A modular dexterous hand mechanical structure

Abstract

The present invention discloses a modular dexterous hand mechanical structure, comprising a palm, a thumb, and three or four fingers. The thumb comprises a thumb servo, a thumb base, a thumb base joint, a thumb base joint motor, a thumb proximal phalanx connection seat, a thumb base joint worm gear, a thumb base joint worm, a thumb proximal phalanx joint axis, a thumb proximal phalanx, a thumb coupling connecting axis 1, a thumb coupling connecting axis 2, a thumb coupling transmission connecting rod, a thumb distal phalanx joint axis, and a thumb distal phalanx. A coupled four-bar linkage is formed between the thumb proximal phalanx joint axis and the thumb coupling connecting axis 1, between the thumb proximal phalanx joint axis and the thumb distal phalanx connecting axis, between the thumb coupling connecting axis 2 and the thumb distal phalanx connecting axis, and the thumb coupling transmission connecting rod. This mechanical structure enables pinching with the thumb tip in coordination with the middle of the index finger, pinching with the thumb tip in coordination with the tip of any finger, and envelope-type grasping of the entire structure.

Description

Technical Field

[0001] The invention belongs to the technical field of robots, and in particular relates to a modular dexterous hand mechanical structure. Background Art

[0002] With the advancement of science and technology, people are increasingly eager to free themselves from repetitive mechanical labor. The demand for robots, or even partial robots, in traditional labor-intensive production tasks is growing stronger. In the field of robotics, the structural design of dexterous hands is a key research direction and a current hot topic. The human hand has over 20 degrees of freedom. Controlling all of them with motors is not only expensive but also requires high real-time control. Even grasping a simple object requires complex sensing and control. To reduce the control complexity while ensuring stable and reliable grasping, one approach is to reduce the number of motors operating simultaneously to ensure real-time grasping. However, this reduces the anthropomorphic effect of the dexterous hand, making it difficult to ensure stable and reliable grasping.

[0003] Currently, most dexterous hands use tendon transmission, an under-actuated form. Tendon transmission can only achieve flexible grasping such as envelope grasping, which is suitable for larger objects. It is difficult to pinch with fingertips and grasp thin objects. In addition, there are problems with unstable grasping and the need for pretightening. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a modular dexterous hand mechanical structure.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A modular dexterous hand mechanical structure includes a palm, a thumb, and three or four fingers; the thumb includes a thumb servo, a thumb base, a thumb base joint, a thumb base joint motor, a thumb proximal joint connection seat, a thumb base joint worm gear, a thumb base joint worm, a thumb proximal joint joint shaft, a thumb proximal joint, a thumb coupling connecting shaft 1, a thumb coupling connecting shaft 2, a thumb coupling transmission connecting rod, a thumb distal joint joint shaft, and a thumb distal joint;

[0007] The thumb servo is fixed in the notch in the middle of the palm, one end of the thumb base is fixed on the output shaft of the thumb servo, and the other end has a bent portion. Under the action of the thumb servo, the thumb base can rotate around the connection point with the output shaft of the thumb servo; the thumb base knuckle is fixed on the bent portion of the thumb base, the thumb base joint motor is embedded in the thumb base knuckle, and the output shaft of the thumb base joint motor is fixedly connected to one end of the thumb base joint worm; the thumb proximal knuckle connecting seat is fixed on the bent portion of the thumb base, the lower end of the thumb proximal knuckle is rotatably connected to the thumb proximal knuckle connecting seat through the thumb proximal knuckle joint shaft, the thumb base joint turbine is fixed on the thumb proximal knuckle joint shaft, and the thumb base joint turbine The thumb coupling transmission link is rotatably connected to the thumb coupling connection shaft 2, which is fixedly connected to the lower end of the thumb distal joint; the lower end of the thumb coupling transmission link is rotatably connected to the thumb coupling connection shaft 1, which is fixedly connected to the thumb proximal joint connection seat; the thumb proximal joint axis and the thumb coupling connection shaft 1, the thumb proximal joint axis and the thumb distal joint connection shaft, the thumb coupling connection shaft 2 and the thumb distal joint connection shaft, and the thumb coupling transmission link together constitute a coupled four-bar mechanism.

