Storage rack with automatic storage location booking

Abstract

Storage rack (10) with a plurality of superimposed support columns (14) for supporting storage carriers (15) which can be conveyed by means of an automatic loading and unloading device (13), with at least one access opening (18) for feeding and unloading the storage carriers (15), with a computer (20) in which information about stored goods (17, 17a) is stored, wherein at least one image acquisition device (24) is provided which is suitable for the complete optical acquisition of the storage carrier (15) and for the optical acquisition of the stored goods (17, 17a) placed in the storage carriers (15) and generates digital image information therefrom, wherein the digital image information is stored in the computer (20) and can be retrieved by means of a display device (22, 23), wherein a selection device is associated with the display device (22).a storage carrier (15) can be selected based on the digital image information and moved into the access opening (18) by means of the computer (20), characterized in that the computer (20) has an image data archive memory (34) for archiving the digital image information of the storage carriers (15) and an image data processing device (38) which is designed to detect changes in the loading situation of storage carriers (15) and to detect free storage spaces by comparing the digital image information from the image data archive memory (34), and in that the image data processing device (38) divides the digital image data into a grid (38a) whose grid elements are marked as free or occupied in an occupancy information memory (37).

Description

The invention relates to a storage rack with a plurality of superimposed support columns for supporting storage carriers, which can be conveyed by means of an automatic loading and unloading device. The storage rack has at least one access opening for feeding and unloading the storage carriers and a computer in which information about the stored goods is stored. At least one image acquisition device is provided on the storage rack, which is suitable for the complete optical capture of the stored goods placed in the storage carriers and generates digital image information from this, wherein the digital image information is stored in the computer and can be retrieved by means of a display device. A selection device is associated with the display device, with which a storage carrier can be selected based on the digital image information and moved into the access opening by means of the computer.Furthermore, the invention relates to a method for storing and retrieving goods in such a storage rack and to a computer program product for carrying out such a method. Such storage racks are known in the prior art as vertical lifts. With these racks, a storage carrier is moved into the access opening to load or unload goods. As soon as the storage carrier is in position in the access opening, the operator can place goods into or remove them from the storage carrier. Modern storage racks of the type mentioned above have a control system that manages inventory and stores information about which goods are stored in which storage container. This allows the operator to easily locate the correct storage container. Such a storage rack is known from DE 201 21 417 U1. A digital camera, located in the loading and unloading opening, captures the stored goods on the storage carrier. The images captured by the digital camera are sent to a computer containing image capture software. This software can generate a grid system that identifies available storage spaces in the carriers and displays them on a monitor. German patent DE 297 24 869 U1 describes a storage device with a storage compartment and a lockable access opening to the storage compartment. The device includes an optical imaging device for capturing three-dimensional objects. Images generated by the imaging device are processed for display on a screen and transmitted via data lines to an electronic visualization device and then to a data processing unit for further processing. In DE 10 2006 052 659 A1 a storage rack is described in which the stored goods are optically recorded and displayed. From DE 10 2004 028 743 A1, a shelf is known in which contactless detection devices in the form of RFIDs are used. To simplify warehousing, DE 198 28 659 A1 proposes the use of light barriers in storage racks with fixed shelves on which containers for storing goods are placed. These light barriers register the removal of items from the containers and report this removal to a control unit. The invention addresses the problem of accelerating the storage process in a storage rack of the type mentioned above and simplifying storage management and the determination of free storage spaces. According to claim 1, to solve this problem in a storage rack of the type mentioned at the outset, it is proposed that the computer has an image data archive memory for archiving the digital image information of the storage carriers and an image data processing device which is designed to detect changes in the loading situation of storage carriers and to detect free storage places on the basis of the digital image information from the image data archive memory, and that the image data processing device (38) divides the digital image data into a grid (38a) whose grid elements are marked as free or occupied in an occupancy information memory (37). Advantageous embodiments of the storage rack according to the invention are the subject of dependent claims 2 to 