Establishment of passenger car painting production database based on RFID technology

1 Introduction

With people's increasing personalized demand for cars, car production has moved towards a consumer-led model. Current automobile production is characterized by: product diversification, serialization, mixed-flow production, batch centralized production, and rapid market launch. In addition to formulating efficient production plans, automobile manufacturers also need to establish an efficient and stable information platform to achieve effective monitoring and management of body information.

1.1 Introduction to RFID system

RFID (Radio Frequency IDentification) technology, that is, wireless radio frequency technology, can read and write vehicle body information efficiently, real-time, and accurately. It consists of an interrogator (or code reader) and many transponders (or code carriers). Its working principle After the code carrier enters the magnetic field, the code reader (antenna on the code reader) emits radio wave energy of a specific frequency to the code carrier to drive the transponder circuit to send out the internal data. At this time, the code reader will follow the The sequence receives and interprets the data and sends it to the application program for corresponding processing.

1.2 The practical significance of introducing RFID into the painting database

Informatization production management has always been an important link for manufacturing enterprises to improve production efficiency and save costs. An important Tool for coating informatization is the code reader and supporting data transmission system. However, it is difficult to adjust the precision of traditional ordinary infrared through-beam code readers, build a communication network, and establish a complete painting database. With the adoption of RFID technology, data can cover all aspects of the painting production line, such as the vehicle type and color information used to detect the body-in-white entering the painting, information on accessories used at each station, information on robot color changes, and off-line to final assembly. At the same time, many information such as parts and components that need to be prepared for final assembly are much better than traditional information reading equipment.

2. Concept of establishing database based on RFID system

2.1 Database network division structure

In terms of communication structure, RFID belongs to the I/O layer, the painting database belongs to the CCR layer, and the IT department ALC belongs to the ERP layer, as shown in Figure 1. Establish a coating database at the CCR level, and call the required data at any time. The management capabilities of parts (SP), teaching vehicles, repainting vehicles, and empty vehicles are greatly improved, and the data of normal production car bodies can be retrieved and verified. crucial role. The CCR layer database connects the painting production PLC and the IT department ALC system through the corresponding communication protocol. The system structure is shown in Figure 2. Its network division principles:

1) The overall network is divided into 4 ring networks for networking. (cc-link IE control)

2) CCR serves as the master station of three networks and sets up network modules to communicate with subnets.

3) CCR sets up three optical fiber network modules to communicate with all PLCs on site.

4) The underlying I/O equipment can use Mitsubishi or other brand PLC systems.

2.2 Basis for establishing database based on RFID technology

The communication protocol used in the establishment of the database is shown in Figure 1. The database is mainly responsible for receiving VIN DATA, sending vehicle model information, and collecting equipment information. A log will be automatically written for each communication. When communicating with ALC, the information of each work station will be notified to ALC. After receiving it, ALC will ask whether it needs to send various body information such as VIN number. When the PA-ON work station is put into the PA-ON station, the database will request the data, and ALC will send all the body information The information is sent to the database; in other work stations, the database will not request body data from ALC, and communication will be interrupted at this step, saving a lot of communication traffic and communication time. When the database communicates with the bottom end, it will first communicate with the CCR's PLC. The CCR's PLC is responsible for sending the data collected on site to the database. The database will retrieve the required information for feedback based on the information sent. The CCR's PLC receives the After the information is fed back, it will be compared with the information collected on site to determine whether to release or request again. All data of CCR's PLC comes from the data collected by the on-site RFID system.

3. Implementation form of database in coating production line

3.1 Application of RFID system in painting

Based on the good reading and writing performance and large-capacity storage characteristics of the RFID system, we established a communication method based on this technology and the installation location of the code reader, as shown in Figure 3. Before each important work station, it will be Confirm the information.

Detailed description of each point:

1) PA-ON: WBS transfers the body to PA. Here, it scans the VIN code and communicates with ALC. The body information in the ALC server corresponding to the VIN code is Stored in the RFID and the information is stored in the CCR database. Here Manual re-reading and writing is possible.

2) ED-IN: The reader reads the body information from PA-ON, sends the vehicle model information to the electrophoretic rectifier, and verifies it with the information in the CCR. It has manual re-reading and writing functions.

3) ED-HANGER/ED-DOLLY: The spreader is transferred to the trolley, and the RFID reads the body information from the ED_IN spreader. After the transfer is completed, the body information is written to the trolley, and the information is stored in the CCR. manual intervention operation

4) SEALER: Send the information passing this point to CCR.

