This paper investigates vibration suppression effect of tuned multi-mass damper with uneven weights Tuned multi-mass damper (TMMD) is made of plural tuned mass dampers (TMDs). It is already known that TMMD achieves higher vibration suppression effect than a single big TMD even the total weights of auxiliary masses of TMMD is equal with that of TMD. Besides, most studies about TMMD suppose that all the weights of auxiliary masses are even. In this study, a novel TMMD with uneven weights of auxiliary massess is presented and its vibration suppression effect is dealt with. Computer simulations are carried out and the possibility to enhance robustness of TMMD is suggested.

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Magneto-rheological materials are a class of smart materials whose rheological or viscoelastic properties can be varied by applying external magnetic field. MR elastomers (MREs) are the solid analogues of MRF and are expected to overcome the disadvantages of the fluid such as the particle deposition and the sealing problems. When such MREs are exposed to external magnetic field, the strength of the inter-particle force will change and thus their apparent elastic modulus is changed depending on the magnitude of the field. In this paper, the stiffness controllable elastomer composites known as MREs are first fabricated and their field-dependent static and dynamic properties are tested. The MRE is then applied to the vibration isolating mounts of 1-dof and multi-degree of freedom systems along with variable stiffness control scheme. Experimental investigations show that the vibration of both one-degree of freedom and multi-degree of freedom structures that are exposed to base excitation can be effectively reduced by the intermediating MRE mounts according to the semi-active on/off switching control algorithms.

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This paper demonstrates effects of harmonically varying damping on a parallel-coupled structure and the filtering using the Stuart-Landau equation. We applied the method of the harmonically varying damping to vibration mitigation of a single-degree-of-freedom structure with sinusoidal base excitation having two frequencies. In the study, an ideal variable damper was used in conjunction with the secondary sinusoidal base excitation to reduce the response due to the primary base excitation. When the primary sinusoidal base excitation contains the natural frequency of the system, the resonance is induced. However, another resonance can be generated by the modulated component caused by the variable damping device and the secondary base excitation. The additional resonance was adjusted to be out of phase with the primary response, and the response of the structure was effectively reduced as a result of the damping. However, no such study considering the multi-degree-of-freedom system has been conducted. This paper presents the effect of the harmonically varying damping on the multi-degree-of-freedom system, especially; the influence on two structures in parallel with a variable damper between them is discussed. In addition, the new filter is also demonstrated in this study. The new proposed semi-active control laws require the phases of the structure's vibrations. However, obtaining the phases of the vibrations would be difficult if the vibrations were complex. Therefore, the new filter using a nonlinear oscillator, Stuart-Landau equation, is proposed. The filter is taken advantage of the synchronization properties of the nonlinear oscillator, and the output of the oscillator has the characteristic frequency designated by the oscillator. The validity of the proposed system is shown by numerical simulation.

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In late years, large scale earthquakes are occurring in the world. Then, control of seismic response of house is important for protection from destructive earthquakes. This paper proposes some types of oil dampers for vibration control device for two story houses. Oil damper is connected to the ceiling of the first story and fixed on the foundation. The rectangular parallelepiped damper, the cylindrical damper and the spherical damper with silicon oil are proposed. The effectiveness of oil dampers is examined by experiment and simulation. It is concluded that the peaks of the resonance curve are reduced when dampers are used.

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In recent years, because of demand for rebuilt the building that were constructed in high economic growth period (1960s), demolition work is carried out energetically in many places in Japan. Heavy equipment such as excavators is commonly used to the demolition work. However, the excavators generate uncomfortable vibration to neighbors. Therefore, the purpose of this study is research and development of vibration control device for excavators. A Tuned Mass Damper (TMD) is most commonly used for vibration control. Usually the TMD is tuned by using optimal design formula depending on the weight and the stiffness of the control target. However the tuning violated if the parameters of the control target are changes. In order to solve this problem, a Multiple Tuned Mass Damper (MTMD) is proposed in this study. The MTMD consists of a primary mass and secondary mass. The secondary mass is placed on the primary mass in series. Applying the secondary mass can widen the effective target frequency range of vibration control. In this paper, compared the performance of MTMD and TMD in numerical simulation. Then, prototype MTMD was fabricated and its performance was verified experimentally. As a result, it is confirmed that the prototype MTMD has effect in vibration control for excavator.

