CN1748188A - Closed loop location detection system - Google Patents

Abstract

A closed loop location detection system for use in monitoring simultaneously the presence or absence of objects in at least two locations, comprises at least one detectable element per location and adapted to be associated with a respective object to be monitored, and at least one detecting device adapted to detect the detectable elements of the objects and so determine whether objects are present in, or absent form, all of the locations being monitored. Means are provided for causing an object to be fed to a location determined to be devoid of objects by the detecting device. Typically, the closed loop location detection system uses RFID technology, e.g. the detection device comprises at least one antenna and the detectable element comprising at least one RF tag. There may be provided one such antenna for each location to be monitored, whereby for a given location, a respective antenna detects the presence or absence of a respective tag thereby determining whether an object is present in this given location. Alternatively, the antenna can be adapted to monitor more than one location, wherein a position tag is associated with each location and means to deactivate the position tag are provided on each object, whereby when the object is fed to a given location, the means to deactivate that are provided on this given object, cause the position tag associated with the given location to stop being detected by the antenna thereby determining that a specific object has been fed to a specific location.

Description

Closed Loop Position Detection System

technical field

The present invention relates to automatic apparatus for handling objects and goods, and more particularly to the recognition of the arrival and departure of objects or goods at a location of such an automatic apparatus, such as an infeed area.

Background technique

Various equipment suppliers currently offer verification systems for their part placement systems. These systems are designed to verify that the correct part number is used in the proper feeder location to manufacture a given product. These verification systems are not fully closed-loop systems and require some level of human intervention, which can be a source of potential error. Moreover, these systems are usually specific to a certain model of machine and cannot be used on machines from other equipment suppliers. Also, these systems only authenticate feeders whose parts are in reels and cannot handle parts in other containers, nor other raw materials and tools.

In PCT Publication No. WO 01/82009, published on November 1, 2001 in the name of Cogiscan Corporation, an assembly line verification system is disclosed which verifies that the proper parts are being used on the placement machine correctly It also provides a means to verify that the proper tools, chemicals, and procedures are being used on each machine on the assembly line. The system operates in an open loop. PCT Publication No. WO 01/82009 is consistent with U.S. Patent Application Publication No. US 2003/0102367-A1, published June 5, 2003 in the name of Monette et al., which is hereby incorporated.

Contents of the invention

It is therefore an object of the present invention to provide a closed loop position detection system for identifying the arrival and departure of an object from an infeed area.

Thus, according to the present invention, there is provided a closed loop position detection system for simultaneously monitoring the presence or absence of an object at at least two positions, the system comprising at least one detectable element corresponding to each position and at least a detection device, said detectable elements can be associated with the respective monitored object, and said detection device can detect the detectable elements of the object and determine the object at all monitored locations does it exist.

Additionally, according to the present invention, a closed-loop method can be provided to simultaneously monitor the presence or absence of an object at at least two locations during the manufacturing process, the method comprising the following steps: (a) providing at each location at least one detectable element associated with the respective monitored object; (b) providing at least one detection device adapted to detect the detectable element of the object; and (c ) determining whether there is an object at each monitored position by using the information collected by the detecting device.

Furthermore, according to the present invention, a closed-loop method can be provided to simultaneously monitor the presence or absence of objects at least two positions during the manufacturing process, the method comprising the following steps: (a) providing each monitored object with a marker; (b) determining the presence or absence of the marker at each location; and (c) feeding at least one object at each location where no marker is detected in step (b) and a replacement object is required.

Furthermore, according to the present invention, it is possible to provide a closed-loop position detection system for simultaneously monitoring the presence or absence of a feeder at at least two positions in a manufacturing process, the system comprising at least one detectable element corresponding to each position , at least one detection device and a device; said detectable elements can be associated with respective monitored feeders; and said detection device can detect the detectable elements of the feeders, and Determining the presence of feeders at the monitored location, each of which contains parts, each of which is associated with a respective feeder; when a part is removed from the feeder, The device generates a signal to associate a new part located in the feeder with the feeder.

Description of drawings

Having thus generally described the features of the invention, there will now be a discussion of the accompanying drawings, which show by way of illustration a preferred embodiment in which:

Figure 1 is a schematic diagram of an assembly line component including a closed loop position detection system according to the present invention;

Figures 2 and 3 illustrate a second embodiment of the invention in which a locking mechanism incorporating a radio frequency antenna is used; wherein Figure 2 is a front view of a spool feed frame with no spools installed; and Figure 3 is a side view A view showing a reel holder of the reel holder in Figure 2, wherein the holder is equipped with a reel, and it is in the upper and lower positions;

Figures 4 and 5 illustrate a third embodiment of the invention, which is a variation of Figures 2 and 3, in which a locking mechanism incorporating a switching device is used; where Figure 4 is a front view of a reel feed stand , wherein no reel is installed; and Fig. 5 is a side view showing a reel support of the reel stand in Fig. 2, wherein the support is equipped with a reel, and it is in the upper and lower positions.

