Due to the interference between two sets of repetitive gratings Moire fringes are generated. These patterns are also used in metrology for the measurements of surface profilometry, 3D surface reconstruction and so on. Recently it is approached as an emerging tool in the fields of biomedical engineering fields - particularly in biomechanics and bio-sensing. Conventional Moire interferometry evaluates the interference of two light waves being reflected on a reference surface and the object to be profiled. However, difficulties in satisfying the requirements for the current significant issues in obtaining accurate dimensional information as well as dimensional deformation are dealing with micro-level and nano-level in an on-line inspection environment. Particularly, in the present real-time biomedical inspection of auto-inspection and auto-operation of inner organs of human body needs precise information of inner movements. In that case single light wave system makes the Moire sensing system easier and applicable in real-time imaging. However, modeling the sensing system based on CCD parameters of the camera and its application in capturing of Moire images make the systems challenging as well.

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It is extremely important to estimate the spatial location of sound source under various vibrations and noise phenomena. With this background, techniques for estimating the location of sound source as non-contact testing are widely used for understanding various vibrations and noise problems intuitively. In this study, our goal is to estimate spatial location of sound source by the combined method of MUSIC algorithm as well as Spatial Smoothing Processing (SSP) and Scanning Technique. In particular, the handy microphone array system for evaluating the performance of combined method was developed. This paper presents both the analysis method and performance of combined method, and demonstrates the performance tests for estimating the spatial sound source location. As a result, it is possible to estimate the spatial sound source location with high accuracy applying the combined method through a series of experimental and computational examinations.

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It is important to know the tension of wire rope in use to avoid accident. But most of wire ropes are being used without knowing their tension. So far many ideas have been proposed to evaluate wire rope tension in use. However, few ideas have been realized to the present. We developed a simple wire rope tension meter that could be attached to a wire rope easily in use. The device applies twisting torque to a part of the wire rope by a stepping motor. A linear relation between wire rope tension and the torque obtained by the device was confirmed by the experiments. In addition, the change of wire rope tension and twisting torque with time were evaluated. They decreased gradually with time. Therefore a decrement of wire rope tension is able to be estimated by twisting torque. A simple model was proposed to account for a linear relation between the wire rope tension and twisting torque and hysteresis ioop associated with twist loading on a rope. From these experimental studies, the device seems to be effective for evaluation of wire rope tension.

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The primary industries that is the basis of the industry of Japan, especially the fishery industry is received the fatal damage from the disaster due to and giant Tunami induced by the Great East Japan Earthquake, and still exists in the process of the revival. Big power of nature influences the primary industries that deal with nature. Moreover, the fishery industry is in a severe financial health by the sudden rise of the fuel oil though shoulders an important role to supply people's protein sources. The Ministry of Agriculture, Forestry and Fisheries is that calls the sixth industry from the primary to the tertiary industries, and attaches importance based on so. The development of an environmental-friendly alternate fuel is hoped for because carbon dioxide that is one of the invitations of global warming after it burns is exhausted though the fossil fuel such as oil is used for the fuel of the engine for the fishing boat. In the laboratory, the fishing boat remade to the engine that makes hydrogen a fuel from an existing fossil fuel is developed so that the fishery person who has become poor managing it may also use environmental-friendly and the renewable energy fishing boat by the low cost as much as possible. When it is a research to use "Hydrogen" for the fuel for the fishing boat from a mid/long-term aspect, this research will soon locate alternate fuel such as the bio-alcohol and BDF(Bio Diesel Fuel). In this paper, the annulment of plan in the miss fired the hydrogen engine, for examples, induced by an electric devices and spark plug or the power increasing an idea of the hydrogen engine are described.

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This paper concerns a machine health monitoring of vibration cutting system which is one of the precision machining technology for cutting modern aviation materials or hard metals. The vibration cutting is conducted with ultrasonic vibration superimposed on the cutting tool movement. The major objective of this paper is the experimental investigation of vibration signatures to occur for the cutting speed increase or localized wear/damage on the tool edge. Our experiments show that the higher frequency vibration than the natural frequency occurs before the machining state turns worse. We hope that abnormal machining detection is possible using FFT analysis.

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Milling is one of the most important metal cutting processes. If we can measure the cutting force of milling process in real time, we will be able to make cutting process optimum, prevent tool breakage. But especially when we use an end mill with small diameter, it is very difficult to measure the cutting force in real time because of its small cutting force. In this paper, we developed a tool holder with torque sensing function in it by using a magnet coupling with magnetoresistance sensors. Especially, we developed the technique which can compensate error by using analog circuit. Thus we confinned that it can improve an accuracy of torque measurement.

