A humanoid robot finger

Abstract

The application relates to a humanoid robot finger, belonging to the technical field of robots, which comprises a palm, a finger, a hollow cup motor, a micro roller chain, a tendon, a tensioning piece, the finger is formed by a plurality of knuckles which are hingedly connected with each other, the end of the knuckle near the palm is hingedly connected with the palm, the hollow cup motor is arranged in the palm, the side surface of each knuckle is distributed with a guide wheel, the tendon passes through the guide wheel, the tendon is connected with the two ends of the micro roller chain through a tensioning piece, the output shaft of the hollow cup motor is fixedly connected with a chain wheel, the micro roller chain is meshingly connected with the chain wheel, and the straightening and bending actions of the finger are realized through the forward and reverse rotation of the hollow cup motor. The driving mode of the combination of the micro chain transmission and the tendon is adopted, the two actions of the bending and straightening of the finger can be realized by a single motor, the reversing process relies on the meshing mechanism of the chain transmission, the operation is stable and reliable, the action delay does not occur, the whole operation track can be controlled within the expected range, and the flexibility of the finger is effectively ensured.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, specifically relating to a humanoid robot finger. Background Technology

[0002] Currently, countries worldwide are focusing on the development of humanoid robot hands (dexterous hands) as a key research topic in the field of humanoid robotics, particularly in terms of drive technology, which has been a core concern for experts from various countries. Existing drive methods are generally divided into four categories: ball screw drive, linkage drive, chord drive, and gear drive.

[0003] Ball screw drives offer high precision but are expensive to manufacture, especially for miniature ball screws used in humanoid robot hands, where a single unit can cost tens of thousands of yuan. Furthermore, the core technology is held by a few foreign companies, hindering large-scale application. Linkage drives offer high stiffness and large force transmission, but their complex design, lack of adaptability to motion, and susceptibility to dynamic loads. Gear drives offer good stability, high efficiency, and accurate transmission ratios, but are unsuitable for transmissions between two axes with long distances, particularly in three-fingered humanoid robot hands, where routine movements are difficult to achieve. Tendon-driven drives have a simple structure and are relatively easy to develop, making them the most researched method in universities. However, finger bending or straightening movements require a reset mechanism, resulting in poor finger dexterity. Summary of the Invention

[0004] To address the problems of existing technologies, this invention discloses a humanoid robot finger. Through a drive method combining micro-chain transmission and tendon rope, a single motor can realize both bending and straightening of the finger. Moreover, the reversal process relies on the meshing mechanism of the chain transmission, ensuring stable and reliable operation without slippage (action delay). The entire running trajectory can be controlled within the expected range, effectively ensuring finger flexibility.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A humanoid robot finger includes a palm, fingers, a hollow cup motor, a miniature roller chain, tendon ropes, and a tensioning element. The fingers are connected to the end of the palm and are composed of multiple phalanges that are hinged together. The end of the phalanges closest to the palm is hinged to the palm. A hollow cup motor is located inside the palm. Guide wheels are distributed on the side of each phalange. Tendon ropes pass around the guide wheels and are connected in series with tensioning elements. The two ends of the tendon ropes are connected to the two ends of the miniature roller chain. The output shaft of the hollow cup motor is fixedly connected to a sprocket, and the miniature roller chain is engaged with the sprocket. The extension and bending movements of the fingers are achieved by the forward and reverse rotation of the hollow cup motor.

[0007] Preferably, the finger joint has three segments, including a root segment, a middle segment, and a terminal segment connected sequentially from the inside out. The side of the terminal segment is provided with two first guide wheels from top to bottom, the side of the middle segment is provided with two second guide wheels from top to bottom, and the side of the root segment is provided with two third guide wheels from top to bottom. The portion of the tendon cord facing the palm passes around two second guide wheels and two first guide wheels in sequence, and the portion of the tendon cord facing the back of the hand passes around two third guide wheels in sequence and connects to the outer end of the micro roller chain. The bottom of the tendon cord on the palm side is connected to the inner end of the micro roller chain.

