Studying the impact of climate change on machines

Temperature variation, air humidity and drafts can significantly compromise a machine tool’s accuracy. For example, a machine with a long bed accumulates heat asymmetrically during operation and bends to one side.

Manufacturing facilities in various climate zones around the world often don’t have air conditioning. That can make it challenging to precisely determine how climate and ambient conditions—such as power units and other heat sources, like hot cutting tools—will affect the way a machine functions.

The Fraunhofer Institute for Machine Tools and Forming Technology IWU, Chemnitz, Germany, wanted to study the impact of climate change on machines without having to ship them to far-flung locales. Therefore, the institute developed a climate chamber at its newly inaugurated test lab in which it could expose machines to various climates around the world.

Thanks to the removable ceiling, researchers can lift entire machine tools into the climate chamber via a crane. Image courtesy of Fraunhofer IWU.

“Exposure to sunlight and drafts causes thermal interactions in the form of structural stretching, which we are able to reproduce in the environmental chamber,” said Dr. Janine Glänzel, research scientist at Fraunhofer IWU. “The aim is to stabilize and enhance machine precision directly via a machine control system by correcting thermally induced errors during operation.”

When thermal displacements occur, she added, researchers implement corrective algorithms they developed to positively influence production accuracy. “We calculate correction values directly via a reference point on the tool, the so-called ‘tool center point,’ so that thermoelastic displacements at the point of action during production can be corrected by the machine control.”