[0008] The finger includes a finger base joint, a finger base joint connecting seat, a finger base joint motor, a finger base joint worm gear, a finger base joint worm, a proximal phalanx joint shaft, a finger proximal phalanx, a finger proximal phalanx motor, a finger proximal phalanx worm gear, a finger proximal phalanx worm, a finger middle phalanx, a middle phalanx joint shaft, a finger distal phalanx, a distal phalanx joint shaft, a finger coupling connecting shaft 1, a finger coupling connecting shaft 2 and a finger coupling transmission connecting rod;

[0009] The finger base joint is installed on the upper part of the palm, the finger base joint motor is embedded in the finger base joint, and the finger base joint connecting seat is fixed to the upper end of the finger base joint; the finger base joint worm is fixedly connected to the output shaft of the finger base joint motor; the lower end of the proximal phalanx of the finger is rotatably connected to the finger base joint connecting seat through the proximal phalanx joint shaft, the finger base joint turbine is fixed on the proximal phalanx joint shaft, and the finger base joint turbine is meshed with the finger base joint worm;

[0010] The motor of the proximal joint of the finger is fixed on the proximal joint of the finger, and the worm gear of the proximal joint of the finger is fixedly connected to the output shaft of the motor of the proximal joint of the finger; the lower end of the middle joint of the finger is rotatably connected to the upper end of the proximal joint of the finger through the middle joint shaft, and the proximal joint turbine of the finger is fixed on the middle joint shaft, and the proximal joint turbine of the finger is meshed with the worm gear of the proximal joint of the finger; the lower end of the distal joint of the finger is rotatably connected to the upper end of the middle joint of the finger through the distal joint shaft; the lower end of the finger coupling transmission link is rotatably connected to the finger coupling connection shaft 1, and the finger coupling connection shaft 1 is fixedly connected to the upper end of the middle joint of the finger; the upper end of the finger coupling transmission link is rotatably connected to the finger coupling connection shaft 2, and the finger coupling connection shaft 2 is fixedly connected to the lower end of the distal joint of the finger; the middle joint shaft and the finger coupling connection shaft 1, the middle joint shaft and the distal joint shaft, the distal joint shaft and the finger coupling connection shaft 2, and the finger coupling transmission link together constitute a coupling four-bar mechanism.

[0011] The finger base joint motor, finger proximal joint motor and thumb base joint motor all adopt hollow cup motors.

[0012] The module of the finger base joint worm wheel, finger base joint worm, finger proximal joint worm wheel, finger proximal joint worm, thumb base joint worm wheel, and thumb base joint worm is all 0.3, the number of heads of the finger base joint worm, finger proximal joint worm, and thumb base joint worm is all 1, and the reduction ratio of the worm wheel and worm is all 20.

[0013] The length of the proximal phalanx of the fingers is 30-50mm, the length of the distal phalanx of the fingers is 22-25mm, the length of the middle phalanx of the fingers is 1 to 1.2 times the length of the distal phalanx of the fingers, and the total length of the fingers does not exceed 100mm; the diameter of each finger is 18 to 25mm; the length of the distal phalanx of the thumb is 25-45mm, and the length of the proximal phalanx of the thumb is 1 to 1.2 times the length of the distal phalanx of the thumb.

[0014] The transmission ratios between the distal phalanx and the middle phalanx of the finger, and between the proximal phalanx and the distal phalanx of the thumb are both 1:1, and the center distances between the middle phalanx joint axis and the finger coupling connection axis 1, and the center distances between the distal phalanx joint axis and the finger coupling connection axis 2 are both 5-8 mm.

[0015] The mechanical structure can realize pinching by cooperating the tip of the thumb with the middle of the index finger, pinching by cooperating the tip of the thumb with the tip of any finger, and envelope grabbing of the overall structure.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1) The dexterous hand is small in size: The present invention adopts a relatively small hollow cup motor, and installs the motor that drives the knuckles in the palm or adjacent knuckles. The rotation of the distal knuckles is achieved by a coupled four-bar linkage mechanism, which greatly reduces the size of the dexterous hand. The mechanical structure of the dexterous hand described in the present invention is comparable to the size of an adult hand, while reducing the number of motors.

