EP1621262A1 - Apparatus for handling, particularly sorting, of bulk material - Google Patents

Abstract

A continually-operated industrial mechanical handling assembly has a conveyer system for different types of bulk solid object and a camera directed at the passing objects. The camera is linked to a computer and recognises and distinguishes between the different types of object and is coupled to a pick-up system. The camera distinguishes between the bulk solid objects on the conveyer as they pass with no relative motion between the bulk solids. The pick-up system subsequently releases the bulk solid objects into sorted or classified groups.

Description

The present invention relates to an apparatus and method for gripping and manipulating bulk solids with a powered gripping tool. The invention relates in particular to the sorting of such bulk material parts, if they are mixed in any way.

In commercial and industrial practice, the problem often occurs to grab and manipulate individual mass-produced parts with driven gripping tools. In the following, we talk about bulk goods, which means that smaller and medium sized parts are processed in relatively large quantities. The parts do not necessarily have to be equal to each other. Rather, an important aspect of the invention is directed to sorting such bulk material parts. In particular, this may involve sorting according to group membership, in which case mixed bulk goods are sorted in such a way that these groups are not initially separated, but after sorting, in each case specific groups are separated from one another. In this case, even in the sorted groups, the parts do not necessarily have to be equal to one another, but only fulfill common criteria in some way.

By the term bulk material is further meant that the considered parts are present in a relatively disordered, so not oriented to the position and orientation of the individual part way or be transported. It should certainly also include those parts that show a certain mechanical sensitivity and therefore can not be safely "poured", but with a certain caution in quantities and disorderly stored and transported can.

In particular, it is known to sort such parts in the manner roughly outlined below: The parts are stored in bulk in a bulk container, i. disorderly stacked in the amount stored, taken from this container in the lower area and promoted via a vibrating table. This vibrating table executes directed vibrations, which causes the bulk material to move along the table. When a certain number of parts are spread on the table, the vibrations are interrupted and a driven gripping tool, specifically a robot arm, picks out the individual parts. The robotic arm proceeds sorting, thus manipulating the gripped parts depending on their group affiliation or, depending on the group affiliation, leads the parts to various transport devices for onward transport.

The robot arm is controlled by a camera system, which optically records the parts on the table with a camera and programmatically determines their group affiliation, position and orientation. Thus, it is controlled, which position the robot arm anfährt, ie where parts of which group are, and how he grips the parts properly. If the operated by the robot arm area of the transport table is empty or there are still parts that are either not to be grasped or could not be recognized correctly by the camera system, the table is possibly vacated empty and filled in the manner described with other parts.

Advantages of this method are that parts of a certain size class can be sorted by reprogramming the camera system with the same device, even if the part geometry fundamentally changes.

It is also known, bulk material parts on geometrically cleverly designed Sort transport devices by means of harassment. Such baffles are designed so that they bring the parts on the one hand in a specific orientation for onward transport or "sort out" incorrectly oriented parts, ie in the process bring it back to earlier place. The same applies to the same or other chicanes for parts of certain groups, ie it is transported on a group-dependent basis or not. The transport devices are usually vibration paths.

The advantages of such solutions are, above all, the large achievable throughput and the low control engineering effort.

The present invention is based on the technical problem of providing an advantageous device and an advantageous method for gripping and manipulating isolated bulk material parts, which on the one hand are flexible and on the other hand allow a favorable throughput.

The invention is directed to a device for gripping isolated bulk material with a driven gripping tool, which device a conveyor for conveying the parts, a camera system for optically detecting the parts located on the conveyor, the gripping tool for gripping and manipulating the optically detected and on the För -dereinrichtung located parts, which gripping tool is controlled by the camera system, and is characterized in that the device is designed to promote bulk goods with the conveyor in relative rest position together conveyed parts with each other, thereby recognize and thereby grab,

and to a corresponding method for gripping isolated bulk material parts with a driven gripping tool, which method is carried out by means of a device according to one of the preceding claims and comprising the steps of: conveying the parts with the conveyor, optically detecting the parts located on the conveyor with the Camera system, grasping and manipulating the optically detected and located on the conveyor parts with the gripping tool, wherein the gripping tool is controlled by the camera system, characterized in that bulk material parts promoted to each other in relative rest position, thereby recognized and thereby gripped.

Preferred embodiments are specified in the dependent claims and are explained in more detail below. The individual features relate in each case both to the device category and to the method category of the invention, without this being distinguished in detail.

