the guiding direction of the guide component; A guide post is disposed on the planar cam and slides within the guide groove.

[0014] As a preferred embodiment, it also includes: A lateral swing force component is connected to the planar cam drive.

[0015] In a preferred embodiment, the finger mechanism is mounted on the palm body in a manner that allows it to rotate about a rotation axis, and the mating parts and openings of the compliant lateral swing mechanism are located below the rotation axis.

[0016] In a preferred embodiment, the planar cam of the compliant lateral swing mechanism is located between the palm body and the finger mechanism.

[0017] The present invention also provides a dexterous hand, including the compliant lateral swing mechanism of the above embodiments, and further including a palm body and a finger mechanism.

[0018] Compared with existing technologies, this technical solution has the following advantages: Through the design of the mating pair and the elastic plate, not only can the lateral swinging motion of the finger mechanism be realized, but each finger mechanism can also be given independent compliance characteristics, which improves the safety of the interaction between the dexterous hand and the environment.

[0019] The swing motion and compliance characteristics of multiple finger mechanisms can be integrated into a single structure, reducing the number of parts and structural complexity, effectively reducing the size of the side swing mechanism, and contributing to the miniaturization and weight reduction of dexterous hands. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the compliant lateral swing mechanism described in this invention; Figure 2 for Figure 1 Sectional view along the AA direction; Figure 3 This is a schematic diagram of the assembly of the mating pair and the planar cam described in this invention; Figure 4 This is a schematic diagram of the structure of the dexterous hand described in this invention.

[0021] In the diagram: 100 Compliant side-swing mechanism, 110 Mating pair, 111 Connecting 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 force component, 140 Guide assembly, 141 Guide groove, 142 Guide post, 150 Snap ring, 200 Hand body, 300 Finger mechanism, 310 Rotating shaft. Detailed Implementation

[0022] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0023] First Embodiment like Figure 1 As shown, the present invention provides a compliant lateral sway mechanism 100, comprising: A mating pair 110 is used to connect to the finger mechanism 300; A planar cam 120 is used to move on the palm body 200. The planar cam 120 has at least one set of openings 121, and each set of openings 121 has two openings. An elastic plate 122 is formed between the two openings 121 in each set. The elastic plate 122 is engaged with 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 sway sideways, and using the elastic properties of the elastic plate 122 to provide the finger mechanism 300 with compliant swaying.

[0024] The mating pair 110 is connected to the finger mechanism 300, so that the mating pair 110 engages with the elastic plate 122 on the planar cam 120. Simultaneously, the elastic plate 122 can move relative to the mating pair 110. Thus, when an external force drives the planar cam 120 to move on the palm body 200, not only is the left and right lateral swing of the finger mechanism 300 achieved, but the elastic properties of the elastic plate 122 also provide compliance during the lateral swing, adapting to different working environments and task requirements. For example, when the finger mechanism 300 encounters an obstacle during lateral swing, the elastic plate 122 will elastically deform, absorbing some of the collision energy, thereby reducing the impact on the finger mechanism 300 and the grasped object, making the lateral swing more stable and gentle. This mechanism mainly consists of the mating pair 110, the planar cam 120, and other components. Its structure is relatively simple, occupies little space, and is easy to install and arrange in limited spaces such as the palm of the hand.

[0025] like Figures 1 to 3 As shown, the mating pair 110 is fixed to the finger mechanism 300. Specifically, a retaining ring 150 is sleeved on the finger mechanism 300, and the mating pair 110 can be connected to the retaining ring 150 to fix the mating pair 110 to the finger mechanism 300. The mating pair 110 can be integrally connected to the retaining ring 150. Thus, during the assembly of the mating pair 110 and the finger mechanism 300, simply insert the lower end of the finger mechanism 300 into the retaining ring 150 of the mating pair 110 until the retaining ring 150 is tightly fitted with the finger mechanism 300. Alternatively, a screw can be passed through the retaining ring 150 and screwed onto the finger mechanism 300 for enhanced fixation.

