CN113146667A

CN113146667A - Single-or double-knuckle contact flexible manipulator and grasping method thereof

Info

Publication number: CN113146667A
Application number: CN202110473878.7A
Authority: CN
Inventors: 章军; 刘禹; 章立; 陈彦秋; 吕兵
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2021-04-29
Filing date: 2021-04-29
Publication date: 2021-07-23
Anticipated expiration: 2041-04-29
Also published as: CN113146667B

Abstract

The invention discloses a single-or double-knuckle contact flexible manipulator, wherein a palm part comprises a driving source, a bottom plate and a movable push plate, the driving source is arranged on the bottom plate, and the movable push plate is arranged at the free end of the driving source; the finger part comprises a two-force rod, a bent rod knuckle, a middle knuckle and a fingertip knuckle which are sequentially hinged, the middle part of the bent rod knuckle is hinged on the bottom plate, the other end of the two-force rod is hinged on the movable push plate, and a torsion piece for enabling the middle knuckle and/or the fingertip knuckle to be bent inwards is arranged at least one position between the bent rod knuckle and the middle knuckle and between the middle knuckle and the fingertip knuckle. A grasping method of a single or double-knuckle contact flexible manipulator is characterized in that angles between finger tip sections and finger middle sections of all finger parts are manually or automatically driven and adjusted in advance, and objects to be grasped are grasped by adopting a pinching mode or an enveloping grasping mode. The gripping device can be used for pinching or enveloping and grabbing, and is good in adaptability, strong in universality, simple in structure, low in cost and convenient to control.

Description

Single-or double-knuckle contact flexible manipulator and grasping method thereof

Technical Field

The invention relates to the technical field of robots and automation application, in particular to a fingertip pre-adjusting and finger root driving single or double knuckle contact gripping method and a flexible manipulator, which can be used in the industries of agricultural product picking, food sorting and conveying, industrial product feeding and discharging gripping, commodity logistics packaging and the like. The invention also relates to a grasping method of the single or double knuckle contact flexible manipulator.

Background

The under-actuated manipulator is a multi-knuckle manipulator with the number of actuating elements smaller than the number of degrees of freedom, and is widely applied due to the fact that the number of the actuating elements is small, the grabbing range is wide, the control is simple, the output is large, and the load capacity is good.

At present, one of the finger root joints of the under-actuated manipulator is actively driven; the two under-actuated joints and the active joint have a correlation relationship, namely the angle of the under-actuated joint is always influenced by the angle of the active joint and cannot be influenced by the appearance of a target object, so that the state judgment and the posture analysis are complex, and the robot control is difficult to change in a self-adaptive manner according to the actual state; in particular, the position and magnitude of the contact force of each knuckle is determined by the size of the target object and the position of the target object relative to the manipulator.

Disclosure of Invention

The invention aims to solve the technical problem of providing a single-knuckle or double-knuckle contact flexible manipulator and a grasping method thereof, which can perform pinching or enveloping grabbing through reasonable structural design, and have the advantages of good adaptability, strong universality, simple structure, low cost and convenience in control.

In order to solve the technical problem, the invention provides a single-or double-knuckle contact flexible manipulator which comprises a palm part and at least two groups of finger parts; the palm part comprises a driving source, a bottom plate and a movable push plate, the driving source is arranged on the bottom plate, and the movable push plate is arranged at the free end of the driving source; the finger part comprises a two-force rod, a bent rod knuckle, a middle knuckle and a fingertip knuckle which are sequentially hinged, the middle part of the bent rod knuckle is hinged on the bottom plate, the other end of the two-force rod is hinged on the movable push plate, and a torsion piece for enabling the middle knuckle and/or the fingertip knuckle to be bent inwards is arranged at least one position between the bent rod knuckle and the middle knuckle and between the middle knuckle and the fingertip knuckle.

In a preferred embodiment of the present invention, the torsion member is a torsion spring.

In a preferred embodiment of the present invention, the middle finger section and the curved finger base section are provided with holes, the holes are provided with thick pin shafts, the thick pin shafts are internally provided with cotter pins in a penetrating manner, the torsion spring is sleeved on the thick pin shafts, and two spring wires of the torsion spring respectively abut against and push against the middle finger section and the curved finger base section.

In a preferred embodiment of the present invention, the bending rod further comprises a narrow inclined groove formed on the root section of the bending rod, and one of the spring wires of the torsion spring is located in the narrow inclined groove.

In a preferred embodiment of the present invention, the finger tip joint further comprises a hole, a screw head pin shaft is tightly arranged in the hole, the finger middle joint is provided with a taper hole, an external taper sleeve is arranged in the taper hole, two ends of the screw head pin shaft are provided with threads, and a nut is sleeved on the threads.

