A rope-driven under-actuated five-finger manipulator

Abstract

The present invention relates to a rope-driven under-driven five-finger manipulator, comprising a palm component, a thumb component and a four-finger component mounted on the palm component, and a steel wire rope; the present invention can realize the manipulator grasping objects in various ways through the step-by-step operation and synchronous operation of three rotating motors in the palm; by adopting a rope-pulley system structure driven by a rope, the number of finger driving motors is reduced without affecting the daily life function of the manipulator, thereby reducing the manufacturing cost and weight of the manipulator, and compacting the driving elements inside the palm, so that the fingers themselves are lighter and more compact, and the movement is more stable; the present invention can not only perform adaptive grasping of objects, but also actively adjust the postures of the fingers to appropriate positions for more accurate grasping.

Description

Technical Field

[0001] The invention relates to the technical field of robots, in particular to a rope-driven under-driven five-finger manipulator. Background Art

[0002] In recent years, with the rapid development of the economy, robots have also developed rapidly and have been widely used in various fields. The manipulator is the final actuator of the robot's work, and its performance directly determines the robot's working ability.

[0003] The contact between the robot and the environment relies on the end effector. Early manipulators were mainly simple clamp-type and parallel moving mechanisms, which were basically used in automated production lines in factories and had poor versatility. At present, there are various studies on multi-finger manipulators, from external structures to internal tendon transmission systems. Domestically, there are research results from Tsinghua University, Beihang University, Tianjin University, Harbin Institute of Technology and other schools and research institutes. There are generally problems of poor reliability, large mass and low flexibility. Highly under-actuated manipulators can often only achieve passive adaptation but not active control. Foreign research on manipulators by Shadow Company in the UK and Schunk Company in Germany has higher intelligence and flexibility, but the number of drive motors is large, the control system is complex and the cost is high, which is not conducive to investing in the affordable market. Therefore, the development of a five-finger flexible under-actuated manipulator with high versatility, dexterity and light mass is very necessary. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a rope-driven under-driven five-finger manipulator, which is driven by three motors with 11 degrees of freedom and 4 coupled degrees of freedom to achieve the bending of five fingers and the swing of the thumb. It can adaptively grasp and actively adjust the posture to a suitable position.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme.

[0006] A rope-driven under-actuated five-finger manipulator comprises a palm component 1, a four-finger component 2 and a thumb component 3 mounted on the palm component, and three drives; the five-finger manipulator has a total of 11 active degrees of freedom and 4 coupled degrees of freedom; the four-finger component 2 comprises a completely identical index finger, middle finger, ring finger and little finger, and each finger of the four-finger component 2 consists of a proximal joint 26, a middle joint 24 and a distal joint rod 21; the thumb component 3 comprises a thumb proximal joint rod 35, a thumb distal joint rod 31 and a metacarpal joint 314 of the thumb; the rope-driven under-actuated five-finger manipulator has a force grasping mode and a precision grasping mode.

[0007] The present invention has a compact structure and light weight. Three motors control 11 active degrees of freedom and 4 coupled degrees of freedom. It can complete adaptive grasping and actively adjust the posture to a suitable position. The operation is light and flexible.

[0008] Preferably, the four-finger assembly consists of a proximal joint 26, a middle joint 24, and a distal joint 21; a steel wire rope 220 passes around a proximal joint pulley 218, one end of which is connected to a tension spring 110, and the other end is connected to a first movable pulley 15 in the palm, and the first movable pulley 15 moves linearly to drive the bending of the proximal joint; a steel wire rope 212 passes around a double-groove pulley 210, one end of which is connected to a tension spring 111, and the other end is connected to a second movable pulley 16 in the palm, a steel wire rope 3 217 passes around a double-groove pulley 210 to form a synchronous transmission with a middle joint pulley 25, and the second movable pulley 16 moves linearly to drive the bending of the middle joint; a steel wire rope 4 214 cross-wraps around a middle joint pulley 215 and a distal joint pulley 213 to form a cross tendon, so that the proximal joint and the middle joint work together to couple and drive the bending of the distal joint.

[0009] The rope and pulley in the four-finger assembly work together to couple and drive the distal joint to bend. Multiple motor drives are not required. Each finger has three degrees of freedom and a large working space, and can perform grasping actions in various postures such as tight grip, pinching, and side pinching.

