All issues
Volume 32, Issue 1
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Muneyuki YOSHIOKA1996 Volume 32 Issue 1 Pages 1-7
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with the effect of the added mass due to the fluid on the natural frequency of compact transducers for low pressure measurements. An approximate model of pressure transducers is presented by the radiation impedance of a piston, the piston model of a measuring diaphragm (second order system), and the cavity impedance.
On the basis of this model, it is shown that the natural frequency of fluid-loaded pressure transducers, fF, can be expressed by the added mass due to the fluid, and the spring constant kP and equivalent mass mP of the diaphragm. The values kP and mP are estimated by two ways. One is from the natural frequency of a transducer in the atmosphere, fA, or the natural frequency of a water-loaded transducer, fW, the other is from fA and fW. The fF is evaluated by experiments for several kinds of liquid. The result obtained from fA or fW is fairly good, and the result obtained from fA and fW is very good.View full abstractDownload PDF (2150K) -
Hansheng WU, Koichi MIZUKAMI1996 Volume 32 Issue 1 Pages 8-15
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSConstant or time-varying delay is often encountered in various engineering systems to be controlled, such as chemical processes, long transmission lines in pneumatic, hydraulic, and rolling mill systems, and the existence of the delay is frequently a source of instability. On the other hand, it is not avoidable to include some degrees of uncertainty in practical control systems due to modelling errors, measurement errors, linearization approximations, and so on. Therefore, the problem of robust control for uncertain dynamical systems with time-delay has received considerable attention, and some solution approaches have been developed.
In this paper, we consider the problem of robust control for linear dynamical systems with both time-varying delay and uncertainties. Firstly, we consider time-delay systems with structured uncertainties, and by employing some analytical methods, derive some sufficient conditions for robust stability of uncertain closed-loop time-delay systems under a memoryless linear feedback controller. Secondly, we extend the above results to time-delay systems with unstructured uncertainties, and discuss some related problems.
It worth pointing out that in this paper, delay is assumed only to be any nonnegative continuous and bounded function on time. Therefore, the results obtained here may be applied to systems with uncertain delays due to the developed sufficient conditions independent of delay. Moreover, a numerical example is given to demonstrate that the robust stability conditions developed in this paper are less conservative than those reported in the control literature.View full abstractDownload PDF (1281K) -
Takao WATANABE, Keiichiro YASUDA, Ryuichi YOKOYAMA1996 Volume 32 Issue 1 Pages 16-25
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper we derive the reduced order solution of the nonstandard H∞ control problem where the direct feedthrough term from the control input to the controled output is row full rank or that from the external input to the measurement output is colum full rank. More specificaly, we give a reduced order algeblaic Riccati equation which is one of the solvability condition of the problem and derive the reduced order H∞ controller. The order of the H∞ controller is equal to that of the reduced order observer based output controller. A numerical example will show the effectiveness of this result.View full abstractDownload PDF (1376K) -
Yoshihiko MIYASATO1996 Volume 32 Issue 1 Pages 26-34
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA design method of globally bounded robust adaptive controllers is proposed in the present paper. On the assumption that the overall system is minimum phase and that the relative degree of it is known exactly, it is shown that 1) the resulting adaptive control system is globally bounded in the presence of arbitrarily large unmodeled parts of the process, and for arbitrary initial conditions, 2) even if unmodeled parts of arbitrary magnitudes exist, the output error converges to a residual region whose amplitude can be made arbitrarily small, and 3) when unmodeled parts of the process are absent in the ideal case, the zero residual tracking error is attained. This can be done by introducing two types of adaptive controllers into the control schemes, one of which is composed of linear compensators and adjusted for the modeled (nominal) part of the process, and the other is of nonlinear high gain feedback-based compensators and tuned for the unmodeled part (unknown parasitics and disturbances) of the process.View full abstractDownload PDF (1276K) -
Toru ASAI, Shinji HARA1996 Volume 32 Issue 1 Pages 35-44
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we consider a problem of the simultaneous controller synthesis and modeling for robust control against parametric perturbations. The model is formulated by an LFT representation of a norm bounded uncertainty matrix and a coefficient matrix which represents the uncertainty bound. The modeling of the uncertainty bound is based on the performance of the closed-loop system, while the robust stability and the robust performance is attained by an H∞ control.
A sufficient condition for the existence of a robust controller and the corresponding uncertainty bound is proposed in terms of matrix inequalities. Moreover, we show that those inequalities are reduced to be LMIs in some special cases. An application to a linear AC motor verifies the effectiveness of the proposed method.View full abstractDownload PDF (1687K) -
Takashi MISHIMA, Toru ASAI, Shinji HARA1996 Volume 32 Issue 1 Pages 45-54
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA stabilization problem is considered for linear time-invariant systems interpolated with two nominal plants, where the controller is an interpolation of stabilizing controllers for the nominal plants. So far, a linear function is used as the interpolation, and the linearity restricts the class of stabilizable plants. Employing a bilinear function as the interpolation leads to some enlargement of the freedom of the controller design, although the cost of the implementation remains to be almost same as the linear case. Therefore, we consider the stabilization problem, where both the plant and the controller are interpolated bilinearly.
