All issues
Volume 2 (1966)
- Issue 4 Pages 237-
- Issue 3 Pages 165-
- Issue 2 Pages 75-
- Issue 1 Pages 1-
Volume 2, Issue 1
Displaying 1-9 of 9 articles from this issue
- |<
- <
- 1
- >
- >|
-
Suguru ARIMOTO1966 Volume 2 Issue 1 Pages 1-7
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper discusses a linear feedback control system subjected to gaussian white noise. and gives an optimal linear feedback control law which minimizes the integrated-mean-square error criterion. The method used in this paper is based upon the analysis of Ricatti-type matrix equations derived from the optimal regulator problem. The duality relating covariance matrix equation and mean-square deviation equation plays a central role in the evaluation of the rms error.
The main result is that the optimal linear feedback control law minimizing the rms criterion is equivalent to the feedback law of the optimal regulator.View full abstractDownload PDF (736K) -
Rinzo EBUKURO1966 Volume 2 Issue 1 Pages 8-14
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSEasier setting, easier modification and easier confirmation of the settings are the principal features of the plug board input system. However the ordinary plugboard system has certain inconveniences such as the limitation of the number of settings, the wider surface area of the board and some difficulties of preservation of settings. So, ordinary control systems with plug board input method have a restricted application. NEDAC-313A N/C positioner overcomes these difficulties by the principle of repeated sequence control. It is very obvious that we have more number of actual processes than the number setting processes by adding the sequence repeater to the ordinary controller. The positioner has only 40 setting processes but it gained 391 actual processes, or more, by repeated sequence control.
Furthermore, we make one process correspond to one working or one hole. In other words the working includes different operations such as drilling, drilling only or accurate table positioning and drilling, with spindle indexing or not, tapping, table movement only etc, but our controller makes each working act as one process. We have several improvements on the controller with plug board input system such as:
(1) It reduces the setting work and setting time.
(2) It allows the flexibility of the actual settings on the plug board.
(3) It reduces the setting surface area. So the small size mask enables preservation of the program for plug board.
(4) We can check the machine operation easily.
The controller described in this paper controls BURGMASTER-CHUKYO 1-DHP turret drilling tapping and reaming machine, and it supplies efficient cuttings.View full abstractDownload PDF (2194K) -
Masakazu EJIRI1966 Volume 2 Issue 1 Pages 15-21
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSStability problems of 2nd order time-varying damping system, which has the characteristic eguation of the form
d2θ/dz2+(k1+k2sinz)dθ/dz+pθ=0,
are investigated using Hill's method.
At first, it is shown that Hill's method is applicable without any modification to the extended Hill's eguation having not only cosine terms but also sine terms. Further, the means to find the stable and unstable regions in parameter space of k1, k2 and p, using digital computer, are shown.
As the results of this analysis, it is clarified that the time-averaged damping coefficient k1 and stiffness p must not be negative for necessary condition of stability, and that, even if k1 is positive, the system can be unstable in the vicinity of p=0.25 by the effect of time-varying damping coefficient k2 when approximately |k2|>2k1.View full abstractDownload PDF (815K) -
Kamekichi SHIBA, Mitsuharu SATO1966 Volume 2 Issue 1 Pages 22-26
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis report is concerned with a new method of grain size analysis by sedimentation. The new method is also based on the assumption that all particles in a liquid descend with constant velocities dependent on their sizes. But the incorrect assumption, that the specific gravity at a level of a muddy liquid is measured by a hydrometer, is not introduced in the new method.
An equation is deduced which gives the integrated percentage as a function of the apparent increase of mass and its time derivative of a circular cylinder, partially immersed in the muddy liquid.
It is proved theoretically that the same equation is applicable for a totally immersed cylinder, under the condition that all particles initially exist in the part of the liquid over the cylinder remain permanently in that part.View full abstractDownload PDF (658K) -
Kamekichi SHIBA, Kiyoshi OISHI, Koichiro DOI1966 Volume 2 Issue 1 Pages 27-30
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA kind of flowmeters of reaction type is reported. The flowmeter is composed of a movable cup-shaped backet connected by some springs to a fixed flow-out pipe and coaxial inner flow-in pipe. And all of them are placed in a closed chamber. The displacement of the backet is measured by a differential transformer.
Incompressible perfect liquid flows in the flowmeter steadily, and the flow direction is reversed by the backet and so the momentum of the liquid increases by the action of the backet.
The reaction is proportional to the displacement of the backet and so the flowrate is proportional to the square root of the displacement.
