An experimental identification technique for joint properties of structures and machines is considered. The technique uses transfer functions of the objects before they are assembled. The technique requires neither application of the excitation on nor measurement at the joints. The technique can identify the joints with nonlinearity. The main procedures of the technique are : (a) to model the joints by springs and dampers as well as equivalent masses and moments of inertia, (b) to apply the periodic excitation and to measure steady state responses of the objects in the assembled state, and (c) to determine the joints properties by use of the transfer functions and by applying the principle of harmonic balance. Numerical simulation is conducted, and applicability of the technique is confirmed.

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Analytical results are presented on chaotic vibrations of a shallow arch with initial configuration of catenary. The shallow arch is simply supported at both ends and is subjected to periodic lateral force. Equations of motion are reduced to ordinary differential equations of multiple-degree-of-freedom system by the Galerkin procedure. To clarify effects of sag-to-span ratio on chaotic motions, first, steady-state responses are calculated by the harmonic balance method. The chaotic responses are obtained by numerical integration and are examined by Poincaré projection, the maximum Lyapunov exponent and bifurcation diagrams. For the arch with comparatively small sag-to-span ratio, chaotic vibrations are generated mainly in the regions of subharmonic resonance of 1/3 order and of ultra-subharmonic resonance of 3/2 order, accompanied by the lowest-symmetric-mode of vibration. As the sag-to-span ratio increases, chaotic responses are generated from the subharmonic resonances both of 1/2 and 1/3 orders. Furthermore, chaotic motion appears within a wider range of exciting frequency and the number of modes that contribute to the chaos increases. Period doubling bifurcation was mainly observed in the bifurcation from periodic responses to chaotic ones. Hopf bifurcation was also found for the arch that satisfies the condition of internal resonance.

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This study analyzes the mechanism how a rider's vibration caracteristics affect the weave mode of two-wheeled vehicle using the Energy Flow Method, that calculates energy flow of external forces in each motion. Weave mode is stabilized when a rider's vibration characteristics are considered. The external force generated by a rider's upper body acceleration stabilizes rolling motion. Stabilization of rolling motion advances the phase of front tire side force via external force generated by rolling acceleration in the steering motion. This phase lead stabilizes lateral motion by external force generated by yaw rate. Finally weave mode is stabilized. Changing parameter concerning a ride's vibration characteristics affects weave mode stability, and we can also clarify its effect mechanism using the Energy Flow Method.

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Undesirable vibration and chatter are commonly recurring problems in process of thin plate rolling. The traditional approaches to control chatter were to improve lubrication conditions or to be equipped with chatter monitor as a warning system, for instance. But the both methods are not always effective. Then, this paper deals with new approach to control chatter vibration in 4-high tandem cold mill. The flow of approach methods are as follows ; (1) The theoretical model is constituted to simulate the vibration behaviors of the 5-stands continues cold rolling mill under various operating conditions. (2) Some approaches to control chatter are considered and the effect of each method was simulated using the theoretical model. (3) The effect of the tuned mass damper as the device to control chatter in the tandem cold mill was evaluated numerically. The results were good agreement with the experimental ones of the practical mill.

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The quantitative condition starting vibration of pipes by the flow across pipes in fluidized bed was studied experimentally. The occurence of self-excited vibration was observed over the critical flow velocity for a group of pipes, but on the other hand, no self-excited vibration observed for a single pipe. This vibration was found to be fluid elastic vibration. The resonance vibration of pipes caused by karman vortex was not found in fluidized bed even when Re is over 100. From the result of the experiment, the coefficient which determines a critical condition of fluid elastic vibration was found to be close to the value of liquid (water) instead of gas.

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A new analytical method to derive exact global form of all symmetric periodic solutions appearing in one degree of freedom forced zero stiffness impact oscillator is proposed. The author has been proposed a method to obtaining general solutions globally by linearize piecewise linear system to convert it's nonlinearity to virtual external force, and applying the principle of superposition for equivalent exact linearized system. According to this method, the function form of periodic solutions are represented by superposition of stationary periodic solution for linear system and finite number of periodic functions which are constructed by infinite number of responses caused by converted nonlinearity. However, since this infinite summation becomes a divergent series for zero-stiffness case, the value of this series is unknown. In order to overcome this difficulty, we formerly proposed a calculation method of these divergent series using Cesaro's summation, a kind of technique to extract physically reasonable finite value of divergent series. In this paper, we extend this formerly derived result to determine global form of all symmetric periodic solutions. The value of divergent series is calculated as (C.1). Cesaro's summation for viscous damped case, and (C.2) summation for undamped case, respectively. The validation of proposed method is confirmed by numerical example.

