Patent Application
20080040911
The invention relates to a robot cell for changing and storing elements with a unique property, such as tools and/or products, comprising:
In modern day industry there is an increasing degree of automation, inter alia by integrating product and/or tool changers in various types of processing machines. Such changers have a limited capacity and in the case of substantial changes in the processes to be carried out will have to be provided with additional or replacement products and/or tools from outside the machine with which they are associated. In most cases this can be performed automatically by a robot. For instance, robots are used to change products and tools in CNC processing machines. However, these robots are restricted to performing a few, repetitive operations. Stocking of the tool and product changers can be done from a magazine. The magazine and the robot then form a so-called robot cell. One disadvantage of such a robot cell is that the magazine has to be equipped depending on the machine, and often depending on the manufacturer as well, because the tool and product changers for different types of processing machines and from different manufacturers each have their own requirements and demands. As a consequence of this the life of the robot cell is linked to the life of the processing machines, for example CNC processing machines, whilst the intrinsic economic life of the robot cell is longer. Therefore, when replacing processing machines a new robot cell also has to be purchased, which is associated with appreciable additional costs.
U.S. Pat. No. RE 37 622 describes a method and an installation for polishing wafers. The wafer polishing installation comprises a wafer input/output module and a wafer processing module. In the input/output module use is made of a loading robot. The loading robot removes wafers, which are supplied in input cassettes, one by one and places them on an alignment unit. After alignment, a gripper unit places the aligned wafer on a loading point presented at the input location of an index table. This index table will then rotate. The points on which the wafer has to be placed are fixed on the index table and are filled on the basis of availability at the input location.
U.S. Pat. No. 6,157,866 describes a system for automatic handling of material in a production environment, which is subdivided into separate production areas. Robots that are used in this system temporarily place a wafer at a fixed location. In the article entitled “Robot handling on machine tools” by Müller et al., Industrial & Product Engineering 12 (1988) pp 72-74, 77, an automated system for making gearbox components is described, where use is made of four integrated robots, each of which is installed in a robot cell. Each robot cell is adapted to the specific task it performs. U.S. Pat. No. 4,543,636 describes a digitally controlled installation for arranging a tool magazine consisting of a magazine for storing a multiplicity of tools and a stock magazine. When a product to be processed is supplied, the requisite tools are supplied as input to a processor on the basis of a programme of operations to be carried out. This processor develops a tool change programme so that all tools that are needed for processing the product are stored in the magazine for storing a multiplicity of tools.
Finally, U.S. Pat. No. 4,845,835 in the name of Erowa AG describes a robot cell that is capable of changing and storing tools and/or products in an effective manner.
The above installations are not equipped to provide a flexible response to process and/or product changes. Each element has a fixed location within the installation. A change of machines and/or products means a change of elements. In such a case the installation has to be adapted or replaced, which is associated with high costs. Because each user imposes specific requirements, almost every robot cell will furthermore be custom-made, which is associated with high production costs and installation costs.
The aim of the present invention is to provide a robot cell that does not have these disadvantages. Said aim is achieved with a robot cell as described above in that in the robot cell the at least two locations in the magazine section are each suitable for storing elements with a different value for the unique property and the robot cell is set up to select a suitable location in the magazine section when an element with a unique property is placed in the interchange station. A robot cell according to the present invention can be organised flexibly. This can be coupled to various types of processing machines, each of which require different elements, and is furthermore capable of adapting its organisation effectively in the case of a process or product change.
A unique property can comprise parameters such as height, length, width, mass, etc., but can also relate to other properties of the element, for example the shape of the latter. It must be understood that it is possible that several elements with the same unique property are stored in the robot cell. On the basis of this corresponding unique property, the robot cell will select a suitable location of the same type, if available, in the magazine section.
In one embodiment, the robot cell comprises a memory for the selection of a suitable location in the magazine section, which memory contains a first and a second database, and a first processor for computing a suitable location for an element placed in the interchange station on the basis of data from the first and second database, wherein the first database contains data with regard to the unique property of the element placed and the second database contains data with regard to whether or not locations in the magazine section are occupied, as well as the suitability per location for storing an element with a specific value for the unique property. By making use of these databases, the processor can relatively easily select a suitable position for a new element to be placed.