In the SISO case, a necessary and sufficient condition for the stabilization of the interpolated plants is derived based on the Nevanlinna-Pick interpolation problem. Furthermore, an LMI description of the condition gives a method to decide a feasible bilinear interpolation. In the MIMO case, a sufficient condition is formed as a strict positive realness condition, and the design method is also proposed with LMI conditions in the state-space form. The effectiveness of the proposed methods is shown with some examples in both cases.View full abstractDownload PDF (1700K) -
Masafumi OKADA, Toshiharu SUGIE1996 Volume 32 Issue 1 Pages 55-61
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we give a new method of joint design of control and closed loop identification. Here we adopt the two-degree-of-freedom control system structure in order to obtain both good command response and satisfactory disturbance rejection property. Based on the prediction error method and appropriate choice of the identification objective, we show how to choose an weighting function for identification, which reflects the control objective and is suitable for two-degree-of-freedom control systems. In addition, we show a numerical example to demonstrate the effectiveness of the proposed method.View full abstractDownload PDF (1755K) -
Temperature Tracking Control of a Batch Reactor ProcessNoriaki SAKAMOTO, Masami MASUBUCHI, Seiichi KAWATA1996 Volume 32 Issue 1 Pages 62-68
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper shows that a control strategy using our fictitious set point is realized to the tracking control problem of a batch reactor process and that excellent control results have been obtained.
In this process, the reactor temperature is required to be raised by a fixed speed from the start-up to the desired temperature and to be kept at it. PID control was used for this object, but the reactor temperature showed frequent variation near the desired temperature and the heating steam and cooling water were wasted for this control. Conventional variable structure control is then considered to avoid this variation. However, computer simulation shows that the tracking control response can not be improved.
To reduce this frequent temperature variation and waste of energy, our control strategy is applied to this process after computer simulation. The experimental results are: that this method is quite effective as compared with PID control and conventional VSC laws and that 50% of the temperature variation and 45% of the consumption of steam and cooling water were decreased.View full abstractDownload PDF (1250K) -
Atsuhiko SHINTANI, Akira OHSUMI1996 Volume 32 Issue 1 Pages 69-77
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the feedback stabilization problems are investigated for a class of mechanically flexible cantilevered beams tipped with dynamic actuators on the free end. First, the mathematical models of the whole structure including the dynamic actuator are given by a couple of equations described by secondorder partial and ordinary differential equations. Secondly, based on such hybrid system model the feedback stabilization problem of the total system is investigated. To do this, a Lyapunov function is found from the total energy point-of-view, related to the actuator and the flexible structure parts. The conditions are derived for the feedback gains used in the dynamic actuator. Furthermore, some simulation results are presented. Finally, as the extension, the feedback stabilization problem is considered for the system which is subject to random disturbance.View full abstractDownload PDF (1468K) -
Atsushi KONNO, Masaru UCHIYAMA, Yutaka KITO, Mahito MURAKAMI1996 Volume 32 Issue 1 Pages 78-86
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn some spatial flexible arm manipulators, the structural vibration controllability is configuration-dependent. Therefore, the flexible arm manipulator might have some vibration uncontrollable configurations. In order to understand the physical interpretation of vibration uncontrollable configurations, we propose the “modal accessibility” concept which indicates how well the actuators can affect the structural vibration modes. The configuration in which all actuators cannot affect at least one of the vibration modes of the manipulator is vibration uncontrollable. Main contributions of the paper are the following two points: First, interesting structural vibration uncontrollable configurations are found within the 2-link 3-joint type manipulator's workspace. Some of these vibration uncontrollable configurations are shown with experimental results. Secondly, the modal accessibility index is introduced to indicate how well the corresponding vibration mode is controllable. Experimental results show that even in the controllable configurations, it becomes difficult to suppress some vibration modes if their modal accessibility indices are small.View full abstractDownload PDF (1529K) -
Shung-Hui HAO, Zi-Jiang YANG, Teruo TSUJI1996 Volume 32 Issue 1 Pages 87-96
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents an adaptive nonlinear control approach to a 4-point attraction magnetic levitation system using neural network. From the electromagnetic theory, we know the electromagnetic model of the magnetic levitation system is usually strongly nonlinear where coefficients change depending on the length of the air-gap, and the system can be represented in the normal form of a 4-input/4-output system based on some assumptions, where the nonlinear functions in the system are unknown. In this paper, we present a hybrid neural network using the generalized radial basis functions to model the nonlinear functions. The advantage of the hybrid neural network is that it is easy to choose the initial parameters based on the nominal values of the system paremeters, and the adaptive nonlinear controller can be designed to control the system to track a reference input. The parameters of the neural network are updated in an on-line manner according to an augmented tracking error. The results of the convergence analysis of the adaptive nonlinear control system are also shown. At last, experimental results are included to show the excellent performance of the designed adaptive nonlinear control system.View full abstractDownload PDF (1666K) -
Shogo TANAKA, Susumu KOUNO, Hiroaki HAYASHI1996 Volume 32 Issue 1 Pages 97-105
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSpreaders and lifters of cranes are usually controlled to stop at the same time when their trolleys are stopped. Despite the adequate control, however, the lifters have usually considerably large swings due to the free suspension of the lifters from the ceilings through pullies with two pair of wires. It is therefore important to measure the attitude of the lifters on-line in order to suppress the swings by second controls.
