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Volume 37, Issue 9
Displaying 1-15 of 15 articles from this issue
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Kozo OHTANI, Mitsuru BABA, Tadataka KONISHI2001 Volume 37 Issue 9 Pages 799-806
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we propose a new sensor which detects an incident position and angle of a light spot simultaneously. The sensor consists of two sensor arrays, an incident position detection component, and an incident angle detection component. The sensor is operated by means of the three main steps. First, the sensor receives the light spot in the sensor array unit. Next, in the incident position detection component, it detects the sensor element that generates the peak value by comparing the outputs of the sensor elements with the standard voltage, and then calculates the actual peak position with the analog interpolation by the second-order polynomial. Finally, in the incident angle detection component, an incident angle is calculated with the position information of the positions of the two sensor arrays by the analog operation. It was verified that it was the accuracy of 1.89% in the incident position and 0.48 degrees in the incident angle with the experiment by trial sensor system based on this technique.View full abstractDownload PDF (4240K) -
Katsumi HIRATA, Kimio SASAKI2001 Volume 37 Issue 9 Pages 807-814
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFor the purpose of developing refined devices for environmental recognition in autonomous mobile robots, a practical method for simultaneous estimation of 3D-position and velocity of a moving random acoustic source in near-field is proposed by using 4 fixed point-detectors. By using 3 pairs of estimated short time auto- and cross-spectra of signals detected simultaneously at 4 fixed point-detectors, information on ratios of relative compression or extension rates of the spectral patterns due to the Doppler effect, ratios of the amplitude attenuation of wave propagation and differences of wave propagation times between signals detected simultaneously are derived in such a manner that they are all independent of the shape of power spectrum of the source radiating random signal so as to be applicable to any moving acoustic source radiating a stationary random signal. Then, with an aid of geometric relations of signal detection, the source position and velocity in 3D-space are estimated by the least mean squared (LMS) method based on the information extracted above.
After the principle of the proposed estimation method and the required conditions being made clear, fundamental experiments are carried out to show the effectiveness of the method and make clear the influence of the detection noises on the final estimates. The results illustrate the effectiveness as well as fundamental characteristics of the proposed method under practical circumstances.View full abstractDownload PDF (2488K) -
State Variable Measurement for Transmission Time Delay System Using a Kalman Filter with Dual ModelsNaoyuki TAMARU, Joji YAMAGUCHI, Kazumasa KANEKO2001 Volume 37 Issue 9 Pages 815-820
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAiming to obtain current state variables of a mechanical system with a transmission time delay, we estimated state variables by using a Kalman filter. In order to increase the stability of the estimation system, we have proposed a novel Kalman filter with dual mathematical models. Experimental results for the state variable estimation show that unlike the conventional Kalman filter system, the estimation system with dual models is not apt to diverge even if there is longer transmission time delay. Moreover the estimation error in this system is smaller than one in the conventional single model by a factor of about three. That is to say, the Kalman filter with the dual models is precise and robust in the estimation process against the transmission time delay. Moreover this result is also confirmed by the computer simulation by obtaining the same results to the experiments.View full abstractDownload PDF (1597K) -
Relation between the Change in the Heart Rate and Sleep StagesTakashi WATANABE, Kajiro WATANABE2001 Volume 37 Issue 9 Pages 821-828
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe health condition could be determined by how deeply he or she sleep every night. Thus every one would like to monitor his sleep characteristics. But it is not popular. The expensiveness and the strong physical and mental monitoring stress by the conventional Rechtschaffen & Kales method using a polygraph prevent it to be popular. Development of sleep quality monitoring methods easy, kind and convenient to people is required.
The author presented an air mattress method to measure the human bio-information by a non-restrictive manner easy and kind to patients. If we can find some quantitative relations between the bio-information acquired by the air mattress sensor and the sleep stages judged from the polygraph data, the quality of sleep can be estimated easily and kindly.
In this study, we investigated the relations in the low (circadian), middle (ultradian) and high frequency ranges, respectively and found the following relations;
[low frequency] The gradient of sleep stages is strongly co-related with that of heart rate.
[middle frequency] The sleep stages and the heart rate have the strong co-relation.
