Differential parallel link linear flat clamp double-finger segment adaptive robot finger device

Abstract

The differential parallel connecting rod linear flat clamping double-finger segment adaptive robot finger device belongs to the field of robot hand technology, including a base, a motor, a transmission mechanism, three finger segments, multiple connecting rods, multiple shafts, two springs and two limit blocks. The device adopts a motor, a transmission mechanism, three finger segments, multiple connecting rods, multiple shafts, two springs and two limit blocks to comprehensively realize the three-joint linear flat clamping and adaptive grasping mode. In the initial stage, the device is in a linear parallel clamping mode: the third finger segment moves horizontally and the trajectory is an approximate straight line, which is suitable for clamping objects on the plane; when the first finger segment contacts the object and is blocked, the device enters the adaptive grasping mode, multiple finger segments contact the object, and it is adaptive to objects of different shapes and sizes. Only one motor is used to drive three joints, which is simple to control, stable grasping, and low manufacturing and maintenance costs.

Description

Technical Field

[0001] The invention belongs to the technical field of robot hands, and in particular relates to a structural design of a differential parallel connecting rod straight-line flat clamp double-finger segment adaptive robot finger device. Background Art

[0002] The underactuated hand reduces the number of motors used, so that the robot hand can ensure anthropomorphic movements while reducing the requirements for real-time hand sensing and control systems. Existing underactuated fingers include flat gripping fingers, coupled fingers, and adaptive fingers. The end of the flat gripping finger maintains an unchanged posture relative to the base during the grasping process, which is suitable for grasping objects on the table; when the first finger segment of the coupled finger rotates, the third finger segment will rotate relative to the first finger segment at the same time, making the grasping action more anthropomorphic and the grasping faster; the adaptive finger rotates first near the joint, and the first finger segment contacts the object before triggering the next joint to rotate, and so on, until the end finger segment contacts the object, achieving an envelope grasping effect in which multiple finger segments all contact the object, adapting to objects of different shapes and sizes. The flat gripping adaptive finger is a composite grasping type finger that combines parallel gripping and adaptive grasping functions in two time stages. The coupled adaptive finger is another composite grasping finger that combines coupled grasping with adaptive grasping.

[0003] The traditional flat-clamp adaptive finger is a flat-clamp adaptive finger with an arc trajectory at the end, and cannot achieve a flat-clamp adaptive compound grasping mode with a straight trajectory at the end. When grasping objects on the desktop, the robotic arm needs to cooperate with the control to achieve more accurate object grasping, which brings trouble to the control of the robotic arm. At the same time, when grasping objects of different sizes, the device needs to operate at different heights, otherwise there is a risk of the end finger of the device colliding with the desktop. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a differential parallel connecting rod linear flat clamping double-finger segment adaptive robot finger device. The device has three joints, can realize the parallel clamping function of the end finger segment in an approximately linear trajectory, and can adaptively envelope and grasp objects of different shapes and sizes.

[0005] The technical solution of the present invention is as follows:

