CN203077298U - Under-actuation five-finger manipulator - Google Patents

Abstract

The utility model relates to an underactuated five-finger manipulator, which belongs to the field of robots. The thumb, index finger, middle finger, ring finger and little finger driven by the side swing motor and the bending motor are fixedly connected with the palm respectively, wherein the thumb, index finger, middle finger, ring finger and little finger have the same structure. Driven by two motors, the functions of side swing, bending and reverse stretching of the fingers are respectively realized. When the side swing motor has power input, the finger can realize the side swing function in the left and right directions when the side swing motor is in the forward and reverse direction. The functions of finger bending and reverse stretching are to drive the rotating shaft with steel wire rope wound by the bending motor, and change the winding length of the steel wire rope on the rotating shaft to realize finger bending and reverse stretching. The advantages are: novel structure, simple and compact, small size, reliable connection of each joint; each finger has 4 degrees of freedom, large range of motion, strong safety, flexible coordinated movement between fingers, wide application range, and low energy consumption .

Description

Underactuated five-finger manipulator

technical field

The utility model relates to the field of robots, in particular to an underactuated five-finger manipulator.

Background technique

The robotic dexterous hand is an intelligent general-purpose manipulator researched and developed for multi-tasking. It is widely used in many fields such as space exploration, nuclear energy development, and medical rehabilitation equipment. With the continuous advancement of the level of science and technology, the research on dexterous hands has gradually become a specialized research field in the field of robotics. The Stanford/JPL hand, Gifu hand, etc., the HIT dexterous hand developed by Harbin Institute of Technology in China, the BH dexterous hand of Beihang University, etc. Taking Gifu hand as an example, it has more degrees of freedom and the number of drivers required. Although it can grasp objects flexibly and autonomously, and has good grasping stability, a large number of The tactile sensor, by increasing the requirements of the control system and sensors to meet the automatic adaptation to the shape and size of the object when grasping, has a high degree of complexity and high cost. Underactuation can overcome some shortcomings of the above-mentioned dexterous hand, and can achieve the purpose of self-adaptive grasping according to the shape and size of the object, reducing the requirements for the sensor and control system of the dexterous hand. The so-called underactuated system refers to a type of nonlinear system in which the number of independent control variables of the system is less than the number of degrees of freedom of the system. It is superior to the fully actuated system in terms of energy saving, cost reduction, weight reduction, and enhanced system flexibility. Simply put, it is a system with less input than the amount to be controlled. The structure of the underactuated system is simple, which is convenient for the overall dynamic analysis and experiment. At the same time, due to the high nonlinearity of the system, parameter perturbation, multi-objective control requirements and limited control quantity, the underactuated system is complex enough to facilitate the research and verification of the effectiveness of various algorithms.

Currently, there are various underactuated dexterous hand patents. For example, the patent CN1231332 mentions an underactuated modular robot multifingered hand, which has 5 fingers, 11 degrees of freedom, and 2 active joints, but its disadvantage is that there are only 2 joints on the thumb, and the other four The reed used on the root joint of the finger takes up a lot of space, which affects the appearance of the finger; the patent CN1292712C mentions an underactuated modular humanoid robot multi-fingered hand with 5 fingers and 14 degrees of freedom, which has 3 active joints, The middle finger, ring finger and little finger adopt modular underactuated joints of connecting rods; patent CN1283429C relates to an underactuated modular anthropomorphic robot multifingered hand with 5 fingers and 12 joint degrees of freedom, and its structural arrangement is similar to the aforementioned patent. However, its underactuated joint is realized by a modular multi-stage gear transmission mechanism with self-dissolving effect. Like the aforementioned patent, its shortcoming lies in the modular structure of the middle finger, ring finger and little finger, so that these three fingers cannot be independent. Rotation, its flexibility is not enough, and the thumb is fixedly installed on the palm of the four fingers directly opposite, and cannot swing back and forth on the side of the palm and directly opposite; patent CN 101804633A mentions a tendon rope underactuated parallel dexterous underactuated bionic robot hand device, the The device has 5 independently controlled fingers and 14 joint degrees of freedom, and is driven by 10 motors. The special effect of combining variable initial configuration of fingers and adaptive grasping is realized comprehensively by using motors, tendon ropes and return springs. However, no mention is made of the sideways function of the fingers.

