The purpose of this study is to control the myoelectric prosthetic hand that can grasp various objects stably. The electromyogram (EMG) signals of the flexor and extensor muscle of the forearm were recorded by subjects who performed two movements of the digital flexion and extension in a maximum voluntary contraction. The integrated EMG (iEMG) and mean power frequency (MNF) were calculated from the recorded results. The difference values of iEMG and MNF between the start and the end of the movements were calculated. In the movement of the digital flexion, the difference value of iEMG in the flexor was smaller than that in the extensor, and the difference value of MNF in the extensor was smaller than that in the flexor. In the movement of the digital extension, the difference value of iEMG in the extensor was smaller than that in the flexor, and the difference value of MNF was low in both muscles.

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Human safety is one of the most important issues in human-friendly robotics. We have proposed and developed the safety device to guarantee the safety for humans in the robot's workspace. The safety device consists of only mechanical components without actuators, controllers and batteries. In this paper, the effect of the vibration of the robot on the performance of the safety device is experimentally examined

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The measurement of ground reaction forces is important in the biomechanical analysis of gait. The author has proposed and developed a wearable sensor system that measures ground reaction forces of humans by using flexible tactile sensors. In this paper, the dynamic response of the sensor system is experimentally examined. From the experimental results, the usefulness of the sensor system is discussed.

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Physical therapy is important for rehabilitations, a student who wants to become a physical therapist acquires the skill of physical therapy by clinical training. To adopt first training stage of rehabilitation, we are developing a simulator system for a cubital joint. This simulator is needed to realize the same condition of patient's joint moving, we are training to use a MR brake to generate the braking action of joint. In this report, we describe the simulator system construction and results of basic experiments using MR brake and actuator.

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We have developed a simple self-transfer aid robotic system. The users targeted are people with impaired walking ability who use a wheelchair, however are still able to walk to some extent. With the aid transfer, these users can maneuver themselves independently to and from apparatus, in this case, toilets. In this paper, we will explain the horizontally moving mechanism.

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A new health care system using a simplified robot face has been developed. Patient's health care data can be stored in a personal computer and a robotic system can take many actions depending on the stored data. It can tell a patient what time to take his/her medication and warn them if they fail to take their medication at the appropriate time. The robotic system can communicate with a patient using facial expressions, a voice communication system and a personal computer monitor. The robot face was designed using simple mechanisms in order to achieve a low cost system. In this paper, the experiments on human facial expressions are conducted in order to improve our simplified robot face used for a health care system, and the simple robot face is fabricated regarding the experimental results.

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This paper proposes the newly developed safety driving system aimed for the use of electric wheelchairs. The proposed system obtains the wheelchair position using a GPS receiver, and then the detected position is added on map. By using the information with GPS position and map, wheelchairs user can understand their situation on the road. The experimental results on the GPS position detection and its accuracy were discussed in this paper.

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We are developing a manipulator system in order to support disabled people with less muscle strength such as muscular dystrophy patients. Such a manipulator should have an easy interface for the users to control it. We are developing a user interface part of the system. A single switch is introduced as the input device for the manual control of the robot arm in our interface. The scanning menu panel is designed to perform various actions of the robot arm with the single switch. In this paper, we report the development of RT-Component of iArm which is a commercial manipulator to support disabled persons' daily life to evaluate our interface's efficiency. The demonstration that the user interface and the iArm components are connected and controlled is shown.

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To mitigate axial tensile stress at the inner surface of a pipe butt joint, heat sink welding is widely used to fabricate the joint. The inner surface of the pipe is cooled by water during the welding operation. To mitigate the axial tensile stress more effectively, we developed a new welding method in which a water-shower cooling process is applied behind the welding torch on the outer surface of the pipe subjected to the heat sink welding. When this method is applied in the fabrication of pipe butt joints, both heat input quantity and the distance between the torch and the water-shower cooling area mainly determine to what degree the axial tensile stress can be mitigated. To determine these conditions for mitigating tensile stress, we first used the finite element method (FEM) to evaluate the effects of these conditions on residual stress. The FEM results indicated that residual stress decreases to compressive stress when the heat input quantity is 15 kJ/cm and the distance between the torch and the water-shower cooling area is less than 15 mm. To verify the validity of the FEM-obtained conditions, a pipe butt joint was fabricated using the new method. Residual stresses on the inner surface of the joint were then experimentally measured. These measurement results agreed well with the results of FEM analyses. It can therefore be concluded from these analytical and experimental results that applying water-shower cooling during welding effectively mitigates axial tensile residual stress.

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The 4-point bending tests were carried out and microfracture process in cermet was characterized by acoustic emission (AE) technique. During the test, rapid increase in cumulative AE energy prior to the final fracture was observed, which could be related with the maincrack formation using AE source location. Furthermore, AE wavelet analysis was performed to characterize the signals and the results suggested that there were two types of AE; one is the burst-type signal with high frequency and the other is continuous-type signal with low frequency. Considering their natures, the former could be related with microcrack nucleation or propagation, and later with plastic deformation of binder phase. In addition, the relationship between the critical stress for maincrack formation and preexisting-defect size was investigated, and it was found that the crack initiated from the defect at the rapid increasing point of cumulative AE energy.