[0026] refer to Figure 2 The mating pair 110 includes: Connection end 111, the connection end 111 is used to connect the finger mechanism 300; The engaging end 112 includes two engaging blocks 112a and a slot 112b located between the two engaging blocks 112a; The elastic plate 122 is slidably disposed within the slot 112b, and the two locking blocks 112a are respectively located within the openings 121 on both sides of the elastic plate 122.

[0027] The connecting end 111 and the engaging end 112 are located at the two ends of the length direction of the mating pair 110. 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.

[0028] The cross-section of the mating pair 110 can be circular, square, or the like. Taking the circular cross-section of the mating pair 110 as an example, the cross-sections of the two engaging blocks 112a are each semi-circular.

[0029] 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 within the slot 112b with the planar cam 120.

[0030] like Figure 1 and Figure 3 As 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. One side of the planar cam 120 in the thickness direction is in contact with the palm body 200, while the other side maintains a small gap with the finger mechanism 300, allowing the planar cam 120 to slide on the palm body 200. Simultaneously, the mating pair 110 is perpendicular to the planar cam 120. By rationally designing the thickness of the planar cam 120, its mating method with the palm body 200 and the finger mechanism 300, and the layout of the mating pair 110, the space occupied by the compliant lateral swing mechanism 100 within the dexterous hand is effectively reduced.

[0031] refer to Figure 1 The planar cam 120 has at least one set of openings 121, with each set of openings 121 corresponding 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, but not every finger requires the same lateral swing drive configuration. Depending on actual needs, openings 121 and mating pairs 110 can be selectively provided for some finger mechanisms 300.

[0032] like Figure 1 and Figure 3As shown, the finger mechanism 300 is mounted on the palm body 200 in a manner that allows it to rotate about a rotation axis 310, which is perpendicular to the palm body 200. In this embodiment, the rotation axis 310 is fixed to 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 (laterally) about the vertical direction of the palm body 200.

[0033] The mating pair 110 of the compliant lateral swing mechanism 100 and its corresponding opening 121 are located below the rotating shaft 310. This layout makes full use of the vertical space of the palm body 200, avoids interference with other components, and also provides sufficient space for the movement of the planar cam 120.

[0034] When the planar cam 120 moves up and down relative to the palm body 200, the elastic plate 122 of the planar cam 120 moves within the slot 112b of the mating pair 110 because the elastic plate 122 is tilted relative to the vertical direction. 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 lateral swinging motion around the rotation axis 310. That is, the linear motion of the planar cam 120 is converted into the lateral swinging motion of the finger mechanism 300. Since the elastic plate 122 is elastic, when the finger mechanism 300 is subjected to an external force in the left and right direction, the elastic plate 122 undergoes elastic deformation, realizing the smooth lateral swinging function of the finger mechanism 300.

[0035] The tilt angle of the elastic plate 122 relative to the vertical direction and the length of the elastic plate 122 determine the lateral swing angle of the finger mechanism 300. (Reference) Figure 1 The little finger, ring finger, middle finger, and index finger are arranged from left to right.

[0036] Taking the little finger as an example, the elastic plate 122 tilts 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.

[0037] Taking the ring finger as an example, it is the same as the little finger. The elastic plate 122 is tilted to the right, but the tilt angle of the elastic plate 122 corresponding to the ring finger is smaller than the tilt angle of the elastic plate 122 corresponding to the little finger.

[0038] Taking the index finger as an example, the elastic plate 122 tilts 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.

[0039] It should be noted that the number of openings 121 on the planar cam 120 can be equal to the number of finger mechanisms 300, and the tilt angle of the elastic plate 122 corresponding to each finger mechanism 300 is different, so that multiple finger mechanisms 300 can swing sideways at the same time with different swing angles. Therefore, the swinging motion of each finger mechanism 300 is independent and selectable, which greatly enhances the flexibility and adaptability of dexterous hand grasping.