Contents of the invention

The purpose of the utility model is to provide an underactuated five-finger manipulator, which solves the above-mentioned problems existing in the prior art, and realizes the functions of self-adaptive grasping and independent lateral swing of fingers.

Above-mentioned purpose of the utility model is realized through the following technical solutions:

An under-actuated five-finger manipulator includes a thumb 2, an index finger 3, a middle finger 4, a ring finger 5 and a little finger 6, and is fixedly connected to the palm 1 respectively, and the structures of the thumb 2, the index finger 3, the middle finger 4, the ring finger 5 and the little finger 6 are the same, and There are respectively a finger side swing motor 310 and a bending motor 312. Driven by the two motors respectively, the functions of side swing, bending and reverse stretching of the finger are realized. The functions of finger bending and reverse stretching are driven by the bending motor to drive the wire rope wound The rotating shaft changes the winding length of the wire rope on the rotating shaft to realize finger bending and reverse stretching; the finger side swing motor 310 is fixedly connected with the palm 1 through the side swing motor fixing bracket 309 .

A flat gear I 308 is installed on the output shaft of the side swing motor 310, and another flat gear II 311 meshing with it, the cross joint 305 and the bearing 316 share a side swing rotating shaft 307. When the finger side swing motor 310 has power input, the Under the action of the reducer, the fingers are driven to realize the side swing function.

A flat gear III 313 is also installed on the output shaft of the bending motor 312, and the rotating shaft 314 of another flat gear IV 315 meshing with it passes through the cross joint 305, and one bearing 316 is respectively installed on the upper and lower planes of the cross joint 305. When the bending motor has power input, the bending and reverse stretching of the fingers are realized through the drive of the wire rope.

Each of the thumb 2, index finger 3, middle finger 4, ring finger 5 and little finger 6 is provided with a control pin on each joint finger segment and cross joint, and a wire rope is wound between the position control pin and the rotating shaft passing through the cross joint. The two free ends of the steel wire rope are fixed at the middle positioning hole 501 of the far knuckle of the finger through screws. The pin shaft III 319 rotates to realize the bending and reverse stretching of the fingers.

The end of each far knuckle of described thumb 2, forefinger 3, middle finger 4, ring finger 5 and little finger 6 is provided with a cover 301, and strain gauge pressure sensor is installed on the cover 301, to realize in the process of grasping by finger sensations of different objects. The cover 301 on which the strain gauge pressure sensor is installed may be replaced by a six-dimensional force sensor having the same shape.

In order to make the appearance of the underactuated five-finger manipulator more beautiful, the side baffle is fixedly installed on the positioning hole 402 of the side plate.

The beneficial effect of the utility model is that: compared with the prior art, the utility model has a novel structure, concise and compact, small volume, reliable connection of each joint, steel wire ropes are installed between the control pins between the finger joints, and the transmission relationship is simple and clear; Each finger has the characteristics of 4 degrees of freedom, the finger movement range is large, the safety is strong, the coordinated movement between each finger is flexible, and the application range is wide; the energy consumption required for the function is low, and the 12V power supply is used.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the utility model and constitute a part of the application. The schematic examples and descriptions of the utility model are used to explain the utility model and do not constitute improper limitations to the utility model.