11. In the storage rack according to the invention, the storage location of newly stored goods is automatically detected and recorded in the information about the stored goods. Likewise, free storage locations are detected by the computer based on digital image information. This has the advantage that free storage locations are detected even if the stored goods have shifted within the storage carriers. Precise positioning is no longer necessary for the detection of free storage locations, and the storage rack can be loaded with goods of any shape. The storage rack according to the invention eliminates the need for the operator to specify to the computer the position of the newly stored item on the storage carrier that has been moved into the access opening. Similarly, when removing stored items, it is no longer necessary to transmit the previous storage location to the computer. Furthermore, the selection of a storage carrier with a sufficiently large free storage space is simplified. The storage process is thus accelerated, and the reliability of the data stored regarding the loading status is increased. Advantageously, the image capture device for comparing the occupancy information storage captures an image of the stored goods carrier before and after storage or retrieval and transmits this to the image data archive storage. The image data processing device can advantageously compare the raster elements of the image captured before storage or retrieval with those of the image captured after storage or retrieval to align the occupancy information memory and, in the event of a change in a raster element, adjust the occupancy status assigned to it. Advantageously, the image data processing device can calculate a difference between the pixel of the image captured before or after insertion and the pixel of the image captured after insertion or insertion for each pixel of a raster element, and sum the differences within a raster element to calculate a similarity value. The storage rack can be equipped with a contactless scanning device for identifying stored goods. Since the operator no longer needs to manually enter the goods identification, this also speeds up the storage and retrieval process and improves the reliability of the data. The stored goods may have a wireless transponder device for identification purposes, and the storage rack may be equipped with a communication device for wireless transponders, which is designed to transmit identification data to the computer. The wireless transponder device advantageously features an RFID tag. Such tags are widely known from the prior art and are available in various forms. In particular, these tags are available as small stickers that are lightweight, compact, and easy to handle. The communication device can include an RFID receiver. Such an RFID receiver makes it possible to detect all objects marked with an RFID tag in the area of ​​the access opening and / or in the area of ​​the storage carrier contactlessly and without the need for optical accessibility, as is necessary for barcode recognition. To determine available storage space, the computer can have a size data store containing data that specifies the space requirements of certain stored goods. This improves the accuracy of a suggestion for an available storage space for a given item. The display device can be designed to show a preview of the identified free storage space. This allows an operator to orient themselves on the storage carrier while it is being removed from the storage rack and moved into the access opening, thus shortening the search for the free storage space on the carrier. For communication between units of the storage rack, it features a LAN or a CAN bus. Such communication paths operate reliably and with minimal interference in an industrial environment. Furthermore, a method according to claim 12 for storing goods in a storage rack according to the invention is proposed, in which the goods to be stored or retrieved are first identified by an operator or by the contactless detection device, the goods carrier with a determined free storage space is moved into the access opening, the goods are stored, and the occupancy information is compared in the computer. Based on the stored image data, the computer determines a free storage space, which is displayed by means of a display device, wherein an image data processing device divides the digital image data into a grid, the grid elements of which can be marked as free or occupied in an occupancy information memory. The operator can reject the storage space, whereupon another storage space is determined.Since the image data processing unit divides the digital image data into a grid, whose grid elements can be marked as free or occupied in the occupancy information, the effort required to process the image data is reduced, so that inexpensive and energy-saving components can be used for the computer and the image data processing unit. The method according to the invention enables a reliable updating of the occupancy information, minimizing the influence of operator errors. Since the identified storage location is displayed by the display device, it can be rejected by the operator, whereupon another free storage location is determined. This allows for verification of the proposed storage location. Advantageous embodiments of the method are the subject of claims 13 to 20. The image capture device can capture an image of the storage medium before and after storage or retrieval to verify the occupancy information and transmit it