CN111015700A

CN111015700A - Perception triggering zero-delay transmission parallel-clamping self-adaptive robot finger device

Info

Publication number: CN111015700A
Application number: CN201911267459.7A
Authority: CN
Inventors: 张文增; 赵元豪; 李明威; 李豪; 姚鹏; 郭伟波; 王旭超
Original assignee: Tianjin Research Institute For Advanced Equipment Tsinghua University Luoyang Advanced Manufacturing Industry Research And Development Base
Current assignee: Tianjin Research Institute For Advanced Equipment Tsinghua University Luoyang Advanced Manufacturing Industry Research And Development Base
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2020-04-17

Abstract

Perception triggers zero time delay transmission parallel clamp self-adaptation robot finger device belongs to robot hand technical field, including base, two finger sections, two joint shafts, motor, four-bar linkage, electro-magnet, double plate tooth mechanism, spring spare and stopper etc.. The device realizes the functions of parallel clamping and self-adaptive grabbing of the fingers of the double-joint robot, and can translate the second finger section to pinch an object or externally stretch the object according to the shape and the position of a target object, and can also sequentially rotate the first finger section and the second finger section to envelop the objects with different shapes and sizes; the device has zero time delay in the transmission process from flat clamping to self-adaptive grabbing, can quickly grab objects, and improves the working efficiency; the device has a large grabbing range; the device has compact structure, small volume and low manufacturing and maintenance cost, and is suitable for robot hands.

Description

Perception triggering zero-delay transmission parallel-clamping self-adaptive robot finger device

Technical Field

The invention belongs to the technical field of robot hands, and particularly relates to a structural design of a sensing triggering zero-delay transmission parallel clamp self-adaptive robot finger device.

Background

The robot finger is an important component of the robot, plays an important role in industrial production and other fields, and is very important for structural design and improvement of the robot finger device at the present stage. The parallel-clamping self-adaptive robot finger device can realize pinching and holding of objects and grabbing of the objects. The robot finger needs to accurately, quickly and stably grab objects and efficiently complete grabbing tasks. The self-adaptive under-actuated finger can be held in a self-adaptive object enveloping mode, but part of the self-adaptive under-actuated finger cannot be used for quickly grabbing, so that the working efficiency is greatly reduced.

The prior four-connecting-rod parallel-clamping self-adaptive robot finger device (Chinese patent with publication number of CN 105881565B) comprises a base, a middle finger section, a tail end finger section, a connecting rod, a convex block driving plate, a shifting wheel, a transmission gear mechanism and the like. The device has realized the parallel centre gripping of double joint robot finger and the function that self-adaptation snatched, and the device's is not enough to lie in: when the middle finger end touches an object, the lug driving plate cannot immediately touch the transmission lug, but has a lost motion stage, so that the tail end finger section cannot immediately rotate when the middle finger end touches the object, but has a certain time delay, thereby reducing the working efficiency of the robot finger;

an existing tendon rope type lateral locking linkage self-adaptive robot finger device (Chinese patent with publication number of CN 105619426B) comprises a base, a motor, a speed reducer, tendon ropes, N finger sections, N-1 joint spring pieces, a first rope pulling piece, N-1 joint sliding blocks, N-1 friction blocks, N-1 locking tendon ropes, N-1 locking spring pieces, a second rope pulling piece and the like. The device has realized the function that a plurality of joints are snatched with continuous synchronization locking to the self-adaptation, prevents that the finger from kick-backing unstability, can provide great grabbing power. The device has the following disadvantages: the device is intended to realize the quick grabbing of a heavy object, when the spring piece enables the fingers to be bent and enveloped by the elasticity of the spring piece to grab the object, a certain time delay exists when the motor pulls the key rope locking joint, and the device realize the quick grabbing of the heavy object are mutually contradictory.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a sensing triggering zero-delay transmission parallel-clamping self-adaptive robot finger device. The device has multiple grabbing modes, and can translate the second finger section to clamp an object and rotate the first finger section and the second finger section in sequence to envelope objects with different shapes and sizes in a self-adaptive manner; when the middle finger end touches an object, the tail end finger end starts to rotate immediately, and zero delay rotation is realized.

