Adaptive bionic manipulator and differential motion pulley set mechanism thereof

Abstract

An adaptive bionic manipulator and differential motion pulley set mechanism are composed of a shell, a palm, four fingers, a thumb, and a connecting flange, and contain a first driving mechanism, a second driving mechanism, and a third driving mechanism. The four fingers include an index finger, a middle finger, a ring finger, and a little finger, which are all new tendon-rod linkage hybrid driven bionic fingers. The three knuckles of the bionic fingers move regularly under the driving of the tendons to achieve consistent bending and adaptive gripping of the fingers. A set of differential motion pulley set mechanisms is installed on the palm. The first driving mechanism drives the differential motion pulley set mechanisms and moves the four fingers. This mechanism not only solves the problem of large space occupation of the pulley set on the palm, but also reduces the overall weight and realizes lightweight. The second driving mechanism and the third driving mechanism are installed on the thumb to control the rotation and flexion of the thumb, respectively. The bionic manipulator can adaptively grasp objects, has high adaptability and high anthropomorphism, has a clever structure, and has efficient transmission.

Description

Technical Field

[0001] This invention belongs to the field of bionic robotic hand technology, and mainly relates to the structural design of an adaptive line-driven bionic finger and a bionic hand. Background Technology

[0002] Dexterous hands possess a shape and function similar to human hands, enabling them to perform grasping actions similar to those of a human hand. Therefore, since their emergence in the 1970s, dexterous hands have received significant attention from various research institutions. Underactuated dexterous hands offer advantages such as reduced system complexity and increased integration, and can also achieve adaptive grasping of the manipulated object.

[0003] Currently, in the design of existing dexterous hands, tendon rope transmission, which imitates the transmission method of animal tendons, is widely used. Tendon ropes generally have a certain degree of elasticity, providing a certain degree of flexibility and adaptability for finger movements.

[0004] However, existing technologies have many shortcomings:

[0005] For example, Chinese patent CN116000961A proposes a line-driven multi-link bionic finger mechanism. This mechanism includes a base, metacarpophalangeal bones, proximal phalanges, middle phalanges, distal phalanges, and a linkage mechanism. One end of a steel cable is fixed to the rotation axis of the metacarpophalangeal and proximal phalanges, and the other end is connected to a driving element. Driving the steel cable causes a rocker arm to swing, thereby causing the proximal phalanges to move relative to the metacarpophalangeal bones, and transmitting the power to the linkage and the next rocker arm, ultimately achieving the bending of the entire finger. The mechanism proposed in this patent solves the problem only when the object being grasped first contacts the middle phalanges. However, when the object first contacts the proximal phalanges, the finger structure cannot grip the object as tightly as a human hand, and the finger's adaptability cannot be fully realized.

[0006] Furthermore, when a human grasps, the individual finger joints not only move synchronously but also follow a specific trajectory, unaffected by any spatial posture. In contrast, the consistency of the fingers during grasping is not reflected in existing robotic hands, resulting in a low degree of anthropomorphism.

[0007] Furthermore, in current technologies, the long transmission chain of the bionic finger driven by tendon cords results in a large hand size. Consequently, the drive mechanism of existing robotic hands using pulley differential mechanisms is mostly located outside the robotic hand, which has a significant impact on the integration and control of the robotic hand. Summary of the Invention

[0008] The technical problem to be solved by this invention is to address the insufficient stiffness of existing line-driven fingers, achieve simpler and more efficient control, and utilize a novel pulley mechanism to achieve consistent bending and adaptive envelope of the four fingers within a limited palm space.

[0009] To address the aforementioned technical problems, this application provides the following technical solution:

[0010] This invention discloses an adaptive bionic robotic hand, a novel bionic robotic finger driven by a hybrid tendon-cord linkage, comprising: a palm base, a proximal phalanx, a middle phalanx, a distal phalanx, a connecting rod, a drive shaft, tendons, a first reset torsion spring, a second reset torsion spring, a third reset torsion spring, a proximal interphalangeal joint, and a distal interphalangeal joint. The joints include: a locking rivet and a miniature bearing. The palm base is located at the front end of the palm and is rotatably connected to the proximal phalanx via a cylindrical pin. The end of the proximal phalanx away from the palm base is connected to the middle phalanx via a cylindrical pin. The end of the middle phalanx away from the proximal phalanx is connected to the distal phalanx via a cylindrical pin. One end of the linkage is connected to the middle phalanx via a cylindrical pin, and the other end is fixedly connected to the drive shaft via a cylindrical pin. One end of the drive shaft is located inside the proximal phalanx, and the other end is rotatably connected to the middle phalanx. Under the pull of the tendon cord, the drive shaft drives the linkage to slide within a range in the groove inside the proximal phalanx. One end of the tendon cord is fixed to the distal phalanx via a set bolt, and the other end is connected to the drive element. Cylindrical pins are provided inside the middle phalanx, the proximal phalanx, and the palm base to guide the tendon cord.

