A synchrotron radiation X-ray micro-tomography system called SP-μCT with a spatial resolution of about 1μm has been developed in SPring-8. In this work, SP-μCT was applied to the nondestructive observation of fatigue crack propagation appearing due to thermal cyclic loading in lead-free solder joints of chip type resistor. In order to show the whole image of crack propagation process, 3D rendered images of fatigue cracks was extracted from CT images. The results show that nondestructive inspection of lead-free solder joints of chip type resistor by the micro CT system is useful in combination with three-dimensional visualization of the thermal fatigue cracks.

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This paper proposes a robust topology optimization method for a linear elasticity design problem subjected to an uncertain load. The robust design problem is formulated to minimize a robust compliance that is defined as the maximum compliance for the worst load case of an uncertain load set. Since the robust compliance can be formulated the scalar product of the uncertain input load and output displacement, the idea of "aggregation" used in the field of control research is introduced to evaluate the value of the robust compliance under the uncertainty of input load. Aggregation is to represent the direct relationship between the uncertain input load and output displacement by a small linear system composed of these vectors and the reduced size of a symmetric matrix in the context of a discretized linear elasticity problem using the finite element method. According to the Rayleigh-Ritz theorem for symmetric matrices, the robust compliance minimization problem is formulated as the minimization problem of the maximum eigenvalue of the aggregated symmetric matrix when Euclidean norm of the uncertain load set is fixed.

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A new design method using topology optimization technology is proposed. In the concept design stage, the result of topology optimization is directly taken in following performance analysis to predict performance-mass relation. Optimum concept model shape for detail design is determined easily by the performance-mass relation. The method was applied to a design of a forged-aluminum suspension member, a 10% mass reduction and about two-third of reduction of detail designing man-days were affirmed comparing to conventional design.

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In this paper, we present a shape optimization method for plate springs, which is based on the free-form optimization method for the shape design of shell structures we have developed. With the free-form optimization method, an optimum shell with smooth free-form surface can be obtained without any shape parameterization, In order to apply this method to the design of plate springs, we introduce a squared displacements error norm at the loaded points as the objective functional to control the displacements to the desired ones. It is assumed that the shell was varied in the normal direction to the surface and the thickness is constant. A non-parametric shape optimization problem without a volume constraint is formulated, and the shape gradient function is theoretically derived using the material derivative method. The shape gradient function is applied to the shell surface as the pseudo traction force to change the form. The calculated results show the effectiveness of the proposed method for the optimal free-form design of the plate springs.

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In this paper topology optimization of the periodic structure of sub-wavelength hole array that have specified optical characteristics is presented. The research of sub-wavelength hole array in an opaque metal film attracted many researchers by its special transmission spectrum. Such special transmission spectrum is induced by combination of coupling of evanescent wave and propagated wave and surface plasmon resonance. Recently, it was reported that the transmission spectrum can be changed not only by size and periodicity of hole array, but also by shape of hole. However, the systematic design method of hole array structure for desired transmission spectrum is yet not proposed. Here, we propose topology optimization method to design hole array structure to obtain desired optical characteristics.

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This paper presents an approach to minimize weight of suspension parts while keeping the fatigue strength base on a non-parametric boundary shape optimization theory. As an index for the fatigue failure, we considered the frequency processing stress or strain in a suspension part evaluated from actual loading history. To avoid the irregularity coming from using the local value for constraint functional, we used Kreisselmeier-Steinhauser functional of the frequency processing stress or strain. For reshaping, we employed the traction method to keep the smoothness of original boundary. To reduce computational time, we used many PC clusters for analysis about actual loading history. By our approach, we obtained about 8% weight reduction of a suspension part while keeping the maximum value of the frequency processing stress or strain constant.

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This paper presents a numerical solution to multipurpose shape optimization problems of steady state viscous flow fields. In previous study, it has been dealt with drag minimization problems and lift maximization problems for an isolated body located in uniform flow in viscous flow fields. In this study, multipurpose shape optimization problem using normalized objective functional is formulated for the drag minimization and the lift maximization. Shape gradient of the shape optimization problem was derived theoretically using the Lagrange multiplier method, adjoint variable method, and the formulae of the material derivative. Reshaping was carried out by the traction method proposed as an approach to solving shape optimization problems. The validity of proposed method was confirmed by results of 2D low-Reynolds number viscous flow problems.

