An electric active stabilizer suspension system has been developed as a technology for controlling vehicle roll. The system includes various sensors that detect the vehicle's running state, and active stabilizer actuators that use electric motors and reduction gears to control roll. The electric stabilizer suspension system was compared with hydraulic stabilizer systems, and an investigation demonstrated the superiority of the developed system, which offers outstanding vehicle behavior, improved responsiveness and reduced energy consumption (including energy regeneration).

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The research is to create a 3D design system which changes the development process in order to achieve early requirements determination. The studies have shown that the 3D CAD could have made development system more efficiently. The fact, many defects are caused in post-processes. The reason is that whether the design satisfies the requirements or not is considered by direct relation process. We extracted the manufacturing requirements and cleared the requirements of their dependency. Then, we defined structure of the data in 3D CAD system by considering all of the product development process. The system has 3 characteristics. It contains the mold solid data and manufacturing requirements (1). It makes design elements available only when needed to designers (2). The dependencies among design values are stored separately from 3D model (3). It is possible to reduce the defects and shorten the lead time by using it.

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A nonlinear theory is presented to describe oscillations of two liquid layers formed in a tank. By employing the variational principle, basic equations are derived, which goven interactions of two interfaces, the interface of two liquids and the free surface. The nonlinear ordinary differential equations for two dimensional flows in rectangular tanks are derived by applying Galerkin's method to the basic equations, which represent the nonlinear coupling between linear modes. Wave heights predicted by the analysis are compared with experimental results in previous works. There is reasonable agreement between the analyses and the experiments over the range of low-order mode resonance frequencies. Both the experiment and the analysis show the phenomenon that the interface of two liquids oscillates with the frequency of 1/6-1/7 of the excitation frequency at a particular excitation frequency region. The mechanism of this phenomenon is revealed by observing the time series of nonlinear forces which act on relevant modes.

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The theoretical and experimental study is carried out to investigate the dynamic characteristics of the liquid annular seals with a square-hole pattern in seal stator. The mometum equations with turbulent coefficients and the continuity equation, which are averaged across the film thickness, are numerically solved in consideration of the pressure jumps at each step between the land and the square-hole regions. This pressure discontinuity is evaluated based on the continuity of volume flow rate across each step and the generalized Bernoulli equation. The numerical results of the dynamic fluid force and the dynamic coefficients agree well with the experimental results, which prove the validity of the numerical analysis. The effects of the inlet swirl velocity on the dynamic coefficients and the whirl-frequency ratio are also described for the square-hole pattern seal as well as the annular plain seal with smooth surface and the parallel-grooved seal.

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Pitching machine is widely used in venues ranging from professional baseball stadiums to batting centers. However, the throw performance of the pitching machines that have been developed so far for use during batting practice is not very high. Pitches such as the fastball, curveball and screwball are easily achieved by the pitching machine with three rollers which were developed by the authors. In this study, the moving behavior and contact stress state of the ball pitched with the three rollers type pitching machine is analyzed using dynamic finite element analysis software (ANSYS/LS-DYNA). The effect of the seam of a baseball to the throw accuracy is analyzed numerically. In the analysis, the finite element models of a detailed baseball with a seam and a pitching machine with three rollers are used. Additionally, convex and concave rollers are made and those are analyzed. From the analytical results, it is understood that the convex roller is higher than other rollers in throw accuracy. The convex roller geometry is optimized, and the optimum conditions (shapes and material properties) of the convex roller are decided. Moreover, the validity of the condition is confirmed by the throw experiment.

