To meet these objectives, the automation team created a reliable, state-of-the-art system based on CIMPLICITY industrial automation software with a Tracker module to satisfy the following key requirements:
- Track WIP
- Capture quality defect and rework information
- Automatically generate part-supply triggers from the production lines to logistics and other subassembly areas
- Generate production and quality-related reports on the fly
- Generate tax and delivery documentation automatically
- Automatically route bodies inside the paint shop through various processes
- Ensure data integrity of the vehicle production information
- Make all the above information readily available on the desktops of management to enable real-time decision making
The system architecture consists of two high-end servers. The CIMPLICITY Tracker server implements the process logic, including WIP tracking, routing, and quality data capture. This server, which interlocks and serves data to all viewer nodes, is configured as the domain controller to which all shop floor computer nodes and PLCs are interfaced. The SFCS database, running on another server, contains such production information as schedules, model description, color code, tax ID generation, engine description, logged WIP data, quality defects, and much more.
More than 30 Velotic display stations, preloaded with CIMPLICITY software, are stationed in the body, assembly, and paint shop. The display stations are automatically updated with vehicle data as each new vehicle arrives at the station. Operators log defect data into the SFCS by clicking on the graphical image of the body parts shown on the display station screen.
To implement tracking, the shop floor is mapped into 120 regions, based on the process carried out at that region. Triggers for tracking in the body and assembly shops are received from 15 bar code readers located at key transition points. The bar code scanners are interfaced to PLCs. The PLCs are directly interfaced to the plant’s Ethernet network and communicate with the Tracker server. In the paint shop, operators can determine the location of each vehicle by tracking the carriers (hangers and dollies) that carry the vehicle using Smarteye bar code readers and limit switch signals received from the paint shop conveyor system.
To receive vehicle tracking trigger signals from the paint shop and assembly shop conveyor systems, the CIMPLICITY Tracker Server interfaces with two PLCs via Ethernet. Tracker also sends the various interlock signals and routing control signals to these PLCs. Trigger sensors indicate the vehicle ID, time stamp of the entry of the vehicle into the region, and time stamp of exit of the vehicle from the region. As the vehicle moves through each region, attributes such as chassis number, color, model type, customer information, defects, and engine number are also tracked. With this information, it is possible to determine in real-time how many vehicles are at a particular region, when each vehicle arrived at that region, or how long it spent in that region. Routing control is implemented at 13 locations in the paint shop. Using routing control, the SFCS automatically batches jobs based on model, color, and other parameters. Routing control also enables the SFCS to detect a defective body on the conveyor and routes it to rework areas.