Strong stabilizing of integral plus dead-time processes using first-order controllers

The stabilizing region of a stable first-order controller for an integral plus dead-time process is determined. This task is done by fixing one of the controller parameters (controller time-constant, i.e. c) and applying the D-partition method to the remaining two parameters of controller (i.e. a and b). It is proven that for any stable first-order controller, that is for any c > 0, the stability region in the (a, b) - plane is an nonempty set. Numerical simulations are included to support the theoretical results of the paper.