[0008] Preferably, in the initial state where the fingers are naturally extended, the angle R1 between the tendon cord between the second guide wheel on the palm side and the inner end of the micro roller chain and the horizontal plane is greater than 2°.

[0009] Preferably, the length L of the miniature roller chain satisfies the following condition: L = 2 * Max(L1:L2), and the chain length L1 corresponding to the wrap angle in the bending limit state and the chain length L2 corresponding to the wrap angle in the straightening limit state. In both limit states, the tendon cord does not contact the sprocket. L1 and L2 respectively represent the chain length from the outer end of the miniature roller chain to the point of tangency between the miniature roller chain and the sprocket on the side facing the palm and back of the hand when the finger is at its bending limit or straightening limit.

[0010] Preferably, the pitch P of the miniature roller chain is ≤1.905mm, and all parts are made of martensitic stainless steel, which is subjected to air cooling and tempering after vacuum heat treatment.

[0011] Preferably, after the miniature roller chain is assembled, the connection position between the pin end and the connecting hole of the outer chain plate is laser welded. The welding part is located in the vertical direction of the line connecting the centers of the two connecting holes of the outer chain plate. The angle α between the annular area on one side of the weld and the center of the pin is in the range of 10° to 30°. The weld height H1 does not exceed 50% of the pin protrusion height H2 on one side.

[0012] Preferably, the torque T of the hollow cup motor satisfies the following relationship with the pitch P of the miniature roller chain and the number of sprocket teeth Z:

[0013]

[0014] Preferably, the tendon cord is composed of multiple tendon cord segments, and a tensioning element, such as a tension spring or a rubber band, is connected between adjacent tendon cord segments.

[0015] The beneficial effects of the humanoid robot finger of this invention are as follows:

[0016] This invention proposes a novel finger-driving scheme for humanoid robots. By combining a micro-roller chain system, a tensioner, and tendon ligaments, it solves the current control problems of humanoid robot fingers, enabling precise, reciprocating, and flexible movement of multiple fingers in the humanoid robot hand. Simultaneously, the micro-roller chain system incorporates new materials and processes such as martensitic stainless steel, achieving a maintenance-free effect without compromising overall strength.

[0017] Instruction manual illustrations

[0018] Figure 1 This is a front view of a humanoid robot's finger.

[0019] Figure 2 This is a right-hand view of a humanoid robot's finger.

[0020] Figure 3 This is a schematic diagram of the maximum length of a miniature roller chain for a humanoid robot finger.

[0021] Figure 4 This is a front view of a miniature roller chain for a humanoid robot finger.

[0022] Figure 5 This is a right view of a miniature roller chain for a humanoid robot's finger.

[0023] Figure 6 This is a schematic diagram of a chain system for a humanoid robot with its fingers bent and straightened.

[0024] 1. Knuckle; 2. Tensioner; 3. Cord; 4. Miniature roller chain system; 401. Miniature roller chain; 4011. Outer chain plate; 4012. Pin; 402. Sprocket; 5. Hand; 6. Hollow cup motor; 7. First guide wheel; 8. Second guide wheel; 9. Third guide wheel. Detailed Implementation

[0025] The following description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0026] The following embodiments can be understood as illustrating a part of the structure or method of the present invention individually, or as combining the embodiments to explain the broader structure or method of the present invention.

[0027] Example 1

[0028] A humanoid robot finger, such as Figure 1 , 2As shown, the device includes a palm 5, fingers, a hollow cup motor 6, a miniature roller chain 401, a tendon cord 3, and a tensioning element 2. The fingers are connected to the end of the palm 4 and are formed by multiple phalanges 1 hinged together. The end of the phalange 1 closest to the palm 5 is hinged to the palm 5. The hollow cup motor 6 is located inside the palm 5. Guide wheels are distributed on the side of each phalange 1. The tendon cord 3 passes around the guide wheels and is connected in series with the tensioning element 2. The two ends of the tendon cord 3 are connected to the two ends of the miniature roller chain 401. The output shaft of the hollow cup motor 6 is fixedly connected to a sprocket 402. The miniature roller chain 401 is meshed with the sprocket 402. The straightening and bending movements of the fingers are achieved by the forward and reverse rotation of the hollow cup motor 6.

