Design of warehouse management application based on RFID technology and WMS

1. Project Background

1.1 Background

Warehousing management is the management process of planning, organizing, controlling and coordinating warehouses and their internal materials. It plays an important role in the entire logistics and economic activities, connecting producers and consumers.

Enterprises of different sizes and product types have different warehouse management processes and needs, but the core parts include warehouse operations (in and out of the warehouse) and inventory control (transfer warehouse, inventory). However, with the changes in the production and manufacturing environment, the shortening of product cycles, the rise of diversified and small-scale production models, and the market demand has put forward higher requirements for warehouse management.

The traditional simple and static warehouse management model has problems such as huge inventory of materials, difficulty in tracking materials, low efficiency of capital and material turnover, high labor costs, and lagging Logistics Management information and means, which can no longer meet the new warehouse management needs. In order to meet these challenges, it is necessary to abandon the traditional model, actively explore new information management technologies, build a new warehouse management information system platform, coordinate the operation of each link, ensure timely and accurate warehouse entry and exit operations and real-time transparent inventory control operations, reasonably allocate warehouse resources, optimize warehouse layout and improve warehouse operation level, improve warehouse service quality, save labor and inventory space, reduce operating costs, and enhance the market competitiveness of enterprises.

1.2 System Requirements

According to the actual application experience and customer project requirements in the RFID warehouse WMS system, a high-quality warehouse management system needs to achieve the optimal warehouse resource allocation, precise warehouse operation control and real-time and effective warehouse data flow transmission. Therefore, the construction of the RFID+WMS warehouse management information system platform mainly involves the following six requirements.

1.2.1 Visual inbound and outbound management

The RFID+WMS warehouse management system should be able to realize the visual management of real-time warehouse data in the management center, including the inbound and outbound operations of goods (pallets), and realize the synchronization of physical flow and data flow through visual management.

1.2.2 Electronic pallet and storage location management

In RFID+WMS warehouse management applications, electronic pallet and storage location management is the basis for visual and intelligent warehouse management. By electronicizing pallets, the identity of each pallet can be identified and its storage and transfer location can be tracked in real time. Combined with electronic storage location management, it can provide the necessary data basis for visual warehouse management.

By dividing the physical space of the warehouse into different areas and assigning a unique label to each area, the goods in the warehouse can be effectively located and quickly retrieved.

1.2.3 Real-time inventory

By using RFID handheld terminals or mobile inventory counting machines, the physical objects in the warehouse are scanned and identified, and the physical information is generated. It is compared with ERP data to generate an inventory information table to ensure the consistency between the account and the actual items.

1.2.4 Goods search

When you need to find specific goods, you can enter the relevant goods information in the RFID handheld terminal and scan the goods within a certain range. When the target goods are scanned, the RFID+WMS warehouse management system will sound a prompt to quickly locate the goods.

1.2.5 Interface with related systems (MES/WCS/SAP)

RFID+WMS warehouse management system should not be an isolated system. It should interact with the existing production management system (MES), enterprise resource planning system (SAP) and customer system (WCS) and other related systems of the enterprise through appropriate interfaces in real time to meet the actual management needs of the enterprise.

1.2.6 Realize the unification of information flow and logistics

Due to the limitations of technical conditions, traditional warehouse management often cannot accurately reflect the warehouse inventory and logistics situation in real time, resulting in a disconnect between information flow and logistics. At the same time, manual identification of cargo information is inefficient, error-prone and labor-intensive. The ultimate goal of building an RFID+WMS warehouse management system is to unify information flow and logistics in enterprise warehouse management by introducing effective technical means, and realize real-time visual warehouse logistics management.

2. Technical background

2.1 Introduction to RFID technology

Radio frequency identification (RFID) is a new type of information technology that can realize non-contact and fast data transmission. At present, RFID technology has been widely used in production and manufacturing, anti-counterfeiting traceability, logistics and supply chain management, and has brought major technological innovations to these fields. In the field of warehousing and logistics, RFID technology can greatly improve the speed of logistics information collection and logistics operation efficiency due to its characteristics. RFID is an automatic identification technology that does not require human intervention. It automatically identifies the target object (RFID electronic tag) through radio frequency signals and obtains or records relevant data. It can work in various harsh environments without contacting the target object. A typical RFID system consists of a host computer, an RFID Reader, an antenna and an RFID electronic tag. The RFID electronic tag has a data storage area inside for storing information. The RFID reader is used to identify the electronic tag, read or write data, and complete data interaction with the host computer. The host computer is the interface that controls the operation of the entire system.

2.2 Technical advantages

The biggest feature of RFID technology is non-contact high-speed identification. It transmits data through wireless communication, and RFID electronic tags can be read without exposing electrical contacts. Therefore, even if the RFID electronic tag is pasted inside the packaging material, it can be identified. The RFID identification system can also identify multiple RFID electronic tags and high-speed RFID electronic tags at the same time, thereby achieving high efficiency in the circulation process of goods. The specific advantages are as follows:

Non-contact reading and writing

RFID technology can realize non-contact reading and writing operations. Information can be directly read into the database through the reader of the RFID system. Compared with the traditional method of manually entering information, RFID technology has obvious advantages. At the same time, RFID technology can also write various information about the logistics processing status into the tag, thereby reducing the information collection time in the next stage of the process.