[0040] refer to Figure 1 and Figure 3 Each group of openings 121 comprises two openings, with an elastic plate 122 formed between the two openings 121 in each group. When the elastic plate 122 is in an inelastic deformation state, the two openings 121 in each group are symmetrically arranged with respect to the elastic plate 122. The outline of each opening 121 includes a straight surface 121a and a curved surface 121b connected end-to-end in sequence. The straight surfaces 121a of the two openings 121 face inwards, and the elastic plate 122 is formed between the straight surfaces 121a of the two openings 121, while the curved surface 121b faces outwards.

[0041] Therefore, it can be seen that the elastic plate 122 in its non-elastic deformation state is linear and is engaged within the locking slot 112b of the mating pair 110. The planar cam 120 is made of stainless steel or similar materials, and the elastic plate 122 is relatively thin, thus the elastic plate 122 has elastic deformation capability.

[0042] The outline of the opening 121 defines the compliance 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 elastic plate 122's ability to deform in the direction of the curved surface 121b. In this embodiment, the width of the opening 121 gradually decreases from the middle of the elastic plate 122's length direction to both ends of the elastic plate 122, allowing the elastic plate 122 to have different deformation capabilities at different length positions, thereby achieving gradient compliance. During the lateral swing of the finger mechanism 300, the middle portion of the elastic plate 122 can provide greater compliance to buffer external impacts.

[0043] like Figure 1As shown, a guide assembly 140 is provided between the planar cam 120 and the palm body 200 to provide movement guidance for the planar cam 120 relative to the palm body 200. The guide direction of the guide assembly 140 is vertical; therefore, the elastic plate 122, which is not elastically deformed, is inclined relative to the guide direction of the guide assembly 140.

[0044] refer to Figure 1 The guide assembly 140 includes: A guide groove 141 is formed on the palm body 200, and the length direction of the guide groove 141 defines the guiding direction of the guide assembly 140. Guide post 142 is disposed on the planar cam 120 and slides within the guide groove 141.

[0045] The length of the guide groove 141 defines the guiding direction of the guide assembly 140 as vertical. The guide post 142 slides within the guide groove 141, thereby providing precise movement guidance for the planar cam 120 relative to the palm body 200, ensuring that the planar cam 120 can only move up and down in a vertical direction. At the same time, the length of the guide groove 141 limits the distance the planar cam 120 can move up and down, preventing the planar cam 120 from moving excessively and deviating from its normal operating range.

[0046] The number of guide components 140 can be multiple, further improving the motion stability and guiding accuracy of the planar cam 120. In this embodiment, one guide component 140 is provided between two adjacent finger mechanisms 300.

[0047] Continue to refer to Figure 1 Because there is a height difference between the mating pairs 110 of the multiple finger mechanisms 300, the planar cam 120 is set at an angle to compensate for the height difference between the mating pairs 110. Similarly, there is also a height difference between the multiple guide components 140.

[0048] like Figure 1 As shown, the compliant lateral sway mechanism 100 further includes: Side swing force member 130, which is connected to the planar cam 120 in a transmission manner.

[0049] The lateral swing force member 130 can be a small motor, fixed to the palm body 200 and 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 also contributes to the overall compactness of the structure, conforming to the design trend of miniaturization and lightweight dexterity. The rotation of the lateral swing force member 130 is converted into the up-and-down movement of the planar cam 120. For example, if the lateral swing force member 130 rotates clockwise, the planar cam 120 moves downward; if the lateral swing force member 130 rotates counterclockwise, the planar cam 120 moves upward.

[0050] The lateral swing force member 130 can be connected to the planar cam 120 via gears, racks, etc. Different reduction ratios can be designed according to the parameters of the gears, racks, etc. 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, thereby realizing the amplification function of the driving force and ensuring that the planar cam 120 can overcome various resistances and stably drive the finger mechanism 300 to swing sideways.

[0051] The number of the side swing force member 130 is one, which drives the planar cam 120 to move up and down, thereby driving multiple finger mechanisms 300 to swing sideways. This avoids the design of each finger mechanism 300 corresponding to a power source, reduces the spatial size of the compliant side swing mechanism 100, and thus achieves a more compact structural design for the dexterous hand.