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This paper introduces motor current signature analysis method (MCSA) for machine diagnosis. MCSA method was mainly applied for electrical failure diagnosis. Also for mechanical failure diagnosis, vibration analysis method was mainly applied. We applied motor current modeling method and auto studying methodology to motor current analysis to improve failure detecting capabilities. Finally, we success to detect not only electrical failure but also mechanical failure in practical accuracy.

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[in Japanese]

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This paper established a condition monitoring and diagnosis method of motor and rotating machine which be driven by the motor by analyzing the driving current signal of three aspect induction motors multiply, and systematized the method. With the method that abnormal states such as broken rotor bar, rotor eccentricity, slot fault, mechanical unbalance, mechanical misalignment, bearing fault, fluid abnormal, electric abnormal, etc. can be distinguished. And moreover TAKADA-Motor Current Multiplex Analysis and diagnosis system T-MCMA was developed based on the proposed method. Due to current signal can be measured in an electric indoor electric board, so not to mention general rotating machines, this system is most suitable for state monitoring and diagnosis of machines which be installed in a liquid, and the high temperature environment, the high humidity environment or be installed in poison, dynamite, the radiation area.

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The fault diagnosis by vibration signals on rotary machineries is more difficult than independent mechanical elements, because almost complex machines are composed of great number of structural bodies and mechanical elements. Rotary machineries find it hard to identifi of fault elements to exist a number of noise sources within the engine. This paper proposes a new condition monitoring method on rotary machineries by multiplex elements Auto Regressive model and cross correlation of close two point signals generated by diagnosed machines. Artificially assumed fault conditions in rotary machineries are concerning a rotor and gear unbalance, a wear of gear. Identification of above the fault conditions has been carried out based on the proposed method at diagnosed location within the rotary machine. It is possible to diagnose above fault condition by the proposal SN ratio improvement method.

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The purpose of this study is to establish a measurement method to get vibration characteristics of membrane structures. An impulse hammer or a vibration exciter has been used to measure the vibration response of constructions and mechanical systems, but this method is not appropriate to apply the impulse force for the membrane structures due to its lightness and flexibility. Consequently, non-contact impulse excitation is applied by using laser excitation system and is suitable for the vibration measurement of the membrane structures. The proposed method makes the precise measurement of the frequency response in wide frequency range possible. In this study, mode shapes of the membrane structure are investigated by the vibration testing system using the non-contact laser excitation and the non-contact vibration measurement with LDV.

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Bolted joints are widely used in mechanical and architectural structures. However, many serious accidents occur because of loosening in bolted joints. The diagnosis of the bolt loosening is able to be achieved by evaluating the variation of tightening axial tension. Conventionally, the inspection method of the loosening bolted joint is generally the measurement of the axial tension of a bolted joint by using ultrasonic waves. These methods require the use of special measurement equipment and the human operation. In this study, a smart washer was proposed to detect the loosening without human involvement. The basic principle of how to detect bolt loosening is to the dynamics characteristics of a smart washer system which varies depending on bolt tightening axial tension. A novel bolt loosening detection method by adopting supervisor with adaptive observer is proposed in this paper. The numerical simulations are performed to verify the possibility of the adaptive observer-based loosening detection. Improvement of bolt loosening detection accuracy is confirmed by the proposed method.

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This paper describes a new eddy-current inspection method that enables noncontact detection of the corrosion wastage of a pipe and the flaw/defect on a back of thick-walled magnetic and non-magnetic metal specimens. This paper proposes a method for detecting the faint signal component from the eddy current induced on the back surface of the specimen, by offsetting the strong signal from the surface eddy current with the external sinusoidal signal which amplitude and phase are equal to the detection signal of the sensor. Using this method, it is possible to detect the flaw/defect of the inner surface of a thick-walled pipe from the outer surface and to detect the corrosion wastage from the outer surface of a pipe with lift-off height of tens mm, and to detect the internal crack on the weld zone of a seam weld pipe from the outer surface of the pipe.

