Multi-posture coupling linkage three-finger dexterous hand

Abstract

The invention discloses a multi-posture coupling linkage three-finger dexterous hand, and belongs to the field of structural design of robot tail end dexterous hands. The invention aims to solve the problems that the existing two-finger function is single, the structure is simple, refined operation cannot be realized, and the dexterous hand is complex in structure, high in cost and high in control algorithm difficulty. According to the technical scheme, the robot comprises a base, three dexterous finger assemblies and a rotating mechanism. The rotating mechanism drives at least one dexterous finger assembly to rotate so as to adjust the overall grabbing posture. An independent motor is arranged in each finger to drive a transmission mechanism in the finger, and the transmission mechanism achieves differential coupling linkage bending of multiple knuckles through a mixed transmission mode of a differential transmission gear set, a worm and worm wheel, a synchronous belt and the like. Compared with the prior art, through the innovative rotatable three-finger layout and a coupling transmission mechanism, high-adaptability and high-flexibility grabbing of different objects is achieved, and meanwhile the structural complexity and the production cost are remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the field of robot terminal dexterous hand structure design, and more specifically, to a three-finger dexterous hand with multi-posture coupling and linkage. Background Art

[0002] With the widespread application of robotics in industry and service fields, the performance of the dexterous hand, as the end effector of the robot, is crucial for the robot to complete complex tasks. At present, traditional manipulators are mainly divided into two categories:

[0003] The first type is a two-finger gripper. While this type of gripper has the advantages of a simple structure and easy control, its functionality is also limited. It can usually only perform basic grasping movements and cannot perform delicate operations that require higher dexterity, such as rotation and pinching.

[0004] The second category is the five-fingered humanoid hand. These robotic hands possess exceptionally high dexterity and can mimic the complex manipulations of a human hand. However, they also have significant drawbacks: their complex structure leads to high manufacturing costs; their control algorithms are extremely complex, requiring the integration and processing of data from a large number of sensors; and their reliability and safety are difficult to guarantee. These factors collectively limit the commercialization and application of these dexterous humanoid hands.

[0005] Therefore, existing technologies for dexterous robotic hands face a contradiction between functional flexibility and structural complexity, cost, and reliability. The market urgently needs a dexterous hand solution that provides sufficient flexibility to accommodate complex grasping tasks while also being feasible in terms of structure, cost, and control. Summary of the Invention

[0006] The present invention aims to solve the problems existing in the above-mentioned background technology and provide a multi-posture coupled linkage three-finger dexterous hand with a relatively simple structure, controllable cost, and high adaptability and high flexibility grasping capability.

[0007] In order to solve the above technical problems, the present invention provides a three-finger dexterous hand with multi-posture coupling and linkage, comprising: a base; three dexterous finger assemblies, each of which is mounted on the base; a rotating mechanism, which is configured to drive at least one of the three dexterous finger assemblies to rotate around the axis of connection between it and the base to adjust the overall grasping posture of the three-finger dexterous hand; and a finger transmission mechanism, each of the dexterous finger assemblies is provided with a finger transmission mechanism, which is used to drive at least two knuckles of the dexterous finger assembly in which it is located to produce a linked bending action.

[0008] In a preferred embodiment, among the three dexterous finger assemblies, one is a fixed finger and the other two are rotatable fingers; the rotation mechanism is configured to drive the two rotatable fingers to rotate relative to the base, and the rotation range can be 0-180 degrees.

[0009] In another preferred embodiment, the finger transmission mechanism is driven by a single motor, and transmits power to the finger joints through a hybrid transmission system that innovatively combines a worm transmission mechanism and a synchronous belt transmission mechanism.

[0010] Furthermore, the finger transmission mechanism also includes a set of differential transmission gear sets, which distribute power to the transmission paths driving different finger joints with a preset, non-1:1 transmission ratio, thereby realizing differential coupling and linkage of each finger joint to form an adaptive envelope grasping; in a preferred embodiment, the transmission ratio is 3:2.

