Generally, the fuel efficiency of the diesel engine is higher than that of the gasoline engine. More emphasis will be placed on overcoming the fuel penalty caused by reducing exhaust emissions to comply with future stringent emissions regulations. In this study, combustion characteristics of a small diesel engine were experimentally investigated in case of multiple fuel injection strategies including pilot injection, pre-injection and after-injection. In addition, the effect of multiple injection timing on fuel consumption and heat balance was also identified. Engine heat losses were estimated by Hohenberg's empirical equation and were compared with the experimental results. The results indicate that multiple injection along with optimizing injection timing can reduce fuel consumption and heat losses.

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Six-stroke diesel engine has six processes in one cycle. Due to direct EGR in the 2nd combustion process, NO emission is expected to decrease. However, weak mixing in the 2nd combustion process produced much soot. In this study, the six-stroke diesel engine was operated with a constant excess air ratio in order to clarify the effect of swirl ratio and early injection on soot and NO emissions. As a result, soot and NO emission was reduced with supercharge and early injection regardless of swirl ratio, even though indicated torque was hardly changed.

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EGR combustion system is one of the promising ways for NOx reduction in a diesel engine. Since PM and condensable hydrocarbons are contained in the exhaust gas of a diesel engine, they cause PM deposition in an EGR cooler. To improve performance of EGR cooler, the PM deposits in it should be reduced because the heat transfer performance is deteriorated by the deposition. In this study, effects of exhaust gas inlet condition and wall temperature on PM deposition in an experimental EGR cooler were investigated. The thickness of PM deposit was measured by a laser displacement sensor. As results, the thickness of PM deposit in the upstream region of EGR cooler was thicker than that in the downstream region. In addition, the thickness of PM deposit in low flow rate condition of the exhaust gas was thicker than that in high flow rate condition of the exhaust gas. Also, PM deposit layers were separated from the wall in the case of lower wall temperature. The separation was probably caused by condensation of water in the exhaust gas.

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Effects of ambient temperature, O_2 concentration and injection duration on combustion and emission characteristics of diesel spray under high temperature and high pressure ambient were experimentally examined using a constant volume vessel. It is confirmed that the ambient temperature /pressure has large effect on the shape of heat release rate, the ignition delay and the combustion duration. As the decrease of ambient O_2 concentration, both of the ignition delay and the combustion period become longer. The NOx emission increases with the increase of ambient temperature and the increase of O_2 concentration. The CO emission increases abruptly under the low ambient temperature and the low O_2 concentration condition.

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Effects of O_2 concentration and injection duration on ignition and combustion characteristics of diesel spray in a high temperature and high pressure vessel was experimentally examined under the ambient condition of 3 MPa and 985 K. The ambient O_2 concentration was changed from 21 % to 9 %. The flame temperature and the soot production were quantified through an image analysis technique using 2-color method. From the systematic experiments, it is confirmed that, as the decrease of O_2 concentration, both of the ignition delay and the combustion duration becomes longer and the flame temperature becomes lower. However the injection duration has little effects on the ignition delay and the flame temperature at the initial stage. On the contrary, O_2 concentration and the injection duration have the combined effect on the soot distribution in flame.

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The high-speed observation of dimethyl ether (DME) combustion spray in constant volume vessel was conducted under engine-like high-pressure and high-temperature condition. DME spray model coupled with oxidation reaction model was improved on the basis of the experimental results. Using the improved spray model, the effect of injection pressure and nozzle diameter on CO and NOx formation was examined by numerical analysis.

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Using high temperature vessel in which we can make about 30 μm droplet, we tried to watch n- hexadecane ignition. We use heating wire which is parallel with injection axis to make high temperature. We found there are two phenomenon by the difference of pressure and temperature, evaporation and ignition. If in higher pressure, a droplet ignite by lower temperature. When a droplet ignite, droplet's diameter reduction was not happen before it ignite.

