In the present study, damping of an intrinsic vibration in human limb called physiological tremor is investigated. In most of humans the tremor is observed even at physically well condition that is derived from excessive stress or chills, therefore, it may cause anyone bad effect on precise operation such as welding and surgery. In this study experiments are performed, where the subjects are imposed a transcription task while the dynamic absorber attached to their wrist attenuates the tremor in their hands. Good results are obtained where the tremor is reduced to approximately tenth compared with the case without damper.

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In this paper, we propose the novel human interface applied to machine operation by using bite force. The bite force is measured by the strain gauge from the motion of muscle called Temporalis Muscle adjacent to temple. The measured value is divided into "large" and "small" as direction of strength and is divided into "right" and "left" as direction of right and left. Totally, the value is classified into the four kinds. We examined that bite force could be classified appropriately into the four kinds by operator's intention. As the result, 89% of trial was appropriately classified.

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Many types of machinery used in power plants are fixed by anchor bolts. When these machines experience big earthquakes, the bolt joints deform in the plastic region, loosening them, resulting in a non-linear behavior. We studied the modeling method to analyze the seismic response of machines in considering anchor bolt yield. We performed a tensile test and an elemental test to determine the load-deflection properties and the failure point for the bolt joints. We then applied the obtained properties to an analytical model, and analyzed the seismic response of machines fixed by anchor bolts. We report elemental-test and study results obtained by evaluating the seismic response of machines fixed by anchor bolts to improve yielde.

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Recently, it has been reported that the rupture of the piping in an earthquake is produced not by momentary large load but by the cumulative fatigue damage. Then it is expected that the rupture of the equipment and the piping that have high natural frequency is also caused cumulative fatigue damage. Therefore it is very important to grasp this effect accurately. In this study, the vibration characteristics at high frequency band are investigated by applying numerical analysis and fundamental experiments. Especially energy balance is applied for evaluation of vibration characteristics.

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This paper deals with nonlinear vibration of a continuum system with gaps under stationary random waves considered collision phenomena. In order to investigate this nonlinear vibration characteristic, experiments are carried out with an experimental apparatus consisting of a nonlinear vibration system. An analytical model of the cubic equation is proposed based on the restoring force characteristics in the experiments. For stationary random input waves, the probability density function of the response displacement and the response velocity are governed by the Fokker-Planck Equation. The analytical model of the nonlinear spring is applied to this equation, and the probability density function of the response displacement and the response velocity is calculated. Moreover, the probability density of the restoring force characteristics is evaluated.

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This study treats the dynamic stability of mechanical systems subjected to multi-directional excitations, such as dynamic buckling behavior, etc . A steel cylindrical pier is treated and modeled analytically as a thin cylindrical structure with an attached mass on its tip. The analysis is carried out by numerical simulations, where the horizontal and the vertical seismic loads are applied simultaneously. The effects of the horizontal and vertical input frequencies on the dynamic stability are studied. It is known that the seismic responses of the thin cylindrical shell structure tend to increase due to the coupling effects between the horizontal and vertical excitations, and that flattening phenomena make the cylindrical shell structures more unstable.

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In this paper, we focus on the singularity, which appears in the acceleration response when the restoring force of structure enters into an elastic region from a plastic region. And we confirm experimentally that we can estimate the number of entering to the plastic region using the wavelet transform. The experiment is carried out using the 5th-story structural model installed by lead rubber bearing (LRB) with hysteretic characteristics of restoring force. The experiment results that wavelet transform make it possible to estimate the number of entering to the plastic region, when a non-stationary wave is inputted into a structure.

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This paper proposes two design methods of a passive dynamic absorber with robust performance. In this study, the dynamic absorber is designed from the view of feedback control. In case of first method, the controller, i.e. design parameters of the dynamic absorber, is designed by fj, synthesis method. In case of second method, we consider that a extended generalized plant is constructed by two main systems which have maximum and minimum natural frequencies in the given variable domain, and the maximum value of frequency response of the extended plant is reduced by one controller. Finally, numerical simulations show the advantages of the proposed design methods.

