A variable stiffness flexible manipulator for adaptive grasping in extreme environments

Abstract

This invention relates to a variable stiffness flexible robotic hand for adaptive grasping in extreme environments. The hand includes a flexible finger, which comprises a finger base, a fingertip block, multiple tension springs, and multiple compression spring assemblies. The tension springs are respectively disposed on both sides of the finger base and on both sides of the fingertip block. The ends of the tension springs on the same side are connected to one side of the finger base and the fingertip block, respectively. The multiple compression spring assemblies are disposed between the finger base and the fingertip block, and their ends are connected to the tension springs on both sides. This invention exhibits enhanced durability in extreme environments and possesses variable stiffness capability, enabling adaptive grasping.

Description

Technical Field

[0001] This invention relates to a variable stiffness flexible manipulator for adaptive grasping in extreme environments, belonging to the field of manipulator technology. Background Technology

[0002] With the continuous development of materials science, artificial intelligence, and robotics, the design of robotic hands has become increasingly diversified, and their grasping performance has gradually improved. Based on the stiffness of their mechanical fingers, robotic hands can be divided into rigid robotic hands and flexible robotic hands. Compared to rigid robotic hands, flexible robotic hands are more flexible, better able to adapt to complex and irregular object shapes, and reduce the risk of damage during interaction with objects. Currently, flexible robotic hands are widely used in robotics, medical, and industrial automation fields.

[0003] To enhance the applicability of flexible robotic arms to various grasping tasks, some flexible robotic arms possess variable stiffness capabilities. Variable stiffness flexible robotic arms can actively adjust the stiffness of their structure, exhibiting flexibility to adapt to complex shapes and reduce impact when needed for the task, and increasing structural stiffness when rigid support is required, thereby enhancing operational stability and improving control precision.

[0004] Flexible robotic arms typically utilize flexible materials, such as silicone and rubber, which are highly elastic. These materials possess excellent flexibility, allowing the robotic fingers to deform upon contact with objects, achieving an adaptive envelope effect and thus better grasping irregularly shaped objects. However, these flexible materials will fail in some extreme environments. For example, they are prone to brittle fracture at extremely low temperatures, melting at extremely high temperatures, and corrosion in strong acid or alkali environments. Currently, the field of robotic arms lacks corresponding flexible robotic arm solutions to adapt to these extreme environments.

[0005] Therefore, a new variable stiffness flexible manipulator is needed to solve the problems existing in the above-mentioned technologies, especially the problem that existing flexible manipulator materials are prone to failure in extreme environments. Summary of the Invention

[0006] This invention provides a variable stiffness flexible manipulator for adaptive grasping in extreme environments, aiming to solve at least one of the technical problems existing in the prior art. Therefore, the variable stiffness flexible manipulator for adaptive grasping in extreme environments proposed in this invention can improve the overall dynamic performance of the robot.

[0007] The technical solution of the present invention relates to a variable stiffness flexible manipulator, comprising: a flexible finger, the flexible finger including a finger base, a fingertip block, multiple tension springs and multiple compression spring assemblies, the multiple tension springs being respectively disposed on both sides of the finger base and the multiple tension springs being respectively disposed on both sides of the fingertip block, the two ends of the tension springs on the same side being respectively connected to one side of the finger base and the fingertip block; the multiple compression spring assemblies being disposed between the finger base and the fingertip block, the two ends of the multiple compression spring assemblies being respectively connected to the tension springs on both sides.

[0008] Furthermore, the tension spring is made of spring steel and stainless steel; the compression spring assembly is also made of spring steel and stainless steel.

[0009] Furthermore, it also includes a drive assembly and a transmission mechanism. The drive assembly includes a drive motor, the output shaft of which is connected to the transmission mechanism, which is connected to the flexible finger.

[0010] Furthermore, the drive assembly includes a drive housing cover, a drive housing body, and a drive housing base. The drive housing cover and the drive housing base respectively cover both ends of the drive housing body. The drive motor is disposed in the drive housing body, and the output shaft of the drive motor is connected to the transmission mechanism.

[0011] Furthermore, the transmission mechanism includes a trapezoidal lead screw, a lead screw nut, and a sliding connecting plate. The trapezoidal lead screw is threadedly connected to the lead screw nut, the sliding connecting plate is fixedly connected to the lead screw nut, and the trapezoidal lead screw is fixedly connected to the output shaft of the drive motor.