[0011] The proximal interphalangeal joint connects the proximal phalanx and the middle phalanx, and the distal interphalangeal joint connects the middle phalanx and the distal phalanx.

[0012] The first return torsion spring is located on a cylindrical pin between the palm base and the proximal phalanx, with a certain gap between them. One end of the first return torsion spring is fixed inside the palm base, and the other end is fixed inside the proximal phalanx. The stiffness of the first return torsion spring is sufficient to ensure that the proximal phalanx and the palm base remain on the same horizontal plane without external force. The second return torsion spring is located at the proximal interphalangeal joint, with one end fixed inside the proximal phalanx and the other end fixed inside the middle phalanx. The stiffness of the second return torsion spring is sufficient to ensure that the proximal phalanx and the middle phalanx remain on the same horizontal plane without external force. The third return torsion spring is located at the distal interphalangeal joint, with one end fixed inside the middle phalanx and the other end fixed inside the distal phalanx. The stiffness of the third return torsion spring is sufficient to ensure that the middle phalanx and the distal phalanx remain on the same horizontal plane without external force. The stiffness of the return torsion springs must satisfy the following order: second return torsion spring > first return torsion spring > third return torsion spring.

[0013] The first, second, and third reset torsion springs, each with an initial torsion angle greater than 180 degrees, are mounted on cylindrical pins at the interphalangeal joints. In the absence of external force, the structure between the two phalanges limits the elastic force required for the torsion spring to return to its initial state. When the tendon cord drives the phalanges to move, the phalanges apply a torque to the torsion arm of the reset torsion spring in the opposite direction to the torsion direction during normal operation. This mounting method effectively improves the rebound speed of the reset torsion spring and avoids failure due to gravity, thereby extending the lifespan of the bionic finger.

[0014] When the tendon is subjected to driving force, it first acts on the drive shaft and then on the distal phalanx. Because the drive shaft and the connecting rod are fixed by a cylindrical pin, the connecting rod and the drive shaft move together.

[0015] The drive shaft moves within the opening groove of the proximal phalanx under the pull of the tendon cord, and drives the connecting rod and the middle phalanx to move. Because the second return torsion spring has the greatest stiffness, the middle phalanx, driven by the connecting rod, rotates together with the proximal phalanx around the cylindrical pin located between the palm base and the proximal phalanx.

[0016] When the proximal phalanx is the first to passively stop or reaches the minimum working torque of the second reset torsion spring, the middle phalanx will drive the distal phalanx to continue rotating around the proximal interphalangeal joint.

[0017] When the middle phalanx stops passively first, the proximal phalanx stops moving accordingly. Since the end of the tendon rope is fixed to the distal phalanx, the distal phalanx continues to rotate around the distal interphalangeal joint under the pull of the tendon rope. The angle of rotation is determined by the ratio of the stiffness between the third return torsion spring and the second return torsion spring.

[0018] The bionic fingers mentioned only include the index finger, middle finger, ring finger, and little finger. These four fingers have the same structure and the same transmission method.

[0019] The present invention also provides a separately designed thumb; the thumb is composed of a slider-link mechanism, including: a metacarpophalangeal joint, a proximal phalanx, a distal phalanx, a thumb drive electric cylinder, a drive slider, a cylindrical pin, a miniature bearing, a first link, and a second link.

[0020] The thumb-driven electric cylinder is located inside the palm and finger joint. One end of the driving slider is designed with an external thread, which is threaded to the end of the thumb-driven electric cylinder. The other end of the driving slider is connected to the first connecting rod through a cylindrical pin. The end of the first connecting rod away from the driving slider is provided with two through holes. The through hole near the driving slider is connected to the proximal phalanx through the cylindrical pin, and the through hole away from the driving slider is connected to the distal phalanx through the cylindrical pin. The end of the proximal phalanx near the palm joint is connected to the thumb palm joint through a locking rivet, and the end of the proximal phalanx away from the palm joint is connected to the distal phalanx through a locking rivet.