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Recently, because hydrogen is renewable energy it attracts attention for react of the environmental pollution and the resource depletion by use of a fossil fuel. There is the internal combustion engine as the power source using hydrogen. Since the internal combustion engine can divert conventional technology and parts, it has advantages such as low cost and high durability. Since minimum ignition energy is lower than other fuel, hydrogen tends to cause abnormal combustion. However, the rotary engine is capable of controlling the abnormal combustion of the hydrogen relatively easily. In this study, the hydrogen rotary engine (HRE) is developing. In this experiment, it aimed at the improvement the stability of the 20cc HRE by control of the temperature rise. Therefore, 20cc HRE which adopted the water cooling system was operated. Moreover, the stability and the output characteristic by control of the temperature rise were evaluated. Characteristic of the 20cc HRE was evaluated by the propeller and the eddy current dynamometer. As a result, 20cc HRE could be operated for more than 80 minutes with the propeller. Moreover, maximum output power was 0.58 kW generated at the 10000 rpm.

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This study aims at investigating the effects of engine specifications on exhaust emissions and performance for dual-fuel engines with lean natural gas premixture. For this purpose, the experimental results were compared between two engines with different stroke volumes. The test engines were based on single-cylinder four-cycle naturally aspirated direct injection diesel engines. To supply pilot fuel, an electrically controlled common-rail injection system was installed and the main fuel, natural gas was continuously supplied into the intake pipe. The results show that the overall characteristics of NOx, unburned species, combustion variation and thermal efficiency are similar to each other in equivalence ratio sweep and injection timing sweep tests. Higher heat release rates were observed for the smaller engine, which corresponds to lower THC emission and higher NOx emission for relatively later injection timings of pilot fuel.

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In this study, the influence of the microwave irradiation on the flame propagation of primary reference fuel (PRF) pre-mixed gas has been investigated using a constant volume vessel with a 2.45 GHz-magnetron generator. Flame propagation speeds were measured at equivalence ratio of 1.0, initial pressure of 0.5 MPa, and initial temperature of 373 K. A shadowgraph method was used to visualize the flame front When the microwave power was irradiated in the output power range 0-100 W, flame propagation speeds was enhanced with increasing microwave power. Microwave effect was observed during the initial acceleration period from 0 ms to 15 ms.

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The characteristics of aldehyde emissions from butanol blended fuel were evaluated using non-modified DI diesel engine run on the gasoil mixed with butanol isomers in various ratios. Aldehydes were analyzed in the form of gas by FT-IR for detecting formaldehyde, acetaldehyde and acrolein and GC/FID for detecting butylaldehyde and isobutylaldehyde. With increase of butanol content, total aldehydes (including formaldehyde, acetaldehyde and acrolein) slightly got increased especially in low load area. The fuel iBGO40 produced much aldehyde than BGO40, probably because of longer ignition delay having roots of lower ignitability of Isobutanol than that of 1-Butanol. In iBGO40, isobutylaldehyde which stood out in low load area got nearly undetectable in high load area although butylaldehyde continued to exist.

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The combustion characteristics and exhaust emissions of the dual fuel diesel engine fueling with coconut oil methylester (CME) and low calorie bio-gas (LCG) are investigated by comparing to the CME/CNG, RME(Rapeseed oil methyl ester)/CNG, RME/LCG, GasOil/LCG, GasOil/CNG dual fuels. The results show that the operable condition of CME/LCG is almost the same as that of the other dual fuels. The thermal efficiency of CME/LCG is almost the same as that of the other dual fuels. LCG dual fuels have lower NOx and Smoke emissions compared with the other test dual fuels. It is concluded that CME/LCG is best among the test dual fuels.

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It is well known that bio-diesel fuel produces much deposit on engine components compared with diesel fuel (DF). Deposit accumulated in combustion chamber causes engine troubles and deterioration of engine performance and pollutant emissions. Therefore, it is important to elucidate the mechanism of deposit formation to maintain the performance for a long time. However, it is very difficult to perform the deposition test using actual engine. In this study, single fuel droplet was dripped on a hot surface repeatedly and evaporation deposit formed on it were analyzed. Test fuels were DF, DF to which 10wt% oleic acid was added (DFO10) and DF to which 10wt% methyl oleate was added (DFMO10). As a result, the mass of deposit formed from DFO10 were more than that formed from pure DF under the low surface temperature condition. However, under high surface temperature condition, DFO10 formed less deposit than pure DF. The mass of deposit formed from DFMO10 were less than that formed from pure DF both under the low and high surface temperature conditions.

