Chrysler drives new assembly line with PCs
'We wanted to maximize machine up-time, move away from PLC technology, and greatly reduce floor space requirements for the system," says Chrysler's Kokomo, Ind. plant manager Ken Moore.To meet these requirements, Chrysler chose Cutler-Hammer's (Westville, Ohio) Open Automation Computer, Steeplechase's (Ann Arbor, Mich.
'We wanted to maximize machine up-time, move away from PLC technology, and greatly reduce floor space requirements for the system," says Chrysler's Kokomo, Ind. plant manager Ken Moore.
To meet these requirements, Chrysler chose Cutler-Hammer's (Westville, Ohio) Open Automation Computer, Steeplechase's (Ann Arbor, Mich.) Visual Logic Controller software, and Phoenix Contact (Harrisburg, Pa.) Interbus I/O blocks to form a 68 control station industrial PC system to manufacture Chrysler's rear wheel drive automatic transmission for light trucks and vans.
Maximizing machine uptime
"Our goal is a machine uptime of 85%," Mr. Moore emphasizes.
To meet this goal all PCs are of the same model and content and are configured redundantly to perform station controls, zone controls, and host task respectively.
The 68 control stations perform all control functions except computer numerical control. Six zone controllers serve as data concentrators and provide transport coordination for the synchronous line. The host PC provides statistical process control, error proofing supervision, data collection and storage, as well as MIS communications.
Chrysler recognized the advantages of reduced installation and debugging time, ease of troubleshooting, reduced cost, easier system upgrades and reduced space requirements achieved when hosting the logic control and human machine interface in the same PCs.
Using the flowchart capabilities of the Steeplechase software allowed Chrysler to design, implement, and test control station software as individual modules which closely aligned with the physical transmission manufacturing carousel's provided by Ingersoll-Rand.
"The greatest advantage of networked I/O devices was its contribution to fast machine installation. Network I/O replaced thousands of conventional device-to-I/O modules red wires with a daisy-chained Interbus cable serving Wago bit-slice and Phoenix Contact Interbus blocks," relates Mike Taylor engineering supervisor.
Leveraging this modular implementation and the benefits provided with single cable installation allowed Chrysler to reduce installation and debugging time by 4 or 5 months. Chrysler sees this modular implementation as providing on-going benefits by allowing the addition, changing or removal of a control station and it's related manufacturing carousel over a weekend.
"The future suggests a continuing flow of fast, powerful, and innovative products. Upgrades in carousel control intelligence and capabilities can be made sooner and for less cost," Mr. Moore adds.
Reducing floor space
No longer was there a need for mezzanines and offline control cabinets. Placing both the control and HMI in the PCs and through the extensive use of networked I/O devices resulted in a 50% reduction in floor space requirements.
Chrysler utilized the floorspace savings to improve the efficiency of their assembly stations.
"In short, PC applications are user-friendly to operators and skilled tradesmen. Windows-based displays have the same look and feel throughout the plant, and familiarity with PCs among young hires is making PC technology universally accepted and understood. This should translate into better quality transmissions, higher machine uptime, and greater output," Mr. Moore concludes.