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Japan is a land of earthquakes. The great east Japan earthquake occurred on March 11, 2011. This was immense damage. Particularly, many high rise structures in which were a long distance from the hypocenter of the earthquake resonated with the long period ground motion. Long period ground motion has a predominant period of from a few seconds to ten seconds and a duration time is more than a few minutes. Industrial plants, there are boiler plants as a long period structure, and they are in danger of resonating by long period ground motion. Recently many industrial plants require countermeasure for long period ground motion. Various viscous dampers have been proposed and applied to actual structures to suppress vibration response. However the vibration control performance decreases with the long duration time, because of a temperature rise of the viscous material. Therefore there is concern that these viscous dampers can not suppress vibration response in case of the long period ground motion. In order to solve this problem, the authors propose a viscous-friction damper in series. In this hybrid damper, the friction damper can absorb vibration energy as well in case of the long period ground motion. In this paper, we conducted seismic response analysis of the hybrid damper which was installed a boiler plant.

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When an elevator rope for a high-rise building is forcibly excited by long-period ground motion, rope displacement becomes large even if the ground acceleration is small. Therefore, detecting the rope sway in real time is important to avoid damage during and after earthquakes. In a previous paper, when elevator cage is moving, a simplified calculation method, based on a single degree of freedom (SDOF) system, for estimating rope displacement during an earthquake by using the building acceleration and ground acceleration is presented. This simplified calculation method is applied to main rope, which resonates only one time with building's sway while the elevator is moving. In the case of the main rope, the results of this simplified calculation method agree with those of the conventional finite difference method (FDM), within the 20% error margin. In this paper, the simplified calculation method is applied to compensating rope, which resonates two times with building's sway while the elevator is moving, by considering the rope tension. Finite difference analyses of rope vibration are also performed to verify the validity of the simplified method. The results of this simplified calculation method agree with those of the conventional finite difference method, within the 30% error margin.

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The final purpose of this paper is to estimate the efficiency of some stochastic floor response spectra in order to easily estimate the dynamic characteristics of secondary system such as piping, equipment and so on, mounted on a structure owing to an earthquake. Because of the increase of uncertainty at earthquake level, the design level for earthquake is tending upward. This is implying that the aseismic design of secondary system based on elastic design becomes more difficult from the viewpoint of economic design. Thus, as a first step, one paper by author has been derived as for the stochastic floor response spectra in consideration of a simple nonlinear design. As a second step, the multi supported secondary system is testified in consideration of correlation between multi components of input. The nonlinear properties of the secondary system are modeled in terms of an equation of motion which linearly involves the auxiliary variable as part of the restoring force and the auxiliary equation which describes a nonlinear relationship. Total equations including the auxiliary equation are linearized using a stochastic linearization technique. Then executing the statistical calculation to obtain the non-stationary variance relating to relative displacement of secondary system, finally the stochastic dynamic characteristics of the multi-supported nonlinear system can be derived analytically. The obtained results are compared with those by Monte Carlo simulation.

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In this paper, we propose the seismic response analysis method and investigate the optimal design of the piping system supported by elasto-plastic damper subjected to the random input based on the random vibration theory. The piping system is modeled by simple cantilever beam with weight. The support force is given by bilinear model. The inputs are given by white Gaussian noises. In this optimal design, we can maintain the structural integrities of both the piping systems and the elasto-plastic supporting devices by taking three indexes; dynamic reliability of pipings, accumulated energy of support and dynamic reliability of support into account. Furthermore, the optimal conditions of parameters such as the supporting location, the capacity of the supporting devices are searched. Numerical simulations are performed using a simple piping system model for the random input based on the probabilistic vibration theory. The optimal design proposed here is applicable to the seismic design of piping systems supported by elasto-plastic dampers subjected to the actual earthquake input.

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Generally, mechanical structures are required to be highly safe to withstand a lot of earthquakes. Therefore, seismic evaluation and design techniques that are able to evaluate cumulative damages have been required. According to studies on failure of pipes, the load due to earthquake is a cyclic loading. The relationship between failure and the energy is evaluated, examined by paying attention to the Energy Balance Method said to be effective as an earthquake response analysis technique in the present. Moreover the Energy Balance Method has aimed at the generalization of the earthquake-proof evaluation technique. This study carries out failure experiments using simple single degree of freedom models having various cross sections. Although the object dealt with by this research until now is a simple single degree of freedom model of hundreds of gram order, in order to perform detailed earthquake-proof evaluation for an actual mechanical structures, examination by the large mass type model near a real structure is needed. The consideration of the influence of the section modulus or the moment of inertia area on the energy required to failure is examined as a parameter of the shape of cross section by using the model of tens of kg order, by focusing on the microscopic response for the strain of point of failure.

