Design of intelligent inspection system based on GPS and RFID technology

Abstract: Aiming at the problems of human error and missed inspection in the inspection of production equipment in enterprises, an intelligent inspection system based on GPS and RFID technology is designed and implemented. The system builds the central information processing system CIPS (Central Information Processing System) based on computers, uses Poeket PC as the inspection terminal PS (Portable STation), uses SQL SERver2000 relational database and SQL Server CE3.0 embedded database technology, integrates RFID technology, GPS positioning technology, information management, information transmission and other technologies, completes the information interaction between CIPS and PS, and realizes the comprehensive processing of inspection information.

The traditional inspection method is restricted by many factors such as climate conditions, environmental factors, personnel quality and sense of responsibility, and the inspection quality and completion rate cannot be guaranteed. Equipment hidden dangers cannot be discovered in time, which is easy to cause production accidents. How to supervise the inspection route and working status of the inspection personnel and the standardized management of the inspection work has become a common concern and urgent problem for enterprise production equipment managers. Therefore, in order to ensure the accuracy of the line and the smooth progress of equipment inspection, it is imperative to reform the traditional backward inspection method. The use of power lines between factory equipment for information transmission has a large noise interference and reliability cannot be guaranteed. Ultrasonic technology is relatively complicated for reading equipment information during inspection. Through investigation, analysis and demonstration of most enterprises, this paper designs and develops an inspection system based on GPS and RFID technology using VS2005 as a development tool.

1 System Overall Architecture

The intelligent inspection system based on GPS and RFID technology is mainly composed of inspection terminal PS and central processing system CIPS. The overall architecture is as follows: PPC running Windows Mobile embedded operating system is used as the basic inspection terminal PS. The PS is equipped with RFID scanning device to locate the equipment (inspection object) and is also used for location tracking. The background management system provides functions such as equipment management, inspection management and defect management. And accepts inspection data from the inspection terminal.

The system design is guided by the modular concept and is divided into two modules: CIPS software design and inspection terminal PS software design, as shown in Figure 1. Each submodule maintains relative independence, making the system both open and easy to maintain. After the entire inspection system is designed, it will be carried out according to the operation process shown in Figure 2. The inspection object information is read into the terminal database through the RFID scanning device installed on the PS, and the inspection data entry interface automatically pops up for the entry of inspection information.

Figure 1 System overall architecture

Figure 2 System on-site operation

2 CIPS Software Platform

2.1 Comprehensive Information Management Platform

The CIPS operation interface is the core of the mutual operation of each submodule. All inspection tasks are assigned to each inspection personnel through the CIPS comprehensive information management platform, and all inspection data are also saved to the database by the platform for analysis. The quality of the platform is directly related to the normal operation of the entire system. The system is designed in the following modules.

Comprehensive information display module: This module includes the functions of downloading inspection data, uploading inspection data, viewing downloaded inspection data, and re-supplementing or deleting downloaded inspection data. It can monitor the link status of the inspection terminal in real time and connect automatically.

GPS information query module: This module is used to query the path taken by a patrol officer during a patrol mission, as one of the indicators for evaluating the quality of the patrol officer's work and improving the patrol officer's work efficiency.

Information management module: responsible for managing the entry, modification and deletion of information of inspection personnel, inspection equipment and inspection objects. The information is stored in the Device table, Worker table and Mobile phone table of the database. Each time it is opened, data is obtained from the corresponding table of the database and displayed to the operation management personnel. In this interface, the corresponding information can also be added, deleted and modified, and updated in real time to the comprehensive information display module.

Data statistics module: responsible for statistical analysis of the inspection personnel's work status and equipment status, checking the inspection personnel's task completion rate, and making scientific evaluations of each inspection personnel's task completion rate for management personnel; statistical analysis of the long-term operation failure rate of the equipment.

Figure 3 Equipment failure statistics

2.2 Database establishment

The establishment of the database provides convenience for the storage of information, not only supporting the operation of the entire system in the background, but also ensuring the security of data access. Through the investigation and research of various production enterprises' power equipment and the analysis of user needs, the database adopts a three-tier structure design based on the principles of rich functions, easy expansion and security, which reduces the requirements for client system configuration. The system is mainly based on the SQLSERVER 200VER database, and 7 data tables are designed. The detailed information of each table is shown in Table 1. Another advantage of using this database is that the SQLServer database driver uses a protocol called table data flow to communicate with SQLServer, and uses ADO.NET and SQLServer 2000 database to complete the access of inspection information.

