In order to improve the riding comfort of railway vehicles, it is effective to suppress the vibration of the vertical bending mode. Therefore, we proposed a method to suppress the vibrations by using the damping force control system of axle dampers which are installed between bogie frames and wheel sets. The semi-active control algorithm which controls axle dampers is based on skyhook control theory or LQG control theory. Numerical simulations and running tests on SANYO-SHINKANSEN were carried out, and we show that the proposed control method effectively reduces the first mode bending vibration of the carbody floor.

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This study aims at achieving simultaneous realization of ride comfort and steering stability in the controller design for semi-active suspension considering the most sensitive frequency range of human body and vehicle behavior for steering feel. In this study, the algorithm which can improve both the ride comfort and steering stability is proposed by separating the control range in terms of frequency domain. In consideration of the above concepts, we designed frequency weightings and the criterion function in frequency domain. Furthermore, we proposed the design of the integrated controller which could lose a phase difference (pitch and a roll) to improve a feeling of human steerage as well as a controller for vibration reduction in this study. And we confirmed utility of the suggestion technique through simulation.

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Optimizations of the lateral and longitudinal tire force distributions based on tire workloads are investigated. In previous studies, the authors realized minimax optimizations for several configurations of independent steering vehicles; these were realized by employing numerically robust combinations of an algebraic approach, the bisection method, and the golden section method. The purposes of this study are to investigate the applicability of optimality condition approach to minimax optimization and to consider the exploitation of complementarities between lateral forces and longitudinal forces in yaw-moment generation to further reduce the objective function. The problem for independent four-wheel steering is introduced, assuming equivalent tire workload for simplicity. A simple equality constraint is derived for the first optimality condition. On the other hand, complementarities between the lateral and longitudinal forces provide another degree of freedom. A similar formulation and optimality conditions provide stable convergence by the Newton-Raphson method.

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In lane keeping control systems, relative lateral distance and relative yaw angle between vehicle and target lane must be measured. Therefore, if the direction for center of curvature is unknown, it is difficult to measure lateral distance and yaw angle. To overcome the problem, an approximate measurement of the states is developed. In this paper, to confirm the effectiveness of the developed approximate measurement, numerical simulations are carried out in the presence of measurement noise caused by an approximation.

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This study verifies the Steer-By-Wire technology for motorcycles by computer simulation using multibody-dynainics model. The mathematical model for controller design is identified from simulation results using system identification method. The SBW controller is designed by Linear Quadratic Gaussian control theory Simulation results of the SBW control show that the actual rolling angle follows the desired rolling angle intended by the rider. The controller has some robustness in comparison with the Proportional Derivative control.

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In this paper, a new robust active suspension control scheme is developed so that ride comfort at any specified location becomes best. To achieve this end, a combined ideal vehicle is designed so that ride comfort at a specified location becomes best by using only one design parameter. To achieve the good property stated above in real vehicles, a robust tracking controller is proposed. It is shown by numerical simulations that ride comfort at a specified location can he easily improved and good robustness for front and rear suspension stiffness, damping rate and tire spring stiffness is confirmed.

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In the superconducting magnetically levitated transport (Maglev) system is a focus of interest as a future mode of ultra high speed transport. The purpose of this study is to improve ride comfort of Maglev vehicles by reducing vibrations of the vertical and pitching motions of the middle and tail cars using optimal preview control theory. In this study, secondary suspension installed actuators and applies to LQ and optimal preview control. Simulations verify that preview control enable to reduce vibration both transient and steady-state response compared with optimal control.

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Having the mission of a satellite become more complicated and multiple, especially an earth observing satellite must satisfy the two ambivalent requirements, or high agility and high accurate pointing. In order to achieve this requirement, this paper uses Variable Speed Control Moment Gyros or VSCMG as a satellite attitude control actuator and proposes a new steering law of VSCMG. VSCMG is a single gimbal control moment gyros where the wheel speed is allowed to be variable and is able to act like both CMG and RW. Proposed steering law is especially designed for a small earth observing satellite such as disaster monitoring one which is required high agility and pointing accuracy. The numerical simulations are carried out by giving a rest-to-rest maneuver and confirm the validity of this proposed method.