[0006] The differential parallel-link linear flat-clamp double-finger-segment adaptive robot finger device designed by the present invention comprises a base, a first finger segment, a second finger segment, a third finger segment, a proximal joint axis, a middle joint axis, a distal joint axis, a motor and a transmission mechanism; the motor is fixedly connected to the base, and the motor is connected to the input end of the transmission mechanism; the proximal joint axis is sleeved in the base, the first finger segment is sleeved on the proximal joint axis, the middle joint axis is sleeved in the first finger segment, the second finger segment is sleeved on the middle joint axis, the distal joint axis is sleeved in the second finger segment, and the third finger segment is sleeved on the distal joint axis; the center lines of the proximal joint axis, the middle joint axis and the distal joint axis are parallel to each other; it is characterized in that: the differential parallel-link linear flat-clamp double-finger-segment adaptive robot finger The device also includes a first connecting rod, a second connecting rod, a third connecting rod, a fourth connecting rod, a fifth connecting rod, a sixth connecting rod, a first shaft, a second shaft, a third shaft, a fourth shaft, a fifth shaft, a sixth shaft, a seventh shaft, a first spring, a second spring, a first limit block and a second limit block; the center lines of the first shaft, the second shaft, the third shaft, the fourth shaft, the fifth shaft, the sixth shaft, the seventh shaft and the proximal joint shaft are parallel to each other; the first shaft is sleeved in the base, and the first connecting rod is sleeved on the first shaft; the output end of the transmission mechanism is connected to the first connecting rod; the second shaft is sleeved in the first connecting rod, and the second connecting rod is sleeved on the second shaft; the third shaft is sleeved in the second connecting rod; the third connecting rod is sleeved on the third shaft, and the third connecting rod is sleeved on the middle joint shaft ; The fourth shaft sleeve is arranged in the third connecting rod; the fourth connecting rod is sleeved on the fourth shaft; the fifth shaft sleeve is arranged in the fourth connecting rod, and the third finger segment is sleeved on the fifth shaft; the sixth shaft sleeve is arranged in the base, and the fifth connecting rod is sleeved on the sixth shaft; the seventh shaft sleeve is arranged in the fifth connecting rod, the sixth connecting rod is sleeved on the seventh shaft, and the sixth connecting rod is sleeved on the middle joint shaft; the two ends of the first spring member are respectively connected to the first connecting rod and the second connecting rod; the two ends of the second spring member are respectively connected to the sixth connecting rod and the second finger segment; the first limit block is fixedly connected to the first connecting rod, and the second limit block is fixedly connected to the sixth connecting rod; in the initial state, the second connecting rod is in contact with the first limit block; in the initial state, the second finger segment is in contact with the second The limit block is in contact; the center points of the proximal joint axis, the middle joint axis, the distal joint axis, the first axis, the second axis, the third axis, the fourth axis, the fifth axis, the sixth axis and the seventh axis are set to be A, B, C, D, E, F, G, H, I, and J respectively; the lengths of line segment AD and line segment BF are equal; the lengths of line segment BG and line segment CH are equal; the lengths of line segment BC and line segment GH are equal; the lengths of line segment AB, line segment BJ, line segment IJ, line segment BC and line segment AI satisfy: AB:BJ:IJ:BC:AI=100:49:51:68:68; in the initial state, the lengths of line segment AB and line segment DF are equal; in the initial state, the lengths of line segment AB and line segment CJ satisfy: AB:CJ=100:110.

[0007] The differential parallel-link linear flat-clamp dual-finger-segment adaptive robot finger device described in the present invention is characterized in that: the transmission mechanism includes a reducer, a worm and a worm wheel; the output shaft of the motor is connected to the input shaft of the reducer; the worm is fixed on the output shaft of the reducer; the worm wheel is fixed on the first shaft, the worm is meshed with the worm wheel, and the first connecting rod is fixed on the first shaft.

[0008] The differential parallel connecting rod linear flat clamp double-finger segment adaptive robot finger device described in the present invention is characterized in that: the first spring member is a tension spring, a compression spring or a torsion spring; the second spring member is a tension spring, a compression spring or a torsion spring.

[0009] Compared with the prior art, the present invention has the following advantages and outstanding effects:

[0010] The device of the present invention adopts a motor, a transmission mechanism, three finger segments, multiple connecting rods, multiple shafts, two springs and two limit blocks to comprehensively realize the three-joint linear flat clamping and adaptive grasping mode. In the initial stage, the device is in a linear parallel clamping mode: the third finger segment moves horizontally and the trajectory is approximately a straight line, which is suitable for clamping objects on the plane; when the first finger segment is blocked from contacting the object, the device enters an adaptive grasping mode, multiple finger segments contact the object, and it is adaptive to objects of different shapes and sizes. Only one motor is used to drive the three joints, which is simple to control, stable grasping, and low manufacturing and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional appearance diagram of an embodiment of a differential parallel connecting rod straight-line flat clamp double-finger segment adaptive robot finger device designed by the present invention.