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Machine condition monitoring and diagnosis have become increasingly important, and the application of these processes to beam structures and rotating machinery has been widely investigated. The authors previously proposed a stepwise primary diagnosis method using a force identification approach. The method is that the location of the abnormality is firstly estimated using the force identification approach based on the transfer function. When the proposed method is applied to a complex structure, a finite element has many nodal forces. This means that many sensors are required. And the vibration test using an exciter is difficult for the actual structure. Thus in this study, impact test using an impact hummer is adopted for the vibration test, that is one of the improvement methods of regularization. The accuracy of the identification result of the location of abnormality and the relationship of the locations of the abnormality and the impact test are discussed for a beam structure using the previous expression of the virtual additional force. As a result, the correct location of abnormality can be obtained by averaging the results for various excitation frequencies, and the dispersion of the estimation is small when the locations of abnormality and the impact are close.

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This study investigates an evaluation method to analyze the rolling behavior in ball bearings by an ultrasonic technique. The analysis uses the time interval T_I, which is defined as the duration between the two adjacent minimum peaks of the reflection intensity of ultrasonic wave pulse echoes, as an evaluation basis. Since T_I corresponds with the duration between one passing and the next passing of individual balls through the highest loading area in the bearing, its value can present the actual rolling behavior of the balls. Using a reasonable manner to extract each value of T_I, this study demonstrated that the time trend of the variance of T_I was in good connection with that of the autocorrelation coefficient values, rather than the Fourier analysis results, obtained from the measured data of the ultrasonic reflection intensity.

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The object of this paper is to inspect loosening of bolt by projecting an ultrasonic wave on the screw hole side. When an ultrasonic pulse is projected on the screw hole side, the pulse is reflected intricately. So, it is difficult for the conventional ultrasonic inspection. In this paper, the authors focus their attention to frequency modulation of the ultrasonic wave, and attempt to inspect loosening of bolt by using it. In the proposed method, the frequency modulation is observed as a variation of instantaneous frequency of the ultrasonic wave, and the instantaneous frequency is defined as the derivative of a time-dependent phase angle of the ultrasonic wave. When the tightening torque of a bolt becomes small, the authors find that the peak value of the frequency of the ultrasonic wave reflected from a screw hole becomes low, and the time of a peak becomes early. Therefore, the loosening of bolt can be inspected by the variation of the instantaneous frequency. Moreover, it found out by considering screw sectional form geometrically that the number of the reflective courses of an ultrasonic pulse is four. Then, reflection of the ultrasonic wave in a screw hole was modeled, and the cause of variation of the instantaneous frequency was detected.

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In the previous authors' study, the vibration energy harvester of the piezoelectric bimorph cantilever type was proposed for vibration condition monitoring applications of rotating machinery. Proposed energy harvester consists of the surface bonded two Macro-Fiber Composites (MFCs). In this study, energy transfer efficiency was derived from the energy balance equation during the natural period of the proposed vibration energy harvester. The maximum AC power through 114.3 Kilo-Ohm resistor which includes instrument internal resistances experimentally obtained 242.07 microwatt when subjected to vibration source input magnitude of 0.71 (mm/s rms) at the resonant frequency of the harvester (29.42 Hz). The impedance matching between MFCs and the electrical resistive load was effective for maximizing AC power transfer of the vibration energy harvester. Estimated energy transfer from mechanical system to electrical system shows the agreement with the experimentally evaluated generating power during the natural period of the vibration energy harvester with about 13 (%) difference. Estimated energy transfer efficiency was about 33 %.

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This study describes an electromagnetic vibration energy harvester with a nonlinear oscillator. The oscillator with a nonlinear spring can have a bended resonance peak with multiple stable steady-state responses in the resonance band typically the large and small amplitude solutions depending on the initial conditions. We introduce a self-excitation circuit with a variable resistance which can take two values with negative and positive switched according to the level of the response so as to enable the oscillator entrained by the excitation only in the large amplitude solution. In this paper, possible improvement of the resistance switching to realize more rapid entrainment is mainly discussed. A switching control law according to the instantaneous state variables, i.e., the displacement and the velocity, is newly proposed, and the effect of the selection of the threshold values for the switching is examined. The results suggests the possibility of rapid entrainment by tailoring the threshold values according to the characteristics of the excitation.

