Controllability and observability of nonlinear systems

Controllability and observability are important system properties in control theory. These properties cannot be easily checked for general nonlinear systems. This paper addresses the local and global observability as well as the decomposition with respect to observability of polynomial dynamical systems embedded in a higher-dimensional state-space. These criteria are applied on some example system.

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Connectability-Based Controllability of Large Scale Nonlinear Dynamic Thermal Systems

ASME 2009 Dynamic Systems and Control Conference, Volume 2 ◽

10.1115/dscc2009-2783 ◽

2009 ◽

Author(s):

Rahmat Shoureshi ◽

Virdi Permana

Keyword(s):

Graph Theory ◽

Nonlinear Systems ◽

Lie Algebra ◽

Large Scale ◽

Sufficient Conditions ◽

Necessary And Sufficient Conditions ◽

Rank Condition ◽

Thermal Systems ◽

Necessary And Sufficient ◽

Controllability And Observability

A new approach using graph-theory to determine the controllability and observability of large scale nonlinear dynamic thermal systems is presented. The novelty of this method is in adapting graph theory for a nonlinear class and establishing graphic conditions that describe the necessary and sufficient conditions for a class of nonlinear systems to be controllable and observable which is equivalent to the analytical method of Lie algebra rank condition. Graph theory of directed graph (digraph) is utilized to model the system and its adaptation to nonlinear problems is defined. The necessary and sufficient conditions for controllability are investigated through the structural property of a digraph called connectability. In comparison to the Lie Algebra, this approach has proven to be easier, from a computational point of view, thus it is found to be useful when dealing with large scale systems. This paper presents the problem statement, properties of structured system, and analytical method of Lie algebra rank condition for controllability and observability of bilinear systems. The main results of graphical approach which describe the necessary and sufficient conditions for controllability of nonlinear systems are presented and applied to the problem of a coupled two heat exchangers, connected in an arbitrary fashion.

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Vulnerabilities of Cyber-Physical Linear Control Systems to Sophisticated Attacks

Volume 2: Mechatronics; Estimation and Identification; Uncertain Systems and Robustness; Path Planning and Motion Control; Tracking Control Systems; Multi-Agent and Networked Systems; Manufacturing; Intelligent Transportation and Vehicles; Sensors and Actuators; Diagnostics and Detection; Unmanned, Ground and Surface Robotics; Motion and Vibration Control Applications ◽

10.1115/dscc2017-5386 ◽

2017 ◽

Cited By ~ 1

Author(s):

Verica Radisavljevic-Gajic ◽

Seri Park ◽

Danai Chasaki

Keyword(s):

Control System ◽

Nonlinear Systems ◽

Control Systems ◽

Feedback Loops ◽

Linear Control ◽

Linear Control Systems ◽

Malicious Attacks ◽

Physical Systems ◽

Controllability And Observability ◽

Time Invariant

The purpose of this paper is to examine fundamentals of linear control systems and consider vulnerability of the main cyber physical control system features and concepts under malicious attacks, first of all, stability, controllability, and observability, design of feedback loops, design and placement of sensors and controllers. The detailed study is limited to the most important vulnerability issues in time-invariant, unconstrained, deterministic, linear physical systems. Several interesting and motivations examples are provided. We outline also some basic vulnerability studies for time-invariant nonlinear systems.

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