The essential aspect of the invention is to design the conveyor so that the bulk material parts are conveyed in a certain phase relative to each other in rest position. This allows the camera system to perform the optical detection during conveyance. However, if the parts were moved on a vibrating table or the like relative to each other, this would not be possible or only with great effort. Further, during this collective movement, during which they move relative to the device as such, but not relative to one another, the parts are to be gripped by the gripping tool. Thus, a certain simultaneity of conveying, recognizing and gripping can be achieved.

This simultaneity should be present at least for substantial parts of the processing. However, the invention does not exclude that the conveyor is stopped in certain situations, such as when so many parts in a position suitable for gripping and / or (in the application of the invention for sorting) belonging to the group to be gripped parts have been detected, that the gripping tool in view of the number of these parts does not get along with the time available on further promotion.

In a preferred embodiment of the invention, at least the If the gripping tool is operated continuously, it is at best possible to interrupt the conveying movement. This is in contrast to the described prior art, in which the gripper tool or the robot must pause in the time phases in which the vibrating table is emptied and / or refilled. In this regard, the invention thus provides efficiency benefits.

As with the described prior art, it is also preferred in the context of this invention to use a robot as a driven gripping tool. Articulated arm robots with a certain number of rotary robot axes can be particularly favorable. Another very cheap option is multi-arm robots, especially hexapods. In these, the arms are connected to a gripper part and can move this very quickly and three-dimensionally by expansion and contraction of the arms. In the general sense, however, the term "gripping tool" means any form of powered or power gripping tool including hydraulic and pneumatic cylinder drive.

Further, it is preferred, as in the described prior art, to convey the parts from a bulk container, i. a container in which the parts are disordered and in height one above the other, so to speak heaped stored.

Further, the conveyor may be configured so that it "back promotes" of the gripping tool unrecognized parts, that brings back to another area of the conveyor from which they are again promoted in the area in which the gripping tool engages. This can be used to initially promote gripping or recognizing unfavorable parts another time in a new position. It can also serve to avoid or reduce the already described interruptions of promotion because of currently too large numbers of parts to be gripped. Finally, this can also be part of a sorting process Thus, parts of certain groups can be systematically left behind and promoted back.

A preferred embodiment of the conveyor is a belt conveyor or has a belt conveyor. Such a belt conveyor has the advantage of great flexibility in terms of size, shape and weight of the parts to be conveyed. The conveyor belt can also be structured, for example having surface structures such as knobs or grooves, in order to stabilize the position of the parts somewhat and thus to suppress adverse movements for the recognition. For example, For example, screws on the side of a round head could easily roll on a smooth conveyor belt, but could find a stable position on knobs or grooves. But there may be other or complementary structures, especially if the conveyor belt is not horizontal, such as ribs, stop bars, brush-like sections or a continuous brush-like structure and the like. Thus, a movement due to the inclination of the tape can be prevented and also the acquisition of the parts are supported by another conveyor or from a container. Adhesion can also be increased with a silicone coating.

In one embodiment, such a belt conveyor can easily throw off the mentioned non-gripped and returned parts, such as another belt conveyor (or other conveyor) or the original bulk material container. This is particularly simple, because only care must be taken that under the corresponding end of the belt conveyor, the other conveyor or the container is arranged. Incidentally, instead of the end of the belt conveyor for discharging, a place may be used where the belt conveyor is rotated about an axis parallel to its direction of conveyance and the parts are thrown laterally. This can be especially for reasons of space advantage.

Another embodiment is of two belt conveyors of Conveyor, wherein the first belt conveyor promotes the parts of the bulk material container, then transfers to the second belt conveyor, on which the parts are recognized and gripped. Preferably, at least the portion of the first belt conveyor, which receives the parts on the bulk goods container (preferably obliquely) arranged upward running and thereby passes through the bulk material in the container. The parts can then be received, for example, by stop strips or other of the mentioned structures.

The transfer from the first to the second belt conveyor can be done by simply dropping. The throwing off has here, and incidentally, also in the discarding of the non-gripped parts at the end of the second belt conveyor, in addition to the simplicity of the advantage that a dropping of the parts with a higher probability that they go into a position in the the focus is low. On the one hand, such positions are preferred because the parts are then more stable. Secondly, there is a smaller number of possible positions. For example, the camera system and the gripping tool could also be designed so that they can only detect and / or grasp parts in such positions. But it can also be used stop strips or the like to cause such positions, for example, overturn longer upright parts. Ultimately, it is clear that the use of harassment in the invention is not excluded. However, chicanes have the fundamental disadvantage of reducing the flexibility of the device in a more specific embodiment. It is then possibly no longer possible to process a completely different part geometry with a similar part size with the same device, while merely adapting the programming of the camera system and the gripping tool control.

