Abstract
A model is presented for a wire-diameter (equivalently, the thickness of insulator) control process. It is shown that the process is described by a set of nonlinear differential-difference equations including a variable time-delay which varies dependently on a state corresponding to the wire velocity.
The stability of the second and third order systems, which correspond to the process with a proportional-type controller, is next analyzed by investigating the boundedness of solutions, the stability of linearized systems and by using digital simulations. The results show that the global stability of relevant systems could be discussed from the stability property of the linearized systems (with a constant time-delay) under the restriction that the wire velocity is always positive.
