WO2005017633A2

WO2005017633A2 - Configurable part identification system

Info

Publication number: WO2005017633A2
Application number: PCT/US2004/025039
Authority: WO
Inventors: Jeffrey A. Perkins; Vincent L. Bednarz; Stephen G. Nemethy
Original assignee: Nordson Corp
Current assignee: Nordson Corp
Priority date: 2003-08-04
Filing date: 2004-08-03
Publication date: 2005-02-24
Anticipated expiration: 2006-02-04
Also published as: WO2005017633A3

Abstract

Object identification apparatus and method are provided in which one or more features of an object are detected and linked with an object identifier. Features of the object itself are used to identify the object. A configurable identification system is provided by which a user can relate a sensor output to an object identifier without having to program or re-program software or firmware. In one embodiment, sensors used as control devices are also used as the identification sensors.

Description

CONFIGURABLE PART IDENTIFICATION SYSTEM

Related Applications

[0001] This application claims the benefit of pending United States provisional patent application serial no. 60/481,174 filed on August 4, 2003, for INTEGRATED PART ID METHOD, the entire disclosure of which is fully incorporated herein by reference.

Technical Field of the Invention

[0002] The invention relates generally to identifying parts or objects that are to have a process applied to them. More particularly, the invention relates to apparatus and methods for identifying a part or object by detecting a feature thereof. The invention also relates to a configurable identification system for associating a detected feature with identification data.

Background of the Invention

[0003] Material application systems are used to apply one or more materials in one or more layers to an object. General examples are powder coating systems, liquid spraying systems such as for applying conformal coatings to printed circuit boards or adhesives to surfaces, and liquid paint spraying systems. These are but a few examples of a wide and numerous variety of systems used to apply materials to an object. Such systems typically include a number of process parameters that are controlled as part of a material application process. These process steps and parameters may include but are not in any manner limited to pressure, air flow, electrostatic parameters such as voltage and current, spray patterns, temperature parameters, material flow rates, object conveyance control, timing controls and so on.

[0004] Because of the wide variety of processes that can be applied to an object, it is usually necessary to identify an object as it passes down a conveyor line prior to initiating the process. Process parameters may be adjusted or selected depending on the object being sprayed.

[0005] In known part identification systems, a flag or other identification device usually travels with a part or group of parts that are going to be processed the same way. These flags are coded or configured in such a way that an optical sensor can detect unique features of the flag and therefore identify the objects associated therewith. Once identified, the material application control system can adjust, set or select the process parameters for that object or group of objects associated with the flag. The flags are separate devices from the objects themselves to which a process is going to be applied.

[0006] In addition to having to carry an inventory of identification flags, a user must have a control function that is programmed to detect and interpret the flag information. In known systems, these control functions are pre-programmed either through software, hardware, firmware or combinations thereof so that the flags can be detected and then the appropriate process parameters set. This process control architecture thus necessitates having to have a software programmer re-program the control logic every time a different part is going to be processed that is not already programmed. Such programming efforts are expensive and require system shutdown in order to upload or otherwise modify the system software to recognize the different part.

Summary of the Invention

[0007] The invention provides apparatus and methods for identifying parts or objects by detecting a feature of the object. In one embodiment, optical sensors are used to detect object features when the object passes in front of the sensors at a known time or position. By detecting unique features of the object itself, the object can be identified by accessing a look-up table or other database or data file that stores one or more relationships between possible sensor outputs and object identification data. Object identification data can be generally referred to as an identifier herein since the actual form and content of the data is a matter of design choice, hi one embodiment, a look-up table is stored that relates various sensor output signals to corresponding identifiers or identification data. The identification data may be in any suitable form and may convey a wide variety of information, from as simple as an object identification number to data that indicates various process parameters to be applied to the identified object.

[0008] By detecting unique features of the actual object that is being processed, there is no need for a separate inventory of identification flags nor the need to have an identification flag accompany a group of objects along an object transport such as for example a conveyor system.

[0009] In accordance with another aspect of the invention, an object identification apparatus is provided that is configurable without having to re-write or otherwise modify software or firmware code, hi one embodiment, such apparatus is configurable by the end user through the use of a convenient graphical user interface (GUI) or other user interface, thereby avoiding any need for software programming. In an exemplary embodiment, a user is provided with a configuration illustration and provides an object identifier or object identification data that is stored in relationship to corresponding sensor outputs from a sensor that detected an object feature. This aspect of the invention may be used in combination with detecting a feature of the actual object being processed, or alternatively may be implemented with the use of identification flags or other devices that are not integrally part of the actual objects being processed. Alternatively, the configuration process may involve manual input of the expected sensor output, rather than using the actual sensor output signals, during configuration.

