Two kinds of semi-active sloshing suppression control methods for the contained liquid in the vessel are presented. The sloshing suppression control algorithm of both method harnesses the switching two natural frequencies of the system in response to the sloshing status in the vessel, which provides the vertical bulkhead in it so as to divide the vessel but communicate at the bottom. The efficiencies of two presented semi-active sloshing suppression control methods are examined with numerical simulations.

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Sloshing suppression effects of vertical baffle plates installed inside a cylindrical tank are tested through computational fluid dynamics. Frequency responses and seismic responses by 2003 Off-shore Tokachi Earthquake are simulated about two distribution patterns, plates stuck out on the side wall and that interrupting the free surface. Frequency responses show both patterns increase the damping and free surface plates reduce the participation factor. Free surface plates have an advantage over side wall plates and reduce the maximum seismic response by about the half of the original, factors of which are explained by modal parameters obtained by the frequency response.

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In recent years, the importance of the fracturing test using the full-scale model is recognized in order to upgrade an earthquake resistant design. It is, moreover, important to develop a new measurement method which can measure a complex three-dimensional behaviour in such fracturing test. This study has been doing research and development of three-dimensional measurement method using an image processing technique for a measurement of dynamic displacement in shake table test without any contact. This paper describes the measurement results of shake table test using actual wooden house model in the largest shake table facilities at E-Defense, and evaluates synthetic measurement performance of the developed measurement system.

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An active vibration control device of a multistory structure is usually set up at the top of the structure. The device has aimed to suppress the primary vibration mode chiefly. However, a variety of frequency modes are included in the earthquake wave. Therefore, when a lot of frequency modes to make the secondary mode excited are included, the secondary mode is excited compared with the first mode. In this paper, it is considered to improve the control performance of the primary mode and the secondary mode with one active vibration control device set up at the top of the structure according to the vibration frequency of double-layered structure by the simulation and the experiment.

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A new device for reduction of seismic response of mechanical system is developed. The device is friction bearing which consists of upper and lower plates with spherical concaves and sandwiched spherical metals. Seismic response is reduced by friction between plates and metals. The device is shaken by the shaking table. Acceleration response of upper plate is measured. The maximum values of the response and the excitation, sum of squares and Fourier spectrum are obtained. It is concluded that the repose is significantly reduced. The device is applied to console rack. An analytical method is shown.

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The purpose of this paper is to estimate the real time vibration control of an actively-controlled nonlinear structure due to non-stationary external loads. When the optimal control theory is adopted as a control law against the concerned task, the derivation of time dependent optimal control gains may be required because of a remarkable non-stationarity of response amplitude. In addition, since the system is nonlinear, it takes more time to calculate those time dependent gains. This means that it is difficult to strictly execute the real time active control with optimal control theory as for the non-stationary and nonlinear system. In this paper, therefore, one approximate technique, coupled fuzzy-optimal control, is proposed in order to realize the real time control of non-stationary and nonlinear system. Finally, results by deterministic analysis based on numerical simulations are compared with those by stochastic analysis using statistical equivalent linearization technique.

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This paper proposes the device that can preserve the vibration energy as elastic energy. The proposed system that can store energy is composed of a spring and two variable dampers used by semi-active control in vibration control. A spring and a variable damper are set up in parallel, and a variable damper is installed to it in the series. In this study, the basic algorithm is proposed to store the vibration energy as elastic energy in the first natural frequency and excite the main system in other high frequency by the stored energy. Finally, effectiveness of the proposed system is confirmed by the simulation.

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The authors have developed four kinds of techniques on electrostatic classification of particle size utilizing the balance of the electrostatic and gravitational force. The first is an inclined plate conveyer system. The plate conveyer consisted of parallel electrodes. Four-phase traveling field is applied to the electrodes to transport particles. The second is an inclined tube conveyer system. The third is a vortex electrode conveyer system. The last is the combination of the plate conveyer and an electrostatic separation roller. These techniques are expected to be utilized to the classification of toner and carrier particles used in electrophotography.

