CN209954695U

CN209954695U - Apple picking manipulator

Info

Publication number: CN209954695U
Application number: CN201920257102.XU
Authority: CN
Inventors: 杨福增; 樊攀; 雷小燕; 孙景彬; 孟宠
Original assignee: Northwest A&F University
Current assignee: Northwest A&F University
Priority date: 2019-02-28
Filing date: 2019-02-28
Publication date: 2020-01-17
Anticipated expiration: 2029-02-28

Abstract

The utility model provides an apple picking manipulator can satisfy the apple and pick, snatch under stable prerequisite, can solve technical problem such as current apple picking manipulator structure complicacy, manufacturing cost height. The picking manipulator is provided with two joint fingers, the fingers are fixed by a spiral spring and then are installed on a palm disc, each finger consists of two knuckles, a driving connecting rod and a driven connecting rod, a tendon rope on the driving connecting rod penetrates through the palm disc and then is vertically fixed on a lifting disc, and the other end of the lifting disc is connected with a driving motor through the tendon rope. Through motor drive, tendon rope transmission, drive the finger and gather together, realize that 3 fingers of drive are accomplished by a motor simultaneously and snatch the envelope of apple.

Description

Apple picking manipulator

Technical Field

The utility model relates to an agricultural robot picks the field, especially indicates a simple structure, control are convenient, pick efficient apple picking manipulator device, belongs to the supplementary device technique of picking of agricultural.

Background

The apple cultivation area and the apple yield are the first in China all over the world, and the apple cultivation area and the apple cultivation yield are traditional dominant export products. In apple production, picking operation is the most time-consuming and labor-consuming link. At present, the apple picking operation is mainly completed manually, a large amount of labor force is needed, the industrial development causes a large amount of rural labor force loss, meanwhile, the problems of low efficiency, high cost, large labor amount and the like exist along with the aging of social population, and with the development of computer technology, artificial intelligence technology and automatic control technology, the robot gradually enters the field of agricultural production, so that the apple picking robot becomes an important requirement of modern agricultural production. The picking manipulator is a part which is arranged at the front end of a mechanical arm of the picking robot and is directly operated, and the appearance of the apple is fragile, so that the operation of the picking manipulator is directly related to the accuracy and the high efficiency of the whole picking operation of the picking robot, and the design of the picking manipulator is considered to be one of the core technologies of the agricultural robot.

Certain research is developed in the field at home and abroad, for example, Baeten in Belgium creates a picking manipulator for picking apples by vacuum suction, wherein the picking manipulator is an apple-shaped silica gel funnel and is used as a mouth of a vacuum cleaner, but the picking manipulator has poor adaptability and low stability to apples with different sizes; the apple of 3 fingers of thunberg university's gold wave team development manipulator is picked, step motor drive, is furnished with the screw drive pair that nut and screw rod cooperation formed, and then the motion inwards of drive finger through the transmission of connecting rod, realizes snatching the apple, and it adopts three joint design modes, and the configuration number of snatching as weighing to snatch stable important index is the relation that becomes the exponential change with the joint number, snatchs the configuration more and appears the contact point and break away from more easily, is difficult to stabilize more.

Disclosure of Invention

The utility model aims to solve the technical problem that the manipulator structure is complicated, the control degree of difficulty is big, defects such as manufacturing cost height are picked to apple among the prior art, propose an apple picking manipulator, through motor drive, tendon rope transmission has realized that two joint fingers by 3D printing ABS plastics preparation snatch to the envelope of apple, have reduced finger joint number when guaranteeing to snatch stability, and three fingers only are furnished with a driver simultaneously, have simplified the structure, the cost is reduced.

In order to achieve the above purpose, the present invention adopts the following technical solution.