In a preferred embodiment of the present invention, the driving source is a cylinder with displacement feedback or a screw shaft motor with feedback.

In a preferred embodiment of the present invention, the base plate is further provided with a forward and backward output mechanism, two output shafts of the forward and backward output mechanism are respectively provided with a grooved pulley, a hinge joint of the finger tip section and the finger middle section is provided with a series connection torsion spring, and a rope is arranged between the finger tip section and the grooved pulley.

In a preferred embodiment of the present invention, the base plate is further provided with a forward and backward output mechanism, two output shafts of the forward and backward output mechanism are respectively provided with a transition sleeve, the finger tip section and the finger middle section are hinged through a taper hole pin shaft, and a flexible shaft is arranged between the transition sleeve and the taper hole pin shaft.

In a preferred embodiment of the present invention, the positive and negative output mechanism is a single-worm double-worm gear positive and negative output shaft mechanism.

A method of gripping a single or double knuckle contact flexible manipulator comprising the steps of using a finger portion comprising three knuckles. The three knuckles are a fingertip knuckle, a middle finger knuckle and a root finger knuckle respectively, the fingertip joints, the middle finger joints and the root finger joints of the fingers are all in single degree of freedom and are on the same plane, the fingertip joints are pre-adjusted, the middle finger joints are non-driven flexible joints, and the root finger joints are automatically driven to clamp objects to be grabbed with different sizes; the angle between the fingertip joint and the middle finger joint of each finger part is manually or automatically driven and adjusted in advance, then the base finger joint is automatically driven to rotate and clamp, when the contact surface of an object to be grabbed is a plane, the fingertip joint and/or the middle finger joint are in parallel contact with the plane of the object to be grabbed in the final grabbing pose, and the grabbing mode is adopted; when the contact surface of the object to be grabbed is a curved surface, in the final grabbing pose, the finger tip section or the finger middle section is in tangential contact with the curved surface in contact with the object to be grabbed in a pinching mode, or the finger tip section and the finger middle section are in tangential contact with the curved surface in contact with the object to be grabbed simultaneously in an enveloping grabbing mode.

The invention has the beneficial effects that:

according to the single-knuckle or double-knuckle contact flexible manipulator and the grasping method thereof, the driving source is designed to drive the movable push plate to linearly displace, so that the two-force rod pulls the knuckle of the bent rod to rotate; when the root section of the bent rod finger rotates, the middle section of the finger and the fingertip section approach to the object to be grabbed simultaneously; when the finger center or the finger tip joint contacts the object to be grabbed, the torque of the torsion piece is overcome until the final grabbing pose is reached, and the driving source stops driving to firmly grab the object to be grabbed. The under-actuated mode and the flexible joint mode are adopted, so that the object to be grabbed can be grabbed quickly and stably, and the object to be grabbed cannot be damaged. The degree of flexibility of the flexible joint can be determined by selecting the spring force of the torsion member. According to the passive grabbing mode, grabbing modes such as pinching and enveloping grabbing can be selected by adjusting the angle between the middle finger section and the finger tip section, the universality is strong, the applicability is good, the structure is simple, the cost is low, especially, the enveloping grabbing reliability of curved surface contact is high, and the finger tip section is adjusted in advance and then the finger root section is driven to clamp and control conveniently.

Drawings

FIG. 1 is a schematic cross-sectional view of a single or dual knuckle contact compliant robot in accordance with an embodiment of the present invention;

FIG. 2 is an enlarged view of a portion of the cross-section taken along line A-A in accordance with one embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a step in the direction B-B according to one embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of a mid-flat hinge base according to an embodiment of the present invention;

FIG. 5 is a schematic top view of a flat hinge base according to one embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of a crowned hinge base in accordance with an embodiment of the present invention;

FIG. 7 is a schematic top view of a crowned hinge base in accordance with an embodiment of the present invention;

FIG. 8 is a schematic cross-sectional view of a root segment C-C of a curved finger according to an embodiment of the present invention;

FIG. 9 is a partial view of the D-direction of the knuckle of a curved bar according to an embodiment of the present invention;

FIG. 10 is a schematic front view of a middle rear finger section according to an embodiment of the present invention;

FIG. 11 is a left side view of a middle section of a middle finger according to an embodiment of the present invention;

FIG. 12 is a schematic cross-sectional view of a knuckle of a finger according to an embodiment of the present invention;

FIG. 13 is a left side view of a knuckle according to an embodiment of the present invention;

FIG. 14 is a schematic view, partially in section, of a single or dual knuckle contact compliant robot in accordance with a second embodiment of the present invention;

FIG. 15 is a schematic cross-sectional view of a single-or double-knuckle contact flexible manipulator in a step E-E direction according to a third embodiment of the present invention;

