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In this study, the effect of loading rate on the strength and the absorbed energy of paper foam board was examined by a series of dynamic and quasi-static compression tests. For comparison, polystyrene foam board was also tested. In dynamic compression tests, a polyvinyl chloride (PVC) tube instead of an ordinary metal bar was used for the measurements of the load applied to the specimens, in order to relieve the impedance mismatch between stress bars and specimens. The absorbed energy up to a strain of 50% in compression tests of paper foam board is about 1.5 times greater than that of polystyrene foam board. It was also found that the absorbed energy obtained from dynamic tests for paper foam boards was about twice comparing with the results at quasi-static rates.

A new method of detecting the number of moving sheets without contact has been investigated. This paper deals with the development of a method of detecting the number of sheets of paper and cloth. This detecting method utilizes the variations of the phase of the transfer function of the entire acoustic system including the sheets. The impedance of sheets varies with their number. Thus the number of sheets shows good correspondence with the phase of the transfer function of the acoustic system. The experimental result shows that the number of moving paper sheets can be detected without contact, and also the number of sheets of cloth which are sufficiently clumped between the end face of the pipe and a rigid wall can be detected.

This paper deals with an environment recognition system which is suitable for small-sized autonomous exploration rovers working on a planet far from Earth. The recognition system consists of a scanning type laser-range-finder and attitude sensors. Because rovers equipped with the proposed system can continue to move on terrains, the system makes it possible for a small sized rover to traverse as a long distance as large rovers under a restriction on its limited mission duration. In this paper the performance of the proposed system is evaluated in both numerical simulations and experiments, considering the effects of sensor errors. Moreover, methods to evaluate estimation accuracy for environmental recognition techniques and to estimate the slip rate of moving rover in short time intervals are introduced.

Soil behavior generated by a root-cutting blade moving under the ground of an automatic spinach harvester for spinach for eating raw is analyzed in this paper. It is difficult to harvest spinach for eating raw by using automatic harvester because stems and leaves of spinach are soft and easily bruised. Thus the harvester which can be widely used among farmers has not been developed. To overcome the difficulty, we have been developing the automatic spinach harvester which does not bruise spinach. A trajectory of a root-cutting blade is very important to achieve this automatic harvesting without bruising spinach because the motion of cutting the root of spinach is influenced by soil which the blade presses and moves in. In this paper, accordingly, some characteristics in the behavior of soil caused by the moving blade are clarified by using the distinct element method (DEM) to investigate the automatic harvesting. In conclusion two important characteristics, the velocity of the moving blade and the volume of soil in the passage field the blade moved, are pointed out and described., 日本機械学会論文集. 81:15-00298- (2015)

Simple adaptive control (SAC) is known as a control method that keeps control performance even if plant properties have changed. However, there is a problem such that the vibratory output occurs in the transient response when SAC is applied to a vibration system which includes anti-resonance modes. This paper clarifies the reason and an improvement method of the problem. The reason why the vibratory output occurs is that the vibratory input corresponding to the anti-resonance frequency occurs by the structure of SAC. In order to overcome the problem, it is shown that designing of a parallel feedforward compensator (PFC) appropriately is effective. The PFC should be designed such that the frequency response of an augmented system which consists of the plant and the PFC does not have anti-resonance properties even if the plant includes anti-resonance modes. This paper proposes a PFC design method to overcome the problem such that the gain of the augmented system is matched to the one of a pre-specified desired model. Furthermore, the PFC must give the ASPR property to the augmented system. The design problem is described as an optimal problem of the frequency response matching under some restrictions on the ASPR property. The optimal problem is solved using the distributed particle swarm optimization which is effective for a non-convex problem. The effectiveness of the proposed method is verified by numerical simulations and experiments., Article, 日本機械学会論文集. 81(824):14-00474- (2015)

This paper introduces a novel direction-of-arrival (DoA) technique based on phase differences of electromagnetic waves. In detail, design and implementation issues for the DoA directional sensing are described, towards providing an efficient solution to mobile robot target tracking for various applications. What is the most important aspect from the practical point of view is how to realize accurate measurements of the bearing from an electromagnetic spot source. For the purpose, a DoA estimation model is proposed using a minimum number of antennas. Another focus lies in the implementation of an in-house DoA detection prototype considering the simplicity and generality of hardware configurations. This paper explains details of a purpose-built, cost-efficient solution ranging from the estimation model design to its hardware implementation suitable for autonomous robot navigation. Experimental results show that the proposed method for the DoA estimation and its hardware prototype can be considered quite satisfactory in an indoor environment.

