Linear Speed Control of Strip-Like Materials with a Variable Slope Current Ramp Excitation

Abstract

A very elegant method of linear speed control for strip-like materials is presented. When the strip thickness does not vary an open loop system is shown to achieve the objective with a separately excited dc motor drive whose field coil is energized with a current varying in proportion to time. For varying thickness of the strip, feedback is incorporated, resulting in precise and accurate control of linear speed by suitably modifying the excitation current. Simulated results have shown excellent corroboration of the theory. A prototype has then been constructed and a set of results obtained with it has also shown good correspondence with the theory.