Robotic flexible joint

Abstract

The present application relates to a kind of robot flexible joints, including two fixed seats, multiple soft actuators and damper.Multiple soft actuators are located between two fixed seats, and the two ends of each soft actuator are respectively connected at the edge of two fixed seats;Damper is located between multiple soft actuators, and the two ends of damper are respectively connected with two fixed seats.The above-mentioned robot flexible joint can realize the one-way movement or combined movement of robot in multiple degrees of freedom.Because soft actuator is usually made of soft material such as rubber, therefore the rigidity of soft actuator is largely dependent on the actual state of soft actuator, the robot flexible joint is provided with damper between two fixed seats, which enhances the anti-interference ability and stability of structure, and the strength is higher, so that robot flexible joint can play better movement and control effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot technology, in particular to a robot flexible joint. BACKGROUND

[0002] A robot is an automatic machine, which is different from the machine in that the machine has some intelligent capabilities similar to humans or living beings, such as perception, planning, action, and cooperation, and is an automatic machine with high flexibility. Robots can assist or even replace humans to complete dangerous, heavy, and complex work, improve work efficiency and quality, and serve human life, and expand and extend the range of human activities and capabilities.

[0003] Most of the robots on the market are rigid robots. Since the rigid robot usually drives the joint by using a motor, the advantages are strong load capacity, high repeatability, and high positioning accuracy. However, if multiple single-degree-of-freedom joints are assembled or more motors are used for control to achieve multi-degree-of-freedom motion, the complexity of the system is increased, and the volume and weight are greatly increased.

[0004] With the emergence and development of soft robot technology, soft robots are used as end effectors to replace rigid robot end grippers for clamping targets and have been widely applied. However, when flexible robots are applied to joints, the more degrees of freedom of the flexible joint, the more difficult it is to guarantee the stability and strength, that is, the problem that the multi-degree-of-freedom of the flexible joint cannot be considered together with the stability and strength restricts the development of the flexible joint. SUMMARY

[0005] Therefore, it is necessary to provide a robot flexible joint that can realize one-way motion or combined motion of a robot in multiple degrees of freedom and has high stability and strength.

[0006] A robot flexible joint comprises:

[0007] two fixed seats;

[0008] a plurality of soft actuators located between the two fixed seats, and two ends of each soft actuator are connected to the edges of the two fixed seats, respectively;

[0009] a damper located between the plurality of soft actuators, and two ends of the damper are connected to the two fixed seats, respectively.

[0010] In one embodiment, the soft actuators are inclined, and the distance from the two ends of the soft actuators to the center of the two fixed seats connected thereto is equal.

[0011] In one of the embodiments, two adjacent soft actuators are symmetrical, and the symmetry plane is the plane passing through the centers of the two fixing bases.

[0012] In one of the embodiments, the plurality of soft actuators are connected in sequence and form a closed connection.

[0013] In one of the embodiments, the plurality of soft actuators form a plurality of angles after being connected, and the angles are equal.

[0014] In one of the embodiments, the two ends of the damper are connected to the centers of the two fixing bases, and two adjacent soft actuators are symmetrical with respect to the axis of the damper.

[0015] In one of the embodiments, the fixing base is arranged in a ring structure, the inner ring of the fixing base is fixed with a mounting frame, and the end of the damper is mounted on the mounting frame.

[0016] In one of the embodiments, the surface of the fixing base is provided with a plurality of pairs of first positioning screws, and the plurality of pairs of first positioning screws are distributed along the outer periphery of the fixing base and are opposite to the plurality of pairs of soft actuators.

[0017] In one of the embodiments, the end of the soft actuator is movably mounted with a first threaded sleeve, and the first threaded sleeve is mounted on the first positioning screw.

[0018] In one of the embodiments, the end of the soft actuator is fixed with a ball head, and the ball head is movably clamped at the top end of the first threaded sleeve.

[0019] The above robot flexible joint can adjust the distance between the two fixing bases by arranging a plurality of soft actuators along the edges of the two fixing bases. During use, the soft actuators can be driven at different positions to control the stretching and contraction of the soft actuators at different positions between the two fixing bases, thereby achieving multi-directional control of the joint rotation. The structure can realize one-way movement or combined movement of the robot in multiple degrees of freedom. Since the soft actuator is usually made of soft materials such as rubber, the rigidity of the soft actuator depends largely on the actual state of the soft actuator. The robot flexible joint can enhance the anti-interference ability and stability of the structure by arranging a damper between the two fixing bases, and has higher strength, so that the robot flexible joint can achieve better movement and control effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative work based on these drawings also belong to the protection scope of the present application.