[0010] Preferably, the thumb assembly is composed of a metacarpal joint 314, a thumb proximal joint rod 35, and a thumb distal joint rod 31; a motor three 118 controls the swing of the metacarpal joint; a steel wire rope eight 312 passes around a proximal joint pulley two 310, one end of which is connected to a tension spring three 120, and the other end is connected to a first movable pulley in the palm, and the first movable pulley moves linearly to drive the proximal joint of the thumb to bend; a steel wire rope nine 313 passes around a proximal joint double-groove pulley two 36, one end of which is connected to a tension spring four 121, and the other end is connected to a second movable pulley in the palm, and a steel wire rope seven 39 passes around a double-groove pulley one to form a synchronous transmission with a distal joint pulley two 34, and the second movable pulley moves linearly to drive the distal joint of the thumb to bend.

[0011] Motor three drives the thumb assembly to swing for adaptive grasping. At the same time, motor three can drive the thumb assembly to actively adjust its posture to adapt to grasping tasks with different requirements.

[0012] Preferably, the palm assembly is composed of a palm front plate 12, a palm rear plate 11, a T-slot 14, a first movable pulley 15, a second movable pulley 16, a first fixed pulley 17, a second fixed pulley 18, a steering wheel 116, a wire rope, a motor, a winding wheel 128, a motor one L-shaped plate 127 and a motor two L-shaped plate 131; one end of the wire rope five 123 is fixed to the winding wheel 128 on the motor one 126, bypassing the five first fixed pulleys and the five first movable pulleys, and the other end is connected to the tension spring five 125, and the linear motion of the five first movable pulleys is controlled by the rotation of the motor one, that is, the proximal joints of the five fingers are bent; one end of the wire rope six 122 is fixed to the winding wheel on the motor two 130, bypassing the five second fixed pulleys and the five second movable pulleys, and the other end is connected to the tension spring six 124, and the linear motion of the five second movable pulleys is controlled by the rotation of the motor two, that is, the distal joint bending of the thumb and the middle joint bending of the four fingers.

[0013] Motor one and motor two can work in steps to achieve precise grasping, and can also work simultaneously to achieve force grasping. The manipulator can choose different grasping methods according to the shape and properties of the actual object, and the grasping methods are diversified; the movable pulley, fixed pulley, wire rope five and wire rope six constitute the under-actuated system structure in the palm, and the T-slot ensures the linear motion of the movable pulley. The under-actuated system structure has a reasonable spatial layout, a stable and firm connection, and a stable and precise control effect.

[0014] The beneficial effects are:

[0015] 1. The present invention adopts a rope-driven under-driven five-finger manipulator with compact structure, light weight, simple control system and low cost. Through the step-by-step and synchronous work of three rotating motors in the palm, three motors can control 11 active degrees of freedom and 4 coupled degrees of freedom, which can complete adaptive grasping and actively adjust the posture to the appropriate position for precise grasping. The operation is light and flexible;

[0016] 2. The rope and pulley in the four-finger assembly work together to couple and drive the distal joint to bend. Multiple motor drives are not required. Each finger has three degrees of freedom and a large working space. It can perform grasping actions in various postures such as clenching, pinching, and side pinching. By adopting a rope-driven rope-pulley system structure, the number of finger drive motors can be reduced without affecting the daily life functions of the manipulator, thereby reducing the manufacturing cost and weight of the manipulator, and compacting the drive components inside the palm, making the fingers themselves lighter and more compact, and moving more smoothly. The tension spring of the under-driven rope-pulley system is connected to the end of the wire rope to prevent excessive motor torque due to excessive contact force, and also plays an auxiliary tensioning role.

[0017] 3. Motor 3 drives the thumb assembly to swing for adaptive grasping. At the same time, motor 3 can drive the thumb assembly to actively adjust to a more suitable posture to adapt to grasping tasks with different requirements.