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With a recent size and weight reduction of electrical transformers, acoustic noise from transformers is likely to increase in a zone of audibility. Underlying technology for the acoustic noise reduction is required. Electrical transformers consist of iron cores, coils, tanks, frames and other structures. These vibration mechanisms and propagation path are unexplained clearly as a sound source. Investigation for each vibration characteristic is required to reduce the acoustic noise. In particular, as a sound source of electrical transformers, Understanding characteristics of an iron core are important. Experimental Modal Analysis (EMA) for a laminated iron core is performed with an impact hammer. EMA gives us the natural frequencies and vibration modes to reduce acoustic noise. Also we investigate a reliability of the Finite Element Method (FEM) models.

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Due to increase of capacity and weight saving, bigger electrostatic and magnetic energy is stored in transformer, compared with conventional transformer. Because of these, Vibration and noise are likely produced. In the field of noise reduction of transformer, core vibration by magnetic-striction, winding vibration and sound proof of transformer and tank have been studied. Winding vibration due to the currents produce sound wave in the insulation oil. This wave spreads in the oil and vibrates tank of transformer. The transformer tank yields a fluid elastic vibration hitherto, two-dimensional fluid is analyzed by FEM with dis placement method. However, the fluid-structural analysis of a coil and a tank of transformer have not been studied by a three-dimensional FEM. In this paper, the method of calculating the character frequency which took the influence of oil into consideration from the fluid-structural analysis by three-dimensional FEM which is not in the former with sufficient accuracy was found out. Since it showed clearly that it changes with modes of vibration, the decreasing rate of character frequency and oscillating attenuation by oil are reported.

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The purpose of this study is to clarify the characteristic of vibration of the transformer coil, and to predict electromagnetism vibration of the transformer coil. Therefore, the exact Finite Element Method (FEM) model of transformer coil is required. In this research, the modeling of the transformer coil vibration of the axis direction and the diameter direction was carried out. The modeling of the transformer coil was performed with the equivalent parameter. The equivalent parameter calculated based on the Experimental Modal Analysis (EMA) result. The characteristic value analysis error is 10% or less. The result of the frequency response analysis of the FEM model was good agreement with the experimental result.

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The effects of gear intermeshing condition, such as load torque, mesh angle, and distance of gears, on the gear noise has been studied experimentally. Though the gear noise problems have been investigated by a lot of previous researchers, the gear noise is still one of serious problems in motorcycle business. It is widely known that gear noise is greatly affected by intermeshing condition, but the relation between them has not revealed clearly. The purpose of this study is to make clear the effect of intermeshing condition on gear noise. To find this, we measured the sound pressure due to a pair of gears changing several parameters. As a result, several higher frequency response of tooth mesh frequency were observed, and spectrum level of these frequencies might be changed by the lord torque, mesh angle or distance of gears. It may be possible to estimate the intermeshing condition by measuring the gear noise and comparing the noise level of higher frequency response.

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Acoustic Radiosity is a method based on an assumption of diffuse reflection and incoherent phase relationships that has been used to predict room sound fields. The sound field analysis of high frequency can be calculated in a short calculation time when this technique is used. In this research, the sound power level in the opening of a box which has a sound source in it is calculated by using the Acoustic Radiosity Method. Results were compared with experimental data and calculation results of Boundary Element Method (BEM). The sound power level on opening was calculated under conditions with and without partition board and noise absorbing material. As a result, it was verified that the result of the sound power on opening was calculated accurately by using Acoustic Radiosity when the field space was greater than the wavelength in spite of the fact that the calculation time was much less than that of BEM.

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This paper discusses the vibration transmission of the violin structure for deriving the knowledge to reduce the machinery vibration and sound. We focus on the violin-bridge and the sound-post structure. The violin-bridge structure introduce the transmission to the infinite structure and has the power input proportional to the root of frequency. In this paper, the simple plate-bridge structures are used to identify the vibration to the infinite system. As a result, it is shown that the separation of the bridge and the panel is important. The sound-post structure brings to transfer the vibration to the particular part of object machinery effectively. In order to design the position of the sound-post to be set, we discuss the relation between the vibration energy model (SEA model) and the natural modes by using the test structure with two beams connected by just one bar is used to discuss. It is concluded that the relation is very simple in case that the SEA equation is satisfied and it is difficult to discuss the relation in another case.

