Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
VISION APPLIANCE FOR ROBOTS
Document Type and Number:
WIPO Patent Application WO/2014/181246
Kind Code:
A1
Abstract:
The vision appliance (1) for industrial robots, comprises: at least a supporting frame (3), which can be fixed to a jointed arm (2) of the robot, and suitable for supporting a grip means (4); and a vision unit (8, 9), which includes at least an image acquisition device (9) and at least a lighting device (8), the unit (8, 9) being retractably mounted on the frame (3).

Inventors:
PASSONI LUCIANO (IT)
Application Number:
PCT/IB2014/061231
Publication Date:
November 13, 2014
Filing Date:
May 06, 2014
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
SIR SOC ITALIANA RESINE SPA (IT)
International Classes:
B25J19/02
Foreign References:
EP2511055A12012-10-17
US20080163403A12008-07-03
US20100298978A12010-11-25
EP0537923A21993-04-21
US5602967A1997-02-11
Other References:
None
Attorney, Agent or Firm:
LUPPI, Emanuele (Via Scaglia Est 19-31, Modena, IT)
Download PDF:
Claims:
CLAIMS

1) Vision appliance (1) for industrial robots, comprising at least a supporting frame (3), which can be fixed to a jointed arm (2) of said robot, and suitable for supporting a grip means (4); characterized in that it comprises a vision unit (8, 9) which includes at least an image acquisition device (9) and at least a lighting device (8), said unit (8, 9) being retractably mounted on said frame (3),

2) Appliance (1) according to claim 1, characterized in that said unit (8, 9) is movable between a work position in which it protrudes from said frame (3), so as to define the maximum perimeter dimensions of said appliance (1), and a rest position in which it defines the minimum perimeter dimensions of said appliance (1).

3) Appliance (1) according to one or more of the preceding claims, characterized in that said acquisition device (9) is mounted on board of said lighting device (8).

4) Appliance (1) according to claim 2 or claim 3, characterized in that said frame (3) has an inner housing able to receive said unit (§? 9) in said rest position.

5) Appliance (1) according to one or more of claims 2, 3 or 4, characterized in that it comprises movement means (22, 23, 26, 27) for translating said unit (8, 9) between said work position and said rest position..

6) Appliance (1) according to claims 4 and 5, characterized in that said frame (3) comprises two substantially plate-shaped and parallel elements (20, 21), placed at a reciprocal distance such as to define said housing (19) and in that said means are suitable for translating said unit (8 , 9) in a plane parallel to said elements (20, 21 ) ,

7) Appliance (!) according to one or more of the preceding claims, characterized in that said lighting device comprises at least a luminous panel (8).

8) Appliance (1) according to one or more of the preceding claims, characterized in that said acquisition device comprises at least a camera (9).

9) Appliance (!) according to claim 7 and 8, characterized in that said panel comprises a seat (11) which houses said camera (9). I.0) Appliance (1) according to claim 9S characterized in that said seat (1 1) is arranged central to the panel (8).

11) Appliance (1) according to claim 3 and to one or more of claims from 5 to 10, characterized in that said movement means (22, 23, 26, 27) comprise at least a pneumatic cylinder (22, 23) mounted on said frame (3), having a stem (24, 25) the distal extremity of which is fixed to said lighting device (8).

12) Appliance (1) according to claim 3 and one or more of the claims from 5 to

I I, characterized in that said movement means (22, 23, 26, 27) comprise at least a linear guide (26, 27), mounted between said frame (3) and said lighting device (8).

13) Appliance (1) according to one or more of the preceding claims, characterized in that it comprises, fixed below the frame (3), an automatic tool- changing device (7, 70) for robots.

Description:
VISION APPLIANCE FOM ROBOTS

Technical Field

The present invention relates to a vision appliance for industrial robots.

Background Art

Industrial robots for de-palletizing, e.g. of the anthropomorpliie type, are know which are equipped with a jointed arm which supports a grip means, in correspondence of its distal extremity.

The grip means are often of the suction type, substantially plate-shaped, and are arranged to pick up an entire layer of products at a time from the pallet.

Each layer is placed by the robot on a support, such as a pallet.

A major limitation of this solution is the fact that it does not allow to pick up individual products.

Therefore, the layer removed by the robot roust be fractionated manually by personnel in charge, so that the different products can be sent to their respective destinations.

This system is very slow, inefficient and very expensive mainly because of the necessity of the use of labor.

Nevertheless, it continues to be used for the following reasons.

The products are distributed and arranged in the respective layers in different positions and directions depending on their size * number and size of the pallet. Furthermore, for space reasons, they are placed adjacent to one another, within the same layer.

Consequently, the layers of different pallets, and eventually different layers of the same pallet, may have a different configuration, that is to say that they may comprise products arranged in a different way from those of other layers or other pallets.