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This paper deals with model following control of a model helicopter with three degree-of-freedom. The online parameter estimation technique is introduced. The integral type of estimation model is proposed here since the use of the derivative type of model cannot obtain the desired estimation result. In addition, we introduce extra terms into the equations of motion that express model uncertainties and external disturbances. The experimental results show the effectiveness of the proposed method.

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This paper deals with modeling and vibration control of an isolation system which has a lightweight isolation table. If loading structures are set up on a largescale-lightweight isolation table, three-dimensional coupled vibration modes are generated between the isolation table and the loading structures. In this paper, "modeling method for elastic body with arbitrary boundary conditions by using Extended Reduced Order Physical Model" is applied to obtain a dynamical model that can describe three dimensional vibrations of elastic structure. The vibration controller for the isolation system is obtained by using this model with the LQ control theory. Moreover, simple modeling procedure of Extended Model for the isolation table is presented.

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This research aims at reducing vibrations of the conveying winch where parameter fluctuates by placing the object. The hybrid vibration isolation device which jointly uses the spring, the damper and the actuator is formed. Therefore, in this model, the control system is designed by using the robust control theory. The numerical simulations about the hybrid vibration isolation system containing the control system are performed, and the robust control effect for the vibration of the overhung rotor is examined.

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Ultrasonic dental scalar is the instrument to remove dental calculus using ultrasonic vibration of a transducer. The transducer is used in resonant condition. However, it's resonance frequency change with value of input voltage to the transducer and condition of contact with a tooth or gum, so we produced the system that traces change of resonance frequency and generates driving signal at the frequency. In addition, we proposed to diagnose dental abnormality using the system and transducer. This paper reveals its possibility.

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This paper describes the separation and transportation of works using elliptical vibration in the condition to exceed the jumping limit. In the verification experiment using electronic parts, many parts were separated by face/reverse side at high speed by giving the vertical vibration of 1.2G-1.8G. For, only face side's characteristics of transportation changed considerably when the vertical vibration exceeds 1.0G., and the difference between face and reverse side's transportation velocity is widened. To clarify this cause, we observed the behavior of electronic parts in detail. Besides, we studied the reason why characteristics of transportation changes with jumping.

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Because the magnetic force has nonlinear characteristic, nonlinear phenomena may occur in the rotating machinery supported by magnetic bearings. This study derives the fundamental nonlinear model of the magnetic bearing by transforming the magnetic flux densities of magnetic poles into the symmetric representation form. The PI control characteristics of amplifier and delay characteristic of magnetic force for the control electric current are considered in the modelling. The nonlinear vibration analysis can be performed both simply and acurately by utilizing this derived model. The influences of the dynamical parameters of both PD control and PID control are clarified, and obtained theoretical results are validated by the experiment.

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There are many harmonic components in the electromagnetic force caused by electrical motors. The harmonic components induce the structural vibration and noise. In the paper, electromagnetic vibration and noise from eccentric motor are experimentally discussed comparing with normal motor. As a result, maximum vibration is about 5 times and the noise is about 10 dB above comparing with those of normal motor.

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Vibration characteristic of a rotor supported by a PID controlled magnetic bearing is investigated. The differential equation of motion is derived with nonlinearities of the magnetic force for the gap, the current, the characteristics of a current amplifier and also the weakening of force due to surface eddy current caused rotation of the rotor. The influence of the rotational speed on the magnetic force is approximated by a fractional function and the coeffcients are determined by experimental results. By this approximation, the resonance curves for a major critical speed by the shooting method have good agreements with the experimental results.