[0012] Figure 2 yes Figure 1 A perspective view of the embodiment shown (some parts are not shown).

[0013] Figure 3 yes Figure 1 Front view of the illustrated embodiment.

[0014] Figure 4 yes Figure 3 Left side view.

[0015] Figure 5 yes Figure 3 KK cross-sectional view.

[0016] Figure 6 yes Figure 3 QQ section view.

[0017] Figure 7 yes Figure 1 Rear appearance view of the illustrated embodiment.

[0018] Figure 8 yes Figure 1 A schematic diagram of the principle of a portion of the connecting rod mechanism in the illustrated embodiment (wherein point C moves along an approximately straight line trajectory).

[0019] Fig. 9 yes Figure 1 A schematic diagram of the mechanism principle of the illustrated embodiment.

[0020] Fig.10 yes Figure 1 The illustrated embodiment is a diagram showing the action process of grasping an object in a straight-line flat clamping mode.

[0021] Fig.11 yes Figure 1 The illustrated embodiment is a diagram of the action process of grasping an object in an adaptive mode.

[0022] exist Figures 1 to 11 middle:

[0023] 1-base, 11-motor, 12-reducer, 13-worm,

[0024] 14 - worm wheel, 21 - first finger segment, 22 - second finger segment, 23 - third finger segment,

[0025] 31 - proximal joint axis, 32 - middle joint axis, 33 - distal joint axis, 41 - first connecting rod,

[0026] 42 - second connecting rod, 43 - third connecting rod, 44 - fourth connecting rod, 45 - fifth connecting rod,

[0027] 46 - sixth connecting rod, 51 - first spring member, 52 - second spring member, 61 - first limit block,

[0028] 62 - second stopper, 71 - first axis, 72 - second axis, 73 - third axis,

[0029] 74 - fourth axis, 75 - fifth axis, 76 - sixth axis, 77 - seventh axis,

[0030] 9-Object. DETAILED DESCRIPTION

[0031] The specific structure and working principle of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments.