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The Differential Evolution (DE) is one of the meta-heuristic methods and finds a global minimum to continue mutation, crossover and selection. It has been reported that the DE can find a global minimum of non-convex and continuous functions with high certainly. However, the reason why the DE can find a global minimum has not been discussed. In this paper we examine the similarity to the Particle Swarm Optimization (PSO). As a result, we examine the reason why the DE can find a global minimum. The performance of the DE is shown by applying to some benchmark problems and comparing the results with the PSO.

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In this paper, a hybrid optimization technique for plant layout design is proposed using a genetic algorithm (GA) and a particle swarm optimization (PSO). It globally searches for the layout solution based on the coding rule to the GA in the discrete design variables. Then, the automatic placement and adjustment of plant layout is carried out to obtain the real global optimal solution using the PSO in the continuance design variables.

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Recently, finite element method (FEM) is effective in sheet metal forming and used in springback simulation. Springback is one of shape defect and it produces angle variation after removing tools. Its simulation is influenced by many parameters, material properties, blank holder force (BHF), friction coefficient, and any more. In this paper, we researched the influence of BHF to springback with FEM.

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In this paper, we present results of numerical experiments for 3D reinforcement corrosion shape estimation problem based on observed temperature on concrete surface. As for the technique of numerical simulation, the finite element method is introduced. In addition, the adjoint variable method is employed to obtain the shape of reinforcement corrosion such that computed temperature is close to the observed temperature. In this study, we investigate the dependency of obtained reinforcement corrosion shape with respect to initial shape which is given as the initial value in the shape determination problem.

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ITS technologies are expected to be applied to not only VICS and ETC, but also vehicular safety systems. The vehicular safety system supports driver's cognition and reduces traffic accidents. To test the effectiveness of the systems by simulation, the coordination of multiple simulators such as a radio propagation simulator, a network simulator, and a traffic simulator is needed. And in the traffic simulator, the cognitive process of each driver should be modeled precisely. This paper describes the overview of ITS integrated simulator and improvement of the microscopic traffic simulator considering driver's visual cognition.

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According to the development of computer abilities, the simulation techniques are widely used in automobile areas instead of actual experiments. In this paper we describe the overview of various simulation techniques those are related to traffic flow, body structure, human model, casualty estimation, and others. Next we introduce the "ASSESS - A Survey Simulator to Evaluate Safety Systems -", which we are developing to analyze effectiveness of active safety systems. The simulator includes driver model, vehicle model to simulate real traffic accidents or near-miss incidents at an intersection. The characteristics and perspective of the simulator are discussed.

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Transient behaviour of a passenger's body standing within a train at an accidental collision is estimated based on finite element method. The purpose of this study is to estimate the effects of facing direction and grip force on the behaviour of a passenger's body at the accidental collision. A passenger's body model and a train model are developed to proceed a numerical simulation within a short time.

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Cellular automata simulation of traffic flow near a branching point of roads is described in this study. Vehicles are molded to behave according to Chandler model (Single vehicle following model) and multiple vehicles following model. The simulation results show that the multiple vehicles following model can increase the traffic flow amount and that traffic flow amount in branching road is greater than that in non-branching road.

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We deal with a semi-active hump of which the height can be controlled by varying the resisting forces of semi-active shock absorbers according to the speeds and masses of vehicles passing over the hump. The shock absorbers have magnetorheological fluid, the resisting force of which can be varied by applied electric current. The shock absorbers are installed underneath the top of the hump. We propose a detection system which recognizes the masses of vehicles before passing over the hump. As a result of an experiment, we clarify that the detection system for semi-active hump was effective in recognizing the masses of vehicles.

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We compare a convex active hump to a concave active hump on the effect of controlling vehicle speeds by a simulation. The active humps can vary their heights adequately using hydraulic cylinders according to speeds and masses of vehicles passing over the humps. We introduce a new active hump defined by the following: a concave active hump of which the height can be varied only under the ground level. As a result of the simulation, we clarify that the concave hump was more effective than the convex hump with respect to controlling vehicle speeds.

