In order to maintain strict quality control of the approximately 90 000+ motor vehicles produced annually, Toyota SA Manufacturing required an automatic data capture system within its paint shop to ensure product trace ability and quality.
According to Kevin O'Neill, Managing Director of EMS South Africa, which integrated the Toyota Paint Shop RFID System, "Toyota needed a tracking and identification system that could: store the hanger ID (carrier for the vehicles - through the paint ovens, metal preparation, phosphate, electrocoating, prime paint booths/ovens, colour booths/oven etc.) And be able to transfer the ID information to another carrier (dolly) so as to track the vehicles throughout the entire plant. The ID system had to be able to withstand the very demanding chemical and high temperature environment. And, equally important, the ID system had to interface with existing PLCs and network structures." (See Tables 1 and 2).
After an in-depth analysis of the various automatic identification capture technologies in the marketplace, Toyota SA decided that radio frequency identification or RFID, was the solution. RFID involves placing a tag onto a product or product carrier and communicating data by means of radio frequency signals from the antenna (or reader/writer) to the tag.
Toyota was faced with the challenge of evaluating RFID companies to determine which provider would offer the most reliable products, the best technical support as well as the most economical solution. Of the handful of selected candidates, Toyota chose Escort Memory Systems (EMS) RFID products and network interface modules. EMS has a long history of producing innovative RFID products and a strong reputation for ensuring that each of its automation projects is a success.
Toyota's decision to use EMS products was further solidified by the fact that numerous other automotive plants worldwide used EMS RFID products with very favourable results. Johan Stoop, General Manager, MES at Toyota, states, "We were very impressed with Escort Memory Systems' HMS 150 HT read/write tags. The tags provide excellent read/write capability, large memory, and could withstand our applications high temperature and harsh conditions."
Application implementation
The tags are mounted to brackets on the vehicle carriers (dollies and hangers) that continuously pass through the paint shop process (see Figures 1 and 2). The vehicle identification data is linked to the hanger tag ID on entry to the paint shop. The hanger tag is tracked at two read stations until the vehicle is transferred to the dollies, where the dolly tag is tracked at 11 read stations until exit of the paint shop. On exit the tag ID is related to the entrance data and reissued to the vehicle.
The 13 HMS readers with integrated antenna each interface to a PC via the RS232 serial interface COM port 1. The PCs are networked to the Toyota 'tracking server'. The readers also provide the following features: MUX 32 (multidrop RS485), RS232/RS422, four input and four output points.
Stoop, reflecting back on how identification systems have evolved, states that, "Toyota used barcodes/manual entry to track vehicles but the labels could not survive the harsh paint shop environment, and you cannot write data to a barcode label. At this stage we do not write data to the tag but it is our future intention."
Toyota SA Manufacturing believes this is a further step to become a world-class manufacturer. It is Toyota's intention to apply an RF tag to the vehicle from the start of the process (body shop) right through to vehicle distribution, and they are presently proceeding with this phase by implementing the low cost EMS FastTrack range of disposable tags.
Escort Memory Systems
(031) 564 4542
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version