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This paper deals with a theoretical analysis and experimental study of combination resonance of the flexible bellows subjected to oscillating internal fluid pressure excitation. The governing equation of the bellows is expressed with the Mathieu's type equation. The parametric instability boundaries of bellows are calcuated by the first-order approximation analysis using perturbation method. As a result, it is clarified that combination resonance occurs in the bellows due to the oscillating internal fluid pressure excitation. And the theoretical results of the parametric instability boundaries agree well with the experimental results.

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In the previous report, a new hydraulic draft gear, which had a function of controlling the coupler force, was discussed. The device introduced in the report aimed at lowering the coupler force acting between the failed and the relief Shinkansen train set. The results of excitation test on a prototype device based on analytically obtained specifications showed poor tracking performance of the hydraulic cylinder during return stroke while an increase in residual deviation when increasing the operation speed. In this paper, a hydraulic buffer resolving these problems is developed. The results of an excitation test that confirms its performance are described. The device, which arranges a hydraulic cylinder in the form of no rubber pad, adopts a piston return mechanism with pre-pressurization in the hydraulic circuit to improve the tracking performance. The coupler force is controlled by a PID controller to lower the deviation and improve the performance. An optimization methodology based on a non-linear model is proposed for the design of controller. The methodology is verified experimentally with a prototype performance.

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Recently a new type of impact damper, whose impacting body is made of elastic material, has been developed. This type of impact damper is called elastic impact damper. In a previous report, the authors studied the effect of the elastic impact damper, and clarified its damping mechanism. In that report, a single-degree-of-freedom system is taken up as the object of vibration suppression. In this report, a continuous system is taken up. As an example, a beam is considered. Possibility of vibration suppression of resonances for several modes of the beam is studied by numerical simulation and experiment.

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To reduce wind-induced vibration of tall buildings and bridge towers, tuned mass dampers are often used. These dampers are called “passive type” while the methods which reduce the vibration by controlling the motion of a large mass with an actuator are called “active type”. For these types we have to change or control the structural vibration characteristics themselves, therefore they need very large exciting forces, and the system will become very large for large structures. In this view point, new concepts have just begun to be studied, where the driving forces themselves will be controlled. In this paper, we proposed a new system for reducing the flow-induced vibration of the structures by utilizing fluid excitation force itself. In this system, as we control the direction of the driving forces, this system does not need so large control forces and the system becomes smaller and simpler. We investigated the feasibility of this system when applied to a bridge, a building and evaluated the effectiveness of driving forces by the wind test using a reduced scale model.

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Body panels in automobiles are usually stiffened by beads and are covered with viscoelastic damping layers. In the first report, method of numerical analysis for modal loss factors of the bead panels were verified by experimental results. In the analysis, asymptotic method was applied to complex eigenvalue problem using three-dimensional FEM in consideration with complex material parameter. In the second report, influences of geometry (height, length, interval) of the beads on modal loss factors were clarified. In this report, layouting the viscoelastic materials on the surface of the bead panels using damping contributions of positions of the materials to modal loss factor properly, modal loss factors can be improved. Further, by investigating bead shapes which can concentrate distribution of dissipated energy on local area in the panels, effective shape of beads is proposed in consideration with modal loss factor, light weight and rigidity.

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Vibration isolator of rubber pads has a hysteretic nonlinearity. Function of the vibration isolator has been raised by combining hydraulic device with rubber pads for introducing damping effect and by attaching a stopper to the rubber pads for limiting amplitude. Preisach distribution function, which makes it possible to evaluate equivalent damping coefficient and stiffness in terms of excitation amplitudes and frequencies in equation of motion, was proposed to describe hysteretic nonlinearity, whichever it may be analytically or experimentally provided. In this paper a new simpler method for deriving the distribution function than the previous one, which urtilizes matrix, is proposed. Frequency response characteristics of single-degree-of-freedom with a hydraulic rubber pads was evaluated in terms of equivalent damping coefficient and stiffness, and the comparison with those by time historical analysis and by excitation experiment demonstrates good agreement. Consequently this shows a firm and general design procedure for the mechanical system with such nonlinear element.

