An underactuated robot finger based on a combination of link and tendon transmission

Abstract

The application discloses a kind of underactuated robot fingers based on connecting rod and tendon mechanism hybrid transmission, it is related to intelligent robot technical field.Base front end is hinged with lower swing rod bottom, rear end connects root joint shaft, lower swing rod sleeve sleeve and top fixed connection pin, driving wheel is coaxial with root joint shaft and connects tendon, arc connecting rod connects driving wheel and sleeve, adapter connecting rod front end is hinged with upper swing rod bottom, rear end connects intermediate joint shaft, upper swing rod top fixed connection pin, top joint shaft is above upper swing rod, root end, intermediate and tip knuckle shell are respectively rotationally connected with corresponding joint shaft at bottom, intermediate joint shaft is installed torsional spring, two connecting pins are respectively connected with corresponding knuckle shell.Connecting rod and tendon hybrid transmission are used, transmission efficiency is improved, smaller size and lower weight are realized by underactuated control strategy, have coupling-adaptive motion function, improve flexibility and response speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent robots, and particularly relates to an underactuated robot finger based on a mixed transmission of a connecting rod and a tendon mechanism. BACKGROUND

[0002] With the rapid development of robot technology, the design of robot fingers plays a crucial role in humanoid robots and artificial intelligence applications. In order to achieve flexible operation of robots, robot fingers not only need to have similar movement capabilities as human fingers, but also must meet the requirements of lightweight, low cost and high efficiency. However, the existing robot finger technology still has some deficiencies, especially in the design of driving mechanism and transmission mode.

[0003] At present, many robot fingers adopt a rope driving mode to realize movement, which combines one or more ropes with motor driving to drive the movement of the joints of the robot finger. Although this design is relatively common in some application scenarios, it still has obvious defects. First, the traditional rope-driven robot finger often needs high driving force and stable control when implementing complex actions, which leads to a complex structure of driving control. Second, the transmission accuracy of the traditional rope-driven robot finger is limited, especially in the process of high-frequency and complex action execution, the elasticity and wear of the rope can affect the accuracy of the finger and the stability of long-term use.

[0004] In order to overcome the defects of single rope driving mode, the present application designs an underactuated robot finger based on a mixed transmission of a connecting rod and a tendon mechanism, which forms a new mixed transmission mode in the driving aspect by combining the connecting rod mechanism and the tendon transmission, and has important significance for the optimization and improvement of the performance of the rope-driven robot finger. SUMMARY

[0005] In order to solve the deficiencies in the background art, the present application provides an underactuated robot finger based on a mixed transmission of a connecting rod and a tendon mechanism, which adopts a mixed transmission of a connecting rod and a tendon, effectively improves the transmission efficiency, realizes smaller volume and lower weight through an underactuated control strategy, and has a coupling-adaptive motion function, which can improve the flexibility and response speed of finger movement.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solutions: an under-actuated robot finger based on a hybrid transmission of a connecting rod and a tendon mechanism, comprising a base, an arc connecting rod, an upper swing rod, a tendon, a driving wheel, a lower swing rod, a root joint shaft, a sleeve, a transfer connecting rod, an intermediate joint shaft, a top joint shaft, a root end finger joint shell, an intermediate finger joint shell and a tip finger joint shell, the top front end of the base is provided with a connecting ear and is hinged to the bottom of the lower swing rod, the top of the lower swing rod is laterally fixed with an intermediate connecting pin, the sleeve is slidably sleeved on the lower swing rod, and a positioning shaft is integrally provided on the side of the bottom outer wall of the sleeve, the root joint shaft is rotatably connected to the through hole at the rear end of the top of the base, the driving wheel is coaxially connected and fixed with the root joint shaft, a winding groove is processed on the top of the driving wheel circumference and its rear end is connected and fixed with the tendon, the tendon is led out from the front end of the driving wheel, an eccentric shaft is integrally provided at the rear end of the wheel surface on the same side of the driving wheel and the positioning shaft, and shaft holes are processed at both ends of the arc connecting rod The top end face of the lifting link is fixedly mounted on the support frame, and the bottom end face of the lifting link is fixedly mounted on the support frame.

[0007] Furthermore, a sensing and communication module is fixedly installed inside the tip knuckle shell, and a proximity sensor is connected and installed on the front surface of the sensing and communication module. The proximity sensor is exposed to the outside through a window opened at the front end of the tip knuckle shell, and is used to measure the proximity information between the tip knuckle shell and the grasped object.

