Application of Adaptive Minimum-variance Control Technique for Cyclic Production Machine

In this paper, we consider the control problem of cyclic production machine. There are many mechanical parts produced by cyclic production machine. For example, springs are usually made of long stock wire which is fed into cyclic forming machine. A spring forming machine can force wire into a coiled shape during the cyclic motion, but the length of the produced spring in each cycle is varying according to the internal stress of wire, mechanical uncertainty of the forming machine etc. To improve the accuracy of free length of spring produced by forming machine, we propose an adaptive minimum-variance control strategy for cyclic production system and successfully applied to commercial spring forming machine.