金沢大学理工研究域機械工学系, In this paper, a sequential approximate multi-objective optimization procedure by the Radial Basis Function (RBF) network with the Satisficing Trade-Off Method (STOM) is proposed. The sampling strategy is an important issue in the sequential approximate optimization. In this paper, the density function and the pareto fitness function are proposed. The objective of the density function is to find the sparse region in the design variable space. New samplings point are obtained by optimizing the density function. The objective of the pareto fitness function is to find the approximate set of pareto optimal solutions from the given data. New sampling point is obtained by optimizing the pareto fitness function. Both functions are constructed by the RBF network. By using both functions, the approximate set of pareto optimal solutions can be found effectively even when the set of pareto optimal solutions are separeted. Through simple numerical examples, the validity of proposed sampling strategy is examined.

This paper describes a new type of magnetic suspension system using a rotary geared motor and a disk magnet. In this suspension system, the suspension force is provided by a disk-type permanent magnet and is controlled by a magnetic flux path control mechanism, which rotates the disk magnet to change the flux passing through the suspended object. This suspension system may realize zero attractive force to avoid the uncontrollable adhesion, changing the polarity of the stator poles for complex applications, and zero-power levitation with the constant air gap. In this paper, suspension principle and the experimental prototype of this proposed system are introduced, the basic experiments using the prototype are examined, and the modeling and simulation are carried out. Finally, some suspension experiments for verifying the suspension performance are executed.

Sewer pipes over 380,000 kilometers in total are existed under the ground in Japan. However,worn pipes have been increased and a number of subsidences of a ground caused by the collapse wereoccurred. Recently, the inspection of the pipe is executed by the moving cart with CCD camera. Currently human inspector judges the condition of the pipe by the images recorded by the CCD camera. It should be noted that the judgment by the human causes the individual variation since it depends on the person's sense. Quantitative measurement is required.In this paper, the 3D quantitative measurement system for a sewer pipe is introduced. Two parallel laser sheets are projected from the inside of the pipe and the two circular laser streaks appearedon the inside surface of the pipe are recorded by the CCD. The measurement of the crosssection is established by analyzing the recorded streaks. Amount of displacement between two circular streaks are used to detect the tilt of the system against the axis of the pipe. The pipe is reconstructed by stacking of the crosssectionson considering the moved distance and the tilt of the robot. The automatic calibration using a liquid crystal display is also introduced in this paper. The calibrationmethod reduces the lens distortion of a wide-angle lens and a high accurate measurement isestablished. Experimental result shows the feasibility of the system.

金沢大学理工研究域機械工学系, This paper addresses to develop a novel strategy to relax the adhesion forces for picking and placing operation in a micro range. In a micro range, the attracting forces such as the van der Waals, capillary, and electrostatic forces become dominating due to a scaling effect. The attractive forces cause the adhesion between the object and the endeffector. Therefore, it is hard to manipulate an object in a micro range. This paper shows that when an oscillating endeffector approaches to an object, the adhesion between the object and the oscillating endeffector can be reduced. Also, based on the experimental analysis, we clarify the relation between the oscillation and the pushing amount of the endeffector on the object, where the adhesion force can be released effectively. Using this relaxation method and the relation, we develop a strategy for picking and placing operation in a micro range. This strategy provides an accurate manipulation. Some experimental results show the effectiveness of this approach.

This paper presents a design method of a switching control algorithm in which the conservativeness is reduced in sliding-mode control. In a conventional sliding-mode control system, the control input is switched so that a certain function can remain a Lyapunov one in spite of the presence of system uncertainties. However, the switching gain with conservativeness is generally derived due to the simplicity of the control algorithm. In this case, higher gain is required than is necessary. This situation is not suitable since it causes chattering in system inputs and/or steady state errors in system outputs. In this paper, a condition realizing a Lyapunov function is newly derived. Based on this result, a novel switching control algorithm with reduced conservativeness is proposed. The algorithm is also expanded to an output-tracking control problem. Finally, simulation results are given to illustrate the effectiveness of the proposed switching control algorithm.

金沢大学大学院自然科学研究科知的システム創成, In practical applications, it is important to reduce the function evaluations in the simulation, and obtain the approximate optimum with high accuracy. To achieve these objectives, the integrative optimization system using the RBF Network (RBFN) and the Generalized Random Tunneling Algorithm (GRTA) is proposed in this paper. This system consists of three parts. (1) Construction of the response surface, (2) Optimization by the GRTA, and (3) Adding the sampling points. The RBFN is used to construct the response surface. The radius on RBFN, which affects the accuracy of response surface, is an important parameter. Firstly new equation for the radius is proposed, based on the examination of existing equation. Secondly a simple sampling strategy to obtain an optimum with high accuracy is also proposed. In general, the objective function and the constraints are approximated, separately. However, the optimum of response surface will often violate the constraints. To avoid such situations, the augmented objective function is utilized in this paper. Then the proposed sampling strategy is applied. Through typical benchmark problems, the validity and effectiveness are examined.