to the image archive storage. This records which changes were made to the storage medium by the operator. To synchronize the occupancy information memory, the image data processing unit can compare the raster elements of the image captured before or after storage with the image captured after storage or removal, and adjust the occupancy status assigned to a raster element if a change occurs. This allows the image data processing unit to identify which raster elements have been affected by changes resulting from the storage or removal process. Furthermore, the image acquisition system can perform a procedure for detecting free grid elements, in which the proportion of pixels whose color values ​​lie within an identification range is determined, and the grid element is marked as unoccupied if this proportion exceeds a defined threshold. This allows free space to be determined, particularly for newly stored goods carriers, without having to access archived image data. In one embodiment of the procedure, the image acquisition device performs the procedure for recognizing free grid elements for each grid element of a storage carrier. The computer advantageously features a database in which storage locations and / or quantities of the stored goods are recorded. This makes it easy to locate stored goods once they have been acquired. To compare occupancy information, the computer can store the storage location and the identification of the stored goods, determined using digital image data, in the database. This eliminates the need to repeat the time-consuming image data processing every time there is a request for available storage space or a specific item. The computer can generate a list of the stored goods contained in the storage container before and after the storage or retrieval process and determine the removed and stored goods by comparing the lists. This further increases the reliability of the database. Furthermore, a computer program product for carrying out the method according to one of claims 12 to 20 is proposed to solve the problem. Details and further advantages of the storage rack and the method according to the invention will become apparent from the following description of a preferred embodiment. The drawings, which only schematically depict the embodiment, illustrate in detail: Fig. 1 a storage rack with detection, display, and processing devices; Fig. 2 a block diagram of the computer; Fig. 3 a flowchart illustrating a storage or retrieval process; Fig. 4 a flowchart with a method for detecting changes in a storage carrier; Fig. 5a a photograph of a storage carrier before a storage process with a grid; Fig. 5b a photograph as in Fig. 5a after a storage process; and Fig. 6 a flowchart for a method for detecting free storage space. The storage rack 10 shown in Fig. 1 has two modules 11a, 11b arranged at a distance from each other. The modules 11a, 11b have a plurality of spaced-apart, paired support columns 14, which are arranged on opposite side walls. The support columns 14 serve to support trough-shaped storage carriers 15 in which stored goods 17 are held. Between modules 11a, 11b a conveying space 12 is provided in which a movable automatic loading and unloading device 13 is arranged, with which the storage carriers 15 can be conveyed. Module 11b has an access opening 18 through which storage carriers 15 can be inserted or removed. It is also possible to remove and / or store goods 17 from a storage carrier 15 that has been moved into the access opening 18. A computer 20 is assigned to the storage rack 10, which, among other things, serves to control the storage rack 10. A control device 22 located on the storage rack 10, as well as an independently operable inspection station 23, are connected to the computer 20 via a LAN 21, i.e., a local area network. An image acquisition device 24 in the form of a digital camera is arranged in an upper surface 19 of the access opening 18. The digital camera 24 is arranged such that it can completely capture a storage carrier 15 as it is moved into the access opening 18. To transmit digital image data to computer 20, the digital camera 24 is connected to it via LAN 21. LAN 21 is also connected to a contactless detection device in the form of an RFID receiver 26. The stored goods 17 are equipped with RFID tags 27, so that the stored goods 17 can be identified by the RFID receiver 26. The computer 20 shown in Fig. 2 is connected to the LAN 21 via a communication interface 30. The computer 20 can thus exchange data with the RFID receiver 26, the digital camera 24, and a display unit 28 via the LAN 21. Furthermore, the loading and unloading device 13 can be addressed via the LAN 21 (not shown here). The operating device 22 is accompanied by a control unit (not shown) for controlling the loading and unloading device 13, which controls the removal and storage of storage carriers 15. The computer 20 can communicate with this control unit and is thus relieved of the direct control of the mechanics of the storage rack 10. Likewise, it is also possible to operate the storage rack 10 using the operating device 22 without the computer 20. The computer 20 has a central processing unit 31, which is connected to a main memory 33 via a memory interface 32. Parts of the main memory 33 serve as image data archive storage 34, size data storage 35, inventory database 36, and occupancy information storage 37. The central unit 31 has an image data processing unit 38 for processing the image data supplied by the digital camera 24. The image data supplied by the