Adaptive Control in CNC Sheet Metal Processing

Abstract

Three different and complementary ways of adaptive control are presented, each working on a different time scale. All three of them are made possible due to evolutions and developments in CNC controls. The first and most popular way of adaptive control is adaptive process control. Since the process variables in sheet metal equipment change significantly in milliseconds, the control loop must also perform on a sub second time scale. The second adaptive loop is adaptive production control. Modern CNC controls know what they are manufacturing and talk with higher production software. Instead of just executing a planning that came top down, the CNC has enough knowledge of its environment that it can propose an intelligent job sequence and hence react more effectively on unforeseen situations. These adaptive loops perform on a time scale of hours and days. The third adaptive loop is adaptive resource control. To produce sheet metal parts, we need several kinds of resources: human resources, material, consumables, energy and equipment. CNC sheet metal equipment is a considerable investment. However most production managers do not know how effective their resources are being used. By applying the principles of overall equipment effectiveness, we can close the resource control loop. This loop performs on a time scale of weeks and months.