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The radiation efficiency of a plate excited with a large number of modes has been examined. Modal approach has been conducted for an acoustic cavity which has a flexible portion (plate) of the wall surface. The simple expression for the radiation efficiency of the plate has been derived under the condition that the coupling between plate and cavity is weak. Though the expression includes the terms of the interaction between structural modes of the plate and acoustic modes of the cavity, it is simpler rather than full-coupled expression. Numerical experiment has been carried out for a rectangular enclosure with a surface vibrating as a simply supported plate. Simulation results show the classical Maidanik equation has somewhat errors in case of radiation to a cavity at frequency range below coincidence. The radiation efficiency fluctuates largely when the number of modes is small and the loss factors of a plate and an enclosure are extremely small. In those cases, the expression derived in this paper is useful to calculate the radiation efficiency of a plate.

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The goal of this research is to analyze vibration response when the main mirror in a Satellite Solar-B optical telescope assembly (OTA) is subjected to an acoustic load. Specifically, in this second report, we focused on high frequency band vibration in which the satellite's local vibration mode is the main vibration. First, we studied methods of analyzing the response of the OTA structure and calculated the response using a Statistical Energy Analysis (SEA) method. Next, we measured the response multiple from the OTA structure to the main mirror and multiplied this by the previous response analysis results of the OTA structure to calculate the response of the main mirror. Regarding response RMS, the calculation results and the acoustic test results matched with an error of less than 3 dB. During these studies, we also confirmed significant vibration attenuation effects in such structures as the shield tubes that we designed.

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This paper deals with an approximate numerical simulation method of the three dimensional acoustic problems. Cores of this method consist in analytic solutions expressed in the 3D polar coordinates and the collocation method. Boundary conditions are satisfied approximately only at points placed on boundaries of domains. As numerical examples, free vibrations in a domain of frustum of pyramid are calculated. The domain is bordered with rigid walls. Calculated natural frequencies and calculated natural modes expressed by sound pressure distribution on a cross section agree well with experimental results. Furthermore, forced vibrations in a domain bordered with a sound absorbing wall and rigid walls are examined. Measured values of specific acoustic impedance of normal incident of sound absorbing material is used. Calculated results of sound pressure distribution on a cross section also agree with measured ones. It can be concluded that the proposed simulation method is reliable.

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Accurate seismic analysis of large deformable moving structures is still unsolved problems in the field of earthquake engineering. In order to analyze these problems, the nonlinear finite element method formulated by the absolute nodal coordinate approach is noticed. Because, this formulation has several advantages on mass matrix, elastic forces and damping forces in the case of large displacement problems. But, it has not been fully studied to build a frame structure model by using the beam element in the absolute nodal coordinate formulation. In this paper, we propose the connecting method of the beam element formulated by the absolute nodal coordinate. The coordinate transformation matrix of this element is introduced into the frame structure. This beam element has the characteristic that the mass matrix and bending stiffness matrix are constant even if in the case of large displacement problems, and this characteristic is being kept after the transformation. In order to verify the proposed method, we show the numerical simulation results of frame structures for a static problem and a vibration problem.

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A formula of multibody finite element analysis based on the corotational formulated finite element method and the direct coordinate partitioning for deployable truss structures is proposed. A beam element used in linear finite element analyses is a basic element in the formula. A corotational frame is defined by node coordinate systems attached to a beam element. A tangent stiffness matrix contains a virtual rotation displacement of the corotational frame. By the appropriate transformation of this virtual displacement, a simple geometric stiffness for the formula is obtained. The formula makes it possible to analyze the deploying motions of large deformed deployable truss structures, to be applicable to general finite elements, and to increase convergence speed of the Newton method in a solution algorithm. This improvement is achieved by neglecting virtual work done by rigid body motion in the process of employing the geometric stiffness to the conventional formula. A validity of this formula is confirmed through results of a numerical deployment analysis of a deployable beam structure.

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Sliding-mode control has been introduced in many control fields because of its excellent robustness. Among various types of design methods of the hyper-plane, the optimal sliding-mode control using the feedback co-efficient of the optimal regulator is often adopted, because of the simplicity of design and the necessity for the optimal preview sliding-mode control. This paper describes asymptotic properties of the poles of the optimal sliding-mode control system. As the results, we found the following properties; (1) The asymptotic property of the poles of the optimal sliding-mode control system in γ→0 (γ designates a weight on control variable in the performance index.) inherits that of the optimal regulator and (2) In discrete time control, although the control system becomes unstable in γ→∞ for unstable plant, it becomes stable when we take γ smaller or use the design method which assigns the poles of the optimal regulator in a specified region.