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The purpose of this paper is to propose a new technique in order to approximately estimate the stochastic response of nonlinear hysteretic structure with active control by sliding mode control (SMC) theory subjected to Gaussian white noise as earthquake. One-degree-of-freedom hysteretic system is adopted as an analytical model, also active mass damper (AMD) is considered as vibration control method. Concerning the statistical values of structural response obtained by the proposed technique, the Monte Carlo simulation is also performed. Comparison of both results shows good agreement and indicates that the proposed analytical method is valid.

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This paper deals with the seismic response simulation model, which is coupled with the physical spring mass subsystem and the modal spring mass subsystem. The effect of participation factor is introduced in mass matrix and the unilateral contact model for slip and stick sue to the friction force is introduced in the equation of motion. The slip response with shaking table excitation test verified the simulation model presented here. Parametric studies for four kind of actual size tank are conducted to examine the effect of participation factor and the friction force on the seismic response of the tank.

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The purpose of this work is to show the mapping of a nonlinear dumping 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, numerical simulation for an three type asymmetrical nonlinear dumping vibration system.

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The estimation method of the damping properties for woven fabric composite materials has proposed. The proposed method has been applied to the plain woven fabric composites. Experiments have been conducted to evaluate the validity of the proposed method. It is recognized that the computational results have agreed with the experimental ones. -Next, it has evaluated the effect of angle of fiber bundle on material damping of plain woven fabric composites. The results show that the damping ratio is highest at angle of 45 degree.

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Viscoelastic materials are often used for solving engineering vibration and noise control problems. It is difficult to examine dynamic properties under high or very low frequency. Thus composite curves of dynamic properties are constructed by applying frequency-temperature reducibility to the experimental data. Much time and labor is needed for constructing composite curves of dynamic properties by manual. Therefore computer programs are needed to construct composite curves of dynamic properties. In this paper three kinds of algorithm for determining both shift and reducing factor are discussed.

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This paper proposes a numerical approach to the flow in the oil damper with a simple harmonic oscillation. Using the Finite Difference Method (FDM), the authors have analyzed the flow around the piston. The purpose of this work is to calculate the damping force acted on the piston of the oil damper. To this end, we first calculate the flow around a flat plate with a simple harmonic oscillation, and the solutions shows that twin vortices are generated behind the plate. Next, we compute the flow in the actual oil darner. The computation area is restricted to the space behind the piston.

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In this paper, a new type of viscoelastic-friction damper which gives damping in large amplitude range has developed. The damper consists of a shear-type viscoelastic damper and a friction damper connected in series. The trial damper was made and the resisting force characteristics were measured, and the parameters of a ten-element rheology model were identified. The frequency responses and seismic responses of a one-degree-of-freedom vibration system supported by the trial damper were measured using a permanent magnetic type shaking table. The experimental results are compared with the calculated results obtained by the FEM software and the effects of vibration suppression of the damper are discussed.

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In this paper, a new type of arm-type damper with two links and three joints (human type joints) has been developed. The damper is able to suppress six modes of vibration of a machine. The trial damper was made and the resisting force characteristics in the three translational directions were discussed theoretically and experimentally. The frequency responses of a single-degree-of-freedom system and the seismic responses of a three-degree-of-freedom system, which consist of a mass and four coil springs and supported by the damper, were measured using a three-dimensional vibration machine. The experimental results are compared with the calculated ones, and the effects of vibration suppression of the damper are discussed.

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Floor heavy impact sound caused by children's jumping in condominiums is a serious problem because there is no effective device to reduce it. In this study, a momentum exchanging damper was presented to reduce the impulsive vibration of the floor. This damper was composed of a spring, a dashpot and a mass, whose mass is contacts with the floor surface. When a heavy impact source falls on the floor, the momentum of that source is transmitted to the damper through the floor, so the momentum of the floor could be absorbed. Calculations and experiments were achieved to verify the effectiveness of the damper. It can be concluded that the damper significantly reduces the first vibration mode of the floor and reduces the vibration of the floor and the transmitted force to the slab.

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The authors proposed a single type self-powered active vibration control, in which an actuator produces control force with regenerating vibration energy and does not need energy supply. Previously, this system was applied to an active anti-rolling system for ships and its feasibility was discussed through numerical simulations and experiments. In this study, the authors propose to apply it to a vehicle suspension and examine its feasibility on a typical half-car model. The results of numerical simulations indicate the proposed system can reach better isolation performance than passive and semi-active control under the condition that the regenerated energy exceeds the consumed energy.