This paper investigates a calibration method of 6 DOF acceleration sensor system using multiple linear accelerometers. So far, it has been considered that a set of 6 DOF acceleration data is to be essential to its calibration. In this accelerometer system, 6 DOF acceleration can be resolved using the geometrical condition of 6 linear accelerometers. Therefore, the measurement error results from the alignment error of the 6 linear accelerometers. And so, we analyze the alignment error and give a caribration method to identify the error only using some limited linear accelerations (acceleration of gravity). This paper discusses its calibration method with experiments for our prototype 6 DOF accelerometer. The results show that the calibration using limited data is possible and has good performance.

This paper discusses the integrated design of structural shape and controller of high-speed positioning actuators for magnetic recording test stands. To allow highly flexible shape design of the mechanism for the positioning actuator and to improve the calculation efficiency in the structural shape optimization, this paper proposes an integrated design method in which a structural shape is defined like as a skeleton and meats and a genetic algorithm is used to search the combination of the skeleton and meats for obtaining better performance of the closed loop system in iterative design procedure. The iterative optimization procedure includes the shape and the controller updates. It is shown in design examples that the proposed integrated design method can improve the performance of the positioning actuator according to the performance indices, and the effect is verified.

The thermal transfer print method is to print ink on the surface of paper by pressurizing ink and paper directly with a thermal head, and heating the places to print. A principle of the thermal transfer printing is similar to that of the offset printing. A tribological contact problem occurs in the offset printing. Thus the thermal transfer printers are suffering from the similar contact problem between the ink and the paper since the surface of the plain paper has roughness and it is very difficult to make the contact situation constant at all time. It is necessary to deeply understand the contact between paper and the solid ink to achieve the high-resolution printing on even the rough plain paper. So far the stylus type and the laser type profilometers were used to evaluate the printing quality for various papers. However there is no attempt to examine the printing quality, optical density, from the view point of real contact area. Then, the relationship between the optical density and the real contact area on the paper side was experimentally obtained in this paper with a contact microscope. As a result, the correlation could be found between the optical density and the real contact area.

This paper is concerned with the development of an in-situ measuring device for evaluating the swelling/desweling characteristic of temperature responsive polymer gels by the piezoelectric admittance measuring technique. The device is a simple cantilever type transducer, which consists of an aluminum cantilever beam, a piezoceramic pathch and a probe coated with the polymer gel. The probe can be easily assembled to the cantilever transducer with a double stick tape. In the paper, the characteristic of the transducer is investigated first with the aid of FEM analysis method. Based on the simulation results, a prototype piezo-transducer and probe coated by polymer gels are made. The characteristic of the gel is tested in situ experimentally. The results validated that the water content in the gel can be detected simply by the transducer. Furthermore, two kinds of membrane coating methods were investigated. The results obtained by the proposed transducer indicate that the directly coated gel membranc has higher temperature response in the water content than the pasted gel membrane.

In this paper, we investigate a design method for multi-period repetitive controllers for nonminimum phase systems. Multi-period repetitive controllers were proposed by Gotou et al. in order to improve the disturbance attenuation characteristics of conventional repetitive control systems. Yamada et al. proposed a design method of multi-period repetitive controllers to attenuate widefrequency disturbances based on the idea of changing time-delay. Steinbuch proposed a design method of multi-period repetitive controllers for systems with uncertain period time. In this way, several design methods for multi-period repetitive controllers have been proposed. However, the parametrization of all stabilizing multi-period repetitive controllers has not been considered yet. In this paper, we propose the parametrization of all stabilizing multi-period repetitive controllers. Next, we present a design method of multi-period repetitive controllers using the obtained parametrization.

In this paper, we examine the anxiety at utilization of wheelchairs. When the human use wheelchairs, from the influence of environment, the human feel a sense of unease. The sense of unease is under influence of the organ of vision and the vestibular organ. In this paper, when the human croses slopes using wheelchairs and the influence of the organ of vision is eliminated, whether or not, the declivity angle for human to feel the anxiety can be estimated. It is clarified that the declivity angle for human to feel the anxiety can be estimated with relatively high accuracy.