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In steam-turbine manufactures, there are two main design groups; rotor (shaft) dynamics and blade dynamics groups who work independently. The former mainly calculate critical speed design of the shaft-bearing system. The latter design the off-resonance of blade vibrations at higher modes. However, we must consider the interaction between shaft vibration and blade vibration concerning the blade modes designated by nodal diameter k=0 and 1. This paper presents a theoretical analyses of coupled vibration between blade in-plane (nodal diameter k=1) vibration and shaft parallel motion from the viewpoints of stability and resonance. It also presents an experimental analysis using coupled resonance vibration data.

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In practical rotating machinery, the nonlinear spring characteristics appear due to various causes. As the results, the resonances occur in various roational speeds in addition to the vicinity of the major critical speed. In the passive vibration control method, it is difficult to adjust system parameters which satisfy the optimal vibration suppression condition in the whole rotational speed. In the active vibration method, using control devices are usually complicated and costly. This paper shows the method utilizing discontinuous spring characteristics, which was proposed to suppress the harmonic resonance at the major critical speed in a linear rotor system, is also effective to suppress nonlinear resoances. The vibration suppression of the harmonic resonance and the subharmonic resonance of order 1/2 are studied. However, some problems exist when ths method is applied in a nonlinear rotor system. The validity of the proposed method is also verified by experiments.

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Washing/Spin-Dryer machine is different from general machinery in the following points. It has a relative large unbalance when the clothes tend to clump in a rotating washing/spin-dryer machine. In addition, the magnitude and the direction of this unbalance also easy change because the amount of laundry varies in every operation. As the result, extremely large vibrations occur. Although various methods for vibration suppression have been used in a washing/spin-dryer machine, the effect of these method is not enough and large vibrations still appear. In this paper, we propose to use the vibration suppression method utilizing discontinuous spring characteristics together with an automatic ball balancer to suppress those vibrations. The results show that amplitude of vibration can be suppressed to a small amplitude in the vicinity of the major critical speed and a zero amplitude in the speed range higher than the major critical speed. The validity of proposed method is confirmed theoretically, numerically and experimentally.

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The repulsive-type magnetic bearing can support the rotating shaft without contact by utilizing the repulsive force between magnets. In order to suppress the vibration of the overhung rotating shaft, a vibration suppression device without contact is desired, and this repulsive-type magnetic bearing is suitable for that. This paper investigates the vibration suppression methods by controlling the axial displacement or magnetic flux density of the outer magnet of the repulsive-type magnetic bearing. Especially, the method by controlling the axial displacement of the outer magnet indicates desirable vibration suppression effects for both stationary and nonstationary vibrations at the major critical speed. Moreover, the optimization for controlling the axial displacement of the outer magnet is performed.

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Squeeze film damper has been widely used in important rotating machinery such as aero engines to attenuate vibrations and to improve the system stability. This paper proposes an expansion of application of the damper for small and medium sized rotating machinery. A new design of the damper consists of the thin ring and special patterned wire cut grooves. This damper has centering spring mechanism and damper clearance in only a damper ring. Author aims to apply this damper to the rotating machines which has a rotor system supported on oil film beatings and to verify improvement effect on vibration characteristic.

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When calculating the vibratory response of bladed turbine disks, it is assumed that all blades on a given disk are identical. This leads to the prediction that all blades experience the same amplitude. However, it has been shown experimentally that significant variations in these amplitudes occur for different blades on the same disk. These variations arise due to the effects of mistuning, which refers to small differences in blade characteristics. Although the mistuning effect on the resonant response has been studied systematically, few papers have researched the mistuning effect on the random vibration. This paper, first, presents the analysis method of the mistuning effect on the random vibration. Second, the mistuning analyses for the random vibration and the resonant vibration of the bladed turbine disk are carried out, and the both results are compared. From these results, the mistuning effect on the random vibration is clarified.

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The purpose of the study is to investigate high-speed turbomachinery system stability. Unstabilizing force due to Thomas force induced by turbine reduces a system damping at critical speed. In this paper, high-speed turbomachinery system is modeled using FEM, and natural frequency and damping ratio are calculated by a complex eigenvalue analysis, using the double QR method. In order to estimate the unstabilizing force, first torque generated by turbine blades is calculated by CFD, then cross coupling stiffness is calculated by the torque. As the calculation results, the system damping is reduced by cross coupling stiffness from complex eigenvalue analysis results.