In a further embodiment, the robot cell comprises a measurement device. As a result of the presence of this measurement device the robot cell is even better able to function independently. The measurement device can, for example, a height of the element placed. The measurement device can rapidly supply the requisite data for effective selection by the robot cell.
In one embodiment, the element placed is provided with a data carrier and the robot cell has a reader that can read the data carrier. Such a combination of measures makes it possible to obtain a large amount of information rapidly with regard to the element to be placed. The reader is preferably installed on the robot. In this way the robot can easily process properties which, for example, are of importance when handling the element.
In the abovementioned embodiments, the element can be placed on or in a storage unit. This makes it possible to subdivide the robot cell into units easily, and thus increases the flexibility.
In one embodiment, the robot cell is furthermore provided with an element changer. This element changer makes it possible to replace elements that are broken or worn with the aid of the robot, without the storage unit, with any other elements thereon, having to be changed.
In all embodiments, the robot cell can furthermore be provided with a cleaning device. Such a cleaning device can help to prevent malfunctions in the robot cell and processing errors in the machines to a minimum by limiting contamination of the robot cell and the elements present therein.
The invention further relates to a combination of one or more industrial machines and a robot cell according to the present invention. The one or more industrial machines can be CNC processing machines.
The invention furthermore relates to a method for changing and storing elements with a unique property in a robot cell, which comprises a robot, around at least part of which a wall has been installed, which is provided with an interchange station and which on the inside has a magazine section with at least two locations, wherein the at least two locations in the magazine section are each suitable for storing elements with a different value for the unique property, the method comprising:
Detection can be effected by means of reading a data carrier that is affixed to the element to be placed by means of a reader or by means of measuring a height of the element with a height measurement device.
In one embodiment if two or more locations are equally suitable the processor selects a lowest location. In this way a structured organisation of the robot cell can be achieved.
In one embodiment, the property is a height and, if the height exceeds a predetermined threshold value, if two or more locations are equally suitable the processor selects a highest location. In this way high elements can be placed in the robot cell without taking up an exceptional amount of space, for example if there is no roof construction.
In the abovementioned embodiments of the method, the element can be placed on or in a storage unit. This makes it possible to subdivide the robot cell into units easily and thus increases the flexibility.
In the abovementioned embodiments, the method can comprise defragmentisation of the robot cell with the aid of the processor to create new locations. By combining gaps between successive stored elements, which gaps are in themselves too small to accommodate an element, one or more new locations can be created.
The invention will be further explained below by way of example on the basis of the following figures. The figures are not intended to restrict the scope of the invention, but merely to illustrate the latter. In the figures:
a-b show a side view and a plan view, respectively, of a storage unit provided with tools;
a-b show a side view and a plan view, respectively, of a storage unit provided with a product holder with products;
The robot cell 1 comprises a robot 3 and a number of magazine sections 4, which can be installed around the robot 3 such that a polygonal wall structure is obtained. The robot 3 is preferably a 4- or 6-joint robot, such as, for example, described in the above-mentioned U.S. Pat. No. 4,845,835 in the name of Erowa.
The magazine sections 4 can be provided with folding means which ensure that a magazine section 4 is able partially or entirely to fold, preferably outwards, in order to provide direct linking between a machine 2 to be served and the robot cell 1 and to facilitate the exchange of elements.
The arrangement of magazines in the robot cell 1 can therefore be partly dependent on the number of machines 2 that have to be served, the positioning of these machines with respect to the robot cell 1 and the surface area of a magazine section 4 that is used to provide direct transfer of elements between machine 2 and robot cell 1, per coupled machine 2.
The robot cell 1 furthermore has an interchange station 5 and an element changer 6. Each magazine section 4 has a number of locations, in this case distributed over the height, where storage units, provided with elements such as products to be processed or tools, can be placed. The storage units can be transported via the interchange station 5 into and out of the robot cell 1. Changing of tools and optionally also products can, in addition, also be effected via the element changer 6. The storage units and/or elements that are to be newly placed or to be changed can be placed in the interchange station 5 from the outside either manually by an operator or automatically with the aid of a robot.