In this paper, we examine a design method for decoupling control systems for non-minimum phase systems. The decoupled control system is the system that established one to one correspondence between input and output. Since the decoupled control system is considered as several single-input/single-output systems, the input-output characteristic of the decoupled control system is reduced to the single-input/single-output control problem. Therefore we can specify the input-output characteristics of multiple-input/multiple-output systems. However, for non-minimum phase systems, no paper consider a design method for stable decoupling control systems using full state feedback control and dynamic precompensator. In this paper, we propose a design method for decoupling control method for non-minimum phase systems using full state feedback control and dynamic precompensator. In order to design stable decoupling controller, we use the fusion of the method by Falb and Wolovich and dynamic precompensation. A simple numerical example is shown to illustrate the effectiveness of the proposed method.

This paper describes a new control method for a redundant parallel manipulator using an internal force sensor. In conventional control methods of a redundant parallel manipulator, optimal torque minimized actuator torque or maximized manipulability by using evaluation function is decided and used. However, these methods have to use a torque controlled actuator. It's torque is small, also it is expensive. So, we propose a new control method using a conventional geared actuator in this paper. In our method, internal forces produced by actuator redundancy is detected by an internal force sensor and controlled to be zero. We demonstrate about the proposed control system and the structure, the principle, and the experimental result of the redundant parallel manipulator using the internal force sensor.

This paper presents a non-linear control for a magnetic levitation system of a flexible object based on passivity of the system. There are many researches on a passivity-based controller for the flexible manipulators. In these researches, controllers are designed without approximating flexible links into finite order model by truncating higher order vibration modes and linearizing non-linear terms in a neighborhood of an equilibrium point. Such linear finite controllers do not cause spillover phenomena and make wide operating area. In this paper, the magnetic levitation system is divided into two subsystems : an electrical subsystem and a mechanical subsystem. The controller for each subsystem is designed independently based on passivity. The dynamics of the flexible object are fully addressed and the results are valid for large deviations from equilibrium. The obtained controller dose not need current feedback for the electrical subsystem and consists of position, velocity and deflection rate feedback for the mechanical subsystem. It ensures asymptotic stability of the position trajectory and suppression of the elastic vibration. To illustrate the validly of our controller, some experimentals are carried out.

In this paper, we examine the anxiety at utilization of wheelchairs. When the human use wheelchairs, from the influence of environment, the human feel a sense of unease. In particular, when the human go up slopes using wheelchairs, the human feel a sense of unease. The sense of unease is under influence of the organ of vision and the vestibular organ. In this paper, we clarify the relation between the sense of unease and the vestibular organ, when the human go up slopes using wheelchairs.

The printing method of the thermal transfer printer is to push an ink ribbon that is heated and melted by a thermal print head to a printing paper, and transfer the ink desired positions on the paper. Thus it is important to place the heater of the thermal print head at the position where the contact pressure is most high. The visco elastic properties of the ink, PET and platen rubber were measured with a rheometer. The contact pressures on the thermal print head were calculated by FEM. The contact pressures under consideration of visco elasticity were different from those calculated by elastic analysis. The effect of sliding speed of the thermal print head on the contact pressures was also examined. To examine the effect of the contact pressure on the print quality the optical densities were measured with the heater positions of the thermal print head changed. The optical densities were changed with the heater positions. It can be found that the optical densities decreased with the calculated contact pressure.

In the present paper, we examine a design method for 2-degree-of-freedom repetitive control systems. The 2-degree-of^freedom control has good characteristics, such as the input-output characteristics for the reference input and feedback control characteristics can be independently settled. 2-degree-of-freedom controllers consist of the feedforward controller and the feedback controller. Design method of feedback controller for the repetitive control systems has been considered sufficiently, but design of feed-forward controllers for the repetitive control system has not been considered yet. In order to design feed-forward controller for the repetitive control system, we must solve the interpolation problem. In addition, the interpolation problem for feed-forward controller for the repetitive control system has many interpolation points. No method has been proposed to solve the interpolation problem for feed-forward controller for the repetitive control system. The purpose of this paper is to give a design method for feed-forward controllers and to propose a design method of 2-degree-of-freedom repetitive control systems.

