JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
Print ISSN : 0914-8825
Volume 34 , Issue 3
Showing 1-19 articles out of 19 articles from the selected issue
  • Seiichi USUI, Kazuo TANI, Nobumasa SHIRAI, Eiichi HORIUCHI
    1991 Volume 34 Issue 3 Pages 321-326
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    This paper describes a mathematical model of an uneven road surface where the statistical characteristics of the roughness are isotropic. A spectral density matrix is obtained in consideration of a correlation of the roughness between the right and the left tracks. By the spectral factorization of the rational spectral density matrix, which results from the approximation of the cross-spectral density function, the transfer function matrix is formulated, and the minimal realization of the shaping filter is obtained analytically. The results of the numerical simulation using the shaping filter are in good agreement with the analytical ones.
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  • Ichiro MORIWAKI, Takashi OKAMOTO, Aizoh KUBO
    1991 Volume 34 Issue 3 Pages 327-332
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    In the present paper, we discuss the possibility of roll-finishing of a quenched gear. For this purpose, we carry out experiments on the roll-finishing of work-gears which have a tooth flank hardness of HRc=40 or 55. As a result, it is found that work-gears of HRc=40 can be roll-finished without any particular techniques. For work-gears of HRc=55, we can also obtain a fairly good tooth form after roll-finishing if an undercut is provided for the work-gear and a crowned die-wheel is used with a slow work-feed in its axial direction. Furthermore, we compare the tooth form of the die-wheel after the roll-finishing with that before roll-finishing to reveal that there are no negative effects on the tool life of the die-wheel, although it may be shorter than that in the roll-finishing of unquenched gears.
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  • Hiroshi YABE, Hideyoshi ISHIDA
    1991 Volume 34 Issue 3 Pages 333-338
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    To establish a fundamental concept for the precision design of a gas bearing, the static and dynamic run-out characteristics of a rotor supported by an externally pressurized gas-lubricated thrust-collar bearing are investigated in this paper. The concept is based on the theoretical results developed in the previous papers on load capacity fluctuation, which is caused by machining errors such as the out-of-perpendicularity of the rotor-end surface and the size deviation of supply holes of the bearing, as well as on the fundamental bearing characteristics such as stiffness and damping coefticient. The "averaging effect" for the rotor run-out characteristics is evaluated quantitatively. The experimental results for the amplitude of the rotor vibration coincide well with the theoretical results, which may confirm the validity of the theoretical model used in this study.
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  • Katsuhisa FUJITA, Tomohiro ITO, Hiroshi WADA
    1991 Volume 34 Issue 3 Pages 339-344
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    The fundamental characteristics of plastic dynamic buckling of a thin cylindrical shell due to seismic excitation, where bending load was predominant, were clarified experimentally. The relationship between seismic response displacement, acceleration, strain of cylindrical shell model and input acceleration was investigated. The dynamic buckling load was compared with that for static buckling, and the differences between them, as well as the threshold for postbuckling, were discussed.
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  • Masumi KATAOKA, Shinichi OHNO, Takanao SUGIMOTO
    1991 Volume 34 Issue 3 Pages 345-354
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    The engine-clutch-gearbox train of an automobile is modeled by a forced torsional vibration system including two nonlinear terms, namely a clearance and a two-step-hardening spring. Analytical solutions of the equations of motion of the system are obtained in recurrent form. Based on the solutions, the effect of the torsional stiffness of the clutch disk on the idle rattle of the gearbox is investigated. The results are as follows : (1) The sum of torque impulses per cycle of the forced motion increases with the increase in the ratio of the second-step stiffness to the first-step stiffness. Therefore, there is an upper limit to the second-step stiffness for the purpose of the prevention of idle rattle. (2) Both the sum of torque impulses and the number of collisions decrease with the increase in the range of torsional displacement covered by the first-step stiffness.
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  • Hideyuki AZEGAMI, Tadashi OGIHARA, Akiyasu TAKAMI
    1991 Volume 34 Issue 3 Pages 355-361
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    The growth-strain method, developed using the finite-element calculation of the deforming of shapes produced by swelling and contracting of itself, was previously proposed as a shape optimization method. The present report describes an application of the growth-strain method to the problems of steady-state vibration. In particular, free vibration with a normal mode and vibrational response to a harmonic excitation are considered. A difference of the implementation of the method for these vibration problems from that for static problems lies in analyzing the stress distribution at the deformation in the normal mode or in the amplitude of the vibrational response. Numerical examinations are carried out on simple beam structures. In these examinations, the growth-strain method shows a feasibility even in the optimization of structures under dynamic circumstances.
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  • Yehia A. KHULIEF
    1991 Volume 34 Issue 3 Pages 362-369
    Published: September 15, 1991
    Released: February 18, 2008
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    A method for deriving the constrained form of Lagrangian equations of motion for an interconnected system of rigid bodies using bond graphs is presented. Intrinsically, this approach allows the formulation of the final form of equations for holonomic systems without recourse to the Lagrangian function. Consequently, the burdens of deriving the expressions for kinetic and potential energies, and performing the necessary differentiations have been eliminated. This method calls only for constructing the Jacobian matrix of constraints, and then employing a bond graph that accounts for the generalized constraint reaction forces.