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This paper presents the development of a sensor system for collecting tactile information. First, distinction examination on six kinds of fabrics is done through human tactile perception. Next, an active sensing system using the piezoelectric effect and the pyroelectric effect of a PVDF(Polyvinylidene Fluoride) film is fabricated. The sensor's surface is heated and two kinds of active sensing, contact and slide, are introduced. Measurement using the sensor system is done on the samples. Comparison between the sensor outputs and the results of the distinction examination shows that the sensor system extracts features on feelings of vibration and warmth.

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A print defect of streaking took place in an offset printing machine after ditches of blanket drums collided with those of proof cylinders. The streaking was visible just after the collision. These experimental features suggested that the defect was caused by the vibration of blanket drums and proof cylinders due to the collision of these ditches. This hypothesis was proved by the experiment that the pitch of streaking coincided with the period of the vibration. The experimental results were confirmed by the numerical calculation based on a simple linear vibration model of eight-degree-of-freedom.

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This paper is a report of the research of an energy storage flywheel system with a flexile rotor used for an electric car. After introduced the energy storage flywheel system, the parameters of the rotor and the flywheel are decided by the vibration analysis of ANSYS. Based on the vibration analysis results, the model of the rotor and the flywheel is designed. In order to simulate action of a car, a moveable foundation is designed. Then robust controller of the rotor system and the foundation are constructed respectively to decrease the noise from the foundation. Form the simulation results; we verified that the proposed model and the controller are effective for the energy storage flywheel used in an electric car.

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In this research, it proposes a magnetic damper that uses the magnetic repulsion type bearing where the magnetic repulsion power was used and magnetic repulsion and the absorption force as a method of doing the vibration control of the Superconducting Flywheel system that uses the magnetic gradient drive method. When the levitation body vibrates, the voltage in proportion to vibration velocity from the sensor coil is fed back with the magnetic bearing and the magnetic damper. As a result, the magnetic bearing and the magnetic damper generate damping force for the levitation body. In addition, the damping force does the vibration control of the whip vibration and the pitching. The magnetic bearing and the magnetic damper are made for trial purposes, and the usefulness of the dumping control to the levitation body is confirmed by the experiment. Furthermore, a comportement analysis were done.

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This research investigates nonlinear dynamics of a beam supported at its both ends by electromagnetic forces from High-Tc Superconducting bulks. Experimental results show some resonance of an asymmetric mode consisting of pitch motion and deflection, which does never get excited in a symmetric linear system. It is a kind of parametric resonance. It shows soft-spring response: as the amplitude increases, the resonant frequency becomes small. Numerical results also show parametric resonance of the asymmetric mode. Mechanism of this resonance was discussed from nonlinear coupling of the eigenmodes.

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Generally, the laser sensors or eddy-current sensors have been used for sensing devices of magnetic levitation system, and recently, the Hall element is used for the sensor of magnetic levitation. However, the conventional studies using Hall element considered only the one dimensional vertical position of levitated object. In this paper, the two-dimensional displacements of levitated object using two Hall elements are proposed and discussed. The validity of proposed method is confirmed by experiment.

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A vibration suppression device is presented for a grass cutting machine driven by an engine. Since the machine is portable, it should be light and compact, in addition, engine vibrations and their transmissibility to the human body should be small. It is difficult to suppress both engine vibrations and its transmissibility to the body simultaneously by using usual vibration control technique. By suppressing both, this article applies an anti-resonance control. In order to create the anti-resonance, a new type variable spring magnetic vibration absorber is developed, and its control method is presented. Since the important frequency region of the machine is in the second mode, a new control technique is presented for suppressing second modal vibrations using the absorber. Theoretical analysis is given, and experimental check is also performed to validate it.

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This study is the development of new float polishing technique utilizing magnetic compound fluid(MCF) that has been developed as one of magnetic responsive intelligent fluids by one of authors. The float polishing technique has large gap between the polished and polishing surfaces and carries on the mirror finished flat surface. Various factors with the effect on the float polishing were shown, for example, the types of polishing tool with magnet, the float polishing style with both motion of the polishing tool, the rotational speed, the kind of the polished specimen, and et al..