[0021] This invention also provides a novel differential moving pulley mechanism, comprising: a hand, a primary moving pulley module, a secondary moving pulley module, a tertiary moving pulley module, a quaternary moving pulley module, a primary tendon rope, a secondary tendon rope, a tertiary tendon rope, and a quaternary tendon rope. The primary, secondary, and tertiary moving pulley modules each include: a metal pulley with a V-groove and equipped with a miniature bearing, a fixed compression spring, a steel rod, a compression spring, a pulley connector, and a fixing pin; the quaternary moving pulley module includes: a hand-driven electric cylinder, a drive pulley connector, a fixing pin, a round-headed semi-threaded bolt, and a metal pulley with a V-groove and equipped with a miniature bearing. The first-stage movable pulley module connects the bionic finger to the palm via the first-stage tendon rope; the second-stage movable pulley module connects the two parallel first-stage movable pulley modules via the second-stage tendon rope; the third-stage movable pulley group module connects the bionic finger, the first-stage movable pulley, the second-stage movable pulley group, and the palm via the third-stage tendon rope; the fourth-stage pulley group module connects the palm-driven electric cylinder, the pulley group module, and the bionic finger via the tendon rope.

[0022] The aforementioned differential pulley mechanism allows four fingers to move with just one palm-driven electric cylinder. The entire drive mechanism can be completely mounted on the palm. Furthermore, the differential pulley mechanism enables self-adaptation between the four fingers during gripping. When one or more of the four fingers are in contact with the object being gripped, the remaining fingers can still bend naturally.

[0023] The differential pulley mechanism is installed on the front of the palm, while the control-related components, including a motor drive module, a voltage regulator module, a control board, and a perforated board, can be installed on the back.

[0024] The present invention provides an adaptive bionic robotic hand, which is designed with three drives, two of which control the rotation and flexion of the thumb. The entire bionic robotic hand has a total of 15 degrees of freedom.

[0025] The present invention also provides a novel bionic mechanical finger driven by a hybrid tendon-cone linkage, a bionic thumb driven by a linkage pulley mechanism, and a novel differential moving pulley group mechanism, which include the structural composition, connection method and motion control features of the above solutions, as well as driving motion features or driving characteristics.

[0026] The four fingers are driven by a new type of differential pulley mechanism to achieve consistent bending, while the thumb is driven by an independent linkage pulley mechanism to achieve rotation and flexion. The two work together to simulate the human hand to complete anthropomorphic grasping.

[0027] This invention utilizes a single tendon cord to achieve fully adaptive envelopment of an object by a bionic finger. A connecting rod is added between the middle and proximal phalanges, resulting in faster reaction speed and improved stability during grasping. Furthermore, this invention designs a novel differential pulley mechanism that enables height-adaptive grasping of the finger within a limited hand space via a single drive. This highly integrated mechanism exhibits excellent anthropomorphism in simulating human hand grasping. Compared to existing technologies, this adaptive bionic robotic hand offers at least the following advantages:

[0028] This invention incorporates a connecting rod between the proximal and middle phalanges of the bionic mechanical finger, enhancing the overall structural rigidity. By selecting return torsion springs of varying stiffness and employing a specific installation method, the bending and return speeds of the finger are improved, achieving the consistency and adaptability expected of a bionic finger.

[0029] The novel differential moving pulley system of this invention, by driving the moving pulley system in the opposite direction, enables the drive end to output a small stroke and then output double or even multiple strokes at the end of the bionic robotic hand within a limited palm space, thereby achieving bending and self-adaptation of the four fingers.

[0030] The bionic robotic hand designed in this invention has fingers designed according to the average length of an adult, and integrates the mechanical structure and control system into the hand, possessing a high degree of integration and human-likeness.

[0031] This invention utilizes a single tendon cord to achieve coupled bending and adaptive contact with objects in a single finger, simulating the movements of a real human finger. This robotic hand is low-cost to manufacture, ingeniously structured, highly efficient in transmission, highly integrated, and simple to control.

[0032] The adaptive bionic robotic hand of the present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0033] Figure 1 : An overall structural diagram of an adaptive bionic robotic hand according to the present invention;

[0034] Figure 2a , Figure 2bThese are side views of the overall structure of an adaptive bionic robotic hand according to the present invention.

[0035] Figure 3a , Figure 3b These are, respectively, the overall structural diagrams (front and back) of the index finger of an adaptive bionic robotic hand according to the present invention.

[0036] Figure 4 : A partial side view of the index finger of an adaptive bionic robotic hand according to the present invention;

[0037] Figure 5 : An exploded view of the index finger of an adaptive bionic robotic hand according to the present invention;

[0038] Figure 6a , Figure 6b This invention discloses a distribution diagram of the tendon cords of the index finger of an adaptive bionic robotic hand.