Table 1 CIPS database table

2.3 Data Transmission

The data transmission module is the key to information exchange between PS and CIPS, and its reliability determines whether the system can operate normally. This module uses the OpenNETCF.Desk-top.Communication class library to complete the transmission of CIPS and PS data, which is consistent with the mechanism of Microsoft's ActiveSync synchronization tool, and interacts with the data between the CIPS database through data replication. For the control of device connection and data replication, the timer is used to continuously search for devices connected to CIPS to check whether the terminal device has been connected to CIPS. If the connection is successful, the data will be automatically copied to CIPS, otherwise the search will continue.

3 Inspection Terminal PS

3.1 RFID Information Collection

The collection of RFID information consists of three parts: the reader, the electronic tag (TAG) and the application software system. The inspection instrument combines the provided RFID application software to develop RFID information collection software suitable for Pocket PC. The software includes a terminal information display interface and an inspection data entry interface. The terminal PS information display is displayed to the user in a table, including whether it is completed, serial number, device ID, device name, operator information, etc. Since each inspection object is equipped with an electronic tag, the RFID reader installed on the Pocket PC automatically scans the information into the terminal database, and activates the information collection software to enter the corresponding inspection data entry interface according to the specific ID information read. Inspection data entry is the key to recording data, which mainly consists of two parts, namely Device Status records the failure and normality of the inspection object, and Device Record records the detailed description of the device, as shown in Figure 4.

Figure 4 Information display interface

3.2 Embedded Database

SQLServer CE 3.0 database is a small embedded database with powerful functions and compact structure. It not only provides the basic functions of relational database, but also supports transactions and mixed data types, and occupies very little memory and other system resources. Therefore, this database is very suitable for the development of embedded systems. A small database smart.sdf based on SQL ServerCE 3.0 is designed on the PS terminal. Four data tables are designed in this database; Table 2 shows the purpose of the tables in this database.

Table 2 Terminal database table

3.3 GPS information collection

GPS information collection is used to record the inspection personnel's path information. It has the function of starting up with the PS and automatically running in the background. The developed Microsoft.WindowsMobile.Samples.Location class library is used to obtain GPS positioning information, including longitude, latitude and time. This module stores the positioning information and time in the database at regular intervals and provides it to the administrator as a factor for evaluating the inspection personnel's work status. When the terminal transmits data to the CIPS or the CIPS transmits data to the terminal, the GPS running in the background will stop writing data to the database, which can ensure that there will be no conflicts in the data transmission process. Ensure the security of data transmission. Figure 5 shows the location information storage data.

Figure 5 Obtained positioning information

4 System Testing

After the design of the inspection information management system was completed, it was intensively tested and improved in the laboratory and has been used in the logistics management of Shandong University of Science and Technology for one year. The staff first set up electronic tags for small and medium-sized power equipment in various teaching buildings and laboratory buildings on campus, and entered the equipment information, staff information and handheld terminal information into the database of the PC server. According to the on-site work tasks, the staff operated the assigned handheld terminal to conduct fault inspections on the equipment downloaded from the comprehensive information management platform.

During the application process, the system has been tested by the exchange of handheld terminals assigned by some staff and superiors, the change and re-entry of equipment information, and the replacement of inspections. The special design of the database ensures the anti-interference of the inspection data, and there is no data confusion in the database, which ensures the statistical accuracy of the final personnel task completion rate and equipment failure rate. Figure 4 shows the on-site information entered by the inspection personnel for equipment No. 4 in the No. 11 teaching building, and Figure 5 shows the positioning and time data measured by the inspection personnel in the No. 11 teaching building.

5 Conclusion

The inspection system based on GPS and RFID technology can realize the monitoring of the inspection personnel's working status, standardization and normalization of information processing, avoid the occurrence of wrong inspections and missed inspections, and effectively ensure the inspection quality of the staff. As an enterprise manager, you can easily and clearly understand each link of each inspection, including the working time of each work location in the inspection, the inspection items of each equipment, etc. It enables managers to understand the equipment status in a timely, accurate and comprehensive manner and formulate the best maintenance and repair plan. It realizes the "paperless inspection" mode of office, effectively improves the inspection management level of the enterprise's production equipment, and further ensures the safe and reliable operation of the enterprise's production.