Patent Application
20070052541
This application claims priority of German application No. 102005042532.1 filed Sep. 07, 2005, which is incorporated by reference herein in its entirety.
The invention relates to a system for detecting a local utilization state of a technical system for transporting and/or packaging objects, with the objects having a device for identification, especially an RFID tag, the device for identification having a data memory, the system having at least one read-write unit for the contactless reading of at least one data memory of an object. The invention also relates to a read-write unit in accordance with the preamble of and independent claim, and a method in accordance with the preamble of another independent claim.
Such a system, read-write unit or method is used with automated systems, product or delivery systems, or packaging lines or similar technical systems. To guarantee smooth production or packaging using complex automation and production facilities, various systems are known for the detection of utilization states, such as a congestion or shortage of products or objects. The aim of these systems is to avoid the idle time or downtime that occurs due to congestion or shortages of products, or of the objects to be transported. The technical cost and the manpower costs for detecting and rectifying the disturbances caused by the utilization states is generally very high, and the utilization states usually have the effect of impeding production. Generally, various types of sensors can be used to monitor the utilization states. These are, for example, sensors that operate on an optical or radio basis and can be universally used. Sensors that operate on an optical basis are, for example, realized by bar code scanners.
Radio-based sensors, for example, use RFID technology (radio frequency identification). Widespread use is also made of optical sensors as light barriers that usually do not require a label in the sense of the RFID tag.
RFID is a very reliable technology that is able to track objects that are largely static or moving, but in the past the high cost and inefficient process control made RFID uneconomical. RFID tags or read-write units can now be inexpensively manufactured. By means of RFID it is possible to guarantee that electronic labels can be read even under production or packaging conditions that are sometimes poor. Furthermore, it is not necessary to have an optical link to the object. It is very easily possible to shield the object if necessary and still read the RFID tag. This is a clear advantage of the RFID technology compared with optical reading methods, because in this way it is also possible to process objects that do not permit labeling in the conventional sense, or where environmental conditions do not permit labeling on the outer cover of the transported object.
Systems for detecting the utilization state of technical systems usually have a visualization of the existing circuit diagram that provides a general view of the complete system. With the increasing automation and complexity of such production lines, packaging systems or technical systems in general, the number of RFID tags to be read by the read-write unit also increases.
Frequently in the past, the machines had a technical system or a line where they are activated only be means of light barriers, i.e. the machine started if a light barrier detected an object in front of the machine. Where there are long pauses between products, for example due to a shortage, the machine continually stops and starts to process the incoming object. The same applies to the situation downstream of the machine. If the light barrier there does not signal the removal of the processed object at a certain distance from the machine within a specific time, the machine stops to prevent congestion. A superimposed operating data detection system, however, signals only the actual disturbance to the machine but not the congestion or shortage that had most probably caused it. What is worse, however, is that this causes an unwanted stop and go operation because the congestion or shortage was not detected in time and therefore an appropriate reaction was not possible. A stop and go behavior is absolutely to be avoided from the point of view of smooth production. At present it is still very difficult to reliably detect a congestion or shortage in time using simple inexpensive means.
An RFID process control system is known from US 2005 0080680 A1, that combines various components in a single unit for use in tracking systems that function with inventory objects fitted with RFID tags. The system combines an RFID controller and reader unit, process software, a computer-controlled switch and a supply management system in a single unit, with an RFID process control being realizable in conjunction with a wide spectrum of inventory tracking applications.
The object of the invention is to monitor a technical system, or objects transported in the technical system, and identify utilization states in time.
This object is achieved by means of a system of the type named in the introduction in that the system by repeated reading of the data memory of at least one object a local utilization state of the technical system can be analyzed [sic]. This object is further achieved by a read-write unit and a method for detecting a local utilization state by means of the features named in certain independent claims.
Read-write units are mounted at different positions along the transport path of the objects within the technical system to optimize the use of the existing devices for identification, especially RFID tags, of the objects for detection of congestion or shortages. For this purpose, a read-write device cyclically performs a “bulk reading”. Bulk reading is the reading of several devices for identification in one read operation. If the number of identification devices detected is above a certain limit, a congestion message is output. If on the other hand the number is below a certain limit, a shortage message is output. In addition or as an alternative, a check can be carried out at each reading operation to determine whether the identities or labels of the devices read for identification are the same as in the previous read operation, or whether a high overlap is present. If this is the case, it means that the products are stationery on the conveyor and congestion must therefore have occurred or be imminent, because the rate of change is too low. In this case, also, a congestion message or warning can also be output. A shortage, or imminent shortage, is also detected by a low number of objects over a specific time period and is also reported as a shortage message or shortage warning.
Furthermore, two read-write units can be used to identify the same object at different times at various positions within the technical system using various readings taken at staggered times, to thus determine the time taken to travel the path between the two read-write units. In this respect, it is useful to use a data processing unit that processes the status data of both read-write units and enables a comprehensive analysis of the technical system. By means of the detailed information or the diagnostic data generated by the data processing unit, it is possible to appropriately optimize the traffic on the conveyor for the analysis and resolution of undesirable utilization states.
