During the boring process of the engine cylinder liner in automotive manufacturing, the heat at the cutting point flows into the cylinder liner and causes it to thermally expand, which is an inescapable machining issue. This affects the machining accuracy of the machined liner. However, the thermal expansion can be minimized under suitable cutting conditions and boring operations. The boring operation of an engine cylinder liner usually has two stages, semi-finishing boring and finishing. Different from the conventional boring operation, a new boring operation which can perform semi-finishing boring and finishing boring in one stage is explored in this paper. By this boring operation, the influence of the thermal expansion of the machined liner can be minimized. This boring operation is called a “simultaneous boring operation” in this paper. To prove the validity of the simultaneous boring operation, a finite element method (FEM) model was developed to predict the thermal behavior in the cylinder liner during the simultaneous boring operation/conventional boring operation. The results show that the machining errors caused by the thermal expansion of the cylinder liner during the simultaneous boring operation are smaller than those of the cylinder liner during the conventional boring operation. To investigate the influence of the cutting conditions on temperature distribution in the cylinder liner during simultaneous boring operation, FEM analysis of the temperature and thermal expansion on the cylinder liner under three levels of cutting speeds (300,600, and 900m/min) combined with two types of cutting fluid (dry, wet) during simultaneous boring was performed. The results showed that the temperature rise of the cylinder liner during a high-speed, wet simultaneous boring operation is small.

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This paper derived the surface profile equations and the meshing equations of the spherical meshing elements from the homogeneous coordinate transformation matrix and the conjugate surface theory proved by the envelope theory. In the machining aspect, we demonstrated the position equation of cam profile using the coordinate transformation theory and obtained the perfected controlling position point of the tool path under the limitation of the chord errors. Finally, the design and the machining module was developed via Visual Basic that generated the cam profile points and the tool path points. The curves from UNIGRAPHICS to test and verify the cam profile equation. To verify the validation of the tool path, a cutting simulation software, VERICUT, is used to simulate the cutting geometry and kinematics of the roller gear cam, and demonstrate the practical application of the developed method.

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A new type of compliant foil bearing (CFB)-Aerodynamic Foil Journal Bearing with Elastic Support was developed and analyzed in this paper. Sets of physical models were proposed to solve the Elastohydrodynamic (EHD) coupling problem for this new type of CFB. The characteristics of compliant foil supported by elastic foundation were studied. The transient compressible Reynolds' equation was adopted while considering the nonlinear dynamic force of the gas film. The theoretical methods of obtaining the static and dynamic parameters of the bearing-rotor system were deduced. Finite Element Method (FEM) was used in order to solve the elastic foundation deformation and CFB's governing equations.

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Recently, wheel separation accidents in such vehicles as trucks, buses and passenger cars have drawn a social concern. Explications of their causes and adequate practices of countermeasures for them have been urgently required. In relation to this issue, the authors have taken notice of subjects which are concerned in bolted joints at wheels and are especially trying to study the pressure distribution at the bearing surface of nuts. This report deals with the subject of a nut with a cone-form bearing surface. Considerations are based on numerical results derived from finite-element-analysis. Feature of the pressure distribution by this profile and influences from geometrical deviations of the form are mainly discussed, and some other information concerning this issue is presented.

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This paper presents an in-process status monitoring method for ultraprecision machining system and an adaptive control system equipped with the function. The crux of this method is an effective in-process micro sensor which can detect physical behavior around the cutting point during ultraprecision machining process. In this study, we develop a micro-miniaturized platinum resistance thermometry-type sensor with micro-fabrication process and then mount it on the rake surface of a single diamond tool tip nearby the cutting point. Through a series of cutting experiments with an ultraprecision diamond turning machine, we evaluate the developed sensor. As a result, experimental results confirm that the developed sensor has useful characteristics such as high sensitivity, compactness and quick response. In addition, we realize an adaptive control system for ulatraprecision machining process. The developed system maintains a constant temperature around the cutting point by controlling the cutting speed. Adaptive control experiment results confirm the developed system has high potential for detecting small thermal and small dynamic behavior of the cutting point during ultraprecision machining process.

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It is well known that the total machining errors of the engine cylinder liner are mainly dominated by the elastic deformation caused by the cutting force and the thermal expansion caused by the temperature rise during the boring process. Clarification of the amount of machining errors resulting from the cutting force and thermal expansion is useful for determining whether thermal expansion or the cutting force has a larger influence on machining errors during the boring process. This would provide a clear approach to the optimization of cutting conditions or to product improvement, leading to a higher degree of machining accuracy. In this paper, in order to clarify the amount of machining errors, the machining error caused by the thermal expansion apart from the elastic deformation of a cylinder liner caused by the cutting force was first determined. For this purpose, an experimental method is suggested in this paper. The temperature rise that causes the thermal expansion of the cylinder liner was simulated by a YAG laser heating process instead of by an actual boring process. During this heating process, the machining errors caused by the thermal expansion could be solely investigated. First, an actual cylinder boring process was performed (cutting speed: 900 m/min, feed rate: 0.2 mm/rev, depth of cut: 0.3 mm, dry cutting). The total machining errors caused by the cutting force and thermal expansion were measured. Then, the YAG laser heating experiment was also carried out. Comparing the results between the two experiments, it was clarified that the thermal expansion of the cylinder liner caused by the cutting energy is dominant and the deflection caused by the cutting force is small.