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There are some types of sound localization methods which are used for noise source identification of prototype products in machine development. In this paper, the experiments of noise localization are done to analyze the linear noise slider mechanism which make a transient noise. As a noise source localization method, the Near field Acoustic Holography(NAH) was used. Some experiments showed that the motor vibration of linear slider cause resonance in the inside of linear slider. After that, we tried to reduce the noise level.

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In recent years, the study of sound source localization in order to suppress the noise becoming actively. But, sound source localization that intended for impact sound has not been performed because the theory of sound source localization has been postulated steady sound. In this paper, we proposed a procedure for sound source localization analysis of impact sound, and compared with the conventional method by experiment. We are evaluating whether to achieve better results for the transient sound source by using the theory that is based on a Near-field Acoustical Holography (NAH), changing the continuous wavelet transform rather than Fourier transform. The results of this study, we observed that expression for the transient sound becomes more appropriate by the NAH after processing with continuous wavelet transform.

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A numerical method is proposed to calculate response analysis for automotive sound proof structure including elastic body, viscoelastic body and porous body using three dimensional FEM and MSKE method. Displacement vectors as common unknown variable under coupled condition. The explicit expressions of modal loss factors for the sound proof structures are derived using Modal Strain and Kinetic Energy Method (MSKE method) proposed by authors in our previous paper. Using this technique, eigenvalue analysis and frequency response analysis are performed for the automotive sound proof structure. In this report, we deal with a porous material sandwiched between a steel cover plate and a base plate (steel plate with a viscoelastic damping layer). We investigate vibration transmission characteristics from the base plate to the cover plate. Especially, we focus on the influences of curvature of the base plate on the vibration transmission. We set the curved plate as a convex upward structure, while the cover plate is leveled. Thus, the distance between the base plate and the cover plate become short locally because of the curvature. This caused sound bridge phenomena.

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Parametric array loudspeaker (PAL) produces a highly directional sound beam due to the attribute of ultrasound used for carrier waves. Active noise control system with PAL has merit because it less causes spillover than that with normal loudspeaker. However, PAL still have serious problem in its sound quality because of harmonics. To solve this demerit, this paper propose a method using a adaptive filter to decrease harmonics sound pressure. In spite of simple process, we obtained good results by three cases experiment. These experimental date show this system is superior to conventional method such as Single-Sideband modulation (SSB) from two points of view. First, this system can control sound pressure both of the 2nd harmonics and intermodulation distortion. Second, the control effect is obtained on wide area with only a microphone.

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Self-excited sound caused by flow is observed in the vehicle cabin, when the vehicle runs with an open window. This phenomenon is called wind-throb. In this study, we measure the sound pressure in the vehicle cabin and explore the possibility of suppression of self-excited sound generated by Fluid Resonant Oscillation. We tried to prevention of wind-throb by using of a baffle plate. A baffle plate is set inside of the cabin. Accordingly, in this study the baffle plate prevents from occurring wind-throb.

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The objective of this paper is to derive explicitly the eigenpairs of the coupled cavity comprising five rigid walls and one flexible panel. First, the coupling orthogonality conditions the eigenpairs need to satisfy are derived. Using the coupling orthogonality conditions, the modal equation of the coupled cavity system is then obtained, permitting one to deal with a forced response of the coupled cavity. It is shown that the eigenfunctions governing the dynamics of both the sound and the vibration fields are expressed as the infinite sum of cluster eigenfunctions. The characteristic matrix equation is then derived, specifying the eigenpairs of the coupled cavity. In order to investigate the fundamental properties of the eigenpairs derived, a numerical analysis is conducted, revealing the presence of evanescent modes in addition to the conventional standing wave modes.

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This paper describes vibration analysis using fast finite element method for an automotive sound proof structure with body frames supported by nonlinear concentrated springs. The sound proof structure is constituted of a porous material sandwiched between a steel panel and a cover plate. And we use three-dimensional finite elements and Modal Strain and Kinetic Method to express the damped dynamic motions of the structure. Restoring forces of the nonlinear springs have cubic nonlinearity. The discretized equations for the global system in physical coordinate are transformed into the nonlinear ordinary coupled equations using normal coordinate corresponding to linear natural modes. This transformation yields computation efficiency. The structure is excited periodically. We computed nonlinear stationary and non-stationary responses due to internal resonance in coupling modes between the nonlinear springs and the sound proof structure under large input. The non-stationary motions are confirmed as the chaos due to maximum Lyapunov exponents with a positive number. From the time histories of deformation distribution in the chaotic vibration, we found out nonlinear modal couplings.

