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Volume 7 (1971)
- Issue 6 Pages 499-
- Issue 5 Pages 393-
- Issue 4 Pages 295-
- Issue 3 Pages 197-
- Issue 2 Pages 99-
- Issue 1 Pages 1-
Volume 7, Issue 2
Displaying 1-13 of 13 articles from this issue
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Yutaka OHBUCHI, Taro URABE, Yoshifumi SAKURAI1971 Volume 7 Issue 2 Pages 99-105
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn adaptive control systems such as a process control system, a learning system or an automatic designing device, analog memory elements with multiplying function are required. Such an analog memory element with multiplying function was realized by using a toroidal core with rectangular hysteresis loop. Having the core partially magnetized by voltage pulses along the easy direction, and applying two sinusoidal magnetic fields with frequencies of 1/7MHz and 1/8MHz, a beat frequency component (1/56MHz) of the induced voltages is detected as an output signal corresponding to the stored flux level. Two kinds of elements were obtaind, depending whether the magnetic field was applied along the easy direction or along the hard direction. The one obtained by applying the field along the hard direction provides a beat frequency output voltage VΔ proportional to the algebraic product of two exciting currents (AC) I1, I2 and stored flux φ. The range of inputs I1, I2 and φ is 0∼0.5A, 0∼0.5A and -1.5×10-3∼+1.5×10-3volt-second, respectively. The accuracy (Verror/Vmax) with respect to I1, I2 and φ is 3, 3 and 7%, respectively. The inditial response time with respect to I1, I2 and φ is 2.8ms. In addition to the multiplying function, the analog memory element shows the advantage of being a simplified filter, and of having no mismatching of the two cores and etc., in comparison with ordinary magnetic analog memory elements. The element shows a possibility to realize a Two Dimensional Read-Out system.View full abstractDownload PDF (2110K) -
Tsugumasa SUTO, Akira TOZUNE1971 Volume 7 Issue 2 Pages 106-112
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn servo-mechanism, the alternating torque of 2-phase sevro-motor causes undesirable problems.
In this paper, the operation of a 2-phase servomotor under an unbalanced voltage supply is analysed by means of the elementary method and the 2-phase symmetrical component method.
In studying and comparing the results obtained by the two methods, an equation is derived to calculate the alternating torque by using the equivalent circuit parameters.
The equation is simplified by introducing the specific relation among the equivalent circuit parameters of 2-phase servomotor.
An experiment was performed with the test 2-phase servomotor.
The amplitude of acceleration was recorded by a 2-phase induction generator type accelerometer. The alternating torque was calculated from the recorded data to be compared with the calculation by using the above equation. The agreement was satisfactory.View full abstractDownload PDF (732K) -
Tatsuo HIGUCHI1971 Volume 7 Issue 2 Pages 113-121
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe authors have already reported on an analysis of a single core balanced output magnetic amplifier proposed by Darling (Darling's circuit).
In this paper, first, the experimental results obtained on the zero drift caused by the fluctuations in the AC supply voltage and frequency, the ambient temperature and so on, are compared with the calculated results on the basis of an analysis of Darling's circuit. When these environmental conditions are stabilized well, it is experimentally recognized that the core noise or the zero-output noise caused by the fluctuations of the amount of flux in the dynamic hysteresis loop becomes detectable. The minimum allowable input level of Darling's circuit is determined by this core noise. The magnitude of core noise in Supermalloy is about equivalent to the magnitude of zero drift that is caused by the change in the ambient temperature of core from 20 to 30°C, or of diode from 20 to 21°C. Lastly, experimental studies on the core noise are performed, so that the various characteristics of core noise are made clear.View full abstractDownload PDF (1156K) -
Takeshi KAWANISHI, Hisao MARUYAMA1971 Volume 7 Issue 2 Pages 122-128
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe method of measuring a circuit's transfer function described here is based upon a test which employs an impulse function called the delta function. Since the delta function, which is a zero width spike of unit energy content, has frequency components of constant amplitude at all frequencies, the circuit output response is uniquely determined by the circuit transfer function.
In practice, although a true impulse can not be generated physically, a rectangular pulse with a very narrow pulse width (much less than the significant time constant of the system) usually provides a suitable approximation. The rectangular pulse function is a simple and convenient prototype for the impulse function but it is a discontinuous function. In certain problems of interest, it is desirable to use a prototype which possesses derivatives. Further, it is desirable to define the impulse function to be an even function of its argument. One such function is the gaussian pulse function. The gaussian pulse function hence satisfies the defining equation of the unit impulse function in the limit when σ, the standard deviation, approaches zero. Furthermore, the method for approximating the impulse response by the gaussian impulse can be easily extended to the random process by means of the auto- and cross-correlation functions of the process input and output signals.
