Abstract
〈Vol.4 No.1(2011.1)〉
Titles
[Contributed Papers]
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■ Statistical Properties of Incremental SVMs Storing Support Vectors
Kobe Steel, Ltd.・Takemasa YAMASAKI and
Nara Institute of Science and Technology・Kazushi IKEDA
Support vector machines (SVM) are known to result in a quadratic programming
problem, that requires a large computational complexity. One way to reduce
this requirement is to apply the idea of incremental learning to SVMs,where
only a subset of given examples is stored in an iteration and the complexity
is linear with respect to the number of examples on average. When an incremental
SVM stores the set of support vectors, it has a lower performance than
an SVM in batch mode since examples that are not support vectors when given
but become ones later are neglected. This paper indirectly evaluates the
degradation of the SVM performance through the size of admissible region
under ‘disc approximation’ and verifies results using computer simulations.
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■ Feedforward Compensation Law for Constrained Systems Based on Decomposition
of Finite-Horizon Linear Systems
Osaka Prefecture University・Naoyuki HARA，
Tokyo Metropolitan University・Akira KOJIMA and
Osaka Prefecture University・Keiji KONISHI
This paper considers a control problem of constrained linear systems. By
investigating the input-output relation of finite-horizon linear systems,
we clarify pairs of input and output signals which describe the dominant
dynamics of the system. A control method is developed based on the proposed
decomposition and fundamental properties of the resulting system are discussed.
The proposed method is illustrated with numerical simulations and experiments.
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■ Development of INS-Aided GPS Tracking Loop and Flight Test Evaluation
Japan Aerospace Exploration Agency・Toshiaki TSUJII，
Takeshi FUJIWARA，Yoshimitsu SUGANUMA， Hiroshi TOMITA，
and iP-Solutions・Ivan PETROVSKI
Robust tracking of a GNSS signal in a harsh environment such as a severe
ionospheric scintillation is a challenge for the civil aviation. The use
of an inertial sensor would improve the tracking performance since the
Doppler frequency caused by aircraft dynamics could be compensated by the
inertial measurements. In order to evaluate such an aiding, an INS aided
GPS tracking loop is developed by using a software receiver, and a preliminary
flight test is conducted. A navigation grade INS tightly-coupled with GPS
as well as a low-cost MEMS INS loosely-coupled with GPS are installed to
provide aiding information. In addition, two GPS front end units with different
clock (TCXO and OCXO) are installed to collect digitized IF data. Off-line
analyses during aircraft take-off show that the noise band width in tracking
loop can be reduced to three hertz by the aiding. Also, the Doppler aiding
by a low-cost MEMS INS shows a similar performance with the aiding by a
navigation grade INS.
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■ Universal Control Formula for Feedback Linearizable Systems with Local
LQ Performance
Nara Institute of Science and Technology・Yasuyuki SATOH
，Hisakazu NAKAMURA，Nami NAKAMURA，Shizuoka University・Hitoshi KATAYAMA
and Nara Institute of Science and Technology・Hirokazu NISHITANI
In this paper, we propose a universal control formula with local LQ performance
for feedback linearizable systems. We show the inverse optimality and the
gain margin of the proposed controller. The proposed controller provides
an easy transformation method from a local LQ controller to the nonlinear
inverse optimal controller. The effectiveness of the proposed method is
confirmed by computer simulation and experiments of a magnetic levitation
system.
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■ On Internal Stabilizing Mechanism of Passive Dynamic Walking
Nara Institute of Science and Technology・Kentaro HIRATA
In this paper, the relationship between the internal stabilizing mechanism
of passive dynamic walking and linear optimal control is investigated.
In contrast to existing results, it is shown that the stabilizing mechanism
can be characterized as a special type of optimal control. After verifying
the feasibility of such a formulation numerically, it is proved that the
internal stabilizing feedback coincides with a cheap optimal control law.