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Quantitative detection of microcracks during fracture process of alumina was carried out by AE source characterization which yields the quantitative characterization of the size, nucleation velocity and fracture mode, as well as nucleation time and location of individual microcracks. The fracture tests of two types were carried out. The 4-point bending test was carried out to understand the maincrack formulation process in the ceramics. The fracture toughness tests of SENB specimens were carried out in the air and the water to understand the maincrack propagation process. Then AE source function which describes the nature of microcrack nucleation was also determined by inverse calculation using detected signal. Consequently, in the maincrack formulation process, intergranular microcracking with the size of about 12 gm became the fracture origin. Furthermore, in the maincrack propagation process, it was clarified that the size of microcrack in the water was larger than that in the air and larger microcracks nucleated in the water resulted in the degradation of fracture resistance.

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When designing gas turbines for power plants that use fossil fuels it is necessary not only to consider environmental impacts, but also to improve estimation accuracy for both strength and vibration. We developed a new evaluation method, using a vibration exciter, for use during the design process. Our results show that as shank pin load, shroud cover load, and centrifugal force load increase, the damping ratio of the turbine bucket decrease. In our tests the damping ratio decreased by as much as 30% as shank pin load increased, up to 50% as the shroud cover load increased, and up to 30% as centrifugal force load increased. Consequently, the vibration characteristics of a turbine bucket can be evaluated by the method described herein.

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Since there are many earthquakes in Japan, it is necessary to protect a human life and property from the damage. One of the building collapses due to the earthquake occurring resonance of the building because an earthquake frequency is corresponding to the natural frequency of it. Then, it is important to know the natural frequency of the building. This study was analyzing of the natural frequency of the building by finite element method. Two kinds of models were presented for the analysis.As the results of the analysis, the vibration modes with the torsional modes were obtained, the first natural frequency by the analysis shows the good agreement with the experimental one.

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This paper presents a FEM program for two-dimensional elastic problems based on the 8 point iso-parametric element. Today, current commercial FEM programs have been used as a versatile tool for simulating engineering problems. However, most of the programs have many commands and FEM beginners are sometimes puzzled as to how to use the commands. While the versatile FEM program is very powerful, the program requires not only computer resources but is also quite expensive. Therefore, we will propose a new compact FEM program for FEM beginners. Our FEM program has GUI interface on pre-post processing and is so designed to have various user-friendly interfaces.

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The purpose of this study is to obtain the fundamental feature of perforated plate under the load-controlled low-cycle fatigue and creep-fatigue condition. The hysteresis-loop and the crack propagation were measured during the test to examine the relation between crack propagation and the history of strain. And the Stress Redistribution Locus (SRL) method is applied for estimation of stress concentration in order to predict fatigue and creep-fatigue life for the specimens. It was found that the strain varies with increasing number of cycle. In the latter of cycle the strain increased sharply. It was shown that the life evaluation can be more accurate using the strain obtained by applying SRL method. Additionally, it was shown that the life evaluation using crack initiation cycle is more accurate than that using failure cycle.

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This study measured the crack growth in perforated plate of SUS304 stainless steel by a creep fatigue test as a clue to evaluate the creep fatigue characteristic that a structure member is under the elevated temperature. It was measured that the crack length by using photographs which were photographed with the CCD video camera at a constant frequency. From the measurement, it is found that the total crack growth rate of a creep fatigue increases sharply with the passage of time or the growth of cracks. And cracks grow up at both sides around the hole, but the growth of each crack may not be symmetric. Even if the diameter of the test specimen changes, J- integration can be applied.

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This paper provides an evaluation of fracture behavior and fracture toughness on single crystal silicon wafers. Fracture toughness (K_<IC>) were measured on the major planes of single crystal silicon using both method of indentation fracture (IF) method and controlled surface flaw (CSF) at room temperature. The values of K_<IC> on the surface orientations {100}, {110}, and {111} obtained by IF method were found to be 1.31±0.13, 0.84±0.14 and 1.16±0.13 MPa・m^<0.5> respectively. K_<IC> on the surface orientation {111} obtained by CSF method depends on indenter profiles.

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This paper provides an evaluation of fracture behavior and fracture toughness on single crystal silicon wafers. In this study, fracture toughness (K_<IC>) were measured on the major planes of single crystal silicon using indentation fracture (IF) method at room temperature. The values of K_<IC> on various major surface were obtained by IF method. It appears that K_<IC> on each surface orientation increases slightly with increasing elastic parameter including Young's modulus and Poisson's ratio Poisson's ratio.

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Soft magnetic composites have the characteristics that iron loss is low at the range of high frequency and complicated three-dimensional shapes are formed easily and strength and magnetic characteristic of soft magnetic composites become well as their densities are high. As analysis technology to support the design method for the longer life dies and the press forming method for the more dense composites, we applied the Cam-clay model, which could treat quality of soil materials as a continuum, to press forming analysis of powder materials and studied a method to identify the material property parameters by lateral pressure measurement examinations of the powder made of pure iron.

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