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The numerical evaluation of impact characteristics of a cue in billiards is performed for the case where the ball trajectory is curved by hitting a ball on its upper left or right part with an inclined cue. The effective numerical method developed in the previous papers, in which a cue and a ball are assumed to be isotropically elastic and rigid, respectively, is extended for this case. The extended method is verified with an experiment using a high speed camera. The result obtained with the extended method also shows that the curvature of the ball trajectory is large for the impact on its almost exactly left part with a slightly inclined cue, and this result agrees with an empirical one. It is found from a numerical simulation that if the Young's modulus or mass density of a shaft of a cue is large, the ball trajectory immediately after the impact is deviated largely and then is curved with a large curvature. Because the extended method can evaluate quantitatively this kind of effects of material properties, it is useful for a design of a cue.

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In a steel process line, shape controller of steel strip which use an electromagnet are important devices which improve strip quality and line speed. It is confirmed that the devices are beneficial when these are applied to continuous galvanizing line (CGL). However, it is necessary to avoid a static instability phenomenon by the negative spring of the electromagnet, and a spill-over phenomenon to be caused by the high gain of the control system in this device. We proposed the analysis model combining the control system with the steel strip. The model was applied to a real machine to confirm the availabilities. Moreover, this paper discusses the static instability phenomenon and the spill-over phenomenon.

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A number of different structures in industrial facilities are installed on supports. There is the case that the damage occurs by the coupled vibration. The response magnification is obtained from the modal natural frequency and the modal damping ratio of the coupled system in the seismic design. Therefore, the modal natural frequency and the modal damping ratio of the coupled system are required. The natural frequency and the damping ratio of the support and the structure are abtained during the initial design process or by a shaking test. However, the modal natural frequency and the modal damping ratio of the coupled system are not easily obtained. The modal natural frequency of the coupled system can be calculated from theoretical equation, but the modal damping ratio cannot be easily calculated. In the present study, an equation to calculate the modal damping ratio of the coupled system with classic damping is presented. In addition, a simple equation to calculate the modal damping ratio with a non-classic damping system is proposed. This equation is evaluated theoretically. The proposed equation is useful for obtaining the modal damping ratio without performing eigenvalue analysis or a shaking test.

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One of the authors has proposed an adaptive nonstationary control (ANSC) method and its applications to positioning control of vibration systems. In that control method, the time-varying feedback gains are obtained by online computations of a time-varying Riccati equation taking the parameter variations of the controlled object into account. However, the previous paper discussed as the state feedback control method. Its improvement to the output feedback control method is one of important issues for actual applications. Generally, the output feedback controller of the optimal control includes Kalman filter as the observer. However, the use of Kalman filter for the ANSC method requires much computational load in actual implementations because it is designed by another time-varying Riccati equation. Therefore, this paper proposes a practical output feedback control method of ANSC without Kalman filter. The proposed method corresponds to a two-degree-of-freedom control system which consists of an online simulator and a sliding mode controller. This structure enables us to reduce the computational load. The effectiveness of the method is verified theoretically and experimentally.

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In this paper, we applied the Direct Adaptive Algorithm (DAA) to active noise control (ANC) of low-frequency impact noise with a dominance at the 63 Hz to 125 Hz. DAA can carry on the adaptive feedforward control without identifying the acoustical property of a secondary path. It can also reduce the noise even if the control position moves. We develope an impact noise generator for the experiment. A control effect is rated with difference of sound exposure level. From the simulations, an enough validity of control is shown after ten times of impact. The possibility of using ANC against the impact noise is shown from both the simulations and experiments.

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It is commonly recognized that characteristics of damper assembly significantly affect to vehicle dynamics. However, approach to understand its dynamic characteristics is dependent on physical testing, and effects of each component are hard to examine in detail. Therefore, the main subject of this study is to develop a method which gives easy way for designers in examining each component of damper assembly. Conventional analytical method of equivalent linear system using the restoring force model of power function type was modified and applied to damper assembly modeling. By comparison between analysis and experiment of vibration response, the validity of this modeling method was confirmed.