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Two-color method is widely used for the measurement of the combustion temperature of a diesel engine because of its simplicity of the measurement system. Two-color method uses the radiance from soot particles to estimate temperature of the combustion fields, therefore, it is impossible to apply the method for the measurement of non-sooting flame such as hydrogen flame or methane flame under atmospheric pressure. In this study, Particle-seeded two-color method where solid particles are seeded to the combustion field and the radiance from the seed particles are used to estimate the temperature is proposed to expand the application area of the two-color method. SiC particles are selected as seed particles and strong luminous flame is observed from methane-air premixed flame with seed particles at atmospheric pressure and equivalence ratio is unity. Temperature distribution is estimated from the radiance of the particles. The estimated temperature ranges from 2300 to 2800K and is higher than adiabatic flame temperature. The primary factor of the overestimation is the inappropriate estimation of the emissivity of the seed particles.

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Dimethyl ether (DME) spectroscopy near 3.3 μm using a distributed feedback (DFB) laser has been studied to determine the appropriate absorption line for DME detection in fuel sprays or combustion emission monitoring applications. The direct absorption spectrum of DME has been measured in the 2979.6-2980.5 cm^<-1> region. As H_2O has absorption lines in this region, wavelength calibration was performed using H2O absorption lines. A wavelength of 2980.07 cm^<-1>, at which there is no interference between the DME and H_2O absorption lines, was selected for the DME concentration measurements. The direct absorption signal intensities' dependence on DME concentration and pressure were obtained. These signal intensities were found to be proportional to the sample concentration and pressure, respectively. From these signals, the detection limit for a signal-to-noise ratio of 2 at 5 kPa was found to be 0.05%.

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Heat transfer to the wall through the flame propagation of premixed combustion was investigated in a constant-volume vessel. The local heat-flux was measured using a thermopile sensor at various ignition-positions and gas-mixture conditions, in addition to heat-release rates and shadowgraph images of flame development. The results show that local heat-flux depends on both the flame temperature and the pressure in the vessel. Particularly when a flame front approaches toward the wall, a gradual increase in local heat-flux is observed as a pressure-rise prior to a rapid increase at the time when a flame front reaches the wall.

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Particulate Matter (PM) contained in diesel exhaust emission is known to cause harmful effect to respiratory system. Diesel Particulate Filter (DPF) is used to reduce the amount of PM contained in diesel exhaust emission. The amount of PM collected in DPF can be estimated from pressure drop of exhaust gas passing through DPF. For the purpose of analyzing factors causing pressure drop change, we, in this paper, have developed an experimental method that is effective to sequential DPF-internal observation. PM accumulation observation experiment using the method has been conducted and has demonstrated that the experimental method enables the acquisition of sequential DPF-internal images. Analysis of these images indicates quantitative relations between the PM accumulation behavior and pressure drop change. In addition, we have investigated the feasibility of this experimental method under the condition where high-temperature emission flows into DPF. Consequently, the proposed observation method must be modified to overcome the problem of dew condensation under the high-temperature condition.

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A detection efficiency of the particle number counter (PNC) below 10 nm were measured using a measurement system which is the particle measurement programme (PMP) methodology with the PNC which D50 is 2.5 nm (PNC_2.5) and normal PMP PNC (PNC_23). The detection efficiency had some uncertainty due to difficulty in generating particles at sufficiently high concentrations with diameters below 10 nm. Then exhaust particle emissions from gasoline direct injection (DI) passenger car were measured with this system. Sgnificantly increased PN was obsereved in the cold start mode. However this incleased emission is due to the particle over 23 nm. An emission of the particle under 23 nm was obsereved during a high speed operation.

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This study aims, for hybrid electric vehicle, to develop a controller for reducing torque ripple caused by fuel combustion in the combustion engine and reaction torque from road surface. Road surface reaction force and load torque are not measurable directly because the corresponding sensors cannot be easily attached due to lack of space for attaching in the engine structure, cost and fault diagnosis system of the sensors. Moreover HEV system is nonlinear. Therefore control system for reducing torque ripple should be designed under the assumptions where road surface reaction force and torque load are supposed to be unknown, and HEV system is nonlinear. In this paper, a control method for reducing the torque ripple by controlling the HEV assist motor is proposed. This control method required the only measurable crank angle. The effectiveness of the control method is verified experimentally by implementing the control law in a HEV physical simulator. HEV physical simulator consists of a power train, an engine alternative motor and a slider crank. As a result, the torque ripple is reduced by 33 percent.