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This paper considers the design method of discrete equivalents of analog controllers. Firstly, existing methods are reviewed with numerical examples and it is shown that they introduce extra phase-lags at high frequencies compared to the original controller. Secondly, a new design method for discrete equivalents of analog controllers is proposed. The proposed design method is an improved pre-warped bilinear transformation and is simple. The resulting digital controller does not have any extra phase-lag compared with the original analog controller in a frequency range under the maximum absolute value of poles and zeros of the analog controller, even when it is lower but comparable with the Nyquist frequency. Validity of the proposed method is shown by numerical examples.

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A preliminary investigation was conducted on electrostatic formation of a liquid drop. High voltage was applied between an insulative capillary tube filled with water and a metal plate electrode. Formation of a water drop was observed at the dark discharge under conditions of appropriate voltage application and water level. Although the electrostatic attractive Coulomb force is small, in the order of 10 μN at the voltage lower than the corona onset, it is large enough to separate the water drop to the capillary tube against surface tension at certain conditions. The diameter of the drop was about one millimeter. At the beginning of corona discharge, however, water mist was dispersed at wide angle from the tip of the tube due to the Coulomb repulsive force of charged mist. When the applied voltage was further icreased, water mist became to be dispersed like spray, because the ionic wind prevented the separation and spread of the droplet. Application of adjusted pulse voltage can form a droplet of which formation is synchronized with the pulse. The diameter of the droplet depended on the applied voltage and the tube diameter. The droplet volume was in the order of several hundred picoliters. Preliminary inkjet printing on a paper was also demonstrated. This phenomenon is expected to be utilized for a new inkjet print head.

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In a magnetic disk drive, a molecularly thin film is currently used as a lubricant and controlling its kinetic behaviors is a key technology to design the head disk interface. Direct visualization of molecularly thin lubricant films is useful in investigating the kinetic properties. To meet this demand, we demonstrated that the real time visualization is possible by using the ellipsometric microscope with a laser light source. However, the SNR of the image was limited by noises due to the optical interference and the improvement of the SNR was needed for a thickness resolution of sub-nm. In this paper, we demonstrate that the noises due to the optical interference can be reduced by using a white light source with lower coherence. The achieved SNR for a PFPE film image is about 61.4 in the white light source-based ellipsometric microscope whereas the SNR was about 9.4 in the laser-based one. This result indicates that the white light source based ellipsometric microscope can provide the real time visualization with a sub-nm thickness resolution.

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Electro-hydraulic servo system has been used in many industrial applications for high power in size, high response and fine repeatability. But, load variation causes a degradation of control characteristic. In this papaer, we introduce a scheduling parameter which is a function of hydraulic force against a load. Then, apply it for a controller design in order to maintain a steady control performance under the comparatively large load variation. There are many factors, which cause a time-delay between an input and an output, in the hydraulic system. It often produces unexpected over or undershoot when design an aggressive controller for high bandwidth feature to the plant. In order to have a desirable following behavior in the closed loop system, take a time-delay into consideration as a modeling error and attempt a trade off of rise-time and overshoot characteristic. The usefulness of this design approach is confirmed by the experiment.

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If the driving matrix B is positive definite matrix in n-input n-output systems such as x (t) =Ax (t) +Bu (t), x (t) ∈Rⁿ, it is very easy to design robust controller for the systems. In this paper we propose a robust lane keeping controller developed by using the fact above. First of all, a method to design a virtual ideal system is shown. Next, a robust controller is developed so that lateral velocity and yaw angular velocity of vehicle track the lateral velocity and yaw angular velocity of the virtual ideal system. The proposed controller has the good feature that lane keeping performance doesn't change even if vehicle mass, vehicle moment of inertia, etc. are varied. Finally, numerical simulation results are shown to specify effectiveness of the proposed controller.

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Power-assist system technology and its application to manufacturing systems have attracted special interest recently. For example, automobile assembly processes utilizing power-assist systems exist. Many power-assist systems for industrial uses possess simple power-assisting function only. Transfer of controlled objects is generally processed by another system. This fundamental study proposes a transfer control method of a cart with motor by means of a switching from the impedance control realizing the power-assist to the servo control for automatic transfer. To obtain smooth switching, this study utilizes a nonstationary impedance control method whose impedance parameters are time-varying. LQI (Linear Quadratic Integral) control method based on time-varying feedback gains is also introduced. By the consideration on setting of the time-varying parameters, control characteristic is smoothly varied without control input saturation. This method increases efficiency of control processes and realizes comfortable work for operators.

