Rearrangement of digital control algorithms with variable discrete pitch size

Abstract

The necessity to change the control task discreteness period can arise in the course of operation when performing a multidimensional set of tasks of digital control, filtration and control on processors having limited computing power. This can be caused, for example, by a necessity to solve more important tasks occupying the computing resources at certain moments. In this case control tasks will be solved within an increased discreteness period , which will lead to the deterioration of the system dynamics at constant parameters of the digital regulator, and even to the loss in stability of a closed digital system, which is possible with a sufficient change of the period. A rearrangement of regulator parameters (operational conversion) versus the parameter determining the rate of quantization period change is needed to recover the circuit dynamic properties. This algorithm rearrangement should be implemented automatically in the process of digital system functioning and, consequently, the rearrangement algorithms should take a fairly simple form. The present work is concerned with the rearrangement of digital control algorithms in case of a significant change in the discreteness period of the control task. The criteria of the proximity of digital regulator characteristics are given for the changed and initial discrete pitch size . Explicit formulae of digital regulator constant conversion are obtained for the simplest control laws based on the criteria presented and a methodology of control constants rearrangement is formed for the general case.