[0008] Furthermore, the sensing communication module is connected to the root angle sensor and the top angle sensor, the root angle sensor is fixed to the inner wall of the root end knuckle shell and is sleeved on the root joint shaft, and is used to measure the rotational position information of the driving wheel relative to the root end knuckle shell, and the top angle sensor is fixed to the inner wall of the tip knuckle shell and is sleeved on the top joint shaft, and is used to measure the rotational position information of the tip knuckle shell relative to the top joint shaft.

[0009] Further, the intermediate knuckle shell top is provided with a positioning beam, the positioning beam top is transversely provided with a nesting hole and is rotationally connected with the top joint shaft, the sensing communication module is connected with strain gauge one and strain gauge two, the strain gauge one and the strain gauge two are respectively fixed on the side and the front end of the positioning beam, and are used for measuring the stress condition of the positioning beam.

[0010] Compared with the prior art, the beneficial effects of the present application are: the present application adopts a mixed mode of connecting rods and tendons to optimize the transmission structure, which can effectively improve the transmission efficiency and reduce the mechanical loss in the traditional single rope driving mode, at the same time, with the help of underactuated control strategy, adaptive finger movement can be realized, without the need for separate driving of each joint, thereby effectively optimizing the complex structure of motor control in the traditional scheme, ensuring that the robot finger can have smaller size and lower weight on the premise of maintaining high efficient movement ability, and the underactuated robot finger has coupling-adaptive movement function, including:

[0011] 1) Human-like coupling movement in free space: when not contacting the grabbed object, the joints of the finger perform fixed proportional linkage, presenting human-like pre-grabbing action;

[0012] 2) Adaptive movement after the proximal knuckle contacts the object: after the root knuckle contacts the grabbed object, the movement is stopped, and the intermediate knuckle and the tip knuckle continue to move, realizing adaptive enveloping gripping of the object;

[0013] In summary, compared with the robot finger in the traditional single rope driving mode, the present application not only realizes a more lightweight structure in design, which helps to significantly reduce production cost, but also improves the flexibility and response speed of finger movement, and can meet more extensive application requirements. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is the internal structure diagram of the underactuated robot finger of the present application;

[0015] Figure 2 is the external structure diagram of the underactuated robot finger of the present application;

[0016] Figure 3 is the effect diagram of the underactuated robot finger of the present application applied to a humanoid robot hand.

[0017] In the figure: 1, base; 2, root pin; 3, root bearing 1; 4, arc connecting rod; 5, positioning shaft; 6, intermediate connecting pin; 7, intermediate pin; 8, intermediate bearing 1; 9, upper swing rod; 10, top connecting pin; 11, top bearing 1; 12, sensor communication module; 13, tendon rope; 14, driving wheel; 15, root bearing 2; 16, lower swing rod; 17, root angle sensor; 18, root joint shaft; 19, sleeve; 20, transfer connecting rod; 21, intermediate bearing 2; 2 2. Torsion spring; 23. Intermediate joint shaft; 24. Top bearing 2; 25. Top angle sensor; 26. Top joint shaft; 27. Proximity sensor; 28. Root knuckle housing; 29. ​​Intermediate knuckle housing; 30. Tip knuckle housing; 31. Strain gauge 1; 32. Strain gauge 2; 33. Little finger winding motor; 34. Ring finger winding motor; 35. Middle finger winding motor; 36. Index finger winding motor; 37. Thumb winding motor; 38. Thumb linear motor; 39. Rotary joint. DETAILED DESCRIPTION

[0018] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] like Figures 1-2 As shown, an under-actuated robot finger based on a hybrid transmission of a connecting rod and tendon mechanism includes a base 1, a root pin 2, a root bearing 1 3, an arc connecting rod 4, a positioning shaft 5, an intermediate connecting pin 6, an intermediate pin 7, an intermediate bearing 1 8, an upper swing rod 9, a top connecting pin 10, a top bearing 1 11, a sensor communication module 12, a tendon 13, a driving wheel 14, a root bearing 2 15, a lower swing rod 16, a root angle sensor 17, a root joint shaft 18, a sleeve 19, a connecting rod 20, an intermediate bearing 2 21, a torsion spring 22, an intermediate joint shaft 23, a top bearing 2 24, a top angle sensor 25, a top joint shaft 26, a proximity sensor 27, a root knuckle shell 28, an intermediate knuckle shell 29, a tip knuckle shell 30, a strain gauge 1 31 and a strain gauge 2 32.