[0039] Figure 7 : An overall structural diagram of the thumb of an adaptive bionic robotic hand according to the present invention;

[0040] Figure 8 : A schematic diagram of the drive linkage structure of the thumb of an adaptive bionic robotic hand according to the present invention;

[0041] Figure 9 : An exploded view of the thumb of an adaptive bionic robotic hand according to the present invention;

[0042] Figure 10 : A schematic diagram of the movement of the thumb of an adaptive bionic robotic hand according to the present invention;

[0043] Figure 11 : Detailed view of the connection between the thumb and palm of an adaptive bionic robotic hand of the present invention;

[0044] Figure 12 : Exploded view of the connection between the thumb and palm of an adaptive bionic robotic hand of the present invention;

[0045] Figure 13 : Front view of the differential pulley system of an adaptive bionic manipulator according to the present invention;

[0046] Figure 14 : A rear view of the differential pulley system of an adaptive bionic robotic hand according to the present invention;

[0047] Figure 15 : An exploded view of the third-stage drive structure of an adaptive bionic manipulator according to the present invention;

[0048] Figure 16 Side view of a differential moving pulley system for an adaptive bionic robotic hand according to the present invention;

[0049] Figure 17 : A cross-sectional view of a differential moving pulley system for an adaptive bionic manipulator according to the present invention;

[0050] Figure 18 : Exploded view of a differential moving pulley system for an adaptive bionic manipulator according to the present invention;

[0051] Figure 19 : A schematic diagram of the tendon rope distribution of a differential moving pulley system for an adaptive bionic manipulator according to the present invention;

[0052] Figure 20 : A schematic diagram of the differential moving pulley system of an adaptive bionic manipulator according to the present invention;

[0053] Figure 21a , Figure 21b The images shown are front and side views of the four-finger bending effect of an adaptive bionic robotic hand according to the present invention.

[0054] In the picture:

[0055] 1-Index finger, 2-Middle finger, 3-Ring finger, 4-Little finger, 5-Thumb, 6-Palm, 7-Connecting flange, 8-Back of hand, 9-Hand, 10-Proximal phalanx of index finger, 11-Middle phalanx of index finger, 12-Distal phalanx of index finger, 13-Tendon of index finger, 14-Connecting rod, 15-Fasting bolt, 16-Drive shaft, 17-Connecting shaft, 18-Guide shaft, 19-Cylindrical pin, 20-Proximal interphalangeal female rivet, 21-Distal interphalangeal female rivet, 22-Distal interphalangeal male rivet, 23-Proximal interphalangeal male rivet, 24-Fixing pin, 25-First 26-Second torsion spring, 27-Third torsion spring, 28-Miniature bearing, 29-Thumb connector, 30-Thumb metacarpophalangeal joint, 31-Thumb proximal phalanx, 32-Thumb distal phalanx, 33-Second drive mechanism, 34-Cylindrical pin, 35-Drive slider, 36-First link, 37-Second link, 38-Thumb proximal interphalangeal joint rivet, 39-Thumb proximal interphalangeal joint female rivet, 40-Thumb distal interphalangeal joint rivet, 41-Thumb distal interphalangeal joint female rivet, 42-Bearing, 43-Flange connection Components: 44-Thumb motor mounting bracket, 45-L-type motor mounting bracket, 46-Third drive mechanism, 47-Connecting bearing, 48-Single movable pulley block module, 49-First type movable pulley, 50-Second type movable pulley, 51-Drive pulley, 52-Round head semi-threaded bolt, 53-Drive pulley connector, 54-First drive cylinder mounting bracket, 55-Second drive cylinder mounting bracket, 56-Voltage stabilizing module, 57-Perforated board, 58-Main control board, 59-Motor drive module, 60-First drive mechanism, 61-Drive cylinder, 62-First... 63-Pin No. 2, 64-Fasting Bolt, 65-Pulley Connector, 66-Fixing Pin, 67-Fixing Compression Spring, 68-Steel Rod, 69-Compression Spring, 70-Primary Tendon Cord, 71-Secondary Tendon Cord, 72-Tertiary Tendon Cord, 73-Fourth Tendon Cord, 75-Interphalangeal Joint, 76-Proximal Interphalangeal Joint, 77-Distal Interphalangeal Joint, 91-Opening Slot, 92-Symmetrical Hole, 102-Opening Slot, A-Primary Movable Pulley Module, B-Secondary Movable Pulley Module, C-Tertiary Movable Pulley Module, D-Fourth Movable Pulley Module. Detailed Implementation

[0056] like Figure 1 , Figure 2a and Figure 2b As shown, this invention discloses an adaptive bionic robotic hand, comprising: an index finger 1, a middle finger 2, a ring finger 3, a little finger 4, a thumb 5, a palm 9, a palm shell 6, a back shell 8, and a connecting flange 7. The palm, hand, and back are fixed together by bolts, and the dimensions of the four fingers are designed with reference to the average length of an adult finger.