[0032] An embodiment of the differential parallel connecting rod linear flat clamp double-finger segment adaptive robot finger device designed by the present invention is as follows: Figures 1 to 8As shown, it includes a base 1, a first finger segment 21, a second finger segment 22, a third finger segment 23, a proximal joint axis 31, a middle joint axis 32, a distal joint axis 33, a motor 11 and a transmission mechanism; the motor 11 is fixedly connected to the base 1, and the motor 11 is connected to the input end of the transmission mechanism; the proximal joint axis 31 is sleeved in the base 1, the first finger segment 21 is sleeved on the proximal joint axis 31, the middle joint axis 32 is sleeved in the first finger segment 21, the second finger segment 22 is sleeved on the middle joint axis 32, the distal joint axis 33 is sleeved in the second finger segment 22, and the third finger segment 23 is sleeved on the distal joint axis 33; the center lines of the proximal joint axis 31, the middle joint axis 32 and the distal joint axis 33 are parallel to each other; the differential parallel connecting rod straight line flat clamp double finger The segment adaptive robot finger device also includes a first link 41, a second link 42, a third link 43, a fourth link 44, a fifth link 45, a sixth link 46, a first shaft 71, a second shaft 72, a third shaft 73, a fourth shaft 74, a fifth shaft 75, a sixth shaft 76, a seventh shaft 77, a first spring 51, a second spring 52, a first limit block 61 and a second limit block 62; the center lines of the first shaft 71, the second shaft 72, the third shaft 73, the fourth shaft 74, the fifth shaft 75, the sixth shaft 76, the seventh shaft 77 and the proximal joint shaft 31 are parallel to each other; the first shaft 71 is sleeved in the base 1, and the first link 41 is sleeved on the first shaft 71; the output end of the transmission mechanism is connected to the first link 41; the second shaft 72 The first connecting rod 41 is sleeved in the first connecting rod 41, and the second connecting rod 42 is sleeved on the second shaft 72; the third shaft 73 is sleeved in the second connecting rod 42; the third connecting rod 43 is sleeved on the third shaft 73, and the third connecting rod 43 is sleeved on the middle joint shaft 32; the fourth shaft 74 is sleeved in the third connecting rod 43; the fourth connecting rod 44 is sleeved on the fourth shaft 74; the fifth shaft 75 is sleeved in the fourth connecting rod 44, and the third finger segment 33 is sleeved on the fifth shaft 75; the sixth shaft 76 is sleeved in the base 1, and the fifth connecting rod 45 is sleeved on the sixth shaft 76; the seventh shaft 77 is sleeved in the fifth connecting rod 45, and the sixth connecting rod 46 is sleeved on the seventh shaft 77, and the sixth connecting rod 46 is sleeved on the middle joint shaft 32; the first spring The two ends of the member 51 are respectively connected to the first connecting rod 41 and the second connecting rod 42; the two ends of the second spring member 52 are respectively connected to the sixth connecting rod 46 and the second finger segment 32; the first limit block 61 is fixedly connected to the first connecting rod 41, and the second limit block 62 is fixedly connected to the sixth connecting rod 46; in the initial state, the second connecting rod 42 is in contact with the first limit block 61; in the initial state, the second finger segment 22 is in contact with the second limit block 62; the center points of the proximal joint axis 31, the middle joint axis 32, the distal joint axis 33, the first axis 71, the second axis 72, the third axis 73, the fourth axis 74, the fifth axis 75, the sixth axis 76 and the seventh axis 77 are A, B, C, D, E, F, G, H, I, J respectively; the lengths of the line segment AD and the line segment BF are equal;The lengths of line segments BG and CH are equal; the lengths of line segments BC and GH are equal; the lengths of line segments AB, BJ, IJ, BC, and AI satisfy: AB:BJ:IJ:BC:AI=100:49:51:68:68; in the initial state, the lengths of line segments AB and DF are equal; in the initial state, the lengths of line segments AB and CJ satisfy: AB:CJ=100:110. ;

[0033] In this embodiment, the transmission mechanism includes a reducer 12, a worm 13 and a worm wheel 14; the output shaft of the motor 11 is connected to the input shaft of the reducer 12; the worm 13 is sleeved on the output shaft of the reducer 12; the worm wheel 14 is sleeved on the first shaft 71, the worm 13 is meshed with the worm wheel 14, and the first connecting rod 41 is sleeved on the first shaft 71.

[0034] The differential parallel connecting rod linear flat clamp dual-finger segment adaptive robot finger device of the present invention is characterized in that: the first spring member is a tension spring, a compression spring or a torsion spring; the second spring member is a tension spring, a compression spring or a torsion spring. In this embodiment, the first spring member 51 is a tension spring; the second spring member 52 is a tension spring.

[0035] The working principle of this embodiment is described as follows in conjunction with the accompanying drawings:

[0036] The initial state of this embodiment is as follows Figure 1 , Figure 4 , Figure 5 As shown, the schematic diagram of the mechanism principle is as follows Figure 8 , 9 When performing the grabbing operation in this embodiment, there are two grabbing modes: straight line flat clamping mode and adaptive envelope grabbing mode. They are introduced as follows.

