Design of Digital Control Using Algebraic Approach

Abstract

Design of digital control system by algebraic approach is done directly in Z domain without reference to any analog design techniques. Given a plant transfer function in Z domain G (z) and a implementable desired closed loop transfer function Y (z) I R (z) , the  transfer function of the digital controller C (z) is calculated and then implemented with a digital computer, Such digital controllers ate not constrained by limitations due to physical realization of analog systems, can be simple with lower sample rate and thus suitable for low cost microcomputer-base embedded control systems. The control algorithm results in a short program that can be altered or tuned if needed.

Several control algorithms are examined and their deficiencies are investigated. This algebraic design approach is only applicable to stable, single-input single-output plants. The design approach is used to control speed of a I k W DC motor with the help of MATLAB program, the design and implementation procedures are uncomplicated. The test result to show that all digital controllers work satisfactory well