The purpose of the invention is realized by adopting the following technical scheme. The perception triggering zero-delay transmission parallel clamping self-adaptive robot finger device comprises a base, a first finger section, a second finger section, a near joint shaft, a far joint shaft, a motor and a transmission mechanism, wherein the base is provided with a first finger section and a second finger section; the motor is fixedly connected with the base; the transmission mechanism is arranged in the base; the output shaft of the motor is connected with the input end of the transmission mechanism; the proximal joint shaft is movably sleeved in the base; the far joint shaft is movably sleeved in the first finger section; the first finger section is sleeved on the proximal joint shaft; the second finger section is sleeved on the far joint shaft; the centerline of the proximal joint axis is parallel to the centerline of the distal joint axis; the device also comprises a first connecting rod, a second connecting rod, a third connecting rod, a first rotating shaft, a second rotating shaft, a driving disc tooth, a driven disc tooth, a key block, a first spring piece, a second spring piece, a third spring piece, a fourth spring piece, a limiting block, a contact inductor, a rotating plate, an electromagnet, a control module and a driving module; the output end of the transmission mechanism is connected with a driving disc tooth, and the driving disc tooth is movably sleeved on the near joint shaft; the driven disc teeth are sleeved on the near joint shaft in a sliding manner along the axial direction of the near joint shaft, sliding grooves are formed in the driven disc teeth, the key blocks are fixedly connected to the near joint shaft, and the key blocks are embedded in the sliding grooves of the driven disc teeth in a sliding manner; one end of the first connecting rod is fixedly sleeved on the near joint shaft, the other end of the first connecting rod is sleeved on the first rotating shaft, one end of the second connecting rod is sleeved on the first rotating shaft, the other end of the second connecting rod is sleeved on the second rotating shaft, one end of the third connecting rod is sleeved on the second rotating shaft, the other end of the third connecting rod is sleeved on the far joint shaft, and the second finger section is fixedly connected with the third connecting rod; the central points of the near joint shaft, the far joint shaft, the second rotating shaft and the first rotating shaft are respectively A, B, C, D, and then the line segment AB, the line segment BC, the line segment CD and the line segment AD form a parallelogram; two ends of the first spring piece are respectively connected with the driving disc tooth and the first finger section, two ends of the second spring piece are respectively connected with the base and the first connecting rod, and two ends of the third spring piece are respectively connected with the non-induction part of the contact inductor and the rotating plate; the rotating plate is embedded on the first finger section in a sliding mode and located outside the first finger section, and meanwhile the rotating plate is provided with a force application part which is in contact with a sensing part of the contact sensor but is not extruded when in an initial state; two ends of the fourth spring are respectively connected with the driving disc teeth and the driven disc teeth; the driving disc teeth are provided with fixed concave-convex gear teeth on one side close to the driven disc teeth, the driven disc teeth are provided with fixed concave-convex gear teeth on one side close to the driving disc teeth, and the driving disc teeth are not in contact with the driven disc teeth in an initial state; the electromagnet is fixedly connected to the near joint shaft, an output part of the electromagnet is connected with the driven disc teeth, and the motion direction of the output part of the electromagnet is parallel to the central line of the near joint shaft; the limiting block is fixedly connected with the base, and the first connecting rod is in contact with the limiting block in an initial state; the contact inductor is connected with the control module, the control module is connected with the driving module, the driving module is connected with the electromagnet, and the control module, the driving module and the contact inductor are all arranged in the first finger section.

Furthermore, the first spring piece adopts a tension spring, a pressure spring or a torsion spring; the second spring piece adopts a tension spring, a pressure spring or a torsion spring; the third spring piece adopts a tension spring or a compression spring; the fourth spring piece adopts a tension spring or a compression spring.

Further, the contact sensor is a switch, a pressure sensor or a proximity sensor.

