CN111452065A

CN111452065A - Fluid-driven membrane shrinkage rod array self-adaptive robot hand device

Info

Publication number: CN111452065A
Application number: CN202010261190.8A
Authority: CN
Inventors: 徐汉波; 张文增; 徐向荣; 骆浩威; 周呈玥; 黄汉燕; 杨少丹; 鲁志敏
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: 2020-04-03
Filing date: 2020-04-03
Publication date: 2020-07-28

Abstract

Fluid drive membrane shrink pole array self-adaptation robot hand device belongs to robot hand technical field, including base, a plurality of slip push rod, a plurality of spring spare, a plurality of sleeve pipes, a plurality of tendon rope, a plurality of stopper, clamping ring, fluid drive source and membrane. The device is used for the robot to snatch the object, has realized the self-adaptation and has snatched the function. When contacting an object, the vertical movement of a plurality of sliding push rods and spring elements is utilized to obtain the self-adaptive effect on the size and the shape of the object; the fluid is pumped by the fluid driving source to make the membrane concave, so that the sliding push rods gather towards the center, the multi-directional gripping effect on the object is achieved, and the flexible and stable gripping on the object can be realized; the device has the advantages of simple structure, good reliability and wide application range.

Description

Fluid-driven membrane shrinkage rod array self-adaptive robot hand device

Technical Field

The invention belongs to the technical field of robot hands, and particularly relates to a structural design of a fluid-driven membrane shrinkage rod array self-adaptive robot hand device.

Background

Robot hands have a wide range of uses in the field of robotics for establishing temporary connections and fixed relationships between robots and objects, and for enabling release at the appropriate time, the former enabling gripping of objects and the latter enabling releasing of objects. A general robot hand is manufactured to have two relatively moving parts in order to reduce costs, so as to easily perform grasping and releasing functions. There are also many structures that mimic the human hand, designing more fingers and several joints on the fingers, but that brings with it the complexity and high cost of the mechanical systems, sensing systems, control systems and control algorithms. Some robot hands have the adaptability, do not know the shape and the size of the object of will grasping before grasping yet, do not carry out sensing detection to the object of grasping yet in grasping yet, but can grasp adaptively, this kind to the automatic adaptability of object shape, size make robot hand realize not increasing sensing and control demand when realizing that more extensively grasps different objects.

Peter b.scott describes in The literature (Peter b.scott, "The 'omnigrip': a form of robituversal grip", Robotica, vol.3: pp 153-. The holder has a structure that two groups of rod clusters are integrated, each group of rod clusters is provided with a plurality of long rods which are parallel to each other, the long rods which are pushed by an object to be grabbed and slide up and down freely achieve the purpose of adapting to the shape of the object, and then the two groups of rod clusters are driven to get close or leave by combining with a driver, so that the object can be grabbed. For example, when the end of the robot leans against an object placed on a support surface (such as a table top), the object extrudes the long rods to slide towards the base, and because the number of the long rods is large and the long rods are thin (the diameter is small), different long rods contact different object surface points, and the sliding distances of the long rods towards the palm are different due to the shapes of the objects; then, two groups of left and right rod clusters are gathered to clamp the object, and the object is clamped from the side surface by the long rods, so that the grabbing purpose is achieved.

The device has the following disadvantages:

(1) multi-directional grasping cannot be achieved. When the device applies a gripping force to a target object, the gripping force can only be along the direction of the gathering of the two groups of rod clusters, which is equivalent to a two-finger gripper, only a one-dimensional gripping mode is generated, and the gripping effect is poor.

(2) The grip fails for an elongated object placed in a particular direction. When the target object is parallel to the direction and the target object is longer than the device in the direction, the target object does not receive holding force due to the folding of the two groups of telescopic rods, such as a long strip-shaped object is held.

(3) The structure is complex and the energy consumption is large. The device has 2 groups of rod cluster assemblies, needs 2 movable supporting parts (or moving bases) which move mutually, a set of linear guide rails, 2 sliding blocks, a driver, a transmission mechanism and the like, has a more complex structure, and is more energy-consuming to move a heavy rod cluster assembly with a plurality of long rods.