[high frequency] The Non-REM oscillation can be estimated from the heart rate fluctuation.
From these results, we built a simple mathematical model from which the sleep stages can be estimated only by the heart rate data acquired from the air mattress sensor.View full abstractDownload PDF (2752K) -
Hiroki YAMAMOTO, Nobuharu AOSHIMA2001 Volume 37 Issue 9 Pages 829-834
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDealing with two dimensional acceleration signal as a complex signal on Gaussian plane, the time characteristics of the acceleration vector can be analyzed by Fourier transform on complex form. The spectrum calculated with this method is useful to understand the physical image of two dimensional movements about the acceleration. Therefore, for the quantitative comparison and evaluation of the behavior of two dimensional acceleration data, some evaluate functions and index parameters based on the complex spectrum are proposed. And analyses of vehicle crash acceleration data are described to show the effectiveness.View full abstractDownload PDF (1476K) -
Ichiro JIKUYA, Hidenori KIMURA2001 Volume 37 Issue 9 Pages 835-841
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe consider a model set in the dual chain-scattering framework. Given a rational transfer function matrix which we call a generator, a model set is defined by the dual Homographic transformation of the generator and the norm-bounded linear time-invariant uncertainty. We show that the continuity of the dual Homographic transformation with respect to the graph topology is necessary for robust stabilization of two class of controllers; LTI controller and NLTV controller. Moreover, for each class of controller, certain conditions must be included.View full abstractDownload PDF (1305K) -
Takao HINAMOTO, Shunsuke YAMAMOTO2001 Volume 37 Issue 9 Pages 842-848
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers the problem of designing error feedback coefficients that reduce the output roundoff noise in the closed-loop system with a state-estimate feedback controller implemented by fixed-point arithmetic subject to l2 scaling. First, we describe the closed-loop system with a state-estimate feedback controller. Next, after incorporating an error feedback into the state-estimate feedback controller, the optimal closed-form solutions of error feedback coefficients is presented to minimize the output roundoff noise of the closed-loop system. Then, a straightforward method is developed to determine the error feedback diagonal matrix that reduces the output roundoff noise of the closed-loop system, when a state-estimate feedback controller is realized in the input-balanced form. Moreover, under the assumption that all the diagonal elements are equal, some conditions are explored which provide a smaller output roundoff noise than that of the optimal state-estimate feedback controller realization with minimum output roundoff noise, constructed by the appropriate choice of the coordinate transformation. Finally, a numerical example is given to illustrate the utility of the proposed technique.View full abstractDownload PDF (1442K) -
Toshiharu SUGIE, Hiroyuki YAMAMOTO2001 Volume 37 Issue 9 Pages 849-855
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a method to generate modified reference signals for closed loop systems so as not to violate the input and state constraints of the plants. In particular, improvement of the output response is taken into account explicitly subject to the given constraints, and the method is computationally efficient because of LMI formulae. The effectiveness of the proposed method is evaluated by simulation.View full abstractDownload PDF (1657K) -
Fujio IKEDA, Seiichi KAWATA, Atsushi WATANABE2001 Volume 37 Issue 9 Pages 856-861
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers an optimal control problem for linear fractional differential systems which are described in terms of fractional order derivatives of state variables. The optimal feedback gain matrix is derived by using Lyapunov equation and Lagrange multiplier method. It must satisfy simultaneous matrix equations which are solved by iterative calculations for convergence.
A numerical example is carried out for the optimal regulator design of a viscoelastic damper system which is often said to be a good example of a fractional differential system.View full abstractDownload PDF (1449K) -
Kiyotaka SHIMIZU, Nao MISHIMA2001 Volume 37 Issue 9 Pages 862-871
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with a performance based nonlinear servo controller. The aim of usual nonlinear servomechanism problem was to asymptotically stabilize the closed loop system, i.e., to let the error converge to zero. Here we try to improve the convergence speed by designing a servo controller so as to decrease a performance function like the squared error momently. At the same time, we propose a new method applying neural network to solve approximately the nonlinear output regulation equation which is necessary to be solved as designing the nonlinear servo controller. The effectiveness of the proposed method was confirmed with simulation results for TORA model.View full abstractDownload PDF (1976K) -
Yasuhide KOBAYASHI, Tsuyoshi OKITA, Shinichi TANAKA2001 Volume 37 Issue 9 Pages 872-879
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe present a new identification algorithm for parameter estimation of time-varying linear discrete-time systems. The change of environment of the system might cause system parameter fluctuations. As these fluctuations are unknown, the system parameters can not be represented by a specific function. The artificial neural networks which have the ability to learn complex nonlinear relationships, are applied to represent the fluctuations of system parameters.
