自動車のしゅう動部品材料は, 高性能化, 低燃費化, 低公害化のため, 今後ますます過酷な条件で使用される.しゅう動部品材料の開発とあわせて, 設計技術, 生産技術の向上が不可欠である.
自動車用しゅう動部品材料のトライボロジーについて, 各要素ごとに概要を述べたが, 紙面の都合上, 断片的な情報しか提供できなかった.自動車のトライボロジーに興味をもっていただくきっかけになれぼ幸いである.

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This paper describes an approach for estimating motion parameters of a rigid body utilizing three-dimensional (3-D) correspondence. 3-D positional information of object feature points, which is available for object representation and robot vision, is extracted by stereo matching at each instant. The correspondence between two 3-D point sets at sequential time instances is needed to find motion parameters, the best one is established using Hopfield neural network. On the basis of acquired information, two methods for motion estimation are proposed (1) in an incremental manner under a condition for smoothness of motion, and (2) in an iterative operation according to a Daugman-type linear network architecture. The results of applying these schema to a sequence of stereo images are presented.

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This development paper describes the optical measurement system of diametral dimension by parallel scanning of a laser beam. The measure is taken by counting the synchronous pulses with the scanning position of the beam. The pulse signal is generated with a linear scale composed of the optical slits at an equal space on the rotational scanning unit. Therefore a high-precision constant speed motor and fundamental optical components such as a scanning polygon mirror and an Fθ lens fall into disuse. Its compact size and omission of complicated electronic circuits for time-consuming calculation are also strong points of the developed measurement system.

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This paper deals with an integrated modeling system of machine tools for dynamic analysis and simulation. The structural elements of the machine tools are represented by a set of primitives with information about finite element meshes. An algorithm is newly proposed based on a concept called CBC (Coded Box Cell) substitution approach to match the finite element meshes at the interface of primitives with relative movements. The nodes on the boundary surfaces between the two adjacent primitives are automatically adjusted by referring to the information of the vertex label and the face label of the meshes. The results of case study show that the finite element model is adjusted dynamically and locally at the boundary of the table and the slider which is fed on the table. It is expected that the method proposed is quite effective to analyze the structural characteristics of machine tools under the moving conditions.

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データ変換プロセスを定式化し, STEP規格を正確に実現しているCADデータ交換システムの構成法を導いた.
STEPデータとCADデータの集合, およびそれらの間の関数関係として定式化したデータ交換プロセスの機能モジュールをCADデータ交換システムの仕様に対応づけた.CADデータ交換システムの仕様は, STEPのデータ記述言語EXPRESSで記述することとし, 交換対象とするSTEPデータを規定するSTEPアプリケーションプロトコル, CADデータモデルのデータ構造記述とデータに関する拘束条件, およびCADデータとSTEPデータとの変換関数の組として与える.EXPRESS処理プログラムはこのデータ交換システムの仕様を翻訳し, 共通的に用意するプログラムおよびCADシステムごとに用意するプログラムと組み合わせてCADデータ交換システムを構成する.
本文に従って構成されるCADデータ交換システムは, CADデータ交換システムの仕様の定義がデータ変換の形式的な定式化に従っていてSTEP規格文書を正確に実装していることが検証可能となっている, STEP規格のEXPRESS言語を主たるシステム仕様記述言語として利用することでSTEP規格との対応付けが正確で容易であるなどの特徴を有する.
本文で提案した定式化に従うCADデータ交換システムを試作しており, Brepソリッドモデルの交換実験を行って有用性を確認している⁸⁾ .

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On the problem of robot path planning using a configuration space approach, since boundaries of obstacles in the configuration space are very complex, it is difficult to construct those boundaries by analytic methods. Therefore, most of the approach to find a safe path are using search strategies, for examples, the configuration space is devided into cells and interferences are checked in each cell. But for those search strategies, it is difficult to determine the existence of the safe paths. This paper describes the method that represents the obstacles as a CSG/B-Reps dual solid model in the configuration space, by deriving the boundaries of obstacles in the configuration space in an analytical way. Using that solid model, an existence of the safe paths is determined, and if so, one of the safe paths is also generated.

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In creep feed grinding, the grinding cracks are generated by heat. It has been known by experience that the grinding fluids influence on grinding cracks. Grinding fluids are generally used for cooling and lubrication. To evaluate the properties of grinding fluids, the temperature at the grinding point, cooling rate of work material and load carrying capacity of grinding fluids were checked. Finally it was clarified that a gentle slope of cooling could relieve the grinding cracks and high load carrying capacity of grinding fluid was not effective.