FIG. 16 is a schematic top view of a single or dual knuckle contact compliant robot in accordance with a third embodiment of the present invention;

FIG. 17 is an enlarged, fragmentary, cross-sectional view of the finger portion in the third embodiment of the present invention in the direction F-F;

FIG. 18 is an enlarged, partial cross-sectional view of the finger portion in the third embodiment of the present invention in the direction of G-G;

FIG. 19 is a schematic left side view of a series torsion spring in accordance with a third embodiment of the present invention;

FIG. 20 is a schematic front view of a series torsion spring in accordance with a third embodiment of the present invention;

FIG. 21 is a schematic cross-sectional view of the series torsion spring in the direction H-H in the third embodiment of the present invention;

FIG. 22 is a schematic cross-sectional view of a single or double knuckle contact compliant robot in accordance with a fourth embodiment of the present invention;

FIG. 23 is a cross-sectional view of a flexible shaft assembly in accordance with a fourth embodiment of the present invention;

FIG. 24 is a schematic cross-sectional view of a fourth example transition piece according to the present invention;

FIG. 25 is an enlarged view of a portion of a finger portion I-I of a fourth embodiment of the present invention;

FIG. 26 is a schematic enlarged view of a portion of a finger portion in the direction of J according to a fourth embodiment of the present invention;

fig. 27 is an enlarged schematic view of a taper hole pin shaft in the fourth embodiment of the present invention;

FIG. 28 is a schematic cross-sectional view of a fifth embodiment of the invention, showing a motor with a single worm and double worm gears, along the K-K direction, of the positive and negative output shaft mechanism;

FIG. 29 is a schematic sectional view of the fifth embodiment of the present invention, taken along the L-L direction, showing a single-worm and double-worm gear positive and negative output shaft mechanism of the motor;

FIG. 30 is a schematic front view of a single-worm double-worm-wheel positive and negative output shaft mechanism of a motor according to a fifth embodiment of the present invention;

FIG. 31 is a schematic top view of a single-worm double-worm-wheel positive and negative output shaft mechanism of a fifth embodiment of the present invention;

FIG. 32 is a diagram illustrating initial state and pose change of a rectangular parallelepiped grasped by a single or double knuckle contact flexible manipulator in a preferred embodiment of the present invention;

FIG. 33 is a diagram illustrating initial state and pose changes of a single or double knuckle contact flexible manipulator grasping a sphere and horizontally placing a cylinder according to a preferred embodiment of the present invention;

FIG. 34 is a final pose diagram of a single or double knuckle contact flexible manipulator grasping a large and small cuboid in the preferred embodiment of the invention;

FIG. 35 is a final pose diagram of the single or double knuckle contact flexible manipulator grasping large and small spheres and large and small horizontally placed cylinders in the preferred embodiment of the present invention.

The reference numbers in the figures illustrate:

1. a drive source; 1a, a screw shaft motor; 1b, a screw nut; 2. a base plate; 3. moving the push plate; 4. a linear bearing; 5. a stud guide rod; 6. mounting a plate; 7. a flat hinge base; 8. a second force lever; 9. a high hinge mount; 10. a curved-bar knuckle; 11. a pin shaft is thickened; 12. a torsion spring; 13. a cotter pin; 14. the back of the taper hole refers to the middle section; 14a, a round hole indicates a middle section; 15. a taper hole front finger middle section; 15a, a round hole front finger middle section; 16. an outer taper sleeve; 17. a threaded head pin shaft; 17a, a thin pin shaft; 17b, a taper hole pin shaft; 18. a fingertip section; 19. a wear-resistant round pad; 20. a positive and negative output mechanism; 21. a skewed grooved sheave; 22. a rope; 23. an L-shaped plate; 24. a cable guide pulley; 25. a small guide wheel shaft; 26. a guide wheel bracket; 27. a fine torsion spring is connected in series; 28. a stop pin; 29. a transition sleeve; 30. a flexible shaft; 31. knurling a threaded sleeve; 32. a conical rolling head;

20a, a motor; 20b, half flange upper cover; 20c, a half-flange base; 20d, a coupler; 20e, worm shaft end cap; 20f, a small bearing; 20g, worm wheel shaft; 20h, rotating the worm wheel rightwards; 20i, a bidirectional worm shaft; 20j, left-hand worm gear; 20k, small key; 20l of worm shaft sealing cover; 20m, a sleeve; 20n, large bearing; 20o, worm gear sealing cover; 20p and a worm gear end cover.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Example one