(4) Grip stability is to be improved. The device only adopts the grabbing power that two sets of pole cluster sets closed and produce to snatch the target object, lacks better enveloping type and seals the effect of snatching. Force-closed grasping an object does not necessarily result in a form-closed grasping, but a form-closed grasping must include a force-closed grasping, and thus grasping stability is best for achieving a form-closure.

(5) The clamping force of each rod is not uniform when grabbing an object. The device clamps the object by adopting a mode of two groups of rod clusters in a translational folding mode, and when clamping the object, the rod which is firstly contacted with the object in each group of rod clusters is subjected to the largest lateral force, and the rod which is finally contacted with the object is subjected to the smallest force. The clamping force on the rod gripping the object will be uneven, especially when gripping more rigid objects. This may result in bending deformation of the rod that first contacts the object.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a fluid-driven membrane contraction rod array self-adaptive robot hand device. The device is used for grabbing objects and has self-adaptability to the size and the shape of the objects; the multidirectional grasping effect on the object is achieved: the device can provide a gripping force for the object in multiple directions, and can effectively grip various shapes (including long strips) of objects placed in different directions; the gripping force is uniform and the gripping effect is good due to the fluid driving and the membrane contraction; the structure is simple, the grasping is rapid, and the time consumption for grasping the object is short; the device is suitable for being used in a severe working environment, and has good reliability for long-term use, long service life and high grasping stability.

The purpose of the invention is realized by adopting the following technical scheme. The invention provides a fluid-driven membrane contraction rod array self-adaptive robot hand device which comprises a base, K sleeves, K spring pieces, K limiting blocks and K sliding push rods, wherein the K sleeves are arranged on the base; the ith sliding push rod is sleeved in the ith sleeve in a sliding manner, and the sliding direction of the ith sliding push rod in the corresponding sleeve is parallel to the central line of the sleeve; two ends of the ith spring piece are respectively connected with the ith sleeve and the ith sliding push rod, and the ith spring piece enables the ith sliding push rod to tend to leave the ith sleeve; the ith limiting block is fixedly connected with the ith sleeve, the ith sliding push rod is contacted with the ith limiting block under the elastic force of the ith spring piece at the initial position, and the ith limiting block limits the limit position of the ith sliding push rod, which slides along the direction away from the ith sleeve; when in the initial position, the central lines of all the sliding push rods are parallel to each other; the fluid-driven membrane contraction rod array self-adaptive robot hand device further comprises a membrane, M tendon ropes, a clamping ring, fluid and a fluid driving source; the base includes at least one port; the fluid driving source is communicated with the port; the clamping ring fixedly connects the membrane to the base; the membrane is deformable, K through holes are formed in the membrane, and the ith sleeve is fixedly sleeved in the ith through hole; one end of each sliding push rod extends out from the same side of the sleeve; one side of the membrane, the inner wall of the base and the outer surfaces of all the sleeves form a sealed chamber, and the fluid exists in the chamber; m tendon ropes are arranged in the chamber, and two ends of each tendon rope are respectively connected with the inner wall of the base and the surface of the membrane; in the initial position the chamber is filled with fluid; the length of the tendon rope is set to be the length which keeps the lower surface of the membrane skin to be flat when in the initial position; wherein K is a natural number greater than 2; 1,2 …, K; i is a natural number; m is a natural number greater than 0.

Further, the fluid driving source employs a reversible action pump.

Further, the fluid is a liquid.

Further, the liquid is water.

Furthermore, the membrane is made of flexible materials.