[0029] Example 2

[0030] like Figure 1 , 2 As shown, there are three phalanges, including the root phalange, the middle phalange, and the terminal phalange connected sequentially from the inside to the outside. The side of the terminal phalange is provided with two first guide wheels 7 from top to bottom. The side of the middle phalange is provided with two second guide wheels 8 from top to bottom. The side of the root phalange is provided with two third guide wheels 9 from top to bottom. The part of the tendon cord 3 facing the palm passes around the two second guide wheels 8 and the two first guide wheels 7 in sequence. The part of the tendon cord 3 facing the back of the hand passes around the two third guide wheels 9 and connects to the outer end of the miniature roller chain 401. The bottom of the tendon cord 3 on the palm side is connected to the inner end of the miniature roller chain.

[0031] Example 3

[0032] like Figure 2 As shown, in the initial state of naturally extended fingers, the angle R1 between the tendon cord between the second guide wheel 8 near the palm and the inner end of the miniature roller chain 401 and the horizontal plane is greater than 2°.

[0033] In this embodiment, the included angle R1 is greater than 2°, which is the minimum bending force angle of the finger. This ensures that the force direction of the finger will not produce a dead point position, that is, it will not cause the finger to bend in the opposite direction, while ensuring that it can bend towards the palm side.

[0034] Example 4

[0035] like Figure 3 As shown, the length L of the miniature roller chain 401 and the chain length L1 corresponding to the wrap angle in the bending limit state and the chain length L2 corresponding to the wrap angle in the straightening limit state satisfy: L=2*Max(L1:L2), and in both limit states, the tendon cord 3 does not contact the sprocket 402. L1 and L2 respectively represent the chain length from the outer end of the miniature roller chain 401 to the point of tangency between the miniature roller chain 401 and the sprocket 402 on the side facing the palm and back of the hand when the finger is at the bending limit or the straightening limit.

[0036] In this embodiment, if the formula L=2*Max(L1:L2) cannot be guaranteed, the tendon rope may come into contact with the sprocket, resulting in chain derailment.

[0037] Example 5

[0038] like Figure 4 As shown, the pitch P of the miniature roller chain 401 is ≤1.905mm, and all parts are made of martensitic stainless steel. After vacuum heat treatment, they are air-cooled and tempered.

[0039] like Figure 4 , 5 As shown, after the miniature roller chain 401 is assembled, the connection position between the end of the pin 4012 and the connecting hole of the outer chain plate 4011 is laser welded. The welding part is located in the vertical direction of the line connecting the centers of the two connecting holes of the outer chain plate 4011. The angle α between the annular area on one side of the weld and the center of the pin 4012 is in the range of 10° to 30°. The weld height H1 does not exceed 50% of the height H2 of the protrusion on one side of the pin 4012.

[0040] In this embodiment, since the protrusion of the miniature roller chain 401 link is small and its size is small, the existing riveting process cannot complete the riveting of this link. However, the chain riveting process is indispensable, so laser welding is used to complete the riveting process. The welding position does not coincide with the stress position of the chain plate, so it does not affect the stress of the chain plate. The single link has a good pressure output effect.

[0041] Example 6

[0042] like Figure 1 , 2 As shown, the torque T of the hollow cup motor 5 is related to the pitch P of the miniature roller chain 301 and the number of teeth Z of the sprocket 302.

[0043] Foot relationship:

[0044]

[0045] In this embodiment, the parameter is determined to be 10N based on the chain breaking force and the force exerted on most of the robotic hand fingers.