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This report compares semi-active landing gears having magnetorheological fluid with conventional passive landing gears regarding to decent velocity variations and mass variations of aircrafts by a simulation. As a result of the simulation, it is clarified that the semi-active landing gear coped with effectively velocity variations and mass variations more than the passive landing gear do. The maximum descent rate of the semi-active landing gear was 0.8m/s higher than that of the passive landing gear when the mass of the aircraft is 40t. However, the maximum descent rate of the semi-active landing gear was lower than that of the passive landing gear when the mass is 130t and 85t

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The PDM and PLM systems with the authority data of 3D model (MBD) is going to be established worldwide. However, the model deformation through their workflow is coming out as the serious issue. Deformations happen while translation and archive of model data, and over upgrade of CAD systems. FAA requests the aviation industry to clearly define the checking process against this issue. We developed the validation tool for the issue. This paper describes the real examples of deformation problem in USA and Japan, analyzes the cause of deformation, and effectiveness of our validation technology.

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Automobile hub is important security parts. However, the failure accident is reported. In this study, rotating hub models was made from epoxy material, and the rotational load was given. And the stress freezing experiment is conducted; the observation of stress caused by the rotation in a stationary state is enables. And, the state of the stress of the hub was clarified by using the photoelastic method. The evaluation is obtained by the stress intensity factor and principal stress diagram.

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The application of the reliability-based optimization to the traffic problem is described in this study. The traffic amount is maximized on the condition that the traffic accident risk is kept under the value specified in advance. The traffic accident risk is modeled from the traffic data at the loop line in Paris. The results show that the traffic volume should be kept between 900 to 1500 vehicles/hour for reducing the traffic risk.

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Shape-memory polymers (SMPs) can be deformed above their glass transition temperature (T_g) upon the application of a small load. They can maintain their shape in a rigid form after they have been cooled to below T_g. When heated again above T_g, they return to their predefined shape. Exploiting these characteristics, we developed a McKibben actuator which can fix into a rigid shape without the need for continuous control using an SMP. When this new actuator is warmed above T_g, it can be used as a conventional McKibben actuator. When the actuator attains its desirable length, it can be cooled to below T_g and the SMP will fix the structure in a rigid, actuated, state. This state is maintained without the need for any air supply or control system. The enhanced versatility of this new actuator is shown through a series of experiments conducted on a prototype SMP McKibben actuator.

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The paper presents a novel microactuator using AC electroosmosis. On surfaces of AC voltage applied plate elecrodes that contact with dielectric fluids, the gathered electric charges form electric double layers. Due to the AC electric field, the charged particles form convection flow, which is called AC electroosmosis. The proposed actuator transforms the covection flow to a unidirectional flow with channel walls and the unidirectional flow drives an fluid power actuator. The proposed actuator features simple and miniaturizable structure, low driving voltage, stable drive without electrolysis, and wide variety of the drivable fluids. In this paper, the microactuator is proposed and a basic pumping device is fabricated and tested. Based on the measured results, the no-load flow rate is estimated.

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This report deals with a rock-crasher embedded in the science integrated package for future lunar exploration. The crusher measures 59×60×129 mm and weighs 490 g. The generative impact force and consumption power were 150 N and 6 W at a voltage of 24 Vp-p and a driving frequency of 50 Hz device. A tool bit with pyramids driven with a solenoid was made from tungsten carbide. Hard basalt, granite and anorthosite were smoothed.

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Three-axis tactile sensing has good advantages on grasping an object of unknown mass and hardness. We developed a new three-axis tactile sensor, which possesses a simple structure to endure large applied force caused by power grasp. Normal force distribution is measured according to gray scale value obtained by image data processing as previous three-axis tactile sensors. Shearing force distribution is determined by linear movement of image data calculated by optical flow. Sensing characteristics of the present sensor is dominated by configuration and material of conical feelers formed on a silicon rubber sheet. By mean of LIGA, we obtain a mold of the silicon rubber sheet In evaluation experiments, we applied vertical force and horizontal force to the sensor. We confirmed sensing ability of the present sensor to acquire normal and tangential forces. In design of tactile sensor, we utilize a USB microscope, which has a CCD camera and a light source.