[0052] It is worth noting that, since the elastic plate 122 has elastic deformation capability, the finger mechanism 300 still has compliant capability when subjected to external force even when the side swing force member 130 does not rotate (i.e., locked state).

[0053] The working steps of the compliant lateral sway mechanism 100 are as follows: The rotation of the lateral swing force member 130 drives the planar cam 120 to move vertically under the guidance of the guide assembly 140. At this time, the elastic plate 122 of the planar cam 120 and the locking slot 112b of the mating pair 110 move relative to each other, causing each of the finger mechanisms 300 to laterally swing. When a finger mechanism 300 encounters external resistance, the elastic plate 122 bends and deforms, absorbing some energy, thus making the lateral swing motion smoother.

[0054] In summary, through the cooperative design of the mating pair 110 and the elastic plate 122, not only is the lateral swing motion of the finger mechanism 300 realized, but each finger mechanism 300 is also endowed with independent compliance characteristics, improving the safety of the dexterous hand's interaction with the environment. The swing motion and compliance characteristics of multiple finger mechanisms 300 can be integrated into a single structure, and motion transmission can be achieved using a principle similar to cam transmission, that is, the linear motion of the planar cam 120 is converted into the lateral swing motion of the finger mechanism 300. Compared with traditional rigid linkages and gear transmission methods, the integrated design reduces the number of parts and structural complexity, effectively reducing the size of the lateral swing mechanism, which is beneficial for the miniaturization and weight reduction of the dexterous hand.

[0055] Second Embodiment like Figure 4 As shown, the present invention also provides a dexterous hand, including the compliant lateral swing mechanism 100 of the first embodiment, and also including a palm body 200 and a finger mechanism 300.

[0056] Since the dexterous hand includes a compliant lateral swing mechanism 100, the beneficial effects of the dexterous hand can be seen from the compliant lateral swing mechanism 100.

[0057] The finger mechanism 300 is used to simulate a finger. Each joint of the finger mechanism 300 can be driven by a motor to achieve bending, which will not be described in detail here.

[0058] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. 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 patent application of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A dexterous hand, characterized in that, It includes a compliant lateral swing mechanism (100), a palm body (200), and a finger mechanism (300), wherein the compliant lateral swing mechanism (100) includes: A mating pair (110) is used for connection to the finger mechanism (300); A planar cam (120) is used to move on the palm body (200). The planar cam (120) has at least one set of openings (121), and each set of openings (121) has two openings. An elastic plate (122) is formed between the two openings (121) in each set. The elastic plate (122) is engaged with 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 sway sideways, and using the elastic properties of the elastic plate (122) to provide compliant swaying for the finger mechanism (300). The mating pair (110) includes: Connecting end (111), the connecting end (111) is used to connect the finger mechanism (300). The engaging end (112) includes 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 locking blocks (112a) are respectively located in the openings (121) on both sides of the elastic plate (122); The outline of the opening (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 openings (121). The width of the opening (121) gradually decreases from the middle of the elastic plate (122) along its length to both ends of the elastic plate (122) along its length. A guide assembly (140) is provided between the planar cam (120) and the palm body (200). The elastic plate (122) without elastic deformation is inclined relative to the guiding direction of the guide assembly (140).

2. The dexterous hand as described in claim 1, characterized in that, Also includes: A side-swing force member (130) is connected to the planar cam (120) via a transmission connection.

3. The dexterous hand as described in claim 1, characterized in that, The finger mechanism (300) is mounted on the palm body (200) in a manner that it rotates about the rotation axis (310). The mating pair (110) and opening (121) of the compliant lateral swing mechanism (100) are located below the rotation axis (310), which is fixed on the palm body (200).

4. The dexterous hand as described in claim 1, characterized in that, The planar cam (120) is located between the palm body (200) and the finger mechanism (300).

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