[0021] Figure 1 A schematic view of a single structure of a robot flexible joint of the present application;

[0022] Figure 2 A schematic view of a combined structure of a robot flexible joint of the present application;

[0023] Figure 3 A schematic view of a fixed assembly of a robot flexible joint of the present application;

[0024] Figure 4 A schematic view of an execution assembly of a robot flexible joint of the present application;

[0025] Figure 5 A schematic view of a buffer assembly of a robot flexible joint of the present application.

[0026] Reference signs:

[0027] 110, fixed seat; 120, first positioning screw; 130, mounting frame; 210, first screw sleeve; 220, ball head; 230, soft actuator; 310, spherical seat; 320, second screw sleeve; 330, first elastic member; 340, second elastic member; 350, damper. DETAILED DESCRIPTION

[0028] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present application.

[0029] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly on the other component or there can be a middle component. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there can be a middle component. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the specification of the present application are only for the purpose of illustration, not for the only implementation.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0033] The following is combined with Figures 1-5 Describes the flexible joint of the robot of the present invention.

[0034] like Figure 1 and Figure 2 As shown, in one embodiment, a robot flexible joint includes two fixed seats 110, a plurality of soft actuators 230, and a damper 350; the plurality of soft actuators 230 are located between the two fixed seats 110, and the two ends of each soft actuator 230 are respectively connected to the edges of the two fixed seats 110; the damper 350 is located between the plurality of soft actuators 230, and the two ends of the damper 350 are respectively connected to the two fixed seats 110.

[0035] It should be noted that, as a joint mechanism, its main function is to connect the robot structure at the front and rear levels and change the motion state. Specifically, in this embodiment, the upper fixed seat 110 is used to connect with the structure at the next level, such as the end effector, etc., and the lower fixed seat 110 is used to connect with the mechanism at the previous level, such as the machine base, the insertion port of the robotic arm, etc. Both fixed seats 110 are plate-shaped structures with cross-sectional shapes that can be square, circular, or any other shape. They are made of rigid materials and manufactured by methods such as metal processing, injection molding, 3D printing, etc.

[0036] The aforementioned flexible robot joint, with multiple soft actuators 230 arranged along the edges of the two fixed seats 110, allows for adjustment of the distance between the two fixed seats 110. During use, by driving one or more soft actuators 230 at different positions, the distance between the two fixed seats 110 can be controlled, achieving multi-directional control of joint rotation. This structure enables the robot to perform unidirectional or combined movements in multiple degrees of freedom. Since the soft actuators 230 are typically made of soft materials such as rubber, their stiffness largely depends on their actual state (e.g., pneumatic soft actuators 230 have higher stiffness when the internal air pressure is high). This flexible robot joint, by incorporating a damper 350 between the two fixed seats 110, enhances the structure's anti-interference capability and stability, and increases its strength, allowing for better movement and control.

[0037] It should be noted that the soft actuator 230 located between the two fixed bases 110 typically uses an actuator with a telescopic action, such as a fluid-driven bladder actuator, a bellows, a stacked bag actuator, an origami-structure actuator, etc. Figure 1 and Figure 2 The middle one is an actuator in the form of a bellows. These actuators are usually made of flexible materials and corresponding processing and manufacturing processes. For example, plastic actuators are processed by injection molding and blow molding, silicone actuators are processed by mold casting, and thin sheet actuators such as TPU or composite fabrics can be processed by hot pressing, high frequency welding, etc.

[0038] In one embodiment, the software actuator 230 is tilted, and the two ends of the software actuator 230 are equidistant from the centers of the two corresponding fixed seats 110.

[0039] Specifically, since the soft actuator 230 is distributed along the edges of the two fixed seats 110, by setting the soft actuator 230 to an inclined state and making the distances from both ends of the soft actuator 230 to the centers of the two corresponding fixed seats 110 equal, the flexible joint structure is more regular, the stability is higher when adjusting the distance between the two fixed seats 110, and the calculation of the subsequent flexible joint adjustment angle is also faster.

