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Volume 24, Issue 2
Displaying 1-17 of 17 articles from this issue
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Hiroo IWATA1988 Volume 24 Issue 2 Pages 107-111
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSkin temperature has a close relationship to emotional state. The anther is proposing to define skin temperature of face as an index of mental stress. Skin temperature of face is remotely measured by thermography and digital image processing.
From the result of experiments, it is proved that skin temperature of nose area is closely connected with the conditions of mental work. Under such intensive mental work load as repetitive calculation for a long time, nose temperature of the worker become lower than those under usual mental load. In this experiment, relation between skin temperature and heart rate variability is also studied. As an evaluation index of mental work, skin temperature is superior to heart rate variability in some cases.
Mental stress of automobile driver, as a practical applicaton, is measured and effects of displaying graphic image are observed.View full abstractDownload PDF (2469K) -
Jiro OHNO, Hirokatsu YASHIRO, Yoshiyuki SHIRAKAWA1988 Volume 24 Issue 2 Pages 112-118
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSNew type of a burden sensor applied by 10GHz (X-band) microwave for measuring packing structure in a blast furnace is newly developed. This sensor is able to use at almost every part in the furnaces.
It was found that the attenuation of transmitted X-band wave in a burden layer differed between a coke layer and an ore layer, and the attenuation was kept constant regardless the change in the temperature of burdens. The change in a reflected power of X-band wave from the surface of burdens could be applied for the detection of particle size. Arranging the transmitted and reflected waves, a burden sensor was constructed. This sensor can measure the descending velocity, the thickness of burden layer and the particle size simultaneously.
A probe with an ellipsoidal cross section has three narrow slits set in a shell at the tip of it. One slit transmits an X-band wave and other two slits receive the wave scattered in a burden layer. Attaching two receiving slits above and below, boundaries of ore and coke can be detected with a certain delay of time. By using the signal corresponding to the boundaries and the delay time, the descending velocity and the thickness of layer can be obtained. The transmitted slit receives the reflected wave from the peripheral of the slit. Correcting the changing cycle of the reflected wave by the descending velicity, particle size can be obtained. An experiment at a laboratory showed that this sensor could measure these parameters within the accuracy of ±10%. Various types of microwave sonsor have been installed in a shaft, belly and bosh of several furnaces. The sensor shows stable signal for more than half a year.View full abstractDownload PDF (2236K) -
Shin-ichi MIYAMOTO, Seiichi SHIN, Shigenori OKUBO1988 Volume 24 Issue 2 Pages 119-125
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a model reference adaptive control system (MRACS) for a plant with deterministic disturbances, which are assumed to be outputs of autonomous systems. An MRACS can be designed for an augmented system which is composed of the plant and the autonomous systems. However, an MRACS with a state variable filter needs the degree of the augmented system, which is difficult to be known beforehand.
To dispense with the knowledge of the degree, we use a continuous-time dead-beat observer in stead of the finite dimensional state variable filter. The observer reconstructs the state of the augmented system by a sum of convolution integrals in a finite span of the time. Since the adaptive controller estimates these weighting functions, it does not require the degree of the autonomous system as well as that of the plant.
A new error system is proposed to prove the stability of the MRACS. Simulation results are also presented to show an effectiveness of the proposed method.View full abstractDownload PDF (849K) -
Koichi OSUKA, Toshiro ONO1988 Volume 24 Issue 2 Pages 126-133
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with a robust model following controller for nonlinear mechanical systems.
The most basic and important scheme for model following control of a nonlinear mechanical system, such as a manipulator arm, is nonlinear compensation method. In practice, it is very important to consider the robustuess of the controller.
It is well known that the adaptive control scheme and the VSS control scheme have a nature of robustness. But, it is a problem that the adaptive control scheme applied to a mechanical system can't guarantee the global asymptotic stability of the whole system, or the resulting controller is too complicated. On the other hand, the main drawback of the VSS approach is that the resulting control function is discontinuous and, consequently, the mechanical vibration might be caused by the control input.