[0012] Furthermore, the transmission mechanism includes a finger mounting base, a movable connecting rod, and a connecting rod. The finger mounting base is fixedly connected to the flexible finger. Both ends of the movable connecting rod are rotatably connected to the finger mounting base and the sliding connecting plate, respectively. One end of the connecting rod is fixedly connected to the drive box cover, and the other end of the connecting rod is rotatably connected to the finger mounting base.

[0013] Furthermore, the transmission mechanism also includes a limiting aluminum column, which is rotatably connected to the finger mounting base. The limiting aluminum column is located on the outside of the connecting rod and is allowed to abut against the connecting rod.

[0014] Furthermore, the compression spring assembly includes a fin compression spring, a fin corner joint, a fin pressure block, and a clamping screw. The end of the fin compression spring is connected to the fin corner joint. The fin corner joint and the fin pressure block are respectively disposed on the inner and outer sides of the tension spring. The clamping screw passes through the fin corner joint and the fin pressure block to clamp the tension spring located in the middle.

[0015] Furthermore, multiple fin compression springs are provided, and the multiple fin compression springs are divided into multiple groups. The multiple groups of fin compression springs are arranged in layers between the finger base and the fingertip block.

[0016] Furthermore, the fin plate corner joint block and the fin plate pressing block are both provided with fin plate semi-circular grooves on their contact surfaces that contact the tension spring; when the fin plate corner joint block and the fin plate pressing block are connected, the two fin plate semi-circular grooves form a fin plate circular groove, and the tension spring passes through the fin plate circular groove.

[0017] The beneficial effects of this invention are as follows.

[0018] The variable stiffness flexible manipulator for adaptive grasping in extreme environments according to embodiments of the present invention features flexible fingers whose flexible parts are mainly composed of tension springs and compression springs. The flexible fingers are made of spring steel and stainless steel, which offer greater durability in extreme environments compared to commonly used flexible materials in existing flexible fingers. Simultaneously, this flexible manipulator possesses variable stiffness capability, allowing it to actively adjust the stiffness of the fingers according to the needs of the operation or grasping task, thus achieving adaptive grasping functionality. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0020] Figure 1 This is a schematic diagram of the overall structure of the variable stiffness flexible manipulator according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of a flexible finger according to an embodiment of the present invention.

[0022] Figure 3 This is an exploded view of the flexible finger according to an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the transmission mechanism and drive assembly according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 100. Flexible finger; 110. Finger base; 120. Finger tip block; 130. Tension spring; 131. Connecting pressure block; 140. Compression spring assembly; 141. Fin plate compression spring; 142. Fin plate corner joint block; 143. Fin plate pressure block; 144. Clamping screw; 145. Limiting screw;

[0026] 200. Transmission mechanism; 210. Trapezoidal lead screw; 220. Lead screw nut; 230. Sliding connecting plate; 240. Finger mounting base; 250. Movable connecting rod; 260. Connecting rod; 270. Limiting aluminum column; 271. Aluminum column screw; 280. Pin; 281. Snap ring;

[0027] 300. Drive assembly; 310. Drive motor; 311. Motor mounting plate; 312. Coupling; 320. Drive housing cover; 330. Drive housing body; 340. Drive housing base. Detailed Implementation

[0028] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0029] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "upper," "lower," "left," "right," "top," and "bottom" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.

[0030] Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and not for limiting the invention. The term "and / or" as used herein includes any combination of one or more of the associated listed items.

[0031] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from one another. For example, without departing from the scope of this disclosure, a first element may also be referred to as a second element, and similarly, a second element may also be referred to as a first element.

[0032] See Figures 1 to 4The present invention provides a variable stiffness flexible manipulator for adaptive grasping in extreme environments. The variable stiffness flexible manipulator includes a flexible finger 100, which comprises a finger base 110, a fingertip block 120, multiple tension springs 130, and multiple compression spring assemblies 140. The multiple tension springs 130 are respectively disposed on both sides of the finger base 110 and on both sides of the fingertip block 120. The two ends of the tension springs 130 on the same side are respectively connected to one side of the finger base 110 and the fingertip block 120. The multiple compression spring assemblies 140 are disposed between the finger base 110 and the fingertip block 120, and the two ends of the multiple compression spring assemblies 140 are respectively connected to the tension springs 130 on both sides.