[0018] 4. Rope is used as the main transmission method to reduce the weight of fingers; the manipulator can choose different grasping methods according to the shape and properties of the actual object, and the grasping methods are diversified; the movable pulley, fixed pulley and wire rope 5 and wire rope 6 constitute the under-actuated system structure in the palm, and the T-slot ensures the linear motion of the movable pulley. The under-actuated system structure has a reasonable spatial layout, a stable and firm connection, and a stable and accurate control effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the manipulator of the present invention;

[0020] Figure 2 It is a front view of the palm structure of the present invention (the front plate of the palm is not drawn);

[0021] Figure 3 It is a right view of the palm structure of the present invention;

[0022] Figure 4 It is a schematic diagram of the index finger structure of the present invention;

[0023] Figure 5 This is a schematic diagram of the cross tendon principle;

[0024] Figure 6 A top view of the thumb structure of the present invention;

[0025] Figure 7 It is a right view of the thumb structure of the present invention;

[0026] Figure 8 It is a schematic diagram of the winding of the steel wire rope of the palm underactuated system;

[0027] Fig. 9 This is a diagram showing the index finger grasping a disc-shaped object. Figure 1 ;

[0028] Fig.10 This is a diagram showing the index finger grasping a disc-shaped object. Figure 2 ;

[0029] Fig.11 Schematic diagram of the process of accurately grasping a disc-shaped object Figure 1 ;

[0030] Fig.12 Schematic diagram of the process of accurately grasping a disc-shaped object Figure 2 .

[0031] Reference numerals:

[0032] 1-palm assembly, 2-four-finger assembly, 3-thumb assembly, 11-palm back plate, 12-palm front plate, 13-threading device, 14-T-slot, 15-first movable pulley, 16-second movable pulley, 17-first fixed pulley, 18-second fixed pulley, 19-wire pressing aluminum sleeve, 110-tension spring 1, 111-tension spring 2, 112-pulley spindle, 113-cross screw m2, 114-long pulley frame, 115-short pulley frame , 116-steering wheel, 117-motor three L-shaped plate, 118-motor three, 119-guide wheel, 120-tension spring three, 121-tension spring four, 122-wire rope six, 123-wire rope five, 124-tension spring six, 125-tension spring five, 126-motor one, 127-motor one L-shaped plate, 128-winding wheel, 129-wire rope groove pressure plate, 130-motor two, 131-motor two L-shaped plate, 21-distal joint rod, 22-axis three, 23-deep groove ball bearing, 24-middle joint; 25-middle joint pulley one, 26-near joint, 27-bolt, 28-washer, 29-nut, 210-double groove pulley one, 211-bearing seat, 212-wire rope two, 213-distal joint pulley one, 214-wire rope four, 215-middle joint pulley two, 216-axis two, 217-wire rope three, 218-near joint pulley one, 21 9-axis one, 220-wire rope one, 31-thumb distal joint rod, 32-deep groove ball bearing, 33-axis two, 34-distal joint pulley two, 35-thumb proximal joint rod, 36-double groove pulley two, 37-bearing seat, 38-guide wheel shaft, 39-wire rope seven, 310-proximal joint pulley two, 311-axis one, 312-wire rope eight, 313-wire rope nine, 314-metacarpal joint plate, 315-guide wheel, 316-connecting plate. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings:

[0034] Embodiment 1:

[0035] See also Figure 1 The rope-driven under-driven five-finger manipulator includes a palm 1, a thumb 3, and the remaining four fingers 2. The thumb has a swingable metacarpal joint and a bendable proximal joint and distal joint. The remaining four fingers have bendable proximal joints, middle joints, and distal joints. The distal joints of the four fingers are coupled driven. The entire manipulator has 11 degrees of freedom and 4 coupled degrees of freedom. Each finger is connected to the palm front plate 12 and the palm rear plate 11 by bolts. Three motors are installed in the palm. Motor 1 126 is used to drive the proximal joints of the five fingers to bend, motor 2 130 is used to drive the middle joints of the four fingers and the distal joint of the thumb to bend, and motor 3 118 is used to drive the thumb metacarpal joint to swing.

[0036] Due to the modular design, the five fingers of the manipulator are divided into a thumb module and the other four finger modules. The present invention has a compact structure and light weight. Three motors control 11 active degrees of freedom and 4 coupled degrees of freedom. It can complete adaptive grasping and active adjustment to a suitable posture. The operation is light and flexible.

