Digital controller - its design techniques

Abstract

There are different characteristics and performances of analog and digital control systems. Both systems employ the Proportional-Integral-Derivative (PID) controller. The standard functional blocks of a well-designed digital PID controller are able to accord the requirements encountering from system and computer such as: adaptation, stability, and coordination, etc. This article shows the principle functions of digital PID controllers, and how they relate to instrument and process-oriented systems. Like a lot of discrete-data systems, digital controllers are usually designed from a mathematical model of the process. Each traditional design procedures are explained and examined for appraise and comparison purpose. Designing a Direct Digital Control (DDC) system to control a simple loop is explored and can be easily extended to the multivariable systems. Also the rules of adjustment of suitable values for the controller parameters are observed. Finally, some modifications regarding the practical implementation of controllers and their applications are illustrated. The conclusion of the technical audit will strengthen some theoretical concepts and provide further insights into the existing restrictions. >