[0040] Taking the airbag actuator as an example, each end of the airbag has a mounting structure, which is installed at the corresponding mounting position of the soft actuator 230 on the two fixed bases 110. When driving, the air inlet can be set in the middle of the actuator or at both ends, and the air passage is set inside the fixed base 110 or around the fixed base 110. During installation, the axial direction of the soft actuator 230 and the axial direction of the flexible joint need to be installed in a spatially intersecting manner, that is, the soft actuator 230 is tilted.

[0041] In one embodiment, two adjacent software actuators 230 are symmetrical, and the plane of symmetry is the plane passing through the center of the two fixed seats 110.

[0042] Specifically, by setting adjacent soft actuators 230 symmetrically, and with the symmetrical plane passing through the center of the two fixed seats 110, it can be known that the symmetrical plane is a radial tangent of the two fixed seats 110. At the same time, since the two ends of the multiple soft actuators 230 are connected to the edges of the two fixed seats 110, by driving the soft actuators 230 at different positions to generate extension and retraction movements, the flexible joint can realize unidirectional or combined movements in six degrees of freedom, such as translation in the three spatial directions x, y, and z and rotation along the three directions.

[0043] In one embodiment, multiple software actuators 230 are connected end-to-end in sequence to form a closed connection.

[0044] Specifically, the closed structure provides greater stability in actual use.

[0045] In one embodiment, the angles of the multiple included angles formed by the connection of multiple software actuators 230 are equal.

[0046] Specifically, if the axis of the flexible joint can be parallel to the axis of the soft actuator 230 when rotated clockwise by less than 90 degrees, the soft actuator 230 is installed at a positive angle; conversely, if it can be parallel to the axis of the soft actuator 230 when rotated counterclockwise by less than 90 degrees, the soft actuator 230 is installed at a negative angle. The soft actuators 230 installed at a positive angle always appear in pairs with those installed at a negative angle, forming a group. Therefore, the number of soft actuators 230 can be one or more groups, distributed between the two fixed seats 110.

[0047] In one embodiment, the two ends of the damper 350 are respectively connected to the center of the two fixed seats 110, and the two adjacent soft actuators 230 have two other adjacent soft actuators 230 that are symmetrical about the axis of the damper 350.

[0048] It should be noted that threaded holes, pin holes, and other auxiliary installation and fixing structures can be provided on the fixed base 110 as needed. Furthermore, two or more sets of flexible joints can be used, and the upper and lower fixed bases 110 of the two flexible joints can be connected and assembled sequentially into a complete set of flexible joints (or a six-degree-of-freedom motion system), thereby increasing the deformation in each degree of freedom, such as... Figure 2 It is an integral structure consisting of three sets of flexible joints connected together, and each set of flexible joints can also be at a first angle around the overall axis, increasing the range of motion.

[0049] like Figure 3 As shown, in one embodiment, the fixing base 110 is arranged in a ring structure, and the mounting bracket 130 is fixed on the inner ring of the fixing base 110. The end of the damper 350 is mounted on the mounting bracket 130.

[0050] The surface of the fixed base 110 is provided with multiple pairs of first positioning screws 120. The multiple pairs of first positioning screws 120 are distributed along the outer periphery of the fixed base 110 and are respectively opposite to multiple pairs of soft actuators 230.

[0051] Specifically, the first positioning screw 120 is used to position the soft actuator 230, and the number of the first positioning screws 120 on the surface of the fixed base 110 is at least four pairs, so as to ensure that at least four pairs of soft actuators 230 can be installed on the fixed base 110.

[0052] like Figure 4 As shown, in one embodiment, a first threaded sleeve 210 is movably mounted on the end of the soft actuator 230, and the first threaded sleeve 210 is mounted on the first positioning screw 120. A ball head 220 is fixed to the end of the soft actuator 230, and the ball head 220 is movably engaged with the top end of the first threaded sleeve 210.

[0053] Specifically, the ball head 220 is used to connect the first threaded sleeve 210 and the soft actuator 230. When installing the soft actuator 230, the first threaded sleeve 210 can be directly screwed onto the first positioning screw 120. During the installation process, the soft actuator 230 remains in an inconvenient position, making the installation convenient and stable.