digital camera 24 is stored together with a metadata record in the image data archive memory 34. The metadata record contains, for example, information about the photographed storage carrier 15, the date and time of the photograph, an indication of whether the image was taken before or after access by an operator, and an identification code of the operator who initiated the movement of the storage carrier 15 into the access opening 18. The size data storage 35 contains size and weight information for various stored goods 17. Each stored good 17 is assigned a part number, which can be used, for example, to retrieve the size of the stored good 17 from the size data storage 35. Also based on the part number, 36 data points relating to storage locations of goods 17 with a specific part number can be retrieved from the warehouse database. The occupancy information storage 37 contains information for each storage carrier 15 about which areas of the storage carrier 15 are occupied by storage goods 17 and which areas are free. The sequence of a storage process in the storage rack 10 is shown in Fig. 3. In a first step 40, an operator identifies a newly stored item 17a to the computer 20. This is done by bringing the RFID tag 27 attached to the stored item 17a into the reception range of the RFID receiver 26. For stored items 17a that are too small or unsuitable for attaching an RFID tag 27, identification can also be carried out, for example, by entering a part number at the operator device 22 or the inspection station 23. The operator also wears an RFID tag 27 on their clothing, which transmits the operator's identity to the RFID receiver 26. In a further step 41, the computer 20 determines the size of the stored item 17a from the size data storage 35 based on its identification. The computer 20 then searches the occupancy information storage 37 for a free storage space of sufficient size. As soon as such a storage space is found, in a further process step 42 the storage carrier 15 is moved into the access opening 18 with the free storage space. As soon as the storage carrier 15 reaches the access opening 18, an image of the storage carrier 15 is captured by the digital camera 24 in step 43. The image is processed by the computer 20 and stored in the image data archive 34 with the information that this image represents a state before an operator action. In step 44, the operator places the stored item 17a into an available storage location in the storage carrier 15. A suggestion for an available storage location is displayed on the operating device 22. Once the storage process is complete, the operator enters this information into the operating device 22. In a further process step 45, the digital camera 24 captures an image of the storage carrier 15 and transmits this image to the computer 20. The computer 20 stores the image in the image data archive 34 with a note indicating that it depicts a state following an operator action. In a comparison step 46, the computer 20 with its image data processing unit 38 compares the images recorded before and after the operator action and determines changes in the occupancy of the storage carrier. Based on these identified changes, in step 47 the warehouse database 36 and the occupancy information storage 37 are updated. To determine changes in the loading state, the image data processing unit 38 performs a procedure as shown in Fig. 4. In a first step 50, the image data processing unit 38 retrieves two images from the image data archive memory 34. The first image 39a, shown in Fig. 5a, was taken before the storage process; the second image 39b, shown in Fig. 5b, was taken after the storage process. After these images 39a, 39b have been taken from the image data archive storage 34, they are provided with a raster 38a by the image data processing unit 38 in a step 51. In step 52, the image data processing unit 38 selects a raster element to be processed. In step 53, the raster element of image 39a is compared pixel by pixel with the raster element of image 39b. If the raster elements match, as is the case, for example, for elements A3 and G1, then in step 54a the occupancy status of the raster element in the occupancy information memory 37 is not changed. However, if a change has occurred in the compared raster element between image 39a and image 39b, as is the case in raster elements C4 to C6, the occupancy status of the raster element is inverted in the occupancy information memory 37 in step 54b. In the next step 55, the image data processing unit 38 checks whether it has compared all raster elements with each other. If this is not the case, step 52 continues with a new raster element. However, if the last raster element has been compared, the detection of changes is terminated. To further improve the detection of free storage space, the image data processing unit 38 additionally performs the procedure shown in Fig. 6. For this purpose, the image data processing unit 38 first takes the image 39b, acquired after the storage process, from the image data archive memory 34. In a first step 60, a grid 38a is overlaid on the image 39b. The image data processing unit 38 selects a grid element for verification in step 61. In a step 62, the image data processing unit 38 determines the proportion of pixels of the grid element whose color values ​​lie within an identification area. The identification range is chosen so that in a grid element without stored goods, a large proportion of the pixels lie within the identification range. For example, if the base of storage container 