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The robust design of complex systems with the facility of waste incineration power generation system and the waste heat utilization is examined in this study. Environmental load values in the operation of waste incineration power generation facility are estimated by using the life-cycle impact assessment method based on endpoint modeling LIME2. The optimum combination of level is determined to minimize the effect of variations in the characteristics of wastes by using the experimental design method based on the SN ratio. The use of the LIME2 and the SN ratio, it is possible to perform a robust design for the characteristics of wastes variations in waste incineration power generation facility in consideration of both economy and environment.

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This paper presents on experiments for parameter identification of rotation stiffness resistance coefficient k_θ of water and restoration force coefficient γ_θ to gyroscopic moment based on non-autonomous basic equations induced from autonomous roll stability equations of a floating body, wind force moment and gyroscopic moment of rotor dynamics about a single rotor boat model with various wind speed from portside and starboard in a small pool . The tilt angle of the rotor boat was measured by 3D accelerometers, and restoration angle was computed. The non-linear property of the stiffness coefficient identified and the good results for simulation on roll stability were obtained.

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This paper presents a construction of a laboratory size of mini batch AUS production system, an improvement of its measurement and control method, a scheduling problem for minimum production time operation under a maximum current restriction condition like 2 out of 3 operation within double dilution pumps and a warm stirrer using Gunt chart. Moreover, a mathematical model on the system was tried to make a critical path, that is, the solution process of urea solid to be short time in all process.

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This paper presents vehicle steering control for target parking states - position and direction - by predictive control without target trajectory. One of the major issues is to asymptotic steering angle toward zero at the same time that vehicle converges target parking states. In order to achieve them, the predictive control that minimizes difference between target and predicted postions when some of the future steering angle is assumed as zero is applied. Simulation results when the initial states of the vehicle are defined at random are presented to demostrate the effectiveness of this control.

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When agricultural machines are operated on pavements, the vibration and noise caused by the interaction between the tire lugs and the road surface are inevitable. Therefore, it is important to investigate the lug excitation force occurring on rolling agricultural tire in order to clarify the vibration generation mechanism. In our previous study, it is con- sidered that the dynamic behavior of rolling agricultural tire is influenced by the vibration characteristics of the tire. Further, only the rigid modes among the natural modes could affect the rolling tire behavior. So, we modeled the tire as a circular rigid ring supported on an elastic foundation with contact model. This rigid ring model can be valid to investigate the lug excitation force, while it is necessary to measure forces acting on tire shaft. In this study, the test equipment is modified to measure tire shaft and forces acting on tire shaft at rolling are measured. From the obtained results, the shaft force characteristics are investigated.

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The purpose of this study is to estimate the engine output torque from the crank shaft angle. The crank shaft angle is affected by the drive train, vehicle body dynamics, and road surface condition. Hence, the drive train model and the vehicle body dynamics are derived to take their influence into account. The drive train model and the vehicle body dynamics model are derived by projection method. The unknown parameters of the drive train model are identified. Single passenger vehicle (hereinafter SPV) is used as an experimental system. The SPV has some sensors, a pressure sensor for measuring the cylinder pressure, rotary encoders for measuring the rotational angle of the crank shaft, the front sprocket, and the tires, and a torque sensor for measuring the transmitted torque from the drive train to the front sprocket. The measurement instruments are developed to realize on-line measurement on FPGA. Its effectiveness is experimentally verified.

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This paper reports about the lane-changing collision prevention system by control the yaw moment. In recently, many cars increase in the world. In particular, the BLICS area increases a car than advanced country. The automobile accident number occurs a lot in a developing country. The reason that driving technical leading for the driver is out of direction. Therefore the car security technology development is necessary. There is the thing which the car security technology is developed. For example, there is the collision prevention system of the front direction. However, I can't prevent all of traffic accidents by this system. Therefore I need my research. The aim of my research develops control system to assist the driving for the driver. And it is necessary to make a control system for the establishment of this system. In order to realize this program uses Simulation to calculate equation of the car motion. This paper reports the automobile fundamental translator movement.