A manipulator device for picking apples is characterized in that fingers are composed of a two-joint under-actuated mechanism and comprise a near knuckle (6) and a far knuckle (1), each finger is provided with a driving connecting rod (4) and a driven connecting rod (2), three hinge holes distributed in a certain proportion are formed in the driving connecting rods (4), one end of each hinge hole is hinged to one end of the driven connecting rod (2), the other end of each hinge hole is connected with a tendon rope (10), the included angle of the two end holes is 35 degrees, and the middle part of each hinge hole is hinged to the near knuckle (6) and a knuckle support (8) together; two ends of the driven connecting rod (2) and two ends of the near knuckle (6) are respectively provided with a groove, two ends of each groove are provided with hinge holes, and the notches are all provided with fillets; the far knuckle (1) is arranged to be a right triangle, the two end faces of the included angle between the hypotenuse and the right-angle side are removed to form cuboids with equal sizes and then are hinged with the driven connecting rod (2), and the other end of the included angle is hinged with the hinge hole of the near knuckle (6); the finger can not interfere with each component in work.

Furthermore, three knuckle supports (8) and three spiral springs II (7) are uniformly distributed on the palm disc (9) at a central angle of 60 degrees: the knuckle support (8) has a certain height, so that the driving connecting rod (4) can move up and down in a certain range under the driving of the tendon rope (10) and cannot interfere with the palm disc (9); the spiral spring II (7) is connected with the lower part of the driving connecting rod (4), has certain rigidity, can enable the fingers to be in a flaring shape in a natural state, can be stretched in work, and can be restored to the flaring shape after grabbing is finished. The spiral spring I (3) is connected with the upper part of the driving connecting rod (4) and the back of the near knuckle (6), so that the driving connecting rod (4) can provide auxiliary power for the near knuckle (6) to enable the near knuckle to move centripetally when the finger works, and the driving connecting rod (4) can force the near knuckle (6) to move centrifugally to enable the near knuckle to reset when the finger works.

Furthermore, the near knuckle (6), the far knuckle (1), the driving connecting rod (4) and the driven connecting rod (2) form two-joint fingers, a four-connecting-rod mechanism is adopted in a transmission mode, the four-connecting-rod mechanism has the advantages of being high in efficiency, large in holding force and the like, and a spiral spring is adopted as a power and reset mechanism.

Furthermore, 3 small holes are uniformly distributed on the palm disc (9) and the lifting disc (15) respectively, the small holes on the palm disc (9) are through holes, and the opening position of each through hole can enable the tendon rope (10) connected with the driving connecting rod (4) to vertically fall and not to contact with the through holes; the small holes in the lifting disc (15) are bolt holes, the tendon ropes (10) falling vertically are fixed through the bolts, and the bolts are used for adjusting the tension degree when fixing the tendon ropes (10), so that the picking manipulator cannot contact the tendon ropes (10) and the through holes under various working conditions.

Furthermore, the geometric center of the lower surface of the lifting disc (15) is also provided with a bolt hole, one end of the tendon rope (10) is fixed through the bolt hole, and the other end of the tendon rope is vertically and uniformly wound on a groove of the pulley (13) after falling.

Furthermore, pulley (13) are fixed in the pivot of driving motor (12), have one section invariable eccentricity between tendon rope (10) and the pivot, are tangent in the recess all the time, are provided with certain tensile force to guarantee tendon rope (10) and vertical lift disc (15) center under any operating mode, and lift disc (15) can not take place to rock.

Further, the driving motor (12) is fixed on the base (11).

Furthermore, soft silica gel pads are covered on the inner side surfaces of the near knuckle (6) and the far knuckle (1) so as to prevent the apple epidermis from being damaged.

Furthermore, pressure sensors (5) are arranged on the inner side surfaces of the near knuckle (6) and the far knuckle (1) to acquire the grabbing force in the picking process at any time.

Compared with the prior art, the utility model discloses an advantage lies in with positive effect:

the utility model provides an apple picking manipulator device, three fingers two joints finger reduce the finger joint number of traditional picking manipulator, simplified the device structure, make and snatch the control more nimble to accomplish and palm snatch similar motion mode through tendon rope (10) and coil spring mechanism control finger, structural design is ingenious, control is nimble, low in production cost.

Drawings

Fig. 1 is a schematic view of the overlooking structure of the picking manipulator of the present invention.

Fig. 2 is a schematic view of the connection structure of the palm plate, the lifting disc and the motor of the present invention.

