Abstract
〈Vol.6 No.1(2013.1)〉
Titles
[Contributed Papers]
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■ Experiment of Collision Avoidance Control Law with Information Amount
Feedback Using Vehicle Model
Yokohama National University・Takehiro HIGUCHI, ClassNK・Kensuke KOKUBU,
and Yokohama National University・Seiya UENO
This paper is on the experiment of the collision avoidance control law
with information amount feedback using a vehicle model. The collision avoidance
is a key technology for future mass transportation systems. The amount
of information obtained by the evader is treated as a physical value for
the collision avoidance feedback control. This will lower the risk of collision
when information of the environment cannot be obtained due to various reasons
and when the intruder is coming in from out-of-sight. This paper demonstrates
the effect of collision avoidance control with
information amount feedback using a vehicle model. The results show that
the control law has the ability to lower the risk of the collision and
works in the actual environment for collision avoidance with similar motion
with that of humans.
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■ Consensus Problem in Multi-Agent Systems with Communication Channel
Constraint on Signal Amplitude
Waseda University・MingHui WANG and Waseda University, JST CREST・Kenko UCHIDA
The consensus problem of multi-agent systems with communication channel
constraint is studied by providing special Laplacians of directed graphs
in this paper. Communication delays as one kind of channel constraints
in multiagent systems have been discussed in the recent literature. Different
from those works, the consensus problem with communication channel constraint
on signal amplitude is addressed in this paper. Our work shows that the
consensus can be obtained as long as some state-dependent switching parameters
are introduced into two different types of the consensus
protocols. It is shown in an identical constraint case that the system
given by one of the two protocols can reach globally asymptotically consensus
and that the system can also achieve a generalized average-consensus if
the directed graph is balanced; it is shown in a non-identical constraint
case that the other protocol can provide the system with an asymptotic
consensus. Examples have been given to illustrate the effectiveness of
the methods.
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■ Halftone Control of Distributed Generation Networks
Maizuru National College of Technology・Yuki MINAMI,
Kyoto University・Shun-ichi AZUMA, and Toshiharu SUGIE
The Smart Grid is a novel concept which integrates the power grid and the
information-communication technology in order to increase the reliability
of electricity and the efficiency of energy usage. Toward developing the
smart grid, this paper focuses on the control of distributed generation
networks composed of multiple generators such as gasengines and gas-turbines.
In this paper, we first formulate an operation mode control problem which
is to determine ON/OFF modes of the generators subject to the balance of
supply and demand. Then, as a solution to the problem, this paper proposes
a simple and useful distributed control algorithm based on the idea of
the halftoning which is one of image processing techniques. Finally, the
effectiveness of the proposed method by several numerical simulations is
evaluated. Key Words : smart gird, balance of supply and demand, distributed
generator, halftoning.
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■ Performance Analysis of Random Dither Quantizers in Feedback Control
Systems
Kyoto University・Ryosuke MORITA, Shun-ichi AZUMA, and Toshiharu SUGIE
This paper analyzes the performance of the random dither quantizers from
the viewpoint of feedback control. In particular, it focuses here on the
uniform random dither quantizers, which quantize signals by using an artificially
introduced random signal on a uniform distribution. First, an upper bound
of the performance is derived, which enables us to easily estimate the
performance of the random dither quantizers. Next, the relation between
the performance and the sampling period is clarified. Furthermore, the
former theoretical result is demonstrated by an experiment using an inverted
pendulum system.
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■ Algebraic Solutions to the Hamilton-Jacobi Equation with the Time-Varying
Hamiltonian
Osaka University・Yu KAWANO and Toshiyuki OHTSUKA
The Hamilton-Jacobi equation (HJE) with the time-varying Hamiltonian plays
an important role in the analysis and control of nonlinear systems and
is very difficult to solve for general nonlinear systems. In this paper,
the HJE with coefficients belonging to meromorphic functions is considered,
and its solutions with algebraic gradients are characterized in terms of
commutative algebra. It is shown that there exists a solution with an algebraic
gradient if and only if an Hinvariant and involutive zero-dimensional radical
ideal exists in a polynomial ring over the meromorphic functions of the
time and the state. If such an ideal is found, an algebraic gradient can
be obtained simply by solving a set of algebraic equations.
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■ Fictitious Reference Iterative Tuning of Internal Model Controllers
for Non-Minimum Phase Systems: A Laguerre Expansion Approach
Kanazawa University・Hien Thi NGUYEN, Osamu KANEKO, and Shigeru YAMAMOTO
Fictitious reference iterative tuning (FRIT) is one of the effective data-driven
tuning methods for parameters of a controller with only one-shot experiment.
This paper applies FRIT to internal model control (IMC) for linear, time
invariant, stable and non-minimum phase systems, which enables us to simultaneously
obtain a desired controller and a mathematical plant model. Here, the authors
consider the case where we do not have any information on the system. To
overcome the difficulty of treating the non-minimum phase behaviors of
the system, Laguerre expansion is used to describe the internal model.
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■ Numerical Methods for Spectrum Computation of Monodromy Operators via
Non-Causal Hold Discretization
Nara Institute of Science and Technology・Kentaro HIRATA, Kyoto University・Tomomichi
HAGIWARA, and Nara Institute of Science and Technology・Atsushi ITOKAZU
In this paper, numerical methods for the computation of the spectrum of
the monodromy operator are investigated. This operator arises in a representation
of time-delay systems from the discrete-time viewpoint and thus its spectrum
computation is connected to their stability analysis directly. Theoretically,
the proposed methods inherit the mathematical justification of the finite-dimensional
approximation via the sample and hold discretization where the approximation
is regarded (and justified) as a perturbation to the monodromy operator.
The first key idea for the current extension is to relax the requirement
on the causality of the hold operator, inspired by the fast-lifting approach.
The second idea is to employ higher order holds based on polynomial interpolations.
By combining these two, this paper derives efficient numerical methods
in which the reduction to an eigenvalue problem is guaranteed to be completely
rigorous.
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■ Dictionary-Based Compressive SLAM
Univ. of Fukui・Kanji TANAKA and Tomomi NAGASAKA
Obtaining a compact representation of a given landmark map built by mapper
robots is a critical issue for recent simultaneous localization and mapping
(SLAM) applications. This “map compression” problem is explored from
a novel perspective of the dictionary-based data compression approach in
the paper. The primary contribution of the paper is proposal of an incremental
compression approach for simultaneous mapping and map-compression applications.
An incremental map compressor is presented by employing a modified random
sample consensus (RANSAC) map-matching technique and the compact projection
technique. Experiments evaluate the presented techniques in terms of compression
speed, compactness of data and structure, and an application to the compression
distance.
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