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■ Extension of Reference Signals in Iterative Learning Control for Non-Minimum
Phase Systems
Deutsche Securities・Chee Leong OOI，
Osaka University・ToruASAI，
and Kumamoto University・Hiroshi OKAJIMA
This paper proposes to extend given reference signals in the iterative
learning control context so that the resultant signals have the same right
half plane zero structure as the given plants. This extension enables preventing
control inputs exponentially increasing. The extending signals can be synthesized
by solving a linear equation. The effectiveness of the proposed method
is examined by a numerical example.
▲ ■ Partial Tuning of Dynamical Controllers by Data-Driven Loop-Shaping
HiroshimaUniversity・Masami SAEKI and Yosuke SUGITANI
In this paper, a data-driven design method that gives a desirable loop-shape
is proposed for a single input plant. This method is applicable to the
tuning of a static feedback gain and also that of the output matrix of
a dynamical controller by using a transient response of the plant. Constraints
on the feedback gain are derived from the maximum sensitivity and complementary
sensitivity conditions based on the unfalsified control idea. A solution
is obtained by solving a linear matrix inequality, where the integral gain
of the loop transfer function is maximized subject to the constraints.
Usefulness is demonstrated by two numerical examples.
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■ 3D Beamforming Coupler for 2D Waveguides Using Dielectric Scatterer
Array
University of Tokyo・Yasuaki MONNAI and Hiroyuki SHINODA
We propose a novel directional antenna device that couples 2D guided microwaves
with 3D radiated beams. It consists of a dielectric scatterer array aligned
in two-dimensional periodicity on a planar surface-waveguide. Each scatterer
radiates a portion of the incident guided wave in a location-dependent
linear phase delay. Therefore, the directivity of the synthesized scattered
wave is controllable by tuning the period of the scatterers. We derive
a guideline to design the scatterer pattern for beamforming and verify
it with numerical simulations. Since the proposed method works reversibly
both on sending and receiving, microwave paths for wireless communication
and sensing can be designed smartly.
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■ Design of Dynamic Quantizers for 2-DOF IMC and Its Application to the
Temperature Control of a Heat Plate
Kumamoto University・Hiroshi OKAJIMA，
Nobutomo MATSUNAGA and Shigeyasu KAWAJI
It is well known that plants with dead-time are difficult to controll by
using traditional control methods. For this, some controllers with dead-time
have been proposed for the systems with dead-time, e.g. Internal Model
Control (IMC) and the Smith-method. However, these controllers cause another
problem, i.e. it would be difficult to realize the dead-time component
in controller because of the memory limit of micro control unit (MCU).
The sampling time has to be large in applications to the plant with large
dead-time when each data size is sufficiently kept. Hence, a trade-off
between the sampling time and the maximum quantization error exists by
the memory limit. In this paper, a design method of dynamic quantizers
is proposed for achieving small quantization error for control systems
in MCU. The effectiveness of the proposed method is shown by numerical
examples. Moreover, the proposed method is applied to a temperature control
of a heat plate. Since the input-output relation of the temperature control
system can be written with dead-time, 2-DOF IMC is introduced for this
system. It is verified that the output with the proposed quantizer approximates
the desired output under the memory limit.
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■ Reversal of Travel Time between Zipper and Non-Zipper Mergings on Highway
Traffic under the Existence of Vehicles Going Straight
University of Tokyo・Ryosuke NISHI，
Kyushu University・Hiroshi MIKI，
Meiji University，University of Tokyo・Akiyasu TOMOEDA，
University of Tokyo，Japan Society for the Promotion of Science・Daichi
YANAGISAWA and
Japan Society for the Promotion of Science，Japan Science and Technology
Agency・ Katsuhiro NISHINARI
Heavy traffic congestion often occurs at an intersection of highway traffic.