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In order to investigate effects on presentation tactile-haptic reality, the authors developed a multi-modal display capable of simulating mechanoreceptors of fingers in addition to the muscle-tendons. The multi-modal display was constituted of a manipulator having three-degrees of freedom. The tactile display has a display pad of a 12-by-4 array of stimulus pins, which generates distributed pressure on a human operator's finger surface. Since this tactile display has relative large display pad, an operator can touch an object with three fingers by natural way. Vertical movement of virtual tactile pad in the virtual world is controlled by compressed forced applied on the display pad. The compressive force is measured by a strain load cell installed under the actuator array. The tactile pad simulated in the virtual world is moved in the vertical direction in proportion to the compression force. In order to evaluate this display, we are developing to puzzle game software, in which an operator manipulates 9 pieces block to arrange them to a specific configuration. We will verify presentation ability of this display according to efficiency of the manipulation.

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Recently, the need of colonoscopy is increasing because of the rise of colonic disorder including cancer of the colon. However, current colonoscopy depends on doctor's skill strongly. Therefore, a large intestine endoscope that does not depend on the technique of doctor with high safety is required. In this research, we aim at development of the device that changes own stiffness by air pressure and applying it to the large intestine endoscope that is possible to be inserted into the colon safety without techniques of doctors. This device consists of fiber-reinforced silicone rubber and is able to change the stiffness by air pressure. In this report, we increased reinforced fibers and introduced new drive system which used negative pressure by the improvement of the device. And we developed the prototype of the endoscope. We verified the effectiveness by insertion experiments in U-shaped route.

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A current many master-slave control system uses a large power source and a lot of sensors. Therefore, it is complicated, and a work place and time is limited. In this study, both characteristics of actuator and generator of a motor are used for an energy recycling. This system with only lightweight battery having force sense without force or motion sensor can be developed. By this, active rehabilitation training is carried out safely. In this report, it is shown that performance of the system is improved by using a motor characteristic or addition of a gear system from fundamental experiment. In addition, by simple control law, the velocity of a slave motor almost accords with a master motor.

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We reported a novel impedance control method based on a fractional calculation inspired by the viscoelastic properties of biomaterials such as muscle. This fractional impedance controller was found to realize superior impact absorption for the purpose of flexible contact for assistive and rehabilitation robots. This paper presents a preliminary evaluation of this concept using simulations. The numerical analysis results demonstrate that a fractional impedance controller has superior impact absorption performance than a conventional controller for contact with the elastic objects, especially for high stiffness objects and high velocity movement.

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Human safety is one of the most important issues in human-friendly robotics. We have proposed the safety device to improve the safety for humans in the robot's workspace. The safety device consists of only mechanical components without actuators, controllers and batteries. The safety device locks the robot's joint after detecting the overdrive on the basis of the joint's angular velocity. In this paper, first, the mechanism of the safety device is explained briefly. Second, the mechanism of the safety device is theoretically analyzed. Third, the safety device is designed and developed on the basis of the analysis results. Finally, the usefulness of the safety device is experimentally examined.

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New measuring and training system of muscle power for elderly seniors, that utilizes small 'electric generator' instead of 'spring force', was proposed. Our previous study clarified that this method can measure not only the muscle power, but also the reflection time and the muscle strength without any physical stress on old-old subject. This paper verifies that another advantage of employing electric generator. The advantage is that generator can electrically produce training loads for rehabilitation. Experimental results show the efficiency of the proposed training method.

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We have proposed and developed a walking support machine with the safety device, which provide a patient with partial body weight support and prevents the patient from falling. The constants force spring is used in order to provide the patient with partial body weight support. The powder brake, which can control the torque, is used as the device to prevent patient's falling. When a patient normally uses this support machine, the machine provides the patient with partial body weight support. After the machine detected the patient's fall, the machine prevents the fall applying the impedance control to the powder brake. In this paper, the usefulness of the brake by control method is experimentally examined.