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Due to the space limitation on the driving tire, small electric vehicles employed mechanical braking system rather than hydraulic braking system. For the same reason, anti-lock braking system (ABS) which is a basic skid control method is difficult to install on the driving tire. Although the mechanical braking system is compact, the rigidness and the response performance of the mechanical braking system is lower than hydraulic braking system. During braking on an icy road or in an emergency braking, the possibility of an accident is increased. To improve the safety and stability of the small electric vehicle, our past research has done a simulation model of hydraulic-mechanical hybrid brake system with ABS and regenerative brake control. The simulation result shows that ABS and regenerative brake control can prevent tire locked during braking on an icy road. To validate the simulation result, in this paper, we present the experimental method to control the motor on the slip condition. The experimental result shows that the skidding phenomenon can be prevented by controlling the rotation speed of the motor.

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Concern over fuel consumption and ride comfort of a vehicle has been increasing in the recent years. Furthermore, environmental impact of the petroleum-based transportation infrastructure, along with the peak oil, has led to renewed interest in an electric transportation infrastructure. The problem with the electric vehicle in the market now is that the angle of cornering is not small enough to be fully used in narrow road. This research will explain about motion characteristic of rear wheel steering small Electric Vehicle (EV). The difference in torque from both rear wheel is used to control the steering of the vehicle and thus give more freedom on the maneuvering of the vehicle. This will improve the cornering of the vehicleand has the advantage of moving easily in a small space. In this research, two types of simulation is done which is the different amount of torque input is given in the same direction while the second simulation process is the same amount of torque input is given but with an opposite direction.

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As car manufacturers progress in creating electric based transportation, demand on the research of stability, controllability and feasibility on electric vehicle increases. The electric powered and by-wire control technology allow for manufacturers to build an independent four wheels steering (i4WS) of an all-wheel drive small in-wheel electric vehicle. In past research, we have determine the advantages of a all-wheel drive (AWD) four wheel steering (4WS) small electric vehicle based on steering performance during low speed in comparison to two wheel steering (2WS) by using numerical simulation. During low speed, a AWD 4WS in-wheel electric ve hide is capable of cornering in a short radius and has a higher respond to driver's steering with the assist of passive control rear wheel steering. In this paper, a research on active control of 4WS in-wheel small electric vehicle during high speed is proposed by using a numerical simulation. In the simulation, a 4WS in-wheel small electric vehicle is designed with a non-linear model. A feedback control cannot be executed directly to this model as a result of yaw rotational speed coupling with the velocity components as expressed in dynamic motion equation. Thus, in this research we attempted to find a possibility that a controlled linear model can be feed-forwarded to the non-linear model. A linear quadratic regulator (LQR) was used to achieve optimal control in the linear model. At the end of the paper, the results of active control of 4WS in-wheel small electric vehicle correspond to cornering beyond stability clearance speed is shown.

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To achievement of quick response and detailed resolution both of the electronic throttle, the back-stepping control has been examined in our work. The two step approach was applied to design the back-stepping control system in shape near the PID control. In our works, the derivative term was added for the response improvement in the first step, and the static-friction was compensated for the stick prevention in the second step. A simulation study was executed by using the Matlab/Simulink. The physical model of the electronic throttle was used to be a control object. As a control model, the 2^<nd> order linear model and static-friction model was incorporated in the back-stepping algorithm. The wide-opening test and the narrow-opening test that represents performance evaluation of electronic throttle showed a both excellent control characteristic.

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The PID control is widely used to control mechanical systems. It is useful to assign desired stability margins. Conventionally, the process has been approximated to model process because of appointing stability margins of the control system. However, there is a problem that a difference occurs between true process and similar process. There is a method to design the control system in limit cycle response to solve it. However this method is able to set only phase margin. In this paper, using the limit cycle to design control system and adding a delay element to that. This method can design stability margin with a desirable value. Experiment result is shown the usefulness of this method.