After all, discarding often also makes sense to share more singulate or separate, which are promoted, for example, during discharge from the container in still entangled or at least superimposed manner.

For similar reasons, a vibrating plate may be provided in front of or at the second belt conveyor or in principle in front of or below a belt conveyor. This is arranged on the side facing away from the parts, so the lower side of the tape and makes the tape to vibrate. The vibrations should not serve or not only for conveying as in the prior art but for singling and for producing relatively stable layers of the parts. The vibration plate may, for example, include a suction device with which the tape is sucked onto it to ensure an efficient vibration transmission. The suction device may also be provided in the vicinity of the vibrating plate.

In principle, a device according to the invention can also have a plurality of conveying devices, camera systems and / or gripping tools. In detail, it must be judged which component of the device has a time-limiting effect. For example, it may be beneficial to work with two or more cameras to make the capture process more efficient. There may also be a division of tasks between the camera systems, for example by each being aligned with a specific group or a certain number of groups. If the gripping tool, in particular the robot, works particularly quickly or grips, in particular should sort, which are expediently conveyed, for example because of presorting, with different conveying devices, then a plurality of conveying devices can "share a gripping tool". In this case, a radial arrangement around a gripping tool, in particular an articulated robot or hexapods, is preferred, which can be imagined in a manner similar to a roundhouse with a rotary switch, that is, above all does not have to be closed in a star shape.

Finally, it may also be preferable to use a plurality of gripping tools in order to increase the overall throughput or to make a better adaptation to specific groups in terms of programming or geometry.

As already mentioned above, it may be advantageous in the invention to perform a presorting. The invention can thus be associated with simple chicanery devices, so that the sorting according to the invention takes place only among those groups which can be distinguished badly with chicanes. Above all, it has been common in the prior art to pour parts of different groups together in one and the same bulk goods container and thus to cancel a preselection originally existing with regard to the delivery, ie to mix the parts. Here, the invention proposes instead to start from a corresponding number of bulk containers or to use a corresponding number of conveyors to maintain the presorting. In this case, the conveyors would thus be supplied with bulk goods, which are still mixed insofar as there is a plurality of groups to be sorted. However, the group mixtures of different conveyors should not match. Thus, either no common groups should occur or at least not all groups should be common so that the respective devices can be configured accordingly.

In the following the invention will be explained in more detail with reference to two embodiments, which are shown in the figures in side view and highly schematic. The individual features disclosed here are, on the one hand, essential both with regard to the device category and the method category of the invention and, on the other hand, can also be essential to the invention in other combinations.

Figure 1 and Figure 2 each show an embodiment in a schematic side view.

FIG. 3 shows a third exemplary embodiment as a detail and with reference to FIG. 2.

Figure 4 shows a fourth embodiment in a highly schematic plan view.

FIG. 5 shows a variant of FIG. 1 as a fifth exemplary embodiment.

Figure 1 shows a side view of a first embodiment of a device according to the invention. With 1 a shown as a simple box bulk material container is located, which is open at its top and is filled with not shown here bulk material by dumping. In the lower right area of the bulk material container 1 is traversed by a first belt conveyor 2 with a belt 3, which has obliquely adjusted abutment edges 4 on its outside. The abutment edges 4 access the bulk material from the bulk material container 1 and promote it obliquely upward. There, the conveyor belt 3 of the first belt conveyor 2 is deflected with a roller 5 in the horizontal. Further to the right, the conveyor belt 3 is again deflected by a further roller 6, which rests in the direction perpendicular to Figure 1 in front of and behind the abutment edges 4, in the vertical, then redirected once again in the roller 7 designed as roller 7 back and finally led back over another three pulleys 8, 9 and 10.

