Sitting pretty: Manufacturer brings just-in-time seat production to Canadian plantsWritten by Dominic Caranci Wednesday, 13 June 2007 19:00
In the highly competitive automotive industry, time to market is critical. Car manufacturers require their suppliers to provide them with a quality product, fast. This puts pressure on the suppliers to incorporate a manufacturing process that meets the growing demands of automakers.
Seat manufacturing, in particular, demands a high degree of versatility and flexibility. Japanese seat manufacturer TS Tech did not take this challenge sitting down. The company produces the complete seating system for the Honda Ridgeline pick-up truck at its plants in Newmarket and Markham, Ont. As a Tier 1 supplier to Honda, TS Tech is closely integrated into the vehicle assembly line. The seats required must flow just-in-time into the continuing process. That means they must be supplied in the right sequence and be the appropriate seat for each individual vehicle on the assembly line. Achieving this demands perfect logistics and a manufacturing process that permits quick changes between the widest varieties of seat type, upholstery and colour. Since there is no intermediate stock available, downtime from technical issues must be restricted to an absolute minimum.
When Honda upgraded to a new generation of seats with additional sensors integrated to increase safety - including occupancy sensors that detect not only the presence of a person, but also their approximate weight and seat position so that, in the event of an accident, the airbags deploy accordingly - TS Tech, too, had some upgrading to do where its manufacturing system was concerned.
The company's previous manufacturing system was a succession of individual workstations, which were not integrated to each other. Trouble-shooting was a very time-consuming process, since any single fault required an engineer to come to the line with a laptop, diagnose it and rectify it directly.
TS Tech turned to Siemens to update its entire manufacturing system. What resulted is a system that automatically recognizes the causes of defects, and allows increased quality with practically no downtime.
Zero defects, zero stoppages
The manufacturing system installed at TS Tech is characterized by a particularly high degree of assurance against downtime. Since Siemens provided the entire system, from the commissioning, startup and engineering design to the controls hardware, conveyors and tooling, all components integrate together without problems, and function seamlessly together. From the incoming uninterruptible power supply all the way down to the last push button, everything forms a complete solution, which underscores the concept of totally integrated automation.
The technical level of the new manufacturing system is characterized by an S7-400 PLC with a second S7-400 PLC used as a backup, along with Ethernet networking and Profibus links to the sensors and actuators. In addition, the system includes Moby RFID (radio frequency identification), AS interface fieldbus system, Step7 Graph programming language, and a WinCC user interface.
All parameters for the entire system can be displayed on the central human machine interface (HMI) station. Whether the fault is a networking problem, an incorrectly set torque gun or an operator error, PDiag, a software engineering tool used for diagnosing automation systems, allows any fault to be diagnosed and thus addressed and rectified in the shortest possible time. This tool displays the presence of a process fault automatically on the HMI. Configuration is all that is required to apply this to the system. No additional PLC or HMI programming is required by the engineers, which greatly reduces engineering and commissioning time.
Despite the complexity of the system, its flexibility allows it to be modified to satisfy future needs. Tool changes can easily be accomplished, and more stations can be added or removed as required. Even the layout can be modified without problems, if needed. Since commissioning, the system has been upgraded to increase the output by 25 per cent. This was accomplished by TS Tech's internal resources with only minor modifications.
Total quality control
The new system has not only brought the entire manufacturing process under control at TS Tech, but it has also improved quality control. The seamless monitoring of all functions generates comprehensive data on each individual product. Every individual bolt torque, the serial number of the air bags, all the test results, any rework necessary, is all logged instantly. The data is then archived on a central server for 10 years, so that causes of problems can be traced back.
TS Tech is extremely impressed with the Siemens solution. "The diagnostic capabilities of the Siemens system open up completely new opportunities for us to achieve our objectives," says Arif Khan, project manager at TS Tech.
The automatic diagnostic capability achieved with SCADA has attracted great attention at the company's head office in Japan, and has led to consideration of its adoption to other manufacturing locations worldwide.
Based on this positive experience with the Honda Ridgeline seats, TS Tech has awarded Siemens an additional turnkey system similar to the first one to produce the seats for the Honda Civic.
Today, thanks to Siemens, TS Tech is sitting pretty, as it meets Honda's deadlines and demands with no worries.
Dominic Caranci is the automotive sector manager for Siemens Canada Ltd.