[0020] Combine Figure 1As shown, the base 1 is connected as the root connector of the robot finger, the bottom is provided with mounting hole positions to facilitate installation and fixation with the palm assembly, the top extends forward and is provided with a connecting lug at the front end for the connection of the lower swing rod 16, and the top rear end is transversely provided with a through hole for the installation of the root joint shaft 18. The bottom of the lower swing rod 16 is hingedly connected with the connecting lug at the top front end of the base 1 through the root pin shaft 2 to form a rotary pair, the top of the lower swing rod 16 is transversely fixed with the middle connecting pin 6 for the connection of the middle finger joint shell 29, the sleeve 19 is slidably sleeved on the lower swing rod 16 to form a moving pair, and the outer wall bottom side of the sleeve 19 is integrally provided with the positioning shaft 5 for the connection of the arc-shaped connecting rod 4. The root joint shaft 18 is rotatably inserted into the through hole at the top rear end of the base 1, the driving wheel 14 is coaxially connected and fixed with the root joint shaft 18, the eccentric shaft is integrally arranged at the rear end of the wheel surface on the same side of the driving wheel 14, the arc-shaped connecting rod 4 is provided with shaft holes at both ends and is hingedly connected with the eccentric shaft of the driving wheel 14 and the positioning shaft 5 of the sleeve 19 to form a rotary pair, the circumferential top of the driving wheel 14 is provided with a winding groove, and the rear end thereof is connected and fixed with one end of the tendon 13, the other end of the tendon 13 is led out downward from the front end of the driving wheel 14 through the winding groove for transmitting the movement and force output by the winding motor, the rotation of the driving wheel 14 is controlled by the tendon 13 and is transmitted to the sleeve 19 through the arc-shaped connecting rod 4 to realize the sliding of the sleeve 19 and the forward swing of the lower swing rod 16. The transfer connecting rod 20 is arranged in an inclined manner along the front and rear directions above the front end adjacent position of the lower swing rod 16, the front end thereof is provided with a connecting lug for the connection of the upper swing rod 9, and the rear end thereof is transversely provided with a through hole for the installation of the middle joint shaft 23. The bottom of the upper swing rod 9 is hingedly connected with the connecting lug at the front end of the transfer connecting rod 20 through the middle pin shaft 7 to form a rotary pair, the top of the upper swing rod 9 is transversely fixed with the top connecting pin 10 for the connection of the tip finger joint shell 30, the movement and force are transmitted through the transfer connecting rod 20, and at the same time, the upper swing rod 9 is arranged in a staggered manner with the lower swing rod 16 to ensure that the working spaces of the two are not in the same plane, thereby avoiding the mutual interference of the structures when the grabbing action is realized. The middle joint shaft 23 is rotatably inserted into the through hole at the rear end of the transfer connecting rod 20, the torsional spring 22 is installed on the middle joint shaft 23 and is connected and positioned with the middle finger joint shell 29 to provide a torque opposite to the direction of the grabbing movement for the middle joint shaft 23 to realize the underdrive grabbing and automatic resetting after grabbing, and this underdrive mode can realize proportional coupling movement when not grabbing and continuous movement of the tip finger joint shell 30 after the middle finger joint shell 29 contacts the grabbed object. The top joint shaft 26 is arranged in a transverse manner above the front end adjacent position of the upper swing rod 9, and the sensing communication module 12 is arranged above the top joint shaft 26 adjacent position to realize the communication of the sensing unit.

[0021] The sensing unit includes a root angle sensor 17, a top angle sensor 25 and a proximity sensor 27. The root angle sensor 17 is installed on the root joint shaft 18 to measure the rotational position information of the driving wheel 14 relative to the root joint housing 28. The top angle sensor 25 is installed on the top joint shaft 26 to measure the rotational position information of the tip joint housing 30 relative to the top joint shaft 26. The proximity sensor 27 is installed on the front end surface of the sensing communication module 12 to measure the proximity information of the tip joint housing 30 to the object to be gripped.

