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Volume 1 (1965)
- Issue 4 Pages 291-
- Issue 3 Pages 199-
- Issue 2 Pages 93-
- Issue 1 Pages 1-
Volume 1, Issue 2
Displaying 1-13 of 13 articles from this issue
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Kageo AKIZUKI1965 Volume 1 Issue 2 Pages 93-102
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe paper describes how to synthesize a servomechanism with a controlled process whose transfer function is 1/s(s+1), in order to obtain good response. Desired input signal to the system is assumed Gaussian stationary random with the power spectrum density P/(Ts2ω2+1). Saturation of manipulated variable is taken into consideration using Booton's linearization.
Under these conditions, following results are found.
(1) When the transfer function of the controller is simple gain K, it is shown that the larger value of K makes the smaller mean square error, if Ts>1.
(2) Transfer function of the optimum linear controller that minimizes mean square error is determined by means of the linearization.
(3) Neglecting small parameters contained above transfer function, the optimum transfer function of the controller is found as (s+1)/(αs+1). The system with this optimum controller shows good response.View full abstractDownload PDF (1140K) -
Takuso SATO, Hiroshi KAWARADA1965 Volume 1 Issue 2 Pages 103-106,153
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the preceding paper a new correlator using random-voltage-method was proposed. In this paper the generalized random-voltage-method, in which noise having any density distribution other than uniform distribution is used as the random voltage, is presented and examined. Then a new method of generating the excellent random voltage with uniform density distribution is proposed. Finally, three kindes of errors in the measurement of the correlation function using the random voltage method are analyzed and estimated. This estimation of errors gives the necessary conditions in the measurement of the correlation function of given time series.View full abstractDownload PDF (518K) -
Vertical Pointer ShaftTamotsu FUKUMOTO, Michiharu HORIUCHI1965 Volume 1 Issue 2 Pages 107-113
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMost instruments get out of order under mechanical vibration. Hair springs of moving elements often resonate with axial vibration, resulting in zero shift of meters (-10∼-15deg. for example). Pointer shafts get into relative hopping motions with thrust bearings and are rotated by horizontal component of vibration. In the latter case, value of instrumental error easily varies depending on sort and dimensions of bearings, and vibrating conditions, and constant of control spring. With normal thrust bearings of slidng type, this value becomes very large up to about 100deg., sometimes positive and other times negative. It is regrettable that the indicated value generally can not be corrected.View full abstractDownload PDF (881K) -
(Horizontal Pointer Shaft)Tamotsu FUKUMOTO, Michiharu HORIUCHI1965 Volume 1 Issue 2 Pages 114-121
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSPresented in the previous paper is the rotation of vertical pointer shaft under mechanical vibration. This paper reports that under the same condition, not only vertical pointer shaft but also horizontal one rotates likewise and causes a significant instrumental error. Horizontal pointer shaft gets into a relative hopping motion with its radial bearings and rotates, for example, two steps for each one cycle of vibration. Instrumental error is apt to become so large, reaching about 90 degrees. This phenomenon relates to sort and dimensions of bearings and vibrating condition. No pointer shaft, if it has sliding bearings, can be free from instrumental error of this kind.View full abstractDownload PDF (973K) -
(The Best Pointer Shaft)Tamotsu FUKUMOTO, Michiharu HORIUCHI1965 Volume 1 Issue 2 Pages 122-128
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt has been reported that the pointer shaft having sliding bearings rotates under mechanical vibration. In this paper, better bearings for the shaft are given and furthermore, why they are better are explained theoretically and experimentally. Although jewel-pivot bearings are better than sliding ones, the former causes remarkable instrumental error, 10 to 15 degrees for example. When ball bearings are used with pointer shaft, no unnegligible error is observed. Ball bearings are the best for the instruments under vibration. A spannbanded pointer shows no instrumental error, too, but it often resonates with low frequency vibration across the band.View full abstractDownload PDF (931K) -
Yoshifumi SAKURAI, Shunsuke SUGATANI1965 Volume 1 Issue 2 Pages 129-138
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, the rectangular hysteresis magnetic material has been adopted as the computer memory, but the principle of this device is based on the characteristics of binary counter corresponding to two saturated flux levels.
As a unique application of the memory core, the analog memory element and decimal counter have been developed by using the rectangular hysteresis magnetic material. This material has been already applied to the reliable and compact decimal counter. The authors constructed for the input decoding stage of digital computer a magnetic memory device having A-D convertible function which constantly generates pulses from zero to nine to the input analog voltage. In this device the digitalized information is alternatively memorized by two magnetic cores. S-N ratio is improved by exchanging the information between two cores and the information is stored as the decimal signal.View full abstractDownload PDF (3981K) -
Yoshihide IGARASHI, Shuichi NITTA1965 Volume 1 Issue 2 Pages 139-145
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIndustrial instrumentation signals to analog input unit of process control computer are usually low level differential d.c. voltage between the lines of the signal wire pair. For this type of signals, the common mode voltage appearing between each line of the signal wire pair and the system ground is considered a major source of input error voltage. Increasing the common mode rejection ratio (CMR) is important to improve the accuracy of analog input signals. The CMR is defined as the ability of the input system to distinguish the signal voltage from the common mode voltage. It has been extremely defficult to cope quantitatively with these problems because of the multiplicity of the common mode voltage source, problems encountered in the input scanner of a computer, necessity to take the distributed constants of signal lines in consideration and the like. Described in this paper is the derivation of equivalent circuits expressible by the lumped constants and equations of the CMR for each common mode voltage source in a typical analog input system of process control computer. By using these circuits and equations, proper handling of the common mode voltage will be realized. Difficulties in quantitative analysis of errors of analog input signals have been overcome.View full abstractDownload PDF (915K) -
Masami ITO, Hiroaki KIMATA1965 Volume 1 Issue 2 Pages 146-153
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper the authors have revealed the relations between the transient and steady-state characteristics of the zero non-regular control systems with a zero in the right-half root plane, and the pole-zero configurations of the closed-loop transfer functions in the root plane, and considered on the determination of the closed-loop transfer functions satisfying some specifications. The summarized conclusions are as follows.