In this paper, the solid tetrahedron element with drilling degrees of freedom is presented. This element has only four nodes. Each node has three translational components and three drilling ones. By using this element, the high level of analytical accuracy can be obtained. On the other hand, the free mesh method creates tetrahedron elements locally around every nodal point. Consequently, the element with intermediate nodes is not available to the free mesh method. However, the proposed solid tetrahedron element with drilling degrees of freedom is especially effective to the free mesh method, because it has no intermediate nodes. In this paper, the feature of accuracy of this element is shown through several numerical examples, and the effectiveness of the free mesh method is also described., 論文

This paper considers a design method for delayed-inverse systems for time-invariant strictly proper digital systems, which exactly reproduce the input with some delay. The inverse system must be stable in practical applications. It is well known that the inverse system is unstable if the system has invariant zeros outside the unit circle. The purpose of this paper is to give a state space design method for stable delayed-inverse systems such that the series-connected system, which includes the system and the stable delayed-inverse system, is a diagonal rational function. As a preliminary, we construct the delayed-inverse system by the usual method and factorize the delayed-inverse systems into several subsystems. The stable delayed-inverse system is obtained using observer design for subsystems of the delayed-inverse system. A simple numerical example is also shown.

This paper introduces elliptic Gabor wavelets with the triangular lattice configuration as a model-based target recognition approach. And, making the degree of overlap uniform between the neighboring Gabor wavelets in the frequency domain, it enables to cover the frequency space with higher density than the existing circular Gabor wavelets with square lattice configuration. Thus, it succeeds efficiently to extract a rotation and scale invariant features of the target objects. This paper, furthermore, presents some useful guidelines for designing system parameter values by a large amount of experiments, and shows effectiveness of the proposed method by comparing it with other methods.

The mutual interference of plural wind turbines becomes important when many wind turbines are located in large-scale wind farm. Several papers have analyzed the problems of mutual interference among plural wind turbines. However, the effects of boundary layer profile and turbulence in wind for mutual interference of plural horizontal axis wind turbines (HAWTs) are still unknown enough. In order to solve such problems, extensive experiments were performed in a large-scale wind tunnel. The paper describes the following points, (1) experimental analysis of wake behind HAWT for two different flow patterns, (2) relationships between HAWT performances and two different flow patterns, (3) detailed investigation for mutual interference between two HAWTs, through wind tunnel testing for two kinds of artificial flow patterns.

This paper deals with the case that an algorithm of continuous-time sliding mode control in which feedback gain coefficients are switched is digitally implemented in a digital computer. Since these coefficients are changed only at sampling instants, the system trajectory cannot be perfectly confined on a sliding hyperplane. As a results, the performance deterioration occurs. In this paper, the range is shown in which the switching control input guarantees to drive the state trajectory toward the sliding hyperplane and the swtching control algorithm is modified to be effective in it. A control algorithm is also proposed to keep the system trajectory in the narrowest neighborhood of the sliding hyperplane after the trajectory moving outside the range. The same discussion is further done for output tracking systems using sliding mode control. Finally, a numerical example is given for demonstrating the validity of the theoretical results.

In the present paper, we examine a design for repetitive control systems with multi-period repetitive compensator. The repetitive control system is a type of servomechanisms for periodic signal. The repetitive control system is a neutral type of time delay system and can not apply for strictly proper plants. Almost all plants are strictly proper. Several modifications of repetitive control system for strictly proper plants are proposed. One of them, it is well known that the modified repetitive control is easy to apply for strictly proper plants. Sugimoto and Washida point out that if time-delay is settled to cancel the phase angle of low-pass filter in the repetitive compensator, then the disturbance attenuation characteristics is improved. However, the method by Sugimoto and Washida improve the disturbance attenuation characteristics in only low frequency range. Generally, the disturbance includes variable frequency signals. In this paper, in order to attenuate the disturbance with higher frequency range, we overcome this problem and propose a design method for repetitive control systems with multi-period repetitive compensator. In addition, a design method for repetitive control systems, which is stable, is given.

In this paper, we examine a design method for robust control systems with robust stability for minimum phase systems using phase information. Yamada clarified that, using phase information, low sensitivity control systems with robust stability can be achieved if the relative degree of plant is equal to or 1-degree smaller than that of the nominal plant. In many cases, it is difficult to obtain the accurate relative degree of plant. The purpose of this paper is to expand the result by Yamada and give a design method for low sensitivity control system for the system with uncertain relative degree using phase information. In order to design low sensitivity control with robust stability, we adapt the idea of fusion of robust control design using phase information and the parallel compensation technique. A design procedure for low sensitivity control with robust stability is presented. Finally, without solving interpolation problem, a design method for low sensitivity robust servo control systems with robust stability is presented.