Compared with the prior art, the invention has the following advantages and prominent effects:

the device comprehensively realizes the functions of parallel clamping and self-adaptive grabbing of the fingers of the double-joint robot by utilizing the motor, the four-bar mechanism, the double-disc tooth mechanism, the electromagnet, the spring piece, the limiting block and the like, and not only can translate the second finger section to clamp an object or externally stretch and take the object according to the shape and the position of a target object, but also can sequentially rotate the first finger section and the second finger section to envelop the objects with different shapes and sizes; the transmission process has no time delay from the flat clamp grabbing to the self-adaptive grabbing, and the object can be quickly grabbed; the grabbing range is large, an under-actuated mode is adopted, two joints are driven by one driver, and a complex sensing and control system is not needed; compact structure, small volume, low manufacturing and maintenance cost and suitability for robot hands.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a perspective external view of an embodiment of a sensing triggering zero-delay transmission parallel-clamping adaptive robot finger device designed by the invention.

Fig. 2 is a front external view of the embodiment shown in fig. 1.

Fig. 3 is a side elevational view of the embodiment of fig. 1 (right side elevational view of fig. 2).

Fig. 4 is a cross-sectional view of the embodiment shown in fig. 2 (right side view of fig. 2).

Fig. 5 is a schematic diagram of a disc tooth drive.

Fig. 6 is an exploded perspective view of fig. 5 (not shown in part).

Fig. 7 to 10 are schematic diagrams illustrating a parallel opening and closing adaptive object grabbing process, which is one way of grabbing objects according to the embodiment shown in fig. 1.

Fig. 11 to 13 are schematic views showing another way of gripping an object according to the embodiment shown in fig. 1, namely, an action process of gripping the object with a second finger section for parallel opening (called flat gripping).

[ reference numerals ]

1-base 10-limiting block 11-motor 111-speed reducer

112-first bevel gear 113-second bevel gear 114-transition gear shaft 115-first pulley

116-the conveyor belt 117-the second pulley 2-the first finger segment 21-the first link

211-first rotating shaft 22-second connecting rod 221-second rotating shaft 23-third connecting rod

3-second finger segment 4-proximal joint shaft 41-key block 5-distal joint shaft

6-driving disk tooth 61-first spring element 62-second spring element 63-third spring element

64-fourth spring 7-rotating plate 71-control module 72-drive module

73-contact inductor 8-driven disk teeth 81-electromagnet 82-object

Detailed Description

The details of the structure and the operation principle of the present invention are further described in detail below with reference to the accompanying drawings and embodiments.