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In belt grinding, the amount of heat generated throughout the grinding process is basically less compared with that of the grinding wheel. However, when heavy grinding conditions are selected for obtaining high machining efficiency, the flatness error of the belt machined surface gets considerably larger than under normal conditions because of the high level of heat generation. Therefore, for reducing this flatness error, the depth of cut of the abrasive belt calculated by fuzzy inference was applied to the workpiece surface. In order to do this, the trace curves of abrasive belt on the workpiece surface were calculated by using fuzzy inference, rules of which were decided from simple models based on the basic grinding experiments. As a result, the accuracy of machined surfaces were improved significantly, and the propriety of applying this method for belt grinding was confirmed.

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減圧下チャンバ内でのガス燃焼法 (減圧チャンバフレーム法) の欠点である真空系をなくした大気圧下チャンバ内での燃焼炎法 (常圧チャンバフレーム法) を提案し, 同方法はチャンバを用いない大気圧下での燃焼炎法 (従来法) に比べて不純物元素の混入が少なくかつ凹凸の少ない良質なダイヤモンド膜を提供できることを実証した.また常圧チャンバ法において, クラスタダイヤモンドによる基板処理の手法と合成条件を段階的に変化させる手法を組み合わせて採用することにより結晶の微細化が図れることを示した.最後に両手法により得られたコーテッドダイヤモンド切削チップの性能評価を行った結果, 常圧チャンバフレーム法により作成した切削チップは耐久性能及び被加工材の仕上面性能において熱フィラメントCVD法による切削チップとほぼ同等の性能を有することを明らかにした.

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Automatic monitoring of cutting process is one of the most important technologies for increasing the stability and the reliability of unmanned manufacturing system. In this study, the methods which use acoustic emission (AE) signals are proposed to monitor chatter vibration, tool wear and cutting edge breakage in the milling process. All experiments were conducted on an NC-vertical milling machine. The ball endmill cutter with 2 cutting edges and the square endmill cutter with 4 cutting edges were used. Using these equipment, the single-sensor monitoring system was constructed.

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In grinding operations, one of the most important problems is to determine the tool life of a grinding wheel accurately. Frequent dressing wastes not only time but also the abrasive materials, which becomes crucial when an expensive tool such as a CBN wheel is used. Grinding with a worn wheel causes the workpiece surface roughness to increase and often results in the occurrence of such troubles as chatter vibration. However, highly reliable techniques to monitor the tool life of a grinding wheel have not been established yet, and the wheel life is, in most cases, determined by human operators based on their observations and expertise. In this study, the monitoring method using an acoustic emission (AE) sensor is proposed to define the wheel tool life in the cylindrical grinding process. The contact detection between the wheel and the dresser, as well as the evaluation of the grain sharpness, are attained by monitoring the amplitude level of the AE signal. The chatter vibration is, on the other hand, detected by observing the power spectrum of the rectified AE signal, and well recognized by means of the neural network.

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This paper deals with the lapping characteristics for crystallographic orientation of single crystal diamond. The rough diamonds were lapped by cast iron lap as well as steel lap and diamond wheels. The lapping removal depth, lapping force ratio (tangential force / normal force) and lapping temperature for lapping direction on the typical three planes were measured. Experimental results are as follows : the relationship between lapping removal depth and lapping force ratio was devided into the following two trend. In the lapping by cast iron lap and steel lap, at the easy lapping direction (i.e. {110}, <100>) lapping force ratio was small and lapping temperature was low, at the hard lapping direction ({110}, <110>) the former value was large and the latter was high respectively. On the other hand, in the lapping by diamond wheel, at the easy and hard lapping direction these two values changed conversely in the tendency of the cases by cast iron and steel lap.

