The existing phenomenological soot model, which unburned fuel is considered soot precursor, cannot predict the soot emission of alcohol blend fuel with high accuracy. Therefore, we proposed to introduce the coefficient Keff including the concept of Threshold Sooting Index (TSI) which quantitatively expresses the fuel sooting tendency of blend fuel. In this research, for more accurate prediction of soot emission we conducted the elementary reaction analysis of blend fuel using reduced mechanism for n-heptane, n-butanol and Polycyclic Aromatic Hydrocarbon (PAH) with 76 species and 349 reactions. Based on the clarified relationship between pyrene (A₄) and TSI, we derived the equation through which Keff is calculated. By using the equation, the accuracy of the soot emission prediction was improved particularly in the low alcohol blend rate.

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The effects of unburned-gas temperature and radiative heat loss on the intrinsic instability of premixed flames in cryogenic environment were studied. Unsteady reactive flow was calculated numerically, based on the compressible Navier-Stokes equation including chemical reaction and radiative heat loss. As the unburned-gas temperature became lower, the growth rate decreased and the unstable range narrowed, which was due to the reduction of the burning velocity of a planar flame. Considering radiative heat loss, the growth rate was smaller and the unstable range was narrower. On the other hand, the normalized growth rate increased as the unburned-gas temperature became lower. This was due to the strength of thermal-expansion effects and to the enlargement of Zeldovich numbers. Furthermore, cellular flames appeared owing to intrinsic instability. As the unburned-gas temperature became lower, the normalized burning velocity of a cellular flame increased. When radiative heat loss was considered, the normalized burning velocity of a cellular flame increased at small Lewis numbers and remained at Lewis number of unity.

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This paper presents a controller design approach for load devices to provide robust properties against variations in resonant frequencies and disturbance forces in the mechanism. In the device, a pneumatic actuator and a voice coil motor are combined as a dual-stage to expand the servo bandwidth of the load control. The control performance, however, is deteriorated by disturbances due to the interference force between the actuators as well as the frequency variation in the mechanical resonance. In this research, therefore, a robust controller is designed by PQ method and H_∞ control framework against the disturbances of the dual-stage actuator. Effectiveness of the proposed approach has been verified by frequency analyses and experiments using an actual load device.

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This paper proposes a two-stage actuator system that consists of a coarse actuator driven by a ball screw with an AC motor (the first stage) and a fine actuator driven by a voice coil motor (the second stage). The proposed two-stage actuator system is applied to make a wide-bandwidth bilateral control system without needing expensive high-performance actuators. In the proposed system, the first stage has a wide moving range with a narrow control bandwidth, and the second stage has a narrow moving range with a wide control bandwidth. By consolidating these two inexpensive actuators with different control bandwidths in a complementary manner, a wide bandwidth bilateral control system can be constructed based on a mechanical impedance control. To show the validity of the proposed method, a prototype of the two-stage actuator system has been developed and basic performance was evaluated by experiment. The experimental results showed that a light mechanical impedance with a mass of 10 g and a damping coefficient of 2.5 N/(m/s) that is an important factor to establish good transparency in bilateral control has been successfully achieved and also showed that a better force and position responses between a master and slave is achieved by using the proposed two-stage actuator system compared with a narrow bandwidth case using a single ball screw system.

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Simple adaptive control (SAC) is known as a control method that keeps control performance even if plant properties have changed. However, there is a problem such that the vibratory output occurs in the transient response when SAC is applied to a vibration system which includes anti-resonance modes. This paper clarifies the reason and an improvement method of the problem. The reason why the vibratory output occurs is that the vibratory input corresponding to the anti-resonance frequency occurs by the structure of SAC. In order to overcome the problem, it is shown that designing of a parallel feedforward compensator (PFC) appropriately is effective. The PFC should be designed such that the frequency response of an augmented system which consists of the plant and the PFC does not have anti-resonance properties even if the plant includes anti-resonance modes. This paper proposes a PFC design method to overcome the problem such that the gain of the augmented system is matched to the one of a pre-specified desired model. Furthermore, the PFC must give the ASPR property to the augmented system. The design problem is described as an optimal problem of the frequency response matching under some restrictions on the ASPR property. The optimal problem is solved using the distributed particle swarm optimization which is effective for a non-convex problem. The effectiveness of the proposed method is verified by numerical simulations and experiments.