In addition to system fault and production states (machine or line produces without faults), utilization states such as congestion warning or shortage warning can be entered in a production data acquisition system. This enables a more efficient monitoring of the production, manufacturing or packaging machine line using simple means of utilizing the devices used for other purposes (product tracking or logistics support) for identification (RFID tags). Thus this provides the basis for appropriate automatic optimization for the avoidance or resolution of congestion and increasing the efficiency of production, manufacturing or packaging machines.
An advantageous form of embodiment of the system for the detection of a local utilization state of a technical system for the transport and/or packaging of objects is a system that includes a first read-write unit for initial reading of the data memory of at least one object and at least a second read-write unit for a repeat reading of the data memory. By this means, the tracking of an object within the technical system or along the transportation path of the object is guaranteed, during which process additional data on the transportation duration between the read-write units can be obtained.
In a further advantageous embodiment, the first read-write unit and the second read-write unit are provided at various positions on the transportation path of the object for reading the data memory of the object. Using the transportation between the first read-write unit and the second read-write unit, it is possible to detect a congestion or shortage.
In a further advantageous embodiment, a first local utilization state is a local congestion and a second local utilization state is a local shortage in the transportation of the objects, whereby other utilization states can be defined as a function of the technical conditions or other circumstances.
Furthermore, it is advantageous if the write-read unit is provided for simultaneously reading data memories of objects that are in the detection area of the particular read-write unit, in order to determine how many, and which, objects are in the detection area. In this way, a congestion or shortage can be determined locally at a read-write unit by the repeated reading of the data memories of the objects. A repeated detection of the same objects means in this case a congestion. If too few objects are detected this indicates a shortage.
Advantageously, a data processing unit is used to display and/or process the status data of the read-write unit. The display of the status data of the read-write unit, or of the read-write units, can usefully be used for the manual rectification of the utilization state. Furthermore, the processing by the data processing unit affords the opportunity of further using the status data for automatic rectification.
The generation of diagnostic data by the data processing unit for the control of the technical system is also advantageous, with a feedback from the system for detection of a local utilization state being used as a diagnostic system and for control units. Therefore, it is possible to achieve the best possible control of the production or packaging line or technical system as a function of the utilization state and to optimize the utilization state.
In a further advantageous form of embodiment, the system provides for detection of a utilization state of the complete technical system or part areas of the technical system. In this way, it is possible to deal with several problem zones on the transportation path at the same time using an overall concept. In particular, it is possible to avoid a stop-go behavior, which is very obstructive with regard to optimum operation.
In a further advantageous embodiment, the read-write unit provides for the storage of status data and/or diagnostic data of the data processing unit on the data memory of at least one object. This feature is shown to be advantageous if the properties of the object are relevant for the duration required by the object to be transported through the technical system or parts thereof. For example, in a paint shop an object can be painted within the technical system and be dried during the onward transportation. Before the next step can be carried out within the process, the object must be dry. If the paint is still wet, the quality of the object would be impaired. By detecting the object at two different points within the transportation path using two different read-write units, it is possible to determine the duration of the drying period. In this way, a decision can be made as to whether the object is suitable for the next processing step.
This type of process time monitoring can also be used in other applications. For example, the monitoring or detection of a time overshoot is important in the pharmaceutical or foodstuffs area because certain products may remain in a certain processing state for only a specific time period.
Advantageously, the system could include a write-read unit designed as a control unit, with the control unit also having a data processing unit in addition to the read-write unit, in order to realize a mobile system. This mobile system can be flexibly used within any technical system and especially can be used for a quite specific problem, i.e. a quite specific position can be chosen for use of this system within the transportation path.
Further advantageous embodiments and preferred developments of the invention are given in the description of the illustrations and/or in the subclaims.
The invention is described in more detail in the following with the aid of exemplary embodiments shown in the illustrations. These are as follows:
A through-time tracking is then particularly useful if a fault within a machine 14 or a transport section cannot be directly detected or analyzed. For example, this is the case if a machine 14 is not designed to signal a utilization state, a disturbance or a fault. It is frequently the case that the machine 14 has no diagnostic capability or is not designed to record measured values in order to determine a utilization state. The machine 14 could not also be interlinked and is thus not message-capable. If on the other hand there is a through-time tracking on the transportation path at which the machine 14 is installed, the conveyor system elements 12 and/or the machine 14 are monitored by the through-time tracking.
It is furthermore possible to simultaneously analyze and eliminate several local utilization states along the transportation path within the technical system 2.
By suitable positioning of the read-write units, the early identification of important information on the utilization state is likewise possible and this information can be immediately used for the manual or automatic rectification of the utilization state. Furthermore, constant optimization at high transport speed of the object can be used to obtain the desired utilization state without object densities that impede the process.
To sum up, the invention relates to a system for the detection of a local utilization state of a technical system for the transportation and/or packaging of objects, with the objects having a device for identification, especially an RFID tag, the device for identification having a data memory and the system having at least one read-write unit for the contactless reading of at least one data memory of an object. The system facilitates an early signaling of a utilization state of the technical system, such as a congestion or shortage of objects, using the devices for identification, that can also be used for object tracking. The detection of the local utilization state is realized by the repeated reading of the data memory of at least one object.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102005042532.1 | Sep 2005 | DE | national |