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In the transport system of a thin-steel-plate production line, there is a problem that the quality of the plate surface deteriorates over time because the plate is usually in contact with rollers. To solve this problem, electromagnetic levitation technologies have been studied. However, when an ultra-thin and flexible steel plate is to be levitated, levitation control becomes difficult because the ultra-thin steel plate undergoes increased flexure. To overcome this problem, we have proposed the levitation of an ultra-thin and flexible steel plate that is bent to an extent which does not induce plastic deformation. It has been confirmed that vibrations are suppressed and levitation performance is improved by bending a steel plate. In this study to elucidate the levitation stability under disturbance, random disturbance was input into the levitation system and bending levitation experiment were carried out using ultra-thin steel plate with a thickness of 0.18 mm.

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The purpose of this study is to provide load sensor-less system for our developed small size press machine. For this purpose, it is necessary to grasp the characteristics of the press machine. The press machine is composed of a ball screw, a cog belt, a motor and a slide unit and has several spring characteristics. So, we carried out experiment to derive the spring characteristics of press machine with work piece. Experiment content, is to derive models by measuring with a sensor the relationship load and displacement of each element, applying the least square method to the result. And we derived models for each element of the press machine with work piece from the experimental results. To verify derived models, we performed experiment to get the desired load by position control of the motor. And we confirmed the relationship between the reference and resultant load. On the other hand, it was confirmed that the experiments were performed under the same conditions as the actual pressing of the control using derived models, to reach the desired requirements. As a result, we can form a control system for the load sensor-less press machine.

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This paper investigates how to stabilize an inverted pendulum without electric devices using gravitational potential. For this purpose, we propose a wheeled inverted pendulum placed on a sloop that consists of a wheeled double pendulum whose second pendulum transforms the gravity force into a brake force acting on the wheel. We derive equations of motion and stationary states of this system and investigate their stabilities. The result implies that a standing position of the first pendulum becomes asymptotically stable under the condition bounded by the infimum of descent velocities and a Hopf bifurcation point. In the stability region, the proposed wheeled pendulum moves down on the sloop to stabilize the first pendulum in the standing position while dissipating the gravitational potential through the brake mechanism.

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The dynamics of the two-wheeled inverted pendulum type vehicle is an unstable system, the control system is required for the stabilization of the personal mobility. However, in the case of controlling the nonlinear system, such as inverted pendulum, it is necessary to linearize the nonlinear system. A method of linear approximation of an equilibrium point about using the first order approximation of the Taylor expansion to approximate linearization method is widely used. This method is not widely effective for large systems of non-linear operation area. In this paper, it is consider by comparing an estimate of the attitude angle of the linear model and nonlinear model that assumed to periodic vibration of the pendulum system by the operation of the passenger.

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This paper presents the development of a control system for motion assist device using McKibben pneumatic actuators. Proposed control system utilizes feedback control with a load observer which estimates exogenous load acting on human arm. The feedback controller calculates physical work done by the necessary air pressure. Experimental results indicate the validity of the proposed control system.

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Assistive devices can be worn to enhance the wearer's strength. Such devices need to be safe for the wearer Pneumatic actuators are suitable for driving those devices because they are highly safe for humans. However, the responsiveness of pneumatic actuators is lower than that of electric actuators due to the compressibility of air. In this paper, we use the initial burst in muscle activity to avoid delay in activating our pneumatic arm assistive device for the wearer's motion. The initial burst that always occurs first in voluntary movements indicates the wearer's preparation for movement. It is detected based on an inflection point on the cumulative addition curve obtained from a surface electromyogram signal. Experimental verification shows that the activation of the assistive device prior to the wearer's actual movement is possible.

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Running stability of the high-speed-moving vehicle subjected to the seismic excitation is investigated. The analytical model of one vehicle consists of one body, two trucks and four wheelsets, and has a total of 21 degree of freedom. Some springs of vehicles called stoppers are modeled as a nonlinear spring in order to reduce relative displacements. We employ the risk rate of rollover of the vehicle as evaluation index in order to evaluate running stability of the high-speed-moving vehicle. The vehicle is excited by seismic inputs. Two types of seismic waves are introduced from the shape of the acceleration response spectrum. The effect of the predominant frequency on the risk rate are investigated. Furthermore, we select some important modes, which are dominant in the seismic response, from 21 modes. The reduced order model of vehicle is constructed.