[0018] 2) The dexterous hand is more flexible and has a good anthropomorphic effect: the present invention installs a drive motor at the active joint of the finger (proximal phalangeal joint) to increase the degree of freedom of the dexterous hand, so that the dexterous hand can complete the grasping action of more complex objects.

[0019] 3) Stable grasping of the dexterous hand: During the grasping process, the proximal knuckles of the fingers first approach the grasped object. After the proximal knuckles of the fingers touch the grasped object, the motor of the finger base joint stops running, and the motor of the proximal knuckle of the fingers starts running, driving the coupled transmission connecting rod to rotate, completing the enveloping action of the grasped object, achieving a large grasping range and stable grasping.

[0020] 4) The dexterous hand is highly practical: The present invention adopts a modular design. The thumb and finger parts are independent parts, which can be assembled and driven independently. They can cooperate to complete various actions such as lateral pinching, frontal pinching, and envelope grasping. It can realize the grasping of thin sheets, small volumes and larger volumes. It has a wider range of applications and the number of fingers can be adjusted according to actual conditions. It is highly practical.

[0021] 5) A connecting rod transmission is used between the middle and distal phalanges of the fingers, providing convenient control and stable grip, and the transmission ratio can be adjusted according to actual conditions. The dexterous hand of the present invention can perform everyday actions such as grasping and pinching, with a good anthropomorphic effect. Furthermore, it offers advantages such as low cost, light weight, and high practicality, thereby enhancing the commercial potential of the dexterous hand and meeting practical needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a schematic structural diagram of the present invention without the finger cover;

[0024] Figure 3 is a cross-sectional view of the thumb of the present invention along the axial direction;

[0025] Figure 4 is a cross-sectional view of the finger of the present invention along the axial direction;

[0026] Figure 5 This is a schematic diagram of the state of the present invention realizing the side pinching action;

[0027] Figure 6 This is a schematic diagram of the state of the present invention realizing the upright pinching action;

[0028] Figure 7 This is a schematic diagram of the state of the present invention realizing the envelope grabbing action;

[0029] In the figure: 1-palm; 2-thumb; 3-fingers;

[0030] 11-support base; 12-palm cover;

[0031] 21-thumb servo; 22-thumb base; 23-thumb base phalanx; 24-thumb base joint motor; 25-thumb proximal phalanx connector; 26-thumb base joint worm gear; 27-thumb base joint worm; 28-thumb proximal phalanx joint shaft; 29-thumb proximal phalanx; 210-thumb coupling connecting shaft 1; 211-thumb coupling connecting shaft 2; 212-thumb coupling transmission connecting rod; 213-thumb distal phalanx joint shaft; 214-thumb distal phalanx;

[0032] 31-finger base joint; 32-finger base joint connecting seat; 33-finger base joint motor; 34-finger base joint worm gear; 35-finger base joint worm; 36-proximal phalanx joint shaft; 37-proximal phalanx of finger; 38-proximal phalanx motor of finger; 39-proximal phalanx worm gear of finger; 310-proximal phalanx worm; 311-middle phalanx of finger; 312-middle phalanx joint shaft; 313-distal phalanx of finger; 314-distal phalanx joint shaft; 315-finger coupling connection shaft 1; 316-finger coupling connection shaft 2; 317-finger coupling transmission connecting rod. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below with reference to specific drawings and embodiments, which are not intended to limit the scope of protection of the present application.