15 is white, the identification range can extend uniformly from 80% to 100% brightness for all colors. If, however, the base of storage container 15 is black, the identification range should be set to, for example, 0% to 20% brightness. With a light green base, the identification range would, for example, extend from 80% to 100% for green and from 60% to 90% for both red and blue. After determining the proportion of pixels in the identification area, the image data processing unit 38 compares this proportion with a reference value, which in this case is set at 80%. If the color values ​​of at least 80% of the pixels of the raster element lie within the identification area, the raster element is marked as unoccupied in step 63a. Conversely, if less than 80% of the color values ​​of the pixels of the raster element lie within the identification area, the raster element is marked as occupied in the occupancy information memory 37 in step 63b. In a simplified form of the process, the color values ​​of the pixels can be converted to grayscale values ​​before comparison. However, the resulting savings in required computing power are offset by a lower accuracy in detecting free storage space. In step 64, the image data processing unit 38 checks whether it has checked all raster elements. If this is not the case, it continues with step 61 and a new raster element. If, however, all raster elements have been processed, the image data processing unit 38 ends the detection of the free storage location. To unambiguously determine which stored goods 17, 17a were stored or removed during a storage or retrieval operation, the RFID tags 27 of the stored goods 17 contained in the storage carrier 15 are queried before the storage or retrieval. The result is compared with the result of a new query after the storage or retrieval. RFID tags 27 that are newly added indicate newly stored goods 17a, while missing RFID tags 27 identify removed goods 17. The described method is also available as a computer program product intended for execution by computer 20. In this case, computer 20 is a control computer for the storage rack 10. It would also be conceivable to equip an industrial PC with an interface for the storage rack 10 or its loading and unloading device 13, as well as with an interface for the LAN 21, and to execute a corresponding computer program product on such computer 20. Instead of LAN 21, a CAN bus can be provided for communication between the units. If the field of view of the digital camera 24 is not sufficient to capture the entire storage carrier 15, several digital cameras 24 can be provided, the individual images of which can be combined by the image data processing unit 38 to form a complete image of the storage carrier 15. The storage rack according to the invention, together with the method according to the invention, offers a simple and reliable way to reduce operator errors and to accelerate the storage and retrieval process in a storage rack 10. Reference symbol list 10 Storage rack 11a Module 11b Module 12 Conveyor room 13 Loading and unloading device 14 Support beam 15 Storage carrier 17 Stored goods 17a Stored goods 18 Access opening 19 Top 20 Computer 21 LAN 22 Operator panel 23 Inspection station 24 Image capture device (digital camera) 26 RFID receiver (contactless reading device) 27 RFID tag 30 Communication interface 31 Central processing unit 32 Storage interface 33 Data storage 34 Image data archive storage 35 Size data storage 36 Warehouse database 37 Occupancy information storage 38 Image data processing device 38a Grid 39a Image 1 39b Image 2 40-47 Process steps 50-55 Process steps 60-64 Process steps

Claims

Storage rack (10) with a plurality of superimposed support columns (14) for supporting storage carriers (15) which can be conveyed by means of an automatic loading and unloading device (13), with at least one access opening (18) for feeding and unloading the storage carriers (15), with a computer (20) in which information about stored goods (17, 17a) is stored, wherein at least one image acquisition device (24) is provided which is suitable for the complete optical acquisition of the storage carrier (15) and for the optical acquisition of the stored goods (17, 17a) placed in the storage carriers (15) and generates digital image information therefrom, wherein the digital image information is stored in the computer (20) and can be retrieved by means of a display device (22, 23), wherein a selection device is associated with the display device (22).with which a storage carrier (15) can be selected on the basis of the digital image information and moved into the access opening (18) by means of the computer (20), characterized in that the computer (20) has an image data archive memory (34) for archiving the digital image information of the storage carriers (15) and an image data processing device (38) which is designed to detect changes in the loading situation of storage carriers (15) and to detect free storage spaces by comparing the digital image information from the image data archive memory (34), and in that the image data processing device (38) divides the digital image data into a grid (38a) whose grid elements are marked as free or occupied in an occupancy information memory (37). Storage rack according to claim 1, characterized in that the image capture device (38) for comparing the occupancy information storage (37) captures an image (39a, 39b) of the storage carrier (15) before and after storage or retrieval and transmits it to the image data archive storage (34). Storage