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Subsynchronous vibration of centrifugal compressor is one of the important problems of rotating machinery. The stabilizing efforts in labyrinth seals and bearing are applied successfully; however, the destabilizing force from impeller could not be fully solved. Then, authors make a plan to solve this problem from the basic point of phenomenon. At first, the basic experimental model was developed to realize the subsynchronous vibration in laboratory. One is fiber reinforced plastics impeller which has relatively large diameter and very light weight, the other is very slender rotor which gives low natural frequency and very small damping.

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Bump foil journal bearing is an applicant for bearing which can support a small-sized rotor of high-speed rotational machinery, such as a micro gas turbine. The bearing consists of a cylindrical smooth top foil that is supported elastically by a corrugated bump foil. The top foil deforms when the assembly preload of the bump foil is applied. This study aims at predicting the maximum bearing load capacity with the effect of the preload considered and it is cleared how strongly the design variables of the bearing affect the capacity.

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A simple degree of freedom dynamic model of variable stroke swash plate mechanisms are proposed attempting to suppress noise and conserve energy of the variable displacement compressors. A dimensionless form of the proposed model enables us to characterize geometric nonlinearities of the mechanisms. Based on this dimensionless form, the authors propose an equivalent design technique by which one can convert a designed specification to another specification having different geometries but producing equivalent dynamics to the original specification.

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We proposed a method to evaluate eingenvalues of a rotor-bearing system using the modal open loop transfer function. We applied the method to a rotor supported by active magnetic bearings(AMBs). The modal damping ratio was measured by using the modal open loop transfer function of the AMB control system. In this paper, the method of deriving a modal open loop transfer function and the method of measuring modal equivalent mass are described. As a result, we concluded that the damping ratio in this method was more accurate than the damping ratio using a conventional open loop transfer function.

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This paper describes coupled vibration of oscillators mounted on a plate which hung with four strings and shows experimental results and numerical simulations. The following results were obtained. First, when natural frequency of the oscillators and the support are almost equal, the amplitude of the support is very small. It is because the driving forces of oscillators are insufficient. When the number of oscillators is two, phase difference becomes 180 degrees, and it becomes 120 degrees when the number of oscillators is three. When oscillators are four or more, phase difference is not a steady value. Second, when a support vibrates violently, oscillators synchronized and vibrate with a corresponding phase. Sufficient driving forces of oscillators are required for large vibration amplitudes of the support.

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Flow induced vibrations of tube array occur in general heat exchangers and nuclear reactors. They cause the tube failures through fretting wear or fatigue. The experiments were conducted in cylinder bundles, 15 cylinders ( 3 rows and 5 columns) and 231 cylinders (21 rows and 11 columns) at various flow velocities. The two types of cylinders were made of piano wire and plastic optical fiber (POF ). In the case of 15 piano wire cylinders, the amplitude increases as flow velocity increases and cylinders move largely in transverse direction. For 15 POF cylinders, most cylinders vibrate greatly owing to their small flexibility with frequent collisions of cylinders. In a cylinder array of 231 cylinders, spatial behaviors of cylinders exhibit a pattern like a wave-like motion as flow velocity increases.

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This paper presents experimental results on chaotic vibrations of a thin annular plate. The plate is clamped on outer edge and free on inner edge. When the plate is subjected to lateral periodic excitation, chaotic responses are observed within the large amplitude response. Predominant resonance is generated due to internal resonance. Principal component analysis is adapted to find the mode contributions to the chaos. The time responses of the plate are measured at four positions simultaneously. As a result, principal component analysis for the short time period of the chaotic response shows the existence of traveling waves in the chaotic response of the annular plate.