Multi-tag simultaneous reading

RFID readers can identify multiple RFID electronic tags at the same time and transmit the data to the computer network system at one time. Compared with the method of scanning barcodes one by one, the data collection and item acceptance speed of RFID electronic devices can be increased by more than ten times. In addition, compared with the traditional acceptance method that relies on document entry, the multi-reading of RFID readers can achieve efficient and rapid circulation of goods.

Good penetration

Items with RFID tags can be recognized by the reader even if they are placed in non-metallic or non-transparent packaging materials (such as paper, wood, plastic, etc.). RFID technology has good penetration and can be identified without removing the items from the packaging materials, which is convenient and fast.

Large data storage capacity of tags

Compared with barcodes, RFID tags have a larger data storage capacity. Barcode technology can only indicate the type of items, but cannot express the individual information of each type of items, while RFID tags have a large storage capacity and can Store information that describes the items in detail.

Strong environmental adaptability

In some special environments, such as dirty paper, dark environment, or magnetic card loss of magnetism, traditional identification technology may not work properly. RFID technology has strong environmental adaptability, RFID tags are anti-fouling and immune, and can easily collect electronic information in the tag in a dirty or dark environment.

Reusable tags

RFID technology uses electronic chips as data storage carriers, which can repeatedly write data to achieve the reuse of tags. This feature reduces the one-time investment cost of the project and improves the sustainable utilization of tags.

Miniaturization and diversification of label shapes

The reading of RFID electronic tags is not limited by size and shape, and does not need to rely on paper of fixed size and printing quality. Compared with barcode technology, which needs to be adapted according to the shape and size of the object, the application of RFID technology on objects is more flexible and diverse. In addition, the miniaturization of RFID electronic tags also makes it more flexible to control product production on the production line.

System and data security of RFID technology

Storing product data on RFID electronic tags can provide system security and avoid reading data directly from the system, thereby improving the security of the system. In addition, RFID technology can use encryption methods to protect the data in the electronic tags to ensure that the data is not read by unauthorized.

2.3 The significance of RFID+WMS warehouse management

The application of RFID technology in warehouse management is of great significance. After years of development, RFID technology has been widely used at home and abroad, and has made great progress in the field of logistics and warehousing. RFID technology has a high degree of standardization and high technical maturity, and with the reduction of costs, it is becoming one of the standard application technologies for modern efficient warehousing and logistics.

RFID technology not only plays an important role in warehouse management, but also is one of the key technologies in the development of modern Internet of Things technology. With the support and promotion of national policies, the Internet of Things has achieved great development in many fields and has become an inevitable choice for solving the information management problems in the production, manufacturing, warehousing, logistics and other links of enterprises.

The warehouse management system (WMS) solution uses RFID technology as a key technology, which can significantly improve the technical level of warehouse and logistics management. By adopting RFID technology, enterprises can obtain a good return on investment and avoid repeated investment in information upgrades. The solution is of exemplary significance, providing reference and reference for other enterprises, and promoting the development of the entire industry.

3. RFID+WMS warehouse management system solution

3.1 Design principles of RFID+WMS warehouse management solution

Actual effect is applicable, personalized application

According to the actual situation of different warehouses, when designing the RFID+WMS warehouse management solution, factors such as site, operation mode, management mode and actual warehousing requirements should be considered. Ensure that the solution can be actually applied and produce results, and avoid unnecessary functional design. Especially when developing the RFID+WMS warehouse management software system, it is necessary to fully meet the actual management needs of the warehouse, realize personalized application, and avoid unsuitable and impractical situations.

The management model is replicable

The design of the RFID+WMS warehouse management system should focus on the main clues of warehouse management, while considering the needs of future warehouse expansion and expansion. The management model should be able to adapt to the management needs of other warehouse areas simply by copying and defining.

Controllable investment cost

On the premise of meeting management needs, control investment costs and maximize investment benefits. Avoid unnecessary investment waste, avoid repeated investment in the future, and avoid high investment but little improvement in management efficiency. Ensure that the construction cost of the RFID+WMS warehouse management system is controllable.

Controllable application risk

Ensure that the application risk is controllable when designing the RFID+WMS warehouse management system. Application risks mainly include management risks brought about by changes in new technologies and new management models to existing management models. It is necessary to fully study the existing management model, operating procedures, personnel quality and information level, and try to make a gradual and smooth transition while improving operating efficiency and management effectiveness. Avoid negative impacts of changes in management methods on business operations.

Support future expansion

Fully consider future management development needs in terms of equipment configuration, technology application and software system. When management needs increase, the RFID+WMS warehouse management system should be able to support the expansion of system functions and achieve a smooth transition.