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the structural representation of the palm of the present utility model;

Fig. 3 is the structural representation of the finger of the present utility model;

Fig. 4 is the front view of the far knuckle structure of the utility model;

Fig. 5 is a sectional view of the structure of the far finger joint of the present utility model;

Fig. 6 is the front view of the proximal knuckle structure of the present utility model;

Fig. 7 is the front view of the metacarpal joint structure of the present utility model;

Fig. 8 is the front view of the cross joint structure of the present utility model;

Fig. 9 is a schematic diagram of the winding of the steel wire rope of the present invention, wherein A direction is the winding method of the steel wire rope when the fingers are bent, and B is the winding method of the steel wire rope when the fingers are stretched in the opposite direction;

Fig. 10 is a schematic diagram of direction A of Fig. 9;

FIG. 11 is a schematic view taken along direction B of FIG. 9 .

Figure 12 is a cross-sectional view of the cover attached to the first finger segment.

Fig. 13 is a front view of the structure of the finger side baffle.

Among the figure: 1, palm; 2, thumb; 3, index finger; 4, middle finger; 5, ring finger; 6, little finger; 201, finger side swing motor frame fixing hole; Far finger joint; 303, proximal finger joint; 304, metacarpal joint; 305, cross joint; 306, bending motor fixing frame; 307, side swing rotating shaft; 308, flat gear I; 309, side swing motor fixing frame; 310, Finger side swing motor; 311, spur gear II; 312, finger bending motor; 313, spur gear III; 314, rotating shaft with wire rope; 315, spur gear IV; 316, bearing; 317, pin shaft I; 318, Pin shaft II; 319, pin shaft III; 401, positioning hole I; 402, side baffle positioning hole; 501, positioning hole in the middle of the distal finger joint; 601, positioning hole II; 701, positioning hole III; 801, Control hole IV.

Detailed ways

Further illustrate the detailed content of the utility model and its specific implementation below in conjunction with accompanying drawing.

Referring to Fig. 1, the underactuated five-finger manipulator of the present invention includes a palm 1, a thumb 2, an index finger 3, a middle finger 4, a ring finger 5, and a little finger 6, wherein each finger has 3 joints and 4 degrees of freedom, and the whole manipulator There are 20 degrees of freedom in total, and each finger is fixedly connected with the palm 1 through a cross joint. On the back of the palm 1, two motors are configured for each finger, one motor is used for bending and reverse stretching of the finger (bending motor), and the other motor is used for realizing the side swing function of the finger (side swing motor). In view of the consistent structure of each finger, the following only uses the index finger as an example for structural description.

2, palm 1 is respectively provided with thumb, forefinger, middle finger, ring finger and little finger finger side swing motor frame fixing hole 201, and finger rotation positioning hole 202, and bearing 316 is installed in finger rotation positioning hole 202.

Referring to Fig. 3, the index finger side swing motor 310 is fixed to the fixing hole 201 on the palm 1 through the fixing frame 309, and the whole finger is fixedly connected with the palm, and a flat gear I 308 is installed on the output shaft of the finger side swing motor 310, A bearing 316 is installed at the finger rotation positioning hole 202, and the side swing rotating shaft 307 passing through the bearing connects the palm 1, the cross joint 305, and the spur gear II 311 together, and the spur gear I 308 on the motor output shaft is in phase with the spur gear II 311. Mesh, two spur gears constitute a reduction mechanism. When the motor has power input, the motor makes the entire finger swing sideways relative to the palm under the action of the bearing through the horizontal gear reduction mechanism, so as to realize the sideway function of the finger.

The bending motor 312 used for finger bending is fixed on the cross joint 305 through the bending motor fixing frame 306, and a flat gear III 313 is also installed on the output shaft of the bending motor, and a bearing 316 is respectively installed on the upper and lower planes of the cross joint 305 A spur gear Ⅳ 315 is installed on the rotating shaft 314 that passes through 2 bearings and is wound around a steel wire rope. The spur gear Ⅳ 315 is meshed with the spur gear Ⅲ 313 on the output shaft of the motor to form a speed reduction mechanism. The function of finger bending and reverse stretching is that the bending motor 312 drives the rotating shaft 314 around which the wire rope is wound, and the length of the wire rope on the rotating shaft is changed to realize finger bending and reverse stretching. When the bending motor rotates forward, the finger bending is realized. Action, on the contrary, when the bending motor reverses, the reverse stretching action of the finger is realized.

