Using RFID technology to realize automated management solutions for warehouse personnel to pick up goods

The issue of personnel permissions in the warehouse management system is a hot topic in current research. A good management system will consider the division of permissions from many aspects; if it is not appropriate, it will not only cause system instability, but also may cause important data information to be leaked. . From a security perspective, in general, we will follow the principle of least authorization when designing programs; that is, grant the minimum permissions required to the program code in the least amount of time. Unless the program requires it, the application will not be allowed to run with administrator privileges. . In a multi-functional information system integration platform, it contains multiple sub-modules, and each module may require its own unique permission system. Generally, software developers can only meet user needs by modifying the code. In most cases, the permission system is often required by users in the early stages of implementation, so designing a sound permission scheme is particularly important for information system integration platforms.

So in modern highly integrated cargo warehousing management, how to reasonably arrange personnel permissions? For a large freight warehouse, if the personnel's pickup permissions can be properly arranged, then it can greatly reduce or even avoid the issue of goods and incorrect pickups. The situation of cargo and cargo loss; thus achieving efficient automated warehousing management. This article proposes an automated personnel rights management strategy based on RFID technology, relying on the combination of software and hardware to realize automated management of warehouse personnel picking up goods.

1. Program analysis

The entire automated warehouse management personnel pick-up authority scheme is based on two foundations for in-depth research.

1) The core technology of the radio frequency identification system is the implementation of anti-collision algorithm during multi-channel access. There are two main communication methods in the RFID system: ① Wireless broadcast method, that is, there are multiple responders within the reading range of a reader/writer, and the data stream sent by the reader/writer may sometimes be received by multiple responders. ②Multiple access mode, that is, multiple responders transmit data to the reader at the same time within the scope of the reader. The former is not the focus of my consideration, but the latter will cause communication conflicts and data collision problems. At present, there are basically four solutions: SDMA-Space Division Multiple Access, Frequency Division Multiple Access (FDMA-Frequency Division Multiple Access), TDMA-Time Division Multiple Access and Code Division Multiple Access (CDMA-Code Division Multiple Access). Considering factors such as RFID system communication form, power consumption, system complexity, and cost, the TDMA method is selected to implement the anti-collision mechanism in the radio frequency identification system. The TDMA-based anti-collision algorithm is divided into: bit-based binary search algorithm and slot-based ALOHA algorithm; this solution uses a binary search algorithm to solve the anti-collision problem.

2) The basis of radio frequency identification system-the design of EPC data encoding format. The selection of EPC data encoding scheme will determine the convenient implementation of EPC data collection. In this plan, the EPC data encoding format design includes two parts: ① Design of personnel pick-up authority encoding. ② EPC coding design of cargo identification. Currently, there are 13 EPC encoding schemes, and their general structure consists of a hierarchical, variable-length header and a series of numeric fields as shown in Figure 1. The header defines the total length, identification type and EPC encoding structure, which may also include its filter value; the length of the header is variable.

2 Scheme design

The scheme design includes two parts: the cargo coding scheme design and the delivery personnel permission scheme design. In the design part of the cargo coding scheme, one of the GID-96 universal identifiers is used according to the needs of the system design. It does not rely on any existing known specifications and identification schemes, and uses a 96-bit EPC code composed of 3 fields (general manager code, object classification code, serial number). After adding the header, the uniqueness of the EPC namespace is guaranteed. Its format is shown in Table 1.

Among them, the general manager code is used to identify an organizational entity, such as a company, manager, etc.; it is responsible for maintaining the number of the following fields; the object classification code is used to identify the type or type of items under the general manager code; the serial number is used to identify each specific object under the object classification code. The codes of the three are unique, and no duplication is allowed under the same type. It can be seen from this coding format that the object classification code part represents the type of warehousing materials; it also represents the type of materials Stored in the warehouse. When a large freight warehouse has multiple pick-up personnel, this code also gives A reasonable way to allocate the authority of pick-up personnel.

In view of the fact that the pick-up personnel only target a specific logistics enterprise, their pick-up authority rarely involves external aspects; and considering the efficient operation, robustness and stability of the warehouse management system, in the design part of the coding scheme for the pick-up personnel's permissions, separate assignments are given to the pick-up personnel. Set up a custom permission encoding format. Its encoding format is still customized based on GID-96, with the purpose of making it easier to implement and more efficient when retrieving databases in batches. Its encoding format is shown in Table 2.

In the coding, there are two types of general managers: the board of directors with the highest authority and the warehouse management department in charge of different delivery personnel; each is represented by a different code. In the object classification code part: the object classification codes under the board of directors are all set to 1, which means that the board of directors has the highest authority and can check the inventory status of various materials in the current warehouse and withdraw various materials from the warehouse. Different pick-up personnel in charge of the warehouse management department have different object classification codes, which also means that different pick-up personnel carry different types of goods. In the serial number part, according to the number of personnel N, the method of using high bits is adopted: N=2M-2 (among them, M<36, all 0s and all 1s are not used, so subtract 2); the remaining 36-M bits are not considered for general use Manager and object classification, set all to 0. The check code uses cyclic redundancy check (CRC). Its biggest advantage is that it has high reliability in identifying errors. Even when there are multiple errors, it only requires a few operations. Errors can be identified; and the 16-bit CRC can verify the data integrity of 4-kilobyte-long data blocks, easily meeting the needs of RFID systems.