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Experimental and anlaytical results are presented on modal interaction in chaotic vibrations of a shallow clamped arch deformed by initial axial displacement. Chaotic responses due to internal responce and dynamic snap-through are observed in specific regions of the exciting frequency. The responses are examined by the Fourier spectra, Poincare projections and the maximum Lyapunov exponents comparing the analytical and experimental results. Contribution of each vibration mode to the chaotic vibration is then analyzed by the Karhumen-Loeve transformation. The chaotic vibration generated from internal resonance including super-harmonic resonance of second and third modes has relatively large contribution of higher vibration modes. Chaotic vibrations including dynamic snap-through generated from sub-harmonic resonance of the lowest vibration mode have relatively large contributions of asymmetric mode.

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Parametric resonance occurs in systems with nonlinear restoring force and sinusoidal excitation whose frequency is in the neighborhood of twice that of the systems. The unstable region of the parametric resonance changes according to magnitude of the quadratic nonlinear restoring force. We consider a system subjected to magnetically levitated force which is sinusoidally changed and analyze the nonlinear dynamics by using the method of multiple scales. Magnitude of the quadratic nonlinearity depends on the asymmetry in dimension of magnets and results in the change of the unstable region. Also, we experimentally confirm the theoretical result by a simple experimental apparatus.

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Introducing the mesh stiffness variation into the equation of motion of one pair of helical gear system, the effects of the mesh stiffness variation, the ratio of static torque to dynamic one, etc. on the rattle are studied by numerical analysis. As a result, the followings were made clear. (1) Because of interaction of dynamic torque and mesh stiffness variation, small resonance occurs in low frequency region. (2) The ratio of static torque to dynamic one influences the occurrence of higher harmonic resonance. (3) When the dynamic torque is larger than the static one, higher harmonic resonance with larger amplitude than that of fundamental resonance occurs in extremely low frequency. (4)The acceleration amplitude of resonance at low frequency, and that of higher harmonic resonance are large enough and comparable to the amplitude of main resonance.

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While operating contact rotating machines, a periodic polygonal deformation pattern is formed on the surface of roll and vibration problems often occur. Such phenomena are called pattern formation phenomena. In previous research, an occurrence mechanism of the phenomena was clarified as unstable vibration due to time delay characteristics. It is necessary for analysis of the actual vibration characteristics after the vibration grows to consider nonlinearities. In this report, single-DOF cylindrical grinding system with nonlinearities is treated. The periodic solutions of the system are obtained with the harmonic balance method. In addition, the polygonal number which appears is surveyed.

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The vibration suppression becomes very important for designing the helicopter to ensure the comfort and safety. In some kind of helicopters, the pendulum absorbers are adopted for the purposes to reduce the vibrations. But, the drawback is that the dimensions of the pendulum absorbers are determined by the anti-resonance concept based on the linear theory. Also, its characteristics are not analyzed completely. In a helicopter, periodic forces act on the blades due to the influences of the air thrust. These periodic forces act on the blades with the frequency which is the integer multiple of the rotational speed of the rotor. In our previous report, we proposed a 2-degree-of-freedom model of the rotor blade and the pendulum absorber. The blade is considered as a rigid body. The blade is excited by giving a sinusoidal deflection at its end. In this paper, we proposed a 3-degree-of-freedom model by adding the fuselage, and gave periodic forces on the blade. The vibration is analyzed considering nonlinear characteristics. We show that the vibration is well-suppressed by the pendulum absorbers.

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In order to reduce the vibration of helicopters, the pendulum absorbers are often adopted. But, most of the papers analyzed its characteristics based on the linear theory and explained focusing on the anti-resonance point. Since the pendulum may vibrate with large amplitude, it is expected that the nonlinearity have essential influence on its vibration characteristics. Therefore, we investigated the vibration suppression of the pendulum absorber considering its nonlinearity. In our first report, we proposed a 2-degree-of-freedom (2DOF) model composed of a rigid rotor blade and the pendulum absorber. The blade is excited by giving a sinusoidal deflection at its end. In the second report, we proposed a 3DOF by adding the fuselage. In both of these papers, the blade is considered rigid. The blade is excited by a sinusoidal distributed force. In this paper, a 3DOF model which is composed of a mass corresponding to a rotor mount on the fuselage, a flexible blade, and a pendulum. A periodic distributed force is given on the blade. We show that the vibration is well-suppressed by the pendulum absorbers.