[0033] See Figure 1 and Figure 2 The variable stiffness flexible manipulator of this invention includes multiple flexible fingers 100, a transmission mechanism 200, and a drive assembly 300. The flexible fingers 100 are connected to the transmission assembly 200, and the transmission mechanism 200 is connected to the drive assembly 300. Through the transmission mechanism 200, the drive mechanism 300 drives the flexible fingers 100 to open and close, thereby realizing the function of grasping objects. Further, the flexible fingers 100 include a tension spring 130 and a compression spring assembly 140. The compression spring assembly 140 includes a fin compression spring 141 (which is a compression spring). Both the tension spring 130 and the compression spring are made of spring steel and stainless steel.

[0034] This invention discloses a variable stiffness flexible manipulator for adaptive grasping in extreme environments. The flexible part of its flexible finger 100 mainly consists of a tension spring 130 and a compression spring. The springs of the flexible finger 100 are all made of 65Mn spring steel, while the rigid parts such as the fingertip block 120, the connecting parts, and the finger base are made of 304 stainless steel. Compared to the flexible materials commonly used in existing flexible fingers 100, this provides greater durability in extreme environments. Simultaneously, this flexible manipulator possesses variable stiffness capability, allowing it to actively adjust the stiffness of the fingers according to the needs of the operation or grasping task. This can be achieved by actively adjusting the finger stiffness, such as by changing the material and diameter of the thin rod inside the tension spring, thus realizing adaptive grasping functionality. Furthermore, this invention uses 65Mn spring steel and 304 stainless steel as the spring steel and stainless steel, respectively.

[0035] In some embodiments of the present invention, the flexible finger 100 includes a finger base 110, a fingertip block 120, a plurality of tension springs 130, and a plurality of compression spring assemblies 140. The plurality of tension springs 130 are respectively disposed on both sides of the finger base 110 and on both sides of the fingertip block 120. The two ends of the tension springs 130 on the same side are respectively connected to one side of the finger base 110 and the fingertip block 120. The plurality of compression spring assemblies 140 are disposed between the finger base 110 and the fingertip block 120, and the two ends of the plurality of compression spring assemblies 140 are respectively connected to the tension springs 130 on both sides.

[0036] See Figure 2 and Figure 3 The flexible finger 100 has a triangular-like structure, the finger base 110 is plate-like, and the fingertip block 120 has a triangular-like structure. The length of the finger base 110 is greater than that of the fingertip block 120. Multiple tension springs 130 are divided into two groups, one group located on each side of the finger base 110 and the other group located on each side of the fingertip block 120, thus forming a triangular frame. Multiple tension springs 130 are housed within this triangular frame. It can be understood that there are six tension springs 130, with three springs on the same side.

[0037] Furthermore, a connecting block 131 is provided on the outer side of the end of the tension spring 130. After the inner side of the end of the tension spring 130 is pressed against the side of the finger base 110 or the fingertip block 120, the connecting screw passes through the connecting block 131 to connect the finger base 110 or the fingertip block 120, thereby realizing the connection between the end of the tension spring 130 and the finger base or the fingertip block 120.

[0038] Furthermore, the tension spring 130 in this embodiment of the invention includes a clamping surface spring and a variable stiffness carbon fiber rod, with the variable stiffness carbon fiber rod inserted in the middle of the clamping surface spring. It is understood that the tension spring 130 in this embodiment of the invention has a hollow structure, and thin rods of different diameters can be installed inside the tension spring 130 according to actual needs, so that the flexible finger 100 has different variable stiffness capabilities.

[0039] In some embodiments of the present invention, the compression spring assembly 140 includes a fin compression spring 141, a fin corner joint block 142, a fin pressure block 143, and a clamping screw 144. The end of the fin compression spring 141 is connected to the fin corner joint block 142. The fin corner joint block 142 and the fin pressure block 143 are respectively disposed on the inner and outer sides of the tension spring 130. The clamping screw 144 passes through the fin corner joint block 142 and the fin pressure block 143 so that the fin corner joint block 142 and the fin pressure block 143 clamp the tension spring 130 located in the middle, thereby realizing the connection between the compression spring assembly 140 and the tension spring 130.

[0040] Furthermore, the contact surface of the fin corner joint block 142 that contacts the tension spring 130 is an inclined surface. Specifically, the fin corner joint block 142 has a near-right-angled trapezoidal structure, see [reference needed]. Figure 3 The inclined surface of the fin corner joint block 142 faces the tension spring 130, and a connecting round hole is provided on its vertical surface opposite to the inclined surface. A limiting screw 145 passes through the connecting round hole. The end of the fin compression spring 141 extends into the connecting round hole. The thread of the limiting screw 145 is engaged with the helix of the fin compression spring 141 to connect the fin compression spring 141 and the fin corner joint block 142. The inclined surface of the fin corner joint block 142 is provided with a fin semi-circular groove for abutting against the tension spring 130.