[0057] Since the structures of the four fingers are similar, we will now use the structure of the index finger as an example for explanation. Figure 3a , Figure 3b , Figure 4 , Figure 5 , Figure 6a and Figure 6b As shown, the index finger structure includes: proximal phalanx 10, middle phalanx 11, distal phalanx 12, index finger tendon 13, linkage rod 14, fastening bolt 15, drive shaft 16, connecting shaft 17, guide shaft 18, cylindrical pin 19, proximal interphalangeal joint female rivet 20, distal interphalangeal joint female rivet 21, distal interphalangeal joint female rivet 22, proximal interphalangeal joint female rivet 23, fixing pin 24, first torsion spring 25, second torsion spring 26, third torsion spring 27, and miniature bearing 28. The palm 9 has a symmetrical hole 92 and an opening groove 91 at the end near the proximal knuckle 10. The proximal knuckle 10 has an opening groove 102 and a symmetrical hole 105 at the end near the palm 9. The connecting shaft 17 passes through the symmetrical hole 92, the first torsion spring 25 and the proximal knuckle symmetrical hole 105 in sequence. The torsion arm of the first torsion spring 25 near the palm 9 is placed in the opening groove 91 of the palm 9. The torsion arm of the first torsion spring 25 near the proximal knuckle 10 is placed in the opening groove 102 of the proximal knuckle 10.

[0058] The proximal phalanx 10 has an opening groove 104 and a symmetrical hole 106 at the end near the middle phalanx 11. The middle phalanx 11 has an opening groove 113 and a symmetrical hole 115 at the end near the proximal phalanx 10. The proximal interphalangeal joint female rivet 20 passes through the miniature bearing 28 in sequence. The symmetrical holes 106 of the proximal phalanx and 115 of the middle phalanx are connected to the proximal interphalangeal joint female rivet 23. The torsion arm of the second torsion spring 26 at the end near the proximal phalanx 10 is placed in the opening groove 104 of the proximal phalanx 10. The torsion arm of the second torsion spring 26 at the end near the middle phalanx 11 is placed in the opening groove 113 of the middle phalanx 11.

[0059] The connecting rod 14 is provided with a symmetrical through hole 143 at one end near the proximal phalanx 10. Two blind holes 141 and 142 are provided on the vertically symmetrical through hole 143. The drive shaft 16 passes through the through hole 143. Two through holes 161 and 162 are provided radially symmetrically on the drive shaft 16. The connecting rod and the drive shaft are fixed together by fixing pins 241 and 242.

[0060] The middle phalanx 11 has a symmetrical hole 114 at the end near the distal phalanx 12. The distal phalanx 12 has an opening groove 121 and a symmetrical hole 123 at the end near the middle phalanx 11. The distal interphalangeal joint female rivet 21 passes through the miniature bearing 28, the symmetrical hole 114 of the middle phalanx, and the symmetrical hole 123 of the distal phalanx in sequence, and finally docks with the distal interphalangeal joint female rivet 22. The torsion arm of the third torsion spring 27 near the middle phalanx 11 is placed in the opening groove 113 of the middle phalanx 11. The torsion arm of the second torsion spring 26 near the distal phalanx 12 is placed in the opening groove 121 of the distal phalanx 12.

[0061] A first torsion spring 25 is installed at the metacarpophalangeal joint 75, a second torsion spring 26 is installed at the proximal interphalangeal joint, and a third torsion spring is installed at the distal interphalangeal joint.

[0062] like Figure 4 and Figure 6a and Figure 6b As shown, the tendon cord 13 of the index finger is fixed to the end of the distal phalanx 12 with a fastening bolt 15, and then passes through the middle phalanx 11, guide shaft 18, connecting rod 14, drive shaft 16 in sequence, and is finally fixed to the pulley block mechanism on the palm.

[0063] Under the action of driving force, the index finger tendon cord 13 first transmits the force to the drive shaft 16, causing the drive shaft 16 to slide in the groove 103 in the proximal phalanx 10. The drive shaft 16 is fixed together with the connecting rod 14, which is rotatably connected to the middle phalanx 11. Therefore, after the drive shaft 16 is subjected to force, the connecting rod 14 causes the middle phalanx 11 to rotate around the proximal interphalangeal joint 76. Finally, the index finger tendon cord 13 transmits the force to the distal phalanx 12, causing the distal phalanx 12 to rotate around the distal interphalangeal joint 77.