The embodiment discloses a single or double-knuckle contact flexible manipulator, which is shown in fig. 1-3 and comprises a palm part and at least two groups of finger parts. The palm portion includes a driving source 1, a base plate 2, and a moving push plate 3. The drive source 1 is provided on the base plate 2. A moving push plate 3 is provided at the free end of the drive source 1. The finger part comprises a two-force rod 8, a bent rod finger root section 10, a finger middle section and a finger tip section 18 which are hinged in sequence. The middle part of the curved-rod knuckle 10 is hinged on the bottom plate 2. The other end of the two-force rod 8 is hinged on the movable push plate 3. Torsion pieces for bending the middle knuckle and/or the fingertip knuckle 18 are arranged at least one position between the root knuckle 10 and the middle knuckle and between the middle knuckle and the fingertip knuckle 18. With the optimized design, the driving source 1 can drive the movable push plate 3 to linearly displace, so that the two-force rod 8 pulls the curved-rod knuckle 10 to rotate; when the root section 10 of the curved-bar finger rotates, the middle section of the finger and the fingertip section 18 approach to the object to be grabbed simultaneously; when the finger center or the finger tip joint 18 contacts the object to be grabbed, the torque of the torsion piece is overcome until the final grabbing pose is reached, and the driving source 1 stops driving to firmly grab the object to be grabbed. The under-actuated mode and the flexible joint mode are adopted, so that the object to be grabbed can be grabbed quickly and stably, and the object to be grabbed cannot be damaged. The degree of flexibility of the flexible joint can be determined by selecting the spring force of the torsion member. The passive grabbing mode can select grabbing modes such as pinching, enveloping and grabbing and the like by adjusting the angle between the middle finger section and the fingertip section 18, and has strong universality and good applicability.

Specifically, as shown in fig. 1 and 3, the palm portion includes a mounting plate 6. The mounting plate 6 is positioned and fixed with the mechanical arm. The bottom plate 2 and the mounting plate 6 are connected into a whole by at least two stud guides 5 and nuts twice as many as the stud guides 5. The cylindrical parts at the two ends of the stud guide rod 5 are in clearance fit with the bottom plate 2 and the mounting plate 6 respectively. The drive source 1 is fixed to the base plate 2. A moving push plate 3 is provided at the free end of the drive source 1. At least two linear bearings 4 are fixed on the moving push plate 3. Each stud guide 5 passes through a linear bearing 4. The driving source 1 drives the movable push plate 3 to move linearly under the guidance of the linear bearing 4 and the stud guide rod 5; the movable push plate 3 is provided with a flat hinge base 7 at least at the left and right sides. The flat hinge base 7 is hinged with the two-force rod 8.

Specifically, the finger part may include: the device comprises a bent rod finger root section 10, a thick pin shaft 11, a torsion spring 12, a split pin 13, a taper hole rear finger middle section 14, a taper hole front finger middle section 15, an outer taper sleeve 16, a threaded head pin shaft 17, a fingertip section 18 and a wear-resistant round gasket 19.

Referring to fig. 4 and 5, the flat hinge base 7 and the two-force rod 8 may be hinged in a specific manner by providing two lugs on the flat hinge base 7. The end of the two-force rod 8 is provided with a single ear. The two ears of the flat hinge seat 7 and one single ear of the two-force rod 8 are hinged through a cylindrical pin.

As shown in fig. 1 to 3 and 6 to 9, the base 2 is provided with a high hinge base 9. The high hinge base 9 is provided with two lugs. Two ears are arranged at two ends of the knuckle 10. The knuckle 10 is hinged with the two ears of the high hinge base 9 at the corner position through cylindrical pins. The other single ear of the two-force rod 8 is hinged with one double ear of the knuckle 10 of the bent rod through a cylindrical pin.

Referring to fig. 2, 10 and 11, the middle finger section includes a rear middle finger section 14 and a front middle finger section 15, which are mirror images of each other. The end parts of the taper hole rear finger middle section 14 and the taper hole front finger middle section 15 are provided with holes. The taper hole rear middle finger joint 14 and the taper hole front middle finger joint 15 are respectively positioned on the outer sides of two ears of the bent rod finger root joint 10 and are hinged through a thick pin shaft 11. A cotter pin 13 is inserted into the thick pin shaft 11 to limit axial movement. And wear-resistant round gaskets 19 are arranged on the outer sides of the taper hole rear finger middle section 14 and the taper hole front finger middle section 15 on the cotter 13. The outer sides of the two ears of the knuckle 10 are in clearance fit with the inner sides of the taper hole rear middle knuckle 14 and the taper hole front middle knuckle 15.