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This paper describes the new method of acoustic resonance reduction using a plate, a piezoelectric element, and an LR circuit. The acoustic resonance generated in an enclosed space induces the resonance of the plate. Further, the resonance of the plate induces the electrical resonance between the inductance and capacitance in the piezoelectric element. The electrical resonance equivalently gives damping effect to the plate, and the vibration of the plate suppresses the acoustic resonance in the relatively broad frequency range. The governing equations were theoretically derived, and the optimum values of the plate and electrical system were approximately formulated on the basis of the two fixed points method. The formulations and effectiveness of the proposed method were verified through simulations and experiments.

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Designing a kind of noise insulation Polycarbonate pane is an important object to provide the maximum comfort during driving in Automobile. This paper investigates noise transmitted into rectangular cavity through polycarbonate pane. This transmission phenomenon is a typical fluid-structure interaction problem. The coupling analysis of cavity-pane system is modeled by combining the modes of simply supported pane and cavity modes. The numerical results reveals that noise attenuation can be realized by appropriate selection of structural parameters such as the damping of structural and cavity, the thickness of the pane, and density of viscoelastic core material.

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Higher-order mode sound waves in an infinite rectangular straight duct can be attenuated using a thin flat plate parallel to the duct axis inserted in the duct. The performance of the plate has been confirmed experimentally by the authors for the (1, 0) mode sound wave in the duct. The property of the plate varies according to the length and position of the plate. In this study, the sound field in the duct is numerically calculated using the boundary element method (BEM) for revealing how the plate affects the sound. After the analytical model for BEM appropriately representing the (1, 0) mode wave propagation in the duct is constructed, the reliability of the calculation is confirmed by comparing the calculated results to the measured ones showing the amount of sound reduction by the plate. Then the mechanism of sound attenuation is considered by studying the calculated sound fields (sound pressure distributions) in the duct. The frequency of the sound reduction seems to depend on the relation between the plate length and the axial wavelength of the (1, 0) mode in the area where the plate is inserted.

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This study aims to be improved classical guitar's sound quality. We are studying for an adjustment in the guitar's volume, power and expression. In particular, we noted surface plate, because the plate affects greatly sound quality. In previous study, we forwarded to design best structure. The plate stretches bracing on the reverse plate. We searched the best layout, and designed good idea. However, there are some problems in these prototypes. Surely, the envelope became gentle slope then the guitar sound was more high quality. The low tone sounds good, though the high tone sounds little harsh. This target is to control, and to amend high tone sound from sharp to soft. Hence we put the magnet near the bridge; moreover we analyzed new model vibration and frequency characteristic. As a result, we decided the good position. It should put near the 1, 2, 3 strings and near the sound hall. When we put there, the guitar became soft sound. Therefore we can control the classical guitar's high order ingredient.

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Since a visual navigation system using smart-phones show information on small screens, users distracted attention is likely to be distracted. So, we are considering a portable navigation system by using Audio Augmented Realty. However, if such equipment is used outdoors, very loud wind noise is recorded with environmental sound. Therefore, to reduce wind noise, we use wind screen and applied signal processing for wind noise reduction. In this paper, we investigated improvements of the subjectivity speech intelligibility. It was shown that iterative Wiener filter improves a speech intelligibility score dramatically.

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This paper describes a product quality check of micro fan vibration by using the fluctuation mechanism. The micro fans are used by many electronics equipment for cooling. It is essential for present industry. But, the micro fan has checked by surveyor who has experience skills which using their auditory organs and tactual sense. It is not easy that surveyor masters their skills, and large errors are produced by their mental and physical condition when they survey. Now, new evaluation and diagnosis method is needed. This study focuses to moving of surveyor's hands, and uses fluctuation mechanism and inclining angle change mechanism. The experiment measured the acceleration of micro fan's vibration, and took the deviation between the acceleration overall maximum level and minimum. These results show one of methods that make sure of the diagnosis of micro fan's vibration.

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In the development of measures against railway wayside noise, vibratory characters of rail has been important factor. The characters of rail in operational railway lines are similar to those of infinite beam. On the other hand, the characters of shorter rail, which is applied at laboratory test, corresponds to those of finite beam, due to the reflection of vibrational wave at the rail end. Therefore, the reflection of vibrational wave should be reduced while evaluating the performance of the measures for operational railway lines by shorter rail. In this paper, the effect of tapering the end of shorter rail (10m) has been investigated. Additionally, the evaluation of the measures has been conducted both at laboratory and operational line.

