Testing all the doors, windows, hoods and other structural components on new automobile designs and vehicles is no picnic. However, it's even harder if you have to use dedicated testing units that can handle only a few tasks and must sit idle the rest of the time. This was the challenge facing engineers in the Structural Development Lab (SDL) at General Motors' Alternative Energy Center (AEC) in Warren, Mich.
SDL's engineers conducted a June 21 press tour of their project in conjunction with the opening of Phoenix Contact's Customer Technology Center (CTC) in Ann Arbor, Mich.
"Previously, each testing cabinet had its own controller, but they had limited memory and I/O, and could only test one or two functions, such as moving windows up and down," said Albert Johnson, senior technician for the SDL. "We initially added Phoenix Contact's nanoLine PLCs, but the units were still limited in what we could do. We wanted to upgrade all of them, so we could do multiple types of tests, reduce test time, improve user interaction, and be expandable for the future."
SDL's engineers worked with Phoenix Contact to update their testing units by adding GM's proprietary, PC-based controllers and software enabled by Microsoft Windows 7 and Phoenix Contact's Valueline PCs, and by implementing more capable inline I/O to enable each to conduct more types of tests on today's more sophisticated automotive systems. Many of the controllers also are located in drawers on the cabinets, so they can be easily swapped to accommodate different tests. In addition, the testing units added new communications and networking tools, which enable SDL to run tests for users in China, Germany, Brazil and elsewhere, and then allow them to interact remotely with their tests and results at the lab in Michigan. Now in the first year of its four-year upgrade, SDL is migrating from 70 of the old dedicated cabinets to just 40 of the more adaptable units with about 20 different drawers. It also plans to send units to its facilities in Mexico, China, Korea and Brazil.
"We're writing our own software, which allows us to make any needed changes right away," says Bill Rodman, lab supervisor. "However, we're also using nanoLine's Flowchart programming and Think&Do software, which are easier to program and train users on than ladder logic. We can teach everyone to use nanoLine and Think&Do without prior programming experience. What we've ended up with is a universal controller and testing unit with a multi-display touchscreen that's easier to set up, use and troubleshoot. Engineers can sit at their desks, and log in on their PCs or smartphones to see how tests are going 24/7."