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This study aims at quantifying malfunctioning in the reciprocating compressor and establishing a new monitoring technique. We propose a mathematical model (six degrees of freedom) in which deterioration and damage are expressed by changing model parameters. We use our small experimental equipment to examine the natural frequencies and natural modes based on the vibration testing. Then, we perform parameter identification using the natural frequency characteristics and examine the model parameter estimation method, which uses the relationship between the natural frequency characteristics and the frequency characteristics during operation. As a result, it was confirmed that the estimation method enables to express vibration characteristics using the error function about the natural frequency characteristics. In this way, it is possible to quantitatively evaluate the status of the sliding portion and the connecting part to determine the cause of the failure point or malfunction.

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This paper describes characteristics of the electricity generation using a piezoelectric element that is installed at the center of a circular plate, which is constructed of aluminum and is subjected to the harmonic point force. In the theoretical study, the electromechanical coupling equations are derived from the relationship between characteristics of the plate vibration with the piezoelectric element and the electricity generation based on the piezoelectric effect, and then the electricity generation efficiency, which is the ratio of the electric power harvested from the piezoelectric element and the mechanical power supplied to the plate, in predicted from then equations. These theoretical results are verified by experimental results obtained from an actual experiment, which is examined using an experimental apparatus that emulates the analytical modal. As a result of the theoretical and experimental consideration, it is shown that the electricity generation efficiency is suppressed only by the installation of the piezoelectric element on the vibration surface. Moreover, it is clarified that the efficiency decreases with increasing the plate thickness.

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This present paper describes the effect of vibroacoustic coupling on electricity generation systems using piezoelectric elements, which are installed at the center of plates that are mounted at both ends of a cylinder. Vibroacoustic coupling is derived from not only the relationships between the plate vibrations and internal sound field of one cylinder but a structure connecting two cylinders. In this study, the cylindrical structure with thin end plates is subjected to the harmonic point force at one end plate and a natural frequency of the end plates is selected as the forcing frequency. The resulting vibroacoustic coupling is then analyzed theoretically and experimentally by considering the dynamic behavior of the plates and the acoustic characteristics of the internal sound field as a function of the cylinder length. These results clarified the length, which maximized sound pressure level inside the cavity. The theoretical results are validated experimentally through an excitation experiment using an experimental apparatus that emulates the analytical model. Moreover, the electricity generation experiment verifies that sufficient vibroacoustic coupling can be created for the adopted systems to be effective as the electricity generation system.

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As a study of maneuverability of the inverted pendulum vehicle, handle roll rotation and yaw rotation are investigated. The experimental vehicle can switch between handle modes and is equipped with a Bluetooth communication function for measurement of the state of the vehicle. We compared handle operations by changing three gains, that is, high, intermediate and low gains. The experimental course was a slalom course with two cones placed at an interval of 1.8 m. The research participants made one round trip. The trajectory of the vehicle was measured by a three-dimensional motion analysis device called VICON. We evaluated handle operations from steering angle, travel time, the trajectory of the vehicle, and a questionnaire. As a result,

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To prevent the global warming, it is desired to develop eco-friendly electricity generation technology. For this sake, various types of generation technology utilizing renewable energy, such as wind power and solar power, have been already developed and are in operation. But the amounts of electric power generated by these technologies are smaller than those by thermal power or nuclear power plants. Thus it is important to increase the diversity of the electricity generating methods. In this study, fluid-elastic vibration of tubes subjected to cross flow will be utilized. This vibration sometimes causes the failure of tubes in the heat exchangers such as a boiler and a steam generator, and conventional researches focus on the methods to suppress this vibration. But if we focus on this vibration from the other aspect, this vibration has very large energy, because tubes take in fluid energy very efficiently. Therefore, we propose a new method to generate electricity from fluid-elastic vibration of tubes. Here, we fabricate a fundamental flow-induced vibration model of tubes and investigate the possibility to harvest energy and to generate electricity from fluid-elastic vibration. We employ electromagnetic induction as electric power generating.