The torsion member may be a torsion spring 12. The torsion spring 12 is sleeved on the thick pin shaft 11 and is positioned at the inner side of two ears of the bent rod knuckle 10. The inner sides of the two ears of the knuckle 10 are provided with oblique narrow grooves. One of the torsion springs 12 is pushed against the narrow inclined groove, and the other spring is repaired on the upper bottom surface of the middle finger section 14 behind the taper hole. The pre-tightening torsion spring 12 enables the middle knuckle to bend inwards, and the lower planes of the two ears of the bent-rod knuckle 10 are respectively contacted with the inclined planes on the bottom surfaces of the conical-hole rear middle knuckle 14 and the conical-hole front middle knuckle 15 to perform pre-tightening limiting. When the torsion spring 12 with different force is required to be replaced, the cotter pin 13 can be detached, the thick pin shaft 11 can be pulled out, the applicable torsion spring 12 can be replaced, and the requirement for grabbing contact force is met.

The outer width of the two ears of the bent rod knuckle 10 is equal to the outer width of the U-shaped side wall of the fingertip knuckle 18, and the rear knuckle 14 of the taper hole and the front knuckle 15 of the taper hole are positioned through the thick pin shaft 11, the threaded head pin shaft 17 and the two outer taper sleeves 16 and are combined into the knuckle. The structure is compact and the use is reliable.

Referring to fig. 12 and 13, in some preferred embodiments of the invention, no twist is provided between the knuckle and the fingertip knuckle 18, and the angle between the knuckle and the fingertip knuckle 18 is manually pre-adjusted. At this time, the concrete structure is as follows: the cross section of the pointed tip section 18 is U-shaped. The finger tip joint 18 is provided with a hole. The threaded head pin shaft 17 is arranged in the hole in an interference mode, or the threaded head pin shaft 17 is bonded into the hole through super glue and is integrated with the fingertip joint 18. The finger tip joint 18 can be rotated by rotating the screw head pin shaft 17. The taper hole rear middle finger section 14 and the taper hole front middle finger section 15 are arranged on the outer side of the fingertip section 18. Taper holes are formed in the outer side walls of the taper hole rear finger middle section 14 and the taper hole front finger middle section 15. An outer taper sleeve 16 is arranged in the taper hole. Both ends of the screw head pin shaft 17 are provided with screw threads. The screw thread is sleeved with a nut. The nut is loosened, namely the angle between the finger tip section 18 and the finger middle section can be manually adjusted through the shape of the object to be grabbed; after the angle adjustment is finished, the nut is screwed down, and the electric heating cooker can be put into use.

The drive source 1 may be a cylinder with displacement feedback.

Example two

The present embodiment discloses a single or double knuckle contact flexible manipulator, which is shown in fig. 14, and the structure is consistent with the present embodiment, except that the driving source 1 is a screw shaft motor 1a with feedback. The screw shaft motor 1a is fixed to the base plate 2. The movable push plate 3 is provided with a screw nut 1b, and a screw of a screw shaft motor 1a is arranged in the screw nut 1b in a penetrating manner. The precision of the driving moving push plate 3 is high.

EXAMPLE III

The embodiment discloses a single or double finger joint contact flexible manipulator, which is shown in fig. 15 and 16, and is added with a structure for automatically adjusting the angle between a finger tip joint 18 and a finger middle joint on the basis of the first embodiment, wherein the structure comprises a positive and negative output mechanism 20, an inclined groove rope pulley 21, a rope 22, an L-shaped plate 23, a rope guide pulley 24, a guide pulley small shaft 25, a guide pulley bracket 26, a series connection fine torsion spring 27 and a stop pin 28. And the taper hole rear finger middle section 14 and the taper hole front finger middle section 15 are respectively replaced by a round hole rear finger middle section 14a and a round hole rear finger middle section 15a, and the threaded head pin shaft 17 is replaced by a thin pin shaft 17 a.

The forward/reverse output mechanism 20 is fixed to the outer side of the long side of the L-shaped plate 23. The short sides of the L-shaped plate 23 are fixed to the base plate 2 by screws. Inclined groove rope wheels 21 are mounted on two output shafts of the positive and negative output mechanism 20, are axially fixed through screws and gaskets, and transmit torque through flat keys. One end of the rope 22 is axially fixed on the inclined groove rope wheel 21 through a conical head set screw and winds in the inclined groove, and the other end of the rope 22 penetrates through a double-lug gap of the high hinge seat 9.