Referring to Fig. 3, Fig. 4 to Fig. 13, the finger has 3 joints in total, and 3 finger segments, which are respectively the far knuckle 302, the proximal knuckle 303, and the metacarpal joint 304, and a cover is installed at the end of the far knuckle 302 301, the cover 301 is mainly used to install the strain-type pressure sensor, so as to realize the force of grasping the object when the finger is bent to grasp the object, so as to adapt to the grasping of different objects. The cover 301 equipped with the strain-type pressure sensor can be made of A six-dimensional force sensor of the same shape is used instead. The three finger segments are connected by pin shafts, which are respectively pin shafts I, II, III 317, 318, and 319. Under the action of the wire rope, the three finger segments can rotate around their respective pin shafts, thereby realizing the bending of the fingers and reverse stretch. In order to make the wire rope pass through each finger segment and connect the 3 finger segments by winding the wire rope, position control holes are respectively set on the far knuckle 302, the proximal knuckle 303, the metacarpal joint 304, and the cross joint 305. Two pairs of position control holes IV801 are set on the cross joint 305, two pairs of position control holes 401I are set on the distal finger joint 302, four pairs of position control holes II601 are set on the proximal finger joint 303, and four pairs of position control holes III701 are set on the metacarpal joint 304 , a positioning pin is installed between each pair of positioning holes, and the wire rope is wound on the positioning pin. Pass through the rotating shaft 316 of 2 bearings, and a wire rope is wound around the positioning pin, and the two free ends of the wire rope after winding are fixed in the middle positioning hole 501 of the far knuckle at the top of the far knuckle 302 by screws , the position control pins of the three joints of the finger and the rotating shaft of the rope form a loop. When the bending motor 312 used for finger bending has power input, the rotating shaft rotates under the action of the reduction gear, changing the position of the wire rope on the rotating shaft. The length of the winding varies to achieve the bending or reverse extension of the fingers.

A wire rope is wound between the finger segment, the cross joint and the rotating shaft passing through the cross joint, and the two free ends of the wire rope are fixed on the middle positioning hole 501 of the far knuckle of the finger. When the motor has power input, under the drive of the reducer, the rotating shaft 314 with the wire rope rotates, changing the rotation length on the shaft, and then changing the length of the wire rope between the position control pins, so that the distance between the position control pins The angle changes, which in turn will change the degree of bending and reverse stretching of the finger, and realize the bending and reverse stretching of the finger.

Compared to other underactuated manipulators, the number of wire ropes per finger is reduced to 1.

Thumb 2, index finger 3, middle finger 4, ring finger 5 and little finger 6 driven by finger side swing motor 310 and bending motor 312 are respectively fixedly connected to palm 1 through the fixing frame of finger side swing motor, driven by two motors, respectively Realize the side swinging and bending functions of the fingers. The finger bending function is realized by driving the wire rope through the bending motor 312. The thumb 2, index finger 3, middle finger 4, ring finger 5 and little finger 6 have the same structure.

A flat gear I 308 is installed on the output shaft of the finger side swing motor 310, and another flat gear II 311 meshing with it, the cross joint 305 and the bearing share a side swing rotating shaft 307. Under the action of driving the fingers to realize the side swing function.

A flat gear III 313 is also installed on the output shaft of the bending motor 312 of the finger, and the rotating shaft 314 of another flat gear IV 315 meshed with it passes through the cross joint 305, and a bearing 316 is installed on the cross joint 305. When the motor has power input, through The driving of the wire rope realizes the bending and reverse stretching of the fingers. Position control pins are arranged on each finger section of the finger and the cross joint 305, and a steel wire rope is wound between the position control pin and the rotation shaft passing through the cross joint, and the two free ends of the steel rope are fixed on the far knuckle of the finger by screws. The center positioning hole 501. When the finger segment is bent, the bending and reverse extension of the finger can be realized by changing the length of the wire rope between the control pins.