3 Plan implementation

First of all, when different types of materials are shipped out of the warehouse, they are implemented by pick-up personnel with different permissions. The permission of the pick-up person is represented by the "object classification code" in the EPC code. The pick-up person first reads the pick-up permission he carries with a dedicated permission reader. After the system obtains the electronic tag data, it intercepts and stores the "object classification code" in the permission tag data into a private variable through an interception instruction. When the goods are shipped out of the warehouse, the reader obtains the electronic tag of each goods, and transmits the collected electronic tags to the system through the middleware. During the transmission process, two operations are required: 1) Intercept the object classification code in the electronic label of the goods and perform a pattern matching operation on the object classification code in the electronic label with the permission of the pick-up person. When the match is successful, the inventory table in the database is traversed using the electronic label data of the material as the search condition: When the match is unsuccessful (that is, the object classification code in the label of the goods being picked up is different from the object classification code in the permission label of the person who picks up the goods), indicating that the person who picks up the goods does not have the authority to pick up the item, then the electronic label of the goods will be fed back to the LCD terminal. And it is highlighted for inspection by warehouse management personnel. 2) When the goods are successfully picked up, the goods are shipped out of the warehouse; at the same time, the database is retrieved using the electronic tag data of the goods as search conditions, and the current database warehouse material inventory table is updated; ensuring that the quantity of goods in the inventory table corresponds to that in the warehouse. This update operation is somewhat similar to the goods warehousing operation. The entire delivery operation process is shown in Figure 2.

EPC data collection part: The two operations of electronic label data collection for outbound materials and personnel authority electronic label data collection are "asynchronous". First collect the permission label data of the pick-up personnel, and then perform pattern matching with the collected electronic label data of the outbound materials. The reason for this is that the database that stores warehousing material information and the database that stores personnel permission information are managed separately. This can effectively ensure that the permission information of pick-up personnel is not leaked or stolen, and prevent the loss of warehousing materials.

Application module part: In view of the fact that when multiple readers and writers work at the same time, the number of tags they read per second is very large. Usually a buffer is opened to temporarily store electronic tag data.

In order to facilitate understanding, the author only takes any electronic tag in the EPC data queue as an example to demonstrate the entire processing process. First, the electronic tag data is dequeued and entered into the application interface.

4. Plan verification

Since EPC data collection is implemented in the hardware part, I won’t go into details here. Simulate the collected EPC data to verify the plan. The collected EPC data is stored in an EXCEL table in the form of a two-dimensional table, and the current warehouse material inventory table is stored in the ORACLE database for batch retrieval of the database. Since the batch retrieval database has very high requirements on query response time, the idea of division-sampling-matching is adopted here. The materials have been divided into simple categories during the warehousing operation. Therefore, during batch retrieval, only the first one in the inventory table of each type of warehousing material needs to be matched. When the object classification code part matches the record stored in the current inventory table, the serial number is matched; the biggest benefit of this method is: intercept once and use it multiple times. The object classification code of the batch retrieval data database will be used again when checking the personnel's permission to pick up goods. Only a temporary variable is needed to temporarily store the code: greatly reducing the interception workload and shortening the processing time.

In view of the above research, simulations were carried out in three environments in MatLab. Simulation environment 1: The inventory table records are fixed at 1,000, the outbound labels vary from 8 to 100, and the number of pick-up personnel is 1;

Simulation environment 2: There are 30 outbound labels fixed, the inventory table records changes: 100~1500, and the number of pick-up personnel is 1;

Simulation environment 3: Outbound label changes: 20~70, inventory table record changes: 150~1,450, pick-up person is 1 person; simulation results are shown in Figure 7.

It can be seen from the simulation results that this method can correctly process data and realize classification and delivery management with object classification code as the core. Compared with ordinary picking methods, the delivery time is shortened. By locking the electronic tags of goods, errors in picking up goods are reduced to a minimum, achieving the original intention of the design of the solution. It provides a new idea for modern warehouse delivery management.

  5 Conclusion

In order to achieve efficient and fast modern warehousing management, an automated management solution for personnel picking up rights based on RFID technology is proposed. Relying on the special EPC coding for pick-up personnel, the warehouse management staff's pick-up authority is reasonably allocated, which solves the problems of slow delivery from the warehouse and errors in picking up goods. However, judging from the characteristics of the design permission coding itself, this delivery permission scheme has certain limitations. When there are many types of warehousing materials, giving each warehouse manager only the right to pick up one type of goods may not be able to meet the flexibility needs of warehouse management, resulting in a waste of warehouse managers and increased investment costs in warehousing management. This is also where this program needs to be improved in the next step.