Fig. 3 is the structural schematic diagram of the picking manipulator of the utility model showing the open finger when facing the apple.

Fig. 4 is the utility model discloses an apple structure sketch is snatched in picking manipulator envelope.

Fig. 5 is a schematic diagram of the finger structure of the picking manipulator of the present invention.

Detailed Description

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, 3-5, three two-joint fingers with the same structure are taken as an example for introduction, the two-joint fingers are composed of a near knuckle (6), a far knuckle (1), a driving connecting rod (4) and a driven connecting rod (2) which are connected in series, one end of the driving connecting rod (4) is hinged with one end of the driven connecting rod (2), the other end of the driving connecting rod is connected with a tendon rope (10), the included angle of two end holes is 35 degrees, and the bent driving connecting rod (4) enables two ports on the driving connecting rod to have larger rotation stroke in the direction vertical to a palm disc (9); the middle part is hinged with the near knuckle (6) and the knuckle support (8) together, the other two ends of the driven connecting rod (2) and the near knuckle (6) are hinged with the far knuckle (1) respectively to form a four-connecting-rod finger structure, and the spiral spring I (3) connected between the driving connecting rod (4) and the near knuckle (6) can provide auxiliary power when the near knuckle (6) rotates towards the apple (16); in order to prevent interference between the mechanisms of the two joint fingers, the following measures are taken in the embodiment: the knuckle support (8) is arranged at a certain height under the condition of ensuring normal picking; the two ends of the proximal knuckle (6) and the driven connecting rod (2) are provided with U-shaped clamping grooves, and the bottoms of the grooves are rounded corners.

The shape adaptability of fingers to objects is generally in direct proportion to the number of joints, however, the number of the grabbing configurations which are important indexes for measuring the grabbing stability is in an exponential change relationship with the number of joints, the more the grabbing configurations are, the more the contact points are easy to separate, and the more the grabbing is difficult to stabilize. In the present embodiment, the purpose of the design is to grip the apple as the final executing device, so the gripping stability becomes more important. The embodiment improves the traditional multi-joint picking manipulator, reduces the number of finger joints, adopts the four-bar mechanism to realize combined transmission, not only improves the grabbing stability, but also has convenient control and flexible movement.

Referring to fig. 2, three knuckle supports (8) and a spiral spring II (7) are uniformly distributed on a palm disc (9) at a central angle of 60 degrees, a driving connecting rod (4) and a near knuckle (6) are hinged with the knuckle supports (8) according to corresponding hinge holes, and in a natural state, no matter a picking manipulator is in a horizontal or inclined state, the rigidity of the spiral spring II (7) is enough to ensure that three fingers are stretched outwards integrally, and meanwhile, under the cooperation with a driving motor (12), a tendon rope (10) and a lifting disc (15) cannot shake; when the three-finger-type lifting appliance works normally, the driving force of the driving motor (12) overcomes the rigidity of the spiral spring II (7), the three fingers rotate towards the apple (16), and the tendon rope (10) and the lifting disc (15) cannot shake.

Referring to fig. 3, in the process of facing the apple (16), the three fingers are in a natural state, are wholly outwards expanded and have a flaring structure, so that the apple (16) can be conveniently accommodated; tendon rope (10) are fixed with lifting disc (15) after 3 small holes are uniformly distributed on the palm disc and vertically fall down, one end of tendon rope (10) is connected with the geometric center of the lower surface of lifting disc (15), the other end of tendon rope freely falls and winds on a groove of pulley (13), certain tension is provided for initial state of tendon rope (10), pulley (13) is fixed on a rotating shaft of driving motor (12), and when driving motor (12) works, tendon rope (10) is uniformly wound on the groove of pulley (13).