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Bicycle is one of the most familiar vehicles in daily life, but it is a well-known unstable system in itself. Although there are two methods of steering a handle and moving a weight in order to make a bicycle stable, it is shown that the former is more effective than the latter. This study deals with modeling and stabilizing control problems of a two-wheel bicycle. In the modeling, wheels side slip is taken into consideration. In the control, an optimal feedback control for stable running control is obtained. An autonomous bicycle robot is further developed. As a result of experiment, it is shown that the bicycle robot is able to run straight and turn stably. The effectiveness of the two-wheel bicycle model and control law are demonstrated.

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A SSM(Sensor Steering Mechanism) vehicle achieved high-speed moving on a straight-line and high accuracy following the guideway of the road. The previous paper proposed the variable lever ratio (the ratio of the arm angle and the steering angle) and steering ratio (the arm length ratio based on the wheel base) in order to increase the moving speed by the generated trajectory. The SSM vehicle reduces the slip angle of the tires at the corner of the course, and the moving speed of the SSM vehicle is increased. This study estimates the lateral control characteristics of the SSM vehicle with 1kHz smart camera which is moving on S-curves. The S-curves are set the turning angles 45o and 90o for the test course. Finally, the simulated results show the advantages of the variable SSM.

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This paper describes a new type of a vehicle mechanism using in greenhouse. The feature of this vehicle mechanism is that normal tires use for front wheels and rotary crawler system for rear driving mechanism. As the passage in greenhouses is very narrow and bad to move, turning and passing performance is important. More over, the vehicle is developed as a part of automatic harvesting system in greenhouse, so simple turning operation and robust passing ability are required. In this paper, mechanism of the proposed vehicle, strategy of turning, comparison with other type vehicle is explained.

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Quadrupedal locomotion form changes depending on the passing speed. Locomotion form at maximum speed is called a gallop. Also, it can be considered that gallop corresponds to continuous jump. Recently, the development of the animal type robot is widely carried out. However, the quick and smooth operation represented for the jump operation is difficult in conventional animal type robots. The animal can jump easily compared with robots. It is because there is bi-articular muscle, which affects two joints simultaneously, that the robot doesn't have on animal's leg. In this study, the jump mechanism, which imitated the animal muscle arrangement, was produced experimentally.

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It seems that the emergence of intelligence in an autonomous robot exists in the dexterity of human or creatures as complex systems and the research style and the development procedure along this approach should be necessary for realization of a real intelligent robot. This paper realized the simple autonomous shock avoidance during falling down and instantaneous rising of biped robot GENBE with Anti-ZMP based on distributed control of physical body in a martial art utilizing instability.

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Hand posture estimation is important to realize a high accurate gesture interface and has been studied extensively. However, most of conventional gesture recognition systems require high computational cost to estimate hand posture. This paper proposes a new model-based method. First, we estimate the joint angles based on hand model in the method. After that, we construct a reduced-order space for the measured angle by using PCA(Principal component analysis), which is used to recognize the hand posture. Then, our proposed method makes it possible to reduce the computational cost and noise. We confirmed that our experimental system can recognize gestures in real-time and be applied for robot manipulation.

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This paper describes improvement of recognition system for picking robot of sweet pepper in greenhouse horticulture. The improved lighting system substituted LED for fluorescent that was located around the CCD camera. In the result of experiments, the LED lighting system was unlikely that recognition is wrong because the lighting area is limited to the small area by the LED lighting system.

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This paper presents a design procedure of H_∞ controller for motion and bending-torsional coupled vibration of flexible robot arm. In the case that the robot arm does not hold the inertial center of the payload, it processes uncertain bending-torsional coupled vibrations which affect in the accuracy and the stability of the controller. In this research, H_∞ robust control design scheme taking account of parameter variations as structured uncertainties is utilized to describe the uncertainty in coupled vibration to guarantee robustness against such uncertainty. The superiority of the presented controller design method is certificated.