[0037] (1) Straight line flat clamp grabbing mode

[0038] In the initial state of the present embodiment, under the action of the first spring member 51, the second connecting rod 42 contacts the first limit block 61; in the initial state of the present embodiment, under the action of the second spring member 52, the second finger segment 22 contacts the second limit block 62. The motor 11 rotates, driving the worm 13 to rotate through the reducer 12, the worm wheel 14 rotates, the first connecting rod 41 rotates 41 around the first axis 71, the second connecting rod 42 moves through the first spring member 51, and the first finger segment 21 is pushed to rotate around the proximal joint axis 31 through the third connecting rod 43. At this time, due to the action of the second spring member 52, the triangle BCJ maintains its shape unchanged. The principle that the first finger segment 21, the second finger segment 22, the fifth connecting rod 45, the sixth connecting rod 46, the proximal joint axis 31, the middle joint axis 32, the distal joint axis 33, the sixth axis 76, the seventh axis 77 and other parts in the present embodiment make point C move along an approximate straight line trajectory is as follows Figure 8As shown. When line segment AB rotates with A as the center, line segment IJ can be driven to rotate around point I, and point C moves along a trajectory of an approximate straight line S. The center point C of the distal joint axis 33 moves between C1 and C2 to present an approximate straight line trajectory. Thus, the distal joint axis 33 moves along an approximate straight line.

[0039] Because the first limit block 61 is fixedly connected to the first connecting rod 41, under the action of the first spring member 51 and the first limit block 61, the triangle DFE remains unchanged, the line segments DF and AB are equal in length, and the quadrilateral ABFD remains a parallelogram (such as Fig. 9 As shown). Quadrilateral BCHG is a parallelogram (as shown Fig. 9 As shown), the third finger segment 23 maintains an unchanged posture relative to the base during this movement, so the third finger segment 23 moves along an approximately straight line.

[0040] The above process is called the linear parallel clamping (short for linear flat clamping) grasping mode. In this process, when the third finger segment 23 contacts the object, the grasping is completed, thereby realizing the function of linear flat clamping to grasp the object. The action process of flat clamping to grasp the object is as follows: Fig.10 shown.

[0041] (2) Adaptive crawling mode

[0042] During the above-mentioned linear flat clamping movement, when the first finger segment 21 contacts the object first, and the second finger segment 22 and the third finger segment 23 have not yet contacted the object, the first finger segment 21 is blocked and cannot rotate further. At this time, the motor 11 continues to rotate, the first spring member 51 is stretched, the second connecting rod 42 leaves the first limit block, the triangle DEF is deformed, ∠DEF increases, the line segment DF no longer maintains the same length as the line segment AB, and the length of the line segment DF increases, so that the third connecting rod 43 rotates around the middle joint axis 32.

[0043] Since the second finger segment 22, the third finger segment 23, the third connecting rod 43 and the fourth connecting rod 44 form a quadrilateral mechanism, at this time, the second spring member 52 is deformed, and the second finger segment 22 leaves the second limit block 62 until the second finger segment 22 also contacts the object. During the rotation of the third connecting rod 43 around the middle joint axis 32, the third finger segment 23 also rotates around the distal joint axis 33 until the third finger segment 23 also contacts the object. That is: the second finger segment 22 and the third finger segment 23 will rotate around the middle joint axis 32 and the distal joint axis 33 respectively until the second finger segment 22 and the third finger segment 23 also contact the object, thereby realizing adaptive grasping of the object. This process is adaptive to objects of different shapes and sizes. The action process of adaptively grasping an object is as follows. Fig.11 shown.

[0044] The process of releasing an object is the opposite of the above process and will not be repeated here.

[0045] The device of the present invention adopts a motor, three finger segments, multiple connecting rods, multiple shafts, two springs and two limit blocks to realize the three-joint linear flat clamping and adaptive grasping mode. In the initial stage, the device is in a linear parallel clamping mode: the third finger segment moves along an approximate straight line, which is suitable for clamping objects on the plane; when the first finger segment is blocked from contacting the object, the device enters an adaptive grasping mode, multiple finger segments contact the object, and it is adaptive to objects of different shapes and sizes. Only one motor is used to drive the three joints, the grasping is stable, the control is simple, and the manufacturing and maintenance costs are low.