[0064] like Figure 7 , Figure 8 and Figure 9 As shown, the main structure of the thumb 5 includes: a thumb connector 29, a thumb metacarpophalangeal joint 30, a thumb proximal joint 31, and a thumb distal joint 32. The internal linkage mechanism of the thumb 5 includes: a second drive mechanism 33, a drive slider 35, a first link 36, a second link 37, and a cylindrical pin 34. The thumb proximal joint 31, near the thumb metacarpophalangeal joint 30, has symmetrical holes 331 and 332. The thumb distal joint 32, near the end of the thumb proximal joint 31, has symmetrical holes 321 and 322. The thumb proximal female rivet 39 passes sequentially through the bearing 42, the thumb metacarpophalangeal joint 30, and the thumb proximal joint 31, and is finally hinged to the thumb proximal terminal rivet 38. The thumb distal female rivet 41 passes sequentially through the bearing 42, the thumb proximal joint 31, and the thumb distal joint 32, and is finally hinged to the thumb distal terminal rivet 40.

[0065] The output end of the second drive mechanism 33 is threadedly connected to the drive slider 35. The first connecting rod 36 is connected to the drive slider 35 via a cylindrical pin 341. The second connecting rod 37 is connected to the first connecting rod 36 via a cylindrical pin 343. The first connecting rod 36 is connected to the proximal phalanx 31 of the thumb via a cylindrical pin 342. The second connecting rod 37 is connected to the distal phalanx 32 of the thumb via a cylindrical pin 344.

[0066] like Figure 10 As shown, the proximal phalanx 31 and distal phalanx 32 of the thumb, driven by the second drive mechanism 33, can all be bent at an angle of 90 degrees using a linkage slider mechanism.

[0067] like Figure 11 and Figure 12 As shown, the detailed diagram of the connection between the thumb 5 and the palm 9 includes: the thumb 5, the flange connector 43, the thumb motor fixing part 44, the L-shaped motor fixing part 45, the third drive mechanism 46, and the connecting shaft 47. The thumb motor fixing part 44 and the L-shaped motor fixing part 45 fix the third drive mechanism 46 to the back of the palm 9. The output shaft 461 of the third drive mechanism 46 drives the thumb 5 to move. A boss 291 is designed on the back of the thumb connector 29. The boss 291 passes through the through hole 431 in the flange connector 43. The connecting bearing 47 is fixed in the through hole 431 to reduce friction.

[0068] like Figure 13 As shown, the palm 9 has a differential pulley mechanism on its front, including a first-stage pulley group module A, a second-stage pulley group module B, a third-stage pulley group module C, a fourth-stage pulley group module D, a single pulley group module 48, a drive pulley 51, a round-headed semi-threaded bolt 52, a drive pulley connector 53, a first drive electric cylinder fixing component 54, a second drive electric cylinder fixing component 55, and a first drive mechanism 60.

[0069] like Figure 14 As shown, control components are installed on the back of the palm 9, including: a voltage regulator module 56, a perforated board 57, a main control board 58, and two motor drive modules 59. All wires are led out from the through hole 431 in the connecting flange 7.

[0070] like Figure 15 , Figure 16 , Figure 17 and Figure 18 As shown, a single movable pulley module 48 includes: a first type of movable pulley 49, a fastening bolt 64, a pulley connector 65, a fixing pin 66, fixing spring plates 67, a steel bar 68, and a compression spring 69. The fixing pin 66 passes sequentially through the pulley connector 65, the first type of movable pulley 49, and the steel bar 68. The compression spring 69 is fitted onto the steel bar 68, and the two fixing spring plates 67 are fixed to the palm of the hand by the fastening bolt 64. This allows the tendon rope to drive the pulley to move on the steel bar, ensuring its stable movement.

[0071] like Figure 19As shown in the diagram, the distribution of tendon ropes in the differential moving pulley mechanism includes: primary tendon rope 70, secondary tendon rope 71, tertiary tendon rope 72, and quaternary tendon rope 73. The index finger 1 and middle finger 2 have opposite winding directions, and the winding methods of the four fingers are symmetrical in pairs. Primary tendon rope 70 serves as the driving tendon rope for the four fingers, with one end fixed to the distal phalanx of each finger. After passing through primary moving pulley module A, the other end is fixed to the palm 9. Secondary tendon rope 71 has one end fixedly connected to the pulley connector 65 in the primary moving pulley module, and after passing through the second type of moving pulley 50, it is fixedly connected to the adjacent pulley connector. Tertiary tendon rope 72 has one end fixedly connected to the pulley connector 65 in the secondary moving pulley module, and after passing through tertiary moving pulley module C, it is fixed to the palm 9. One end of the fourth-level tendon rope 73 is fixedly connected to the left pulley connector 65 in the third-level moving pulley block module. After passing through the round-headed semi-threaded bolt 52, the drive pulley 51 is finally fixedly connected to the right pulley connector 65 in the third-level moving pulley block module.

[0072] The guide function of the pulley is replaced by a round-headed semi-threaded bolt 52, and the nut of the bolt is used to prevent the tendon rope from coming off.