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This paper proposes a control system using dynamic forces between 4 wheels and road to improve vehicle handling and stability under severe driving conditions using yaw moment generated from the distriution of braking forces of four tyres (DYC). First, we propose a nonlinear 4-wheels vehicle model. And the longitudinal motion, the lateral motion, the yawing motion, and the load shift are taken into consideration in the proposed analysis model. In addition, nonlinear caracteristics of tyre are also taken into consideration by Magic Formula function. Then we design control system using model matching control method. In order to confirm the effectiveness of this system, the computer simulation are conducted.

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The present paper discusses the drivingbreaking force distribution for direct y aw-moment control (DYC) of the independent steering vehicle. The objective function is the maximum value of the tire workloads. In the case of conventional four wheel steering vehicle, the algebraic expression of the optimum drivingbreaking force distribution has been already deriv ed by the authors. Based on the results, the optimization algorithm for the independent steering vehicle is newly developed. For the front independent steering vehicle, the binary search is employed, and this is combined with golden section search method for the independent four wheel steering vehicle. Their convergence are guaranteed by the convexity of these optimization problems. Numerical simulations with CarSim, a popular multi-degree-of-freedom vehicle model, are performed to prove effectiveness of the proposed control scheme.

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This study aims at a system to measure 6 force components acting between a tire and the road surface by measuring strains in the wheel of the tire module. The measurement method was developed based upon the least square method. Dynamic test were carried out, showing effectiveness of the method. It is expected that the real time measurement of the 6 force components will greatly improve performance and reliability of the vehicle dynamics control systems.

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In this paper, a design method of a hybrid system for active steering based on model reference adaptive control is proposed. A controller to track a desired yaw rate is applied to a linear model because a driver is conscious of a yaw rate in normal situation. The controller is switched to a nonlinear controller to track a lateral acceleration because of the importance of lateral movement in critical situation. The timing of the controller switching is considered for the proposed model reference control system. Some simulation results show the capability of this hybrid controller.

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The hybrid electric vehicle (HV) has frequent internal combustion engine start/stop. Reduction of an uncomfortable vibration occurred at the engine start/stop period is desired. This paper presents the vibration reduction control method using a traction motor in the HV. The vibration reduction control method is designed based on the state equations of the HV drivetrain and reduces torsional vibration of the drive shaft. Experimental results with the HV prove the proposed method can reduce the vibration and achieve good driveability.

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Stability of Two-wheeled vehicles depends on their running speed. The running vehicle at high speed is stable but the vehicle in a state of stillness is unstable. In order to stabilize Two-wheeled vehicles in the state of stillness, center-of-gravity movement and handle operation by the rider are indispensable. Then we develop a stationary self-sustaining Two-wheeled vehicle which is a two-wheeled vehicle equipped with a cart system to move a center-of-gravity of the vehicle for stabilizing the system. We derive a state space model of system based on Lagrange method and identified model parameters by control experiments. A robust attitude controller is designed via Loop Shaping Design Procedure (LSDP). Experimental results show an effectiveness of the derived mathematical model and the designed robust attitude controller compared with LQ controller.

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Recently, many studies on vibration control using active suspension systems or semi-active suspension have been carried. Many studies analyze a one-car train model that assume velocity of vehicle is constant. In this paper, a five-car coupled train model that consider change of velocity of vehicle is considered. Random rail irregularity are generated artificially from a rail irregularity PSD. It is transformed to consider change of velocity of vehicle. In control design, H_∞ control is employed. Particularly, possibility of gain-scheduled H_∞ control that scheduling parameter is velocity of vehicle is examined.

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The magnetically levitated conveyance system to convey products without degradation of quality due to contact is investigated. Especially, we consider the magnetically levitated conveyance only with the vertical direction control to decrease the complexity and the cost of control system. The magnetic force of this system is obtained by assuming magnetic paths and calculating total permeance of them, and approximated by power series nonlinear magnetic force model. Then, we stabilize the dynamic unstability of the levitated system with the feedback of horizontal state variables. Finally, we consider the magnetic levitated system without the sensor for horizontal direction, and also stabilize this system using state observer for the horizontal state variables.