[0010] In accordance with another aspect of the invention, a material application system is provided with an apparatus for identifying objects that are to be processed, the identification apparatus including a sensor that detects one or more features of the object and produces an output that corresponds to the detected features. A configuration illustration is presented to the user, and the user is provided a device for inputting an object identifier or identification data. Configuration logic receives the sensor output and the identification data and stores the relationship therebetween. In such manner, sensor output signals can thereafter be used to identify the detected object. Once the object is identified, the system can apply a desired process to the object. In an exemplary embodiment, the material application system comprises a powder coating system.

[0011] In accordance with another aspect of the invention, one or more sensor arrangements that are used to detect the one or more features of objects being processed are also used to provide a control signal used in the applied process. In one embodiment, a sensor output is used as a timing signal to start or trigger a material application device such as a spray gun or dispensing gun for example. This allows a single sensor arrangement to both identify the objects and to help control the process applied to the objects, thereby avoiding the need for multiple sensors arrangements.

[0012] The invention further contemplates the use of such identification apparatus in a material application system. Moreover, the invention contemplates the methods embodied in the use of such identification apparatus, as well as in another embodiment of the invention a method for configuring a material application system, comprising the steps of detecting a unique feature of an object that is to be processed; producing a signal that corresponds to the detected feature; and storing a relationship between the signal and an object identifier or identification signal. In an exemplary embodiment the user is provided a device for inputting object identification signal or data so that the user can configure an identification system by storing a relationship between the signal that corresponds to the detected feature and an object identification signal. The configuration logic can be made user friendly by providing a configuration illustration to the user, such as for example a look-up table via a graphical user interface. This configuration process is realized without the need for writing or modifying software or firmware code. In yet another embodiment of the invention, the method for configuring a material application system includes the step of producing a process control signal.

[0013] These and other aspects and advantages of the present invention will be apparent to those skilled in the art from the following description of the preferred embodiments in view of the accompanying drawings.

Brief Description of the Drawings

[0014] Fig. 1 is a simplified schematic diagram of a material application system with an embodiment of the invention used therein;

[0015] Fig. 2 is a simplified representation of how an object can be identified in accordance with one aspect of the invention;

[0016] Fig. 3 is an example of a visual representation presented to a user for configuring an identification system in accordance with another aspect of the invention; and

[0017] Fig. 4 is an exemplary flow chart for a configuration routine in accordance with an aspect of the invention.

Detailed Description of the Invention and Exemplary Embodiments Thereof

[0018] The invention contemplates a number of aspects for object or part identification including but not limited to: identifying an object by detecting a feature or features of the object itself; providing a user configurable identification system without the need for writing or modifying software or firmware; and using a sensor for both producing an object identification output and a process control output. The invention is well suited for use in a material application system although the invention will find use in other applications. The words 'object' and 'parts' are used interchangeably herein to refer to any workpiece to which a process is to be applied based in part as a function of identifying the workpiece prior to application of the process. There is no particular limitation to the invention as to the type of process applied or the methods and apparatus used to apply such processes. [0019] With reference to Fig. 1, in an exemplary embodiment, the present invention is illustrated being used with a material application system, such as, for example, a typical powder coating spray apparatus 10. Such an arrangement commonly includes a powder spray booth 12 in which an object or part P is to be sprayed with a powder coating material. The application of powder to the part P is generally referred to herein as a powder spraying or coating operation, however, there may be any number of control functions, steps and parameters that are controlled and executed before, during and after powder is actually applied to the part.

[0020] As is known, the part P is suspended from an overhead conveyor 14 using hangers 16 or any other conveniently suitable arrangements. The booth 12 includes one or more openings 18 through which one or more spray guns 20 may be used to apply coating material to the part P as it travels through the booth 12. The selected design and operation of the material application system 10, including the spray booth 12, guns 20 and the conveyor 14, form no part of the present invention and may be selected based on the requirements of a particular coating application. The control system 22 likewise may be a conventional control system such as a programmable processor based system or other suitable control circuit. The present invention may be realized with control logic that may be integrated into the basic control system 22 or can be provided as a separate control function. The exemplary embodiments described herein include logic that is incorporated into the basic control system 22 for the material application system. The control system 22 need only be programmed to recognize and interpret the sensor signals and to present and store a configuration routine for object identification so as to then generate appropriate process control functions for the process being applied to the identified objects.