Detailed ways

The present invention is a continuation of the previously mentioned PCT publication WO 01/82009 patent for an assembly line verification system, which provides a closed-loop solution to the verification process. This solution includes some advantageous unique features which form a part of the present invention.

Although the invention was first applied in the verification of part placement machines, the invention has many other applications, some of which are discussed below as examples.

The system of the present invention uses automatic means to recognize the arrival and departure of objects eg from an infeed area. The feed area may contain multiple locations and, using the present invention, it is possible to identify which location is being used.

In the system of the present invention, the use of radio frequency identification technology is particularly attractive and effective. In fact, RFID technology offers a great way to eliminate human intervention, for example in the process of replacing an empty feeder with a feeder with parts.

The invention can also be used in other applications, for example, for any other equipment having at least one feed opening, for any movable part of equipment - such as a feed bank, or for any raw material, tool or Storage area for chemicals.

More specifically, a typical parts placement machine includes one or more infeed zones. Depending on the machinery supplier at each location, there can be multiple feeders per infeed zone. Each feeder typically holds a part tape and reel, a reel or reels of parts, or a tube or tubes of parts. Although the system described below is directed to a parts placement machine with a feeder containing parts packaged in tape and reel, it will be readily understood that the same system could be used to handle A component contained in a disc or tube.

In a system according to the invention (FIG. 1), each feeder will be identified by a radio frequency tag. The feeder markers are mounted on an arm which is permanently or temporarily attached to the feeder. The feed arm is also incorporated with a device to disable one or more position markers. When the reel is placed in a feeder, part information (part number, lot number, supplier, etc.) is associated with the feeder tag. This can be done, for example, by manual keyboard entry, by reading information in the form of bar codes, or by reading markings on component tapes and reels.

Depending on the configuration of the machine, one or more antennas are arranged near the infeed area. For each possible infeed location portion of the infeed area monitored by a given antenna, the antenna incorporates at least one radio frequency tag. The feeding arm is positioned on the feeder in such a way that when a feeder is added to the part placement machine, the corresponding antenna detects the arrival of the feeder mark and disables the position mark ( For example, the infeed arm shields the position marker from being detected by the antenna, thereby indicating that the infeed position in the part placement machine now contains a feeder, said infeed position being associated with the position marker ). By correlating the previously detected feeder marks with the position marks which are now no longer detectable by the antenna, it can be determined that a particular feeder has reached a given position in the machine.

Likewise, when a feeder is removed from the part placement machine, the antenna detects that the feeder marker has left and that the position marker is in the position released by the removed feeder. Through the correlation between the two events, the system can then identify the feeder that has been removed and determine the position that said feeder occupies on the part placement machine.

Another way to use RFID to achieve the same goal is to use multiple antennas, one at each detection location. In this case, each feeder or each probe object is identified by a radio frequency tag. An antenna is installed at each position in the feed area. These antennas will detect the presence of feeder marks and identify said feeder marks when an object is placed in the infeed area. These antennas will also detect that the feeder markers are not there when the objects move away. The antennas can be read individually or together by one or more reading devices. In feed trays and reels such as pick-and-place machines, there is an antenna at each feed position to detect feeder marks. For the infeed pans, there is either an antenna at each pan position that detects the pan markings, or an antenna in the infeed area that reads the markings of the infeed pans being used.

In some cases, it is not practical to place marks on the objects that are going to be placed on the machine. So a locking mechanism is installed on the machine, which needs to be unlocked before loading new objects and locked after loading, then these objects can be detected during loading and unloading. When locked back into place, the locking mechanism will change the state of a switchgear or detect a flag. This triggers an event: a new object entering the device must be recognized.

An example of the use of such a locking device is the feed reel of a Siemens pick and place machine. Said spools are provided on the feed bank and can be accessed at any time to replace any given spool with a new one while the feeder remains on the feed bank. In this example, one wishes to verify that the feeder is being used with the correct part for a given product being assembled. One way to solve this problem is to mark the feeder and read its identification mark when the locking mechanism returns to its locked position. The operator is then prompted to read the barcode label on the spool, and computer software establishes the link between the spool, the feeder and the machine program being used. This configuration is shown in FIGS. 2 and 3 .

Another way to achieve the same goal is to incorporate a switching device in the locking mechanism. This switching device will be the trigger that prompts the operator to read the new reel identification mark. Feeders can be identified by a marking and one of the methods discussed previously. This alternative configuration is shown in FIGS. 4 and 5 .

A software algorithm enables the system to verify that all feeders with the correct part and lot numbers are in the proper infeed positions in the part placement machine as required by a specific product proposal. This verification can be done during the operation of a product change, or during normal production where the feeder needs newer parts. This association between a given tool or material and a given location can also be used in many other contexts, such as warehouse location, physical location, etc.