Referring to fig. 1 to 6, an embodiment of a sensing triggering zero-delay transmission parallel-clamping adaptive robot finger device designed by the present invention is shown. The device comprises a base 1, a first finger section 2, a second finger section 3, a proximal joint shaft 4, a distal joint shaft 5, a motor 11 and a transmission mechanism; the motor 11 is fixedly connected with the base 1; the transmission mechanism is arranged in the base 1; the output shaft of the motor 11 is connected with the input end of the transmission mechanism; the proximal joint shaft 4 is movably sleeved in the base 1; the far joint shaft 5 is movably sleeved in the first finger section 2; the first finger section 2 is sleeved on the proximal joint shaft 4; the second finger section 3 is sleeved on the far joint shaft 5; the centerline of the proximal joint axis 4 is parallel to the centerline of the distal joint axis 5. The present embodiment further includes a first connecting rod 21, a second connecting rod 22, a third connecting rod 23, a first rotating shaft 211, a second rotating shaft 221, a driving disc tooth 6, a driven disc tooth 8, a key block 41, a first spring element 61, a second spring element 62, a third spring element 63, a fourth spring element 64, a limiting block 10, a contact sensor, a rotating plate 7, an electromagnet 81, a control module 71 and a driving module 72; the output end of the transmission mechanism is connected with the driving disc teeth 6; the driving disc teeth 6 are movably sleeved on the near joint shaft 4; the driven plate tooth 8 is sleeved on the near joint shaft 4 in a sliding manner along the axial direction of the near joint shaft 4, the driven plate tooth 8 is provided with a sliding groove, the key block 41 is fixedly connected to the near joint shaft 4, the key block 41 is embedded in the sliding groove of the driven plate tooth 8 in a sliding manner, and by means of the matching of the key block and the sliding groove, the driven plate tooth is enabled to slide along the axial direction of the near joint shaft on one hand, and the driven plate tooth is enabled to drive the near joint shaft to rotate on the other hand; one end of the first connecting rod 21 is fixedly sleeved on the proximal joint shaft 4, and the other end of the first connecting rod 21 is sleeved on the first rotating shaft 211; one end of the second connecting rod 22 is sleeved on the first rotating shaft 211, the other end of the second connecting rod 22 is sleeved on the second rotating shaft 221, and the center line of the first rotating shaft is parallel to the center line of the second rotating shaft; one end of the third connecting rod 23 is sleeved on the second rotating shaft 221, and the other end of the third connecting rod 23 is sleeved on the far joint shaft 5; the third connecting rod 23 is fixedly connected with the second finger section 33; referring to fig. 4, the central points of the proximal joint axis 4, the distal joint axis 5, the second rotation axis 221, and the first rotation axis 211 are respectively A, B, C, D, such that the length of the line segment AB is equal to that of the line segment CD, and the length of the line segment AD is equal to that of the line segment BC, i.e., the line segment AB, the line segment BC, the line segment CD, and the line segment AD form a parallelogram; two ends of the first spring piece 61 are respectively connected with the driving disc tooth 6 and the first finger section 2, two ends of the second spring piece 62 are respectively connected with the base 1 and the first connecting rod 21, and two ends of the third spring piece 63 are respectively connected with the non-induction part of the contact inductor 73 and the rotating plate 7; the rotating plate 7 is slidably embedded on the first finger section 2 and is positioned outside the first finger section 2, meanwhile, the rotating plate 7 is provided with a force application part which is in contact with the sensing part of the contact sensor 73 but is not extruded in the initial state, and in the self-adaptive grabbing mode, the rotating plate firstly touches an object 82 and then is stressed to move into the first finger section 2, so that the force application part is driven to instantaneously trigger the contact sensor 73; two ends of the fourth spring piece 64 are respectively connected with the driving disc teeth 6 and the driven disc teeth 8; the driving disc tooth 6 is provided with a fixed concave-convex gear tooth at one side close to the driven disc tooth 8, and the driven disc tooth 8 is provided with a fixed concave-convex gear tooth at one side close to the driving disc tooth 6; in the initial state, the driving disk teeth 6 are not in contact with the driven disk teeth 8 and are only separated by a small distance; the electromagnet 81 is fixedly connected to the near joint shaft 4, an output part of the electromagnet 81 is connected with the driven disc tooth 8, and the motion direction of the output part of the electromagnet 81 is parallel to the central line of the near joint shaft 4; the limiting block 10 is fixedly connected with the base 1, and the first connecting rod 21 is in contact with the limiting block 10 in an initial state; the contact sensor 73 is connected with the control module 71, the control module 71 is connected with the driving module 72, the driving module 72 is connected with the electromagnet 81, when the rotating plate 7 is stressed to move towards the inside of the first finger section 2, the contact sensor 73 receives a signal, the control module 71 enables the electromagnet 81 to work through the driving module 72, and the control module 71, the driving module 72 and the contact sensor 73 are all arranged in the first finger section 2.

In the present embodiment, the transmission mechanism includes a speed reducer 111, a first bevel gear 112, a second bevel gear 113, a transition gear shaft 114, a first pulley 115, a transmission belt 116, and a second pulley 117; an output shaft of the motor 11 is connected with an input shaft of a speed reducer 111, the first bevel gear 112 is fixedly sleeved on the output shaft of the speed reducer 111, the second bevel gear 113 is fixedly sleeved on a transition gear shaft 114, and the first bevel gear 112 is meshed with the second bevel gear 113; the transition gear shaft 114 is sleeved in the base 1, the first belt wheel 115 is fixedly sleeved on the transition gear shaft 144, the second belt wheel 117 is movably sleeved on the proximal joint shaft 4, the second belt wheel 117 is fixedly connected with the driving disc teeth 6, the transmission belt 116 is connected with the first belt wheel 115 and the second belt wheel 117, the transmission belt 116, the first belt wheel 115 and the second belt wheel 117 form a belt wheel transmission relationship, and the transmission belt is in an O shape. On the basis of the transmission mechanism, because the second belt wheel is fixedly connected with the driving disc tooth, the first spring piece is sleeved on the outer side of the near-joint shaft in order to facilitate assembly, and two ends of the first spring piece are respectively connected with the second belt wheel and the first finger section so as to drive the first finger section to rotate when the second belt wheel and the driving disc tooth rotate.