Therefore, even the conventional industrial robots that comprise grip means able to grip the individual product, e.g. of the gripper type, are not usable to de- palletize products individually,, since the control unit to wiiich these means are subject is not informed about the specific arrangement of products within the respective layers.

Consequently, this unit can not control the robot so as to be able to take the product in the correct maimer, and to pick it up without damaging or arranging other products badly,

To solve this problem, robots have been provided which are equipped with vision means, such as cameras, e.g. mounted on grippers.

This solution may work in part for certain types of products, but also has at least two drawbacks.

First, it is not suitable for use for single-product pallets of slrraik-wrapped packs of plastic bottles.

Indeed, this is not able to detect in a satisfactory wa the arrangement of the slirink-wrapped packs of bottles in one layer of the pallet, because the shrink film, that wraps the bottles in the related shrink-wrapped packs, produces reflections and shadows that prevent to effectively distinguish the boundary between a shrink-wrapped pack and another.

in addition, the dimensions of said vision means prevents the use of this known solution for transferring products between different pallets, which is instead a need currently felt in the logistics industry serving large retail chains.

In fact, it happens frequently that on destination pallets are formed walls of products, made up, in practice, of a stack of products that protrudes upward into the pallet.

The products subsequently loaded on the destination pallet must often be placed adjacent to one of these walls, and this can not be done by a robot that carries the vision means described above, because these, due to their dimensions, would eventually bump the wall and drop to the ground the products already loaded.

Description of the Invention

The main aim of the present invention is to provide a vision appliance for industrial robots that allows to detect the individual arrangement of the products comprised in one of the layers of a pallet,

Within Ibis aim, one object of the present invention is to provide a vision appliance for industrial robots which allows to palletize (and in particular re- palletize) products on a destination pallet, also when walls of products have formed on this. Another object of the present invention is to provide a vision appliance for mdustriai robots which allows to overcome the above mentioned drawbacks of the prior art in the ambit of a simple, rational, easy and effective to use as well as low cost solution.

The objects described above are achieved by the present vision appliance for industrial robots according to claim I .

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become evident from the description of a preferred, but not exclusive, embodiment of a vision appliance for industrial, robots, illustrated by way of an indicative, but not limitative, example in the accompanying drawings in which:

Figure 1 is a side view of a robot that mounts the vision appliance according to the invention;

Figure 2 is a top plan view of the vision appliance according to the invention; Figure 3 is a side view of the vision appliance according to the invention, wherein the vision unit is in its rest position;

Figure 4 is a side view of the vision appliance according to the invention, wherein the vision unit is in its work position;

Figure 5 is a side view of said robot, when the appliance is used on source pallets;

Figure 6 is the detail K of the previous figure;

Figure 7 is a view from below of the appliance according to the invention; and Figure 8 is a side view of the robot, while it is used to load a shrink-wrapped pack on a destination pallet,

Embodiments of. the Invention

With reference to these figures, globally indicated by 1 is the vision appliance of the invention ,

The invention has been devised for use with an industrial robot, in particiiiar of the anthropomorphic type, equipped with at least three (but preferably six.) degrees of freedom, and comprising a jointed ann indicatively represented in the figures by its distal joint 2.

In detail, the appliance 1 may be fixed in correspondence of the distal extremity of the arm, in this case to said joint 2.

This fixing can be implemented by means of releasable fastening means, such as bolts or the like (as in the example shown in the figures), or by means of an automatic tooi-clmnging device for robots.

At any rate, as shown in Figure 1, the proposed appliance 1 comprises firstly a supporting frame 3, which is the part that can be fixed to the jointed ami 2 and able to support a grip means 4.

In particular, the invention is especially intended to support a pneumatically operated gripper 4 for robots, e.g. of the type having a fixed jaw 5 and a movable jaw 6.

in detail, the proposed appliance 1 may provide, feed below the frame 3 and interposed between this and the gripper 4, an automatic tool-changing device 7, 70 for robots (shown in detail in Figure 6).

The automatic tool-changing devices are well known in the industry and are generally composed of two coupling devices 7, 70, often with a substantially discoid shape, each fixed to one of the two components intended to be joined, configured in such a way to attach the components in a releasable way, and to (also) connect the distal component both to the operating means (e.g. of the pneumatic or hydraulic type) and to the electronic control unit of the robot, thanks to suitable electronic connectors equipped with usual pins or other similar systems.

In the configuration shown in the enclosed drawings, the gripper 4 represents the true end effector of the robot 2, where the appliance 1 of the invention is incorporated in the distal portion of the jointed arm 2.

However, alternative configurations are possible.

Preferably, the joint 2, the appliance 1. and the gripper 4 extend along an axis A which, in use, is arranged vertically.