[0021] While the described embodiments herein are presented in the context of a powder coating system, those skilled in the art will readily appreciate that the present invention may be used in any liquid, solid particulate or other material application system. The specific design and operation of the material application system selected provides no limitation on the present invention except as otherwise expressly noted herein. The invention thus provides a convenient object identification apparatus and methods for identifying one or more characteristics or features of a part that will have material applied thereto. Thus, the invention may be used in a wide variety of different ways, including to identify an associated group of parts, and in particular one or more characteristics of that group, for example a physical feature of the parts such that by having identified the part or group of parts, the control system then carries out a process to be applied to those parts. The process parameters that are associated with any particular group of identified parts can include a wide variety of information as to the process or can be as simple as indicating that large parts get one color and smaller parts another color, or optionally to identify one or more characteristics of the coating operation to be applied to an associated group of parts, such as for example the type of material applied or the spray technology (e.g. electrostatic, non-electrostatic, tribocharging, corona charging and so on to name a few examples), or still a further option to identify one or more characteristics of a group of parts and to also identify one or more characteristics of the coating operation to be used with that group of parts. The level of complexity of information that is associated with an identified part is determined by design of the desired level of control and sophistication of the material application system, and therefore may be as widely varied, simple or complex as is desired by the end user. An identification system in accordance with the present invention can thus accommodate many different levels of complexity and information coding, from the simplest form of part number encoding to highly complex parameters of the material application system, thus being limited only by the creativity and cost constraints imposed in the design of the overall material application system.

[0022] While various aspects of the invention are described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects may be realized in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Still further, various alternative embodiments as to the various aspects and features of the invention, such as alternative materials, structures, configurations, methods, devices, software, hardware, control logic and so on may be described herein, but such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the aspects, concepts or features of the invention into additional embodiments within the scope of the present invention even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the invention may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless so expressly stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present invention however, such values and ranges are not to be construed in a limiting sense and are only intended to be critical values if so expressly stated.

[0023] With continued reference to Fig. 1, typical automated material application systems use an optical detector or optical scanning to detect position and sometimes to detect movement of the parts P as they are conveyed through the spray booth 12. In the embodiment of Fig. 1, a pass through optical system 30 is illustrated. In this specific example, the optical system 30 is realized in the form of a through beam light curtain having a emitter array portion and a receiver array portion. Which side of the booth 12 has the receiver or emitter is optional, and some light curtain designs include emitters and receivers mounted in each array, thus allowing bidirectional light transmission.

[0024] The light curtain 30 is basically a longitudinal array of infrared emitters and receivers that the parts P pass between as they enter the spray booth 12. If light is detected then a feature of the object is not blocking the light, but if one or more of the receivers suddenly stops receiving light, presuming normal operation of the devices themselves, then the control system knows that a feature of the object has passed between the two arrays. Thus, the light curtain 30 is typically used to detect for example the leading and trailing edges of a part P. This information can be used, for example, to control coating spray gun on/off trigger times, trigger delay times, spray duration times and so on. A typical through beam light curtain is model SM31 available from Banner Engineering Corporation, Minneapolis, MN. Note that typically the parts P are suspended from the conveyor 14 so as to be positioned approximately in the middle of the longitudinally active region of the light curtain 30. It is also known to use reflective (as distinguished from through beam) optical systems in which an emitter and receiver are positioned on the same side of the booth. These arrangements may include a single emitter/receiver or an array of two or more such devices depending on the overall system requirements.

[0025] In accordance with a first embodiment of the present invention, the sensor arrangement 30 is used to identify objects as well as to optionally produce a control signal such as a timing signal or a position signal, both signals and so on. The control system 22 can use this control signal to further generate process control 38, timing and so on. The invention may be realized with two separate sensor arrangements, one for timing and the other for identification, but the preferred approach is to use one sensor arrangement to perform both functions. The number of individual detectors used in the sensor arrangement 30 is a matter of design choice and will be determined in large measure by how many different part configurations need to be uniquely identified.

[0026] As noted in Fig. 1, the sensor arrangement produces an output 32. This output 32 may be a single signal or a combination of signals depending on the particular type of sensor used, hi the exemplary embodiment herein, the sensor arrangement 30 comprises four separate optical devices. These four devices are arranged so as to detect features of an object that passes between them. An additional one or more sensors may be used to detect features from a different angle. For example, a detector may be positioned so that the object passes over the detector, so that such detector could be used to detect for example whether a wide or narrow object is being identified. The types and number of features of the objects being detected is only limited by the physical shape of the objects themselves, the number of uniquely detectable configurations there are of the objects and the selection of sensor arrangement chosen. Again, the overall level of simplicity or complexity of a specific embodiment of the invention is a matter of design choice.