3.2 Architecture of RFID+WMS warehouse management system

Warehouse physical layer

Includes entities such as warehouses, storage locations, pallets, forklifts, goods, and field operations. Field operations include operations such as the entry, exit, inventory, sorting, transfer, splitting, and transfer of goods. In the warehouse, each valid storage location (warehouse area) and pallet is equipped with an RFID electronic tag to achieve refined management of a single storage location (warehouse area) and pallet.

Collection and interaction layer

Includes various on-site data collection and user interaction devices, such as RFID handheld terminals and fixed RFID readers. These devices are mainly used to provide user operation guidance, real-time data collection, and data entry. Through this layer, the RFID+WMS warehouse management system can collect on-site data in real time and provide interactive operation guidance.

RFID data service layer

Manages RFID devices and related devices in the RFID+WMS warehouse management system, including data collection, data caching, data filtering, and the collection and distribution of control instructions and related data. This layer runs on the system server as a system software service, providing RFID data and related control instruction services to the user application layer and the data collection interaction layer.

Enterprise application layer

Provides a computer software user interface to the warehouse scheduling management center and the remote management center, and also provides report and data query services. Through the enterprise application layer, the RFID+WMS warehouse management system realizes functions such as planning, management control and data monitoring of warehouses and goods.

3.3 System topology diagram

In the system topology diagram, each warehouse door/channel is equipped with an RFID fixed reader, and detection antennas are installed on both sides of the door or channel to automatically detect the identity of the pallets and drivers entering and leaving. In the warehouse area, each cargo location is equipped with a cargo location electronic tag to uniquely identify the cargo location; each pallet is equipped with a pallet electronic tag to uniquely identify the identity of each pallet; each single item of goods can be equipped with a cargo electronic tag to identify the identity of the goods. In addition, the driver can carry an electronic tag to identify the driver's identity (optional). According to the on-site terrain layout, infrared, vehicle detectors and reader-writer pairing devices can also be used to detect vehicle entry and exit status.

3.4 RFID+WMS warehouse management software architecture

3.5 RFID+WMS warehouse management process design

3.5.1 Goods warehousing process

1. When goods are purchased and received or finished products are put into storage, RFID electronic tags are made and the tags are written with enterprise-defined information such as the purchasing unit, specifications and models. The electronic tags are pasted to the goods to complete the initialization of the goods information. At the same time, pallet electronic tags are installed on the pallets to identify the information of specific pallets.

2. During the process of goods entering the warehouse, the forklift tranSports the goods through the warehouse gate, and the reader-writer installed at the warehouse gate will automatically collect the RFID tag on the goods and the electronic tag information on the pallet. This information will be read and sent to the data center, and the background system will automatically bind the goods information with the pallet information to complete the entry scanning and binding operation. In this way, automatic scanning and binding can be achieved without manual intervention, and the entry operation can be automatically completed.

3. The forklift continues to transport the cargo pallet to the idle shelf. The shelf is equipped with a shelf RFID electronic tag. When the goods are put on the shelves, the RFID reader of the forklift will read the pallet label and shelf label and send the information to the data center. The backend system will automatically bind the pallet information with the shelf information, completing the

Shelf operation. This allows accurate management of shelves.

3.5.2 Cargo transfer process

When performing cargo transfer operations, the forklift client can directly initiate the transfer operation. The forklift will remove the pallet to be moved from the shelf. When the forklift's RFID acquisition system reads the cargo pallet tag information, the RFID+WMS warehouse management system will automatically unbind the pallet information from the previously bound shelf information. Then, the forklift forks the cargo to the new shelf to complete the shelving operation. During this process, the forklift will read the new shelf information in the RFID+WMS warehouse management system and upload it to the data center. The system will complete the binding of the new shelf and update the inventory information in real time.

3.5.3 Cargo outbound process

1. When the cargo is outbound, the forklift first removes the cargo pallet from the shelf. The forklift will read the pallet information in the system and send it directly to the data center. The RFID+WMS warehouse management background system will check the outbound information. If the information is correct, the de-shelf operation is completed, and the pallet information and shelf information are automatically unbound. If the information is incorrect, the system will issue an early warning.

2. After the goods are successfully removed from the shelves, the forklift will transport the goods through the warehouse gate. The warehouse gate is equipped with a reader that can automatically collect the RFID tag on the goods and the tag information on the pallet. This information will be read and sent to the data center. The RFID+WMS warehouse management background system will complete the verification of the goods label and the pallet label. If the verification is correct, the outbound operation will be completed and the inventory information will be automatically updated. If the verification is incorrect, the system will issue an early warning.

3.6 RFID+WMS warehouse management forklift deployment plan

In the RFID+WMS warehouse management system, we will use industrial PCs as forklift clients to connect with the data center, control the RFID reader on the forklift, and interact with data.

The RFID reader on the forklift is different from the general situation in the application environment. Forklifts have more stringent requirements for RFID equipment, including dustproof, waterproof and vibration-proof design. These devices need to be able to adapt to voltage and current fluctuations and have a durable, corrosion-resistant shell. In addition, these devices also need to have good temperature adaptability to adapt to various harsh working environments.