Below, for illustrative convenience, we will refer to the set composed of joint 2, appliance 1 and gripper 4 as a robot vision and handling operating group.

The invention, in its broader aspects, comprises a lighting device 8, carried by the frame 3 and an image acquisition device 9, directly supported by the lighting device 8, to define a vision unit 8, 9. In detail, the acquisition device 9, which may be a camera or a film camera, is fixed to the lighting device 8 with a direction such, as to "see" (i.e., acquire images of) an area illuminated by the lighting device 8.

Preferably, the acquisition device 9 is mounted on board of the lighting device 8, in a manner best explained later.

According to an important aspect of the invention, the lighting device 8 is retractably mounted on the frame 3.

In particular, in the preferred embodiment of the invention, the lighting device 8 (and, in more detail, the vision unit 8, 9) is movable between a work position, in which it protrudes, substantially cantilevered, from frame 3, and a rest retracted position.

To be precise, when the vision unit is in the work position (the condition shown in Figures 2, 4, 5 and 6), d e appliance Ϊ has its maximum perimeter dimensions, while when it is in its rest position, it defines the minimum perimeter dimensions of the appliance 1 (see Figures 1 5 3 and 7).

Note that the expression "cantilevered" identifies the position of the vision unit 8, 9 when the aforementioned operating group 2, !, 4 is in the arrangement of use, wherein said axis A is arranged vertically.

In particular, in its work position, the vision unit 8, 9 protrudes cantilevered from the whole operating grou 1, 2, 4, and m detail it is arranged in an external half-space E defined by a front plane P parallel to the axis A of the operating- group, while in the rest position it is placed in the other lialf-space I, i.e. the internal one (see in particular Figure 4).

in the remainder of the present description, for reasons of clarity of explanation, the parts of the operating group 2, 1, 4, or of other entities specified below, which are facing or at least closer to the above mentioned plane P, will be characterized by the adjective "front" or "frontal"; e.g., the jaw 5 facing to the plane P, will hereinafter be called "front jaw" 5.

The opposing parts,, further from the front plane P, will be referred to as "rear". In the preferred embodiment of the invention, the lighting device comprises at least one luminous panel 8, e.g. of quadrangular shape, having a luminous face 10, from which is emitted the light produced by it. When the vision unit 8, 9 is in the work position and the operating group 1, 2, 4 is in the arrangement of use, then the luminous face 10 is facing downwards, and therefore also the acquisition device 9 must be directed so as to take the objects placed below.

For this purpose, the panel 8 can comprise a seat I I to accommodate the acquisition device 9, which is preferably a through housing able to receive the lens 12 of the camera or film camera.

This measure allows to contain the overall dimensions of the vision unit 8, 9, because this has a substantially planar extension, with perimeter dimensions only defined by those of the luminous panel 8,

Advantageously, the seat 11 may be arranged in the panel 8 in a central position, the latter thus having a substantially annular shape,

The luminous panels are known per se, though, not in combination with the other components of the invention, and may include a plurality of LED lamps, substantially coplanar and evenly distributed.

Before describing fkrther constructive and functional aspects of the invention, the operation of the proposed appliance 1 is explained, by referring, for convenience of explanation, to its preferred embodiment and its use for de- palletizing (and possibly re-palletizing) shrink-wrapped packs of plastic bottles. The shrink-wrapped packs 1.4 to be picked up are presented on a source pallet, in a top layer 13, accessible from above.

The robot is operated so as to bring its operating group 1, 2, 4 at the pallet, substantially above the top layer 13, in the aforesaid arrangement of use.

Initially, the vision unit. 8, 9 is in the rest configuration shown e.g. in Figure L Then, the unit 8, 9 is operated (through the means explained below) so as to protrude firontally beyond the vertical plane P up to the work position.

In this situation, the luminous panel 8 and the camera 9 protrude, preferably entirely, with respect to the group 1, 2, 4 and are located directly facing to said top layer 13, without the interposition of any shielding,

In particular, the panel 8 is arranged horizontally, parallel to the top layer 13, with the above luminous face 10 placed in front of the layer 13,

In this case, clearly, the lens 12 of the camera 9 is pointed towards the layer 13 of shrink- wrapped packs,

At this point the panel 8 and the camera 9 are activated in such a way to illuminate, respectively, the layer 13 from above a d to take the upper face of the shrink-wrapped packs, which is struck by the light.

Especially in the case where the lens 12 of the camera 9 is arranged centrally with respect to the panel 8, given that the light projected from this strikes the top of the shrink- wrapped packs 14, according to a multiplicity of angles, starting from different points of origin evenly distributed all around the lens 12, then the image taken by the latter does not have any reflections and shadows which can distort the boundaries between a shrink-wrapped pack 14 and the other,

Consequently, using special computer programs able to process the images, the processing unit of the robot is able to detect the arrangement and mutual direction of the shrink- wrapped packs 14 of the layer.