[0034] The present invention is a modular dexterous hand mechanical structure (abbreviated as dexterous hand, see Figure 1-7 ), including the palm, thumb, three or four fingers; when including three fingers, they are the index finger, middle finger and ring finger. Since the little finger only plays an auxiliary role when the hand completes grasping or pinching actions, omitting the little finger can reduce the cost in terms of realizing the basic functions of the manipulator; when including four fingers, they are the index finger, middle finger, ring finger and little finger;

[0035] The thumb includes a thumb servo 21, a thumb base 22, a thumb base phalanx 23, a thumb base joint motor 24, a thumb proximal phalanx connecting seat 25, a thumb base joint worm gear 26, a thumb base joint worm 27, a thumb proximal phalanx joint shaft 28, a thumb proximal phalanx 29, a thumb coupling connecting shaft 1 210, a thumb coupling connecting shaft 211, a thumb coupling transmission connecting rod 212, a thumb distal phalanx joint shaft 213 and a thumb distal phalanx 214;

[0036] The thumb servo 21 is fixed on the palm 1, and the output end of the thumb servo 21 is located in the notch in the middle of the palm 1; one end of the thumb base 22 is fixed on the output shaft of the thumb servo 21, and the other end has a bent portion, which extends out of the notch of the palm 1; the thumb base knuckle 23 is fixed on the bent portion of the thumb base 22, and the thumb base joint motor 24 is embedded in the thumb base knuckle 23, and the output shaft of the thumb base joint motor 24 is fixedly connected to one end of the thumb base joint worm 27 through a top screw; the thumb proximal knuckle connecting seat 25 is fixed on the bent portion of the thumb base 22, and the lower end of the thumb proximal knuckle 29 is rotatably connected to the thumb proximal knuckle connecting seat 25 through the thumb proximal knuckle joint shaft 28, and the thumb base joint turbine 26 is fixed on the thumb proximal knuckle joint shaft 28, and the thumb base joint turbine 26 is meshed with the thumb base joint worm 27; the lower end of the thumb distal knuckle 214 is fixed through the thumb The distal knuckle connecting shaft 213 is rotatably connected to the upper end of the proximal knuckle 29 of the thumb; the upper end of the thumb coupling transmission link 212 is rotatably connected to the thumb coupling connection shaft 211, the thumb coupling connection shaft 211 is fixedly connected to the lower end of the distal knuckle 214 of the thumb, the lower end of the thumb coupling transmission link 212 is rotatably connected to the thumb coupling connection shaft 1 210, and the thumb coupling connection shaft 1 210 is fixedly connected to the proximal knuckle connecting seat 25 of the thumb; the proximal knuckle joint shaft 28 of the thumb and the thumb coupling connection shaft 1 210, the proximal knuckle joint shaft 28 of the thumb and the distal knuckle connecting shaft 213, the thumb coupling connection shaft 211 and the distal knuckle connecting shaft 213, and the thumb coupling transmission link 212 together constitute a coupled four-bar linkage mechanism. When the proximal knuckle 29 of the thumb rotates, the distal knuckle 214 of the thumb is passively driven to rotate by the thumb coupling transmission link 212;

[0037] The thumb base 22 is driven to rotate in the horizontal plane by the thumb servo 21, thereby realizing the rotation of the thumb relative to the palm; the thumb base joint motor 24 rotates the thumb proximal phalanx joint shaft 28 through the thumb base joint turbine 26 and the thumb base joint worm 27, thereby realizing the rotation of the thumb proximal phalanx 29 relative to the thumb base phalanx 23. Since both ends of the thumb coupling transmission link 212 are fixedly connected, when the thumb proximal phalanx 29 rotates to a certain angle, it drives the thumb distal phalanx 214 to rotate, realizing the passive movement of the thumb distal phalanx 214;

[0038] The finger 3 includes a finger base joint 31, a finger base joint connecting seat 32, a finger base joint motor 33, a finger base joint worm gear 34, a finger base joint worm 35, a proximal phalanx joint shaft 36, a finger proximal phalanx 37, a finger proximal phalanx motor 38, a finger proximal phalanx worm gear 39, a finger proximal phalanx worm 310, a finger middle phalanx 311, a middle phalanx joint shaft 312, a finger distal phalanx 313, a distal phalanx joint shaft 314, a finger coupling connecting shaft 1 315, a finger coupling connecting shaft 2 316 and a finger coupling transmission connecting rod 317;

