Implementation of a Digital Controller Based on a Reduced Order Observer for an Inherently Unstable Multivariable System

Abstract

This paper describes the design methodology of a reduced order observer and digital controller for a multivariable inherently unstable electro-hydraulic system. The paper describes the experimental techniques used to identify the parameters of the system using the Signal Processing Toolbox within Matlab, and shows the use of Matlab's Control System Toolbox to design the observer and the feedback gains. The significance of signal saturation is illustrated and the means to avoid such problems in the controller are explained.