[0022] In addition, in order to realize the connection of the root joint shaft 18, the intermediate joint shaft 23 and the top joint shaft 26 with the root joint housing 28, the intermediate joint housing 29 and the tip joint housing 30 respectively, the root bearing one 3 and the root bearing two 15 are arranged at both ends of the root joint shaft 18, the intermediate bearing one 8 and the intermediate bearing two 21 are arranged at both ends of the intermediate joint shaft 23, and the top bearing one 11 and the top bearing two 24 are arranged at both ends of the top joint shaft 26.

[0023] In combination Figure 2 As shown, the root joint housing 28, the intermediate joint housing 29 and the tip joint housing 30 are respectively sleeved on the lower swing rod 16, the upper swing rod 9 and the sensing communication module 12. Bearing holes are formed on both sides of the bottom of the root joint housing 28 for mounting the root bearing one 3 and the root bearing two 15 to form a rotational pair. In addition, mounting positions are arranged on the inner wall of the root joint housing 28 to mount and fix the root angle sensor 17. Bearing holes are formed on both sides of the bottom of the intermediate joint housing 29 for mounting the intermediate bearing one 8 and the intermediate bearing two 21 to form a rotational pair. At the same time, pin holes are formed on both sides of the bottom of the intermediate joint housing 29 corresponding to the intermediate connecting pin 6. The top of the lower swing rod 16 is connected to the pin holes on both sides of the bottom of the intermediate joint housing 29 through the intermediate connecting pin 6 to form a rotational pair, so that the movement and force of the lower swing rod 16 are transmitted to the intermediate joint housing 29, thereby driving the intermediate joint housing 29 to rotate around the intermediate joint shaft 23. In addition, mounting positions are arranged on the inner wall of the intermediate joint housing 29 to mount and fix the torsion spring 22. Bearing holes are formed on both sides of the bottom of the tip joint housing 30 for mounting the top bearing one 11 and the top bearing two 24 to form a rotational pair. At the same time, pin holes are formed on both sides of the bottom of the tip joint housing 30 corresponding to the top connecting pin 10. The top of the upper swing rod 9 is connected to the pin holes on both sides of the bottom of the tip joint housing 30 through the top connecting pin 10 to form a rotational pair, so that the movement and force of the upper swing rod 9 are transmitted to the tip joint housing 30, thereby driving the tip joint housing 30 to rotate around the top joint shaft 26. In addition, mounting positions are arranged on the inner wall of the tip joint housing 30 to mount and fix the sensing communication module 12 and the top angle sensor 25. A window is formed on the front end of the tip joint housing 30 to expose the proximity sensor 27 to the outside.

[0024] In addition, a positioning beam can be arranged on the top of the middle knuckle shell 29, a nesting hole is arranged on the top of the positioning beam and is connected with the top joint shaft 26, and a strain gauge I 31 and a strain gauge II 32 are respectively arranged on the side and the front end of the positioning beam and are connected with the sensing communication module 12. When the object is grabbed, the reaction force of the grabbed object can be measured through the strain gauge I 31 and the strain gauge II 32.

[0025] Compared with single rope driving or link rotation, the mechanism of the mixed transmission of the link and the tendon rope mechanism combines the characteristics of the tendon rope driving mode, such as freedom and space orientation, with the characteristics of the link, such as high rigidity and determined motion trajectory, to realize the free grabbing of the robot finger.

[0026] In combination Figure 3 As shown in the figure, based on the finger structure as a modularized finger, each modularized finger has three knuckles and three rotating joints, and a lightweight, underactuated anthropomorphic five-fingered hand is designed for the application background of humanoid robot dexterous hand and medical rehabilitation prosthesis. The whole hand is composed of a palm frame and five modularized fingers, the five modularized fingers are fixed through the mounting hole at the bottom of the base 1 and the corresponding position of the palm frame, the tendons 13 led out by the five modularized fingers are independently driven through the small finger winding motor 33, the ring finger winding motor 34, the middle finger winding motor 35, the index finger winding motor 36 and the thumb winding motor 37, and the corresponding modularized finger is bent through winding and pulling the tendon 13 to complete the grabbing action. In addition, for the thumb, an additional rotary joint 39 independently driven by a thumb linear motor 38 can be additionally matched, and the modularized finger corresponding to the thumb has two degrees of freedom of swinging and bending through extension and rotation.

[0027] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other embodiments without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent conditions of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0028] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can be properly combined to form other embodiments that those skilled in the art can understand.