1. If the location of the zero in the right-half plane is nearer to the origin than those of the poles in the left-half plane, the indicial response of the system exhibits the large undershoot and the large overshoot.
2. Because of the existence of the undershoot the minimum value of the integral of squared error (ISE) of the system is obtained for non-oscillatory one.
3. The presence of the zero located near the origin on the real axis in the left-half plane, which makes both the undershoot and the overshoot larger, renders the rise time shorter and reduces the steady-state velocity error. Thus the system designer is forced to choose the pole-zero configuration by a compromise between the steady state velocity error and the undershoot (or the overshoot to design type-I servomechanism.View full abstractDownload PDF (812K) -
Kunihiko ICHIKAWA1965 Volume 1 Issue 2 Pages 154-162
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSBy the technique of Bogolybov asymptotic method the author clarified the nonlinear gain characteristic necessary to reduce the system to hard oscillation system. When the system contains such a nonlinear gain element as reducing the system to hard oscillation system, the system may comes up to stable system, to hard oscillation system or to soft oscillation system according to the value of linear gain constant. When the gain constant is adjusted to a value which causes hard oscillation, the system in the stationary state will begin to oscillate by the reception of step input of magnitude within certain range and the existing oscillation will die out by the reception of step input of magnitude within certain another range at the proper instant. The author revealed that it is possible to cause the start or stop of oscillation not accompanied with any transient phenomena by selecting the magnitude of step input properly in each case. The electronic simulation experiments are also made.View full abstractDownload PDF (1161K) -
Yutaka SUZUKI, Tatsuo TOGE, Katsuhiko FUJII, Masataro NISHIMURA1965 Volume 1 Issue 2 Pages 163-173
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes the identification problem of a linear continuous process in the operating condition, by applying the least-square method with an aid of a digital computer.
At first, a discrete model with unknown parameters is fitted to a continuous process. The identification is performed by estimating these parameters so that the sum of square of difference between the model and process output becomes minimum. The sampling period of the input and output data is determined at an appropriate value in reference to a specified estimating function of the output. The necessary length of data depends on the noise added in the output.
Practical computing procedure and program developed are explained briefly. The results of the identification of various processes which are simulated by using an analog computer are sufficient enough. For example, when the signal to noise ratio between the input and the noise added in the output is 10, the identification is performed in the good accuracy by using a length of data equal to 20 times the settling time of the process.View full abstractDownload PDF (2673K) -
Tohru IDOGAWA1965 Volume 1 Issue 2 Pages 174-181
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method similar to the stroboscopic observation for measuring the impulse response of linear system was applied to sonic systems. The method essentially makes use of a peculiar periodic property of the autocorrelation function of a signal derived from a maximal-length binary shift register sequence which is applied to the input. A quick impulse response can thus be recorded directly on a rather slow pen writing oscillograph with the scale of time magnified by a factor of several thousands.
The value of sound velocity measured from the recorded impulse response of the sonic system, which was formed with a speaker and a microphone, agreed with that at the room temperature. The distance to a wall was also measured from the impulse response caused by the sound wave reflected at the wall surface.View full abstractDownload PDF (2458K) -
Kenji ARAKI1965 Volume 1 Issue 2 Pages 182-188
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSHigh pressure gas servomechanisms were developed for the use of space rockets and others, and some researches have been made on them in America. In Japan, however, they are scarecely investigated as yet.
With high gas pressure, as the flow velocity in some orifice and some nozzle gets to sound velocity and so as the weight rate of flow becomes saturated, the performance of gas servomechanisms comes to differ from that of low pressure.
Considerable congruitiy between theoretical nozzle-flapper static characteristics and the results of the experiments with medium pneumatic pressure was assured.
Characteristics of nozzle back pressure pn with nozzle-flapper clearance X was not changed so much even if the ratio Dn/dn (Dn: outer diameter of nozzle end surface, dn: nozzle hole diameter) changed from 1.5 to 7.
As for nozzle jet force characteristics, it was found that remarkable non-linearity occurred at some range of the ratio Dn/dn, and so it may cause unstability of pneumatic servovalve.
Considering characteristics of both X-pn and nozzle jet force, it is better to use smaller ratio of Dn/dn (for example under 2).
In case that the ratio Dn/dn is small (for example under 2), approximate nozzle jet force can be easily calculated, but difficult in case that the ratio Dn/dn is large and that there exist shock waves in the pass of air along the nozzle end surface.View full abstractDownload PDF (641K) -
Masakazu EJIRI1965 Volume 1 Issue 2 Pages 189-198
Published: 1965
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe characteristics of the torque variation in 2-phase servo-motor is analyzed using analog computer, and the causes of the vibration when the servo-motor rotor is fixed through finite stiffness are investigated. In the forceservo system particularly in the servo-manipulator, this vibration bothers the operator's sensibility in manipulation.
In consequence, it is clarified that the asymmetric circuit constants of two windings, the amplitude difference in applied voltages and the phase difference in two voltages could not be the direct causes of rotor vibration, but that, (1) higher harmonics or d.c. component in applied voltages, (2) dependency of source impedance on the feed current and (3) unbalance of rotor coils, generally cause the time variation in the stall torque of the servo-motor, and then induce the rotor vibration.View full abstractDownload PDF (4134K)
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