All issues
Volume 27, Issue 9
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Kyung-Young JHANG, Takashi TSUCHIYA, Takuso SATO1991 Volume 27 Issue 9 Pages 973-981
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, a new method to detect the trace of a vehicle's movement by using four optical line detectors and fourth order crosscorrelation analysis is proposed.
In this method, during the movement of the vehicle, the line detectors observe the relatively moving road as the intensity variation of the light reflected from the road on the line of each detector. On the first line detector, however, properly separated two windows are provided so that it detects only the flow of the road pattern passing through these two windows. Then the time delays of such pattern flows between the first detector and the others are estimated by using the fourth-order crosscorrelation analysis of the detected signals, and the parameters about the relative movement of the road pattern, say, the velocity and the radius of curvature are derived by combining the estimated delays and the geometry of the detectors' arrangement.
These parameters identify the instantaneous trace of the vehicle as the approximated circular arc, hence, the desired trace of the vehicle can be reconstructed by connecting sequentially these instantaneous traces.
To confirm the validity of this method, an actual measurement system was constructed and preliminary experiments were carried out by moving the photographs of the real road as the model of moving rough surfaces. The results showed clearly the usefulness of the proposed system.View full abstractDownload PDF (1810K) -
Theoretical Analysis and Numerical SimulationShigeru ANDO1991 Volume 27 Issue 9 Pages 982-989
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, nonlinear image operators for extracting functional feature of spatial grayness variation are proposed. First, we show that a degree of degeneration of an extended gradient covariance matrix between grayness f and its gradient fx, fy indicates a degree of fit of the variations to an exponential functional shape. Then, in order to express the degeneration independently on contrast and resolution, we derive several dimensionless and normalized equations from inequalities between second and third order eigenvalue polynomials of the matrix. After adding noise suppressing capability to the equation, we obtain four types of feature operator triplets Ri, Pi, Qi (i=1, 2, 3, 4) which discriminate 1) significant variations, 2) exponential variations, and 3) anti-exponential variations of varying degrees. By analysing maximal conditions of Qi under which grayness loses completely the above defined exponentiality, we show Qi functions as image structure finders which respond in selective but scale/orientation insensitive manners to homogeneous and inhomogeneous peaks/dips/saddles, and flat and inclined ridges/valleys. Those functions of the proposed operators are confirmed with several computer simulations under ideal and noisy conditions.View full abstractDownload PDF (1185K) -
Ryoji KAWATANI, Takao FUJII, Hidenori KIMURA1991 Volume 27 Issue 9 Pages 990-995
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the physical structure of the H∞ controllers (especially, the central controller) for the so-called four block and one block standard problems, which have been derived by the Conjugation method, is investigated based on the differential game theory. As the results of that, it makes clear that H∞ controller has not only the mechanism of full state observer, but also that of reasonable disturbance estimator. The former is well-known fact, but the latter is an important structure to understand H∞ controllers. The disturbance estimated in the controller is used to diminish the effect of exogenous input on the controlled output. Furthermore, from the view of this feedforward structure, the essential difference between four block and one block problem also makes clear.View full abstractDownload PDF (719K) -
Zenta IWAI, Kazuhiko TSUTSUI, Katsuya KAI1991 Volume 27 Issue 9 Pages 996-1001
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, simple adaptive control (SAC) has become of general interest in regard to its simple but robust adaptive control structure. However, the application of SAC was confined to the plant which satisfies the almost strictly positive real (ASPR) condition. This paper deals with this problem and it is proved that the use of parallel feedforward compensation makes it possible to apply SAC to non-ASPR plants under usual assumptions in the design of robust adaptive control system. Since the SAC algorithm does not depend on the degree of the plant, it becomes robust even if the plant contains unmodeled dynamics. This fact is confirmed by applying SAC with parallel feedforward compensation to the well-known Rohrs' example.View full abstractDownload PDF (795K) -
SHUMING Chen, Yoh YONEZAWA, Yukio NISHIMURA1991 Volume 27 Issue 9 Pages 1002-1008
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSResently various design methods of MRACS (Model Reference Adaptive Control System) have been proposed for plant with deterministic disturbance. But in order to apply MRACS to practical systems, it is desirable that MRACS can also be valid for undeterministic disturbance. For bounded disturbance, there have existed an stable adaptive control method which assures the output error of plant to be bounded by using a dead-zone, but this method cannot make the output error tend to zero. Therefore the method is not an active way in the sence of decreasing the effect of disturbance.