The present paper is divided into two main parts. The first part is devoted to the development of a method of generating gaussian signal by an analog computer. The second part is concerned with the method to measure the parameter of the transfer function derived from the moment of the output response of the gaussian signal. It has become clear from the experimental results that this method is effective in finding the dynamic characteristics of adaptive control systems, because the transfer function can be estimated by the simple operation with sufficient accuracy.View full abstractDownload PDF (2916K) -
Identification of Nonlinear Dynamic Systems without Self-Regulation Using Volterra Functional SeriesKatsuhiko FUJII, Kazuo NAKAO1971 Volume 7 Issue 2 Pages 129-136
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSInput-output relation of a nonlinear dynamic system can generally be described by Volterra functional series. The Volterra functional series is a generalization of the convolution integral conventionally used in linear systems. However, when the system is not self-regulatory, the integration interval of the functionals must be infinite and thus these functionals are not suitable for practical use. Therefore, in this paper, the Volterra functional series are transformed into those with finite integration interval. The Volterra kernels in the transformed series are constructed so as to include the effect of the unknown input signal in the past. Application of deterministic signals to both the system and the transformed Volterra functional series model and evaluation of the responses lead to the determination of Volterra kernels which represent the dynamic characteristics of the system.
This method can be applied to the system whose topological structure is not a priori known. The degree of approximation of this method can be arbitrarily specified. This method is also valid for the systems with self-regulation.View full abstractDownload PDF (893K) -
Taro TAJIMA1971 Volume 7 Issue 2 Pages 137-142
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe large scale production of the temperature compensated zener diode (TCZD) whose temp. coeff. is as small as 0.002%/deg is difficult and costly.
The methods so far proposed are inefficient, laborious and time-consuming.
In order to overcome these difficulties, we analyzed this problem from the statistical point of view, and found basic data to produce TCZD with good yield.
After general consideration we suggested a new type TCZD which contains two chips. The chip is recently reported by us and consists of several pn-junctions.
In this report we used the chip whose size is 500μ×500μ. After the sampling test we connected those pn-junctions together and constructed the TCZD.
A summary of the results in the small scale production is shown below.
The percentage of the TCZD, whose temp. coeff. is smaller than 0.002%/deg, was 80∼90% in each of the four lots.View full abstractDownload PDF (2401K) -
Hiroshi KAWARADA1971 Volume 7 Issue 2 Pages 143-149
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSD.D.A. (Digital Differential Analyzer) has a useful high performance for many applications, especially for numerical control. It can, for example, generate any outline curves of a part by concatinating solution curves of various differential equations.
Owing to several reasons, however, the D.D.A. 's high performance has never been fully utilized in practice. One of the most serious of these reasons is the difficulty in estimating accurately the error in D.D.A. computation.
This paper presents a new and generalized method of computation error analysis in solving any ordinary linear differential equations with constant coefficients. In this method, each digital integrator is replaced equivalently by an ideal analogue integrator with an error function E(t) added to its output. Then, the computation error is obtained as a solution of a linear differential equation having some forcing function. An explicit representation of the computation error is given, from which the upper and lower bounds of the computation error can be estimated by easy calculations.
Some examples show that such estimation of error is sufficiently accurate and useful for many applications of D.D.A.
One of the most important results of this paper is that the computation error in solving a linear differential equation decreases proportionally with the size of the unit increment in the digital integration. From this fact it is shown that any linear differential equation can be solved with the computation error of at most one unit of increment by a special programming.View full abstractDownload PDF (823K) -
Kokichi NITTA, Hiroshi OKITSU, Takayuki SUZUKI, Yosuke KINOUCHI, Shige ...1971 Volume 7 Issue 2 Pages 150-157
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, the power amplifiers using semi-conductor switching elements are employed widely in industries, because they have more advantages than the conventional rotating amplifier, magnetic amplifier, etc. In such power amplifiers, the power converters with switching operation (chopper, inverter, converter and cycloconverter) can be incorporated so that the desirable amplifying characteristics may be achieved by an adequate control of switching.
In this paper, we deal with the bridge type power amplifier, because this is simple in the construction and is often used for the power amplification. For the purpose of linear amplification, we study the operation time and the logical functions of the switches when the source voltage in this amplifier is an arbitrary function of time.
Moreover, an output filteris necessary to obtain the desirable wave form of the output voltage, therefore, we analyze the wave form of the instantaneous output voltage and examine the results. We can obtain the design specifications of the filter from these results.