[0073] like Figure 20 As shown, the principle of the first-stage movable pulley block module A is the same as that of the third-stage movable pulley block module, as detailed in part (1) of the figure. The input end is... The output terminal is ,satisfy , The value of affects the degree of bending of the four fingers; see the schematic diagram of the secondary movable pulley block module B for details. Figure 20 In part (2), the input terminal is The output terminal is ,satisfy The schematic diagram of the four-stage moving pulley block module D is shown below. Figure 20 Part (3) has the following input terminal: The output terminal is ,satisfy ( ), The value is determined by the distance between the round-headed semi-threaded bolt 52 and the drive pulley 51. The value of is determined by the distance the drive pulley 51 moves.

[0074] according to Figure 19 The distribution of tendons and ligaments shown indicates that... , In summary, we can obtain That is, the distance that drives pulley 51 to move multiplied by 4 It is the distance that the first tendon rope 70 moves, and since the first tendon rope 70 directly acts on the four fingers, the distance from the electric cylinder drive end to the end output end is doubled.

[0075] When one or two fingers (two non-adjacent fingers) of the four fingers are passively stationary, the principle of the secondary movable pulley module B becomes that of the primary movable pulley module A, i.e. When three of the four fingers are passively stationary, one of the movable pulleys in the secondary movable pulley system module B is stationary. Therefore, the tertiary movable pulley system module C on the same side as the stationary movable pulley system is also stationary. Thus, the principle of the quaternary movable pulley system module D becomes the principle of the primary movable pulley system module A. When grasping irregular objects, this differential pulley module can achieve adaptive grasping with multiple degrees of freedom of the finger through a single drive.

[0076] like Figure 21a and Figure 21b The image shows two renderings illustrating the movement of the four fingers of a robotic arm driven by a differential pulley mechanism.

[0077] In summary, the overall structure of the bionic robotic hand of the present invention mainly includes: index finger, middle finger, ring finger, little finger, thumb, palm, palm shell, back shell, and connecting flange, etc.

[0078] The palm, back of the hand, and the center of the hand are fixed together with bolts, and the size of the four fingers is designed with reference to the average length of an adult's fingers.

[0079] The main structures of the four fingers (taking the index finger as an example) are as follows:

[0080] The index finger structure comprises multiple components, including the proximal phalanx, middle phalanx, distal phalanx, index finger tendon ligament, connecting rod, fastening bolt, and drive shaft. The palm is connected to the proximal phalanx, the proximal phalanx to the middle phalanx, and the middle phalanx to the distal phalanx through specific structural designs and connectors, such as cylindrical pins, interlocking rivets, and miniature bearings.

[0081] A torsion spring is installed at the corresponding joint, with its torsion arm placed in a specific groove in the phalanx. One end of the tendon cord is fixed to the distal phalanx, and it passes sequentially through the middle phalanx, guide shaft, connecting rod, and drive shaft before being fixed to a pulley system on the palm. Under the action of driving force, the tendon cord drives the movement of each component in a specific manner, realizing the movement of the index finger.

[0082] The structure and movement of the thumb are as follows:

[0083] The main structure of the thumb includes a thumb connector, thumb metacarpophalangeal joint, thumb proximal joint, and thumb distal joint. The internal linkage mechanism consists of a second drive mechanism, a drive slider, a first connecting rod, a second connecting rod, and cylindrical pins. The components are connected by cylindrical pins, locking rivets, and other means.

[0084] Driven by the second drive mechanism, the bending angle between the proximal and distal phalanges of the thumb can reach 90 degrees using the linkage and slider mechanism.

[0085] The connection between the thumb and palm is as follows: The connection includes the thumb, a flange connector, a thumb motor mount, an L-shaped motor mount, a third drive mechanism, and a connecting shaft. The thumb motor mount and the L-shaped motor mount secure the third drive mechanism to the back of the palm. The output shaft of the third drive mechanism drives the thumb. A boss is designed on the back of the thumb connector, which mates with a through hole in the flange connector, and a bearing is fixed within the through hole to reduce friction.

[0086] The differential moving pulley mechanism is as follows:

[0087] The palm features a differential pulley mechanism, which includes various levels of pulley modules, a single pulley module, a drive pulley, and round-headed semi-threaded bolts.

[0088] Control components, such as voltage regulator modules, perforated boards, main control boards, and two motor drive modules, are installed on the back of the palm. All wires are led out from the through holes in the connecting flange.

[0089] Each movable pulley module has a specific structural composition, and the coordination of each component enables the tendon rope to drive the pulley in a stable motion. The tendon rope distribution of the differential movable pulley mechanism follows a certain pattern, and each movable pulley module has a corresponding working principle. When grasping irregular objects, this differential movable pulley module can be used to achieve adaptive grasping of multiple degrees of freedom of the fingers under single drive.