[0037] Embodiment 2:

[0038] Example 2 is based on Example 1, see Figure 2 , Figure 3 , which are the front view and right view of the palm structure of the rope-driven under-driven five-finger manipulator, respectively. The motor frame fixing holes of three motors are set on the palm rear plate 11, and the fixing holes of the steering wheel frame are set on the right side. The mounting plate of the four fingers corresponding to the tension spring is welded in the middle, and the mounting plate of the thumb corresponding to the T-slot, movable pulley and fixed pulley is welded at the bottom, and the guide wheel spindles are welded on both sides. The T-slot 14 is directly embedded in the corresponding slot hole on the mounting plate; the first fixed pulley 17 and the second fixed pulley 18 are bolted to the mounting plate through the through hole at the bottom of the pulley frame; the first movable pulley 15 and the second movable pulley 16 are connected to the wire rope 1 220 and the wire rope 2 212 through the threader at the bottom of the pulley frame, and one end of the spindle 12 where the movable pulley is located is embedded in the T-slot to ensure its linear motion; the motor three L-shaped plate 117, the motor one L-shaped plate 127, and the motor two L-shaped plate 131 are bolted to the palm back plate through the motor frame fixing holes on the palm back plate, and the end face is connected to the end face screw of the motor to realize the installation of the motor; the steering wheel 116 is bolted to the palm back plate 11 through the long pulley frame 114 and the short pulley frame 115; the guide wheel 119 is installed on the guide wheel spindle and positioned by a spring washer. The middle of the palm front plate 12 is welded with a mounting plate for the four fingers corresponding to the T-slot, the movable pulley, and the fixed pulley, and the bottom is welded with a mounting plate for the thumb corresponding to the tension spring. The T-slot is directly embedded in the corresponding slot hole on the mounting plate; the first fixed pulley 17 and the second fixed pulley 18 are bolted to the mounting plate through the through hole at the bottom of the pulley frame; the first movable pulley 15 and the second movable pulley 16 are connected to the steel wire rope 8 312 and the steel wire rope 9 313 through the threader at the bottom of the pulley frame, and one end of the mandrel where the movable pulley is located is embedded in the T-slot to ensure its linear motion.

[0039] The movable pulley, fixed pulley and wire rope constitute the under-actuated system structure in the palm. The T-slot ensures the linear motion of the movable pulley. The under-actuated system structure has a reasonable spatial layout, stable and firm connection, and stable and accurate control effect.

[0040] Embodiment 3:

[0041] Example 3 is based on Example 2, see Figure 4, which is a schematic diagram of the index finger structure of the rope-driven under-driven five-finger manipulator. The index finger 2 is fastened to the front and rear plates of the palm through the bearing seat 211; the wire rope 220 passes around the near-joint pulley 218, one end of which is connected to the first movable pulley 15 in the palm through the threader 13, and the other end is connected to the tension spring 110 in the palm through the crimped aluminum sleeve 19, so that the power of the motor 126 is transmitted from the palm to the index finger, and the near-joint bending is realized; the wire rope 212 passes around the near-joint double-groove pulley One end of the first finger 210 is connected to the second movable pulley 16 in the palm through a threader, and the other end is connected to the tension spring 2 111 in the palm through a crimped aluminum sleeve, so that the power of the motor 2 130 is transmitted from the palm to the index finger. The steel wire rope 3 217 passes through the proximal joint double groove wheel 1 210 and the middle joint pulley 1 25 to form a synchronous rope transmission to achieve the bending of the middle joint; the steel wire rope 4 214 is cross-wound between the middle joint pulley 2 215 and the distal joint pulley 1 213 to achieve the coupling bending of the distal joint. The rotation angle range of the three joints is 0~90°.

