Making better springs using aspects of chaos theory

Abstract

This paper outlines two projects concerned with the quality testing of wire and strip metal used for the formation of springs and attempts of in-line control of a (helical) spring coiling machine for wire. The Fracmat project was a highly successful attempt to test wire for its coilability, which is known to be due to sequential variability. Methods from chaos theory, notably the Packard -Takens plot, were used to extract information that had otherwise been ignored to produce a test that could successfully distinguish between good wire and poor wire which otherwise satisfied all other available quality tolerances.