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Metallic interfaces in mechanical structures cause dynamic damping property. It is very effective to apply this good damping property to engine power plant in order to reduce noise and vibration, however, it is difficult to use dynamic damping property effectively because the mechanism of the damping behavior is not clarified completely. Accordingly, the experimental measuring device was made for the purpose of estimating dynamic damping characteristics of metallic interfaces quantitatively. Applying controlled vertical load to contact surface between metallic specimens, after that, exerting shearing reciprocal force to the interface by linear motion drive mechanism, relative displacement and applied shearing force are measured simultaneously. The dynamic characteristics of contact interfaces are identified as a result of describing hysteresis loops from measuring data. The measuring device was shown to measure damping property precisely in wide frequency range.

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Automated Manual Transmission (AMT) is adapted to commercial trucks as high efficiency automatic transmission. In this paper, we describe a result of control experiment of electromagnetic actuator developed for AMT's shift unit. There is a drawback that the electromagnetic shift unit has low controllability since there is large response delay of the electromagnet current to the voltage. It is considered that the low controllability is due to the fact that the inductance of the electromagnet is so large that it can't be ignored, and it changes depending on applied current and control positions. Therefor the shift unit has a problem that it can't stop at the target gear in position and the large noise occurs when it hit the stroke stopper. In order to improve the controllability of the shift unit, PID control, sliding mode control (SMC), and energy evaluation control (EEC) are applied to the control of the shift unit. EEC is a new control rule that we proposed and this control rule is based on the bang-bang control theory. Each control parameters of PID, SMC, EEC was set to 3 parameters and Taguchi method was used for optimization of these parameters. As a result of the experiments, it is found that the EEC is most suitable for the control of the shift unit. Validity and usefulness of the EEC are confirmed from this result.

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Japan entered a super-aged society, and an excretion care of nursing care is a serious social problem. The excretion care causes physical and mental stress to both caregivers and recipients. In this study, we have been developing new nursing care equipment for reducing the stress of the excretion care. The equipment consists of “Support system” and “Toilet system”. The support system assists the recipient to get up from a bed and walk without help, and the toilet system assists of toileting. The toilet system can detect the position of an anus by using an infrared thermal camera, prevent odor dispersion by attaching the device to the buttocks, and capture feces in a bag. And wiping machine of the device can wash an anus using foam. Here we investigated the estimation experiment which checks the efficacy of foam for washing the anus using an artificial buttocks and an artificial stool. Comparing the number of wipes and residual percentage of filth on the artificial buttocks after the device cleans the buttocks. In the result about whether or not foam is present, the number of wipes and the residual percentage when use foam was less than half when don't use. Therefore, we confirmed that using foam removes more fecal filth.

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Walking is the human basic moving pattern and the elementary motion for human health promotion. In case of trying various measures as the moving pattern for human health promotion, the most traditional moving pattern called Nanba walking based on the biomechanics of the human body has been put into practical use. It has been thought that Nanba walking is actively focused because it is very useful for Japanese classic culture and there are many experimental discussions about Nanba walking. However, quantitative analysis of this walking pattern based on biomechanical data has not been inadequate. On the other hand, experimental study has been harder because of the difficult problem of facility. The purpose of this study are to generate Nanba walking by numerical simulation using three dimensional full human body simulation model as neuro-musculo-skeletal system including precise foot segment model developed in the past study and analyze the difference between Nanba walking and normal walking. As a result of simulation, Nanba walking was generated in order to change the feedback equation of neural oscillators. In simulation, walking characteristics such as locomotive speed and locomotive energy efficiency were optimized according to walking pattern respectively. As a conclusion of this study, it is validated as the effectiveness of Nanba walking that Nanba walking is suitable for faster locomotive speed because walking stability is also high in the single support phase by a little rotation of the upper body.