[0039] The finger base joint 31 is mounted on the upper part of the palm 1, the finger base joint motor 33 is embedded in the finger base joint 31, and the finger base joint connecting seat 32 is fixed to the upper end of the finger base joint 31; the finger base joint worm 35 is fixedly connected to the output shaft of the finger base joint motor 33 by a jackscrew; the lower end of the finger proximal joint 37 is rotatably connected to the finger base joint connecting seat 32 by a proximal joint shaft 36, and the finger base joint turbine 34 is fixed on the proximal joint shaft 36, and the finger base joint turbine 34 is meshed with the finger base joint worm 35;

[0040] The finger proximal joint motor 38 is fixed to the finger proximal joint 37, and the finger proximal joint worm 310 is fixedly connected to the output shaft of the finger proximal joint motor 38 via a jackscrew; the lower end of the finger middle joint 311 is rotatably connected to the upper end of the finger proximal joint 37 via the middle joint joint shaft 312, and the finger proximal joint turbine 39 is fixed to the middle joint joint shaft 312, and the finger proximal joint turbine 39 is meshed with the finger proximal joint worm 310;

[0041] The lower end of the distal phalanx 313 of the finger is rotatably connected to the upper end of the middle phalanx 311 of the finger through the distal phalanx joint axis 314; the lower end of the finger coupling transmission link 317 is rotatably connected to the finger coupling connection axis 1 315, and the finger coupling connection axis 1 315 is fixedly connected to the upper end of the middle phalanx 311 of the finger; the upper end of the finger coupling transmission link 317 is rotatably connected to the finger coupling connection axis 2 316, and the finger coupling connection axis 2 316 is fixedly connected to the lower end of the distal phalanx 313 of the finger; the middle phalanx joint axis 312 and the finger coupling connection axis 1 315, the middle phalanx joint axis 312 and the distal phalanx joint axis 314, the distal phalanx joint axis 314 and the finger coupling connection axis 2 316, and the finger coupling transmission link 317 together constitute a coupled four-bar linkage mechanism. When the middle phalanx 311 of the finger rotates, the rotation of the distal phalanx 313 of the finger is passively realized through the finger coupling transmission link 317;

[0042] The finger base joint motor 33 realizes the rotation of the finger proximal joint 37 through the finger base joint worm 35 and the finger base joint worm gear 34; the finger proximal joint motor 38 realizes the rotation of the finger middle joint 311 through the finger proximal joint worm 310 and the finger proximal joint worm gear 39. Since both ends of the finger coupling transmission link 317 are fixedly connected, after the finger middle joint 311 rotates to a certain angle, it drives the finger distal joint 313 to rotate, thereby realizing passive movement of the finger distal joint 313.

[0043] The palm 1 includes a support base 11 and a palm cover 12, and the palm cover 12 is connected to the support base 11 by threads; a notch is provided in the middle of the support base 11, and the thumb servo 21 and the finger base joint 31 are both fixed on the support base 11; the control wires of each motor are led out from the wire holes of the support base 11.

[0044] In this embodiment, the finger base joint motor 33, the finger proximal joint motor 38 and the thumb base joint motor 24 are all hollow cup motors with a diameter of φ10.

[0045] In this embodiment, the module of the finger base joint worm wheel 34, the finger base joint worm 35, the finger proximal joint worm wheel 39, the finger proximal joint worm 310, the thumb base joint worm wheel 26, and the thumb base joint worm 27 is all 0.3, the number of starts of the finger base joint worm 35, the finger proximal joint worm 310, and the thumb base joint worm 27 is all 1, and the reduction ratio of the worm wheel and worm is all 20; the worm with a start number of 1 has self-locking properties, making finger movement more reliable.

[0046] In this embodiment, the proximal phalanx joint axis 36 , the middle phalanx joint axis 312 , the distal phalanx joint axis 314 , the thumb proximal phalanx joint axis 28 , and the thumb distal phalanx joint axis 23 all adopt an optical axis with a length of 20 mm and a diameter of 2 mm.

[0047] In this embodiment, the finger coupling connection axis 1 315 , the finger coupling connection axis 2 316 , the thumb coupling connection axis 1 24 and the thumb coupling connection axis 2 25 all adopt an optical axis with a length of 15 mm and a diameter of 2 mm.