[0046] Example 7

[0047] like Figure 1 , 2 As shown, the tendon cord 3 is composed of multiple tendon cord segments, and a tensioning element 2, which is a tension spring or rubber band, is connected between adjacent tendon cord segments 3. By setting the tensioning element, it is ensured that the miniature roller chain will not derail.

[0048] Based on the above embodiments, it can be understood that: Figure 6As shown, when the hollow cup motor 6 rotates clockwise, the tendons 3 on the palm side of the finger joint 1 are tightened, and the fingers bend inward; when the hollow cup motor rotates counterclockwise, the tendons 3 on the back of the hand of the finger joint 1 are tightened, and the fingers straighten outward.

Claims

1. A humanoid robotic finger, characterized by: The device includes a palm, fingers, a hollow cup motor, a miniature roller chain, tendon ropes, and a tensioning element. The fingers are connected to the end of the palm and are composed of multiple phalanges that are hinged together. The end of the phalanges closest to the palm is hinged to the palm. A hollow cup motor is installed inside the palm. Guide wheels are distributed on the side of each phalange. Tendon ropes pass around the guide wheels and are connected in series with tensioning elements. The two ends of the tendon ropes are connected to the two ends of the miniature roller chain. The output shaft of the hollow cup motor is fixedly connected to a sprocket. The miniature roller chain meshes with the sprocket. The straightening and bending movements of the fingers are achieved by the forward and reverse rotation of the hollow cup motor.

2. The humanoid robot finger as described in claim 1, characterized in that: The finger joint has three segments, including a root segment, a middle segment, and a terminal segment connected sequentially from the inside out. The side of the terminal segment has two first guide wheels arranged sequentially from top to bottom. The side of the middle segment has two second guide wheels arranged sequentially from top to bottom. The side of the root segment has two third guide wheels arranged sequentially from top to bottom. The portion of the tendon cord facing the palm passes around two second guide wheels and two first guide wheels in sequence. The portion of the tendon cord facing the back of the hand passes around two third guide wheels in sequence and connects to the outer end of the micro roller chain. The bottom of the tendon cord on the palm side is connected to the inner end of the micro roller chain.

3. The humanoid robot finger as described in claim 2, characterized in that: in In the initial state of naturally extended fingers, the angle R1 between the tendon cord between the second guide wheel on the side closer to the palm and the inner end of the miniature roller chain and the horizontal plane is greater than 2°.

4. The humanoid robot finger as described in claim 3, characterized in that: The length L of the miniature roller chain and the chain length L1 corresponding to the wrap angle in the bending limit state and the chain length L2 corresponding to the wrap angle in the straightening limit state satisfy: L=2*Max(L1:L2), and in both limit states, the tendon cord does not contact the sprocket. L1 and L2 respectively represent the chain length from the outer end of the miniature roller chain to the point of tangency between the miniature roller chain and the sprocket on the side facing the palm and back of the hand when the finger is in the bending limit or the straightening limit.

5. A humanoid robot finger as described in claim 4, characterized in that: The pitch P of the miniature roller chain is ≤1.905mm, and all parts are made of martensitic stainless steel, which is subjected to vacuum heat treatment followed by air cooling and tempering.

6. The humanoid robot finger as described in claim 5, characterized in that: After the miniature roller chain is assembled, the connection position between the pin end and the connecting hole of the outer chain plate is laser welded. The welding part is located in the vertical direction of the line connecting the centers of the two connecting holes of the outer chain plate. The angle α between the annular area on one side of the weld and the center of the pin is in the range of 10° to 30°. The weld height H1 does not exceed 50% of the pin protrusion height H2 on one side.

7. A humanoid robot finger as described in claim 6, characterized in that: The torque T of the hollow cup motor satisfies the following relationship with the pitch P of the miniature roller chain and the number of sprocket teeth Z:

8. The humanoid robot finger as described in claim 7, characterized in that: The tendon cord is composed of multiple tendon cord segments, and a tensioning element, such as a tension spring or rubber band, is connected between adjacent tendon cord segments.

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