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We aim to clarify the mechanism of the release point of the golf swing and the effect of the acceleration pattern of the down swing on the dynamic behavior at the release point. We consider that uncocking begins naturally without driving torque applied to the wrist joint when the angular velocity of the arm and the centrifugal force become to be sufficiently large compared to the angular acceleration and tangential inertial force,. We derive simple approximate equations which express the relationship between angular velocity and acceleration at the release point. By using the derived equations and the acceleration pattern of the down swing, we develop calculation methods to estimate the effect of the acceleration pattern expressed by the polynomial of time on the dynamic behavior at the release point which may affect significantly on the head speed. We discuss how the patterns affect to the release point for two types of acceleration pattern which are expressed by the 1^st order function of time. Through the discussion, it can be seen that acceleration pattern which has positive gradient gives high angular velocity of the release point and later release point, and negative gradient pattern shows low angular velocity and earlier release point and these results can explain mechanism of so-called late hitting.

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We performed first-principles-based calculations of density of states, electrical conductivity, Seebeck coefficient, and thermal conductivity of a p-type half-Heusler compounds (ZrCoSb) to identify the alloy composition that gives rise to a high thermoelectric figure-of-merit. The strategy here is to substitute constituent atoms of ZrCoSb with lighter or heavier homologous element to reduce thermal conductivity without appreciably altering electrical properties. The density-of-states calculations reveal that substitution of Sb does not singnificantly alter the electronic states near Fermi level. The small influence on electrical properties was also confirmed by performing calculations for ZrCoBi, where the power factor is slightly larger than that of ZrCoSb. The effect of alloying on thermal conductivity reduction was quantified by equilibrium molecular dynamics simulations of ZrCoSb_1-xBi_x with force fields obtained from first principles. With increasing alloy fraction x, thermal conductivity rapidly reduces to less than 15% of that of ZrCoSb and nearly saturates above x～20%, suggesting ZrCoSb_0.8Bi_0.2 to be a reasonable alloy composition for high thermoelectric performance.

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The purpose of this research is the application of new design method for integrating the optimum strength evaluation and the product design which can make the best use of the composite material's characteristics obtained by the experiment and the analysis. Here, the collaboration of the design and the strength analysis by using composite materials is carried out. The products, which are made from high strength composite materials, need new product design technology which draws out the characteristic of material's advantage. Existing product developments tend to separate product design from product planning. The process consists of a certain flow, starting from planning the shape of the product by designers, then calculating the strength, and lastly designing the product. In the new design method, it is performed a styling design by requirements from the engineering point of view. By using this design method of high-strength materials, we designed new styling ZIGZAG Chair made of the carbon fiber reinforced plastic with excellent strength and lightweight. And then, analyzed it.

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In this study, we propose innovative polishing method for hard-to-process semiconductor substrate such as SiC. Our innovative polishing method mainly consists of 2 technologies. One is unprecedented polishing pad “Dilatancy pad” composed of special filler and viscoelastic material. The other is high speed/pressure processing technology with bowl feed method. We aim at high efficiency and high grade polishing of hard-to-process substrate by the fusion of these 2 technologies. In a SiC polishing, Dilatancy pad can realize removal rates more than 3 - 6 times in comparison with a conventional metal plate or nonwoven fabric pad. At the same time, the occurrence frequency of the processing damage (scratches, outbreak depth of polishing damaged layers) can be improved drastically in comparison with conventional method. It means that using Dilatancy pad in the middle processing of the substrate can lighten the load from the final polishing by reducing generation of polishing damage compare to conventional process. In our proposed high speed/pressure processing with bowl feed method, stable polishing performance can be achieved even though huge pressure such as 1000 kPa is applied. Where, much higher removal rate is obtained compare to conventional low speed/pressure processing. Using both technologies for SiC polishing, removal rate of 9.3 μm/hr and surface roughness Ra of less than 3nm are achieved. From these result, we have figured out to shorten the total processing time of substrate, middle processing and final processing, by our innovative polishing method.