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The characteristics of three nonlinear dynamic absorbers attached to structures under horizontal-harmonic excitation are investigated. The frequency response curves are theoretically determined using van del Pol's method. It is clarified from the theoretical analysis that a part of response curves, which are stable in a system with one nonlinear dynamic absorber, change to be unstable and that five branches for steady state solutions may appear. The absorbers vibrate in different amplitude and the system may encounter saddle-node bifurcations and Hopf bifurcations depending on the values of the system parameters. The excitation frequency range and the values of the system parameters for amplitude modulated motion appearing after Hopf bifurcations can be determined by bifurcation sets.

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It is known that the development of peripheral neuropathies and peripheral circulatory disturbances in the hand-arm vibration syndrome is caused by operating hand-held vibrating machines for a prolonged period. The purpose of this research is to newly develop a vibrating machine utilizing self-synchronized phenomena in order to reduce the hand-transmitted vibration. In this paper, two types of coupled oscillators for a rammer which is a kind of vibrating machine are suggested. The self-synchronized solutions and its stability are analyzed by applying the shooting method. From the analytical results, the mechanism which can generate the optimum self-synchronized solution for realizing utilization of vibration and vibration control at once is examined.

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This paper investigates the modelling of one-degree-of-freedom magnetically levitated system considering both the PI control characteristics of power amplifier and delay characteristic of magnetic flux density in the electromagnet is performed. Especially, the directional characteristic of the general power amplifier is considered in the modelling. Then, the nonlinear resonance phenomena and bifurcation phenomena in this model are studied. The numerical simulation and the theoretical results show good agreement. Theoretical results clarify the influences of dynamical parameters of the magnetically levitated system on the nonlinear vibration phenomena in detail. Furthermore, the performed experiment validates the obtained theoretical results.

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The purpose of this work is to identify the characteristics of a nonlinear vibration system subjected to a random input. In a general, a statistical technique of a higher order spectra(HOS) could be used for non-gaussian data analysis. Here, exiperimental model (Magnetic model) analysis was executed for an asymmetrical nonlinear vibration system,and showed nonlinear mappinng.

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The governing equations of motion of a nonlinear continuous system are described by a set of nonlinear partial differential equations and boundary conditions. Determining both of them simultaneously is a quite difficult task. Thus, one has to discretize the governing equations of motion, and reduce the order of the equations as much as possible. In analysis of nonlinear vibratory systems, it is known that one can reduce the order of the system by using the nonlinear normal modes while preserving the effect of the nonlinearity accurately. In identification it is expected that an accurate mathematical model with minimum degree of freedom can be determined if one can express the response as nonlinear functions of the coordinates for identification. Based on this idea, in a previous report the authors proposed an identification technique which uses nonlinear principal component analysis by a neural network. In this report, procedure to apply the identified result to structural modification is presented. It is shown via numerical example that when the structural modification is not so large, response prediction of the modified system with enough accuracy is possible.

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A rational reduction method using modal analysis is developed in order to analyze accurately a large-scale nonlinear system. Nodes without nonlinear excitation are transformed into the modal coordinates, and the modes with significant effect on computation accuracy of the vibration analysis are extracted. On the other hands, the remaining modes with small effect are appropriately approximated and are eliminated. The very accurate low-dimensional model is constructed by these procedures. The effectiveness of this method is verified from the computational results.