[0054] like Figure 5 As shown, in one embodiment, the robot flexible joint further includes a ball seat 310, which is movably snapped onto the mounting bracket 130, and one end of the damper 350 is connected to the ball seat 310.

[0055] Specifically, when the flexible joint deflects, the soft actuator 230 between the two fixed seats 110 operates to drive it. Since the relative distance between the two fixed seats 110 is limited by the damper 350, the fixed seat 110 and the spherical seat 310 installed in the fixed seat 110 rotate relative to each other, thereby realizing the rotation of the flexible joint.

[0056] In one embodiment, the spherical seat 310 is hollow inside and has an opening. The second threaded sleeve 320 is disposed inside the spherical seat 310, and one end of the second threaded sleeve 320 facing the inside of the spherical seat 310 is elastically connected to the spherical seat 310 through a second elastic member 340. The sidewall of the second threaded sleeve 320 is elastically connected to the spherical seat 310 through a first elastic member 330. One end of the damper 350 is threadedly installed inside the second threaded sleeve 320.

[0057] Specifically, when the two ends of the damper 350 are respectively installed in the two second threaded sleeves 320, if the flexible joint is subjected to an external force in a non-axial direction, the multiple first elastic elements 330 connecting the second threaded sleeves 320 and the ball seat 310 will expand and contract to different degrees, thereby buffering the force on the flexible joint and reducing vibration. If the flexible joint is subjected to an external force in the axial direction, the second elastic element 340 connecting the second threaded sleeves 320 and the ball seat 310 will deform, thereby buffering the force on the flexible joint and preventing damage to the components inside the flexible joint.

[0058] It should be noted that because the damper 350 has a large damping capacity, it can provide buffering and vibration reduction effects. Furthermore, the damping magnitude of the damper 350 is adjustable, thus controlling the driving force required during actuation. Introducing the damper 350 into the flexible joint enhances the joint's anti-interference capability and stability, leading to better control. The damper 350 does not require active movement; after installation in its corresponding position, it passively moves with the actuation of the soft actuator 230, thereby achieving its adjustment function. Since the joint can achieve translation in the x, y, and z directions, rotation around three axes, and various composite movements, the damper 350 is typically connected to the upper and lower fixed seats 110 at both ends via ball joints, universal joints, or other suitable structures during installation. This allows the damper 350 to adapt to the changes in shape and position as the flexible joint moves.

[0059] In one embodiment, the damper 350 can be installed at the central axis of the flexible joint, or multiple dampers can be used and evenly distributed in a circular manner on the fixed base 110.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A flexible joint for robots, characterized in that, include: Two fixed seats; Multiple soft actuators are located between the two fixed bases, and the two ends of each soft actuator are respectively connected to the edges of the two fixed bases; A damper is located between the plurality of said soft actuators, and the two ends of the damper are respectively connected to the two said fixed seats; The soft actuator is tilted, and the distances from both ends of the soft actuator to the centers of the two corresponding fixed seats are equal. The two adjacent software actuators are symmetrical, and the plane of symmetry is the plane passing through the center of the two fixed seats; The multiple software actuators are connected end to end in sequence to form a closed connection; The angles formed by the connection of the multiple software actuators are equal; The two ends of the damper are respectively connected to the center of the two fixed seats, and the two adjacent soft actuators have two other adjacent soft actuators that are symmetrical about the axis of the damper; The fixed base is arranged in a ring structure, and a mounting bracket is fixed to the inner ring of the fixed base. The end of the damper is mounted on the mounting bracket. The surface of the fixed base is provided with multiple pairs of first positioning screws, which are distributed along the outer circumference of the fixed base and are respectively opposite to multiple pairs of soft actuators; The end of the soft actuator is movably fitted with a first threaded sleeve, which is mounted on the first positioning screw. The end of the soft actuator is fixed with a ball head, which is movably engaged with the top of the first threaded sleeve; The robot's flexible joint also includes a spherical seat, which is movably attached to the mounting frame, and one end of the damper is connected to the spherical seat; The spherical seat is hollow inside and has an opening. The second threaded sleeve is disposed inside the spherical seat, and the end of the second threaded sleeve facing the inside of the spherical seat is elastically connected to the spherical seat through the second elastic element. The side wall of the second threaded sleeve is elastically connected to the spherical seat through the first elastic element. One end of the damper is threadedly installed inside the second threaded sleeve.

Images