Compared with the prior art, the invention has the following outstanding characteristics:

the device of the invention adopts a plurality of sliding push rods, the deformable membrane and fluid to comprehensively realize the self-adaptive grabbing function of discrete space, and utilizes the plurality of sliding push rods to realize the self-adaptive function to the size and shape of the object without adjusting the device according to the shape and size of the object; the film is contracted when fluid is discharged, so that the sliding push rods are gathered to the center, the multi-directional flexible clamping effect on the object is achieved, the clamping force is uniform, and the clamping stability is high; the device can effectively grip various objects (including long strips) placed in different directions; the device only needs one set of rod cluster and fluid driver, so the structure is simple; only need draw out fluid in the cavity that membrane skin, base and sleeve pipe constitute, just can easily let the slip push rod to the center slope and gather together, thereby a plurality of push rods reach the purpose of centre gripping object, consequently the energy consumption is low, grab and hold fast, consuming time weak point. The device has simple structure, good use reliability and long service life; since multi-directional grasping is achieved, it is possible to provide grasping force to the target object in multiple directions, and therefore grasping stability is high.

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 view of one embodiment of a fluid driven membrane contraction rod array adaptive robotic hand device provided by the present invention.

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

Fig. 3 is a bottom view of the embodiment shown in fig. 1.

Fig. 4 is a cross-sectional view of the embodiment shown in fig. 1.

Fig. 5 and 6 are schematic views of a process for grabbing the spherical target object according to the embodiment shown in fig. 1.

Fig. 7 is a three-dimensional appearance of the embodiment of fig. 1 for grabbing a spherical target object.

Fig. 8 is a cross-sectional view of the embodiment of fig. 1 capturing a spherical target object.

Fig. 9 is a schematic view of a process for grasping an elongated target object according to the embodiment shown in fig. 1.

[ reference numerals ]

1-base, 100-port, 2-fluid, 3-sleeve, 4-spring,

5-a clamping ring, 6-a membrane, 7-a limiting block, 8-a sliding push rod, 9-a spherical object,

10-elongated object, 11-tendon rope.

Detailed Description

The following describes the specific structure, operation principle and operation process of the present invention in detail with reference to the accompanying drawings and embodiments.

The invention discloses a fluid-driven membrane contraction rod array self-adaptive robot hand device which comprises a base, K sleeves, K spring pieces, K limiting blocks and K sliding push rods, wherein the K sleeves are arranged on the base; the ith sliding push rod is sleeved in the ith sleeve in a sliding manner; the sliding direction of the ith sliding push rod in the corresponding sleeve is parallel to the central line of the sleeve; two ends of the ith spring piece are respectively connected with the ith sleeve and the ith sliding push rod; the ith spring causes the ith sliding push rod to tend to leave the ith sleeve; the ith limiting block is fixedly connected with the ith sleeve; at the initial position, the ith sliding push rod is contacted with the ith limit block under the elastic force of the ith spring piece; the ith limiting block limits the limit position of the ith sliding push rod to slide along the direction away from the ith sleeve; in the initial position, the centre lines of all the sliding push rods are parallel to each other. The fluid-driven membrane contraction rod array self-adaptive robot hand device further comprises a membrane, M tendon ropes, a clamping ring, fluid and a fluid driving source; the base includes at least one port; the fluid driving source is communicated with the port; the clamping ring fixedly connects the membrane to the base; k through holes are formed in the membrane; the ith sleeve is fixedly sleeved in the ith through hole; one end of each sliding push rod extends out from the same side of the sleeve; the membrane is deformable; one side of the membrane, the inner wall of the base and the outer surfaces of all the sleeves form a sealed chamber, and the fluid exists in the chamber; m tendon ropes are arranged in the chamber, and two ends of each tendon rope are respectively connected with the inner wall of the base and the surface of the membrane; the chamber being filled with fluid in an initial position; the length of the tendon rope is set to be the length which keeps the lower surface of the membrane skin to be flat when in the initial position; the membrane is made of flexible materials; wherein K is a natural number greater than 2; 1,2 …, K; i is a natural number; m is a natural number greater than 0.