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Steer-by-wire (SBW) system, in which the conventional mechanical linkages between the steering wheel and the front wheel are removed, is suited to active steering control, improving vehicle stability, dynamics and maneuverability. With conventional controller for SBW system, it is difficult for driver to feel reaction torque exactly from steering system. In this paper, a new SBW system using bilateral control designed by passivity approach is proposed. At first, conventional bilateral control scheme using disturbance observer is outlined. Secondly, a novel bilateral control with passivity is introduced. We also examine performance of the proposed control scheme and compare with conventional bilateral control scheme. The effectiveness of the proposed method is demonstrated by experiments with an electric vehicle.

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In this paper the evaluation of vehicle stability affected by different road surface coefficient is shown using state plane analysis method. The motion of a passenger car was calculated, using a half-car model and nonlinear equation of motion. The side forces between tire and road surface were calculated using magic formula. Vehicle side slip angle-Yaw rate phase plane trajectory was drawn for those conditions. The stable zone is confirmed become wider on permeable pavement than dense graded pavement, this effect grows larger at high speed.

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This paper deals with the effects of axle misalignment of a truck with independently rotating wheels (IRWs) on the wheel lateral force and the flange wear. Since the truck with IRWs lacks for self-steering ability, it is concerned that the wheel continues flange contact with rail due to the effects of axle misalignment in parallelity and the flange wears rapidly under the continuous flange contact condition. Numerical simulations are carried out, using an analytical vehicle model with the axle misalignment. Obtained results are as follows : Even if misalignment is a little, the vehicle with IRWs which dose not have self steering ability tends to run under the flange contact condition, and then continuous lateral force acts between the flange and the rail. The vehicle with IRWs, which has axle misalignment only in the lateral setting, does not have tendency of continuous flange contact. In the range of misalignment in parallelity considered in this paper, the wheel lateral force increases with the increase of the misalignment, and the wheel lateral force of IRW increases more than that of the solid wheelset. The wheel lateral forces generated due to the misalignment are equivalent to the ones generated in the curved tracks, the radii of which make the attack angles corresponding to the misalignment.

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Some important parameters are called the camera parameters. They include the principal point, which is the intersection of the optical axis of a camera with the image plane, the principal distance, which is the distance between the center of the lens and the image plane, and the length of 1 pixel on the image plane. The information of the line of sight used for 3D measurements is obtained by transforming the position of the object's image using the above described camera parameters. Highly accurate 3D measurements are required to calibrate the camera parameters. In a 2-plane calibration method, a calibration fiducial chart containing fiducial points, whose positions on the plane are assumed to be known, is moved in the depth direction, and pictures of the calibration fiducial chart are taken before and after the motion. Here, position and orientation errors of the fiducial chart, referred to “setup errors” in this paper, greatly affect calibration accuracy. In this paper, the authors formulate the relationships between the setup errors of the calibration fiducial chart and calibration accuracy.

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For further improvement of indoor environments concerning air and noise pollutions, ventilation is one of the key factors. In this study, we develop the measuring technique of unsteady pressure on a rotating blade surface, to reveal the basic features of a cross-flow impeller. Specifically speaking, we consider the simplest model as the fundamental study, namely, the flow around the cross-flow impeller rotating with flat-plate blades in open space without any casings. On this impeller's blade, we measure the fluctuating pressures, which are discussed in comparison with flow visualizations with the particle-image velocimeter (PIV), velocity measurements by a hot-wire velocimeter (HW) and numerical simulations. As a result, by the compensation of the centrifugal-force effect, we get accurate pressures on the rotating blade, which are conditionally-averaged over a number of periods. The obtained experimental results can be also dedicated to CFD as standard benchmarks.

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This paper proposes the parallel mechanism mobile robot whose body is a parallel mechanism. Its notable feature is that it can elevate another mobile robot to a high level to which the latter alone cannot ascend. In serial manipulators, the weight of actuators for distal joints is a load on actuators for proximal joints. On the other hand, actuators support the output platform of a parallel manipulator in parallel. Therefore the parallel mechanism body can elevate a heavier object than a serial manipulator without elevating most of or all of its own actuators. In addition, the output platform can be made wide enough to load another robot. As an example of such a parallel mechanism mobile robot, we develop a four-DOF parallel mechanism mobile robot. Its advantage is that the platform can be kept horizontal in rough terrain. We experimentally verify that the robot can elevate another mobile robot of almost the same weight.