In this manner, this unit can then control the jointed arm 2 and the gripper 4 in order to pick up a shrink-wrapped pack 14 at a time from the layer 13.

At this point, the vision unit 8, 9 can return to its rest position,

The operating group 1, 2, 4, after picking up the shrink-wrapped pack 14, can approach the destination pallet 15,

Advantageously, the robot mounting the appliance 1 of the invention can place the picked up shrink-wrapped pack 14 in a loading position in the destination pallet 15 that is adjacent to a wall of products 16, which was referred to in the description of the background art.

In fact, as clearly visible in Figure 8, if the loading phase of the shrink- wrapped pack 14 is performed carefully by arranging the group 1, 2, 4 so that the jaw 5 closest to the wall 16 is the frontal one, it is clear that the vision unit 8, 9 can not strike the wall 16 and can not cause the fall of products making it up, The load of the shrink-wrapped pack 14 can be performed by placing it first in an inclined configuration, wherein its perimeter sides are oblique with respect to the wall 1 , and wherein it contacts the pallet 15 only along a comer 17 thereof defined in correspondence of the lower edge of the rear side 18 (the furthest from the front plane P), in such a way that the comer 17 is substantially parallel to the wall 16.

After that, the shi'ink- wrapped pack 14 is made to rotate towards the wall 16, to be arranged with the perimeter sides parallel to the wall 16 and rest freely in said loading position.

In any case, the arrangement of the luminous panel 8 in the rest position must be suitably chosen by the person skilled in the art, depending on the configuration of the robot, the joint 2, the gripper 4 and the type of product being handled, so that the panel 8 does not contact the wall 16 when laying the shrink-wrapped pack 14 or other product on the destination pallet 15.

In detail, the frame 3 can be advantageously provided with an inner housing 19 able to receive the vision unit 8, 9, when it is in the rest position.

In this case, the unit 8 5 9 can be mounted concealed in the frame 3, namely that, in the rest position, the panel 8 and the camera 9 are contained substantially entirely in the housing 1 of frame 3 (see, e.g. Figure 1).

This measure is particularly advantageous because it allows to reduce dimensions to a muranum, at least in front of the proposed appliance 1, especially if implemented together (and i synergy) with the measure of posi tioning the camera 9 on board of the luminous panel 8.

In particular, the frame 3 may generally have a parallelepiped shape and a box- shaped configuration, and may comprise two substantially plate-shaped, parallel and superimposed elements 20, 21, w f hich are placed at a reciprocal distance such as to define, between them, said housing 19.

In particular, these elements are perpendicular to said axis A, and are arranged so that one of these elements, the upper one, defines the ceiling 20 of the frame 3 and is secured to the joint 2 mentioned several times, while the other element defines the bottom 21 of the frame and is secured to said automatic tool- changing device 7, 70,

In tliis case, the lighting panel 8 is accommodated in the housing 1 , parallel to the ceiling 20 and to Hie bottom,

For this purpose, the frame 3 may have at least the front thick side open, to allow r the entry and exit of the vision unit 8, 9 into/from the housing 19 preferably by translation. For this purpose, as mentioned above, the proposed appliance I comprises movement means 22, 23, 26, 27 for shifting the vision unit 8, 9 between the work position and the rest position.

The movement means may comprise at least a pneumatic cylinder 22, 23 (but preferably two, as shown in the figures) mounted on the frame 3, having a stem 24, 25, the distal and front extremity of which is fixed to the lighting panel 8 (see Figures 2 S 3, 4 and 7).

Furthermore, the movement means may comprise at least a linear guide 26, 27 to cooperate with the cylinder 22, 23, mounted between the frame 3 and the panel 8 , and able to constrain the latter in its transnational motion.

In detail, two guides 26, 27 may be provided which also have a bearing function.

In fact, to the rear of panel 8 may be fixed two members 28, 29 substantially copJanar to It preferably prong-shaped.

The rails 26, 27 of the guides may be fastened both above the panel 3 and above the prongs 28, 29, connecting them at the top. The rails 26, 27, the panel 3 and the prongs 28, 29 connected this way, define a slide between them which is monnted slidably on the frame 3, so as to be supported by the frame itself.

In particular, the rails 26, 27 can engage slidably shoes 30 fixed to the frame, In this ease, also the rear thick side of the frame 3 is preferably open, so as to allow the free sliding of said prongs 28, 29 whose length may not be contained in the above housing 19.

It has been found, in practice, how the described invention achieves the intended objects and in particular the fact is underlined that it provides a vision appliance 1 that comprises a retractable vision unit 8, 9 which allows to determine the mutual arrangement of the products in a layer of a pallet and allows to load a product on a different pallet even In the presence of walls of products.