The robot cell 1 has a computer that is preferably connected to an input panel 7 and a display 8. An operator can enter commands, such as entering new data with regard to the tasks that the machines 2 have to carry out, via the input panel 7. The display 8 can display various data, such as the status of the contents of the robot cell 1, the progress of the processes that are carried out by the robot cell 1 and any process conditions, such as temperature and pressure. The computer can be so equipped that it controls not only the robot cell 1 but also the machines 2 that are served by the robot cell 1. However, it is also possible that the machines 2 function independently, that is to say stand-alone.
The robot cell 1 can furthermore be provided with a measurement device for measuring one or more unique properties of the storage units and/or elements to be placed or to be changed. Such unique properties can be parameters such as height, length, width, mass, etc. However, it is also possible that the unique property relates to the shape of the elements and/or storage units to be placed or to be changed. In the description below a unique property is referred to as a property. Preferably, the measurement device is positioned in the opening of the interchange station 5, but such a device can also be accommodated in other locations, for example inside the robot cell 1.
The robot cell 1 according to the present invention furthermore has a processor and at least one memory. These can be installed in the computer 4, which is connected to the input panel 7 and the display 8, but can also be installed in another computer that is linked to computer 4. On the basis of data from the at least one memory, the processor selects a location where a storage unit with load, that is to say provided with one or more elements to be newly placed or to be changed, can be placed. These data comprise data with regard to one or more properties of the storage unit with load and/or individual elements that have been placed thereon and to be newly placed or to be changed, as well as data with regard to the available locations within the robot cell 1.
The data with regard to the identity of the load that has been placed on the storage unit can be entered manually by an operator or in some other way from outside into the memory of the computer 4 of the robot cell 1. The data with regard to one or more properties of the storage unit with load to be newly placed or to be changed can be entered in an identical manner, but are preferably obtained via the measurement device.
a-b show a side view and a plan view, respectively, of one example of a storage unit 10 provided with tools 11. The storage unit 10 is shaped such that this can be placed in various positions in a magazine section 4. A magazine section 4 can contain one or several storage units 10. The precise number is dependent on the number of locations per magazine section 4 and the properties, in particular the height, of each storage unit 10 with load.
a-b show a side view and a plan view, respectively, of one example of a storage unit 10 provided with a product holder 12 with products 13 on top of it. The products 13 can be either already processed or unprocessed.
Apart from the product holder 12, products 13 and tools shown in
The majority of components to be placed, that is to say both each storage unit 10 and elements, such as product holders 12, gripper units, tool holders and/or tools 11, placed thereon are preferably provided with a data carrier. Products 13 could also be provided with a data earner. However, the fact that the products 13 are subjected to one or more treatments, where there is the risk that the data carrier could be damaged or destroyed, reduces the added value of such a data carrier.
A data carrier contains data relating to at least one property of the element to which this is affixed. For instance, the data carrier can contain information with regard to the height of an element and in the case of the storage unit 10 in
In the case of the presence of data carriers on the components, the robot cell 1 is preferably provided with a reader, which is preferably installed on the robot 3. Before picking up the storage unit 10 for storage in the robot cell 1, the robot 10 can detect the positions in which the individual elements that have been placed on the storage unit 10 are located.
If the elements are not provided with a data carrier or if the data carriers contain no or too little information on the elements, such as information relating to their height and/or mass, one or more properties of the elements can be obtained by making use of the measurement device. One example of such a measurement device is the height measurement device 16 that is shown in
In
Furthermore, the robot cell 1 is preferably provided with a cleaning device 18. Contamination is a major problem in an industrial environment. If it is desired to guarantee the desired accuracies both with regard to positioning in the robot cell 1 and with regard to processing in the machines 2, it is then important that the products to be processed and processed products, as well as the tools 11 used, are adequately cleaned. Contamination of these elements can lead, inter alia, to malfunctions in the robot cell 1 and processing errors in the machines 2.