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Today, we need more lightweight and more high stiffness panels, because of environment concern. Especially this demand is strong for automobile vehicles. Here we examine the application possibility to the door structure for the side collision of vehicles etc., paying attention to the Truss Core Panel, invented by Nojima based on "filling theory". Then, we evaluate its bending characteristic through the dynamic non-linear FEM simulation. And we select design variables of Truss Core Panel to examine the sufficiency of its bending characteristic. In this research, three conclusions are obtained as follows; 1) The evaluation value becomes high by making the "flat rate gamma" small 2) The evaluation value also becomes high as "triangular pyramid cutting" length becomes large. 3) If panel board thickness becomes 60% or less, the evaluation value greatly down. Thus, it is important to calculate the optimal value considering both of "formulability and bending characteristic" for its utilization .

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We have already tried to reduce booming noise, which is one of the interior noise of a vehicle cabin, by using Helmholtz resonator whose throat is Origami structure to vary its length. From FEM analysis quite amount of noise level reduction was obtained. In this study several resonators are attached to appropriate positions of a cabin and large amount of noise reduction is obtained. Moreover, we investigate whether the booming noise would really reduced by an experiment. The simplified cabin model is manufactured and the resonator model whose throat is Origami structure is attached to the cabin model. Small amount of noise reduction is obtained but since Origami structure is not rigid the change of eigenfrequency of the resonator cannot be obtained by varying the length of the throat. From this result it is concluded that the throat of the resonator should be manufactured like a telescope.

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In this paper, a new type drive system of the MEMS (micro electro mechanical systems) resonant-type optical scanner is proposed and researched feasibility of a practical use. In this drive system, scanner mirror is supported with two pairs of bars which are stepped in a opposite direction each other. When the harmonic axial force is applied to the ends of the supporting bars, torsional vibration of the mirror is excited due to the deflection of the bars. The effects of the bar dimensions on resonance frequency, amplitude of rotation angle and maximum value of the first principal stress are investigated by comparing simple theoretical results with FEM-based simulation.

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This paper proposes a system to transmit energy to a micro-vehicle using high-power laser, and to drive it. The system consists of two different systems, one is noncontact laser energy transmission system using high-power diode laser and photoelectric conversion element, and another is laser tracking system that constantly irradiates laser. Solar cell is used as the photoelectric conversion element. Each system requires an own laser and each laser requires its own specifications. The optical composition to integrate two systems without interference is proposed. The fundamental system is developed and its performance is confirmed throughout the experiment.

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By processing triangle or square pyramid shaped indents on a flat sheet following regular plane tiling patterns, panels with periodical indents are manufactured. By setting a panel piece (as top panel) on reversed one (as bottom one), and gluing them at the apexes of pyramids to nodal points of the tiling patterns of bottom panel, highly rigid core panels are newly developed. By analyzing mechanical property of these core panels with experiments and numerical simulations, it is clarified that surface patterns affect panel rigidity, and they are able to compete with honeycomb at the point of specific rigidity

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Although it is not impossible to manufacture 3 dimensional structures by an Origami technique using conventional flat sheet, from the engineering standpoint, the range of producible models become confined for the complexities of the manufacture procedure. Therefore we try to use geometrically prescribed uneven sheet with periodical indents instead of a flat sheet to achieve an easy processing of 3D structures. By using such sheets, several geometrically simple structures such as rigid mast and plates were manufactured.

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By allowing elastic deformation in truss members, it is investigated whether or not shape-changable/variable geometry truss structure can be designed based on the origami models of foldable cylindrical and conical shells. Stability (or instability) and statically determinate(or indeterminate) conditions in truss structures, whose nodes consists of 6 members are examined under conditions with both rigid members and elastic members. It is exemplified that foldable/deployable truss structures can be designed when members are elastic.

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Recently, the senior citizen's independence is requested in aging society. We are researching the Walk-Supporting Devise from which the senior citizen can stroll in the town. There is a place over which it doesn't pass easily in the town for the walker such as dirt roads. We overcome the problem by making the steer limitation device that uses the cam and are aiming at the completion of the Walking-Support-Device for the monitor. It has been understood that the steer limitation device that uses the cam as a result of the experiment is effective though stabilizes straight advancement

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