Legal requirements in some countries require vehicle manufacturers to reliably document the type, origin and manufacturing dates of the tires mounted to a vehicle. This data accompanies the vehicle and can be stored in a database in the destination country, e.g. in case a recall needs to be issued for a certain type of tire and manufacturing period. If manufacturers need to document the DOT code of tires mounted on a vehicle, it is advantageous to replace current manual labor required for this task with automatic equipment.
This paper details the results of a study performed in cooperation with a major German car manufacturer to automate the process of reading the DOT code of the tires mounted on rims directly before vehicle assembly to fulfill required tracing requirements.
Different approaches to reading the DOT code are discussed in the paper, including the difficulties that were encountered with various standard methods. Custom algorithms were developed, which were applied in the field study at the auto manufacturer's wheel plant. Several thousand wheels were recorded electronically along with auxiliary information like tire type, size, etc. Different algorithms were applied to the test data. Finally, the results of the tests are presented and discussed.