The authors previously proposed a maintenance-free automatic measurement and control system which measured the lifter's attitudes accurately and controlled the lifters to have no swings. But, the control system was available only after the trolleys were stopped, because the control system was constructed on the basis of the double pendulum model of the lifter system under no movement of trolleys.
The paper proposes a new on-line automatic measurement and control system which enables the lifters to stop at the same time when the trolleys are stopped. To realize it, the system uses a rotary-encoder and a tacho-generator on the trolley and a servo-type accelerometer on the lifter to extract a useful information on the trolley-lifter system.View full abstractDownload PDF (1663K) -
Kazushi SANADA, Ato KITAGAWA1996 Volume 32 Issue 1 Pages 106-113
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA proportional solenoid valve is applied to an automatic transmission to control shift operation. Its control system must be designed as a robust control system considering modeling error caused by a change in characteristics of the valve. In this study, a brake mechanism of an automatic transmission is considered as a plant. Two degree of freedom control of its rotating speed is studied in which modeling error due to a change in characteristics of a proportional solenoid valve is took into account. A feedback controller is designed based on μ synthesis in which a change in characteristics of the valve and variations of a frictional coefficient are considered as uncertainty of a nominal model. Introducing a feed-forward controller, a two degree of freedom control system is constructed. The control system is examined through experiment using a commercial proportional solenoid valve. Shift operation is precisely controlled by the control system under those fluctuating factors.View full abstractDownload PDF (1273K) -
Takahiro HANYU, Shigeki ABE, Michitaka KAMEYAMA, Tatsuo HIGUCHI1996 Volume 32 Issue 1 Pages 114-121
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a rule-based high-speed warning system for highly-safe cruise control in intelligent vehicles. All the dangerous states are defined in advance by rules which are represented by the conjunctions of condition entries, so that they can be detected by search operations between input information from sensor signals and rules. Moreover, a new content-addressable memory (CAM) is proposed for highly parallel search operations. Finally, it is demonstrated that the speed for search operations using the proposed CAM becomes twenty-five times faster than that using a conventional CAM.View full abstractDownload PDF (1538K) -
Kenji TERADA, Jun'ichi YAMAGUCHI, Masato NAKAJIMA1996 Volume 32 Issue 1 Pages 122-129
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the authors describe an automatic system for identifying individuals by the facial information obtained by using the three dimensional sensor. The authors have proposed a method for identification of human facial data obtained by using the fiber grating vision sensor which has been developed by the authors. But this method has two problems of the following; the strict restrictions on a subject person at the time for obtaining a facial data; and the coarse sampling range data obtained by using the fiber grating vision sensor. First, the authors propose a method for obtaining three dimensional facial data by using the fiber grating vision sensor. The present method is able to obtain the facial data without forcing the subject person to put his face at a fixed position and a fixed direction exactly. In this system, a mark on a floor and a mirror in front of the fiber grating vision sensor are used for the restrictions on the subject person. The useful data for the identification is obtained with forcing the subject person only to stand on the mark and to reflect his tip of nose in the mirror. Next, the authors propose a method for identifying the human faces accurately without being affected by the coarse sampling range data. In this system, to identify human faces, a multi-layered neural network is used in which the inputs are two component values of normal vector at data spot in the facial surface. To eliminate the effect of the coarse sampling range data is carried out by planing in learning process of the neural network. In this paper, the experiments using the experimental system are performed to demonstrate the efficacy of this system and the experimental results are shown.View full abstractDownload PDF (3412K) -
Yasuchika MORI, Hiroyuki AKIMOTO, Yasushi NAKAUCHI, Shin NYUDO1996 Volume 32 Issue 1 Pages 130-132
Published: January 31, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a new tuning method of the Generalized Minimum Variance (GMV) controller. Usually, in order to get the good performance of the closed-loop system, weighting coefficients of the cost function are tuned by trial and error. The proposed method uses PID gains (KP, KI, KD) as tuning parameters, therefore, tuning of the GMV controller becomes easy.View full abstractDownload PDF (359K)
- |<
- <
- 1
- >
- >|