[0041] In some specific embodiments of the present invention, see Figure 3 The fin plate corner joint block 142 and the fin plate pressing block 143 are both provided with fin plate semi-circular grooves on their contact surfaces that contact the tension spring 130. When the fin plate corner joint block 142 and the fin plate pressing block 143 are connected, the two fin plate semi-circular grooves form a fin plate circular groove, and the tension spring 130 passes through the fin plate circular groove.

[0042] In some embodiments of the present invention, multiple fin compression springs 141 are provided, and the multiple fin compression springs 141 are divided into multiple groups, with the multiple groups of fin compression springs 141 arranged in layers between the finger base 110 and the fingertip block 120. Further, the multiple groups of compression spring assemblies 140 are equidistantly arranged. For example, see... Figure 2 and Figure 3 The multiple fin compression springs 141 are divided into three groups, and the three groups of fin compression springs 141 are arranged in three layers between the finger base 110 and the fingertip block 120. Furthermore, each group of fin compression springs 141 includes three fin compression springs 141.

[0043] In some embodiments of the present invention, see Figure 1 and Figure 4 The drive assembly 300 includes a drive motor 310, the output shaft of which is connected to the transmission mechanism 200 to drive the flexible finger 100 to perform a grasping operation. Specifically, one end of the drive motor 310 is connected to a trapezoidal lead screw 210 via a coupling 312, and the other end of the trapezoidal lead screw 210 is connected to the transmission mechanism 200 via a lead screw nut 220.

[0044] In some embodiments of the present invention, the drive assembly 300 includes a drive housing cover 320, a drive housing body 330, and a drive housing base 340. The drive housing cover 320 and the drive housing base 340 respectively cover both ends of the drive housing body 330. A drive motor 310 is disposed inside the drive housing body 330. The output shaft of the drive motor 310 is connected to a trapezoidal lead screw 210, which protrudes from the drive housing body 330 to connect with the transmission mechanism 200. See also Figure 4The drive box cover 320 and drive box base 340 are respectively connected to the upper and lower ends of the drive box body 330, thereby forming a closed space for accommodating the drive motor 310 and the coupling 312. A motor mounting plate 311 is provided in the closed space. The outer periphery of the motor mounting plate 311 is fixedly connected to the inner wall of the drive box cover 320. A motor connection hole is provided in the center of the motor mounting plate 311. The drive motor 310 is fixed on the motor mounting plate 311, and its output shaft passes through the motor connection hole to connect with the coupling 312.

[0045] In some embodiments of the present invention, the transmission mechanism 200 includes a trapezoidal lead screw 210, a lead screw nut 220, and a sliding connecting plate 230. The trapezoidal lead screw 210 is threadedly connected to the lead screw nut 220, the sliding connecting plate 230 is fixedly connected to the lead screw nut 220, and the trapezoidal lead screw 210 is fixedly connected to the output shaft of the drive motor 310. Thus, the drive motor 310 drives the trapezoidal lead screw 210 to rotate, causing the lead screw nut 220 and the sliding connecting plate 230 to move up and down along the trapezoidal lead screw 210, thereby driving the flexible finger 100 to perform a grasping operation. Specifically, see... Figure 1 and Figure 4 The sliding connecting plate 230 is sleeved on the outside of the lead screw nut 220, the lead screw nut 220 is located in the middle of the sliding connecting plate 230, and the trapezoidal lead screw 210 passes through the middle of the lead screw nut 220 and can protrude from the lead screw nut 220.

[0046] In some embodiments of the present invention, the transmission mechanism 200 includes a finger mounting base 240, a movable connecting rod 250, and a connecting rod 260. The finger mounting base 240 is fixedly connected to the flexible finger 100. Both ends of the movable connecting rod 250 are rotatably connected to the finger mounting base 240 and the sliding connecting plate 230, respectively. One end of the connecting rod 260 is fixedly connected to the drive housing cover 320, and the other end of the connecting rod 260 is rotatably connected to the finger mounting base 240. It should be noted that the connecting rod 260 is perpendicular to the drive housing cover 320, and the drive housing cover 320 is parallel to the sliding connecting plate 230.