[0042] The near joint pulley 218 and the shaft 219 have an interference fit, and the near joint 26 and the shaft 1 have an interference fit, so the rotation angle of the near joint pulley 1 is equal to the near joint joint angle θ1; the double groove pulley 210 and the shaft 1 have a clearance fit, the middle joint pulley 25 and the shaft 2 216 have an interference fit, and the middle joint 24 and the shaft 2 have an interference fit, so the rotation angle of the double groove pulley 1 relative to the near joint pulley 1 is equal to the middle joint joint angle, that is, θ2=θ 21 θ1; the middle joint pulley 215 is clearance-matched with the shaft 2, and is fastened to the proximal joint through bolts, that is, the middle joint pulley 2 and the proximal joint are relatively stationary, the distal joint pulley 1 213 and the shaft 3 22 are interference-fitted, and the distal joint rod 21 and the shaft 3 are interference-fitted. Due to the relationship of the cross tendons, the distal joint pulley 1 and the middle joint pulley 2 are transmitted in reverse to realize the coupled bending of the distal joint.

[0043] The rope and pulley in the four-finger assembly work together to couple and drive the distal joint to bend, without the need for multiple motor drives. Each finger has three degrees of freedom and a large working space, and can perform a variety of grasping movements such as tight grip, pinching, and side pinching.

[0044] Embodiment 4:

[0045] Example 4 is based on Example 3, see Figure 5 , is a schematic diagram of the cross tendon principle of the rope-driven under-driven five-finger manipulator. When the proximal joint is taken as the reference, the middle joint pulley 2 is relatively stationary with the proximal joint, so θ2=0°, θ3=0°. In the initial position, the cross tendon contact points are A, B, C, D, and , when the joint rotates θ2, it will cause Since the middle joint pulley 2 is relatively stationary, points C and D remain unchanged. In order to obtain a balanced state, the cross tendon drives the distal joint pulley 1 to rotate so that point A moves to A' and point B moves to B'. , the angle of rotation of the distal joint pulley θ3=θ2. Therefore, the distal joint joint angle θ3=θ2.

[0046] The cross tendon structure is simple and exquisite in design. The double pulley and cross tendon combined structure can make the two distal joints rotate synchronously at the same angle when working.

[0047] Embodiment 5:

[0048] Example 5 is based on Example 4, see Figure 6 , Figure 7 , which are the top view and right view of the thumb structure of the rope-driven under-driven five-finger manipulator. The thumb 3 is fastened with the metacarpal joint 314 by bolts through the bearing seat 37; the metacarpal joint is fastened with bolts to the connecting plate 316, and the output shaft 118 of the motor three is interference fit with the hole of the connecting plate. The rotation angle of the output shaft of the motor three is the swing angle of the metacarpal joint. The steel wire rope 8 312 passes around the proximal joint pulley 2 310, one end of which is connected to the first movable pulley in the palm through a threading device, and the other end is connected to the tension spring 3 120 in the palm through a crimped aluminum sleeve, so that the power of the motor 1 is transmitted from the palm to the thumb, and the proximal joint of the thumb is bent; the steel wire rope 9 313 passes around the proximal joint double groove pulley 2 36, one end of which is connected to the second movable pulley in the palm through a threading device, and the other end is connected to the tension spring 4 121 in the palm through a crimped aluminum sleeve, so that the power of the motor 2 is transmitted from the palm to the thumb, and the steel wire rope 7 39 passes around the proximal joint double groove pulley 2 36 and the distal joint pulley 2 34 to form a synchronous rope transmission, and the distal joint of the thumb is bent. The swing range of the metacarpal joint is -90°~30°. When swinging -90°, the thumb is located on one side of the palm, and the side pinching action can be achieved. The proximal joint angle range is 0°~60°, and the distal joint angle range is 0°~90°.

[0049] The proximal joint pulley 2 310 has an interference fit with the thumb shaft 1 311, and the thumb proximal joint rod 35 has an interference fit with the shaft 1, so the rotation angle of the proximal joint pulley 2 310 is equal to the proximal joint joint angle θ1; the double-groove pulley 2 36 has a clearance fit with the shaft 1, the distal joint pulley 2 34 has an interference fit with the thumb shaft 2 33, and the thumb distal joint rod 31 has an interference fit with the thumb shaft 2, so the rotation angle of the double-groove pulley 2 36 relative to the proximal joint pulley 2 310 is equal to the thumb distal joint joint angle.

[0050] The thumb component only uses motor three to control the three knuckles of the thumb. The thumb can swing to cooperate with the four-finger component for adaptive grasping, and can also actively adjust its posture to a suitable position to cooperate with the four-finger component for grasping.