[0048] In this embodiment, the length of each joint of the dexterous hand mechanical structure is obtained based on the length of each joint of the human finger: the length of the proximal joint 37 of the finger is 30-50 mm, the length of the distal joint 313 of the finger is 22-25 mm, the length of the middle joint 311 of the finger is 1 to 1.2 times that of the distal joint 313 of the finger, and the total length of the fingers does not exceed 100 mm; the diameter of each finger is 18 to 25 mm; the length of the distal joint 214 of the thumb is 25-45 mm, and the length of the proximal joint 29 of the thumb is 1 to 1.2 times that of the distal joint 214 of the thumb.

[0049] Since the transmission ratio of the distal phalanx and the middle phalanx of the finger is 1:1 when the human hand completes the grasping action, the relative rotation between the distal phalanx 313 and the middle phalanx 311 of the finger, as well as the proximal phalanx 29 of the thumb and the distal phalanx 214 of the thumb are all driven by connecting rods, and the transmission ratio is 1:1. Then, according to the length and diameter of the distal phalanx 313 and the middle phalanx 311 of the finger, the center distance between the middle phalanx joint axis 312 and the finger coupling connection axis 1 315 and the center distance between the distal phalanx joint axis 314 and the finger coupling connection axis 2 316 are determined to be 5-8 mm. Finally, the finger coupling transmission connecting rod 317 is calculated to make the finger structure more anthropomorphic.

[0050] The working principle and workflow of the present invention are:

[0051] Initial state of the fingers: the thumb servo 21 is at the 0-degree position (not working), the proximal phalanx 29 of the thumb is coplanar with the palm 1, the angle between the proximal phalanx 37 of the finger and the palm 1 is 180 degrees, the angle between the middle phalanx 311 of the finger and the distal phalanx 313 of the finger is 180 degrees, and the middle phalanx 311 of the finger and the proximal phalanx 37 of the finger form an angle of 170 degrees (there is an angle between the middle phalanx and the proximal phalanx when the human finger is naturally extended).

[0052] Lateral pinching action: as the index finger works, the motor 38 of the proximal phalanx rotates, driving the worm 310 of the proximal phalanx to move together, driving the turbine 39 of the proximal phalanx to rotate, and then driving the middle phalanx 311 of the finger to rotate in the positive direction (toward the inner side of the palm as positive). At this time, the middle phalanx 311 of the finger is the active rod, driving the finger coupling transmission connecting rod 317 to move in the positive direction, driving the distal phalanx 313 of the finger to rotate around the distal phalanx joint axis 314, realizing the positive rotation of the distal phalanx 313 of the finger; at the same time, keep the thumb servo 21 in the At 0 degrees, the thumb base joint motor 24 is driven to rotate, which drives the thumb base joint worm 27 to rotate, and the thumb base joint worm gear 26 to rotate, so that the thumb proximal joint 29 rotates forward around the thumb proximal joint axis 28. At this time, the thumb proximal joint 29 is the active rod, which drives the thumb coupling transmission link 212 to rotate forward, and drives the thumb distal joint 214 to rotate forward around the thumb distal joint axis 23 until the grasped object is pinched, completing the pinching action achieved by the thumb tip and the middle of the index finger. This action can pinch thin objects.

[0053] Orthognathic pinching action: as the index finger works, the finger base joint motor 33 starts to rotate, driving the finger base joint worm 35 to rotate together, causing the finger base joint worm gear 34 to rotate, and then driving the finger proximal joint 37 to rotate around the proximal joint joint axis 36, driving the entire finger to rotate in the forward direction; at the same time, the finger proximal joint motor 38 rotates, driving the finger proximal joint worm 310 to move together, causing the finger proximal joint turbine 39 to rotate, driving the finger middle joint 311 to move in the forward direction, at this time the finger middle joint 311 is the active rod, driving the finger coupling transmission connecting rod 317 to move in the forward direction, driving the finger distal joint 313 to rotate around the distal joint joint axis 314, realizing the forward rotation of the finger distal joint 313, until the finger distal joint The fingertip of 313 contacts the grasped object; at the same time, the output shaft of the thumb servo 21 is driven to rotate toward the center of the palm to a suitable position according to the shape and size of the grasped object, driving the thumb base joint motor 24 to rotate, driving the thumb base joint worm 27 to rotate, causing the thumb base joint worm gear 26 to rotate, driving the thumb proximal joint 29 to rotate in the forward direction around the thumb proximal joint joint axis 28. At this time, the thumb proximal joint 29 is the active rod, driving the thumb coupling transmission connecting rod 212 to rotate in the forward direction, driving the thumb distal joint 214 to rotate in the forward direction around the thumb distal joint joint axis 23, until the thumb distal joint 214 pinches the target object, completing the pinching action achieved by the thumb and index finger tips. This action can pinch smaller objects.