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This paper describes fixed quantity supply of the work by intermittent vibration transportation. Generally, since the damping ratio of a vibratory machine is very small, even if stops forced vibration, vibration is not damped down immediately, and supply of work continues for a while. Then, it enabled it to perform the quick growth and stop of vibration of a vibratory machine by feeding back the velocity of a vibratory machine. Consequently, fixed quantity supply of work was able to be performed correctly. Moreover, since the number of times of intermittence was increased, production efficiency was able to be raised.

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This paper describes the separation and transportation of works with various friction coefficients using elliptical vibration. Elliptical vibration machine has a horizontal vibratory system and a vertical vibratory system. Transportation velocity is depends on amplitude, phase difference and friction coefficients. When a friction coefficient differs by form or material of works, transportation velocity is changed also including the direction of positive/negative, even if elliptical vibration machine has same amplitude and phase difference. Using this phenomenon, works with which different friction coefficients can be separated by transporting difference direction.

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This paper describes a method of motion control on the new hybrid AC servo presses and a practical analysis method for complicated linkage mechanism using vector method. The servo presses have both rotation mode and reversal mode. Therefore, operators have been able to select high speed processing and high precision processing in the press machine. Because of the nonlinearities in the linkage mechanism, the servo presses generate gear noise. We reduce the noise with optimal parameter adjustment, and developed simulation system of the presses. It is shown that analytical results agree with experimental results.

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In this paper, the acceleration patterns avoiding the residual vibrations in positioning control are presented. Such patterns can be realized by deciding the time interval between acceleration and deceleration to coincide with the damped natural period or some parameter that defines the shape of pattern to be adequate. Another. Method is the proper repetition of an arbitrary pattern. These strategies can be used at same time, so that they can be applied to the multi-degree-of-freedom systems to eliminate free vibrations with multiple frequencies simultaneously and they can advance the robustness of the system. These features were confirmed by numerical simulations.

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In this paper, it is performed to suppress the transverse vibration of elevator-ropes caused by the resonance with sway of high-rise building. The elevator-rope has the characteristics due to its flexibility and the variation of its length. And also a control input system to suppress its vibrations requires gaps between an actuator and the rope because of preventing its abrasion. Therefore, we apply the nonstationary sliding mode control to reduce its vibrations with compensating the influence of time-varying characteristics and spillover and also the nonlinearity as the gap of input system. The suppression performance and the influence of nonlinearity are verified through the numerical calculations.

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This paper deals with motion and vibration control for a flexible tower-like transportation system, taking account of uncontrollable vibration modes called drumming mode. When the transportation system is constructed symmetrically, these modes are appeared as uncontrollable ones. For controlling vibration of whole modes under consideration, a structural modification in the design stage is carried out. Applying a lumped. Modeling method presented by Seto and LQI-based control system, two controllers are designed which achieves good performance for controlling motion and vibration in the flexible transportation system.

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In 3-dimensional sound field, it is difficult to control noise in whole area. Instead of whole area control, the controlled area can be followed to people in that field by new approach proposed in this paper. In the proposed algorithm, FTP algorithm that has fast converging property is introduced to a direct adaptive algorithm which does not need an error path characteristic. A numerical simulation is carried out with a sound field that the error path changes during control. From the results of the simulations, the effectiveness of the proposed algorithm is shown.

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The control system driving the vibration absorber with the force proportional to the velocity of the primary structure is unstable. This problem can be solved by implementing a target absorber equation that can be obtained by replacing the eigenfrequency of the original absorber equation by arbitrary frequencies of excitation and treating the squared arbitrary frequencies as an operator -d^2/dt^2. In this paper, this idea is applied to the active noise control experiment by considering a control speaker an absorber. The effectiveness of the present control method in controlling plural acoustic modes excited by broadband excitation is demonstrated by experiments.