[0051] Embodiment 6:

[0052] Example 6 is based on Example 5, see Figure 8 , is a schematic diagram of the winding of the wire rope of the palm under-actuated system of the rope-driven under-actuated five-finger manipulator. One end of the wire rope 5 123 is fixed on the winding wheel of the motor 1. The output shaft of the motor 1 is connected with the winding wheel by interference fit. The end plate of the winding wheel is punched with holes to guide the end of the wire rope to extend, and is fixed to the end face through a grooved pressure plate 129; it passes through the five first movable pulleys, the five first fixed pulleys and several guide wheels, and the other end is connected to the high-rigidity tension spring 5 125 on the mounting plate through a crimped aluminum sleeve. The principle of the wire rope 6 122 is the same as that of the wire rope 5. One end is fixed on the winding wheel of the motor 2, passes through the five second movable pulleys and the five second fixed pulleys, and the other end is connected to the tension spring 6 124. When the motor rotates, a tension force T is applied to the wire rope 5 and the wire rope 6, and the movable pulley will be pulled downward with twice the tension 2T. The T-slot ensures the linear motion of the movable pulley, and the movable pulley drives the rotation of each joint pulley when it moves downward.

[0053] The function of stretch spring one, stretch spring two, stretch spring three and stretch spring four is to work together with the movable pulley to drive wire rope one and wire rope two, thereby driving the finger joints to bend. The tension of the stretch spring and the movable pulley is balanced to make the fingers rotate smoothly. The spring provides a limiting effect when the fingers are reset. The joint angle can be calculated by the deformation of the stretch spring; the function of stretch spring five and stretch spring six is ​​to mitigate impact and assist tensioning to prevent the motor from being damaged due to hard contact resulting in excessive contact force.

[0054] When the motor is working, all five fingers rotate in the direction of gripping. When one of the fingers first touches the object, the movable pulley P of the finger m The fingers will not continue to fall, and the posture of the fingers remains unchanged. However, the other movable pulleys will continue to move downward until each finger contacts the object, and then the movement will stop. The five fingers achieve the adaptability of passively adapting to the shape of the object.

[0055] Embodiment 7:

[0056] Example 7 is based on Example 6, see Fig. 9 and Fig.10 , which is a schematic diagram of the analysis of the force grasping and precise grasping of the index finger of the rope-driven under-actuated five-finger manipulator on a disc-shaped object. For a disc-shaped object, force grasping can only be done with the fingertips, which is not stable. If you want to grasp it precisely, you can make the grasping more stable by contacting the knuckles.

[0057] Different grasping methods can be selected according to the shape and properties of the actual object, and the grasping methods of the manipulator can be diversified.

[0058] Embodiment 8:

[0059] Example 8 is based on Example 7, see Fig.11 and Fig.12 , which is the specific implementation process of the rope-driven under-driven five-finger manipulator to accurately grasp a disc-shaped object. First, the motor 1 is driven to make the first movable pulley drop to the maximum extent, and the proximal joint rotates 90° accordingly. At this time, although the middle joint is inconvenient to maintain its posture, it rotates 90° in the opposite direction relative to the proximal joint. Due to the action of the coupling tendon driver, the distal joint also rotates 90° in the opposite direction relative to the middle joint. Then, the motor 1 remains stationary, and P m1 Keep it fixed. Drive motor 2 to pull the second movable pulley, and the middle joint and the distal joint rotate in the grasping direction, and stop moving when they touch the object. According to the placement of the object in this example, the second movable pulley almost moves to the maximum displacement, that is, the middle joint pulley rotates nearly 90°. At this time, the action of pinching is obtained.

[0060] The two drive motors work in coordination to achieve precise grasping of disc-shaped objects, and the grasping action is quick and smooth.

[0061] The above descriptions are merely the principles and preferred examples of the present invention. The present invention may be subjected to various changes and improvements. Any modification, equivalent substitution and improvement of the present invention are included in the protection scope of the present invention.