In this embodiment, the first spring element 61 is a torsion spring, but may be a compression spring or a torsion spring in other embodiments; the second spring element 62 is a tension spring, but may be a compression spring or a torsion spring in other embodiments; the third spring element 63 is a pressure spring, but may be a tension spring in other embodiments; the fourth spring element is a pressure spring, but may be a tension spring in other embodiments.

In the present embodiment, the urging portion for triggering the contact sensor 73 when the rotating lever 7 moves is fitted inside the third spring member 63, but the third spring member and the urging portion may be separately disposed in other embodiments.

In this embodiment, the contact sensor 73 is a pressure sensor, but may be a switch or a proximity sensor in other embodiments.

The working principle of this embodiment is described below with reference to fig. 7 to 13:

in this embodiment, the initial position is set to a state in which the finger is straightened.

When the object 82 is grabbed, the motor 11 rotates, the driving disc tooth 6 is driven by the transmission of the transmission mechanism, the first spring 61 drives the first finger section 2 to rotate around the center line of the proximal joint shaft 4, and the line segment ABCD forms a parallelogram, so that the second finger section 3 and the fixedly connected third connecting rod 23 can keep an initial state under the action of the parallel four-bar linkage, the first connecting rod 21 is connected with the base 1 through the second spring 62, and the first connecting rod 21 does not rotate along with the first finger section 2, so that the second finger section 3 only performs translational motion relative to the base 1 without rotating, and keeps an original posture, the second finger section 3 is always in the same posture relative to the base 1, which is a stage of parallel clamping, and the action process is shown in fig. 11 to 13. This stage is suitable for holding the object 82 with the second finger section 3 or for holding the object 82 by means of a second finger section 3 by means of a flaring in such a way that it opens from the inside to the outside. Such as a hollow cylindrical barrel, that opens outwardly from the inside of the object 82 to hold the barrel wall for access to the object 82.

When the first finger section 2 contacts the object 82 and is blocked by the object 82 and can not rotate any more, the second stage of the adaptive envelope is entered, at this time, the rotating plate 7 contacts the object 82 first and moves towards the first finger section 2, so that the third spring 63 deforms, and then the contact sensor 73 is triggered, when the contact sensor 73 receives a signal, the electromagnet 81 is enabled to operate through the control module 71 and the driving module 72, so that the output member of the electromagnet 81 on the first connecting rod pushes the driven disk tooth 8 to slide on the key block of the proximal joint shaft along the axial direction, the driven disk tooth 8 is meshed with the driving disk tooth 6, so that the proximal joint shaft 4, the first connecting rod 21, the key block, the driven disk tooth 8 and the driving disk tooth 6 are synchronously driven, the first connecting rod 21 leaves the limiting block 10, so that the second spring 62 deforms, and because the third connecting rod 23 is parallel to the first connecting rod 21, the third connecting rod 23 and the second finger section 3 rotate around the central line of the distal joint shaft 5, until the second finger section 3 contacts the object 82, the effect of adaptive envelope grabbing the object 82 is completed, and the action process is as shown in fig. 7 to 10. The present embodiment is adaptive to objects 82 of different shapes and sizes, and can grasp a variety of objects 82.

Process of releasing the object: the motor rotates reversely, and the subsequent process is just opposite to the process of grabbing the object, so that the description is omitted.

Finally, the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and other modifications or equivalent substitutions made by the technical solutions of the present invention by those of ordinary skill in the art should be covered within the scope of the claims of the present invention as long as they do not depart from the design and scope of the technical solutions of the present invention.

