Communications & Networks
No strings attached: Wireless solutions for automotive factory floors
October 19, 2011 by Joseph Citrano and Todd Hanson
With flexibility, cost savings and user-friendly characteristics, wireless technologies today can be seen in many applications and industries. One more recent arrival to the wireless scene is the automotive factory floor.
In an industry where the stakes are high, competition is fierce and finances are tight, any change in factory assembly lines not only has to make fiscal sense, but also has to provide advantages that will keep production levels competitive.
As automotive companies have begun to stabilize, more and more are turning to the efficiencies wireless technologies can provide. The applications on an automotive factory floor that can benefit from moving to wireless switch technology include engine block transmission case machining centres; engine block boring tables; automated assembly lines; engine block conveyors travelling from heat-treating process ovens; automated robots; and operator line switches. The signal is transmitted wirelessly from the switches on the machine to a receiver that then communicates with a standard PLC or controller.
Engine block transmission case machining centres: A switch is used for verification that an engine block is locked securely in the fixture of the machining centre. Such indication is important to personnel safety, machine integrity and a high quality, final product. The switch is placed on a moveable head or fixture, which rotates during the manufacturing process, changing planes or axis as needed. Wired switches or sensors commonly fail due to the constant flexing of the wire during fixture rotation, and metal chips and cutting fluid eventually abrade the wires, resulting in production downtime. Wireless eliminates these issues.
Engine block boring tables: The switches on a fixture table rotate 180 degrees during the boring and decking operation inside a machining cell. The constant flexing of the wire in a wired switch product leads to wire breakage. In addition, the metal chips from the machining process eventually wear down the wire sheathing. A wireless switch and receiver eliminate these problems.
Automotive assembly lines: Switches on an automated assembly line identify pallet placement position at each assembly station, which can add up to hundreds of stops within an automotive line. Traditionally, wired switches are located under the conveyor and the wire is run through a tunnel located in the floor under the line. If the wiring fails, it is often difficult to access the wire for troubleshooting. Re-tooling and reconfiguration are not only costly, but any extended downtime adds up quickly in lost revenue. At a minimum, paid factory employees are in idle production mode. On the other end of the spectrum, thousands of dollars are being lost due to the halting of vehicle manufacturing. In just two minutes, an assembly line that is down can put factory production behind by an entire vehicle. A wireless switch and receiver allows easy troubleshooting and flexible reconfiguration options.
Another assembly line application for wireless technology is associated with body position fixturing devices, which hold and verify the vehicle body position on an assembly line. The integrity of wired technologies on the moving parts is compromised, causing costly re-tooling and reconfiguration expenses. Today’s wireless switch functionality can be applied into such positioning fixtures, improving the life, reliability and re-configurability of the line.
Engine block conveyor from heat-treating process ovens: Excessive heat and hard wires often do not fare well together, causing automation plant factory managers to deal with wiring damage. One example is the switch on conveyors that carry engine blocks from the heat-treating process ovens to machining lines. Over time, the heat affects the wires and connectors, leading to thermal fatigue and maintenance issues. Wireless switch solutions eliminate this problem.
Automated robots on assembly lines: Assembly line robots are doing more and more of the dirty work on automotive factory lines, and play an important role in productivity. Switches are essential in keeping the robots operating safely, ensuring that the minimum and maximum arm positions are kept within specified parameters for safe and efficient performance. Due to the constant movement, wires and connectors suffer degradation, and re-configuration is difficult and costly when these components fail. Wireless switches are not affected by the movement and help to ensure the robots stay on schedule. In some cases, since the switches are not tethered by wires, they can be relocated based on the operating area the robot is working within at any specific time. If this area changes, the switch can be relocated to meet the needs of the newly defined area.
Operator line switches: Switches with manual actuators are located at various stations within an automated assembly line. Operators trigger the switch when a problem occurs on the line. A tethered wire connection often limits access to the switch and adds wire complexity. If the wire fails, troubleshooting and eventual replacement can equate to lost productivity. Wireless solutions today offer far greater flexibility in terms of remote actuation, faster response, flexibility in switch placement and a reduced total cost.
In all of the applications mentioned, a common advantage of wireless is the reduction of connectors or connection points. Connections are one of the greatest causes of maintenance issues and lost production.
This is just the beginning. Current adapters of wireless technology in automation are seeing the additional reliability, security and user-friendly attributes, as well as reduced maintenance, lower installation costs and flexibility that going wireless has provided. And it’s only going to get better.
Solutions are being developed to expand on the current technologies serving the industry, making the technology even more flexible and robust for automotive production lines looking to increase their productivity and balance sheet.
As more and more automated factory lines turn to wireless, a few questions remain. What type of technical support comes with a wireless investment? Will the technology be forward and backward compatible with software? Who will maintain the software and codes? These service-related questions are – and should remain – standard during the decision-making process.
Choosing a wireless technology supplier is just as important as choosing to go wireless in the first place. Product support, replacement parts, the ability to package product to accommodate current and future electronics and software all make up a portion of the ROI on a chosen technology. Service providers and manufacturers emerge quickly when opportunities present themselves, so be sure to conduct your due diligence.
When it comes to wireless solutions, this is the only sure way to know that there really are no strings attached.
Joseph Citrano III is the wireless product manager with Honeywell Sensing and Control. Todd Hanson is the director of strategic marketing and wireless solutions with Honeywell Sensing and Control.
This article originally ran in the October 2011 issue of Manufacturing AUTOMATION.