[0090] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An adaptive bionic robotic hand, characterized in that, include: The outer casing, palm, four fingers, thumb, connecting flange, first drive mechanism, second drive mechanism, and third drive mechanism; The four fingers include the index finger, middle finger, ring finger, and little finger, all of which are bionic mechanical fingers driven by a novel tendon cord linkage, and are linked with a novel differential pulley mechanism on the front of the palm. A novel differential pulley system is installed on the palm of the hand, driven by a first drive mechanism; the novel differential pulley system includes a first-stage pulley module, a second-stage pulley module, a third-stage pulley module, a fourth-stage pulley module, a drive pulley connector, and first-stage tendon ropes, second-stage tendon ropes, third-stage tendon ropes, and fourth-stage tendon ropes. The first drive mechanism is placed inside the palm, and a drive pulley connector is fixed at its end. The drive pulley connector drives the fourth-level tendon rope to move. The fourth-level tendon rope passes through the fourth-level movable pulley group module. One end of the fourth-level tendon rope is fixed to the left pulley connector of the third-level movable pulley group module, and the other end is fixed to the right pulley connector of the third-level movable pulley group module. The three-level tendon rope connects the pulley connector of the two-level movable pulley module to the palm via the three-level movable pulley module. The secondary tendon rope connects the pulley connector of the primary movable pulley module to another adjacent pulley connector in the same group via the secondary movable pulley module. The primary tendon ligament is fixed at one end to the distal phalanx of the four fingers and at the other end to the palm via the primary movable pulley module; The four-level tendon rope sequentially links the three-level movable pulley module, the two-level movable pulley module, and the one-level movable pulley module, ultimately driving the one-level tendon rope to move the four fingers, realizing the transformation from a small stroke at the driving end to a multiple stroke at the four finger end, and achieving adaptive envelope through the differential speed of each level of movable pulley when the four fingers contact an object. The thumb is an independent bionic structure driven by a linkage pulley mechanism, which works in conjunction with the four fingers to achieve grasping action. It is equipped with a second drive mechanism and a third drive mechanism, which control the rotation and flexion of the thumb respectively.

2. The adaptive bionic robotic hand according to claim 1, characterized in that, The novel bionic mechanical finger with a hybrid tendon-chord linkage includes a base, metacarpophalangeal joints, proximal phalanx, proximal interphalangeal joint, middle phalanx, distal interphalangeal joint, distal phalanx, tendon cords, connecting rods, and a drive shaft. The base and proximal phalanx are connected via the metacarpophalangeal joints; the proximal and middle phalanxes are connected via the proximal interphalangeal joints; and the middle and distal phalanxes are connected via the distal interphalangeal joints.

3. The adaptive bionic robotic hand according to claim 2, characterized in that, Each joint is equipped with a torsion spring inside to maintain the straight position of the bionic finger and drive the bionic finger joint to return to its original position. On both sides of the joint, there are locking rivets and miniature bearings to connect adjacent finger joints to reduce friction between the joints.

4. The adaptive bionic robotic hand according to claim 3, characterized in that, The initial torsion angle of the torsion springs inside the joints is greater than 180 degrees, and structural restraints are used during installation to resist the elastic force of the torsion springs.

5. The adaptive bionic robotic hand according to claim 1, characterized in that, The bionic thumb driven by the linkage pulley mechanism includes a thumb metacarpophalangeal joint, a thumb proximal joint, a thumb distal joint, a second drive mechanism, a drive slider, a first link, a second link, a metacarpophalangeal joint, a proximal interphalangeal joint, and a first connecting mechanism. The thumb metacarpophalangeal joint is connected to the thumb proximal joint via the metacarpophalangeal joint, and the end of the thumb proximal joint away from the thumb metacarpophalangeal joint is connected to the thumb distal joint via the proximal interphalangeal joint. Mickeys and miniature bearings are placed on both sides of the joints to connect adjacent joints, reducing friction between them.

6. The adaptive bionic robotic hand according to claim 5, characterized in that, The second drive mechanism is placed inside the thumb metacarpophalangeal joint. The end of the second drive mechanism is connected to a drive slider. The drive slider is connected to the three phalanges in sequence through a connecting rod to realize the flexion movement of the thumb. The first connecting mechanism connects the thumb metacarpophalangeal joint and the third drive mechanism through bolts.

7. An adaptive bionic robotic hand according to claim 6, characterized in that, The primary tendon cords are arranged according to the distribution of four fingers. When at least one of the four fingers touches the object being grasped, the corresponding tendon cord will stop moving, while the other tendon cords can still move until the limit point is reached.

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