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  • Ming-Chang SHIH, Yih-Ran SHEU
    1991 Volume 34 Issue 3 Pages 370-376
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    This paper is concerned with the practical application of model reference adaptive control (MRAC) on the position control of a hydraulic cylinder. In this study, the modified hyperstable-MRAC method is employed to adapt the loading effect. The reference model is based on the reduced-order model of the plant, which is derived by using the Routh stability criterion and the Pade approximation technique. A 16-bit microcomputer is used to design an adaptive controller. The experimental results are also compared with those obtained by using the classical control theory.
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  • Jong-Hwei WEI, Ming-Chang SHIH, Cheng-Ping CHIU
    1991 Volume 34 Issue 3 Pages 377-381
    Published: September 15, 1991
    Released: February 18, 2008
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    A model-following control (MFC) using proportional-integral-derivative (PID) compensator for a nonlinear plant is described. The reference model in this paper is chosen as a PID control system. This provided a very useful guide for selecting a reference model. In this article, a modified MFC system is developed via the hyperstability theory. A new control algorithm is proposed whereby the supplementary loop generates a correction signal and is superposed on the conventional PID control signal to ensure the performances of the MFC. When the supplementary loop signal is null, the MFC system is the conventional PID control system
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  • Hiroaki FUNABASHI, Mikio HORIE, Tetsuya KUBOTA, Yukio TAKEDA
    1991 Volume 34 Issue 3 Pages 382-387
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    In the present paper, kinematic structures of spatial 6-degree-of-freedom (dof) parallel manipulators are obtained by a number synthesis of multiloop linkages which consist of pairs with 1, 2 and/or 3 dof and have no moving closed loops. Concerning simple and practical manipulators among the obtained ones, that is, concerning the parallel manipulator consisting of six arms, each of which has three revolute pairs and a spheric pair, analytical equations for inverse and direct kinematics are derived and singular positions where the configurations of the manipulator cannot be defined are discussed. Moreover, taking account of allowable pressure angles and maximum swing angles of spheric pairs, the relation between the working space and parameters of the manipulator is investigated, revealing that the manipulator can operate with larger vertical motions than the Stewart Platform.
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  • Jun WU, Kenichi YOSHIMOTO
    1991 Volume 34 Issue 3 Pages 388-395
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    This paper presents a method based on time optimal control for speeding up the motion of a flexible robot arm and minimizing the residual vibration at the end of the motion. A group of equations which makes the solving of switch times of control input much easier is derived using modal analysis. In order to improve the robustness of time optimal control against parameter variations, a learning control scheme which uses state feedback to eliminate the difference between the actual system and the estimated model is added to the open-loop control, and the gains of state feedback are determined through the learning process. The convergence of this learning control is investigated in simulation, and its effectiveness is confirmed by experiment with a flexible robot arm of one joint and one elastic link.
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  • Tetsuji HIROTSU, Katsuyuki TERADA, Motomi HIRAISHI, Shigetomo YUI
    1991 Volume 34 Issue 3 Pages 396-403
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    Rail vehicles must have both good curving performance and stability at high speeds. Such vehicles have a compound circular wheel profile, soft suspension of the wheelset and yaw dampers. A detailed dynamic model (31 DOF) for these vehicles was formulated, and general equations of motion were derived considering various non-linearities such as the wheel profile, clearances in the wheelset suspension and creep forces between the wheel and rail. Digital simulations for a representative example were made. It was shown that the yaw dampers had a large effect on improving stability, especially in suppressing divergent hunting at higher vehicle speeds. Then, eigenvalue analyses for the linearized model were made and the cause of the above-mentioned effect of the yaw dampers was clarified. The influence of some other factors such as clearances in the wheelset suspension and supporting stiffnesses of the yaw dampers and lateral dampers was also considered.
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  • Satoru FUKATA, Yoshinori KOUYA, Takashi SHIMOMACHI, Yutaka MIZUMACHI, ...
    1991 Volume 34 Issue 3 Pages 404-410
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    A linear model considering the effect of eddy currents is shown to be useful for the analysis of the dynamics of active magnetic thrust bearings in which electromagnet cores are composed of solid steel. The dynamics of the magnetic control force are modeled by the first-order time-lag system with unknown parameters : gain and time constant. The parameters are estimated from experimental results that indicate the static relation between the coil current and the magnetic control force, and the frequency response of magnetic flux for an input signal to a power amplifier. The effect of eddy currents on the dynamics is confirmed by the frequency characteristlcs of magnetic flux for the coil current. Model simulations with estimated parameters are compared with experimental results, and good agreement is obtained in frequency response in a linear range and in impulse responses with rotor displacements smaller than half the air gap.
