Novel Controller Design for High Order Transfer Functions Based on Similar Systems Approach

Abstract

This paper presents a new reduction method for systems with high order transfer functions. This new technique is essentially based on the nature of the three most common output responses with no overshoot, with overshoot only or with overshoot and oscillations. The approach is based on the concept of two similar systems but not identical. This similarity is made on significant weighted elements that characterize the real system. The controller will be designed based on the simple projected similar system and applied to the real or higher order systems. The characteristic of this new reduction method is that every system can be reduced to a similar first order system with same identified significant weighted elements that will be clearly defined. The merit of this new reduction technique is to avoid all mathematical equations to model the complex system and also to avoid huge mathematical equations to reduce its transfer function to an identical reduced system. The performance of the new reduction method was evaluated and compared with some reduction methods taken from the literature.