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Numerical solution algorithm for the optimal guidance law of AUV (Autonomous Underwater Vehicle) is presented when it transfers between two pre-designated points in the region of flow disturbances. In the formulation of optimal guidance problem, position vector of the vehicle relative to the inertial frame is qualified as the state vector, while the vehicle's heading as the input. Total amount of time to reach the terminal point is the performance index to be minimized. By solving the optimal guidance law, optimized sequence of vehicle's heading is obtained in time domain, which is to be fed to the heading control system as the reference. Proposed algorithm is applicable to the time-varying flow disturbances as well as time-invariant ones, if only the distribution of them is known a priori. Strategy of optimal guidance with tracking control is applied to the navigation of r2D4, a newly developed AUV by IIS, the university of Tokyo. Effectiveness of optimal guidance law shows its primary dependency on the local distribution of flow disturbances.

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There exist many applications of repetitive control on the factory floor, such as industrial robots and machine tool systems. Since most of the existing repetitive control systems are based on the so-called internal model principle, the system needs to include the internal model of the repetitive reference signals, which is usually higher order model. So it is difficult to apply the adaptive pole placement control because the controller needs to be higher order and a large number of controller parameters need to be estimated online. In this paper we propose a design of adaptive repetitive control systems that are capable of arbitrary pole placement. The proposed controller is based on the two degrees of freedom controller with repetitive feed-forward and adaptive feedback controllers. The adaptive feedback controller is also able to reject unknown disturbances by estimating the internal model of the disturbances. The method is applied to a SCARA-type robot and its effectiveness is experimentally examined.

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This paper considers decoupling control of a model helicopter with three degree-of-freedom. Since its position control system is not decouplable via static-state feedback, we try to apply dynamic-state feedback. In most practical cases, however, the model parameter cannot be measured accurately due to a difficulty of system parameter identification. Here, the online parameter estimation technique is introduced in the derived control loops. In this paper, a decoupling control method with the online parameter estimation technique is proposed under the presence of the parameter uncertainties and applied to an experimental system. The experimental results show the effectiveness of the proposed algorithm.

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Parallel loop simulation method (PLS) has two special features ; one is parallel loop construction including system models with each loops, and the other is using measured data of system behavior as input data. In this paper, stability and accuracy of PLS for general control system are analyzed using system theory and accuracy of low order system is analyzed quantitatively. Results show that, PLS realizes accurate simulation results of control system, by using not accurate system parameters.

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Isolation and separation of the target microbe is quite important. We propose a novel touch sensor for separation of the target microbe on the plate using a micromanipulator with the glass pipette. Principle of this touch sensor is based on detection of mechanical impedance change after contact of the vibrating pipette tip with the plate. We improved the fixation method of the sensor with the pipette as well as electrode design of the sensor.We performed the FEM analysis to improve sensitivity of this sensor. The prototype sensor has high sensitivity and high rigidity and is excellent in durability. This sensor is sensitive enough to protect the fragile pipette tip from abrupt collision. Thus, separation task of the microbe by the micromanipulator under the microscope is improved.

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In this paper, we propose a presentation system of virtual 3D shape information for visually handicapped persons. For displaying a virtual 3D shape, an industrial robot arm is used. A user of the proposed system touches a small plate that is attached to a tip of the robot arm by one hand and drives the arm by moving another hand freely on a guide plane. As the hand moves on the guide plane, the plate successively displays a tangential plane of a 3D shape that is stored in the PC beforehand. Since users can move the hand freely, they can perceive virtual objects with their own will. The experiment was conducted for 22 normal subjects and one visually handicapped with 4 kinds of simple 3D shapes. After the subject touches the virtual shape, it touches a real object and judges whether the two shapes are same or not. The experimental results show that the proposed system is useful for the vision substitute system.

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When wheeled mobile robots run fast on the rough surface, the devices loaded on the body are affected by the body acceleration and may be destroyed. In this paper, we propose a method to reduce the body acceleration of wheeled mobile robots. In this mobile robot, a ball screw is adopted as a mechanism to drive wheels up and down. To achieve small body acceleration, an ideal model is designed based on the state space description containing body acceleration. The information from accelerometers mounted on each wheel axis is used in the ideal model. Next, a robust model tracking controller is proposed. It is shown by carrying out experiments that the control performance is maintained even if the body weight is changed.