[0047] See Figure 1 and Figure 4The finger mounting base 240 is fixedly connected to the lower side of the finger base 110. The inner end of the finger mounting base 240 is rotatably connected to the upper end of the movable connecting rod 250. The lower side of the finger mounting base 240 is rotatably connected to the upper side of the connecting rod 260. The lower end of the movable connecting rod 250 is rotatably connected to the outer side of the sliding connecting plate 230. Thus, when the sliding connecting plate 230 moves up and down, it drives the movable connecting rod 250 and the inner end of the finger mounting base 240 to move up and down. At the same time, it drives the finger mounting base 240 to rotate around the connecting rod 260. This, in turn, drives the upper end of the movable connecting rod 250 and the finger mounting base 240 to move inward or outward, thereby causing the fingertip of the flexible finger 100 to move outward or inward, realizing the opening and closing of the flexible finger 100. It should be noted that the finger mounting base 240 and the movable connecting rod 250, the movable connecting rod 250 and the sliding connecting plate 230, and the finger mounting base 240 and the connecting rod 260 are all rotatably connected by a pin 280 and a retaining ring 281.

[0048] In some specific embodiments of the present invention, the finger mounting base 240 includes a connecting base plate and two connecting side plates. The two connecting side plates are disposed below the connecting base plate and are respectively connected to the two sides of the connecting base plate. The connecting base plate is attached to the lower side of the finger base 110. A protrusion is provided on the lower side of the connecting side plate. The protrusion is rotatably connected to the upper side of the connecting rod 260. Further, the protrusion is disposed in the middle or on the outer side of the lower part of the finger mounting base 240.

[0049] In some specific embodiments of the present invention, the transmission mechanism 200 further includes a limiting aluminum post 270, which is rotatably connected to the finger mounting base 240. The limiting aluminum post 270 is disposed on the outside of the connecting rod 260 and is allowed to abut against the connecting rod 260. See also Figure 1 and Figure 4 The limiting aluminum post 270 is disposed between the two connecting side plates, and its two ends are rotatably connected to the two connecting side plates respectively. The limiting aluminum post 270 is located on the side of the connecting rod 260 facing away from the movable connecting rod 250. It can be understood that the limiting aluminum post 270 is connected to the finger mounting base 240 by aluminum post screws 271. Furthermore, the transmission mechanism 200 is provided with two mechanical limits, namely a lower limit position and an upper limit position. The lower limit position is where the bottom surface of the lead screw nut 220 coincides with the top surface of the drive box cover 320, and the upper limit position is where the surfaces of the limiting aluminum post 270 and the connecting rod 260 are tangent, that is, the upper limit position is the contact point between the limiting aluminum post 270 and the connecting rod 260.

[0050] Specifically, see Figure 1 and Figure 4When the flexible fingers 100 of the movable connecting plate need to close, the fingertips of multiple flexible fingers 100 need to move inward. At this time, the drive motor 310 drives the trapezoidal lead screw 210 to rotate relative to the lead screw nut 220, so that the lead screw nut 220 and the sliding connecting plate 230 move downward along the trapezoidal lead screw 210. At this time, the movable connecting rod 250 drives the inner end of the finger mounting base 240 and the finger base 110 to move downward. At the same time, the finger mounting base 240 drives the finger base 110 to rotate inward relative to the connecting rod 260, so as to realize the closing operation of multiple flexible fingers 100. Correspondingly, when the flexible fingers 100 of the movable connecting plate need to open, the fingertips of multiple flexible fingers 100 need to move outward. At this time, the drive motor 310 drives the trapezoidal screw 210 to rotate in the opposite direction relative to the screw nut 220, so that the screw nut 220 and the sliding connecting plate 230 move upward along the trapezoidal screw 210. At this time, the movable connecting rod 250 drives the inner ends of the finger mounting base 240 and the finger base 110 to move upward. At the same time, the finger mounting base 240 drives the finger base 110 to rotate outward relative to the connecting rod 260, thereby realizing the opening operation of multiple flexible fingers 100.