Claims

1. A differential parallel-link linear flat-grip dual-finger segment adaptive robot finger device, comprising a base, a first finger segment, a second finger segment, a third finger segment, a proximal joint axis, a middle joint axis, a distal joint axis, a motor and a transmission mechanism; the motor is fixedly connected to the base, and the motor is connected to the input end of the transmission mechanism; the proximal joint axis is sleeved in the base, the first finger segment is sleeved on the proximal joint axis, the middle joint axis is sleeved in the first finger segment, the second finger segment is sleeved on the middle joint axis, the distal joint axis is sleeved in the second finger segment, and the third finger segment is sleeved on the distal joint axis; the center lines of the proximal joint axis, the middle joint axis and the distal joint axis are parallel to each other; it is characterized in that: The differential parallel-link straight-line flat-grip dual-finger segment adaptive robot finger device also includes a first link, a second link, a third link, a fourth link, a fifth link, a sixth link, a first axis, a second axis, a third axis, a fourth axis, a fifth axis, a sixth axis, a seventh axis, a first spring, a second spring, a first limit block and a second limit block; the center lines of the first axis, the second axis, the third axis, the fourth axis, the fifth axis, the sixth axis, the seventh axis and the proximal joint axis are parallel to each other; the first axis is sleeved in the base, and the first link is sleeved on the first axis; the output end of the transmission mechanism is connected to the first link; the second axis is sleeved in the first link, and the second link is sleeved on the second axis; the third axis is sleeved in the second link; The third connecting rod is sleeved on the third shaft, and the third connecting rod is sleeved on the middle joint shaft; the fourth shaft is sleeved in the third connecting rod; the fourth connecting rod is sleeved on the fourth shaft; The fifth shaft sleeve is arranged in the fourth connecting rod, and the third finger segment is sleeved on the fifth shaft; the sixth shaft sleeve is arranged in the base, and the fifth connecting rod is sleeved on the sixth shaft; the seventh shaft sleeve is arranged in the fifth connecting rod, and the sixth connecting rod is sleeved on the seventh shaft, and the sixth connecting rod is sleeved on the middle joint shaft; the two ends of the first spring member are respectively connected to the first connecting rod and the second connecting rod; the two ends of the second spring member are respectively connected to the sixth connecting rod and the second finger segment; the first limit block is fixedly connected to the first connecting rod, and the second limit block is fixedly connected to the sixth connecting rod; in the initial state, the second connecting rod is in contact with the first limit block; in the initial state, the second finger segment is in contact with the second limit block; set the proximal joint shaft and the middle joint shaft. The center points of the joint axis, distal joint axis, first axis, second axis, third axis, fourth axis, fifth axis, sixth axis and seventh axis are A, B, C, D, E, F, G, H, I and J respectively; the lengths of line segment AD and line segment BF are equal; the lengths of line segment BG and line segment CH are equal; the lengths of line segment BC and line segment GH are equal; the lengths of line segment AB, line segment BJ, line segment IJ, line segment BC and line segment AI satisfy: AB:BJ:IJ:BC:AI=100:49:51:68:68; in the initial state, the lengths of line segment AB and line segment DF are equal; in the initial state, the lengths of line segment AB and line segment CJ satisfy: AB:CJ=100:

110.

2. The differential parallel link straight line flat clamp double-finger segment adaptive robot finger device according to claim 1, characterized in that: The transmission mechanism includes a reducer, a worm and a worm wheel; the output shaft of the motor is connected to the input shaft of the reducer; the worm is sleeved on the output shaft of the reducer; the worm wheel is sleeved on the first shaft, the worm is meshed with the worm wheel, and the first connecting rod is sleeved on the first shaft.

3. The differential parallel link straight line flat clamp double-finger segment adaptive robot finger device according to claim 1, characterized in that: The first spring member is a tension spring, a compression spring or a torsion spring; the second spring member is a tension spring, a compression spring or a torsion spring.

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