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Because the senior car mute demand for car interior, sound absorbing material are widely used for proofing in automotive. Two path exists in the sound-absorbing material. The first is a skeleton path of the sound absorbing material. The second is the air path of the sound-absorbing material. When the vehicle is traveling, vibrations generated from the engine to vibrate the vehicle body frame, the vibration is transmitted to the rubber sheet in the air path and backbone path of the sound absorbing material. Sound occurs rubber sheet is vibrated. In order to improve the acoustic design of the automobile cabin, the characteristics of the sound absorbing material is required. In this study, rubber sheet and sound-absorbing material is used .The model primarily the mechanical dynamics and acoustic engineering vibration phenomena in sound-absorbing material, to analyze the acoustic characteristics.

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This research is directed to xylophone. Xylophone is musical instrument that has side-by-side wooden sound board in general, it is intended for those with resonance tubes under sound boards in this research. I taken out one set of the resonance tube and sound board, treated as system, which led the resonance tube and sound board. Theory of the system that led the two has not been established yet. This research is finally aimed establishment of theory. I was produced in resonance tube and sound board based on the 'la' of the sound of basic. Sound boards of xylophone are carved arched lower, but I was using the aluminum, using rectangular solid in this research. Resonance tube was using vinyl chloride. The result of hanging the sound board, measuring some points sound pressure with or without the resonance tube, I found that there are differences in sound pressure distribution. Therefore, I can be seen that the resonance tube has brought something to the effect space or sound board.

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The comparison method between input powers and contribution rates from power sources to a simple structure consisting of two flat plates and a partial car model consisting of four subsystems in machine operation determined by SEA and inverse matrix TPA was proposed by the authors in the past studies, and the validity of this method was shown. However, it is necessary to extend to the sound fields in order to realize utilization of this comparison method. In this paper, the method is validated through numerical analyses, using a finite element method of a simple structure consisting of seven plate structure including one internal sound field. As a result, the SEA vibrational input power is spatial averaged over each subsystem quantitatively agrees with the TPA input power expressed as the product of the force and velocity at the excitation point. The SEA acoustical energy qualitatively agrees with the TPA acoustical energy. The contribution rates from a power source, when applying the new method to make a comparison between the SEA and TPA results, the effectiveness of the method has been verified.

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The combination of micro-perforated panel (hereafter abbreviated to "MPP") and honeycomb core is supposed to be one of promising sound absorbers in comparatively lower frequency range. We fabricated MPP and honeycomb core by a few kinds of material, and its sound absorption coefficient at normal incidence was measured by two microphones in an acoustic impedance tube. It is observed that the combination between metallic MPP having a few millimeter's holes and paper honeycomb core, drastically influenced the frequency response curve of sound absorption coefficient. In order to interpret such interesting phenomenon, the coupled vibration among Helmholtz resonance, MPP and elastic vibration of honeycomb structure are considered and numerically analyzed by simple CAE model.

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A high-powered suction truck has often been used at night in order to avoid traffic confusion in major cities in Japan. The noise reduction of the high-powered suction truck has been required from the environmental point of view. Root blowers have been widely used in order to make strong vacuum of a powerful suction vehicle. However the noise from the end of complex pipe line becomes large. Then the silencer has usually been connected downstream from a root blower in order to reduce the noise. However, the noise of the last end is still loud. In this study, it was clarified that the components set downstream the root blower caused resonance by measuring the sound pressure and the 27.1dB reduction could be obtained by adding an insertion silencer to a cooling-water catcher. In this paper , the noise reduction mechanism will be clarified by BEM analysis and the silencer theory.

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In this study, we investigate the change of structural dynamic reliability of piping system supported by elasto-plastic damper with gap subjected to nonstationary random input excitation, when a width of gap is changed. The elasto-plastic damper has a bilinear hysteretic characteristics. The piping system is modeled by L-type piping systems with a weight at one end. Analytical model of piping system is constructed by using finite element method. The support force is given by bilinear model. The inputs are given by narrow range white Gaussian noises. In this study we can consider the structural integrities of both the piping system and the elasto-plastic supporting devices by taking two indexes; dynamic reliability of pipings and accumulated energy of support into account. Furthermore, the effect of parameters such as gap width are searched. Numerical simulations are perfomed using L-type piping system model for random inputs based on probablistic vibration theory. This study is applicable to the seismic design of piping systems supported by elasto-plastic dampers subjected to the actual earthquake inputs.

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