5) UBC: The overscan point will send the vehicle model information to the robot, and verify the information in the RFID with the CCR database, providing manual intervention re-reading and writing functions.

6) WIPE: Overscan reads the RFID information, verifies it with the information in the CCR database, and then sends it to WIPE and the Chinese painting robot, while communicating with the ALC.

7) TOPCOAT: Read the RFID information at the overscan point, verify it with the information in the CCR database, and then send it to the paint robot.

INSPECTION: Read RFID information at overscan points and verify it with the information in the CCR database.

9) GBS: Read the RFID information at the overscan point and verify it with the information inside the CCR. The body information enters the GBS storage area and will be stored in the CCR database.

10) REPAIR-IN: Read the RFID information at the overscan point, verify it with the information inside the CCR, enter the body information into the repair area, and store the information in the CCR database.

11) PBS-IN: The overscanning point will send the vehicle model information to the conveying equipment, which sorts the vehicle bodies. At the same time, the information is stored in the CCR and the vehicle body information is sent to the ALC. Its terminal computer displays the vehicle body information in each sequence.

12) PA-OFF: The overscan point will send vehicle model information to CCR, perform data verification, and then send the information to ALC.

The paint shop can install 13 code readers, and a code carrier is installed on each spreader and trolley carrying the body. It is a 128-byte data storage medium, which is assigned the body VIN number, body production year, vehicle type, and model , derivation, exterior coating color, interior coating color, production number, load-carrying trolley number, interior sealant robot JOB number, UBC robot JOB number, salt corrosion code, ostrich feather robot JOB number, intermediate coating JOB number, upper coating vehicle model , top coating color number, varnish color number, varnish vehicle model, time stamp of each station, number of cycle times of the trolley, special body usage number, SP parts usage number and other information, and their addresses are strictly assigned.

3.2 Establishment of communication between PA-0N input station and database

First, after the spreader carries the car body in place, the operator will scan the VIN number and spreader number at the welding line and input them into the ALC system terminal computer. After the ALC system obtains the VIN number, it will match it with the spreader number, and at the same time, the color information, Many information such as MTOC number are bundled together and sent to the painting database. After the database obtains the information, it sends all the information to the conveying PLC. After self-judgment, the conveying PLC writes the information into the tag (TAG) and at the same time notifies the CCR PLC. When the communication is completed, the CCR's PLC will also send the completion signal to the database, which will store the data obtained from the ALC in the database. At this point, the current car body will officially have information during painting, and it will begin to enter the process processing stage. Among them, if an error occurs in the communication process, CCR's PLC will not send data signals to the conveying equipment, but will feed back to the ALC system to request data again. After the data is obtained, it is sent to the conveying equipment again to complete the communication process.

3.3 Establishment of communication between other stations and database

Among the code readers at a total of 13 points in the paint shop, except for PA-ON (input) and PA-OFF (offline), which exchange a large amount of data with the ALC system of the IT department, the other points only communicate with the ALC system. The work station passes the information, while the information of other work stations is transmitted, and the information recording is completed by the painting database. The truck number read through the conveyor is sent to the CCR's PLC program. The PLC program converts the data type and sends it to the painting database. The database makes corresponding replies based on the requested data. After the conveyor equipment obtains the relevant data, it will A signal is fed back to the PLC program of the CCR. After the CCR receives it, it will send a conveyor release signal to release the vehicle body. As for the communication of the robot equipment, the robot equipment will directly communicate with the CCR when the chain conditions are met, request data, and the database will call out the data and send it to the robot equipment.

4 Conclusion

This article mainly explains the relevant establishment concepts and establishment methods of establishing a passenger car painting database based on RFID technology. It focuses on three aspects: the application of RFID technology in painting, communication process creation with the painting database, network structure composition, and related expansion business. During the production of a complete vehicle, it goes through many management links and contains a lot of management information. The establishment of an RFID database can make up for the disadvantage that the coating production line does not have its own information management platform, allowing enterprises to grasp the status of the production line in a timely and accurate manner. Although the introduction of RFID into the existing painting production database management will bring about an increase in related costs, if the advantages brought by RFID application can be benefited to various related management fields, its application costs will be diluted by many links. Naturally The cost of vehicle manufacturing will be significantly reduced, and the application value of RFID will be further enhanced and the economic benefits will be greatly increased.