[0011] Furthermore, the present invention allows for adjustment of the initial finger posture by installing an adjustment screw between the fingertip and middle phalanx. Furthermore, by integrating force sensors in the palm and fingertip, and equipping the motor with an encoder, closed-loop force and position control can be achieved, respectively, improving grasping accuracy and reliability.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. Enhanced versatility: The innovative rotatable three-finger layout greatly improves the adaptability to objects of different shapes and postures, while reducing the structural complexity caused by multi-finger redundancy.

[0014] 2. Improved grasping performance: The hybrid transmission of synchronous belt and gear is adopted to improve the load capacity and rigidity, and realize highly adaptable grasping.

[0015] 3. Reduced cost and control difficulty: Compared with the five-finger imitation human hand, the present invention has a simpler structure, lower cost, and is more convenient to control.

[0016] 4. Improved maintainability: The modular design supports the rapid replacement of parts such as knuckles, greatly facilitating maintenance and repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0018] Figure 1 This is a schematic diagram of the overall structure of a three-finger dexterous hand with multi-posture coupling and linkage according to the present invention.

[0019] Figure 2This is a schematic diagram of the overall structure of a three-finger dexterous hand with multi-posture coupling and linkage after posture transformation according to the present invention.

[0020] Figure 3 This is a schematic diagram of the exploded structure of the soft rubber component in the palm of the present invention.

[0021] Figure 4 This is a schematic structural diagram of a single dexterous finger assembly of the present invention.

[0022] Figure 5 Schematic diagram of the internal transmission mechanism of a single dexterous finger of the present invention.

[0023] Figure 6 Schematic cross-section of the dexterous hand rotation mechanism of the present invention.

[0024] Figure 7 This is a partial perspective structural diagram of the dexterous hand rotation mechanism of the present invention.

[0025] Explanation of reference numerals: 1. Palm soft glue assembly; 101. Palm soft glue; 102. FSR sensor; 103. Inside the palm shell; 104. Below the palm shell; 2. Dexterous finger assembly; 201. Distal knuckle; 202. FSR fingertip sensor; 203. Distal knuckle soft glue; 204. Adjustment screw; 205. Middle knuckle side cover; 206. Middle knuckle; 207. Middle knuckle soft glue; 208. Middle knuckle rotation axis; 209. Position sensor Sensor; 210, proximal knuckle side cover; 211, proximal knuckle soft rubber; 212, proximal knuckle; 213, single finger housing right; 214, single finger housing left; 215, single finger housing cover; 216, finger seat end cover; 217, finger seat; 218, finger seat lower bearing; 219, finger seat lower bearing pressing piece; 220, finger seat tail cover; 221, finger seat upper cover; 222, finger seat upper bearing; 223, single finger rotation gear 1; 224, flat key; 225, Synchronous pulley 1; 226, synchronous belt; 227, synchronous pulley 2; 228, turbine 1; 229, proximal knuckle rotation axis; 230, worm 1; 231, turbine 2; 232, worm 2; 233, single-finger transmission gear 1; 234, single-finger transmission gear 2; 235, worm rotation axis; 236, intermediate transmission rotation axis; 237, fixed bearing; 238, single-finger transmission gear 3; 239, single-finger transmission gear 4; 240, Star reducer; 241, motor; 242, encoder; 243, motor mount; 3, base; 4, adapter flange; 5, camera bracket; 6, camera; 7, PCBA mount; 8, PCBA board; 9, rotating mechanism; 901, servo bracket; 902, servo; 903, servo output connector; 904, servo output gear; 905, rotation transmission gear 1; 906, rotation transmission gear 2; 907, E-type retaining spring. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0027] Example 1:

[0028] refer to Figure 1 and Figure 2 , this embodiment provides a three-finger dexterous hand with multi-posture coupling linkage. Its overall structure mainly includes: a base (3), three dexterous finger assemblies (2), a transfer flange (4) for connecting to a robotic arm, a camera bracket (5) and a camera (6) mounted thereon, a PCBA fixing frame (7) and a PCBA board (8) mounted thereon, and a palm soft rubber assembly (1). Among the three dexterous finger assemblies (2), the one located in the middle is fixed to the base (3) by means of screws, etc., while the two dexterous finger assemblies (2) located on both sides are rotatable fingers that can adjust their postures, such as Figure 2 shown.