In previous papers, the authors proposed two types of passive dampers using a lever-typedisplacement magnifying mechanism. One is a magnetic damper using rare-earth magnets and theother is a viscoelastic-friction damper using acrylic viscoelastic material.In this paper, a new type of hybrid damper using a lever-type displacement magnifyingmechanism, giant magnetostrictive actuators and rare-earth magnets is proposed. The hybriddamper generates controllable friction force together with magnetic damping force which acts as afail-safe mechanism in case of control system trouble, and is suitable for vibration in the region ofamplitude 0.1 ~ 10 mm. The trial damper was made and the resisting force characteristics weremeasured. The seismic responses of a three-dimensional piping system supported by the damperwere measured using an electrohydraulic type shaking table. The experimental results are comparedwith the calculated results obtained by the finite element method (ANSYS), and the effects ofvibration suppression of the hybrid damper are discussed. Moreover, these experimental andcalculated results are compared with those obtained for a semiactive friction damper (which is oneremoved the rare-earth magnets from the hybrid damper) and a passive magnetic damper (which isone removed the giant magnetostrictive actuators from the hybrid damper).

In the present paper, we examine the Model Feedback Control System. Since the Model Feedback Control System is simple, the ModeI Feedback ControI System has been applied to many applications such as the trajectory control of robot manipulator, level control of serially connected tanks and so on. Since the control structure of the ModeI Feedback Control System has constrained, it is likely that the Model Feedback Control System can not represent all of stabilizing controllers for the plant. Nothing has been reported whether or not, the ModeI Feedback Control System can represent all of stabilizing controllers. The purpose of the present paper is to give a solution to the question whether or not, all of stabilizing controllers for the plant are written as the Model Feedback Control structure. Since Model Feedback Control System is applied to many minimum phase systems, in the present paper, we especially clarify the relationship between the ModeI Feedback Control System and the parametrization of all stabilizing controllers for the minimum phase system. First, the relationship between the Model Feedback Control system and the parametrization by Glaria and Goodwin is clarified. Next, for the strictly proper system, the relationship between the Model Feedback Control System and the parametrization by Yamada and Moki is presented. Simple design method of the Model Feedback ControI System to specify control characteristics is shown.

Demands of medical implants such as artificial hones increase as an aged society is coming. A medical implant can be substituted for original tissue only when it satisfies both mechanical properties and biocompatibility. Since such material is not found in nature, hybrid materials are promising and have been developed. In the previous paper, coatings of hydroxyapatite (HA) were deposited on titanium substrate by graded plasma spraying, but the properties of obtained coatings were inferior to those of bone. In this paper, two successive processes were conducted as a grounding of spraying. First stage is a formation of titanium compound which is processed chemically to titanium by NaOH and have high adhensive strength to both titanium and HA. Second stage is HA coatings self-deposited by dipping titanium in Ringer's solution. On these films, 50 μm thickness coating of HA was carried out by plasma spraying in vacuum chamber. It was clarified through the observation of self-deposited surface with SEM and AFM that increase of self-deposit time resulted in improvement of adhensive strength. Self-deposited surface becomes rough in microscopic order but keeps smoothness in mesoscopic, when self-deposited particles of HA grow and cover over the substrate surface. Such surface is easy to bond the sprayed particles by anchor effect as well as chemical affinity and results in increase in adhensive strength.

We suppose that most organisms have the optimized structures under various environment, but its mechanism has the most complex and many unknown factoTs. In this paper. we propose that it is useful in engineering to obtain the mechanism of a bamhoo structure using the laminate sheet model, through the experiments and the observation of the organizational structure within fibers of a bamboo. Based on the fundamental research of the fiber contents and strength of the bamboo's slices, we could learn how to construct the more fiber or the laminated composite structures by numerical analysis of the elastic-plastic FEM. This paper denoted that it is applicable to obtain the organizational properties of bamboo by the laminate sheet model., 日本機械学會論文集. A編, 69(677), pp.148-153; 2003

We suppose that most organisms have the optimized structures under various environment, but its mechanism has the most complex and many unknown factoTs. In this paper. we propose that it is useful in engineering to obtain the mechanism of a bamhoo structure using the laminate sheet model, through the experiments and the observation of the organizational structure within fibers of a bamboo. Based on the fundamental research of the fiber contents and strength of the bamboo's slices, we could learn how to construct the more fiber or the laminated composite structures by numerical analysis of the elastic-plastic FEM. This paper denoted that it is applicable to obtain the organizational properties of bamboo by the laminate sheet model.