To illustrate the application of the invention in another context, the invention is described in the context of a screen printing machine for electronics assembly. Before the components are mounted on the printed circuit board (PCB), a screen printer is used to deposit solder paste on the printed circuit board. For this purpose, they are equipped with solder paste injectors, stencils and some other tools such as blades and PCB holders. These components may be specific to a given PCB part number or a family of part numbers. They can all be identified with radio frequency tags and, with the invention described above, their identification can be obtained as they enter the machine. This allows software solutions to track and control those elements, such as verifying recipes and collecting traceable information.

Thus, the present invention provides a fully closed loop position monitoring system which, if desired, can also be provided with a verification feature which is independent of operator intervention (in most cases without manual scan). The system is not specific to a specific machine or equipment supplier, so it can be easily used for different types of processes in different industries. While enabling automatic control, it also provides real-time positioning of materials and tools.

Claims (47)

1. A closed loop position detection system for simultaneously monitoring the presence or absence of an object at at least two locations in a manufacturing process, said system comprising at least one detectable element and at least one detection device, at each of said locations All have the detectable elements on them, and the detectable elements are associated with the corresponding monitored objects, and the detection equipment can detect the detectable elements on the objects, thereby determining the The presence or absence of said object at the location. 2. A closed loop position detection system as claimed in claim 1, wherein means are provided for feeding an object to a position determined by said detection means to be free of objects. 3. The closed-loop position detection system as claimed in claims 1 and 2, wherein said closed-loop position detection system uses radio frequency identification technology, said detection device comprises at least one antenna, and said detectable element comprises at least one radio frequency tag. 4. A closed loop position detection system as claimed in claim 3, wherein one said antenna is provided for each monitored position, whereby each corresponding antenna detects the presence or absence of a corresponding marker for a given position , so as to determine whether there is an object in the given position. 5. The closed-loop position detection system of claim 3, wherein said antenna is adapted to monitor a plurality of locations, each location having a location marker associated therewith, and each object is equipped with said means for disabling position markings whereby, when an object is advanced to a given position, said means for disabling position markings provided on each of said given objects causes said and said The position marker associated with the given position is no longer detected by the antenna, thereby determining that a specific object has been advanced to a specific position. 6. A closed loop position detection system as claimed in any one of claims 1 to 5, wherein verification means are provided to ensure that only intended objects are fed to a given position. 7. A closed loop position detection system as claimed in any one of claims 1 to 5 wherein verification means are provided to determine if an inappropriate object has been fed into a position. 8. A closed loop position detection system as claimed in any one of claims 3 to 5 wherein verification means is provided to perform at least one of the following two functions: determine if an inappropriate object has been fed into a position And make sure the object is in a position as expected. 9. A closed loop position detection system as claimed in claim 8, wherein said radio frequency tag contains information about its associated object, said verification means being adapted to read said information to identify a position with an incorrect object. 10. A closed-loop method for simultaneously monitoring the presence or absence of an object at at least two locations during a manufacturing process comprising the following three steps: (a) providing at each location at least one detectable element associated with a respective monitored object; (b) providing at least one detection device adapted to detect a detectable element of said object; and (c) determining the presence or absence of said object at each monitored location through information collected by said detection device. 11. The closed loop method of claim 10, wherein after step (c), at least one object is fed in each location for which no object has been determined in step (c). 12. A closed loop method as claimed in claims 10 and 11, wherein said detection device comprises at least one antenna and said detectable element comprises at least one radio frequency tag. 13. The closed-loop method of claim 12, wherein each monitored location is equipped with one said antenna, whereby for a given location, a corresponding antenna detects the presence or absence of a corresponding marker to determine an object exists at the given location as described. 14. The closed loop method of claim 12, wherein said antenna is adapted to monitor a plurality of locations, each location having a location marker associated therewith, and the means for disabling said location marker is associated with each location Each object is associated, whereby when an object is fed to a given position, said means for disabling position marking associated with said given object causes a The position marker is no longer detected by the antenna, thereby determining that a specific object has been advanced to a specific position. 15. A closed loop method as claimed in any one of claims 10 to 14, wherein verification means are provided to ensure that only intended objects are fed into the designated positions. 16. A closed loop method as claimed in any one of claims 10 to 14, wherein verification means are provided to determine if an incorrect object has been fed to a position in step (c). 17. The closed-loop method according to any one of claims 12 to 14, wherein a verification device is provided to at least complete one of the following two functions in step (c): determine whether an incorrect object is entered Objects given a position and guaranteed to be in a position are expected. 18. The closed-loop method of claim 17, wherein said radio frequency tag contains information about its associated object, said verification device being adapted to read said information in order to identify an object with an incorrect value in step (c) s position. 