Claims

1. A rope-driven under-driven five-finger manipulator, characterized in that: The invention comprises a palm assembly (1), a four-finger assembly (2) mounted on the palm assembly, and a thumb assembly (3); the four-finger assembly (2) comprises an index finger, a middle finger, a ring finger and a little finger of the same structure; each finger of the four-finger assembly (2) comprises a proximal joint (26), a middle joint (24) and a distal joint rod (21); the rotation of the proximal joint (26) is driven by a steel wire rope 1 (220) and a tension spring 1 (110); the rotation of the middle joint (24) is driven by a steel wire rope 2 (212), a steel wire rope 3 (217) and a tension spring 2 (111); the distal joint rod realizes coupling drive by relying on the principle of a cross-tendon coupled tendon driver; the thumb assembly (3) comprises a thumb proximal joint rod (35), a thumb distal joint rod (31) and a palm The thumb proximal joint rod is driven to rotate by steel wire eight (312) and tension spring three (120), the thumb distal joint rod is driven to rotate by steel wire nine (313), steel wire seven (39) and tension spring four (121), the metacarpal joint is directly driven by motor three, and when the motor rotates, the metacarpal joint is driven to rotate around the motor axis. The rope-driven under-driven five-finger manipulator can effectively achieve precise grasping; the four-finger assembly (2) is composed of a proximal joint (26), a middle joint (24) and a distal joint rod (21); the steel wire one (220) passes around the proximal joint pulley two and the proximal joint pulley one (218), one end of which is connected to the tension spring one (110), and the other end is connected to the first movable pulley (15) in the palm, the first movable pulley (1 5) linear motion controls the bending of the proximal joint; the second steel wire rope (212) bypasses the proximal joint double groove pulley (210), one end of which is connected to the second tension spring (111), and the other end is connected to the second movable pulley (16) in the palm; the third steel wire rope (217) bypasses the double groove pulley (210) and forms a synchronous transmission with the middle joint pulley (25); the second movable pulley (16) controls the bending of the middle joint by linear motion; the fourth steel wire rope (214) crosses the middle joint pulley (215) and the distal joint pulley (213) to form a cross tendon, so that the proximal joint and the middle joint work together to couple and drive the distal joint to bend; the thumb assembly (3) comprises a metacarpal joint (314), a thumb proximal joint rod (35), a thumb distal joint rod (31), and a motor (3). (118); the output shaft of the motor 3 (118) in the palm is fixedly connected to the metacarpal joint through the connecting plate (316), directly controlling the swing of the metacarpal joint; the steel wire rope 8 (312) passes around the proximal joint pulley 2 (310), one end of which is connected to the tension spring 3 (120), and the other end is connected to the first movable pulley (15) in the palm, and the first movable pulley moves linearly to control the bending of the proximal joint of the thumb; the steel wire rope 9 (313) passes around the proximal joint double-groove pulley 2 (36), one end of which is connected to the tension spring 4 (121), and the other end is connected to the second movable pulley (16) in the palm, and the steel wire rope 7 (39) passes around the double-groove pulley 2 (36) to form a synchronous transmission with the distal joint pulley 2 (34), and the second movable pulley (16) moves linearly to control the bending of the distal joint of the thumb;The palm assembly (1) comprises a palm front plate (12), a palm rear plate (11), a T-shaped groove (14), a first movable pulley (15), a second movable pulley (16), a first fixed pulley (17), a second fixed pulley (18), a steering wheel (116), a steel wire rope, a motor 1 (126), a motor 2 (130), a winding wheel (128), a motor 1 L-shaped plate (127) and a motor 2 L-shaped plate (131); the output shaft of the motor 1 (126) is connected to the winding wheel, one end of the steel wire rope 5 (123) is connected to the winding wheel, passes through the five first fixed pulleys (17) and the five first movable pulleys (18), and the first fixed pulley (17) is connected to the first fixed pulley (18). The pulley (15) has its other end connected to a tension spring (125) to control the linear motion of the five first movable pulleys (15), i.e., the proximal joints of the five fingers are bent; the output shaft of the second motor (130) is connected to the winding wheel, one end of the steel wire rope (122) is connected to the winding wheel, passing through the five second fixed pulleys (18) and the five second movable pulleys (16), and the other end is connected to a tension spring (124) to control the linear motion of the five second movable pulleys (16), i.e., the distal joints of the thumb are bent and the middle joints of the four fingers are bent; the movable pulley, the fixed pulley and the steel wire rope constitute an under-actuated system structure in the palm. ;

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