Claims

1. The perception triggering zero-delay transmission parallel clamping self-adaptive robot finger device comprises a base, a first finger section, a second finger section, a near joint shaft, a far joint shaft, a motor and a transmission mechanism; the motor is fixedly connected with the base; the transmission mechanism is arranged in the base; the output shaft of the motor is connected with the input end of the transmission mechanism; the proximal joint shaft is movably sleeved in the base; the far joint shaft is movably sleeved in the first finger section; the first finger section is sleeved on the proximal joint shaft; the second finger section is sleeved on the far joint shaft; the centerline of the proximal joint axis is parallel to the centerline of the distal joint axis;

the method is characterized in that: the perception triggering zero-delay transmission parallel-clamping self-adaptive robot finger device further comprises a first connecting rod, a second connecting rod, a third connecting rod, a first rotating shaft, a second rotating shaft, a driving disc tooth, a driven disc tooth, a key block, a first spring piece, a second spring piece, a third spring piece, a fourth spring piece, a limiting block, a contact inductor, a rotating plate, an electromagnet, a control module and a driving module; the output end of the transmission mechanism is connected with a driving disc tooth, and the driving disc tooth is movably sleeved on the near joint shaft; the driven disc teeth are sleeved on the near joint shaft in a sliding manner along the axial direction of the near joint shaft, sliding grooves are formed in the driven disc teeth, the key blocks are fixedly connected to the near joint shaft, and the key blocks are embedded in the sliding grooves of the driven disc teeth in a sliding manner; one end of the first connecting rod is fixedly sleeved on the near joint shaft, the other end of the first connecting rod is sleeved on the first rotating shaft, one end of the second connecting rod is sleeved on the first rotating shaft, the other end of the second connecting rod is sleeved on the second rotating shaft, one end of the third connecting rod is sleeved on the second rotating shaft, the other end of the third connecting rod is sleeved on the far joint shaft, and the second finger section is fixedly connected with the third connecting rod; the central points of the near joint shaft, the far joint shaft, the second rotating shaft and the first rotating shaft are respectively A, B, C, D, and then the line segment AB, the line segment BC, the line segment CD and the line segment AD form a parallelogram; two ends of the first spring piece are respectively connected with the driving disc tooth and the first finger section, two ends of the second spring piece are respectively connected with the base and the first connecting rod, and two ends of the third spring piece are respectively connected with the non-induction part of the contact inductor and the rotating plate; the rotating plate is embedded on the first finger section in a sliding mode and located outside the first finger section, and meanwhile the rotating plate is provided with a force application part which is in contact with a sensing part of the contact sensor but is not extruded when in an initial state; two ends of the fourth spring are respectively connected with the driving disc teeth and the driven disc teeth; the driving disc teeth are provided with fixed concave-convex gear teeth on one side close to the driven disc teeth, the driven disc teeth are provided with fixed concave-convex gear teeth on one side close to the driving disc teeth, and the driving disc teeth are not in contact with the driven disc teeth in an initial state; the electromagnet is fixedly connected to the near joint shaft, an output part of the electromagnet is connected with the driven disc teeth, and the motion direction of the output part of the electromagnet is parallel to the central line of the near joint shaft; the limiting block is fixedly connected with the base, and the first connecting rod is in contact with the limiting block in an initial state; the contact inductor is connected with the control module, the control module is connected with the driving module, the driving module is connected with the electromagnet, and the control module, the driving module and the contact inductor are all arranged in the first finger section.

2. The perceptually-triggered zero-delay transmission parallel-clamping adaptive robot finger device according to claim 1, wherein: the first spring piece adopts a tension spring, a pressure spring or a torsion spring; the second spring piece adopts a tension spring, a pressure spring or a torsion spring; the third spring piece adopts a tension spring or a compression spring; the fourth spring piece adopts a tension spring or a compression spring.

3. The perceptually-triggered zero-delay transmission parallel-clamping adaptive robot finger device according to claim 1, wherein: the contact sensor adopts a switch, a pressure sensor or a proximity sensor.