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Analitical solution of the inverse kinematics has been found only for some particular structures of 6-DOF serial manipulator. We propose the Method of Sequential Retrieval by modifying the Effective Solution for Inverse Kinematics to solve the inverse kinematics for a 6-DOF robot arm which has not been analytically solved yet. We confirmed that our method can find some solutions which can not be solved by the Effective Solution for Inverse Kinematics. Moreover, we presented the effectiveness of our method by comparing its convergence speed with that of the Newton-Raphson Method.

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In this study, 1st link set in the side supporting an arm is a rigid body, and 2nd link set in the tip side is a flexible arm. The flexible arm of the 2nd link is assumed to be the rigid body arm which consists of 2 links using a virtual joint, and the control object is modeled with the rigid body arm of 3 links. Moreover, the contact force at the tip is modeled with a spring and a damper. The Hybrid Control system of the position control and the force control is designed to this model. The force control system is designed by the Sliding Mode Control system, and the validity of the proposed control method is examined by simulations and experiments.

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In this paper we deal with a global optimal design of dynamic parameters of robot manipulators. The dynamic characteristic of robot manipulators is uniquely determined by base parameters, which are functions of physical parameters, e.g., the mass, the moment of inertia and the damping, etc. of each link, not by those physical parameters themselves. Using the fact that the equation of motion of manipulators generally becomes an affine function on the base parameters we propose an LMI based optimal design method of the base parameters of robot manipulators. We minimize the energy which is required to achieve a given task of manipulators. The proposed design method guarantees the global optimality of the optimized base parameters. A design example is shown in the case of a optimal design of the base parameters of a planar two link manipulator which is controlled by computed torque method.

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In this study, we proposed a biped robot capable of walking on the level ground based on passive dynamic walking by actuating motors embedded only in ankle joints. It was demonstrated that the robot stably walked down a small decline without the use of any motors. Because this robot was built by not only considering the characteristics of natural human walking but also actuating the motors to resonate with the period of its passive dynamic walking, it is possible to walk like a human-like gait and high energy efficiency.

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This study aims at finding active biped robot designs with efficiency and simplicity of passive-dynamic walking. In this paper, a control method based on passive-dynamic walking is proposed. Torso and swing-leg control enable a biped robot with knees on level ground to walk stably without gait planning. The torso control is used to generate active power replacing gravitational potential energy which is used in the case of passive-dynamic walking. The swing-leg control is applied in order to satisfy the transition condition of the swing-leg and the stance-leg before the robot falls down. When we choose an appropriate parameter of the swing-leg control, the biped robot can walk stably and efficiently over a wide range of speed.

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This paper deals with development of a passive/active united actuator and it's application to a biped walking robot. In order to achieve an effective walking of a biped walking robot, it is required to unite the passive walking and the active one. Thus, a passive/active united actuator that has a torque detector and is actively controlled with our zero torque feedback control method was firstly developed in this paper. Proposed control scheme includes the passive walking period and the active walking one. In the passive walking period, the self-excited walking control is also employed to control the swing leg.

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It seems that the emergence of intelligence in an autonomous robot exists in the dexterity of human or creatures as complex systems and the research style and the development procedure along this approach should be necessary for realization of a real intelligent robot. This paper realized the simple self-sustained humanlike robust instantaneous NANBA TURN about body axis of humanoid biped robot GENBE based on distributed control of physical body in a martial art utilizing instability with Anti-ZMP, which uses only small active power with simple chaotic limit cycle using gravity.

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The force acting on a machine or a structure must be identified when they are designed or in case of condition monitoring and diagnosis. One of the force identification methods is based on the equation of motion, in which the responses of all degrees of freedom are estimated from the measured response data using modal analysis technique. The method is very useful for rotor systems but there is a problem that the identified force is distributed over the structure in case of unique structure. In this study, the identification method is improved, in which the accurate responses can be obtained under some constraints. The method is numerically and experimentally checked and it was shown that the method was useful for actual application.

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The force acting on a machine or a structure must be identified when they are designed or in case of condition monitoring and diagnosis. One of the force identification methods is based on the frequency response function. The method is very useful although it requires the information of location of force acting. In this study, the identification method is improved such as to apply the case with no information of location of force. The method is numerically checked and it was shown that the method was useful in the case without noise in the measured data.