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Lunar rovers are required to move on rough terrains such as in craters and rear cliffs where it is scientifically very important to explore. In the past, wheel typed rovers are popular for planetary exploration missions. However, there is a problem that the wheel typed rovers have possibility of stack. Therefore, this paper investigates a mechanism of kinetic behavior between the wheels of the exploration rovers and soil. The important parameters are extracted by considering the mechanism. This paper proposes an elastic wheel by considering the important parameters. The elastic wheel has the surface which can be changed flexibly toward rough terrain. Running Experiments on soil which imitated Regolith are carried out to observe the traversability of the elastic wheel using slip ratio and sinkage.

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In our research, we consider of applying the swing of human's arms to the mechanical elements of a jumping machine. We call such a jumping machine 'Pendulum-type Jumping Machine'. In this paper, a pendulum-type jumping machine which consists of three links and two motors is constructed. One of three links is treated as the body of the jumping machine and the others are treated as its arms. The jumping machine can jump up to a step by swinging arms cooperatively. We introduce the scheme of soft landing so that the jumping machine can land on the step without tumble. The posture control problem of a free-flying system is explored to achieve the soft landing by the jumping machine. Then the ability of ascending stairs by the jumping machine is demonstrated through experiments.

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Conventional sensor-based navigation algorithms for mobile robot such as Tangent Bug algorithm work only for stationary obstacles. When a mobile robot is operated in more general unknown environment, moving obstacles such as human should also be considered. In this paper, a navigation algorithm which works for moving obstacles and stationary ones with unknown environment is proposed, using a new idea that distinguishes moving obstacles from stationary ones with distance information by sensor of mobile robot. The idea is based on the definition of an inclination angle on the wall surface that is called the wall surface angle. The wall surface angle of each step is accumulated while following the boundary. When the difference between the total accumulated angle and the initial one that is the rotation angle of the robot is over 2π radian, currently following obstacle is recognized as a moving obstacle. According to this idea with Tangent Bug algorithm for stationary obstacles, the navigation algorithm for moving convex shaped obstacles is constructed. In this paper the effectiveness of this algorithm for moving obstacles is shown by simulations.

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We propose a strategy for handling a large object by cooperation of multiple PID position-controlled manipulators and develop a cooperation system consisting of three commercial industrial robots. The developed system can handle a large object by cooperation of three robots. Three passive joint mechanisms consisting of four passive joints with electro-magnetic brakes are installed at the tip of each robot to avoid excessive inner forces due to mutual positioning errors. Since the geometrical relationships among three installed mechanisms and their joint angles must satisfy necessary kinematic conditions to avoid excessive inner forces, a simple way to check whether the necessary condition is satisfied or not is proposed. In order to investigate the effectiveness of the proposed strategy from the practical point of view, some fundamental experiments are done by using the developed system. Three 6 d.o.f. robots (Mitsubishi RV-E 3-ST) are open loop controlled by just a position commands which are calculated through inverse kinematics based on a desired trajectory of a handled object. From the results of experiments, the proposed strategy is confirmed and its effectiveness is verified.

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In the previous study, a cooperative control algorithm was proposed for a finger-arm robot composed of a 3 DOF finger robot and a 6 DOF arm robot. However, free movement of the robot was only discused in the previous study. This paper describes a control method for a finger-arm robot in order to simulataneously achieve the manipulability control and the impedance control in a three-dimensional space. Firstly, the control loops of the passive impedance control and the active impedance control are developed by using the previous heuristic method, and the experiments are made to examine their features and effects. Secondly, the algorithm of the steepest ascent method to control the manipulability of the finger robot is also proposed for the impedance control. The effectiveness of the proposed method was shown in the optimization process of the manipulability. The proposed method gives advantages of enlarging the impedance space, singularity avoidance and avoidance of unexpected obstacles.