Referring to fig. 17 and 18, a guide pulley stub axle 25 passes through the cable guide pulley 24, and the guide pulley stub axle 25 provides support for a guide pulley bracket 26. Two idler brackets 26 are fixed on the side walls of the round hole rear finger middle section 14a and the round hole front finger middle section 15a respectively through screws. The thin pin shaft 17a is in clearance fit with the round hole rear finger middle section 14a and the round hole front finger middle section 15a respectively and is axially fixed through an opening pin shaft. The thin pin shaft 17a and the fingertip joint 18 are in interference fit or are bonded into a whole by strong glue. The series torsion spring 27 is sleeved on the thin pin shaft 17 a. The side wall of the round hole rear middle finger section 14a and the side wall of the fingertip section 18 are both provided with a stop pin 28 in an interference fit manner. The two spring wires of the series torsion spring 27 are retained by two stop pins 28. The other end of the cable 22 is passed through the groove on the outer side of the cable guide 24, and finally wound around the pin shaft 17a and fixed thereto. The rope 22 pulls the thin pin shaft 17a to rotate, thereby overcoming the torque of the series thin torsion spring 27 and driving the finger tip section 18 to rotate towards the inward direction of the object to be grabbed. The motor of the positive and negative output mechanism 20 rotates reversely, and the finger tip joint 18 rotates reversely and resets through the series connection torsion spring 27.

The positive and negative output mechanism 20 may be a single-worm and double-worm gear positive and negative output mechanism.

Example four

The embodiment discloses a single-or double-knuckle contact flexible manipulator, which is added with a structure for automatically adjusting the angle between a knuckle 18 and a middle knuckle on the basis of the first embodiment, and comprises a positive and negative output mechanism 20, an L-shaped plate 23, a guide wheel small shaft 25, a guide wheel bracket 26, a transition sleeve 29, a flexible shaft 30, a knurled threaded sleeve 31 and a conical rolling head 32, as shown in fig. 22-27. And the taper hole rear finger middle section 14 and the taper hole front finger middle section 15 are respectively replaced by a round hole rear finger middle section 14a and a round hole rear finger middle section 15a, and the threaded head pin shaft 17 is replaced by a taper hole pin shaft 17 b.

The forward/reverse output mechanism 20 is fixed to the outer side of the long side of the L-shaped plate 23. The short sides of the L-shaped plate 23 are fixed to the base plate 2 by screws. The two output shafts of the positive and negative output mechanism 20 are both provided with transition sleeves 29, and the transition sleeves 29 can be fixed on flat keys of the output shafts through set screws. The two knurled screw sleeves 31 are respectively sleeved into two ends of the flexible shaft 30 outwards in a threaded manner. Two conical rolling heads 32 are respectively arranged at two ends of the flexible shaft 30. The end of the flexible shaft 30 is inserted into the hole of the conical rolling head 32, and after the end is inserted, the flexible shaft can be connected into a non-detachable integral structure by adopting a rolling method.

The cone part of the cone rolling head 32 at one end of the flexible shaft 30 is inserted into the cone hole of the transition sleeve 29 and is rotationally locked on the transition sleeve 29 through the knurled screw sleeve 31. The flexible shaft 30 is embedded in the groove of the guide wheel bracket 26. The guide wheel small shaft 25 is arranged on the round hole rear finger middle section 14a or the round hole front finger middle section 15a in an interference mode. The taper hole pin shaft 17b and the fingertip joint 18 are in interference fit or are bonded into a whole through strong glue. The conical part of the conical rolling head 32 at the other end of the flexible shaft 30 is inserted into the conical hole of the conical hole pin shaft 17 b. The angle of the finger tip section 18 is adjusted, and the finger tip section is rotationally locked on the taper hole pin shaft 17b by the knurled threaded sleeve 31. The two-way output mechanism 20 drives the flexible shaft 30 to rotate, so that the thin pin shaft 17a rotates, and the finger tip section 18 is driven to rotate.

EXAMPLE five

The embodiment discloses a single or double-knuckle contact flexible manipulator, and as shown in fig. 28 to 31, the motor single-worm double-worm-wheel positive and negative output shaft mechanism comprises a motor 20a, a half-flange upper cover 20b, a half-flange base 20c, a coupler 20d, a worm shaft end cover 20e, a small bearing 20f, a worm wheel shaft 20g, a right-handed worm wheel 20h, a two-way worm shaft 20i, a left-handed worm wheel 20j, a small key 20k, a worm shaft sealing cover 20l, a sleeve 20m, a large bearing 20n, a worm wheel sealing cover 20o, a worm wheel end cover 20p, a worm wheel and a worm.

The worm wheel is arranged at the lower part and the worm is arranged at the upper part. The half-flange upper cover 20b is disposed above the center line of the bidirectional worm shaft 20 i. The flange base 20c is disposed below the center line of the two-way worm shaft 20 i. The right-handed worm wheel 20h and the left-handed worm wheel 20j are respectively sleeved in the two worm wheel shafts 20g, and torque is transmitted through the two small keys 20k respectively. The two sides of the worm wheel shaft 20g are provided with large bearings 20n, and the large bearings 20n are arranged on the half-flange upper cover 20b and the half-flange lower base 20 c. The right-hand worm wheel 20h and the left-hand worm wheel 20j are provided with sleeves 20 m. The right-hand worm gear 20h and the left-hand worm gear 20j are coaxially assembled in a large hole of the flange base 20 c. After the position is adjusted, the worm gear cover 20o and the worm gear end cover 20p are fixed. The motor 20a is provided on a flange formed by the half-flange base 20c, and is coupled to the two-way worm shaft 20i through a coupling 20 d. Both ends of the bidirectional worm shaft 20i are provided with small bearings 20f, respectively. The worm shaft cover 20e and the worm shaft cover 20l are fixed to the flange base 20c outside the two small bearings 20f, and the half-flange upper cover 20b is fixed to the flange base 20c by bolts and nuts. The motor 20a, the worm shaft cover 20e, and the worm shaft cover 20l are screw-coupled to the half-flange upper cover 20 b.