This paper deals with a design method of MRACS for discrete plant with unknown parameters in the presence of disturbances. The disturbances are assumed to be: (1) polynomial of time, or (2) periodic, or (3) varying slowly, or (4) the linear combination of (1), (2), (3). By introducing a disturbance compensator, the MRACS is composed with no increasing of numbers of parameter needed to adjust. It is possible to make the output error tend to asymptotically zero with time for the cases (1) and (2). For the cases (3) and (4), it is possible to reduce the effect of disturbances to a small value. The stability of this MRACS, and the boundedness of all signals in the system are proved if the plant is minimum phase and the disturbance is bounded. The effectiveness of this proposed method is illustrated by computer simulations.View full abstractDownload PDF (811K) -
Koji YAMADA, Tatsuya SUZUKI, Shigeru OKUMA1991 Volume 27 Issue 9 Pages 1009-1017
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA contact motion of a robotic manipulator to a workpiece is a fundamental operation which occurs frequently. The contact motion is a very short time phenomenon and a so-called impact force arises. If we use only a feedback control scheme, it is difficult to realize a desirable contact motion. In this paper, a new control method of the contact motion by a learning control is proposed. The learning control is based on an iterative operation, and is one of the feed-forward controls which do not need precise values of system parameters or a model of the impact force. Therefore it is useful for the contact motion control. Proposed learning controller has two features as follows. Firstly, it observes an input signals and output signals at the different period so as to improve a transient response of a system. Secondly, it can learn an initial state of the system, which includes an approaching velocity of the manipulator. By learning the approaching velocity, an fast contact motion can be achieved, because the magnitude of impact force depends on the approaching velocity. Simulation results are shown to verify an effectiveness of the proposed method.View full abstractDownload PDF (1155K) -
Shuichi ADACHI, Takashi KIDA, Yasuo TAKAGI, Yasuchika MORI1991 Volume 27 Issue 9 Pages 1018-1024
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFor many years, the importance of active feedback control of large space structure (LSS) have been widely recognized. This paper presents results on studying the attitude control problem for an LSS typified by the ETSVI (Engineering Test Satellite-VI) spececraft. The attitude control system based on the statefeedback control is proposed. The control law is designed by using the turn over design method. This method, which locates closedloop poles to be in a specified region, has good properties of the optimal regulator and the pole-placement method, so it has excellent vibration supression capability. Moreover, the proposed control method has some desirable robustness properties against modeling uncertainties such as inaccurate identification of natural frequencies and damping ratio and so on. The purpose of this paper is to show the efficiency of the proposed control method by a ground-based test model. The ground-based test model simulates the attitude motion around roll-axis by using a single-axis air-table. The experimental results indicated that the turn-over design method has great promise for used in LSSs.View full abstractDownload PDF (900K) -
Hidemine OHNO, Kensuke HASEGAWA1991 Volume 27 Issue 9 Pages 1025-1033
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe authors propose a methodology to transform the C/E system to the Mark Flow Graph (MFG) equivalent in the meaning of occurrence series of events.
It is well known that the C/E system is used effectively to represent the specification of the complex sequential control systems having the parallelism and conflict. On the other hand, the MFG was proposed as the extended C/E system to precisely represent the control algorithm. Therefore, it is necessary to convert the C/E system to the corresponding MFG as a control algorithm suitable to controllers to be adopted. In this process, no matter which kind of control algorithms (the Petri net type or the ladder type) are to be deduced, to eliminate the dummy conditions in the C/E system, is necessary to simplify the algorithm and also to deduced the hard-wired control systems.
For this purpose, replacing all conditions in the C/E system to logic variables (condition variables), the condition logic equations based on the minimum support are introduced to obtain dummy conditions as the logic functions of the other conditions. Substituting them to the event enabling equations, the dummy conditions are eliminated from the original C/E system and the equivalent MFG is obtained. Examples reveal the straightforward procedure of the transformation of the C/E system to the MFG.View full abstractDownload PDF (1094K) -
Hiroyuki KAJIWARA1991 Volume 27 Issue 9 Pages 1055-1057
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSJ.R. Bar-On, et al. presented a computation method of phase margins for multivariable feedback systems, solving a minimization problem under two constraints by Newton-Rapson technique. This note shows that their repetitive method can be revised to an new algebraic method by reducing the two constraints to only one.View full abstractDownload PDF (236K) -
Tielong SHEN, Katsutoshi TAMURA1991 Volume 27 Issue 9 Pages 1058-1060
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper a necessary and sufficient condition is presented for existence of a kind of H∞ robust sub-optimal controller. It is shown that this H∞ robust sub-optimal controller can be obtained by solving a Riccati inequality.View full abstractDownload PDF (368K) -
Tomohiro KUBO1991 Volume 27 Issue 9 Pages 1061-1063
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA method to construct a decentralized control law for large scale systems, which consist of subsystems with time-delay in states, is proposed. With this method, the closed loop poles of the overall system are located in a specified half-plane.View full abstractDownload PDF (295K) -
Tatsuya SUZUKI, Shigeru OKUMA1991 Volume 27 Issue 9 Pages 1064-1066
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe study a linear learning control system whose input number is less than output number. Based on a geometrical consideration of an error transition function matrix, a new learning stability condition is derived. Moreover, an error convergence value in that case is shown.View full abstractDownload PDF (437K) -
Hideo ISHIHARA, Seiji KOBAYASHI1991 Volume 27 Issue 9 Pages 1067-1069
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, an adaptive and learning control scheme for a class of unknown nonlinear systems, called “variable transform reset”, is proposed. Experimental results for a nonlinear arm show the effectiveness of the proposed scheme.View full abstractDownload PDF (336K) -
Zhi-wei LUO, Koji ITO, Masami ITO, Atsuo KATO1991 Volume 27 Issue 9 Pages 1070-1072
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper studies on a bilinear model for joint impedance control in contact tasks. It is proved that in order for robot to operate on dynamic objects smoothly without any oscillation, adjustment of the antagonist coactivation is useful.View full abstractDownload PDF (436K) -
Takashi KIDA, Isao YAMAGUCHI1991 Volume 27 Issue 9 Pages 1073-1075
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSProposed herein is a linearization method of spacecraft nonlinear motion in a rigorous sense. We intend to make existing linear controlller design tools applicable to nonlinear space systems by using it. A simple numerical example is demonstrated.View full abstractDownload PDF (338K) -
Takashi KIDA, Keiji KOMATSU, Masao IKEDA1991 Volume 27 Issue 9 Pages 1076-1078
Published: September 30, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTwo algorithms of obtaining the transmission zeros of collocated LSS system modelled by the FEM method are proposed. Their physical meanings are investigated and a numerical example is demonstrated to verify the results.View full abstractDownload PDF (365K)
- |<
- <
- 1
- >
- >|