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A McKibben artificial muscle is a good candidate as an actuator of man-machine systems although it has quite slow response. This study proposes a control method, which integrates feedforward control and feedback control, to achieve rapid response. The feedforward input is given from a database acquired by global identification since a robot arm with McKibben artificial muscles has a complicated model. An identification error is mainly caused by mechanical hysteresis on the McKibben artificial muscle. Therefore, a technical solution to reduce the effect of mechanical hysteresis is introduced. Experimental results show that the convergence performance is much improved by the proposed method. Input shaping by a sin curve reduces oscillation and further improves the convergence performance. The main issue of the method is that it takes much effort for the global identification on many sample points. Hence, experimental results with reduced number of identification points are shown and their control performances are compared.

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This paper provides a new approach of manipulability for robotic manipulators. While conventional manipulability is analysis in velocity domain and can not include force effect such as gravity of link and payload, the proposing approach can include the force effect. For the purpose, an operation range is introduced. The operation range is for actuator attached with every joint of manipulator and provides generable joint torque and velocity and their relation (between generating torque/velocity and addable velocity/torque). Using the operation range, we develop a new manipulability in velocity domain, including force effect.

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This paper presents a new hand motion assist robot for rehabilitation therapy. The robot is an exoskeleton with 18 DOFs and a self-motion control, which allows the impaired hand of a patient to be driven by his or her healthy hand on the opposite side. To provide such potential that the impaired hand is able to recover its ability to the level of a functional hand, the hand motion assist robot is designed to support the flexion/extension and abduction/adduction motions of fingers and thumb independently as well as the opposability of the thumb. Moreover, it is designed to support a combination motion of the hand and the wrist. The design specifications and experimental results are shown.

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To clarify the movement of the standing up assistance chair and correspondence with the sense side of the user in this research, it considered it based on the result of the senses examination experiment. As a result, in the superiority or inferiority judgment of the influence that the movement pattern on the seat with the difference exerted on the person, there was a common criterion to the person, and it was guessed that it was an anxiety. Next, to examine the relation between the movement orbit on the seat and the user's posture change, the operation measurement experiment was done. Based on those results, the relation with rise on the seat and user's psychological senses was considered. Result, to decrease the anxiety according to the movement on the seat, the suggestion that it was important to reduce the change of the angle of the knee, and to reduce the spine curve angle change, and to support the body by the area with a wide seat, and to support a lot of weight by the seat, and to slow down the movement of the seat load center was obtained.

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Thermal and residual stresses induced in transparent thermoplastic resin during laser welding process are analyzed by photoelastic method in order to discuss the relationship between residual stress and welding strength. Photoelastic fringes indicating contours of the principal stress difference showed that stresses caused by thermal expansion and contraction appeared at the welded portion, but they disappeared gradually after irradiation of laser. At the same time, new residual stresses appeared near the edge of the welded portion. Numerical simulation at a welding edge with normal and tangential stresses indicated a similar profile of principal stresses difference as that shown in the experiment. The welding strength monotonically increased with the degree of fringes at the edge of welded portion.

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The relationship between acoustic emission (AE) signals and tribological phenomena in the elementary processes of friction and wear is examined. The elementary processes of friction and wear were observed by a frictional surface microscope which installed a friction system into the view of an optical microscope. In this paper, the elementary processes are focused on the plastic deformation of the friction surface and the formation of wear particles between friction surfaces. In-situ experiments with the frictional surface microscope were performed by a pin-on-block type sliding test for iron and zinc. The friction surface and its side face were also observed by an atomic force microscope. The results show that two kinds of AE signals, a continuous AE signal of low amplitude and a burst AE signal of high amplitude, are detected in the elementary processes of friction and wear. The continuous AE signal of low amplitude is detected by the generation of slip-lines and wear elements. The burst AE signal of high amplitude is detected by the formation of a transfer particle.