Referring to fig. 4, when the picking manipulator works, a motor rotating shaft overcomes the resistance of a coil spring ii (7) to drive a pulley (13) to rotate, a tendon rope (10) is contracted, a lifting disc (15) moves downwards, a driving connecting rod (4) is driven by the tendon rope (10) to rotate in a centering manner by taking a middle hinged hole as a center of a circle, a coil spring i (3) deforms to push a near knuckle (6) to rotate around a knuckle support (8) until the near knuckle (6) contacts an apple (16), and the near knuckle is restrained by the contact closing force, and the degree of freedom is restrained, meanwhile, a far knuckle (1) is changed into a working degree of freedom by a driven connecting rod (2) under the driving of the driving connecting rod (4), the far knuckle (1) is folded in a centering manner and contacts the apple (16), and a containing cavity containing the apple (16) is finally formed, so that the centering movement of fingers is; soft silica gel pads are covered on the inner side surfaces of the proximal knuckle (6) and the distal knuckle (1) so as to prevent the surface of the apple (16) from being damaged; pressure sensors (5) are arranged on the inner side surfaces of the near knuckle (6) and the far knuckle (1) to acquire the grabbing force in the picking process at any time, when the force reaches a required value, a signal is fed back to the driving motor (12), and the driving motor (12) stops working.

Claims

1. The utility model provides an apple picking manipulator which characterized in that: the device comprises two joint fingers, a spiral spring, a palm disc (9), a tendon rope (10), a pulley (13) and a driving motor (12), wherein the two joint fingers are respectively supported on the palm disc (9) through knuckle supports (8); one end of the tendon rope (10) is connected with a finger, and the other end of the tendon rope penetrates through the palm disc (9) and then is vertically fixed on the lifting disc (15); one end of the tendon rope (10) is fixed at the center of the lifting disc (15), and the other end is connected with the pulley (13); the pulley (13) is assembled on the rotating shaft of the driving motor (12); the driving motor (12) is fixed on the base (11).

2. A picking manipulator according to claim 1, characterised in that: two joint fingers are provided with nearly knuckle (6), far knuckle (1), drive connecting rod (4) and driven connecting rod (2), nearly knuckle (6), drive connecting rod (4) middle part hinge hole and knuckle support (8) are articulated jointly, be equipped with coil spring I (3) between nearly knuckle (6) and drive connecting rod (4), be equipped with coil spring II (7) between drive connecting rod (4) and palm dish (9), driven connecting rod (2) are articulated with drive connecting rod (4) one end, far knuckle (1) both ends are articulated with nearly knuckle (6) and driven connecting rod (2) respectively.

3. A picking manipulator according to claim 2, characterised in that: three knuckle supports (8) of equipartition on palm dish (9), there are 3 articulated holes on drive connecting rod (4), have 35 contained angles between two end holes, set up to crooked connecting rod, and wherein one end is articulated with driven connecting rod (2), and one end is connected with tendon rope (10) in addition.

4. A picking manipulator according to claim 3, characterised in that: three small holes are uniformly distributed on the palm disc (9), and the tendon ropes (10) are fixed with the lifting disc (15) after vertically falling through the small holes uniformly distributed on the palm disc (9).

5. A picking manipulator according to claim 4, characterised in that: a bolt hole is formed in the geometric circle center of the lower surface of the lifting disc (15), one end of the tendon rope (10) is fixed with the bolt hole through the bolt, the other end of the tendon rope falls vertically and is uniformly wound with a groove in the pulley (13), the falling direction coincides with the central shaft of the lifting disc (15) and is tangent to the pulley (13), and the pulley (13) is fixed on the rotating shaft of the driving motor (12).

6. A picking manipulator according to claim 1 or 2, characterised in that: the inner side surfaces of the near knuckle (6) and the far knuckle (1) are covered with soft silica gel pads, damage to the apple in the grabbing process is reduced, and the pressure sensors (5) on the near knuckle (6) and the far knuckle (1) can feed back the clamping force.

7. A picking manipulator according to claim 6, characterised in that: the rotating speed of the driving motor (12) is controlled according to the pulse frequency of the motor, the pressure sensor (5) obtains the contact force of each finger, when the finger surface pressure sensor (5) reaches the set grabbing force, a signal is fed back to the driving motor (12), the driving motor (12) stops moving, and the apple grabbing is achieved.

8. A picking manipulator according to claim 1, 2 or 4, characterised in that: the finger, the supporting rod, the knuckle support (8), the palm disc (9), the lifting disc (15) and the base (11) are all made of 3D printing ABS plastic.