EXAMPLE six

The embodiment discloses a gripping method of a single or double knuckle contact flexible manipulator, which is shown in fig. 32 to 35 and comprises the following steps:

a finger portion comprising three knuckles is used. The three knuckles are respectively a fingertip knuckle 18, a middle knuckle (in the first embodiment, the middle knuckle formed by the middle knuckle 14 behind the taper hole and the middle knuckle 15 in the front of the taper hole; or in the third embodiment and the fourth embodiment, the middle knuckle formed by the middle knuckle 14a behind the round hole and the middle knuckle 15a in the front of the round hole) and a base knuckle (i.e., the curved-bar base knuckle 10). The finger tip joint (namely the joint between the finger tip joint and the finger way joint), the middle finger joint (namely the joint between the middle finger joint and the finger root joint), and the finger root joint (namely the joint between the finger root joint and the moving push plate 3) of the finger part all rotate with a single degree of freedom and are on the same plane. The finger joints are pre-adjusted, the joints in the fingers are flexible joints without driving, and the finger root joints are automatically driven so as to clamp objects to be grabbed with different sizes; the angle between the fingertip joint 18 and the middle finger joint of each finger part is manually or automatically driven and adjusted in advance, then the base finger joint is automatically driven to rotate and clamp, when the contact surface of the object to be grabbed is a plane, the fingertip joint 18 and/or the middle finger joint are in parallel contact with the plane in contact with the object to be grabbed in the final grabbing pose, and the grabbing mode is adopted; when the contact surface of the object to be grabbed is a curved surface, in the final grabbing pose, the finger tip section 18 or the finger middle section is in tangential contact with the curved surface in contact with the object to be grabbed in a pinching mode, or the finger tip section 18 and the finger middle section are in tangential contact with the curved surface in contact with the object to be grabbed simultaneously in an enveloping grabbing mode.

When the object to be grabbed is a plane, the object can be a cuboid, a polygonal prism, a cylinder grabbed by finger tip sections in parallel to the central line, and the like. When the object to be grabbed is a curved surface, the object can be a sphere, a cylinder grabbed by finger tip sections perpendicular to the central line, and the like.

The larger the radius of curvature of the object to be grasped, the larger the angle between the finger tip segment 18 and the finger center segment can be adjusted. And the bent rod knuckle 10 is rotated to grasp the object to be grasped by the motor drive of angular displacement control or the cylinder drive of high-speed switch valve stroke control. The larger the size of the object, the more the torsion spring 12 on the flexible joint deforms and the stronger the contact force.

In addition, when one driving source 1 drives the finger root joint and the other driving source 1 drives the finger tip joint, the two motors can be cooperatively controlled through an algorithm to pinch or double-finger-joint enveloping and grabbing according to mechanistic, kinematic and contact state mechanical analysis.

Based on the above gripping method, the flexible manipulator of the embodiment may be composed of two sets of flexible finger parts which are bilaterally symmetrical. The finger part is formed by connecting finger tip joints, finger middle joints and finger root joints in series. Three single-degree-of-freedom joints of rotation, namely, a fingertip, a middle finger and a finger root, are formed on a finger plane. The joints in the fingers can be flexible joints of pre-tightened torsion springs 12; the finger tip joint 18 is manually adjusted, or a motor drives a self-locking motor single-worm double-worm gear positive and negative output shaft mechanism, and the angle of two finger tip joints is adjusted by means of the transmission of a rope or a flexible shaft, so that the contact state is adjusted; the drive mechanism driven by the knuckle can be a motor or a cylinder for generating the gripping action.

In addition, the feedback control method for the root segment driven by different modes and the fingertip segment 18 driven by different modes with or without driving is shown in table 1.

TABLE 1 drive and feedback control method

Referring to fig. 32 and 33, during grabbing operation, firstly, the relative height between the manipulator and the object to be grabbed is determined, the angle between the finger tip section 18 and the finger middle section is adjusted in advance, the push plate 3 is moved upwards, the two-force rod 8 is driven to enable the curved-rod finger root section 10 to rotate, the finger tip section 18 contacts the object to be grabbed, then the torque of the torsion spring 12 on the finger middle joint (flexible joint) is overcome, and the driving is stopped according to the displacement feedback of the driving source 1 until the final grabbing pose is reached. Which is a passive gripping mode by the torque action of the torsion spring 12.

