Browsing by Subject "System theory"

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Open Access
A 3D dynamic model of a spherical wheeled self-balancing robot
(2012) İnal, Ali Nail; Morgül, Ömer; Saranlı, Uluç
Mobility through balancing on spherical wheels has recently received some attention in the robotics literature. Unlike traditional wheeled platforms, the operation of such platforms depends heavily on understanding and working with system dynamics, which have so far been approximated with simple planar models and their decoupled extension to three dimensions. Unfortunately, such models cannot capture inherently spatial aspects of motion such as yaw motion arising from the wheel rolling motion or coupled inertial effects for fast maneuvers. In this paper, we describe a novel, fully-coupled 3D model for such spherical wheeled platforms and show that it not only captures relevant spatial aspects of motion, but also provides a basis for controllers better informed by system dynamics. We focus our evaluations to simulations with this model and use circular paths to reveal advantages of this model in dynamically rich situations. © 2012 IEEE.
Open Access
Decentralized blocking zeros and the decentralized strong stabilization problem
(IEEE, 1995) Ünyelioğlu, K. A.; Özgüler, A. B.; Özgüner, Ü.
This paper is concerned with a new system theoretic concept, decentralized blocking zeros, and its applications in the design of decentralized controllers for linear time-invariant finite-dimensional systems. The concept of decentralized blocking zeros is a generalization of its centralized counterpart to multichannel systems under decentralized control. Decentralized blocking zeros are defined as the common blocking zeros of the main diagonal transfer matrices and various complementary transfer matrices of a given plant. As an application of this concept, we consider the decentralized strong stabilization problem (DSSP) where the objective is to stabilize a plant using a stable decentralized controller. It is shown that a parity interlacing property should be satisfied among the real unstable poles and real unstable decentralized blocking zeros of the plant for the DSSP to be solvable. That parity interlacing property is also sufficient for the solution of the DSSP for a large class of plants satisfying a certain connectivity condition. The DSSP is exploited in the solution of a special decentralized simultaneous stabilization problem, called the decentralized concurrent stabilization problem (DCSP). Various applications of the DCSP in the design of controllers for large-scale systems are also discussed.
Open Access
Decentralized blocking zeros in the control of large scale systems
(1992) Ünyelioğlu, Konur Alp
lu lliis lliesi.s, a luuiiber ot syiithe.sis problems i'or linear. ninc-invariauL, iiiiite-cliuieiiSioiial sysiems are adclres.se(l. It i.s sliown that tlie lu'w concejU of (l·.': m inili zed blocking zeros \s as fmidaineiital to controller .synthesis problems for large scale systems as the concept of decentralized fixed modes. The main problems considered are (i) decentralized stabilization problem, (ii) decentralized strong stabilization problem, and (iii) decentralized concurrent stabilization problem. 7'he dtcenIralized siabUizaiion problem is a fairly well-understood controller synthesis problem for which many synthesis methods exist. Here, we give a new .synthesis procedure via a proper stable fractional approach and focus our attention on the generic solvability and characitnzalion of all solutions. The decenlralized strong .stabilization problem is the problem of stabilizing a .systeni using stable local controllers. In this problem, the .set of decentralized blocking zeros play an essential role and it turns out that the problem has a solution in case tlie poles and the real nonnegative decentralized blocking zeros have parity interlacing property. In the more general problem of decentralized stabilization problem with minimum number of unstable controller poles, it is shown tliat this minimum number is determined by the nuiid.H-»r of odd distributions of plant poles among the real nonnegative decentralized blocking zeros. The decentralized concurrent stabilization problem is a special type of simultaneous stabilization problem using a decentralized controller. Tliis problem is of interest, since many large scale synthesis problems turn out to be its special cases. A complete solution to decentralized concurrent stabilization problem is obtained, where again the decentralized blocking zeros play a central role. Three problems that have receiviHİ wide atteiuion in tlie literature of large scale .systems: stabilization o f composite systems using locally :>tabilizing subsystem controllers, stabilization uf composite system.^ na the slabilization o f mam diagonal transfer matrices, and rcliablt decentralized siabilizaiion problem are solved by a specialization of oiir main result on decentralized concurrent stabilization problem.
Restricted
"L"Affaire Derrida": Another Exchange
(1993) Derrida, Jacques
Open Access
Non-Markovian dynamics in ultracold Rydberg aggregates
(Institute of Physics Publishing Ltd., 2016) Genkin, M.; Schönleber, D. W.; Wüster, S.; Eisfeld, A.
We propose a setup of an open quantum system in which the environment can be tuned such that either Markovian or non-Markovian system dynamics can be achieved. The implementation uses ultracold Rydberg atoms, relying on their strong long-range interactions. Our suggestion extends the features available for quantum simulators of molecular systems employing Rydberg aggregates and presents a new test bench for fundamental studies of the classification of system-environment interactions and the resulting system dynamics in open quantum systems.
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Review Articles; The Normative Basis of Critical Theory
(1983) White, Stephen K.