Publication Date


Document Type


Committee Members

Pradeep Misra (Advisor), Luther Palmer III (Committee Member), Marian K. Kazimierczuk (Committee Member)

Degree Name

Master of Science in Electrical Engineering (MSEE)


Due to inherent limitations posed by existence of zeros of a transfer function in the righthalfof the complex plane, known as non-minimum phase zeros, the issue of dealing withsuch zeros is extremely important in control of linear systems. Considerable literatureexists in control theory to try and minimize or eliminate the effect of non-minimum phasezeros. These include pole-zero cancellation, feedforward compensation, among others.These methods are only limited only to stable systems (systems with poles in the left halfof the complex plane); and will fail for systems that are unstable as well as non-minimumphase.This research focuses in designing feedforward compensators for unstable as well asnon-minimum phase. The key contribution is to decompose the transfer function of aSingle-Input Single-Output system into two sub-systems: a stable but non-minimum phasesubsystems and an unstable but minimum-phase subsystem. Then using root-locus techniques,the non-minimum phase zeros can be shifted to the left half plane, rendering thesystem minimum phase. Control techniques such as adaptive PID, model-reference control,which are not possible to implement on non-minimum phase systems can now beimplemented on the resulting system. Simulations were performed in MATLAB/Simulinkto validate the proposed compensation scheme.

Page Count


Department or Program

Department of Electrical Engineering

Year Degree Awarded