[0054] Enveloping grasping action: all fingers work, the finger base joint motor 33 starts to rotate, driving the finger base joint worm 35 to rotate together, causing the finger base joint worm wheel 34 to rotate, and then driving the finger proximal joint 37 to rotate around the proximal joint joint axis 36. When the finger proximal joint 37 contacts the grasped object, the finger base joint motor 33 stops rotating; then the finger proximal joint motor 38 rotates, driving the finger proximal joint worm 310 to move together, causing the finger proximal joint turbine 39 to rotate, driving the finger middle joint 311 to move forward. At this time, the finger middle joint 311 is the active rod, driving the finger coupling transmission link 317 to move forward, driving the finger distal joint 313 to rotate around the distal joint joint axis 314, realizing the finger distal joint 3 13 rotates forward until the distal phalanx 313 of the finger also contacts the grasped object, ensuring a stable grasp; at the same time, the output shaft of the thumb servo 21 is driven to rotate toward the center of the palm to a suitable position according to the shape and size of the grasped object, driving the thumb base joint motor 24 to rotate, driving the thumb base joint worm 27 to rotate, causing the thumb base joint worm gear 26 to rotate, driving the thumb proximal phalanx 29 to rotate forward around the thumb proximal phalanx joint axis 28. At this time, the thumb proximal phalanx 29 is the active rod, driving the thumb coupling transmission connecting rod 212 to rotate forward, driving the thumb distal phalanx 214 to rotate forward around the thumb distal phalanx joint axis 23 until the grasped object is grasped, realizing the envelope grasping action of the entire hand, and completing the grasping of larger objects.