The cleaning device 18 is arranged in the robot cell 1 such that the robot 3 is able to bring the elements, which, for example, are used or are processed by the machines 2, into contact with it before they are store. This can take place, inter alia, by allowing the elements to remain in the cleaning device 18 for some time or by moving the elements one or more times through the cleaning device 18 with the aid of a movement executed by the robot 3. In
On entry to the robot cell 1 via the interchange station 5 the data carriers affixed to new elements can be read by the reader 20. The data read are then stored in an element database 21. Which elements together form a group is preferably also stored. If necessary, data can be entered via an input station, for example the input panel 7 of the computer, in both the location database 22 and in the element database 21. With the aid of the data from the two files 21, 22, a processor 23 then selects a suitable location where the group of new elements can be placed. For instance, in the case where one of the data from element database 21 relates to a height of the combination of storage unit 10 and one or more elements 11, 12, 13, the processor can search in the location database 22 for locations where a combination with that height can be placed. The selected location is then sent by the processor 23 to the control unit 24 of the robot 3. Finally, the control unit 24 ensures that the robot 3 is moved the new group of elements from the position in the interchange station 5 to the location selected by the processor 23. Placing of the new group of elements can have consequences for surrounding locations that have not yet been filled, with regard to their suitability for storing and/or changing of an element with a specific value for the one or more properties. Any changes in said suitability per location that are produced by placing are therefore entered in the location database 22 by the processor 23 after placing.
A similar procedure takes place if a processing machine 2 requires an element for a process to be carried out. Suppose, for example, that a machine requires a drill T1 and the computer requests that this be picked up from the correct magazine section. Suppose that drill T1 is provided with a chip C100 and is positioned on a storage unit 10 that is provided with a chip C1. In a manner as described above, the processor 23 of the computer of the robot cell 1 has selected a suitable location for this storage unit 10 with drill T1 and the robot 3 has placed the storage unit 10 concerned in the selected location. The correlation between location as stored in the second database 22 and the data as read by a read unit 20 from the chips C1 and C100 and stored in the first database 21 is also known.
When the computer of the robot cell 1 receives the request from the machine 2 for drill T1, the processor 23 makes use of the above known data and correlations. After all, it is known that there is a T1 in the robot cell 1 that has been positioned on a specific storage unit 10. The position of the element on the storage unit 10 concerned is possibly also recorded. The location of this specific storage unit 10 in the robot cell 1 is also known.
The processor 23 of the computer gives the control unit 24 of the robot 3 the command to pick up the drill T1 concerned, or the relevant storage unit 10 on which the drill T1 is located, and to provide this, for example via the interchange station 5, or if there are folding means, via the opening produced between robot cell 1 and machine 2 when these are folded out, to the requesting machine 2. The robot cell 1 preferably functions not so much as an implementer of commands on the basis of requests received from machines 2, but rather as an independent distributor of elements to associated machines 2 on the basis of process commands which it gives itself and which are entered in the computer of the robot cell 1 via the input panel or in some other way. There is then a so-called master-slave relationship between the robot cell 1 and the machine(s) 2. In this case the robot cell 1 (master) assigns the process commands to be carried out to specific machines 2 (slaves) and preferably assigns a specific priority to each process command. A machine 2 that is carrying out a process command with a higher priority then receives preferential treatment compared with a machine 2 that is carrying out a process with a lower priority, with regard to stocking with elements from the robot cell 1 that are needed for the process to be carried out. Both techniques that can be used to set up a master-slave relationship between robot cell 1 and machine(s) 2 and techniques for processing parallel commands of different priority are known to those skilled in the art.