The parts are thus conveyed to the strand between the deflection rollers 7 and 8 and thrown there in consequence of the angle of the conveyor belt 3 and the abutment edges 4 on a second belt conveyor 11. The second belt conveyor 11 extends horizontally and slightly above the horizontal run of the first belt conveyor 3 between the pulleys 5 and 6. It is spanned between two rollers 12 and 13 and carries on its upper side in Figure 1 schematically indicated bulk material parts in FIG 1 from right to left. In the right area of the upper run a vibrating plate 14 is mounted under the belt, the separated parts separated by vibrations and accidentally tip over upright parts. The vibrating plate 14 has for this purpose a suction device, not shown, in order to better transfer the vibrations to the belt can. In Figure 1, left of the vibrating plate 14, a further fixed plate 15 is arranged. Also, the plate 15 includes a suction device and ensures that the vibrations do not extend to the rest of the strand, so that the individual parts are transported quietly in the course.

The strand is also in the remaining area, as indicated by the dashed line 21, supported and supported.

Above the left of the fixed plate 15 with the suction device subsequent part of the upper run of the second belt conveyor 11, two cameras 16 and 17 are arranged, which optically detect the parts on this strand from above. The cameras 16 and 17 each form, with a computerized evaluation device, a camera system which controls an articulated-arm robot 18, which is symbolically drawn on the left, with a gripping tool 19 moved thereon. The gripping tool 19 can be moved up and down along an axis 20 and rotated and grip the individual bulk material parts in a manner not shown in detail. It is raised and lowered accordingly and rotated. Incidentally, it is moved horizontally two-dimensionally with at least two other Gelenkarmachsen, which are not shown here.

The camera systems of the cameras 16 and 17 share the task of optical detection of the bulk material in the present case in such a way that each camera system for a type occurring, ie a group, is responsible. After a coarse presorting in size, each camera system determines only position and Orientation of the respective group and controls the articulated arm robot 18 so that the gripping tool 19 accesses in the correct orientation at the right place.

Ungripped parts are transported further to the left and fall down to the left of the guide roller 12 on the horizontal run of the first belt conveyor 2, so that they are thrown back in the manner already described on the second belt conveyor 11.

Figure 2 shows a second embodiment. There, a bulk goods container 30 is shown on the right, which can also be filled from an open top. From this bulk material container 30 runs approximately at 45 ° obliquely upward, a first belt conveyor 31 out, which is clamped between two rollers 32 and 33. The band of the belt conveyor 31 carries transverse ribs 34 which hold the bulk material. The bulk material is dropped in the region of the roller 32, on a second belt conveyor, which corresponds to the second belt conveyor 11 of Figure 1 and is therefore also designated. It is spanned between the rollers 12 and 13 and has in the same way the already explained plates 14 and 15 and the support structure 21. The comments on the first exemplary embodiment also apply to the cameras 16 and 17 of the corresponding camera systems and the articulated-arm robot 18.

The non-gripped parts are in turn dropped in the area of the roll 12, in this case on a third belt conveyor 35 between two rollers 36 and 37. This is used exclusively for the return of these parts in the bulk material container 30, which by dropping in the right roll 37 happens.

Incidentally, the bands of the second belt conveyor 11 in FIGS. 1 and 2 may, for example, be studded in order to allow a stable position of smaller parts. In the present case, rather flat parts are drawn where this is not necessary. For parts that are already stable For example, such structured ribbons may also have the disadvantage of giving rise to a number of tilted positional possibilities that would not occur on flat ribbons and complicate the gripping and accurate positioning by the robot. The conveyor belts can be coated, for example even with an inclined course, as in the case of the first belt conveyors 2 and 31, for example with silicone.

Below Figure 2, an alternative with respect to the vibrating plate 14 is drawn as a third embodiment in Figure 3 schematically. The arrows indicate, as in Figures 1 and 2, the conveying direction. In this embodiment, the first belt conveyor 31 throws in the region of the roller 32, the bulk material on a vibrating table 38 on which the parts are first isolated and brought to tip over. Secondly, the vibrations of the vibration table 38 are directed so that the parts are transported to the left to fall down in the area of the roller 13 on the second belt conveyor 11. For the sake of simplicity, the device of this third exemplary embodiment is otherwise not drawn and corresponds to FIG. 2. A corresponding variation of the first exemplary embodiment from FIG. 1 is, of course, conceivable without further ado.

FIG. 4 shows a schematic plan view of the articulated arm robot from FIG. 2 with its articulated arm and the axis 20 attached to the distal end of the articulated arm with the not-shown gripper tool 19. This articulated arm robot, as a fourth exemplary embodiment, is located centrally in a radial arrangement of four devices of the type Figure 2, sharing only a common robot. The devices are shown only schematically, wherein each of the bulk goods container 30 are numbered at the radially outer end.