The results of our experiments confirm fairly well this theoretical consideration.View full abstractDownload PDF (399K) -
Katsumi TAKAMI, Eisuke NIIYAMA, Toshiaki TANAKA, Takeomi OKUMOTO, Ryut ...1966 Volume 2 Issue 1 Pages 31-42
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTemperature of bottom working roll of the first stand of hot strip finishing mill during rolling was measured by means of both thermocouples imbedded in the roll and hardness testing of quenched steel pieces plugged in roll surface. Instantaneous temperature change was detected by the former and lead to recorder through slip rings. The maximum temperature rise extremely close to surface was estimated by the latter.
Three zones differing in their temperature rise characteristics were found in the roll body. In zone I, 0 to 5mm from surface, temperature rise was instantaneous with steep gradient. It was sensitive to rolling variables for each strip. In zone II, 5 to 30mm, temperature rise was medium and moderately sensitive to both rolling variables and rolling number. In zone III, 30mm to center, temperature rose gradually with rolling number and reached a constant after 15 or more rollings.
Dependence of temperature rise on rolling variables was examined. Amount of cooling water was found most critical in determining the temperature and the reduction rate was the second, while interval of rolling was even less critical.
A rather abrupt rise of temperature was observed when reduction rate exceeded a certain value. This nonlinear characteristics were correlated with the increase in the heat of friction between roll and strip.View full abstractDownload PDF (2025K) -
Takayoshi TOTANI1966 Volume 2 Issue 1 Pages 43-52
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a method for self-adjusting the parameters of a control system using a sinusoidal test signal. In this method, the frequency of the test signal is automatically adjusted to have 180° phase lag in the control loop, and the proportional sensitivity of the controller is adjusted to keep the gain of the test signal constant at this frequency. The integral and derivative time of the controller are also adjusted to have a fixed relation to this frequency.
This system has two self-adjusting loops, each for adjusting frequency of the test signal and for adjusting proportional sensitivity of the controller. The dynamic behaviors of these loops are equivalent to that of the first order lag system, and the increase in the speed of response of the loop is obtained by increasing the amplitude of the test signal.
The dynamic error in the parameter adjustment in this system depends on the spectral density of the process noise at the frequency of the test signal. For detecting the signal component in the control system output which contains the signal and noise, a simple demodulation technique which cross-correlate the sign of this output with a known sinusoidal signal, is proposed in this paper. It is shown that by the introduction of this technique, the dynamic characteristics of the self-adjusting loops are improved.
Experimental results of this method applied to a flow control system are also shown.View full abstractDownload PDF (1317K) -
Masakazu EJIRI1966 Volume 2 Issue 1 Pages 53-62
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt has been shown in previous papers that the torque-speed curves of the two phase servomotor are widely varying with time at non-zero speed even in steady state, with a frequency of twice line frequency. So, the inclination of the curves can be positive at some periodic time intervals, even for a stable servomotor whose time-averaged inclination is negative.
Then, the system in which the rotor is fixed through some finite stiffness can be approximated to “2nd order time-varying damping system”. From the analysis on stability of the system, it is clarified that the parametric resonance with line frequency occurs even in the case of sinusoidal excitation for stable servomotor, when system frequency is in the vicinity of the line frequency.
Therefore, in force servomechanisms, the system frequency must be chosen higher than twice line frequency in order to prevent the parametric resonance.View full abstractDownload PDF (1781K) -
Yoshikazu SAWARAGI, Yoo YONEZAWA, Megumi MIYAKE1966 Volume 2 Issue 1 Pages 63-74
Published: March 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe use of pneumatic transmission lines in automatic control and instrumentation reqires accurate knowledge of their dynamic response. Many researchers have dealt theoretically and experimentally with the frequency, step and/or impulse responses of fluid lines. The basic differential equations expressing the dynamics of the fluid lines are continuity, equation of motion, energy equation and equation of state for gas or liquid. These equation are very complex, so many researchers have made some assumptions and solved these equations by use of the methods corresponding their own objects.
In this paper, these assumptions, procedures for solutions and solutions are compared with each other. The approximately basic equations are classified into two large groups. The first group consists of the Navier-Stokes equation and the linearized equation of energy equation with respect to fluid velocity, and the solutions derived from these equations express the radial distributions of temperature and fluid velocity as well as the axial deviation of pressure and velocity. But the physical considerations with regard to dynamic response are very difficult, because the solutions consists of Bessel functions. The equations of second group are the linearized ones of Euler's equation of motion and continuity. By this solution it is found that the behaviour of pneumatic transmission lines is comparable to an electric cable involving distributed constants, thouth only the axial deviations of pressure and fluid velocity are specified by the solution.
The dynamics yet to study on the pneumatic transmission lines are as follows:
(1) the effects of end-point's impeadances of transmission lines
(2) theoretical examinations of resonance phenomena in pressure attenuation curve
(3) the change of various factors by large disturbanceView full abstractDownload PDF (1642K)
- |<
- <
- 1
- >
- >|