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A compact centrifugal blood pump consisting of a controlled two-degrees-of-freedom radial magnetic bearing and a brushless DC motor enclosed in a titanium housing has been developed for use as an implantable ventricular assist device. The magnetic bearing also supports axial and angular motions of the impeller via a magnetic coupling. The top housing is made of pure titanium, while the impeller and the stator are coated with pure titanium and Ti-6Al-7Nb, respectively, to improve the biocompatibility of the pump. The combination of pure titanium and titanium alloy was chosen because of the sensitivity of eddy current type displacement sensors through the intervening conducting wall. The dimensions of the pump are 69.0 mm in diameter and 28.5 mm in height. During a pump performance test, axial shifting of the impeller due to hydraulic forces led to variations in the rotational positioning signal, causing loss of control of the rotational speed. This problem was solved by conditioning the rotational positioning signal. With a flow rate of 5 l/min against a head pressure of 100 mmHg, the power consumption and efficiency of the pump were 5.5 W and 20%, respectively. Furthermore, the hemolysis of the blood pump was 43.6% lower when compared to that of a commercially available pump.

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Demands for three-dimensional nano-positioning are increasing in a wide range of industries. In order to meet such demands, it is necessary to realize a stable long-stroke vertical nano-motion. In long-stroke vertical motion control, the minimization of gravity load is one of the most important issues. In addition, it is important to minimize error factor from nonlinear phenomenon such as friction, vibration and heat transfer. In general, however, it is difficult to support gravity load of the moving part and to ensure that the vertical motion platform is free from such error factors which may occur during its nano-positioning. In this study, therefore, a novel vertical motion platform with a noncontact counterbalancing mechanism is developed for achieving long-stroke vertical nano-motion. The developed platform is characterized by a noncontact drive with a voice coil motor, by levitation with aerostatic guideways, by a counterbalance with noncontact vacuum cylinders, by an overall structure made of ceramics and by a symmetrical structural configuration. The positioning performance of the developed platform is evaluated through a series of vertical positioning experiments. The experimental results demonstrate that the developed platform has a superior positioning performance.

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In order to realize the intelligent machine tools, which can autonomously determine the cutting states and can change them automatically as required due to changes in the environmental conditions, an in-process monitoring and identification of cutting states is developed for CNC turning machine to check and improve the stability of the processes. The method developed utilizes the power spectrum density, or PSD of dynamic cutting force measured during cutting. Experimental results suggested that there are basically three types of patterns of PSD when the cutting states are the continuous chip formation, the broken chip formation, and the chatter. The broken chip formation is desired in order to realize safe and reliable machining. The proposed method introduces three ratios, which are calculated from three dynamic cutting force components and obtained by taking the ratio of cumulative power spectrum density for a certain frequency range corresponding to the states of cutting to that of the whole frequency range of each dynamic cutting force component, to classify the cutting states of continuous chip formation, broken chip formation, and chatter. The algorithm was developed to calculate the values of three ratios during the process in order to obtain the proper threshold values for classification of the cutting states. The method developed has been proved by series of cutting experiments that the states of cutting are well identified regardless of the cutting conditions. The broken chips are easily obtained by changing the cutting conditions during the processes referring to the algorithm developed.

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In this paper, we consider the problem of lens distortion adjustment of semiconductor lithography equipment. The objective of adjustment is to minimize the maximum absolute value of distortion. Formerly, an approximate solution method based on the least-squares method has been used. Recently, an approximate solution method based on iterative least-squares method with weight was proposed. However, calculation of that method often takes long time and a better calculation method has been desired. In this paper, we propose an exact solution method based on LP (Linear Programming) to minimize the maximum absolute value of distortion. Now, LP solvers find an optimal solution very fast owing to the progress in linear programming research. Consequently, optimal solutions for 20 instances obtained by our method provided adjustment parameter settings about 29% from 27% better than that by the solution method based on the least-squares method.

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This paper deals with the grinding characteristics of newly developed ultrafine-crystalline cBN (cBN-U) abrasive grains in creep feed profile grinding of high-speed steels. Experiments for producing a V-shaped groove on a flat surface in one pass by creep feed grinding have been carried out using new polycrystalline cBN-U and representative conventional cBN (cBN-B) abrasive grains. When grinding with the cBN-U wheel, both radial wear and profile wear are less, and hence the grinding ratio is around 4 times higher than that with conventional cBN-B wheel. Grinding force in grinding with the cBN-U wheel is reduced by 5∼15 % compared with that in grinding with the cBN-B wheel. The cBN-U abrasive grain is suitable for application with a high dimensional accuracy in creep feed profile grinding for high-speed steel, because it gives less profile wear, and hence better form retention of the wheel, than conventional cBN abrasive grain.