When K is 34 and M is 9, the following are:

an embodiment of the fluid-driven membrane contraction rod array adaptive robot hand device designed by the invention is shown in fig. 1, fig. 2, fig. 3 and fig. 4, and defines that a port is located at an "upper" position and a sliding push rod is located at a "lower" position. The embodiment comprises a base 1, 34 sleeves 3, 34 spring elements 4, 34 limiting blocks 7 and 34 sliding push rods 8; the ith sliding push rod 8 is sleeved in the ith sleeve 3 in a sliding manner, and the sliding direction of the ith sliding push rod 8 in the corresponding sleeve is parallel to the central line of the sleeve 3; the ith spring element 4 is sleeved in the ith sleeve 3, two ends of the ith spring element are respectively connected with the ith sleeve 3 and the ith sliding push rod 8, and the ith spring element 4 enables the ith sliding push rod 8 to tend to leave the ith sleeve 3; an ith limit block 7 is fixedly connected with the lower end of the ith sleeve 3, an ith sliding push rod 8 is contacted with the ith limit block 7 under the elasticity of an ith spring piece at the initial position, the ith limit block 7 limits the ith sliding push rod 8 to slide to a lower limit position, and the ith sliding push rod is prevented from falling off from the corresponding ith sleeve; in the initial position, the centerlines of the 34 sliding push rods are parallel to each other and form a multi-layered circumferential array. The embodiment also comprises a

membrane

6, 9 tendon ropes 11, a clamping ring 5, fluid 2 and a fluid driving source; the base 1 includes a port 100 at an upper surface; the fluid drive source is in communication with port 100; the lower end of the base 1 is open, and the clamping ring 5 fixedly connects the membrane 6 to the lower end of the base 1 in a sealing manner; the membrane 6 is provided with 34 through holes distributed in a circumferential array; the ith sleeve 3 is fixedly sleeved in the ith through hole and is positioned in the base 1; the lower ends of the 34 sliding push rods 8 all extend out of the lower sides of the corresponding sleeves; the membrane 6 is deformable; the upper side of the membrane 6, the inner wall of the base 1 and the outer surfaces of the 34 sleeves constitute a sealed chamber in which the fluid is present; 9 tendon ropes 11 are arranged in the chamber, and two ends of each tendon rope 11 are respectively connected with the upper surface of the inner wall of the base 1 and the upper surface of the membrane 6; the chamber being filled with fluid in an initial position; the length of the tendon string 11 is set to a length that keeps the lower surface of the membrane in a plane in the initial position; the membrane is made of flexible materials; wherein, i is 1,2,3 …, 34; i is a natural number.

In this embodiment, the fluid driving source is a pump, specifically, a reversible pump.

In this embodiment, the fluid 2 is a liquid, specifically water.

In this embodiment, the limiting block 7 includes a cylindrical body and a blocking edge arranged at the lower end of the cylindrical body, and the blocking edge of the ith limiting block 7 and the lower end of the ith sleeve 3 form blocking fit during installation; the upper end of the ith sliding push rod 8 is provided with a step which is used for forming stop matching with the upper end of the cylindrical body so as to limit the ith sliding push rod to slide to the limit position below.

In this embodiment, the membrane 6 is made of any one of a vinyl and an elastic material.

The operation of the embodiment of fig. 1 will now be described with reference to the accompanying drawings.

The initial state of this embodiment is shown in fig. 1, fig. 2, fig. 3 and fig. 4, when under the elastic force of the ith spring element, most part of the ith sliding push rod extends out of the ith sleeve and is outside the chamber formed by the membrane, the base and the sleeve, wherein i is 1,2, …, 34.

When the embodiment is used for grabbing a target object, the inner wall of the base, the membrane and the sleeve form a sealed chamber, the chamber is filled with water, and the membrane is kept in a horizontal state under the action of the tendon rope. When an object is clamped, the device is driven by the mechanical arm to be close to the object placed on the supporting surface and extrude the object, part of the sliding push rod slides upwards for different distances relative to the device by extrusion force so as to adapt to the surface shape above the object, then the fluid driving source connected to the port of the base starts to work, fluid in the cavity is reduced, and at the moment, the center of the membrane is concave towards the cavity to form a concave surface with a high middle part and a low edge. At the moment, the film skin drives the sliding push rod through the sleeve, so that the sliding push rod inclines towards the middle, the sliding push rod is gathered in a conical shape, the object is self-adaptive from the side by means of the sliding push rod, the object is flexibly clamped from multiple directions, the action process of grabbing the spherical object is shown in figures 5, 6, 7 and 8, and the action process of grabbing the strip-shaped object is shown in figure 9.