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  • Nobuyoshi KAWABATA, Isao ASHINO, Masami SEKIZAWA, Sizuka YAMAZAKI
    1991 Volume 34 Issue 3 Pages 411-418
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    A new type of grooved bearing whose axial load-carrying capacity is improved is proposed in this paper. The present type of bearing is composed of herringbone journal bearings, a spiral grooved thrust bearing and a path hole which connects the middle of each bearing. A lubricating gas flows through a path hole by the pumping effect of herringbone grooves. A generalized method of numerical calculation using the narrow groove theory is introduced in this paper for the analysis of the present type of grooved bearings. As a result of the numerical calculation, axial floating characteristics of the present types of grooved bearings are shown to be superior to those of conventional bearings.
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  • Akira YOSHIDA, Yuji OHUE, Mitsunori SAITOH, Isamu KARASUNO
    1991 Volume 34 Issue 3 Pages 419-426
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    In order to obtain fundamental data about tooth-surface durability and the tooth-surface failure mode of induction-hardened sintered powder metal gears, rollers made of two kinds of powders with diameters of 30 and 60 mm were fatigue-tested with pairs of same-diameters rollers under a sliding-rolling contact condition. The surface failure mode in this experiment was spalling due to subsurface cracking. The depth of the spalling crack agreed with the depth of the maximum amplitude of the ratio of orthogonal shear stress to Vickers hardness. The surface durabilities of the rollers increased as the relative radius of curvature decreased, and they were hardly influenced by the powder type and the sign of specific sliding.
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  • Takaaki KATOH, Eizo URATA, Minoru NAKANISHI, Kazuo YAMAZAKI
    1991 Volume 34 Issue 3 Pages 427-432
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    Seamless pipes have some terminal end bends which must be eliminated before shipment. This paper describes a real-time control system for a press straightening process. The straightening process must account for elastic springback, which is a strong function of the material properties of the pipe. On-line measurements of reactive forces and deflection of the pipe during the early part of the bending process are performed to form an elastic-plastic model in a microcomputer. The final correct die position to yield the desired unloaded shape is predicted using the elastic-plastic model. Through a series of experiments on different materials and different sizes and shapes, the resulting straightness of the pipes was within 0.18 mm, which is sufficiently smaller than product allowance.
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  • Teruoki FUJINO
    1991 Volume 34 Issue 3 Pages 433-437
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    Since present numerical control machines (hereinafter referred to as "NC" machines) invariably use proportional control, there is a large time lag intrinsic to this control. Consequently, in the state of simultaneous plural-axes control, a locus error proportional to the movement speed inevitably results. Since this servo lag error is dependent on the proportional gain and acceleration/deceleration time constants after interpolation, this system parameter adjusts for each machine in advance and interpolates the NC data that are input while always performing optimum "inverse transfer function compensation" (gain compensation and phase compensation) on the said NC data. This has completely eliminated the first-order lag error which had resulted from the high-speed process. For example, when this system is combined with the machining center HA-5VA, it can move on a steep curve up to R5 mm with the tool center locus at a tangent speed of 6 m/min without any servo lag error. In addition, as a result of incorporating the above compensatory method, this system identifies the acceleration/deceleration of the response output with high precision. This allows the system to perform automatic acceleration/deceleration without any redundancy, using 1OO% of the servo actuater's power.
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  • Mitsuru NAKAMURA, Hiroaki HATA, Yozo NAKAMURA, Tsunehiro ENDO, Kenichi ...
    1991 Volume 34 Issue 3 Pages 438-447
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    In the previous paper, the authors proposed torque control systems that may be effective to reduce vibration of a rolling piston-type compressor for a room air conditioner. This paper deals mainly with the experimental results of the torque control systems. Two types of control models, a "rotational speed control model" and a "rotational acceleration control model" were used, and the stability and the transient response were discussed in comparison with the simulation. It was shown that the experimental results generally agreed well with the simulaion predictions, although the degree of actual Control effects was a slightly inferior because of detection errors and response lags in the actual control system. By comparing both control systems wlth each other, it was proven that the rotational acceleration control system is superior and can reduce the compressor chamber vibration in a stabler and faster response.
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  • Kenjiro UEGAMI, Kentaro TAMAMURA
    1991 Volume 34 Issue 3 Pages 448-452
    Published: September 15, 1991
    Released: February 18, 2008
    JOURNALS FREE ACCESS
    The applications of a new cut off tool equipped with a grooved rake face are discussed in relation to the cutting performance compared with that of the conventional (flat-rake-face) cut off tool. The experimental results indicate the followings :1) cutting surface roughness and chip disposal are improved and cutting forces are decreased ;2) cutting forces and their fluctuations are markedly decreased as the oxygen jet is supplied to the tool edge at the range of cutting speed in which the built-up edges grow ;3) the ceramic cut off tool is capable of grooving steel work since the cut off tool has a grooved rake face and the oxygen jet is supplied to the tool edge.
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