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The concept of the active sound cancellation control of the railway wheel/rail noises by the On-vehicle-type devices is presented. And the apparatus of randomly exciting 60kg rail by the electromagnetic shaker which is enclosed with the panel system simulating the floor/side wall of the railway car was constructed. Further, one unit of the devices which realizes in principle the sound cancellation control of the see-through space was manufactured and the parabola-microphone and actuating speaker was installed on it in addition to the controller consisting of the analog electrical band-pass filter circuit group. And it was verified that the sound cancellation control effects are observed actually for the both cases of a speaker and the randomly excited rail system which were regarded as the primary sound sources.

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The active sound absorbing device unit of the transmission noise through a thin plate using a plate plane-wave speaker as the secondary sound source was developed and its lightening and compacting construction methods of elements was examined by trying the various combinations of elements. The controller is designed on the basis of the Filtered-x LMS adaptive algorithm by using DSP under the condition that the thin plate is subjected to the band-limited white noise. It was verified by the actual control experiments that the improvement from the view-point-of lightening of the unit is attained as a whole by the passive insulation effect of the speaker elements in addition to the active sound absorbing effect in comparison with the case in which a plane-wave speaker consisting of the piezoelectric film was used.

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This report describes the active control systems for reducing floor impact noise. The control system is comprised of actively controlled modular thin plates, which wholly cover the surface of concrete slab structure in the ceiling, and in each of which the mechanical vibration is controlled independently with electro-magnetic actuators. The final target is to commercialize the proposed active control system, but presently the development is going on. In order to achieve the target, construction of a simplified robust feedback control or an output feedback control is investigated in the following report. To prepare for this investigation, derivation of the dynamic model is pursued basing on analytical modelling.

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This paper describes the feedback control systems of active modular panel systems for insulating floor impact noise. The feedback control system is constructed with five sensors of the vibration acceleration, and five actuators of the electro-magnetic type and the digital controller, which means MIMO control system basically. In order to decrease the computing load of the controller, the decoupling technique of the natural modes of vibration in the panel is applied. An individual SISO controller is constructed for each of decoupled natural modes. Each mode is controlled simultaneously by parallel driver for each controller. We show effectiveness of the proposed control methods with the results of experiment, and now we develop a suitable controller with the micro computer comparing computing loads between MIMO control system and SISO parallel control system.

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Steel railway bridges characteristically tend to generate high-level structure-borne noise. It is an urgently required for railways, therefore, to decrease the vibration and noise of steel bridges. To develop effective countermeasures against this problem, it is important to study the noise generating mechanism and establish a method to predict the noise of steel bridge. The authors developed a new method for this purpose by combining the analysis of flexural vibration of plate based on the Rayleigh-Ritz method and finite element analysis method (FEM). The former is effective to predict vibration in a wide frequency range of including very high areas but doesn't suit the vibration analysis of a structure as a whole, while the latter dovetails the former in performance.

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In recent years, the noise caused by corrugated narrow-gauge wheel tend to increase compare it to a conventional wheel. It is assumed that the wheel is easy to occur lateral vibration because the thickness of side plate of the wheel becomes thin. We carry out the analysis to investigate the sound radiation of the wheel using 3D-FEM analysis, modal analysis, and sound intensity method. As the result, we found that the frequencies of the main modes are 1506Hz, and wheel vibration has close relation to sound power. Furthermore, the solution obtained by the FEM analysis agree well with the solution obtained by the experiment.

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This paper describes the approximate vibration analysis of thin plate with a hollow. The approximate vibration analysis uses a finite element model of thin plate with beams at the position of the hollow's edge in exchange of finite element model of thin plate with a hollow for finite element analysis. This paper defines adding beam's dimension as flexural and torsional rigidity equations. The equations are based on values of flexural and torsional rigidity that natural frequencies of both thin plate with hollow and thin plate with beams are the closest. In the next, this study applies the proposed approximate vibration analysis to optimization of the hollow' s position. And availability of this method is cleared by the point of computation time and concordance of optimum solutions.

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This paper describes the optimization method to reduce sound power radiating from a peripherally fixed thin rectangular plate by adding a rectangular hollow. The sound power at the fundamental frequency of the plate was set as an objective function. The location and size of the hollow were set as design variables and were optimized with the Feasible direction method.To improve the estimation error, the modal damping ratios after the structural modification were estimated based on the assumption of proportional viscous damping. The sound power radiating from optimized plate with the estimated modal damping ratio reduced by 5.3dB.