This paper presents a non-linear control of a magnetic levitation system without current feedback based on passivity of a system. The magnetic levitation system is essentially non-linear. However, most researchers are modeled it as a linear system. If the object is far from the equilibrium point, a linear controller cannot compensate large gap between the magnetic coil and the object levitation. Some applications such as magnetic levitation conveyance system require large levitation gap control. In such cases, the linear controller sometimes makes the system unstable. In this paper, a non-linear controller based on passivity is introduced. The magnetic levitation system is decomposed into two subsystems, electrical subsystem and mechanical subsystem. The non-linear controller is designed for each subsystem. Controller for the electrical subsystem is designed by using kinematic-energy-shaping and PID controller is used for the mechanical subsystem. The asymptotic stability of the closed-loop system is proved by Lyapunov stability theory. The derived controller needs position and velocity feedback but not current feedback. Numerical simulation and experimental results show the validity of the proposed non-linear controller.

In the previous paper, the authors proposed a new type of magnetic damper using a lever-type displacement magnifying mechanism and rare-earth magnets. In this paper, a viscoelastic-friction damper and a viscoelastic damper using the lever-type displacement magnifying mechanism and viscoelastic material are proposed in order to obtain a passive damper which gives damping and stiffness within a relative displacement in the region of about 0.1~20 mm. Denoting the magnifying ratio by λ, the damping force and the spring force of the viscoelastic material are increased λ2 times and the friction force is increased λ times by the magnifying mechanism. The trial dampers were made and the resisting force characteristics were measured. To describe the mathematical properties of the viscoelastic material, a four-element viscoelastic model was used, and the parameters of the model were identified using the experimental results. The frequency responses and the seismic responses of a three-dimensional piping system supported by each damper were measured using an electrohydraulic type shaking table. The experimental results are compared with the calculated results obtained by the finite element method (ANSYS), and the effects of vibration suppression of the dampers are discussed.

In a previous paper, we developed a new method of measuring a distribution of real contact area between two solid surfaces using PET film. Tiny protuberances on the PET film were produced to reduce its friction. In the measurement, these protuberances could not be distinguished from the real contact area. Thus the calibration was needed to remove the effect of the protuberances before the experiments. In this paper, we produced four kinds of polymer films without the protuberances on their surfaces. The real contact area was measured with those polymer films. We discussed the effect of the mechanical properties of those polymer films on the measurement. It was found that the elongation property of the polymer was important to this kind of measuring method.

This paper presents a shape optimization method to displacement path control problem taking into account geometrical non-linerity. The aim in this paper is to minimize the time integration of squared displacement error norm on the responded mode and the prescribed mode by varying a boundary shape under a volume constraint. The shape sensitivity is derived using the Lagrange multiplier method and the formula of the material derivative. A procedure to solve this problem using the traction method is presented,which one of the authors has proposed as an approach to solving domain optimization problems.The validity of proposed method is verified by applying to basic numerical examples.

Piezoelectric ceramic is ferroelectric and is showing a significant hysteretic loop in its displacement response. This paper deals with the development of a linear compensation circuit for piezoelectric ceramic actuators by the self-sensing feedback control technique. In this paper, the concept of self-sensing feedback control technique and the circuit design were presented in detail, and the effect of the electric leakage in the piezoelectric actuator was investigated. A new idea for improvement of the effect of the electric leakage on the displacement drift in piezoactuator has been proposed simply by adding compensatory resistors in the circuit.

When a grasped object is in contact with external environment, it is required to identify contact conditions prior to performing assembly tasks. This paper discusses a method for identification of contact conditions by using an active force sensing method. This paper treats the practical case where sensing data are contaminated with noise. Contact types are characterized by a standard deviation of contact moments. The contact position is estimated by a least-squares method. The contact type can be judged by comparing the eigenvalues of a covariance matrix of estimated contact moment. We establish an efficient and analytical algorithm for identification of contact conditions. The algorithm can identify not only contact position and contact force, but also contact type.

This paper presents a numerical solution to boundary shape optimization problems taking into account material non-linearity. The goal aimed in this paper is to minimize external work by varying a boundary shape under a volume constraint. Shape variation is described by using a one-parameter family of mappings defined in a domain where a continuum lies initially.The shape sensitivity is derived using the Lagrange multiplier method and the formula of the material derivative.A procedure to solve this problem using the traction method is presented, which one of the authors has proposed as an approach to solving domain optimization problems.The varidity of proposed method is verified by applying basic numerical examples and by comparing with results considering only linearity.