[0029] Palm soft rubber component (1) please refer to Figure 3 The palm soft rubber component (1) includes: palm soft rubber (101), FSR sensor (102), palm shell (103) and palm shell (104). The palm soft rubber (101) is fastened to the palm shell (103) by screws, and the FSR sensor (102) is placed between the two to realize the feedback of the palm force. The palm shell (103) and the palm shell (104) are fastened by screws to form a support structure of the palm part and are installed on the three dexterous finger components.

[0030] For the structure of the dexterous finger assembly (2), please refer to Figure 4 The single dexterous finger assembly (2) can be structurally divided into a finger body and a finger base. The finger body is composed of three segments connected in sequence: the third segment (distal end) includes a distal segment (201) and a distal segment soft rubber (203) wrapped therearound, and an FSR fingertip sensor (202) can also be provided at the fingertip; the second segment (middle end) includes a middle segment (206), a middle segment side cover (205) and a middle segment soft rubber (207), which is rotated by a middle segment rotation axis (208), and its rotation angle can be detected by a position sensor (209); the first segment (proximal end) includes a proximal segment (212), a proximal segment side cover (210) and a proximal segment soft rubber (211), which is rotated by a proximal segment rotation axis (229).

[0031] The distal phalanx (201) and the middle phalanx (206) are connected via an adjusting screw (204), allowing manual adjustment of the initial angle.

[0032] The finger base is used to accommodate the transmission mechanism and connect the finger body to the base (3). It is mainly composed of a finger base (217), a single finger shell right (213) and a single finger shell left (214) on the left and right sides, a single finger shell cover (215) on the top, a finger base end cover (216) at the front end, and a finger base tail cover (220) at the rear end. For a rotatable finger, its base is rotatably connected to the base (3) through a finger base upper bearing (222) and a finger base lower bearing (218), wherein the finger base upper cover (221) and the finger base lower bearing pressing piece (219) respectively fix and preload the bearing.

[0033] Implementation of the rotating mechanism (9): Reference Figure 6 and Figure 7 The rotating mechanism (9) is used to drive the dexterous finger assemblies (2) on both sides to rotate. The mechanism includes a servo (902), which is fixed to the base (3) through a servo bracket (901). The power of the servo is transmitted to the servo output gear (904) through a servo output connector (903). The servo output gear (904) transmits the power to the single-finger rotating gear 1 (223) fixed on the two rotatable dexterous finger bases through the rotating transmission gear 1 (905) and the rotating transmission gear 2 (906). Among them, the single-finger rotating gear 1 (223) realizes reliable torque transmission with the finger seat (217) through the flat key (224). The gears and other components in the transmission chain can be axially positioned by the E-type retaining ring (907). Those skilled in the art will understand that the solution of using the aforementioned "servo and gear set" to achieve drive in the current embodiment is based on consideration of structural space limitations. If space permits, the servo (902) may also be replaced by other types of drive elements, such as using a stepper motor in combination with a harmonic reducer, or directly using a high-torque direct-drive motor (DD motor), which can also achieve rotational drive of the dexterous finger assembly. These variations all fall within the protection concept of the present invention.

[0034] Implementation of the dexterous finger assembly (2) and its internal transmission mechanism: combined with reference Figure 4 and Figure 5 Each dexterous finger assembly (2) includes a set of precise internal transmission mechanisms. The finger is composed of three sections: the distal phalanx (201), the middle phalanx (206) and the proximal phalanx (212).

[0035] It is noteworthy that an adjustment screw (204) is provided at the connection between the distal phalanx (201) and the middle phalanx (206). By adjusting the screw, the initial angle of the distal phalanx relative to the middle phalanx can be changed, thereby enabling the dexterous hand to better pre-adapt to a specific grasping task.

[0036] The bending movement of the finger is driven by a single motor (241). The motor (241) is mounted on a motor mounting bracket (243), and an encoder (242) is provided at its end for position feedback. The power is transmitted to the single-finger transmission gear 3 (238) via a planetary reducer (240) and a single-finger transmission gear 4 (239). The single-finger transmission gear 3 (238) is mounted on an intermediate transmission rotating shaft (236) supported by a fixed bearing (237). The power is divided here and transmitted to a differential gear set mounted on the same worm rotating shaft (235). The differential gear set consists of a single-finger transmission gear 1 (233) and a single-finger transmission gear 2 (234), which form the core of achieving differential coupling linkage. In a preferred embodiment, the transmission ratio is designed to be 3:2. However, the present invention is not limited to this, and the transmission ratio is not the only choice. It can be changed within a certain reasonable range according to the actual grasping operation scenario to achieve different coupled grasping characteristics. The core lies in that the transmission ratio is not 1:1.