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This paper deals with a design of the crowning to reduce the ball passage vibrations of a rolling guide with the crowning length L_C(1.2s<L_C<1.7s, where s is the distance between the adjacent balls in the load zone). First, a fundamental condition to reduce the ball passage vibrations was provided. Second, a design method of the crowning by applying an approximate curve (an assumed functional formula) to the control points (satisfying the fundamental condition or being the intersection of straight and crowning areas of a raceway) was presented. Third, the design procedure was explained by giving an example. In the example, the power function crowning was nearest the control points. In addition, the calculated amplitude for the power function crowning was lower than those for the circular arc crowning and the crowning of the commercial rolling guide. Finally, the validity of the presented design method through experiments was confirmed.

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Four legs animals automatically choose the most efficient gait pattern according to the walking speed. This paper describes the mechanism of this automatic selection of gait, from the view point of the natural vibration mode. Then rigid body link model was made and analyzed, by simply modeling quadruped walk,. The results have shown that the mode shapes of this model are the same gait as animals walk.

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In this paper, a two-link flexible arm is introduced as a modeling object. The aim is to establish a new modeling procedure by combining to arms, which are independently identified. The change of boundary condition by combining them is expressed by using constraint addition method. The capability of proposed modeling method is investigated throughout computer simulation.

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In recent years, the space robot which does various works with the manipulator has been studied actively, in order to cope with various problems in astronaut's activities outboard. Unfortunately, the motion of a space manipulator causes disturbance to the spacecraft, because angular momentum is conserved in space. In this paper, based on the Kane's dynamical equation and an approach of multi-body dynamics, motion analysis is done in consideration of conservation law of angular velocity to built an equation of motion of the space robot in three-dimension, which is a first-order nonholonomic system. We show that our proposed algorithm is applicable to any tree-structured space robot by carrying out simulation for a cat robot.

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This paper deals with the numerical simulation of an axially moving sheet coupled with nonlinear fluid force. We clarified the nonlinear instability behavior of the axially moving sheet subjected to leakage flow. As a result, the fluid force becomes nonlinear with increasing flow velocity, and flutter occurs to the elastic body in the case of pinned-free condition. In the case of pinned-pinned condition, not only flutter but also divergence occurs to the elastic body. The flutter amplitude increases steeply, and the flutter frequency becomes higher with increasing the fluid velocity.

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Dynamic simulation of flexible multibody system with the hydraulic drive is presented for the digging operation of the hydraulic excavator. The energy saving technology is required on the construction machinery design from the present environmental point of view, and the dynamic simulation is useful for the energy saving evaluation. The digging operation of the hydraulic excavator involves the dynamics of linkage system and the hydraulic drive system that includes nonlinear characteristics such as the check valve and so on. New numerical analysis method is presented for the coupling system of the linkage system and the hydraulic system, which consists of the time increment prediction method on piecewise-linear characteristics and the bisection method in Newton method. It is shown that this method is useful for the dynamic simulation of the flexible multibody system with the hydraulic drive by appling to the simulation of digging operation on the hydraulic excavator.

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This paper deals with two types of trajectory planning method for three-link flexible arms. By using the desired trajectories obtained by the proposed methods, the flexible arms can rotate from each initial position to desired locations in given movement execution time without large troublesome vibrations. And additional feedback control devices besides the controller of existing actuators are not necessary. In order to confirm the effect of the desired trajectories on reducing the vibrations of the flexible arms, the responses of the three-link flexible arms were simulated numerically. It can be seen from the numerical results that the vibrations of the flexible arms were reduced enough by using the desired trajectories.

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This paper develops an analytical model of curtain-cable by using finite segment formulation and deals with numerical simulations of dynamic behavior of curtain-cable subjected to impact load The dynamic behavior of the curtain-cable is examined and discussed by the numerical simulations and experiments. The curtain-cable is stretched by external step load and the internal force generated at the girder end of the curtain cable is examined As a result, it is found that fee internal forces generated at the girder end of fee curtain cable increase with decreasing the length of the cables, and the numerical simulations are in good agreement with the experimental ones.

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