Customers and manufacturers place particular emphasis on the safety of child protection products such as bicycle seats, helmets, strollers, and car seats. Therefore, production defects are of paramount importance and must be eliminated as much as possible. However, if the faulty part is supplied by a supplier, such defects are often beyond the manufacturer's control. Therefore, a secondary measure is to ensure a rapid and smooth product recall. Process control is achieved using an
RFID system that stores all data on product tags. Tracking systems typically use tag IDs and store relevant production data in a database, allowing access from all relevant process points. Distributed systems without permanent data links and PLCs have specific advantages: firstly, they provide mobility and independence; secondly, they reduce wiring costs.
The car seat production process involves 16 steps. Each step requires checking one characteristic. From building the base of the seat to finally packaging it into a cardboard box, every successfully completed production step must be recorded. If a workstation is missing or fails to complete successfully, it is recorded with a specific identifier. The entire process is stored in
RFID tags. Only one sequence of production steps can be verified. The system ensures the correct sequence is observed by setting a marker after each of the multiple workstations has successfully completed the assembly process. The next workstation checks the previous workstation's completion before commencing its process, and only proceeds to the next process after the check is complete.
The first workstation affixes a tag to the base of the subsequent seat. An
RFID reader checks the correct placement by reading the newly affixed tag. A robotic testing station is selected as the second workstation. This station visually inspects 16 production features of the largely completed seats. If certain features require later testing, the testing robot can select to test other features using the tags on the seats. Before the finished seats are packaged, the inspection workstation checks that all previous process steps are recorded on the tags and are合格 (qualified/compliant). The last workstation is the rework station, where seats marked as defective or missing processes are reworked.
Smaller tags should be selected because they need to be permanently affixed to the seats for process recording and timely recall in case of safety issues.
The rework station is a key component. The operator will view all necessary information on a tablet. It will show which features are incorrect and provide a reference image of the final system assembly status.
The process, especially rework, is more efficient and safer than ever before. Simply place the chair on the workstation to see which feature is problematic. The rework workstation uses a long, thin reader/writer head because the chairs do not have fixed positions or layouts; therefore, the reader/writer head needs a larger detection range to achieve full chair coverage. The long reader/writer head ensures reliable label detection in all locations. The workstation is also mobile and can inspect chairs in closed packaging boxes.
Successfully reworked chairs are ultimately placed at the end of the production line workstation, just like other chairs. A final inspection is performed here to confirm that all features are合格 (qualified/compliant). Only after confirmation are the chairs affixed with a unique serial number certification label. Afterward, the chairs are packaged in cartons; once packaged, the labels can be read using an
RFID handheld terminal without opening the carton. In case of errors, the problematic chair can be inspected at the dealership.