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Data mining is an important facet of solving multi-objective optimization problem. Because it is one of the effective manner to discover the design knowledge in the multi-objective optimization problem which obtains large data. In the present study, data mining has been performed for a large-scale and real-world multidisciplinary design optimization (MDO) to provide knowledge regarding the design space. The MDO among aerodynamics, structures, and aeroelasticity of the regional-jet wing was carried out using high-fidelity evaluation models on the adaptive range multi-objective genetic algorithm. As a result, nine non-dominated solutions were generated and used for tradeoff analysis among three objectives. All solutions evaluated during the evolution were analyzed for the tradeoffs and influence of design variables using a self-organizing map to extract key features of the design space. Although the MDO results showed the inverted gull-wings as non-dominated solutions, one of the key features found by data mining was the non-gull wing geometry. When this knowledge was applied to one optimum solution, the resulting design was found to have better performance compared with the original geometry designed in the conventional manner.

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In motion generation, the objective is to calculate the mechanism parameters required to achieve or approximate a set of prescribed rigid-body positions. This work introduces a new design constraint that considers driving link static torque for a given rigid-body load. By incorporating this new constraint into a conventional planar five-bar motion generation model, planar five-bar mechanisms are synthesized to not only achieve prescribed rigid-body positions, but also satisfy maximum driver torque for a given rigid-body load.

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A new heuristic method called Topology Mining (TM) is proposed for topology optimization of framed structures, where the problem is formulated as 0-1 mixed-integer optimization problem. TM uses the apriori algorithm, developed in the field of data mining, to efficiently extract the bar sets that frequently appears among superior solutions, and proceeds so as to preserve the sets. Hence, the process of optimization can be investigated by tracing the frequent bar sets, accordingly, the parameters for optimization can easily be adjusted. It is pointed out that the ground structure method based on nonlinear programming is not effective for finding optimal placement of braces for a given frame under local buckling constraints. We propose an integrated approach to obtain an accurate solution of this problem, where optimal placement of braces is searched by TM, and the sizing optimization is performed by nonlinear programming. Three numerical examples are solved to demonstrate the performance of TM in comparison with another heuristic method called tabu search.

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The rhythm of automatic cyclic movements such as walking is known to be generated by a rhythm generator called CPG in the spinal cord. The measurement of rhythm characteristics in walking is considered to be important for analyzing human bipedal walking and adaptive walking on irregular terrain. In particular, the soles that contact the terrain surface perform flexible movements similar to the movement of the fins of a lungfish, which is considered to be the predecessor of land animals. The sole movements are believed to be a basic movement acquired during prehistoric times. The detailed rhythm pattern of sole motion is considered to be important. We developed a method for measuring electrification without installing device on a subject's body and footwear for stabilizing the electrification of the human body. We measured the rhythm pattern of 20 subjects including 4 infants when walking by using this system and the corresponding equipment. Therefore, we confirmed the commonality of the correlative rhythm patterns of 20 subjects. Further, with regard to an individual subject, the reproducibility of a rhythm pattern with strong correlation coefficient > 0.93 ± 0.5 (mean ± SD) concerning rhythms of trials that are differently conducted on adult subjects could be confirmed.

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Mura defects in LCM panel of TFT-LCD have the properties of local low contrast and luminance variation without a clear contour on a uniformly produced surface. This research proposes two methods which are discrete cosine transform (DCT) and discrete wavelet transform (DWT). These methods successfully detect simulated blob-mura and real mura defects. DWT method is based on symmetrical 9/7 tap Daubechies coefficients that is superior for filtering the regular structure of color filter and small area defects. DCT method is better for detecting luminance variation in large area and poor for small ones.

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The CT (Computed tomography) method is very effective for making thinner optical waveguide-type tactile sensors. In a previous paper, the authors established the architecture of a CT tactile sensor and evaluated its principle using a series of computer simulations. As a result, the LU decomposition method showed better noise robustness compared to the ART method. On the basis of the simulations, we develop an experimental CT tactile sensor comprised of infrared diodes, phototransistors, an acrylic plate and a black rubber sheet. In the present study, the LU decomposition method is employed and we determine the validity of the algorithm by examining use of a loading machine produced for the CT tactile sensor. In a series of experiments, it is found that absorption of light intensity increases monotonically with increase of applied force and that the present reconstruction method can be applied to not only simply but also multiply connected contact domains. The estimated position of the pressure centroid possesses a rather large error of 4.9 mm, which is 10.8% of a segment of the sensing area.

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