rack according to claim 1 or 2, characterized in that the image data processing device (38) for comparing the occupancy information memory (37) compares the grid elements of the image (39a) captured before storage or retrieval with those of the image (39b) captured after storage or retrieval and adjusts an occupancy status assigned to a grid element in the event of a change to that element. Storage rack according to claim 3, characterized in that the image data processing device (38) forms a difference between the pixel of the image (39a) captured before storage or removal and the pixel of the image (39b) captured after storage or removal for each pixel of a raster element and sums the differences within a raster element to calculate a similarity value. Storage rack (10) according to one of the preceding claims, characterized in that the storage rack (10) has a contactless detection device (26) for detecting stored goods (17, 17a). Storage rack (10) according to claim 5, characterized in that the stored goods (10) have a wireless transponder device for identification purposes and a communication device for wireless transponders is provided to the storage rack (10) which is designed to transmit identification data to the computer (20). Storage rack (10) according to claim 6, characterized in that the wireless transponder device has an RFID label (27). Storage rack (10) according to claim 6 or 7, characterized in that the communication device has an RFID receiving device (26). Storage rack (10) according to one of the preceding claims, characterized in that the computer (20) for determining a free storage space has a size data storage (35) with data specifying the space requirement of a stored good (17, 17a). Storage rack (10) according to one of the preceding claims, characterized in that the display device (22, 23) is designed to display a preview of the determined free storage space. Storage rack (10) according to one of the preceding claims, characterized in that the storage rack (10) has a LAN (21) and / or a CAN bus for communication between units. A method for storing goods (17, 17a) in a storage rack (10) according to any one of claims 1 to 8, comprising the steps: a. Identification of the goods (17, 17a) to be stored by an operator or by the contactless detection device; b. Movement of the storage carrier (15) with a determined free storage space into the access opening (18); c. Storage of the goods (17, 17a); and d. Comparison of the occupancy information, characterized by the steps: e. Determination of a free storage space by the computer (20) based on stored image data; f. Display of the storage space determined by the computer (20) during storage by means of the display device (22, 23), wherein an operator can reject the storage space, whereupon another free storage space is determined; g.wherein an image data processing device (38) divides the digital image data into a raster (38a) whose raster elements can be marked as free or occupied in an occupancy information memory (37). Method according to claim 12, characterized in that the image acquisition device (38) for comparing the occupancy information storage (37) captures an image (39a, 39b) of the storage carrier (15) before and after storage or retrieval and transmits it to the image data archive storage (34). Method according to claim 13, characterized in that the image data processing device (38) for comparing the occupancy information storage (37) compares the raster elements of the image (39a) captured before storage or removal with those of the image (39b) captured after storage or removal and adjusts an occupancy status assigned to a raster element in the event of a change to that element. Method according to claim 14, characterized in that the image data processing device (38) calculates a difference between the pixel of the image (39a) captured before insertion or removal and the pixel of the image (39b) captured after insertion or removal for each pixel of a raster element and sums the differences within a raster element to calculate a similarity value. A method according to one of claims 12 to 15, characterized in that the image acquisition device (24) performs a method for detecting free raster elements comprising the following steps: a. Determining the proportion of pixels whose color values ​​lie within an identification area; b. Marking the raster element as unoccupied if the proportion exceeds a defined threshold. Method according to claim 16, characterized in that the image acquisition device (24) performs the method for detecting free grid elements for each grid element of a storage carrier (15). Method according to one of claims 12 to 17, characterized in that the computer (20) has a warehouse database (36) in which storage locations and / or storage quantities of the stored goods (17, 17a) are stored. Method according to claim 18, characterized in that the computer (20) when comparing the occupancy information storage (37) stores the storage location determined on the basis of the digital image information and the identification of the stored goods (17) in the storage database (36). Method according to one of claims 18 or 19, characterized in that the computer (20) creates a list of the stored goods (17) contained in the storage carrier (15) before and after the storage or retrieval process and determines the removed and stored goods (17, 17a) by comparing the lists. Computer program product for carrying out the method according to one of claims 12 to 20.

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