In this paper, we show that, for nonlinear mechanical systems, the Robust Model Following Control System which has a continuous control law can be easily constructed, using an effective expression of the dynamical model of a controlled object. The design method is based on the Liapunov's second method.View full abstractDownload PDF (896K) -
Kazunori YASUDA, Shigemasa SUGIYAMA, Kazumasa HIRAI1988 Volume 24 Issue 2 Pages 134-140
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, a variable structure control algorithm for improving the speed of response of multivariable servosystems is presented. The control strategy is fundamentally based on the approach of variable structure PI control well-known for some time. In the variable structure PI control system, only P-action is applied as long as the error is sufficiently large, but I-action is implemented when the error is small. Though this control scheme seems to be reasonable and skillful, such an intuitive switching rule about the structure does not necessarily accomplish the satisfactory improvement of the transient characteristics. The variable structure servosystem considered here is composed of two subsystems to be switched over, which an optimal servosystem and the system removed integrators from it. And the control law is derived under the criterion of the integral of squared error, which is consisted of not only the structure switching rule, but the adjusting rule for the state variable of integrator at the re-connection. The latter rule plays the significant role in the improvement of the transient response. A numerical example demonstrates the advantage of the proposed variable structure control algorithm.View full abstractDownload PDF (848K) -
Shigeyasu KAWAJI, Shoichi NARAHASHI1988 Volume 24 Issue 2 Pages 141-148
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, a new method is developed for the design of an observer for the descriptor systems. At first, the observable (in the sense of Rosenbrock) descriptor system can be transformed into a regular state-space system using the concept of the generalized matrix inverse.
Secondly, the minimal order observer for the obtained regular system is constructed by using Gopinath's method. The constructed observer is of lower order than those in the literature.
Finally, if such an observer is used jointly with the controller, it is shown that the separation property, well-known in the regular theory, also holds.View full abstractDownload PDF (851K) -
Juichi MIYAMICHI1988 Volume 24 Issue 2 Pages 149-155
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers the stability conditions of sign matrices and the minimal structures of stable matrices with diagonal sign patterns (0, -, …, -), (0, 0, -, …, -) and (0, 0, 0, -, …, -). Sign matrix (sign pattern (+, -, 0) of each element of a matrix) represents the interconnection structure of a system and so this paper deals with the structural stability of linear systems. Stability of a matrix A is closely related to the digraph associated with A and the diagonal sign pattern of A. Stable matrices with minimal number of nonzero elements are fundamental for stability consideration of sign matrices. Digraphs associated with sign matrices are assumed to be strongly connected. If associated digraph is a simple loop, the matrix can be stable iff at least n-1 diagonal elements are negative. For (0, -, …, -) type n×n matrices it is found minimal structure is unique and is a simple loop with n edges. For (0, 0, -, …, -) and (0, 0, 0, -, …, -) type matrices there are many minimal structures that contain n+1 edges. Some results of computer classification and stability check done for sign matrices with diagonal sign patterns (0, 0, 0, -), (0, -, -, -), (0, 0, -, -) and (0, 0, 0, -, -) are also included in this paper.View full abstractDownload PDF (1011K) -
Toshimitsu USHIO, Ryuichi MATSUMOTO1988 Volume 24 Issue 2 Pages 156-161
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with control problems in event-driven systems and controllable firing sequences. Event-driven systems are modelled by Petri nets with external input places. A control problem discussed in this paper is whether or not there exists a controller such that the set of firing sequences in a controlled system is equal to a desired one, which is called a desired firing set. This paper introduces a concept of a controllable firing set, which is a generalization of a controllable language defined by Ramadge and Wonham. Then, it is proved that the necessary and sufficient condition for the existence of such a controller is for the desired firing set to be a controllable one.
This paper is also concerned with a generalization of the reachable problem discussed by Ichikawa, et al., which is called a target marking controllable problem in this paper, and gives the necessary and sufficient conditions for it.View full abstractDownload PDF (713K) -
Ichiro YAMADA1988 Volume 24 Issue 2 Pages 162-169
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn many mechanisms, sold friction has a bad effect on motion. Therefore, to realize faster and more accurate positioning, it is important to compensate for nonlinear solid friction acting on a positioning mechanism.
From this point of view, this paper discusses a design method for an adaptive observer which can estimate solid friction in addition to state variables, as well as a compensation method for solid friction incurred in positioning control.
First, a kind of adaptive observer for a servomoter system is introduced. When considering the nonlinear characteristics of solid friction, the adaptive observer changes its parameter values according to three signs (plus, minus and zero) of velocity. It is experimentally confirmed that the adaptive observer exhibits superior properties in contrast to other observers, whose designs ignore solid friction or regard it as a constant disturbance, etc.
Moreover, an approximate compensation method for solid friction using the abovementioned adaptive observer is proposed. It is also shown that this compensation method enables high-speed positioning for a servomotor system with solid friction.View full abstractDownload PDF (909K) -
Morio TAKAHAMA, Takashi KIMURA, Ei TOKUDA, Ryozaburo TAGAWA1988 Volume 24 Issue 2 Pages 170-175
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn earlier paper the authors proposed a method to design a robust flight control system by using continuous Utmost Compensator.