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A number of researches for the dextrous manipulation have been studied in robotics and physiologic fields independently. Multi-fingered manipulation for dextrous robot hands should be based on the analysis of human skills. The purpose of this study is to apply the CPG-based control to the dextrous manipulation. In this paper, CPG-based manipulation is proposed for the rotating manipulation. Manipulation patterns of fingers are investigated when a subject rotates a cylindrical object. Typical contact patterns during the rotating manipulation are measured by FSRs. Based on the observation, the neural circuit model which generates a similar contact pattern is constructed. The experimental results by the computer simulation suggest that rotating manipulation can be performed using the constructed CPG model.

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Force and torque induced by traveling motion and moving operations of a mobile robot effect, dynamically to the objects being carried on it. If the induced force and torque should be bigger than the maximum static friction force and torque, the carrying objects may start to slip on the mobile robot. Since this slipping motion may increase the acceleration of the mobile robot, then the slipping of one object may cause a collapse of all carrying objects, which is thought to be dangerous. Furthermore it interferes with accurate moving operations. A purpose of this research is to make a model of mobile robot which is carrying objects, to analyze the influences of the slipping to the traveling motion and to discuss a constraint conditions for the controller of guidance and moving operations to avoid slipping. In this paper, we propose a model of mobile robot including the slipping motion of the plural carrying objects. Using the proposed model, the influences of the slipping are analyzed and justification of the model is verified by simulations and experiments.

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This paper describes an evolutionary approach to design a mobile robot behavior using multi-objective genetic programming. Genetic programming (GP) has a tendency to create programs with unnecessarily large size. This problem in GP is called bloat and increases computational efforts. We introduce a multi-objective optimization technique to GP as a mean of controlling bloat, where a program size is treated as an independent objective besides another objective (fitness) and the modified domiance relation is used in evolutionary Pareto optimization. The proposed multi-objective GP can not only reduce bloat, but also avoid the problem of over-learning often found when applying GP to a behavior design of robots. The effectiveness of the proposed GP is demonstrated through the simulation and the real-world experiment using Khepera robot.

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The authors introduced the mental model and the Robot Personality for humanoids. The Mental Vector which expressed the mental state was defined in a 3D mental space and determined based on the Equations of Emotion. The Robot Personality consists of the Sensing Personality and Expression Personality. We implemented them to the human-like head robot WE-3RV. It could express the various mental states caused by stimuli from the environment.

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The purpose of the study is to evaluate quantitatively how the feeding robot we have developed could successfully assist eating behavior of the disabled who need assist for their eating. The robot has designed particularly to have the smooth coordinative movements between dishes and robot arms, by elaborating motion of the manipulator of robot's arms, which enable the disabled to eat all the contents of the plates without any left, as fast as the non-disabled, without spiting the food, with assist of the robot's arm. Thus, the study proved that this feeding robot could assist the disabled to eat as good as the non-disabled in time, in quantities, and in manner.

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Two driving mechanisms were constructed and these characteristics were investigated. The mechanisms utilize force generated in a pin-to-plate gas discharge system that consisted of a rigid pin electrode and a plate electrode. One of the driving mechanisms utilizes force generated at dark discharge region, because attractive force, in the order of 10μN, was induced to the pin electrode due to the Coulomb force at this region. A stator consisted of parallel plate electrodes on a plastic plate and small linear movers were needle and/or plate electrodes on floating plastic plates. Experimental investigation deduced that (1) the speed of the movers was increased at high frequency of the applied voltage and a small air gap, but (2) the motion of the movers were out of tuning over a threshold frequency. Another driving mechanism utilizes force generated at corona discharge, because corona discharge took place over a certain threshold voltage and a relatively large repulsive force, in the order of 100μN, was induced to the pin electrode due to the ionic wind. The force was almost tangential to the pin electrode even when the pin electrode inclined to the plate electrode. This force was utilized for driving small linear and rotational movers on water. The linear mover was an inclined pin electrode on a floating plate and the rotational mover consisted of two inclined pin electrodes on a floating disk at point-symmetrical positions. Experimental investigation deduced that (1) the driving force was induced over the corona onset voltage, (2) the driving force or torque were maximum when the inclination angle was 45 degrees, and (3) the speed of the movers was increased at high applied voltage and a small air gap.