When the object is released, the fluid driving source connected with the port starts to work, fluid is filled into a cavity formed by the base, the sleeve and the membrane, when the cavity is slowly filled with the fluid, the membrane is gradually changed from an inward concave state to a horizontal state, all the sliding push rods are also restored to an initial state in which the center lines of the sliding push rods are parallel to each other from an inclined conical state, the grabbing force on the target object is eliminated, and the target object is released.

The device adopts a plurality of sliding push rods, the deformable membrane and the fluid to realize the self-adaptive flexible grabbing function, realizes the self-adaptive function to the size and the shape of the object by utilizing the plurality of sliding push rods, does not need to adjust the device according to the shape and the size of the object, and utilizes the contraction of the membrane when the fluid is discharged to lead the plurality of sliding push rods to gather towards the center, thereby achieving the multi-directional flexible clamping effect to the object; the device can effectively hold various objects with different shapes (including long strips) placed in different directions; the device only needs one set of rod cluster and fluid driver, so the structure is simple; the sliding push rod can be easily gathered towards the center only by pumping fluid out of the cavity, so that the purpose of clamping an object is achieved, and the device is low in energy consumption, quick to grasp and short in time consumption; the device has simple structure, good reliability for long-term use and long service life; since multi-directional grasping is achieved, it is possible to provide grasping force to the target object in multiple directions, and therefore grasping stability is high.

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. A fluid-driven membrane shrinkage rod array self-adaptive robot hand device comprises a base, K sleeves, K spring pieces, K limiting blocks and K sliding push rods; the ith sliding push rod is sleeved in the ith sleeve in a sliding manner, and the sliding direction of the ith sliding push rod in the corresponding sleeve is parallel to the central line of the sleeve; two ends of the ith spring piece are respectively connected with the ith sleeve and the ith sliding push rod, and the ith spring piece enables the ith sliding push rod to tend to leave the ith sleeve; the ith limiting block is fixedly connected with the ith sleeve, the ith sliding push rod is contacted with the ith limiting block under the elastic force of the ith spring piece at the initial position, and the ith limiting block limits the limit position of the ith sliding push rod, which slides along the direction away from the ith sleeve; when in the initial position, the central lines of all the sliding push rods are parallel to each other; the method is characterized in that: the fluid-driven membrane contraction rod array self-adaptive robot hand device further comprises a membrane, M tendon ropes, a clamping ring, fluid and a fluid driving source; the base includes at least one port; the fluid driving source is communicated with the port; the clamping ring fixedly connects the membrane to the base; the membrane is deformable, K through holes are formed in the membrane, and the ith sleeve is fixedly sleeved in the ith through hole; one end of each sliding push rod extends out from the same side of the sleeve; one side of the membrane, the inner wall of the base and the outer surfaces of all the sleeves form a sealed chamber, and the fluid exists in the chamber; m tendon ropes are arranged in the chamber, and two ends of each tendon rope are respectively connected with the inner wall of the base and the surface of the membrane; in the initial position the chamber is filled with fluid; the length of the tendon rope is set to be the length which keeps the lower surface of the membrane skin to be flat when in the initial position; wherein K is a natural number greater than 2; 1,2 …, K; i is a natural number; m is a natural number greater than 0.

2. The fluid driven membrane shrinkage rod array adaptive robot hand device of claim 1, wherein: the fluid driving source employs a reversible action pump.

3. The fluid driven membrane shrinkage rod array adaptive robot hand device of claim 1, wherein: the fluid is a liquid.

4. The fluid driven membrane shrinkage rod array adaptive robot hand device of claim 3, wherein: the liquid is water.

5. The fluid driven membrane shrinkage rod array adaptive robot hand device of claim 1, wherein: the membrane is made of flexible materials.