As stated above, the purpose of this paper is to establish a general theory of amplification by assuming that the source voltage is a time variable.View full abstractDownload PDF (980K) -
Kazuyuki HOTTA, Tatsuro MATSUI, Nobutoshi TANAKA, Koichi IINOYA1971 Volume 7 Issue 2 Pages 158-165
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn many of the design and control problems, it is often felt important for the mathematical model of the process to have more accuracy in its statics than in dynamics.
As to the statics, however, there has been accumulated a great deal of work and it is usually safe to assume that some sort of static model, though often highly nonlinear, is available for most of the processes involved. On the other hand, the effort of process-dynamicists has so far been focussed mainly on obtaining linear models by using perturbation method. The performance of the linear models is naturally poor, especially in the prediction of the static characteristics, when large state changes are involved.
The purpose of the present study is to combine the nonlinear static model with the linear dynamic model and obtain an improved model which describes the process statics exactly and the dynamics approximately for all kinds of inputs.
First, three basic models are proposed. They are so selected that their statics for all inputs and the dynamics for samll inputs are exact. Then techniques to modify or combine these basic models are introduced enabling us to obtain a model with improved dynamic behavior for all kinds of inputs. An example is also shown illustrate the model forming process.View full abstractDownload PDF (961K) -
Hajime MAEDA1971 Volume 7 Issue 2 Pages 166-171
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt has been shown that in the case of time-invariant finite-dimensional linear systems, the controllability and the pole assignability are equivalent, in the sense that arbitrary closed pole locations can be achieved by the state-variable feedback if and only if the open-loop system is controllable.
The present paper considers a class of nonlinear systems which are constructed by a cascade connection of a nonlinear block and a linear time-invariant finite-dimensional system, and shows that the specified degree of stability can be achieved by the state-variable feedback if and only if the open-loop linear subsystem is controllable.
It is also shown that the desired feedback matrix can be determined (not uniquely) by solving a quadratic matrix equation. As an application of the result, the paper considers a stability problem by means of output feedback and gives a unified design procedure of a compensator which achieves the specified degree of stability.View full abstractDownload PDF (730K) -
Kunihiko ICHIKAWA1971 Volume 7 Issue 2 Pages 172-180
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMost researches on the optimal control of time delay system in the past were concerned with the necessary condition for optimal control, that is, the maximum principle. The maximum principle, however, is not generally so effective for finding the optimal control, and the direct computing method is preferred. Almost all of the direct methods resort to the gradient function, and it is not too much to say that the problem for finding optimal control is half solved once the means for computing the gradient function have come to hand.
First, by making the concept of the state of time delay system clear, it is recognized that the time delay system is essentially a distributed parameter system. Then, the dynamics of the time delay system are described in the form of partial differential equation together with its boundary condition. After that, the gradient function is derived. The procedure of derivation is outlined below.
The transition matrix is defined first, and then the gradient function is obtained in terms of transition matrix. The calculation of the transition matrix, however, is extremely complicated, though not impossible in principle, so the expression is not suited for practical use. By introducing a suitable costate, the gradient function is rewritten in terms of the costate. Taking advantage of the particular property of the transition matrix, the partial differential equation and the boundary condition to be satisfied by the costate are derived. The costate is easily computed by integrating numerically the costate system with respect to backward time. Thus, the latter expression of gradient function is very convenient for practical use.View full abstractDownload PDF (1102K) -
Aisuke KATAYAMA1971 Volume 7 Issue 2 Pages 181-189
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSensitivity in the optimal control of the plant with varying parameters is treated. The curious results of the sensitivity criteria derived by Pagurek and Witensenhausen are inquired and extended to the derivation of the relative sensitivity which is developed in the paper.
The conditions of minimizing the proposed relative sensitivity are given by equating the differentials of the optimal and suboptimal control laws with respect to the parameter regarded as a variable around the nominal value. The result is used to obtain the suboptimal control system having feedback loops.View full abstractDownload PDF (951K) -
Etsujiro SHIMEMURA, Kinji MORI1971 Volume 7 Issue 2 Pages 190-195
Published: April 30, 1971
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe optimal control problem of a linear system with time-delay for a quadratic performance index is discussed.
The problem is formulated as that of a coupled system of a lumped parameter subsystem and a distributed parameter subsystem which corresponds to a group of time-delay elements.
The optimal control is derived by applying the principle of optimality, and is given in a form of a linear combination of states of the both subsystems.
In other words, the optimal control is realized by a linear feedback of a present value x(t) and a history x(τ), t-θ(t)≤τ<t, of the state of the lumped parameter subsystem. Furthermore, it is shown that the optimal feedback gains are the solutions of the Riccati type ordinary and partial differential equations.View full abstractDownload PDF (659K)
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