[0055] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A modular dexterous hand mechanical structure comprising a palm, a thumb, and three or four fingers; characterized in that: The thumb includes a thumb servo, a thumb base, a thumb base joint, a thumb base joint motor, a thumb proximal phalanx connection seat, a thumb base joint worm gear, a thumb base joint worm, a thumb proximal phalanx joint shaft, a thumb proximal phalanx, a thumb coupling connection shaft 1, a thumb coupling connection shaft 2, a thumb coupling transmission connecting rod, a thumb distal phalanx joint shaft and a thumb distal phalanx; The thumb servo is fixed in the notch in the middle of the palm, one end of the thumb base is fixed on the output shaft of the thumb servo, and the other end has a bent portion. Under the action of the thumb servo, the thumb base can rotate around the connection point with the output shaft of the thumb servo; the thumb base knuckle is fixed on the bent portion of the thumb base, the thumb base joint motor is embedded in the thumb base knuckle, and the output shaft of the thumb base joint motor is fixedly connected to one end of the thumb base joint worm; the thumb proximal knuckle connecting seat is fixed on the bent portion of the thumb base, the lower end of the thumb proximal knuckle is rotatably connected to the thumb proximal knuckle connecting seat through the thumb proximal knuckle joint shaft, the thumb base joint turbine is fixed on the thumb proximal knuckle joint shaft, and the thumb base joint turbine The thumb coupling transmission link is rotatably connected to the thumb coupling connection shaft 2, which is fixedly connected to the lower end of the thumb distal joint; the lower end of the thumb coupling transmission link is rotatably connected to the thumb coupling connection shaft 1, which is fixedly connected to the thumb proximal joint connection seat; the thumb proximal joint joint axis and the thumb coupling connection shaft 1, the thumb proximal joint axis and the thumb distal joint connection axis, the thumb coupling connection shaft 2 and the thumb distal joint connection axis, and the thumb coupling transmission link together constitute a coupled four-bar linkage; The finger includes a finger base joint, a finger base joint connecting seat, a finger base joint motor, a finger base joint worm gear, a finger base joint worm, a proximal phalanx joint shaft, a finger proximal phalanx, a finger proximal phalanx motor, a finger proximal phalanx worm gear, a finger proximal phalanx worm, a finger middle phalanx, a middle phalanx joint shaft, a finger distal phalanx, a distal phalanx joint shaft, a finger coupling connecting shaft 1, a finger coupling connecting shaft 2 and a finger coupling transmission connecting rod; The finger base joint is installed on the upper part of the palm, the finger base joint motor is embedded in the finger base joint, and the finger base joint connecting seat is fixed to the upper end of the finger base joint; the finger base joint worm is fixedly connected to the output shaft of the finger base joint motor; the lower end of the proximal phalanx of the finger is rotatably connected to the finger base joint connecting seat through the proximal phalanx joint shaft, the finger base joint turbine is fixed on the proximal phalanx joint shaft, and the finger base joint turbine is meshed with the finger base joint worm; The motor for the proximal joint of the finger is fixed on the proximal joint of the finger, and the worm gear for the proximal joint of the finger is fixedly connected to the output shaft of the motor for the proximal joint of the finger; the lower end of the middle joint of the finger is rotatably connected to the upper end of the proximal joint of the finger through the middle joint joint shaft, and the proximal joint turbine of the finger is fixed on the middle joint joint shaft, and the proximal joint turbine of the finger is meshed with the worm gear for the proximal joint of the finger; the lower end of the distal joint of the finger is rotatably connected to the upper end of the middle joint of the finger through the distal joint joint shaft; the lower end of the finger coupling transmission link is rotatably connected to the finger coupling connection shaft 1, and the finger coupling connection shaft 1 is fixedly connected to the upper end of the middle joint of the finger; the upper end of the finger coupling transmission link is rotatably connected to the finger coupling connection shaft 2, and the finger coupling connection shaft 2 is fixedly connected to the lower end of the distal joint of the finger; a coupling four-bar mechanism is formed between the middle joint shaft and the finger coupling connection shaft 1, between the middle joint shaft and the distal joint shaft, between the distal joint shaft and the finger coupling connection shaft 2, and the finger coupling transmission link; The finger base joint motor, finger proximal joint motor and thumb base joint motor all adopt hollow cup motors; The module of the finger base joint worm wheel, finger base joint worm, finger proximal joint worm wheel, finger proximal joint worm, thumb base joint worm wheel, and thumb base joint worm is all 0.3, the number of heads of the finger base joint worm, finger proximal joint worm, and thumb base joint worm is all 1, and the reduction ratio of the worm wheel and worm is all 20.

2. The modular dexterous hand mechanical structure according to claim 1, characterized in that: The length of the proximal phalanx of the fingers is 30-50mm, the length of the distal phalanx of the fingers is 22-25mm, the length of the middle phalanx of the fingers is 1-1.2 times the length of the distal phalanx of the fingers, and the total length of the fingers does not exceed 100mm; the diameter of each finger is 18-25mm; the length of the distal phalanx of the thumb is 25-45mm, and the length of the proximal phalanx of the thumb is 1-1.2 times the length of the distal phalanx of the thumb.

3. The modular dexterous hand mechanical structure according to claim 2, characterized in that: The transmission ratios between the distal phalanx and the middle phalanx of the finger, and between the proximal phalanx and the distal phalanx of the thumb are both 1:1, and the center distances between the middle phalanx joint axis and the finger coupling connection axis 1, and the center distances between the distal phalanx joint axis and the finger coupling connection axis 2 are both 5-8 mm.

4. The modular dexterous hand mechanical structure according to any one of claims 1 to 3, characterized in that: The mechanical structure can realize pinching by cooperating the tip of the thumb with the middle of the index finger, pinching by cooperating the tip of the thumb with the tip of any finger, and envelope grabbing of the overall structure.

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