A Study on the Servo-stability of the Tandem Driven Machine with Linear Motors

Abstract

Recently, linear motors have become popular as a feed drive in NC machine tools to achieve higher speed and higher accuracy. However, many problems were remained in linear motor drives. One of them is a problem related with the tandem drive. Due to its smaller force capability, plural linear motors are often used in parallel to drive an axis simultaneously. This paper presents how to achieve higher gain in the position-tandem control by preventing mutual axis interference through feedback control of properly treated velocity signals from two feedback drives. By using the proposed compensation methods, the servo stability is remarkably improved.