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This study investigates the effect of aging on the evaluation of the optimum diameter during pipe easiness to grasp by the rating scale method and the paired comparison method. The pipe diameters examined from 25mm to 50mm. The mean value of the optimum grasping diameter evaluated by college students was lager than that evaluated by elderly persons. The rank between maximum and minimum evaluate value (range) in the college student was higher than that in the elderly person. These characteristics were depends on the abundance of the image appeared at grasping and the sensitivity of the cutaneous sense of hand.

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The study investigates the effect of the division ranks of the sensory evaluation scale on the evaluation of grasping of cylindrical object. The evaluation tests were performed using the division ranks of 2-7 and the paired comparison method. The optimum diameter for grasping pipe evaluated by the sensory evaluation method with using several division ranks of answer were almost agree with that the paired comparison method. Furthermore, the optimum grasping diameter evaluate were decreased with increasing the number of division rank and up to 4 ranks. Therefore, the 4 or more division ranks of answer was high accuracy of the sensory evaluation than the 2 or the 3 division answer.

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In this study, the easiness of operation of wheelchair evaluated while the handle grip position changed. The easiness of operating of wheelchair was movement in daily living activity. The experiment movements were direction conversion, rotation, u-turn, meandering, beyond bump, climb and down. The sensory evaluation data obtained from the SD scale during wheelchair movement were analyzed by the factor analysis. The cart type wheelchair installed in the position 54% of height got a good evaluation subjectively and physically i.e., easy to operation and low physical load.

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This research is research on the method of compressing a mat sensor which detects motion of sleep. A data compression is immediately performed by sensor CPU. Moreover prolonged measurement needs to save energy. Therefore Were studied at the threshold of compression methods, we propose a new compression method and the general RMS

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In recent years, the healing music of low and middle frequency sound is very popular among every generation. While, it is told that the highest quality sound such as Stradivarius violin includes smooth harmonic sound over 20kHz which is not audible but is one of the reason for the beautiful sound. Therefore, the healing effect of high note sound such as trumpet and cymbal are newly tested by the electroencephalogram (hereafter EEG) of a simplified brain waves device when audiences are listening to a Super Audio CD (hereafter SACD) and an actual musical instrument. As a result, the high note and high quality sound not only generates alpha wave but beta wave, which means that the high quality sound is affected to the brain waves and is well balanced with hearing and exciting effects. In the near future, this analysis method using EEG and sensory evaluation will be reflected to the further improvement of cymbal sound quality.

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In painting world, repair of house wall is carried out by hearing user's taste. However, sometimes the mismatch trouble has happened. For solving this kind of trouble, color simulation software for house repainting was developed. In this paper, brain wave of users who see the screen of color simulation will be measured. And, their mind condition will be examined by referring to brain wave α and β.

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Japan is currently rapidly aging. Concurrently, the number of patients suffering speech disorders is increasing every year, and the incidence is higher as age increases. Those suffering from speech disorders face problems with communicating in daily conversation. They are often able to communicate with speech substitutes, but these typically do not provide a sufficient sound frequency range to be understood in conversation. Therefore, we proposed a speech support system using body-conducted speech recognition. This system retrieves speech from body-conducted sound via a transfer function, using recognition to select a sub-word sequence and its duration. In this study, we demonstrate the effectiveness of producing clear body-conducted speech using a linear predictive coefficient instead of a transfer function. Instead of dividing body-conducted speech into syllables in a heuristic manner as in past studies, we used continuous sub-word recognition automatically. To confirm the improvement in generated speech, a jury test and articulatory feature analysis were employed.

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Since communication is essential to all people, speech disorders cause great distress. In this study, we proposed a speech support system for articulation disorders, resulting from dysfunctions of the articulatory organ that make it difficult for the individual to vocalize accurately. We adapt the method used in a previously developed speech support system to articulation disorders. In our previous studies, we focused on phonation disorders caused by the loss of vocal cords through pharyngeal cancer. However, since the difference between articulation and phonation disorders is merely the position of the impairment, the proposed system could also be applied to articulation disorders. This is accomplished by incorporating the LPC (linear predictive coefficient) of articulation estimated from a healthy person into the BCS (body-conducted speech) of the individual with the disorder. For ease of use in daily life, we have implemented this system using portable devices like smart phones. In this study, we focused on two aspects. First, we confirmed the validity of this system for articulation disorders. Concretely, we made the BCS clearer using LPC, and evaluated the articulation quality using discrete word recognition. Second, we investigated the effect of speaker adaptation to the articulated speech. In order to implement our system on portable devices to facilitate practical use, we conducted recognition using speaker adaptation for the articulated speech. This resulted in a highly improved recognition rate. Therefore, we confirmed that our system is applicable to articulation disorders, and has acceptable recognition precision using speaker adaptation.