These system parameters are estimated by optimizing the nonlinear objective function which is the total error of the system and the model. The optimization problem of the objective function results in the learning of the interconnection weights of the network. Some techniques are required for setting appropriate initial points in optimization, because there is many unfeasible local minimum points. To find the globally optimal set of weights, the weights that result from training the more simplified function are used to initialize the networks.
Furthermore, it is verified by simulation that the effectiveness of the proposed method can be applied to the system with unknown parameters.View full abstractDownload PDF (1349K) -
Doohyung KIM, Masaru UCHIYAMA2001 Volume 37 Issue 9 Pages 880-885
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents the execution of very fast and complicated tasks with a high-speed and accurate parallel robot, named HEXA. We propose a unified motion, force and compliance control scheme which does not use any force/torque sensors, but exploits actuator back-drivability. It is a well-known fact that with the back-drivability in the actuator, the weight and cost of the force control system is reduced. The motivation behind this work is to exhibit the usefulness of the versatile HEXA mechanism for applications in industry. Different experiments for complex and fast tasks, for example, sequential peg-in-hole insertions on an inclinded table, crank-turning, tdeburring and composite tasks have been performed using this control system.View full abstractDownload PDF (3703K) -
Fujio TORIUMI, Li CAO, Shinji OHYAMA, Akira KOBAYASHI2001 Volume 37 Issue 9 Pages 886-892
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSBand function model paired comparison (BMPC) method is effective for scaling of ambiguity quantity in the case such as sensory evaluation. The solution algorithm for BMPC method needs a large memory capacity and spents a lot of time. This reason is that the conventional method didn't utilize the functional relation between edge vectors and hyper planes on the solution domain. In this paper, we consider some natures of the inequalities to obtain solution domain and discuss about the edge vectors expressing solution domain. And we proposed the new effective algorithm to renewal solution domain based on the revealed natures of the inequalities. The new algorithm is examined and improved calculational performance are shown in the point of view of calculation time and memory capacities.View full abstractDownload PDF (1584K) -
Jiangming MAO, Kotaro HIRASAWA, Jinglu HU, Junichi MURATA2001 Volume 37 Issue 9 Pages 893-901
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSEvolutionary Algorithms are often well-suited for optimization problems. Since mid 1980's, the interest in multi-objective problems has been expanding rapidly. Various evolutionary algorithms for multiobjective problems have been developed which are capable of searching for multiple solutions concurrently in a single run. In this paper, we propose a new genetic symbiosis algorithm (GSA) for multiobjective optimization problems (MOP) based on the symbiotic concept found widely in ecosystems. In the proposed GSA for MOP, a set of symbiotic parameters are introduced to modify the fitness of individuals used for reproduction so as to obtain a variety of Pareto solutions corresponding to user's demands. The symbiotic parameters are trained by minimizing a user defined criterion function. Several numerical simulations are carried out to demonstrate the effectiveness of the proposed GSA.View full abstractDownload PDF (1824K) -
Yoshiaki MATSUMOTO, Kentaro TSUCHIMOTO, Shogo TANAKA2001 Volume 37 Issue 9 Pages 902-904
Published: September 30, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe previously proposed a measurement system of heartbeat and respiration periods using a phonocardiographic (PCG) sensor set on a water-mat or an air-mat. The system could measure not only the average periods but also the instantaneous ones of heartbeat and respiration when subjects were sleeping in beds without snoring.
This paper extends the system to enable the measurement of heartbeat and respiration periods even when subjects are snoring. Precisely speaking, the system measures the average heartbeat period and instantaneous respiration period by separating the output of the PCG sensor into heartbeat and snoring components.View full abstractDownload PDF (531K)
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