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The effect of the rise in tooth temperature on tooth bending strength is not considered in the calculation of load capacity of plastic gears. The tooth temperature of a plastic gear greatly rise with the rise of heat due to tooth flank friction and hysteresis. However, calculation of tooth bending strength of a plastic gear does not include the effect. In the present paper, the temperature-rise factor is discussed. It will be incorporated in calculation of tooth bending strength of a plastic gear to include the effect. Three-dimensional analyses of heat generation and conduction in plastic gear pair were performed using a developed computer program, and the calculated tooth flank temperatures were compared with measured ones obtained from experiments with POM gears with various facewidths.The temperature-rise factor was proposed in basis of these calculated and measured tooth temperature and thermal behavior of the allowable bending strength of the material.

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This study aims to fabricate three-dimensional microstructures on a silicon surface using focused ion beam (FIB) irradiation and wet chemical etching. A silicon surface irradiated with FIB withstands etching in KOH, and consequently protruding structures can be fabricated on the irradiated area. Three-dimensional fabrication is possible by taking advantage of the change in the etch stop effect duet o irradiation conditions.To fabricate higher structures efficiently, height dependences on various fabrication conditions were investigated.As a result, the height of the structures can be controlled by ion dose, in spite of the higher dose condition.A hard-to-etch mask was formed by preventing the channeling effect.Higher structures were fabricated with shorter etch time at the high-temperature conditions.Etching selectivity increased at high dose and low etchant concentration. These results enable us to fabricate higher structures efficiently.

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Formerly, the joining method between a short pipe and elbow tubes of steel pipes had been applied to a manual welding process. This work tried statistical controlling methods of fitting size accuracy between a short pipe and elbow tubes, and improvements of its process to apply to a welding robot. These statistical controlling methods and improvements could apply to the automatic welding process of that both pipes joints, instead of a manual welding. Also, these methods and improvements get the fitting size of weld joints with high reliability and accuracy with representation. Therefore the system of welding robot for short pipe-elbow tubes joints could realize a production process with high accuracy and high productivity.

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In order to enable optimization of the kinemetic calibration condition of a robot considering its task, we proposed an estimation method of output pose error after calibration and the error evaluation index. The index is derived from linearization of relationship between output pose error and measurement error. It depends on kinematic parameters of the robot, calibration condition and error evaluation condition specified by the task. Simulations considering measurement error for the Stewart platform, one of the six-dof parallel robots, were conducted to clarify the relationship between the proposed index and positioning-error after calibration. Effectiveness of the calibration condition obtained by the proposed index was confirmed through comparison with conventional method. Results of experiments using a Stewart platform were shown to support the proposed method.

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This paper proposes an optimum system design method that especially considers product lifecycles, and aims to help designers make effective decisions during the product design phase. By considering and estimating all lifecycle factors of cost and environmental impact in addition to the performance of the product, this method facilitates development of optimum design solutions that incorporate requirements pertaining to the product's entire lifecycle. Furthermore, quantitative estimation of lifecycle factors enables the numerical expression of optimum solutions, rather than depending primarily on experiment and designer intuition. To demonstrate the effectiveness of the proposed method, this paper develops an optimum system design method considering product lifecycles for a milling machine as an example of a machine product designed for long term use. The lifecycle cost and the lifecycle environmental impact are generally expressed as the summation of each value during manufacturing phase, usage phase, disposal phase, and recycling phase. In this example model, Eco-indicator 99 is used to evaluate environmental impact. In the proposed lifecycle design optimization method, the relationships among the product performance, the lifecycle cost, which includes the manufacturing cost, and the lifecycle environmental impact are evaluated as a multiobjective optimization problem. Obtaining a Pareto optimum solution set and analyzing it help designers to get clues for breakthrough of the product design.

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