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The time reversal processing for the measured sensor signal can be applied to detect not only structural damage but also impact loading of the structure. The impact identification capability of a time reversal processing using experimentally measured sensor signals is demonstrated in this paper. After measuring the electrical sensor signals corresponding to scattered wave filed of the plate in experimentally, the time reversal processing is applied to the measured signals in the numerical wave back propagation simulation for localizing the impact loading point on the plate. The time-reversed wave travels back through the plate and is focused on the region around a point where hit by the impact hammer. The illustrative experimental and numerical results demonstrate impact identification capability of the proposed impact detection method.

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It is very important to detect the occurrence of a crack on rotating machinery in early stages. In this study, dynamic characteristics of a cracked rotor with a excitation force using active magnetic bearing(AMB) are investigated. Due to the open-close mechanism of the rotor crack, the equations of motion of a cracked rotor have linear and nonlinear parametric terms. When a harmonic electric current is applied to AMB and sweep its frequency, various kinds of resonances, which are not observed in a symmetric rotor and an asymmetric rotor with linear spring characteristics, occur due to the unique spring characteristics of a cracked rotor. We clarify characteristics of these resonances theoretically. Furthermore, obtained theoretical results are validated by experiment using the rotating shaft system with actual fatigue crack.

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Vibration tests were performed to validate two proposed methods of estimating vibration-induced stress, respectively. One was for simple small-bore piping and the other was for complex one. The tests were performed using sine wave or random wave or the field response wave measured on-site. As the former results, the calculated stress using first proposal method showed better agreement with the measured stress than using traditional one. As the latter results, the estimated stress using the second proposal method became to be from 0.5 to 2 times to the measured one.

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We develop technology to measure vibration of a shaft in the inside of double pipes by a ultrasonic wave to monitor shaft vibration of vertical pumps having a pipe in the inside of a column pipe. By the tests using a mock-up which simulated a pump column pipe, it was confirmed that ultrasonic wave from the shaft in the inside of a double pipe was received and that shaft vibration was measured.

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A compressor is an important element in equipment. Because equipment has problems if it decrement performance or seize-up, diagnosis system (especially CBM) is needed. This investigation focused on a reciprocating compressor, modeled the compressor body and failure, and examined characteristic changes and the way of fault place identification. From a simulation result I could understand a characteristic in an epidemic and was able to distinguish three kinds among five kinds of abnormality.

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In the present state of maintenance on cogeneration systems(CGS), simple diagnosis technique is often used. To make CGS operate with higher reliability and more efficiently, the diagnosis system is necessary. To develop the good diagnosis system, the load and outside temperature etc. must be considered and the damaged element could be identified. In this paper, we build the CGS model with thermodynamic and kinetic characteristics, and examine the diagnosis technique to identify characteristics of systems with and without damage.

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The diesel engine has a high thermal effiency, but the serverity of emission restriction is increasing. In such a circumstance, various exhaust decrease devices is studyed. But several exhaust device is affected by a fuel property. In this study, we examined possibility of fuel kind distinction by mutual unit type neural networks work system using diesel fuel, kerosene and heavy oil.

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In traffic accident judgment, accident is reconstructed to investigate the cause from the state of vehicles and the situation of the scene. This is one of the inverse problems which find a cause from a result. Now, reconstruction of accident is executed by top-down technique which using estimated value by the intuition from experience of an appraiser. However, this method will be influenced by an individual appraiser's ability. So, in this research, vehicle movement is reconstructed by neural network, whole state of phenomenon is prescribed by the chain function based on simple rule, instead of top-down technique.

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This paper describes a new fault detection method using the sliding mode observer. Required capabilities of FDI filters are sensitivity of occuring faults and robustness against disturbances. The FDI filter which proposed in this paper can estimate faults even if disturbances exist. An example is shown to demonstrate the its effectiveness of the method by comparing with conventional methods.