For releasing this congestion, we compare “zipper” and “non-zipper”
mergings by numerical simulations. The “zipper” merging is the alternating
merging of vehicles on two lanes and achieved only by the local communication
of vehicles before merging, while the “nonzipper” merging is the disorderly
merging of vehicles. In simulations we use a stochastic cellular automaton
model for traffic with a slow-to-start rule. Numerical results show that
the travel time of the “zipper” merging is shorter (longer) than that
of the “non-zipper” merging in the case of a strong (resp. weak) slow-to-start
effect. Moreover, it is observed that this reversal is strongly affected
by the ratio of vehicles going straight without changing lanes.
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■ Simultaneous Updating of Model and Controller Based on Fictitious Reference
Iterative Tuning
Kanazawa University・Osamu KANEKO，
Nippon Steel Corporation・MakotoMIYACHI，
and Fukui University of Technology・Takao FUJII
In this paper, we provide a new method for updating a mathematical model
of a plant and a controller, simultaneously, by using only one-shot experimental
data. Here, we propose a fictitious controller which is described by the
following triple: a nominal model of the plant, an initial controller designed
for the nominal model, and a parameterized model of the plant. In addition,
we introduce a cost function which involves the fictitious controller,
the nominal model, and the actual experimental data of the closed loop
with the initial controller. Then, for this very reason of the minimization
of the introduced cost function, we show that utilizing the fictitious
reference iterative tuning, which was proposed by the authors, enables
us to obtain both a more accurate model and a more desirable controller
than the nominal model and the initial controller, respectively. We also
give quantitative evaluation of the difference between the nominal model
and the updated one, and that between the initial controller and the updated
one. Finally, we give examples in order to illustrate the validity of the
proposed method.
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■ Fictitious Reference Tuning of the Feed-Forward Controller in a Two-Degree-of-Freedom
Control System
Kanazawa University・Osamu KANEKO，
Natural Science and Technology,・Yusuke YAMASHINA，
and Kanazawa University・Shigeru YAMAMOTO
In this paper, we provide a new effective tuning method to obtain the optimal
parameter of the feed-forward controller in a two-degree-of-freedom (2DOF)
control system for the purpose of achieving the desired response without
using a mathematical model of a plant. The first author proposed “fictitious
reference iterative tuning” (which is abbreviated to FRIT) as an effective
method for the tuning of parameters of a controller by using only one-shot
experimental data instead of using mathematical models of a plant. Here,
we extend FRIT to the tuning of the feed-forward controller
in a 2DOF control system and develop the off-line computation so as to
be done by the least squares method. For these purposes, we introduce a
new cost function consisting of the fictitious reference and the actual
data (since we do not have to do iterative computation in the least squares
method, we call the proposed method here as “fictitious reference tuning”).
Since the new cost function is quadratically-parameterized, it is possible
to analyze how far the obtained parameter is apart from the desired one.
Thus, we then derive a pre-filter which is applied to the actual data so
as to guarantee that the obtained parameter is close to the desired one.
We also show that the proposed method is applicable to the case in which
the initial experiment is performed in the conventional 1DOF control system.
Finally, we illustrate experimental results in order to show the utility
and the validity of the proposed method.
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■ A Genetic Algorithm Based Clustering Method for Optimal Route Calculation
on Multilevel Networks
Waseda University・Feng WEN，Shingo MABU and Kotaro HIRASAWA
This paper introduces a multilevel road network model to speed up the optimal
route calculation on large size road networks by preprocessing and pre-computing.
The multilevel road network is constructed by separating a large network
into several smaller sub-networks and pushing up the boundary nodes. The
new road sections on the multilevel network are decided by pre-computing
the shortest path between the boundary nodes of each sub-network in a hierarchical
manner. To optimize the structure of the multilevel road network, an effective
genetic algorithm based clustering method
is proposed, which can reduce the number of boundary nodes and road sections
between boundary nodes of each subnetwork greatly. Experimental results
show that the proposed approach significantly reduces the search space
of the route calculation algorithm over existing methods.
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