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One of the most crucial issues in drilling is the detection and prediction of drill breakage in small diameter of less than 2.0 mm. When the drilling is irregular, due to factors such as a worn cutting edge or a hard spot in the workpiece, the drill deflects as a column and induces vibration as it scraps on the side or bottom of the hole, thus resulting in drill failure. If the drill edge position can be observed and controlled in real time, the drill breakage will be prevented and the machining accuracy can be improved accordingly. In this paper, a new mathematical drilling model is proposed in the form of transfer functions and then modified into a state space expression. Controllability and observability are investigated by the rank of their matrices obtained from state and output equations. It was found from analysis that the drill edge position is both controllable and observable.

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The studies of man-machine interface and human dynamics have been researched in many technical fields. This paper presents the way of building human models with considering voluntary muscle contraction. Firstly, methods for evaluating muscular activity properties during static and dynamic conditions were proposed. Secondly, human upper extremity model with muscular system was built and simulatied by using multi body dynamics analysis software, MADYMO. The muscular systems are based on Hill's characteristic equation. They generate the motion of the upper extremity with muscular contraction considering active state of muscles. Lastly, the validity of the model and the way of approach were confirmed.

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There are various factors that are concerned with the over-dependence on driving assistance system. In this study, we focused on the interference level of driver behavior and system operation, and also focused on the unpleasantness level during system operation, for designing Forward Collision Avoidance Assistance System. It was proven that all subjects initiated the braking operation in advance of system actuation (i.e., no interference was observed) to minimize the risk of collision and dependence level on the system was extremely small, when the target stopping point was set at the backward of the obstacle and the deceleration level was set at 6.0 m/s² and more. It was also proven that all subjects canceled the system operation to minimize the unpleasantness and the dependence level on the system was extremely small, when the deceleration level is 6.0 m/s² and more.

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Transparent-Resinous-Ultraviolet-Curing-Type Braille (TRUCT Braille) signs printed over printed characters do not disturb sighted readers, thus these signs have spread rapidly. However, it is pointed out that sight disabled readers are hard to read TRUCT Braille because patterns of dots that consist of Braille (such as dot-height and distance-between-dots) are different from each printing marker. In this study, for the purpose of defining the readability of TRUCT Braille, we product the various patterns of TRUCT Braille and examine the influence of the dot-height and the distance-between-dots. The participants are beginners of Braille reading with normal vision to exclude the experience of reading Braille. They are given subjects to discriminate 6 letters (one of six dots is freely missing) consisted of various patterns of TRUCT Braille. From this study, we suggest the basical patterns of TRUCT Braille that are easy to discriminate.

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As for this research, the driver's risk at the time of cornering was evaluated. As a result, the amount of perspiration became a big difference though the change in the amount of the vehicle state of non-drive skill person and the drive skill person did not have a remarkable difference at the time of the drift cornering. That is, the amount of perspiration when the steer is controlled in case of the drive skill person is small. Therefore, it has been understood that it is a steer control of the risk which is not too large.

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Mutual dependence among machines in a decentralized manufacturing system is analyzed systematically in order to expand the applicability of recursive propagation method for scheduling, which is an information exchange procedure proposed by the author for management of machines. The dependence among machines is characterized by both the processes planning to manufacture a product and the operations associated with each process. In this paper, the types of the process and the operation are described in detail, and an improved recursive propagation method, which can cope with cooperative operations among plural machines, is proposed to make feasible schedules in complex manufacturing systems.

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In this paper, G-IREC is proposed. G-IREC is an extended IREC, which pays special attention to global design features which are in the form of curved shapes. IREC (Interactive Reduct Evolutional Computation) is a method to evolve designs based on users' personal preferences. The method works through an interaction between the user and a computer system. The computer system with IREC generates design samples consisting of random attributes and the user evaluates and scores each samples depending on his/her psychological preferences. The system estimates the design attributes that the user pays more attention to (favored features) with Reduct in Rough Sets Theory and reflects it to generate new design samples. This interaction continues until the samples converge to a satisfactory design. So far design parameters such as coordinate of nodes for spline curve have been regarded as design attributes. However, design attributes consist of not only detailed local parameters but also global features such as convexity, softness etc. In earlier design process, designers first drew a rough sketch to determine the outline of a design, and designed the details later. Therefore it is important to introduce global features to accelerate the convergence and to increase user friendliness. We develop G-IREC (Global feature based IREC) which allows to introduce global features in IREC. G-IREC (Global feature based IREC), which introduces global features into IREC, is applied to an automobile side board shape design. The effectiveness of this method is demonstrated by comparing the computed results with the experimental ones.