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In this paper, we examined the actuator finger is bent enough to focus on the rehabilitation of the finger support. It is difficult to support finger joint motion with existing actuator. In this study, we performed a study of actuator bending the joints of all fingers of an air pressure as a power source there. We have proposed to the conventional ones proposed structure can change the place bent in the same actuator, make it an increase in torque at the same time, create a prototype, to bend the finger.

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A stand alone wearable power assist suit we developed gives nurses the extra muscle they need to lift their patients and avoid back injuries. The suit consists of shoulders, arms, back, waist, hip and legs units to be fitted on the nurse's body. The arms, waist, hip and legs have newly developed rotary actuators consisting of air bags driven directly by micro air pumps supplied by portable batteries. But air bags can produce the force only at the expansion, so a linkwork is needed to waist and hip joints, and the linkwork projects into the back. For realizing the suit available in the narrow working space, air cylinders should be adopted, but it needs a high pressure air compressor. Therefore, it cannot become wearable suit, but can become practical as a power assist suit in the construction site and the factory equipped with an air pressure supply line. This paper reports the development status of a power assist suit utilizing air cylinder.

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Many hemiplegias use ankle-foot orthosis to prevent foot drop when they walk. However, it is difficult to walk smoothly because a conventional ankle-foot orthosis has high rigidity. In order to support natural gait of hemiplegias, in this study, a technique to regenerate energy is applied, and a new self-powered semi-active ankle-foot orthosis including a DC motor and step-up chopper circuit is developed. In this method, safety long-time continuous drive that is not restricted in time and the place is enabled and damping at ankle joint can be controlled. With developed ankle-foot orthosis, relation between angular velocity and braking moment at each duty ratio are derived. It is in this way shown that changing electric current of the circuit change damping force of developed ankle-foot orthosis. In addition, by experiment on the consecutive walk, it is shown that developed ankle-foot orthosis can control damping at ankle joint, charge battery by regenerating energy loss during a gait and prevent foot drop, and it is expected that developed ankle-foot orthosis provide higher effect than conventional type in ability to improve hemiplegic gait. Furthermore, as a result of estimate with measured electric current, developed ankle-foot orthosis shows high electricity recovery (86.5%).

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A vehicle driven by electric motors has been expected to find uses as personal mobility vehicles. We have been developing an electric skateboard as a candidate of personal mobility vehicles in the future. It is necessary to control the center of gravity of a driver on the board for being a comfortable transportation. The control design requires knowledge of human body dynamics on lateral motion. As a first step, we developed an electric skateboard with load measuring devices and tried to clarify the mechanism of human body dynamics by impulse response. To analyze the human body dynamics precisely, we applied a velocity servo control instead of acceleration control. Comparing with previous studies, the electric skateboard can apply large external force to the subject. We assumed a model based on hip strategy which keeps upper trunk perpendicular to the horizon consequently. As a result, feedback parameters of posture control on free standing delay time could be derived.

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The purpose of this study was to formulate a methodology to evaluate dynamical functional roles of upper joint torques during golf swing motion in considering deformation of club shaft. The upper limb segments and grip handle part of golf club were modeled as a system of seven-rigid linked segments, and constraint axes of the elbow and wrist joints were modeled with constraint equation in order to consider the anatomical degree of freedom of the joint. The deformation of club shaft was modeled as angular displacements of virtual joint settled between adjacent segments by dividing club shaft into rigid segments. The angular displacements were defined as roll-pitch-yaw angles, and joint torques at each virtual joint were calculated by assuming rotational spring and damper about each axis of the virtual joints. A recurrent equation with respect to the expanded generalized velocity vector, which consists of generalized velocity vector and the time integration of the velocity vector, is derived to calculate the contribution of the joint torque terms, external joint force term, and gravity term to the generation of the expanded generalized velocity vector.