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We have proposed the thin plate type bolt loosening detection sensor. However, the sensor is too large for practical use, so that it is desired to miniaturize the sensor. In this paper, we propose slit cut thin plate type sensor as a miniaturized sensor and the oscillator circuit for natural frequency identification. The size of the slit cut sensor is smaller than the quarter size of the thin plate sensor. The oscillator circuit is based on positive velocity feedback and the oscillating frequency of the circuit coincides with the natural frequency of the sensor perfectly.

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In this paper, a sensing methodology to detect and characterize early damages such as loose bolts in a joint is developed. The proposed sensing system consists of PZT patches attached on the structural surface, one of which acts as a transmitter of ultrasonic harmonic wave. The incident harmonic wave is scattered by the damage and received by the other patches. When the structure is subjected to the operational or ambient load, it vibrates, and the inherent damages introduce some nonlinear effects into the structural dynamics. This nonlinearity is observed as the phase- and amplitude-modulation of the scattered waves due to the changes in the scattering characteristics synchronous with the structural vibration. By investigating the modulated phase or amplitude of the scattered wave, the nonlinear characteristics of the damages can be specified. Some experiments using a bolted beam are conducted for illustrative purposes.

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We are researching a flat belt with the self-diagnosis function that is called a Health Monitoring for the transportation equipment such as elevators. The labor saving of maintenance is achieved at by the Health monitor function, and the safety at the disaster is maintained. In addition, it has aimed to achieve conservation of energy and the miniaturization by changing to a flat belt. We proposed the shapememory alloy as a sensor installed in a flat belt, and did the experiment that confirmed the performance as the strain sensor of the shape-memory alloy.

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In this paper we deal with the active control of shock caused by the collision between two objects so as to make the deformation of shock-receiving object large and deformation of shock-giving object small. Because the shockreceiving object deforms elast-plastically, we appliy gain-scheduled(GS) control to overcome the discontinuous input when the deformation of shock-receiving object change from the elastic range to plastic range. Moreover we utilize varying gain of a frequency weighting function in order to improve performance of shock control. Evaluation index of effectiveness of control is the plastic deformation ratio between the two objects. By carrying out experiment, it is verified that the GS controller designed is effective for active control of shock.

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In this paper, we propose a shock reduction mechanism for a force control system such as a die cushion. An impact arises between an upper die and a blank holder, on the die cushion used for draw forming. A shock at the time of an impact is reduced by using soft springs by short stroke. Two impacts occur on the die cushion by choosing a suitable spring constant. And a optimal value exists in the spring constant. The proposed method is applied to a prototype of novel AC servo die cushion developed for the first in the world.

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In this paper, we deal with active control of shock in a collision problem between two objects by applying control input to the shock-giving object. The goal of active shock control is to suppress the deformation of the shock-giving object and make the plastic deformation of the shock-receiving object large. The deformation ratio is defined as ratio of the plastic deformation of the shock-receiving object to the deformation of the shock-giving object. By using LQI control allowing deformation of the shock-giving object, the controller is designed. It is shown from the results of simulations that there is the maximum value in the deformation ratio standardized by the input energy with the change of weighting coefficient for the control input.

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In a car crash, if deformation of occupant lung is held to the allowable value, no aftereffect will remain. In order to realize this condition, the active seat belt, which adjusts instantaneously the tension, has been proposed. In this study, the actuator which controls the tension using the friction is improved in order to suppress the overshoot of the lung deformation, and the effectiveness is confirmed by the control experiment using the scale model. As the result, the overshoot of the lung deformation can be suppressed to 20%, the deformation after the overshoot can be settled near the target, and the deformation rate can be suppressed to 1.6 times of the target.

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In this paper we propose an active knee bolster to defend passenger legs in vehicle collision. Although it is possible to decrease the load to the passenger legs in vehicle collision by using a passive knee bolster with an elast-plastic element, the active knee bolster may be adaptable to the various situations of the collisions. In order to suppress the contact force between the passenger knee and the knee bolster, Linear Quadratic Integral(LQI) control is applied. By carrying out simulations, it is verified that the active knee bolster is more effective than the passive knee bolster among wide range of collision speed.

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