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Among the elderly person, most of their injuries are reported to be caused by falling down with stumbling. It is due to their shuffling walking style resulted from deterioration of their dorsiflexion muscle force along with aging. Walking plays an important role in their independent day life. We aim at developing a wearable walking support shoes for a purpose of fall prevention of elderly people and to support walking rehabilitation training. A commercial product of Ankle Foot Orthosis is introduced and newly developed wire type pneumatic actuator is equipped on to support dorsiflexion motion during swing period at walking motion actively. In generally, these kind of active supporting systems require power source. We propose a driving scheme with no use of electric power, but with only potential energy of the wearer. Improvement of the devices toward embedding into a shoes is mainly reported here.

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Disuse atrophy in weightless environments such as prolonged spaceflight and bed rest are serious problems which hinder astronauts' or patients' health and reintegration into daily life. We proposed a "hybrid exercise" (HYB) against muscular and bone atrophy by using electrically stimulated muscles to provide resistance to the voluntary motion of a muscle undergoing training. Unilateral lower leg suspension (ULLS) of four weeks was carried out for young males as a simulation model of the weightless environment The HYB for healthy men increased muscle strength and bulk in flexor and extensor around the knee and elbow joints. The HYB for the ULLS group alleviated the atrophied symptom including the loss of the femurs' bone mineral density. Since the HYB requires only surface electrical stimulation on the skin, it can be applied ubiquitously not only to the serious problem but also to the shortage of exercise in daily life.

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When some handicapped people take meals by themselves, it is necessary to support them in order not to fail their eating. For this support, we are developing a robotic spoon, which controls itself intelligently and supports the user's eating. For the design, we took the movies of the eating movements of the handicapped people from three directions and analyzed their characteristics. The rotational angles and the moving velocities of the spoon were obtained, and their correlations with eating failures were investigated. From these results, we discussed the control method of the robotic spoon.

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Experiments have been carried out to elucidate the rise effect of human body temperature by corona nano mist sauna using the water fragmentation method. The effect of corona nano mist sauna is analyzed by comparing with the data obtained from the hot water bath and by solving the heat and mass transfer equation about human body. Temperature and relative humidity in corona nano mist sauna are 40℃ and 98%,respectively and temperature of hot water bath is 41 to 42℃. Time duration of bathing is 20 min for the both of corona nano mist sauna and hot water bath . The main acquisition obtained from the study is as follows that corona nano mist sauna brings it possible to promote the heat production from body by the increase of metabolism.

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To realize the rehabilitation for walk with a large knee flexion, the wearable type walk-assisting robot system has been developed. This system includes the walk evaluation system. In this report, to evaluate the gait stability, a calculation method which is based on the gravity-center fluctuation using standard deviation and the normalized method of a walk period is proposed. Especially, we evaluate the patient data of the Degenerative joint disease. So, using these values, it is clear that the difference of a walk state can be evaluated.

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In the contemporary society, people are subject to various mental loads resulting in stress, the so-called stress became a part of our lives that we cannot avoid. Therefore, the need for a device that can easily measure the stress in every day life is rising. In this research, Poincare plot and mental stress were visually evaluated using the cardiac beat-to-beat interval known as RR interval. It has been understood that the heart rate variability was concentrated in the lower left-hand side of the Poincare chart in the case of mental stress while it was overall scattered in the case of relaxation. Moreover, it was confirmed that a clearer difference could be shown by plotting the Poincare plot for RR intervals corresponding to the respiratory cycles.

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Conventional method for measuring the load to the intervertebral disk that causes lumbago is an invasive method to inserting the sensor into there directly. In this study, we propose a noninvasive estimate system for intervertebral disk load by measuring the deformation of the spine with the motion analysis system and using signal processing. Deformation of the spine is fitted to a circle using least square method. From the radius of the circle, we estimate gap length between 2 vertebras and evaluate intervertebral disk load. Estimated load using proposed method is compared well with the Nackemson's invasive experimental data.