Figure 5 shows a fifth embodiment, which completely corresponds to the first embodiment except for the robot. In that regard, reference is made to the description.

The articulated arm robot 18 with the gripping tool 19 and the axis 20 is here replaced by a hexapod 40, 41, in which a number of six (only three drawn) thrust arms 40 are connected to a common gripper part 41. The gripper part 41 can manipulate parts in a manner known per se similar to the gripping tool 19 from FIG. Incidentally, reference is made to the prior art to hexapods. This is a particularly fast, control-technically demanding robot class.

Of course, a combination of a hexapod 40, 41 with the exemplary embodiments illustrated in FIGS. 2 to 4 is also possible.

Claims (15)

Device for gripping isolated bulk material parts with a driven gripping tool (18-20), which device comprises: a conveyor (2, 11, 35) for conveying the parts, a camera system (16, 17) for optically detecting the parts located on the conveyor (2, 11, 35), - The gripping tool (18-20) for gripping and manipulating the optically detected and on the conveyor (2, 11, 35) located parts, which gripping tool (18-20) is controlled by the camera system (16, 17),
characterized in that the device is designed to convey bulk goods with the conveyor (2, 11, 35) in relative rest position together promoted parts with each other,
to recognize it
and grab it. Apparatus according to claim 1, wherein the driven gripping tool is a robot, in particular an articulated arm robot (18-20) or a hexapod. Apparatus according to claim 1 or 2 with a bulk material container (1, 30) in which the bulk material parts are stored in heaps, wherein the conveyor (2, 11, 35) is adapted to convey the parts of the bulk material container. Device according to one of the preceding claims, in which the conveying device (2, 11, 35) is designed to move parts not gripped by the gripping tool (18-20) during the gripping of parts into a region (2, 35) of the conveying device (2 , 11, 35), from which they can be conveyed again by the conveying device (2, 11, 35) for gripping by the gripping tool (18-20). Device according to one of the preceding claims, in which the conveying device has a belt conveyor (2, 11, 35). Apparatus according to claim 4 and 5, which is adapted to not Drop the gripped parts through the belt conveyor (11). Apparatus according to claim 3 in combination with claim 5 or 6, comprising a first belt conveyor (2, 31) for conveying the parts from the bulk material container (1, 30) and a second belt conveyor (11) to which the parts from the first belt conveyor (11) 2, 31) and on which the parts can be recognized and gripped. Apparatus according to claim 7, wherein the first belt conveyor (2, 31) is arranged so that it can convey bulk material in the bulk material container (1, 30) out of the bulk material container by means of abutment edges or brush-like structures on the belt conveyor while the abutment edges (4, 34) or brush-like structures are moved upwards along the parts in the bulk material container (1, 30). Apparatus according to claim 7 or 8, wherein the first belt conveyor (2, 31) is adapted to drop the parts onto the second belt conveyor (2, 31). Device according to claim 7, 8 or 9, wherein the second belt conveyor (2, 31) has a vibration plate (14) arranged on the side of the belt facing away from the parts or arranged upstream of the belt conveyor (11). Device according to one of the preceding claims, comprising a plurality of conveyors (2, 11, 35) arranged radially around at least one central gripping tool (18-20). Method for gripping isolated bulk material parts with a driven gripping tool (18-20), which method is carried out with the aid of a device according to one of the preceding claims and includes the steps: Conveying the parts with the conveyor (2, 11, 35), optically detecting the parts located on the conveyor (2, 11, 35) with the camera system (16, 17), - Grasping and manipulating the optically detected and located on the conveyor (2, 11, 35) parts with the gripping tool, wherein the gripping tool (18-20) of the camera system (16, 17) controlled becomes,
characterized in that bulk material parts in relative rest position promoted to each other,
recognized
and be gripped. The method of claim 12, wherein the bulk material parts are similar in groups and sorted by gripping. Method according to claim 13 using a plurality of devices according to claim 1, in which the bulk material parts are presorted in advance to the conveyor (2, 11, 35), in that each conveyor (2, 11, 35) comprises a plurality of groups of identical parts However, the groups of different conveyors (2, 11, 35) are not identical to each other. The method of claim 12, 13 or 14, which is continuous with respect to the gripping tool (18-20).

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