[0027] The sensor output 32 is input to an identification logic 34 which for example may be a software routine executed by the control system 22. Circuits may be provided as needed to format or convert the sensor output 32 into a digital signal that is processed by the identification logic 34. The identification logic 34 may also be provided as a separate routine executed by as different control circuit. The sensor arrangement 30 along with the identification logic 34 thus provides one embodiment of an object identification system, which further may optionally include configuration logic, an input device and a display device.

[0028] Once the object has been identified, an identification signal or other suitable indication 36 is generated which the control system 22 uses to then implement the associated process controls 38. The process controls 38 are illustrated in broken line back to the material application system 10 because there is an almost infinite variety of ways, both known and later developed, that the control system 22 can control the material application system 10 once the object has been identified. Similarly, the sensor output 32 is shown coupled to the identification logic by a broken line because again the particular interface will be a function of the type of sensor selected and the design of the control system 22 and the identification logic 34.

[0029] Optionally associated with the identification logic 34, or useable as a separate stand alone feature of the invention, is a configuration logic 40. The configuration logic 40 may be for example a software routine that is executed by the control system 22, or by a separate control circuit that either alone or with the identification logic 34 executes the configuration routine. The configuration logic 40 is used to store a relationship between the detected object feature, as indicated by the sensor output 32, and object identification information or identifier 42 provided by a user such as, for example, by use of an input device 44. A display 46 may be used to provide a visual representation of the configuration routine and process to the user. [0030] As used herein the term "identifier" refers to any form of information or data that provides object identification in that the identifier is uniquely associated with a corresponding sensor output for a unique object feature or features. Thus the identifier can be any data in any form, be it a number, a letter, word, bits of data and so on.

[0031] The aspect of the invention relating to a configurable system is not a necessary feature in realizing benefits of the invention. The identification logic can be pre-programmed if so desired, whereby the invention is useful in providing an object identification process by which an object is identified by detecting a feature of the object itself. However, in many applications it will be advantageous to also implement the configurable aspect of the object identification process.

[0032] A typical example of a configuration logic 40 could be a simple database program such as Excel™ that can be used to create a look-up table that relates sensor outputs to a corresponding object identification input from the user. The type of database or data record stored is entirely a matter of design option. The data stored thus provides a way to identify objects after the configuration or set-up is completed because for each unique sensor output signal there will be an .associated data or signal stored that indicates to the control system 22 the object that has been identified.

[0033] A significant aspect of this embodiment is that the user can configure the identification system without having to write or modify any software or hardware. The user simply inputs an identifier 42 to the database to be associated with a particular sensor output 32. As another alternative, the user can also input the possible sensor outputs, rather than using the actual sensor outputs.

[0034] Figs. 2 and 3 provide a simple example of how the present invention can be used for object identification. In Fig. 2, four optical detectors 30a, 30b, 30c and 30d (also labeled 1, 2, 3 and 4 in the drawings) are used to detect features of the objects P, P' and P". In this example, the objects can be distinguished from one another by detecting the presence or absence and location of an opening 50 in the body 52 of the object. In accordance with the invention, the sensor outputs are sampled at the appropriate time so that the data collected is for that point in time that the sensors 30 are always looking at the same position on the object. The timing can be programmed so that the sensor outputs are deemed valid and stored during a pre-determined time interval or position of the object relative to the sensor 30. In the exemplary case, a detector will be 'on' if it detects light from its associated source and will be 'off if no light is detected. For the example of a pass through type sensor 30, for object P the sensor devices 30b, c and d will be on and device 30a will be off. For object P', the devices 30a and 30d are off and 30b and 30c will be on. For object P", all four devices will be off. As Fig. 3 illustrates, a simple table or matrix can be used to relate each valid sensor output 32 with an identifier 42. In the example of Fig. 3, the table indicates which sensor devices are on in order for the logic to determine the correct object identifier. During set-up, as each object passes in front of the sensor 30, the user can assign an identifier for each unique and valid sensor output by assigning a number to that combination. This can be done by the user simply entering appropriate information into the table. No software programming or re- programming is needed. Fig. 3 further illustrates that the sensor outputs can be logically AND'd and OR'd as desired. For example, there may be two classes of objects that share a common and unique feature that will undergo the same process. Thus, that common feature can be used in a logical OR function. For example, part identifier 1 is recognized if device 1 is off and all other devices are on (e.g. object P in Fig. 2). Identifier 2 is recognized if device 1 is off OR device 2 is off (thus parts P and P" would get the same process associated with identifier 2). Identifier 12 is recognized if all four detectors are off (part P" in Fig. 2) and identifier 7 is recognized if devices 1 and 4 are off or device 2 and 3 are off.