[0037] These two power sources drive the two knuckles respectively:

[0038] Path 1 (driving the proximal knuckle): the single finger transmission gear 2 (234) drives the worm 2 (232), the worm 2 (232) engages the turbine 2 (231), and the turbine 2 (231) is fixed on the proximal knuckle rotation shaft (229), thereby driving the proximal knuckle (212) to move.

[0039] Path 2 (driving the middle finger joint): the single finger transmission gear 1 (233) drives the worm 1 (230), the worm 1 (230) engages the turbine 1 (228), the turbine 1 (228) drives the synchronous pulley 2 (227), and then drives the synchronous pulley 1 (225) through the synchronous belt (226), and finally drives the middle finger joint (206) to move.

[0040] Working principle and control: When performing a grasping action, the main control PCBA board (8) receives instructions from the host computer. By driving the motor (241) to rotate, the encoder (242) behind the motor detects the magnetic field changes in real time and feeds back to the main control board, forming a precise motor position closed-loop control system. At the same time, the current detection circuit on the main control board monitors the current of each motor (241) in real time, forming a current closed-loop system, thereby realizing torque-based grasping control.

[0041] The foregoing is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A three-finger dexterous hand with multi-posture coupling linkage, characterized in that: include: a base; Three dexterous finger assemblies, each of which is mounted on the base; a rotation mechanism configured to drive at least one of the three dexterous finger assemblies to rotate about an axis connecting the at least one of the three dexterous finger assemblies to the base to adjust the overall grasping posture of the three-finger dexterous hand; Finger transmission mechanism: each of the dexterous finger components is provided with a finger transmission mechanism, and the finger transmission mechanism is used to drive at least two finger joints of the dexterous finger component in which it is located to produce a linked bending action.

2. The multi-posture coupled three-finger dexterous hand according to claim 1, characterized in that: Among the three dexterous finger assemblies, one is a fixed finger and the other two are rotatable fingers; the rotation mechanism is configured to drive the two rotatable fingers to rotate synchronously or asynchronously relative to the base.

3. The multi-posture coupled three-finger dexterous hand according to claim 2, characterized in that: The rotating mechanism drives the two rotatable fingers to rotate within a range of 0-180 degrees.

4. The multi-posture coupled three-finger dexterous hand according to claim 1, characterized in that: The finger transmission mechanism includes: a motor and a hybrid transmission system, the hybrid transmission system transmits the power of the motor to the at least two finger joints, and the hybrid transmission system includes a worm transmission mechanism and a synchronous belt transmission mechanism.

5. The multi-posture coupled three-finger dexterous hand according to claim 4, characterized in that: The finger transmission mechanism also includes a set of differential transmission gear sets, which are configured to distribute the power output from the motor to the transmission paths that respectively drive the two finger joints according to a preset transmission ratio difference, so as to achieve differential coupling linkage of the two finger joints.

6. The multi-posture coupled three-finger dexterous hand according to claim 5, characterized in that: The preset transmission ratio is a non-1:1 transmission ratio.

7. The multi-posture coupled three-finger dexterous hand according to claim 6, characterized in that: The non-1:1 transmission ratio is 3:

2.

8. The multi-posture coupled and linked three-finger dexterous hand according to claim 1, characterized in that: An adjusting screw is provided between the distal phalanx and the middle phalanx of the dexterous finger assembly for adjusting an initial angle of the distal phalanx relative to the middle phalanx.

9. The multi-posture coupled three-finger dexterous hand according to claim 1, characterized in that: It also includes a force sensor, which is arranged on the fingertip of the dexterous finger component and / or in the palm soft rubber component connected to the base.

10. The multi-posture coupled and linked three-finger dexterous hand according to claim 4, characterized in that: The end of the motor in the finger transmission mechanism is also connected to an encoder, and the encoder is used to detect the rotation angle of the motor to form a position closed-loop control.

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