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This paper describes the relation between the right angle error and the accuracy of a convex spherical shape on works when using lip type grinding wheels. The right angle error between a work axis and an inner cone surface of a lip type grinding wheel brings the effect upon the spherical shape on the work, and deforms its shape to aspherical. The expressions of this aspherical shape are formulated, and the correlative equations between the right angle error values and the patterns obtained from interference fringes of this aspherical shape are also made out. The experiment is performed for the optical glass rod work (φ10×L100mm) using a lip type grinding wheel filled up with 7 μm diamonds. Following conclusions are obtained : (1) When a work axis and an inner cone surface of a lip type grinding wheel are not at right angles to each other, the spherical shape obtained on the work deforms to aspherical having a cone shape at the center, and having other spherical shape (its center is not on the work axis) at the peripheral part of the surface of revolution. (2) As a work axis inclines toward the opened side of a grinding wheel and its value Δγ is 7.0×10^-3 rad, the peak shape is formed at the center and about 16 pieces of interference fringe appear on the work in agreement with the calculated results on the experiment.

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(1) TiB₂導電性ファインセラミックスは, ワイヤ放電加工では強度低下が非常に小さい.
(2) 標準タイプTiB₂は, 高いデューティファクタでも強度低下は小さい.クラックが存在しても著しく浅いため, 強度低下は少ない.
(3) 高硬度タイプTiB₂は, 型彫放電加工による50%のデュティーファクタで55%程度の強度低下を示すが, 硝酸によるエッチング法で50μm除去すれば著しく強度回復する.この方法は形状の制約がない点からも有効と考える.
(4) 同様に形状の制約の無い硝酸ソーダ水溶液による電解加工を試み, 5A/cm²の電流密度で2min程度の加工でクラックが消失する.仕上面粗さはパルス電流が有利と考える.
(5) 型彫放電加工による50%のデューティファクタにおいて通常は深いクラックを発生する条件下においても粉体混入放電加工法を使用すれば単発放電による浅いクラックと大差ない結果が得られた.従って, 高いデューティファクタで放電加工を行う場合は, 粉体混入方式を使用すれば著しい強度低下を防ぐ可能性があると考える.
(6) 通常の放電加工によるデューティファクタが高い電気条件で深いクラックが発生した場合は, エッチング法及び電解加工によって強度回復が可能である.

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Fast and fine position control of an ultrasonic motor is generally difficult because its rotational speed is nonlinear to voltage, frequency or phase shift input. This paper shows both theoretically and experimentally that the motor has an approximate first-order transfer function between phase shift input and rotational speed output in the case of coarse motion to a command position. This paper also shows experimentally that the rotor moves finely and intermittently in the neighborhood of the command position. A linear position control system which applies integral control action was developed. A fast response of about 50ms and fairly high positioning accuracy up to a rotary encoder resolution were both realized.

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A coordinate measurement method is developed which is based on optical triangulation and uses a spherical mirror as a target. Each of the three axes employs a slit-ray laser scanner and a photo-detector to detect the direction of the regular reflection from the target mirror. Since this method detects only the center of curvature of the mirror, it is suitable when the attitude of the target changes, e.g. a robot arm. Moreover, the use of the spherical mirror allows precise calibration and easy set up. To demonstrate this measurement method, coordinate values in one-dimension were measured at various distances. In this paper, the results form this one dimensional test are presented. The proposed measurement method was shown to be feasible through this experiment. The small beam size and small divergent angle of the light source produced high accuracy, while the detector size was found to have little effect on the accuracy. The measuring accuracy of the system was evaluated to be 20 μm at a distance of 750 mm.

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Fringe counting techniques are often used in modern laser interferometers for measuring displacement. These interferometers are essentially integrating devices, where the displacement is derived from an accumulated fringe count, that is, they measure travel rather than static displacement. If the interferometer optical paths are interruptedduring a measurement cycle, the reference for the instrument is lost and accuracy suffers. In this paper, a holographic technique whereby displacement is measured by analyzing a fringe pattern localized at infinity which is equivalent to Haidinger or Brewster fringes in conventional interferometry is described. The phase distribution of the fringe pattern is measured to high accurcy using phase-stepping interferometry, and then analyzed by computer. Using this technique, in-plane displacements could be measured with an accurancy of about 0.2μm whilst the accuracy for out of plane displacements was about 2μm.

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This paper presents a new method to feed a table smoothly over a long stroke by utilizing deformation of piezoelectric elements, which is named “Walking Drive.” The principle of the method developed is similar to walking motion of animals such as human beings, dogs, spiders, centipedes and so on. The table is fed smoothly over a long stroke with the combinations of clamping and feeding motions of piezoelectric actuators controlled in synchronization despite the fact that the stroke of each piezoelectric element is limited. A precision feed system based on the walking drive was developed using a ceramic air slide, and the feasibility of the drive mechanism was confirmed.

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