. The RFID-based warehouse management system
Fig. 1 illustrates key components of the RFID-based management system in a warehouse. At the gate of the warehouse entrance/exit, it is equipped with an RFID reader (shown at A) which collects RFID information data of RFID-tagged goods for each incoming or outgoing lorry that passes through the gate. After the process of unloading and unpacking goods (if applicable), each item will be contained in a tote entering into a storage conveyor, namely a storage rack (shown at B1). When a specific item is demanded, it can be transferred automatically from a storage rack onto an output conveyor (shown at B2) by a pusher device (shown at B). Each pusher also contains an RFID reader with its own antenna that receives wireless signals sent from each RFID-tagged item in a storage rack. Collection of inventory data by the reader is updated instantly in a warehouse management system through a controller which transmits the collected data via a middleware (shown at D). The middleware is the software translation layer between an RFID reader and the warehouse management system. Database of the warehouse management system contains records, which include data in identification, availability and other use-defined information of each item stored in the warehouse. Once an in-store item is ordered, the RFID-based inventory management system has capability to carry out an automatic check on information data of the item in database. Once the ordered item is identified by the RFID-based inventory management system, a pusher is activated by a PLC (programmable logic controller) to push the selected item in a tote onto an output conveyor. The item will then be transported by the output conveyor and it travels along an RFID-guided route to a specified destination (i.e., a collection point) for packaging (shown at C). The RFID-based warehouse inventory database will then be updated as soon as this ordered item is shifted out of the distribution centre in a lorry passing through the gate of the warehouse entrance/exit. The whole process is performed automatically without any human intervention apart from unpacking, labelling and packing operations in the warehouse.