Authors:
Enrico Valtolina,
Alessandro Astolfi,
Volume: 1, Page 1637 Paper number 701
Abstract:
In the present work a discontinuous control law for chained systems
of order n that yields global asymptotic regulation and local exponential
stability in the sense of Lyapunov is proposed. As a consequence of
the Lyapunov stability property the new control law assures robustness
against the effect of (small) measurement noise and of external disturbances.
Simulation results complement the theoretical developments.
Authors:
Joseph Miller,
Wijesuriya P. Dayawansa,
Peter Hallgren,
Clyde F. Martin,
Volume: 1, Page 1643 Paper number 702
Abstract:
Existence of an internal timing mechanism in mammals has been well
established and it is known that the circadian rhythm is generated
in a bilateral structure contained in the hypothalamus called the Suprachaismatic
Nucleus (SCN) consisting of 16,000 neurons. Individually, each SCN
neuron behaves like a clock, and the ensemble of neurons are capable
of producing well synchronized and phase locked clock signals with
precise timing patterns. In this article, theory of Hopf bifurcations
in the presence of symmetries, is used to explain the functionality
and phase locking of the SCN from a systems theory viewpoint.
Authors:
Andrea Serrani,
Alberto Isidori,
Volume: 1, Page 1649 Paper number 703
Abstract:
We address the problem of output regulation for nonlinear systems driven
by a linear, neutrally stable exosystem whose natural frequencies are
not known a priori. We present a classical solution in terms of the
parallel connection of a robust stabilizer and an internal model, where
the latter is adaptively tuned to the device that reproduces the control
required to maintain the output-zeroing condition. We obtain robust
regulation (i.e. in presence of parameter uncertainties) with a semiglobal
domain of convergence for a significant class of nonlinear minimum-phase
system.
Authors:
Chunjiang Qian,
Wei Lin,
Volume: 1, Page 1655 Paper number 704
Abstract:
We prove that every chain of odd power integrators perturbed by a
C^1 triangular vector field can be stabilized in the large via
continuous state feedback, although it is not stabilizable, even locally,
by any smooth state feedback. The proof is constructive and accomplished
by developing a machinery---a continuous type of adding a power integrator---that
enables one to explicitly design a C^0 globally stabilizing feedback
law as well as a C^1 control Lyapunov function which is positive definite
and proper.
Authors:
Matthias Kawski,
Volume: 1, Page 1661 Paper number 705
Abstract:
This paper reports progress in the analysis of interconnections of
nonlinear systems, employing the chronological formalism. A fundamental
observation is the close analogy between feeding outputs of one system
back as inputs to another system and the process of Lazard elimination
which is at the root of Hall-Viennot bases and chronological products.
Possible applications of the algebraic description of interconnections
of systems include static and dynamic output feedback, and formal inversions
of systems which are of interest for tracking problems. Our description
in terms of iterated integral functionals is most readily applicable
in the case of nilpotent systems, especially strictly triangular homogeneous
systems.
Authors:
Xavier Albouy,
Laurent Praly,
Volume: 1, Page 1667 Paper number 706
Abstract:
We design and implement a controller to swing up a spherical pendulum
carried on by a three links robot arm. This controller is the patch
of two linear controllers and a nonlinear one. The latter is based
on energy and kinetic momentum assignment and relies in part on the
forwarding design technique.
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