Referring to fig. 34 and 35, in the grasping operation, the relative height between the manipulator and the object to be grasped is first determined, and the angle between the fingertip joint 18 and the middle finger joint is adjusted in advance by the size and shape of the object to be grasped. The universality and the adaptability are improved.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims

1. The utility model provides a single or two knuckle contact flexible manipulator which characterized in that: comprises a palm part and at least two groups of finger parts; the palm part comprises a driving source, a bottom plate and a movable push plate, the driving source is arranged on the bottom plate, and the movable push plate is arranged at the free end of the driving source; the finger part comprises a two-force rod, a bent rod knuckle, a middle knuckle and a fingertip knuckle which are sequentially hinged, the middle part of the bent rod knuckle is hinged on the bottom plate, the other end of the two-force rod is hinged on the movable push plate, and a torsion piece for enabling the middle knuckle and/or the fingertip knuckle to be bent inwards is arranged at least one position between the bent rod knuckle and the middle knuckle and between the middle knuckle and the fingertip knuckle.

2. The single or dual knuckle contact flexible manipulator of claim 1, wherein: the torsion member is a torsion spring.

3. The single or dual knuckle contact flexible manipulator of claim 2, wherein: holes are formed in the middle finger joint and the bent rod finger root joint, a thick pin shaft is arranged in each hole, a cotter pin penetrates through each thick pin shaft, the torsion spring is sleeved on the thick pin shaft, and two spring wires of the torsion spring respectively abut against and push the middle finger joint and the bent rod finger root joint.

4. The single or dual knuckle contact flexible manipulator of claim 3, wherein: an oblique narrow groove is formed in the root section of the bent rod finger, and one spring wire of the torsion spring is located in the oblique narrow groove.

5. The single or dual knuckle contact flexible manipulator of claim 1, wherein: the finger tip joint is provided with a hole, a threaded head pin shaft is tightly and fixedly arranged in the hole, the finger middle joint is provided with a taper hole, an outer taper sleeve is arranged in the taper hole, threads are arranged at two ends of the threaded head pin shaft, and a nut is sleeved on the threads.

6. The single or dual knuckle contact flexible manipulator of claim 1, wherein: the driving source is an air cylinder with displacement feedback or a screw shaft motor with feedback.

7. The single or dual knuckle contact flexible manipulator of claim 1, wherein: the bottom plate is provided with a positive and negative output mechanism, two output shafts of the positive and negative output mechanism are respectively provided with an inclined groove rope wheel, a series connection fine torsion spring is arranged at the hinged position of the finger tip section and the finger middle section, and a rope is arranged between the finger tip section and the inclined groove rope wheel.

8. The single or dual knuckle contact flexible manipulator of claim 1, wherein: the base plate is provided with a positive and negative output mechanism, two output shafts of the positive and negative output mechanism are respectively provided with a transition sleeve, the finger tip section and the finger middle section are hinged through a taper hole pin shaft, and a flexible shaft is arranged between the transition sleeve and the taper hole pin shaft.

9. The single or dual knuckle contact flexible manipulator of claim 7 or 8, wherein: the positive and negative output mechanism is a motor single-worm double-worm gear positive and negative output shaft mechanism.

10. A single or double knuckle contact flexible manipulator grasping method is characterized in that: the method comprises the following steps of using a finger part comprising three knuckles, wherein the three knuckles are a fingertip knuckle, a middle finger knuckle and a root finger knuckle respectively, the fingertip joints, the middle finger knuckle and the root finger knuckle of the finger part all rotate with a single degree of freedom and are on the same plane, the fingertip joints are pre-adjusted, the middle finger knuckle is a non-driven flexible joint, and the root finger knuckle is automatically driven to clamp objects to be grabbed with different sizes; the angle between the fingertip joint and the middle finger joint of each finger part is manually or automatically driven and adjusted in advance, then the base finger joint is automatically driven to rotate and clamp, when the contact surface of an object to be grabbed is a plane, the fingertip joint and/or the middle finger joint are in parallel contact with the plane of the object to be grabbed in the final grabbing pose, and the grabbing mode is adopted; when the contact surface of the object to be grabbed is a curved surface, in the final grabbing pose, the finger tip section or the finger middle section is in tangential contact with the curved surface in contact with the object to be grabbed in a pinching mode, or the finger tip section and the finger middle section are in tangential contact with the curved surface in contact with the object to be grabbed simultaneously in an enveloping grabbing mode.