In addition to the changing or placing of storage units 10 with load via the interchange station 5, in one embodiment of the invention it is also possible to change individual elements via an element changer 6, as shown in
If the majority of elements, that is to say product holders 12, tool holders, gripper units and tools 11 are provided with data carriers, the element changer 6 is preferably also provided with a reader 20. The reader 20 can read the data carrier and send it to a spare element database (not shown), which is also connected to processor 23. The processor 23 now compares the data read from the spare element database for the element to be newly placed with the data from element file 21 for the element to be replaced. If no differences are found, or if the differences remain below predetermined threshold values, the processor issues the command to place the element in the location selected by the processor 23 to the control unit 24 of the robot cell 1. The control unit 24 will in the majority of cases make the robot 3 place the new element in the location of the element that has been removed. If the differences found are too great and the new element thus has one or more properties which render positioning in the location of the element that has been removed impossible, the robot 3 will not place the element immediately. There are a number of possibilities in this case. By making use of the stored data per element in the element database 21 and the data in the location database 22 with regard to the location in which these elements were placed, the processor 23 can assign an alternative location for the element to be newly placed. In some cases it is also possible that the processor 29 indicates that the robot 3 has to change storage unit 10 for a number of elements, such as tools 11, within the robot cell. However, it is also possible that the processor 23 sends an error signal to, for example, the display 8 or to another component of the robot cell 1 using a signal function, for example a special signal lamp. The error can be reported by means of one or more signal types, such as error messages, audio signals or light signals.
In one embodiment the measurement device comprises, for example, a height measurement device 16 as shown in
The robot cell 1 furthermore also contains a location database 22. The locations in the robot cell 1 that are empty and those that are filled are maintained in the location database 22. At the start all locations are unoccupied. The data stored in the location database 22 thus indicate that all locations are available. Preferably, the location database 22 maintains which locations are occupied.
To enable the robot 3 to place the group of new elements in the correct location within the robot cell 1, in step 33 the data from the element database 21 and the location database 22 are combined and fed to a processor 23. On the basis of the at least one property detected, such as a height of the new group of elements, and on the basis of the available space in the robot cell 1, this processor 23 selects a suitable location within a magazine section 4 and sends this to the control unit 24 of the robot 3. The at least one property detected can be determined immediately via a measurement device 16, but can also be computed by the processor 23 on the basis of data entered externally or individual data stored on a data carrier and read by a reader 20. In step 34 the robot 3 then places the group of new elements concerned in the location determined by the processor 23. Finally, the selected location for the new group of elements is sent either after step 33 by the processor 23 or after step 34 by the control unit 24 to the location database 22. In step 35 the newly filled location is then stored in the location database 22.
The element database 21 can be designed in various ways. If a measurement device 16 is used, as shown in
Apart from the abovementioned properties, there are yet further circumstances with which the processor 23 can take account when determining a location. For instance, it is preferable to fill an empty magazine section 4 from bottom to top. In this case a storage unit 10 to be newly placed in an empty magazine section 4 is assigned a location at the bottom of the magazine section 4. It can also be determined that if specific properties exceed a predetermined threshold value, for example the case where the combination of storage unit 10 and load is higher than a predetermined height, the combination to be newly placed is preferably placed at the top of the at least one magazine section 4. In this way, especially if there is no roof construction, high elements can be placed in the robot cell without taking up an exceptionally large amount of space. It is possible that as a result of unfavourable input/output of elements such as tools 11, product holders 12 and/or products 13 small gaps remain between the storage units 10 and their loads, between which gaps locations are produced that are too small to accommodate an element. In order to minimise this effect, it is possible, especially if all locations to be filled in the robot cell 1 are occupied, or if this is almost the case, to set up the processor 23 to re-rank the locations in the magazine section such that all combinations of storage unit 10 and load once again adjoin one another. In other words, the processor 23 can be set up to defragment the robot cell 1. As a result, by combining open spaces that in themselves are too small to accommodate a storage unit 10 including load, one or more new locations can again be created.
The above figures portray one embodiment of the automated robot cell according to the invention, where the robot cell is associated with one or more CNC processing machines. It must be understood that it is also possible to associate the robot cell 1 with other types of machine, the same sorts of measures as described above being needed. The above description describes only a number of possible embodiments of the present invention. It is easy to see that many alternative embodiments of the invention can be conceived, all of which fall under the scope of the invention. This is defined by the following claims.
Nieuwe elementen met gegevensdragers=New elements with data carriers
| Number | Date | Country | Kind |
|---|---|---|---|
| 1027332 | Oct 2004 | NL | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/NL05/50021 | 10/25/2005 | WO | 9/21/2007 |