A cover 301 is provided at the end of the far knuckle 302 of the finger, and a strain gauge pressure sensor is installed on the cover 301 to realize the sensation of different objects during the finger grasping process. The cover 301 that is equipped with a strain gauge pressure sensor can be made of A six-dimensional force sensor of the same shape is used instead.

When the finger side swing motor 310 has power input, the finger starts to swing sideways, and the angle range of the side swing is -20° to 20°. In the bending action, firstly, the metacarpal joint 304 begins to bend. The range of the joint bending angle of the metacarpal joint 304 is -20° to 90°. When the angle is adjusted, the far finger joint 302 starts to bend, and the joint bending angles of the proximal finger joint 303 and the metacarpal joint 304 are respectively 0° to 90°.

The above descriptions are only preferred examples of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made to the utility model shall be included in the protection scope of the utility model.

Claims (6)

1. An underactuated five-finger manipulator, comprising thumb (2), index finger (3), middle finger (4), ring finger (5) and little finger (6), and fixedly connected with palm (1) respectively, characterized in that: The structures of the thumb (2), index finger (3), middle finger (4), ring finger (5) and little finger (6) are the same, and have finger side swing motors (310) and bending motors (312) respectively. Driven by the motor, the functions of lateral swing, bending and reverse stretching of the finger are realized; the finger lateral swing motor (310) is fixedly connected with the palm (1) through the fixing bracket (309), and the finger bending motor ( 312) are fixedly connected with the cross joint (305) through the fixing frame (306). 2. The underactuated five-finger manipulator according to claim 1, characterized in that: a spur gear I (308) is installed on the output shaft of the side swing motor (310), and another spur gear II (311) meshing with it, The cross joint (305) and the bearing (316) share a side swing rotating shaft (307). When the finger side swing motor (310) has power input, it drives the finger under the action of the reducer to realize the side swing function. 3. The underactuated five-finger manipulator according to claim 1, characterized in that: a spur gear III (313) is also installed on the output shaft of the bending motor (312), and another spur gear IV (315) meshing with it The rotating shaft (314) around which the wire rope passes through the cross joint (305), and the bearing (316) is installed on the cross joint (305). When the motor has power input, the bending and reverse stretching of the finger can be realized through the driving of the wire rope Function; the function of finger bending and reverse stretching is to change the winding length of the wire rope on the rotating shaft through the bending motor to drive the rotating shaft around the rotating shaft to realize finger bending and reverse stretching. Bending action, otherwise when the bending motor reverses, the reverse stretching action of the finger is realized. 4. The underactuated five-fingered manipulator according to claim 1, characterized in that: each joint finger of the thumb (2), index finger (3), middle finger (4), ring finger (5) and little finger (6) Both the segment and the cross joint (305) are provided with position control pins, and a steel wire rope is wound between the position control pin and the rotating shaft passing through the cross joint, and the two free ends of the steel rope are fixed at the middle positioning hole of the far knuckle of the finger through screws (501), the bending and reverse stretching of the finger segment is realized by winding the length on the rotation axis. 5. The underactuated five-finger manipulator according to claim 1, characterized in that each finger of the thumb (2), index finger (3), middle finger (4), ring finger (5) and little finger (6) is far A cover (301) is provided at the end of the knuckle, and a strain gauge pressure sensor is installed on the cover (301), so as to realize the sensation of different objects during the finger grasping process. 6. The underactuated five-finger manipulator according to claim 5, characterized in that: the cover (301) on which the strain gauge pressure sensor is installed is a six-dimensional force sensor with the same shape.

Images