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This research studied the effects of Zinc Dialkyldithiophosphate (ZnDTP) additives on the tribological properties of a H-free Diamond-like Carbon (DLC) film under boundary lubrication with oils that contained organic friction modifiers (FMs). The tribological properties were evaluated using the reciprocating type cylinder-on-disk tribo-tester. ZnDTP and three types of organic additives (GMO, glycerol mono-oleoyl ether (GME), and tallow diethanol amine (TDEA)) were added to poly-alpha olefin (PAO). Friction tests were carried out for the DLC/Steel tribo-pair under lubrication with PAO and PAO-based oils containing GMO, GME, TDEA, ZnDTP, GMO + ZnDTP, GME + ZnDTP, and TDEA + ZnDTP additives. Raman spectroscopy, Scanning Electron Microscopy (SEM), energy-dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS) were used for analyses of worn surface on the H-free DLC film. The H-free DLC film lubricated with PAO + FMs reached an ultralow friction coefficient of 0.02 - 0.03. On the other hand, The H-free DLC film lubricated with PAO + FMs + ZnDTP had increased friction coefficients compared to the PAO + FMs oils. For the lubrication added ZnDTP additive, the surface analyses demonstrated that the chemical composition of the ZnDTP-derived tribofilm depended on the combination of ZnDTP and each FM. It was concluded that the chemical composition of the ZnDTP-derived tribofilm played an important role in the friction behavior of the H-free DLC films that were lubricated with PAO + ZnDTP and PAO + FMs + ZnDTP.

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Many kinds of knee simulators have been developed. There are several concerns about the current simulators. First, the simulators for wear testing are driven using knee kinematics and loading profile data obtained from a normal gait. However, knee kinematics and knee joint forces are "the outcome" caused by muscular forces and external loads applied to the knee joint. As for the simulators for the kinetics and kinematics measurement of total knee arthroplasty (TKA), the knee is flexed in a "passive way" by applying constant muscular tension forces. This being so, simulators should be driven by muscular forces and external loads, i.e. in an "active way". Second, the effects of hip joint motion are not taken into account. Thirdly, the external load for example, upper body weight is not applied in a physiological way. Finally, few simulators are capable of knee flexion greater than about 100°. To this end, we have developed a novel knee simulator that has the following advantages and innovative features. First, it is driven directly by muscles' tension forces, thereby generating active flexion. Secondly, a hip joint is incorporated and the lower limb motion is achieved in a synergistic way between the hip and knee joints. Thirdly, it is capable to make a complete deep knee flexion.

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Distal radius bone fracture is major disease for elderly people. As its cure needs fixing the wrist for long time, the wrist often stiffens up and the range of its motion tends to be restricted, which is generally called “contracture”. As the contracture interferes with their daily life, the speedy improvement of the contracture are strongly required. Thus, the rehabilitation of the wrist joint is necessary. Recently, the traction of the maniphalanx during flexing and extending the wrist joint is considered to be efficient as the rehabilitation procedure. However, the recovering mechanism by the traction is not clear. The investigation of its mechanism will improve the rehabilitation procedure and be available for development of rehabilitation equipment. However adjusting the magnitude and direction of the traction force to the maniphalanx applied manually during such rehabilitation procedure is almost impossible. Thus, we developed a rehabilitation equipment for the investigation. The equipment mainly consists of a wrist traction device and a round-rail base. The wrist traction device can pull maniphalanx toward finger direction by constant weights, and slide roundly. Thus, the equipment can applied the constant traction force to the wrist during flexing and extending the wrist joint. By the equipment, the dynamic motion of carpals in the wrist is observed by X-ray photography. As a result, it is found that the displacement range of radius - lunate joint (R-L joint) is extended by the traction. Namely, if R-L joint suffers contracture highly, the discussed rehabilitation procedure well moves R-L joint and can improve its movability.