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This paper describes a vibration analysis system for the examination of the vibration transmitted from the road to the human body when riding a bicycle with two infant seats, we designed a vibration model for a bicycle-driver-two infants system and calculated the vertical vibration at transient response. To examine the feasibility of the vibration analysis system, the vertical vibration of the analytical results were compared with one of measurement results. The relationship between the mechanical properties of two infant seats and the transient response of the human body were examined. From these results, the analytical results corresponded with the measurement results in the head and torso of the driver and the infants. It was clarified that the mechanical properties of two infant seats influenced the infants and the lower arm of the driver.

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With our society rapidly aging, it is worried that the burden on families who have members in need of nursing care increase. The elderly people sometimes have come to require nursing care caused by falling. To reduce the risk of fallings in elderly, gait measurement is conducted as community health. With the conventional gait measurement system using force plate or 3-dimensional motion measuring device, it has been difficult to introduce in community health activities because of its scale and cost. Therefore, it is necessary for gait measurement system that applies in every place and low cost. In this study, a gait measurement system using laser range finder (LRF) is proposed. In the proposed system, legs of the subject are detected by the range data of LRF. Then, the system obtains the human motions in the horizontal plane and extracts the particular kinematic parameters during walking. To verify the availability of the extracted parameters, the proposed system was applied to the walking test. Test subjects walk stepping on the predesignated targets in the walking test. By applying to the test stepped correct target and extracting particular kinematic parameters, the availability of the proposed system was verified.

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We developed real-time living activity measurement system that monitored heart beat information and the bodily movement from a photoplethysmography and a acceleration sensor. The outside optical noise reduction technique was performed by the pulse luminescence of LED and high-pass filter proccess. Discerning the basic motion running, walking, and working, etc. became possible by from 3-axes acceleration sensor output.

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In order to implement an unobstructed assessment of three-dimensional (3D) gait, we developed a mobile force plate and three-dimensional motion analysis system (M3D) to measure triaxial ground reaction forces (GRF) and three-dimensional orientations of feet. Calibration and test experiments were conducted to characterize the developed sensor. To test accuracy of the new measurement system, validation experiments by using reference measurements of a commercially available measurement system were performed in a gait laboratory, where a stationary force plate, a motion capture system based on high-speed cameras and a motion track system of XSENS are adopted to analyze human movements. Experiment results supported that the developed system can be used to measure triaxial GRF and orientations with an acceptable precision during successive walking gait.

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We developed a device that calculates and displays the center of gravity point and joint moments at the same time with motion. By using this device, stability and physical burdens can be checked with movements. Then dynamic consideration and understanding about the burden outbreaks are obtained. This research paper represents the most suitable method of lift-up motion with a little physical burden. In lifting up a baggage, your physical burden is caused by the gravity and inertia on your body and the baggage. And we offer that you should close in the baggage with your upper body upright and rise to your feet a little before lifting up. This lift-up motion can reduce both of static and dynamic waist moment and knee moment. In the application of this Real-Time Analyzer to analyze lift-up motion, we examined that closing in the baggage with your upper body upright before lifting up is allow of reducing both of static and dynamic waist moment in lifting up and prevent injuries of your waist joint and knee joint.

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We have developed an electrostatic three-axis MEMS accelerometer with single-mass and vertical comb electrodes. In this paper, we measured the cross-axis sensitivity using three-axis vibration stage based on sensitivity matrix concept. The main axis sensitivities of x, y, and z-axis are 738, 743, and 238mV/g, respectively, which are slightly lower than simulation. The cross-axis sensitivities are 0.4-15.6% of main axis sensitivities, which is larger than the simulated value. The reasons are estimated to be the misalignment of the sensor to the vibration stage and unexpected rotational motion of the three-degree of freedom shaker.

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The calibration method based on a vector space theory has been proposed for multi-axis accelerometers. In this method, acceleration generated from a 3-DOF vibration table and the output signal from calibration target accelerometers are treated as vector quantities and a calibration result is described as a matrix. This method has many advantages of short measurement time and cross sensitivity evaluation. In order to realize more efficient measurement, a simultaneous calibration technique is required. However, it is supposed that uncontrolled rotational motion of a 3-DOF vibration table generates position dependency on some of the elements of sensitivity matrix. This paper reports the effect of rotational motion on the vibration table in the sensitivity matrix calibration of an SOI capacitive 3-axis accelerometer. In order to clarify the rotation effect on sensitivity, we made a 6-DOF reference sensor in combination of 3 single axis accelerometers and 3 single axis gyros As a result, certain elements of the cross sensitivity show the position dependency at a 150Hz excitation, which could be near the resonant frequency of rotation. This result is explicable by approximate expression of sensitivity calculation.

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