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Thermoelectric generator can be converted directly into electrical energy to thermal energy. In addition, because there is no moving parts, electrical energy obtained efficiently from a very small temperature difference. That is, thermoelectric devices can contribute to energy-harvesting technology by converting wasted heat into electric power. Monolithic oxide-metal composite thermoelectric generators were fabricated using multilayer co-fired ceramics technology. These devices consisted of Ni_<0.9>Mo_<0.1> and La_<0.035>Sr_<0.965>TiO_3 as p- and n-type thermoelectric materials, and Y_<0.03>Zr(0.97)O_2 was used as an insulator, sandwiched between p- and n-type layers. To co-fire dissimilar materials, p-type layers contained 20 wt% La_<0.035>Sr_<0.965>TiO_3; thus, these were oxide-metal composite layers. The fabricated device had 50 pairs of p-i-n junctions of 5.9 mm × 7.0 mm × 2.6 mm. The calculated maximum value of the electric power output from the device was 100 μW at ΔT = 10 K and operated a radio frequency (RF) transmitter circuit module assumed to be a sensor network system.

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An application example of CUSUM (Cumulative sum) control chart to condition monitoring tasks for a gas turbine installed in a co-generation plant is presented. In order to suppress unwanted alarm caused by slow drift of variables, an improved CUSUM with variable target is employed. The proposed method requires parameter determination that greatly affects fault detection ability of the algorithm. From the viewpoint of ARL (averaged run length), a parameter setting method is proposed. It is also presented that implementation of regression model that estimates values under normal operation conditions along with the CUSUM technique is effective to take into account external variables dependence such as inlet air temperature that affects greatly on the gas turbine performance.

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Lubricating oil is used in various machines and devices. However, lubricating oil is degraded with operating time or usage environment. Degradation causes of the lubrication oil are roughly classified into two types, one is caused by solid particle and other is caused by oil oxidation products. Diagnosis methods for solid particles in lubricating oils have many standards and researches. However, there are few diagnosis methods for oil oxidation products. In this study, we investigated to establish the relationship between the color of contaminants trapped on a filter after filtering degraded oil and properties of the lubricating oil, and developed diagnosis method of the lubricating oils using the colorimetric analysis which paid to the attention to the color of contaminants. These results suggested the feasibility of new diagnosis method of the lubricating oils by the colorimetric analysis.

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This research aims to develop a highly sensitive measurement method of elemental compositions using Laser Induced Breakdown Spectroscopy (LIBS). LIBS is a measurement method to detect elemental compositions in gas, liquid, and solid materials by laser induced plasma. In recent years, various environmental regulations have been strengthened in exhaust gas from engines, thermal power plants, and factories. In this study the LIBS detection limit has been improved using low pressure laser induced plasma process. The generation of plasma is stabilized and a non-equilibrium low temperature plasma state can be attained at 1 kPa pressure range. It was demonstrated that the detection limit of LIBS can be improved by a facer of ten or more using the low pressure LIBS method.

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This paper presents an NI LabVIEW-based Watchdog Agent[○!R] Toolkit developed by the NSF Center for Intelligent Maintenance Systems (www.imscenter.net) at the University of Cincinnati. It is a systematic reconfigurable platform that accelerates the Prognostics and Health Management (PHM) process through simplification of PHM design, modeling, and evaluation. A practical and systematic framework for PHM applications is introduced with comprehensive detail. National Instruments (NI) hardware and LabVIEW software toolkit are used to develop a reconfigurable prognostic platform for rapid deployment and realization of a predictive system. The LabVIEW-based toolkit consists of several key PHM algorithms for health assessment, diagnosis, and prediction. Specifically, the integrated toolkit includes most frequently-used algorithms such as Logistic Regression, Self-Organizing Map, Neural Network, Support Vector Machine and others, To facilitate the use of the toolkit, some integrated (express VI) functions and graphical user interface were also developed to accelerate the process of signal processing, sensor fusion, health diagnosis and prognosis with minimum analyst manipulation and less external knowledge input. The prognostic platform can be easily configured and integrated into the enterprise asset management system to deliver information for maintaining optimal performance of the system.

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[in Japanese]

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In recent years, concern about an environmental problem is increasing more notably. Then, the gas composition measurement technology is becoming much more important in association with tightening of regulations. However, chemical-analysis methods such as gas chromatography are not sufficient to satisfy these requirements from a viewpoint of sensitivity and response. Because of these factors, development of sensitive and fast response gas composition evaluation/diagnostic technology is eagerly anticipated to meet the environmental needs. This research aims at developing the technology which can measure the various compositions with high sensitivity and response compared to conventional equipment. The tunable diode laser absorption spectroscopy using the hollow fiber has been developed to satisfy above requirements. By using a hollow fiber, misalignment of an optical axis and vulnerability of measurement environment such as vibration can be greatly reduced with sensitive and fast response features. It was also demonstrated that this method can be applicable to measure gas compositions in engine exhaust with a range of millisecond response time.

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