19. A closed-loop method for simultaneously monitoring the presence or absence of an object at at least two locations in a manufacturing process comprising the steps of: (a) provide markings for each monitored object; (b) determining the presence or absence of markings at each location; and (c) feeding at least one object to each location where no marker was detected in step (b) and a replacement object is required. 20. The closed loop method of claim 19, wherein the marker in step (a) is attached to an object. 21. The closed loop method of claim 19, wherein said object comprises a feeder. 22. The closed loop method of claim 21, wherein said feeder comprises at least one of: (1) tape and reel; (2) disc; and (3) tube. 23. A computer program product comprising program code for carrying out the method as claimed in claims 10 to 22. 24. A data signal implemented as a carrier wave which, when loaded into a computer, provides the method as claimed in claims 10 to 22. 25. A closed loop position detection system for simultaneously monitoring the presence or absence of a feeder at at least two locations in a manufacturing process, the system comprising at least one detectable element at each location, at least one detection device, and a device; said detectable element can be associated with a corresponding monitored feeder; and said detecting device can detect the detectable element of the feeder and determine the feeder at all monitored positions presence or absence, each of said feeders containing parts, each said part being associated with a respective feeder; upon removal of a part from a feeder, said means generates a signal whereby Associates a new part located in this feeder with this feeder. 26. The closed loop position detection system of claim 25, wherein a means is provided for feeding a feeder into a position, said detection device determining that there is no feed in said position device. 27. A closed loop position detection system as claimed in claims 25 and 2, wherein said closed loop position detection system uses radio frequency identification technology, said detection device comprises at least one antenna and said detectable element comprises at least one radio frequency tag . 28. A closed loop position detection system as claimed in claim 27, wherein one said antenna is provided for each monitored position, whereby each antenna detects the presence or absence of a corresponding marker for a given position , so as to determine whether an object exists at the given location. 29. The closed loop position detection system of claim 27, wherein said antenna is adapted to monitor a plurality of locations, each location having a location marker associated therewith, and means for disabling said location marker Associated with each object whereby, when an object is fed to a given position, said means for disabling position markings provided on said given feeder is such that said given The position marker associated with the given position is no longer detected by the antenna, thereby determining that a specific object has been advanced to a specific position. 30. A closed loop position detection system as claimed in any one of claims 25 to 29 wherein verification means are provided to ensure that only intended feeders are fed to designated positions. 31. A closed loop position detection system as claimed in any one of claims 25 to 29 wherein verification means are provided to determine if an incorrect feeder has been delivered to a position. 32. A closed loop position detection system as claimed in any one of claims 27 to 29, wherein verification means are provided to at least one of the following functions: determine whether an incorrect feeder is sent to a position and Make sure the feeder is in one position as expected. 33. The closed loop position detection system of claim 32, wherein said radio frequency tag includes information about a feeder associated therewith, said verification means being adapted to read said information in order to identify a feeder having an incorrect location of the device. 34. A closed loop position detection system as claimed in any one of claims 25 to 33, wherein said means for generating a signal comprises a switching device, said switch being actuated when a part is removed from the feeder equipment. 35. The closed loop position detection system of claim 34, wherein said switching device, when activated, indicates that the feeder is not there. 36. The closed loop position detection system of claim 34, wherein said switch device is independent of said detection device when activated. 37. A closed loop method as claimed in any one of claims 10 to 18, wherein said objects are feeders, each feeder comprising a plurality of components, each component being associated with a respective feeder , a means is provided to generate a signal when a part moves away from the feeder so that a new part placed on the feeder is associated with the feeder. 38. The closed loop method of claim 37, wherein said means for generating a signal comprises a switching device which is activated when a part is removed from the feeder. 39. The closed loop method of claim 38, wherein said switching device, when activated, indicates that the feeder is not there. 40. The closed loop method of claim 38, wherein the switching device is independent of the detecting device when activated. 41. The closed-loop method of any one of claims 19 and 20, wherein said objects are feeders, each feeder comprising a plurality of components, each component being associated with a respective feeder, Means are provided to generate a signal when a part moves away from the feeder, thereby causing a new part placed on the feeder to be associated with the feeder. 42. The closed loop method of claim 41, wherein said means for generating a signal comprises a switching device which is activated when a part is removed from the feeder. 43. The closed loop method of claim 42, wherein said switching device, when activated, indicates that the feeder is not there. 44. The closed loop method of claim 42, wherein the switching device is independent of the detecting device when activated. 45. A closed loop method as claimed in any one of claims 41 to 44, wherein said feeder comprises at least one of: (1) tape and reel; (2) disc; and (3) tube . 46. A computer program product comprising program code for carrying out the method as claimed in claims 37 to 45. 47. A data signal embodied in the form of a carrier wave which, when loaded into a computer, provides the method of claims 37 to 45.

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