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The novel mechanism CVT (Shaft Drive CVT) was developed by the authors. The input and output shafts with conical disks are parallel and an idler shaft having conical rollers at both ends is placed perpendicular to the input/output shafts. This idler shaft transmits torque from the input shaft to the output shaft and its linear motion produces the speed variation by changing the contact point between the input/output disk and the idler roller. The purpose of this report is to design a curved shape of disk to decrease an amount of spin caused by the changing of contact point, because the spin has an adverse effect on traction contact performance and is responsible for an increase of power loss. The design procedure of novel concave disk and roller is shown and their effect is evaluated by using the prototype CVT. The speed -transmitted efficiency of 1.5% was improved in case of transmitted power 0.7 kW.

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Bearing surfaces of bolted joints have a heavy role to ensure tightening performance. The pressure distribution on the bearing surfaces is considered to be an important subject relating directly to that role. In this study, concerning the bearing surfaces of M 10 hexagon head bolts and M10 hexagon head bolt with flange, detailed analyses are done by a finite element method to consider the pressure distribution. The main purpose of the analyses is to solve influences by inclination angle φ_p and concavity angle φ_c which are regarded as the basic quantities of the angular deviation of the bearing surface. The pressure distribution is highly sensitive to both angles.It is known that even 1°of φ_p gives too much bias to the distribution and in hexagon head bolt with flange φ_c selected properly has an effect to adjust its shape (e.g.an adjustment to make the distribution more uniform). Additionally, practlcal suggestions are presented about the bending moment caused by φ_p and the equlvalent diameter of frictional torque influenced by φ_c.

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The rolling contact fatigue of a sprayed alumina ceramics with a nominal composition of Al₂O₃-2.3 mass%TiO₂ was studied with a two-roller test apparatus under pure rolling contact condition with oil lubricant. The alumina ceramics was prepared by plasma spray process. The influence of undercoating of sprayed Ni based alloy and surface sealing on the rolling contact fatigue was investigated. The failure mode of all sprayed rollers was spalling caused by subsurface cracking. Neither undercoating nor surface sealing contributed to the improvement of the rolling contact fatigue. The elastic modulus of the alumina sprayed layer evaluated with the nano-indentation method was around 85 GPa. The subsurface shear stresses were calculated with two-dimensional FEM analyses. The maximum values of orthogonal shear stress and maximum shear stress occurred within the sprayed layer. The depths of observed subsurface cracks were generally deeper than those of the maxima of shear stresses.

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The friction loss and noise of gears has been studied for along time, but it has not yet been made clear. Moreover, JIS gear accuracy class is not necessarily linked with the performance operation of gears, and hence it is important to find the relations between the tooth form accuracy and performance of gears. In the present study, we carried out the experiments to obtain the influence of tooth profile error on the friction loss and noise of spur gears. Nine kinds of tooth profile error with grinding with the similar error amount were used and also we prepared a barrel polished gear which had tip relief by grind. Test results showed that tooth profile error shapes affect the friction loss and noise very much even if the amount of error is the same. Further, it was found that the friction loss and noise have a certain correlation with each other and a barrel polishing showed the lowest friction loss and noise.

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This paper investigates the influences of various high-speed steel hob substrates coated with (Al, Ti) N film, which are no coating on the rake face by grinding, on a behavior of crater wear mainly, flank wear and finished surface roughness in dry hobbing. Experiments were carried out using fly tools, which were made of normal high speed steels (HSS) and powdered metal high-speed steels (PM HSS). As a consequence, an interesting result was obtained that the crater wear with the M 34 HSS tool is smaller than that with the all PM HSS tools tested at a cutting speed of 117 m/min. At a high cutting speed of 159 m/min, though a failure took place at a tip of cutting edge in some HSS and PM IISS tools, a SK II 51 and a corresponding to SKH 55 HSS tools have no failure, and they are effective for the crater wear. The corresponding to SKH 55 tool, M 34 tool and the PM-HSS tools containing high vanadium and high cobalt are suitable in terms of the flank wear and the surface finished, irrespective of the change in the cutting speed.

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