Claims

1. An underactuated robot finger based on a hybrid transmission of a connecting rod and a tendon mechanism, characterized by: The invention comprises a base (1), an arc-shaped connecting rod (4), an upper swing rod (9), a tendon rope (13), a driving wheel (14), a lower swing rod (16), a root joint shaft (18), a sleeve (19), a transfer connecting rod (20), an intermediate joint shaft (23), a top joint shaft (26), a root end knuckle shell (28), an intermediate knuckle shell (29) and a tip end knuckle shell (30), wherein a connecting ear is provided at the front end of the top of the base (1) and is hinged to the bottom of the lower swing rod (16), an intermediate connecting pin (6) is fixed to the top of the lower swing rod (16), and the sleeve (19) is slidingly sleeved. On the lower swing rod (16), a positioning shaft (5) is integrally provided on the side of the bottom of the outer wall of the sleeve (19), the root joint shaft (18) is rotatably connected to the through hole at the top rear end of the base (1), the driving wheel (14) is coaxially connected and fixed to the root joint shaft (18), the top of the circumference of the driving wheel (14) is processed with a winding groove and the rear end thereof is connected and fixed with a tendon rope (13), the tendon rope (13) is led out from the front end of the driving wheel (14), the rear end of the wheel surface on the same side of the driving wheel (14) and the positioning shaft (5) is integrally provided with an eccentric shaft, and the two ends of the arc-shaped connecting rod (4) are processed with shaft holes and are respectively connected to the eccentric shaft. The spindle and the positioning shaft (5) are hinged, the transfer link (20) is arranged obliquely in the front-back direction at a position adjacent to the front end of the lower swing rod (16), the front end of the transfer link (20) is provided with a connecting ear and is hinged to the bottom of the upper swing rod (9), the top of the upper swing rod (9) is transversely fixed with a top connecting pin (10), the intermediate joint shaft (23) is rotatably connected to the through hole at the rear end of the transfer link (20), the top joint shaft (26) is transversely arranged at a position adjacent to the front end of the upper swing rod (9), and the bottom two sides of the root end knuckle shell (28) are respectively connected to the root joint shaft (18) through bearings. ) is rotatably connected, the bottom two sides of the middle finger joint shell (29) are rotatably connected to the middle joint shaft (23) through bearings, the two ends of the middle connecting pin (6) are respectively plug-connected with the pin holes opened at corresponding positions of the middle finger joint shell (29), a torsion spring (22) is installed between the middle joint shaft (23) and the middle finger joint shell (29) to provide a reverse torque, the bottom two sides of the tip finger joint shell (30) are respectively rotatably connected to the top joint shaft (26) through bearings, and the two ends of the top connecting pin (10) are respectively plug-connected with the pin holes opened at corresponding positions of the tip finger joint shell (30).

2. The underactuated robot finger based on a hybrid transmission of a connecting rod and a tendon mechanism according to claim 1, characterized in that: A sensing communication module (12) is fixedly installed inside the tip knuckle shell (30), and a proximity sensor (27) is connected and installed on the front surface of the sensing communication module (12). The proximity sensor (27) is exposed to the outside through a window provided at the front end of the tip knuckle shell (30) and is used to measure proximity information between the tip knuckle shell (30) and the grasped object.

3. The underactuated robot finger based on a hybrid transmission of a connecting rod and a tendon mechanism according to claim 2, characterized in that: The sensing communication module (12) is connected to a root angle sensor (17) and a top angle sensor (25); the root angle sensor (17) is fixedly mounted on the inner wall of a root end knuckle shell (28) and sleeved on the root joint shaft (18), and is used to measure the rotational position information of the driving wheel (14) relative to the root end knuckle shell (28); the top angle sensor (25) is fixedly mounted on the inner wall of a tip knuckle shell (30) and sleeved on the top joint shaft (26), and is used to measure the rotational position information of the tip knuckle shell (30) relative to the top joint shaft (26).

4. An underactuated robot finger based on a hybrid transmission of a connecting rod and a tendon mechanism according to claim 2 or 3, characterized in that: A positioning beam is provided on the top of the middle finger joint shell (29), and a nesting hole is provided transversely on the top of the positioning beam to be rotatably connected to the top joint shaft (26). The sensing communication module (12) is connected to strain gauge 1 (31) and strain gauge 2 (32), and the strain gauge 1 (31) and strain gauge 2 (32) are respectively fixed on the side and front end of the positioning beam to measure the force condition of the positioning beam.

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