This document summarizes a paper that investigates the robustness of linear time-invariant state observers when state and measurement variations occur. The paper applies observer theory to an internal combustion engine model and analyzes how state and sensor disturbances affect observer error dynamics and performance robustness. It was authored by S.O. Omekanda from Oakland University, T. Perkins from Oakland University, and M.A. Zohdy from Oakland University.

1. Robustness Analysis of Linear Time-Invariant
Dynamic State Observers
S.O. Omekanda*, T. Perkins**, M.A. Zohdy***
*Department of Electrical and Computer Engineering, Oakland University, Rochester,
Michigan, U.S.A.
1www.icgst.com
http://www.icgst.com/paper.aspx?pid=P1111410320

2. In this paper, we investigate the effect of state and measurement variations on
linear time-invariant state (LTI) observers’ performance robustness and error
dynamics. These observers are widely used in control engineering, and, more
recently, modern automotive powertrain applications. They have a proven and
well documented degree of reliability and efficiency in the approximation of
systems’ states. When well designed, they exhibit negligible steady state errors. In
this study, we apply observer theory to an internal combustion engine (ICE) model.
We also investigated state and sensor measurement disturbances that occur
during common operation of the system. An analysis of the change in the observer
error dynamics, and subsequent performance robustness is presented.
2www.icgst.com
http://www.icgst.com/paper.aspx?pid=P1111410320
Robustness Analysis of Linear Time-Invariant Dynamic State Observers
Abstract

3. 3www.icgst.com
Mohamed A. Zohdy received the M. Sc. and Ph. D. degrees from the University Of Waterloo,
Ontario, Canada in electrical engineering. He worked in several industries; dowty, iron and steel,
and spar. He is currently a Professor in the ECE department at Oakland University, Rochester,
MI. His research interests are in the areas of advanced control and estimation, neural, fuzzy,
chaos control, smart simulation and hybrid systems.
Oakland University
http://wwwp.oakland.edu/

4. 4www.icgst.com
I was born in Rabat, Morocco, on September 15, 1984. I received my Bachelor in Science (B.S.)
degree in electrical engineering from Pennsylvania State University, State College, in 2009 and
the Masters in Science (M.S.) degree in electrical and computer engineering from Oakland
University, Rochester, MI, in 2011. I am currently getting my Ph.D in controls engineering from
Oakland University. I have been working as a teaching and research assistant for the electrical
and computer engineering department at Oakland University during this time. I have taught and
helped students in the areas of controls and estimation theory as well as using matlab/simulink
for simulation. My research areas primarily include design, implementation and simulation of
nonlinear observers for state estimation and control, multivariable control, subsystem
interconnection with application to internal combustion engines and electric machine in
automotive applications.
Oakland University
http://wwwp.oakland.edu/

5. 5www.icgst.com
Todd A. Perkins is a Ph.D. student in the Electrical and Computer Engineering department. He earned his B.S.
in Electrical Engineering at Howard University. After spending nearly 20 years in the broadcast, automotive
and telecommunications industry, he left to pursue a M.S. and Ph.D. at Oakland University so he could teach
engineering. Under the ‘coaching’ of Dr. M.A. Zohdy, his working dissertation title is Adaptive Nonlinear
Control of Clutch Engagement in Modern Automotive Transmissions. His current research includes piecewise
linear (PWL) modeling, State Space modeling, nonlinear Adaptive Controls and Simulink modeling. Todd
enjoys working as a Teaching Assistant and teaching Science, Technology, Engineering and Math (STEM)
outreach camps to K-12 students.
Oakland University
http://wwwp.oakland.edu/

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