The method is applied to design a control augumentation system (CAS) for the longitudinal flight control system of a typical small aircraft.
In this paper, a new method is proposed to design a robust flight control system using discrete time Utmost Compensator with appropriate sampling interval.
The above sampling interval is determined by the following procedure.
(1) Determine the primary strip which contains all eigen values of rigid body motion in S-plane.
(2) Determine a sampling interval to reflect the bandwidth to be robust stable in the bandwidth to be low-sensitive by aliasing effect.
By choosing the above appropriate sampling interval, the problem to design a low-sensitive and robust stable control system can be transformed to a simple problem to design a low-sensitive control system.View full abstractDownload PDF (1100K) -
Katsuhisa FURUTA, Kazuhiro KOSUGE, Yoshinori SHIOTE, Hiromu HATANO1988 Volume 24 Issue 2 Pages 176-182
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents an alternative control architecture of master-slave manipulators based on the concept of Virtual Internal Model Following Control. The proposed control architecture realizes the master-salve manipulator system with functions which assist operators based on the external information from sensors as well as bilateral feedback.
In this paper, the control problem of a master-slave manipulator is formulated as the realization problem of the desired relation between a master arm and a slave arm. The virtual internal model, whose input includes the external sensory information, is used to describe the desired relation. The control system is designed so that the master arm and the slave arm tracks the desired trajectories generated by the virtual internal model.
The proposed control architecture is experimentally applied to the master-slave manipulator system with force sensors and the effectiveness of the control architecture is illustrated through experiments.View full abstractDownload PDF (1528K) -
Paulo Eigi MIYAGI, Kensuke HASEGAWA, Kouji TAKAHASHI1988 Volume 24 Issue 2 Pages 183-190
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe authors propose a Mark Flow Graph (MFG) based programming language and programming procedure for control systems for practical discrete event production systems (DEPS).
Based on the hierarchical structure of the system, the programming procedure is a top-down approach from the conceptual level to the detail level of the DEPS. The macro representation of the system described through the production flow schema (PFS) is gradually broken down to generate the MFG which represents the system specifications in detail. The textual description (MFG/PFS language) is derived from this MFG/PFS model. In this language, DEPS activities are described through modules which are organized in a tree structure corresponding to the hierarchical structure of DEPS activities.
Programming tests using this language for MFG controllers and MFG simulators have confirmed the effectiveness and validity of this language for synthesis, updating and debugging of complex systems.View full abstractDownload PDF (1014K) -
Mikio MAEDA, Shuta MURAKAMI1988 Volume 24 Issue 2 Pages 191-197
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with a self-tuning fuzzy controller. The fuzzy controller is constructed with linguistic control rules which consist of the fuzzy variables and the fuzzy sets. Each of fuzzy sets is characterized by a membership function. The self-tuning fuzzy controller has a function that the parameters of membership functions are adequately adjusted by two learning rule sets.
One is the repeated learning rule set which adjusts the parameters of membership functions of the fuzzy controller after evaluating the control results with respect to the control performances. The other is the real time learning rule set which adjusts the parameters of the fuzzy controller by evaluating the control response at the real time.
By control simulation, it is shown that the desired control results are obtained and that the usefulness of the self-tuning fuzzy controller is recognized.View full abstractDownload PDF (950K) -
Takao FUJII1988 Volume 24 Issue 2 Pages 198-200
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (364K) -
Seizo FUJII, Naoki MIZUNO, Takao KUMAZAWA, Eiko TADAKI, Kunihiro EGUTI1988 Volume 24 Issue 2 Pages 201-203
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, a discrete time adaptive control system is designed for a respirator system. The adaptive control system designed here can successfully control the CO2 concentration of the expiratory gas of the experimental animal under artificial ventilation. The advantages of the adaptive controller are demonstrated by experimental results.View full abstractDownload PDF (420K) -
Shinobu SASAKI1988 Volume 24 Issue 2 Pages 204-206
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESS -
Fumiaki GOTO1988 Volume 24 Issue 2 Pages 207-209
Published: February 29, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTwo types of Richardson-Like extrapolations for finding accurate eigenvalues of the second order differential equation using finite-difference tequniques is studied using the Mathieu type equation. Both symmetrical and asymmetrical finite-difference expressions are explored and the conclusion is that the Richardson's extrapolation is most efficient when used with the simplest symmetrical expression.View full abstractDownload PDF (367K)
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