[0035] It will be recalled that each identifier is then used by the control system 22 to execute predetermined process controls to apply a process to the identified objects.

[0036] Fig. 4 is an exemplary flow chart for an identification configuration routine. At step 100 the sensor 30 output is sampled at the appropriate time, meaning that each object is "viewed" at its same physical position. If the output is not a potentially valid combination at step 120 a fault can be indicated at step 104. If the output is potentially valid then the user can review the configuration display at step 106, for example, the table of Fig. 3 can be presented on a video display (such as by using a conventional graphical user interface or GUI) so that the user can assign an identifier to the sensor output at step 108. This relationship between the sensor output and the identifier can be stored at step 110 and at step 112 the program either loops back to step 100 to configure additional objects or ends at step 114. After the identification system has been configured, the logic will identify objects automatically when their corresponding sensor output is detected.

[0037] It should be noted that the configuration routine could also be carried out manually in that the user could fill in the database table by visually determining which sensor devices will be on or off, however, more accuracy can be expected if the actual device outputs are used. [0038] The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon a reading and understanding of this specification and drawings. The invention is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

Claims:We claim:

1. Configurable identification apparatus for a material application system, comprising: a sensor, said sensor producing an output that is a function of a feature of an object that is to be processed; a display that presents a configuration illustration to a user; an input device by which the user selects identification data for the object; and configuration logic that receives said output and stores a relationship between said feature and said selected object identification data.

2. The apparatus of claim 1 wherein said sensor comprises a plurality of optical detectors in the form of an array, said array producing a plurality of output signals that uniquely represent a corresponding plurality of object features.

3. The apparatus of claim 2 wherein said detectors detect an object and produce a timing signal that is used to control a selected process.

4. The apparatus of claim 1 wherein said illustration comprises a table that relates different sensor outputs to selectable object identification data.

5. The apparatus of claim 1 wherein said object identification data corresponds to one or more parameters of a process to be applied to an object.

6. The apparatus of claim 1 in combination with a powder coating system, said objects being coated with powder coating material by a process that is a function of said object feature.

7. A method for configuring a material application system, comprising the steps of: detecting a unique feature of an object that is to be processed; producing a signal that corresponds to said detected feature; displaying a configuration illustration to a user; storing a relationship between said signal and an object identifier.

8. The method of claim 7 comprising the step of inputting an object identification signal as a function of said signal and a process to be applied to the object.

9. The method of claim 7 comprising the step of relating said object identification signal to a corresponding process to be applied to the object.

10. The method of claim 7 comprising the step of presenting a visual illustration to the user in the form of a table that relates each object identifier with a uniquely corresponding signal produced by detecting said unique feature.

11. An object identification apparatus for a material application system, comprising: a sensor, said sensor producing an identifier output that is a function of a feature of an object that is to be processed; said sensor producing a timing output that is a timing signal used to control a process applied to the object.

12. The apparatus of claim 11 wherein said sensor comprises a plurality of optical detectors in the form of an array, said array producing a plurality of said identifier output signals that uniquely represent a corresponding plurality of object features.

13. The apparatus of claim 11 wherein said timing signal is used as part of a trigger control for a material application device.

14. The apparatus of claim 11 comprising a display for presenting a configuration illustration to a user, an input device by which the user inputs one or more object identifiers, and configuration logic that receives said sensor identifier output and stores a relationship between said identifier output and said user input object identifier.

15. The apparatus of claim 11 wherein said identifier output and said timing output are derived from the same sensor signal.

16. A method for configuring a material application system, comprising the steps of: detecting a unique feature of an object that is to be processed; producing a signal that corresponds to said detected feature; storing a relationship between said signal and an object identification signal.

17. The method of claim 16 comprising the step of producing a process control signal with a device that also produces said signal that corresponds to said detected feature.

18. The method of claim 16 wherein said object identification signal is input by a user during a configuration process, said material application system during normal operation being able to identify objects based on said stored relationship.

19. Configurable identification apparatus for a material application system, comprising: a sensor, said sensor producing an output that is a function of a feature of an object that is to be processed; an input device by which the user assigns an identifier for the object; and configuration logic that receives said output and stores a relationship between said feature and said identifier.

20. The apparatus of claim 19 wherein said material application system comprises a control system that during normal operation of the material application system uses said stored relationship to identify objects.

21. The apparatus of claim 20 wherein said control system also uses said sensor output as a timing signal.

22. Object identification apparatus for a material application system, comprising: a sensor, said sensor producing an output that is a function of a feature of an object that is to be processed; identification logic that relates said sensor output to stored data of one or more object identifiers that are each uniquely associated with one or more valid sensor outputs so that said identification logic can identify the object.