[0051] In some embodiments of the present invention, multiple flexible fingers 100 are provided, and further, the multiple flexible fingers 100 are evenly distributed around the drive assembly 300. Correspondingly, the number of linkage mechanisms composed of the finger mounting base 240, the movable link 250, and the connecting rod 260 is the same as the number of flexible fingers 100. Each set of linkage mechanisms is connected to one flexible finger 100 to realize the transmission between the drive assembly 300 and the flexible fingers 100. For example, if three flexible fingers 100 are provided, three sets of linkage mechanisms are provided accordingly, so that the fingertips of the three flexible fingers 100 can be simultaneously opened or closed through the three linkage mechanisms. Further, the sliding connecting plate 230 is provided with protrusions for connecting with the movable link 250, and the drive box cover 320 is provided with protrusions for connecting with the connecting rod 260. The number of protrusions and protrusions is the same as the number of flexible fingers 100.

[0052] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure, as long as they achieve the technical effects of the present invention by the same means, should be included within the scope of protection of this disclosure and fall within the protection scope of the present invention. Within the protection scope of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. A variable stiffness flexible manipulator, characterized in that, include: A flexible finger (100) includes a finger base (110), a fingertip block (120), multiple tension springs (130), and multiple compression spring assemblies (140). The multiple tension springs (130) are respectively disposed on both sides of the finger base (110) and on both sides of the fingertip block (120). The two ends of the tension springs (130) on the same side are respectively connected to one side of the finger base (110) and the fingertip block (120). The multiple compression spring assemblies (140) are disposed between the finger base (110) and the fingertip block (120), and the two ends of the multiple compression spring assemblies (140) are respectively connected to the tension springs (130) on both sides. A drive assembly (300) and a transmission mechanism (200) are provided. The drive assembly (300) includes a drive motor (310), the output shaft of which is connected to the transmission mechanism (200), which is connected to the flexible finger (100). The transmission mechanism (200) includes a trapezoidal lead screw (210), a lead screw nut (220), and a sliding connecting plate (230). The trapezoidal lead screw (210) is threadedly connected to the lead screw nut (220), the sliding connecting plate (230) is fixedly connected to the lead screw nut (220), and the trapezoidal lead screw (210) is fixedly connected to the output shaft of the drive motor (310). The compression spring assembly (140) includes a fin compression spring (141), a fin corner joint (142), a fin pressure block (143), and a clamping screw (144). The end of the fin compression spring (141) is connected to the fin corner joint (142). The fin corner joint (142) and the fin pressure block (143) are respectively disposed on the inner and outer sides of the tension spring (130). The clamping screw (144) passes through the fin corner joint (142) and the fin pressure block (143) to clamp the tension spring (130) located in the middle.

2. The variable stiffness flexible manipulator according to claim 1, characterized in that, The tension spring (130) is made of spring steel and stainless steel; the compression spring assembly (140) is also made of spring steel and stainless steel.

3. The variable stiffness flexible manipulator according to claim 1, characterized in that, The drive assembly (300) includes a drive housing cover (320), a drive housing body (330), and a drive housing base (340). The drive housing cover (320) and the drive housing base (340) respectively cover both ends of the drive housing body (330). The drive motor (310) is disposed inside the drive housing body (330), and the output shaft of the drive motor (310) is connected to the transmission mechanism (200).

4. The variable stiffness flexible manipulator according to claim 1, characterized in that, The transmission mechanism (200) further includes a finger mounting base (240), a movable connecting rod (250), and a connecting rod (260). The finger mounting base (240) is fixedly connected to the finger base (110). The two ends of the movable connecting rod (250) are rotatably connected to the finger mounting base (240) and the sliding connecting plate (230), respectively. One end of the connecting rod (260) is fixedly connected to the drive box cover (320), and the other end of the connecting rod (260) is rotatably connected to the finger mounting base (240).

5. The variable stiffness flexible manipulator according to claim 4, characterized in that, The transmission mechanism (200) further includes a limiting aluminum column (270), which is rotatably connected to the finger mounting base (240). The limiting aluminum column (270) is located on the outside of the connecting rod (260) and is allowed to abut against the connecting rod (260).

6. The variable stiffness flexible manipulator according to claim 5, characterized in that, Multiple fin compression springs (141) are provided, and the multiple fin compression springs (141) are divided into multiple groups. The multiple groups of fin compression springs (141) are arranged in layers between the finger base (110) and the fingertip block (120).

7. The variable stiffness flexible manipulator according to claim 5, characterized in that, The fin plate corner joint (142) and the fin plate pressing block (143) are both provided with fin plate semi-circular grooves on their contact surfaces that contact the tension spring (130); when the fin plate corner joint (142) and the fin plate pressing block (143) are connected, the two fin plate semi-circular grooves form a fin plate circular groove, and the tension spring (130) passes through the fin plate circular groove.

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