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Cathepsin L (CatL) has been focusing as a biomarker for evaluating photo-stress. The purpose is to propose an on-site testing method of CatL in skin which can be used for the diagnosis of photo-stress non-invasively, easily, quickly and at any time. In this study, a novel immuno-chromatographic test-strip is proposed for CatL analysis in skin. In order to realize the disposable test-strip, colloidal gold technique was selected as the molecular recognition method of the CatL. The fabricated test-strip consists of a sample pad, a conjugate pad, a nitrocellulose membrane and an absorption pad. After dropping a sample, it required 90 seconds to reach the sample at the test line on the test-strip and indicated a red colored band 3 minutes later. The optical density was proportion to the activity of CatL. It was suggested that the test-strip might be used for the qualitative analysis of CatL in the stratum corneum.

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In this study, we propose an electrically powered wheelchair with an obstacle avoidance function for the physically handicapped person who cannot use a conventional electrically powered wheelchair. In the proposed wheelchair, a manipulation interface which is constructed by three buttons is mounted, considering the operability of the handicapped person. Furthermore, the obstacle avoidance function using ultrasonic sensors is newly equiped.

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We have been developing an original personal mobility "Tread-Walk 1". In Tread-Walk 1, walking velocity is detected on the treadmill and is amplified as driving velocity. Therefore, the user can expand his/ her activity area by walking movement. However, the user tends to be unstable in turn movement due to the centrifugal force. In this paper, we develop a safety turn movement algorithm by considering with walking position on the Tread-Walk. Moreover, the developed algorithm is evaluated using tape switches put on the handle of the Tread-Walk by three young subjects. The grasping time during turn movement is decreased by adding the developed algorithm. Therefore, the algorithm considering with walking position is more safety than that without waling position.

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Disabled people like those with cervical cord injuries have lots of difficulties, even when driving an electric powered wheelchair (EPW). Each device has its respective merits and demerits, but there is still a need to develop other types of operation devices. We have developed a mouthpiece type remote controller for those seriously disabled people. This remote controller would be inserted into a user's mouth and be operated by tongue. A control program for operating an EPW on the market was developed with two operation modes. They are "momentary mode: only while users keep pushing the switch, the EPW keep moving " and " Latch mode: a single switch push directs the wheelchair to move continuously for a period of time (adjustable in software)". The specifications of the third version mouthpiece type remote controller and the program were expressed in this paper.

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We have developed a one hand drive wheelchair with some assist functions generated by new manipulation mechanism and assist units. In this paper, to realize sure assist, we propose a new assist mechanism that the distance of rubber rollers doesn't spread during assist on, where rubber rollers translate the assist torque. Moreover, the assist effect to examinees with different manipulation abilities was verified by the running experiments using the one hand drive wheelchair equipped new type assist units.

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We have developed two kinds of power assistance suits. One is for support a patient's activities of daily living, which was united two apparatuses between for the upper limbs and for the legs; these were driven with a motor. These apparatuses were already developed, and characterized in that equipped person can be assisted for arms and legs without fixation with the apparatuses. By using this suit, we can input the entire body motion to the equipped patient for the neuro-rehabilitation. The other is for support a helper's assistance behavior, which was made with rubber belt, and without electricity. This suit can assist lifting motion, especially for equipped person's arms and waist. To confirm the validity of this suit, we measured the variation of maximum output force, IEMG and %MVC of the entire body while lifting and holding motion. By using this suit, the maximum lifting weight of equipped person was increased by 8kg, and the arm and leg of the equipped person were assisted effectively.

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When a designer finds or encounters a problem during design and development process, an effective way of ensuring the security and safety of the product is to identify all possible causes of the problem by Fault Tree Analysis (FTA) and fix them. Although FTA is an effective method, it is not easy for a designer to construct a complete fault tree without any misunderstanding or oversight. To solve this problem, the authors proposed a new design knowledge management approach called quantity dimension indexing. But, the approach is not effective to system fault which is extraphysical. In this paper, we propose a computer aid for FTA of system fault, constructing fault tree according to block diagram of system.

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We have defined XML schema of polishing case data, which are composed of material specifications, processing conditions, polishing material, machine specifications, and evaluation results. More than one hundreds parameters are dominant. Polishing process is repeated varying the associated parameters until fine surface is obtained. The structure of case data becomes complicated and difficult to handle. We proposed a effective method and examined it through inquiry examples and evaluated it to be applicable to manufacturing supporting method.

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