In the first part of this paper, a series of systematic experiments of 5083 AI alloy are carried out at 833 K to elucidate the characteristic features of superplastic deformation under multiaxial loading conditions. Proportional deformation tests at constant strain-rates show that the initial yield stresses obey the Prager-Drucker criterion. It is also shown that under constant strain-rate tests the material hardens under tension, while it softens under compression. Significant strain-rate dependence of the flow stresses is elucidated for tension, compression and torsion loadings. In the second part of the paper, the constitutive model of superplasticity formulated in the previous paper is improved to obtain better description of the drop of the flow stress due to cavity growth under tension loading. For this purpose, the concept of effective stress and the strain equivalence principle of continuum damage mechanics are introduced into the model, and the relevant evolution equations are modified. Comparison of the results of the proposed model with those of the corresponding experiments shows that the proposed model gives better predictions than previously proposed by the authors.

Piston motion which interacts with lubrication characteristics including friction force between the piston and cylinder has been measured in order to prove the oil whirl phenomena in an axial piston pump and motor which had been found theoretically in the previous paper. The piston motion has been measured by means of eddy current displacement sensors, comparing with calculated results. It has been verified that the piston has whirled in the cylinder under certain operating conditions and specifications, similar to the oiI whirl phenomena as self-excited vibration in journal bearings. The phenomena have not occurred for wide clearance and short sealing part between the piston and the cylinder as the previous paper predicted them. The period of piston whirl has coincided with that of friction force variation.

This paper presents a method of micro-vibration control of milling machine heads by use of vibration absorber. The principle used in the paper is different from usual absorbers. In the present absorber, an auto-tuning vibration absorber is presented in which the absorber create anti-resonance state. When the anti-resonance is used, the damping has to be significantly small, so it is difficult to suppress higher modes. To suppress higher modes, the present article uses autotuning magnetic damper. It damps higher modes, but it also increase first modal vibration. Then a method of optimal auto tuning control is presented in which both principal and higher modal vibrations are suppressed. Experimental tests are carried out for a real milling machine, and cutting tests are also performed.

The present paper proposes a new design method in which a controller acquires the required performance automatically. Two important tasks of the control designer are the creation of a simulator of the plant dynamics and the determination of the evaluation of the controller. A three layered neural network of 4-inputs and 1-output controls the plant. The proposed method requires little knowledge of difficult control theories. Genetic algorithm (GA) evolves the neural networks to enable the control of nonlinear systems. The evaluation method originally proposed in this paper is very simple and easy to understand, so that it can be used even by non professionals working in the field of control. In order to demonstrate how to apply the proposed method, the present paper analyzes the load swing suppression of a crane system on a cart. Simulations reveal that the neurocontroller has higher performance than the linear quadratic regulator (LQR) with respect t settling time and robustness. The neuro-controller is able to suppress load swing even in environments that exceed design specifications., 論文

The paper, part 1, has proposed a mathematical model of rotor motion for piston rod driving type bent axis type axial piston pump in order to study lubrication characteristics between rotor and spherical valve plate. The numerical calculations have been carried out under operating conditions and specifications. The calculation results have been compared with experimental ones given by previous papers. It is found that (1) the rotor moves to delivery area and its axis tilts to one with its rotation, (2) film thickness between the rotor and the spherical valve plate minimizes at inside sealing part and the center of fluctuation locates near neutral point of the delivery area, and (3) the minimum film thickness and friction moment are greatly influenced by rotational speed, viscosity and dimension of sealing part on the spherical valve plate.

In a previous paper, a method for cutting hypoid pinion was proposed. In the method, instead of a basic member which is a hypothetical gear conjugate to ring gear, a newly introduced quasi basic member is used as the actual tool gear to generate the pinion. The quasi basic member is an approximate gear of the basic member. This paper introduces the method for setting up the quasi-basic member on the hypoid gear generator, namely, the method for calculating the machine settingS. The calculation starts with the designation of a central point of tooth bearing on the ring gear tooth surface. The pinion tooth surface which is generated by the quasi basic member becomes approximately a conjugate surface, so that the transmission error of this gear pair is very small. The proposed method does not need the so called tooth bearing development. When the experimentally made pinion was engaged with the ring gear given previously, the tooth bearing was desirable one.

This paper presents a practical method of numerical analysis for boundary shape design of steady-state heat conduction fields to control temperature distribution to a prescribed distribution.Reshaping was accomplished by the traction method that was proposed by one of the authors as a solution to domain optimization problems in which elliptic boundary value problems were defined.In this paper,we formulated a temperature square error norm minimization problem between prescribed distribution and actual distribution on prescribed boundaries and theoretically derived shape gradient function for this problem.We developed a convenient numerical method using a ganaral-purpose FEM program for the temperature prescribed problem.The successful results for two-dimensional problems of a erosion surface on blast furnace hearth and a coolant flow passage in turbin blade show the validity of the presented method.