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The intracellular force transmission is critical for various biological events. It has recently been suggested that the cell nucleus is exposed to the mechanical forces transmitted through the cytoskeleton from outside the cell, and the changes in nuclear morphology possibly affect the regulation of cell functions. However, it remains unclear at this stage how much force is applied to the intracellular nucleus and how the morphology of the nucleus changes during cell contraction or release of intracellular tension. In the present study, we investigated the changes in the traction forces of the vascular smooth muscle cells (SMCs) cultured on polydimethylsiloxane-based elastic micropillar array substrates in the state of the contraction with actomyosin activation or the release of tension with F-actin disruption. We found that the total tension of SMCs increased from ~100 nN to ~200 nN following cell contraction, and decreased to less than 1/5 following F-actin disruption. We also measured the three-dimensional morphology of the nucleus of SMCs in the state of contraction or tension releasing using confocal microscopy. The nuclear height decreased significantly by ~10% following cell contraction, and dramatically increased by ~50% following F-actin disruption, indicating that the intracellular nuclei were compressed physiologically. Based on these mechanical and morphological data, we analyzed the force applied to the nucleus using a simple two-dimensional cell model, and estimated the compressive stiffness of the nucleus for the first time. Even though the nucleus has been believed to be the stiffest organelle, the estimated nuclear stiffness was in the range of 10 nN/μm in this study, indicating that the intracellular nucleus has a relatively large deformability similar to that of cytoplasm.

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For characterizing vehicle dynamic behavior, the natural frequency and the damping ratio under position control, that is the control using steering angle as driver's input, have been developed as representative indices. However, a driver believes that he/she is controlling the vehicle maneuvers not only by steering angular input but also by steering torque input, that is, force control. Thus, in order to improve vehicle dynamic behavior further, it would be essential to carry out an analysis of the effect of force control on the natural frequencies and the damping ratios. However unlike position control, those indices under force control have been formulized only for neutral steer vehicles with a specific condition. The reason for this is that the characteristic equation of the system under force control consists of a combination of the steering system and the vehicle system, which turns into a biquadratic equation about Laplace operator s. To solve this equation, this paper formulized those indices by an approximation using general vehicle specifications, with final confirmation that the approximation errors do not exceed 5%. Finally, an example of an improvement in the vehicle dynamic behavior was demonstrated by comparing the results of original settings and those of assumed settings. Based on this result, it is shown that the vehicle dynamic behavior could be identified by force control indices as well as position control indices.

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Image processing is one of the methods used to measure position/attitude for robot control and there are hopes that it can be applied to space robot missions, including REX-J (Robot EXperiment on ISS/JEM). The REX-J mission involves space robot locomotive function experiments using tethers by JAXA. Measuring the robot's motion accurately is crucial to establishing the new locomotive technology using tethers. With conventional methods, a suitable illumination environment is configured for high-precision image processing and a characteristic marker is attached to the measurement object. However, the two challenges posed for image processing during the REX-J mission are: (1) the illumination of space changes significantly with orbital motion and (2) the robot lacks a characteristic marker. Accordingly, our purpose is to develop a marker less image processing method for the illumination environment of space and measure the robot's position/attitude of the REX-J mission by image processing. The proposed new image processing method involves creating virtual points are created at the intersection of the robot's edge in the image, which are then used as markers for image processing. This method is robust for changes in the illumination environment because it allows the creation of a virtual point, even if the edge is incomplete. The method is applied to the REX-J mission and the measurement accuracy of the robot's position/attitude in the illumination environment of space was confirmed as on the sub-pixel level. Subsequently, the position/attitude of the robot during movement by tethers was measured by image processing. In addition, the error in the robot's position/attitude, as estimated from the length of the tethers, was clarified by the image processing result. Based on these results, the robot's locomotive function by the REX-J mission was verified.

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