This paper deals with a new method for structural synthesis of mechanisms in a conceptual design as follows: first, using the Lie algebra-based representation of constraint on degrees of freedom, the authors propose an analysis procedure of the degrees of freedom between components in mechanisms of mechanical products. Second, this analysis procedure makes it possible to propose a structural synthesis procedure. Third, in order to select one of the mechanisms generated by the synthesis procedure, the authors introduce the concept of manipulatability as a criterion for the evaluation. Finally, to evaluate the usefulness of the proposed method, it is applied to an example of structural synthesis.

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As a basis for treating geometrical similarities of 3-D objects, an idea of a new data structure called "two layer structure with convex components" for representing polyhedra is presented. The two layer structure, which can be constructed uniquely for a polyhedron, consists of convex components separated into two layers, i.e., the first layer includes only positive convex components to be added and the second layer represents negative convex components to be subtracted from positive ones. The procedure for constructing the two layer structure consists of the following two processes. (1) Forward process: A concave polyhedron is decomposed and represented as a hierarchical tree structure with convex components. (2) Backward process: Components belonging to leaf nodes of the tree structure are put into the two layer structure according to the level of the node. The components are removed from the original polyhedron after processing each leaf node of the tree structure. These procedures are repeated to the modified object until the processes reach to the root node. The two layer structure can be applied for extracting features of polyhedra such as protrusions, holes and pockets, and comparing 3-D objects.

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An adaptive multirobot scheduling system was studied in order to introduce intelligent robots in a plant and to maintain the plant effectively. Necessary information for the plat maintenance tasks was classified by character that are a variable and a fixed information. In order to assign maintenance tasks to the robots, the scheduling system uses the fixed information of own databases, and gathers the variable information from the robots and a human operator adaptively. From numerical experiments it has been confirmed that the adaptive scheduling system could perform its original idea of adjusting the scheduling of maintenance operation even when an accident occurred in the plant or when a robot was disabled.

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Liquid crystal displays are commonly used recently, but productivity is not so satisfactorily high due to the occurrence of the uneven areas of brightness. Based on our empirical study, these uneven areas are believed to he caused by one of the most important processes, called rubbing process for liquid crystal display production. It was shown that fluctuation of frictional energy is the main reason for the occurrence of uneven display of brightness and elucidated the correlation between fluctuation of frictional energy and uneven display of brightness. In this research it was shown that fluctuation of frictional energy causes fluctuation of pretilt angle of liquid crystal molecule on the polyimide surface, and this fluctuation of pretilt angle on the surface causes fluctuation of brightness in liquid crystal display.

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They have developed a non-contact, high-speed, and multipurpose solder-joint inspection method using an electro-optic (EO) probe for fine-pitch LSI-packages on printed wiring boards. The EO probe was used to detect the electric field intensity above two adjoining leads of a LSI-package with no damage. They also developed a solenoid-actuator probe that could supply alternating voltages to the lead-pad on the board at high-speed motion. By scanning the two probes mechanically at a constant velocity and by actuating the solenoid-actuator at a constant frequency above each side of the LSI-package, they could achieve a high-speed inspection. And by applying this method to a QFP package that has a 0.5-mm pitch, they succeeded in locating the open and short failures at a scanning speed of 50-pin-per-second.

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This paper presents an evolutionary algorithm for the robust vibration suppression controller design in mechatronics systems, using a Genetic Algorithm (GA). The control system is composed of a robust 2-degrees-of-freedom (2DOF) compensator based on the coprime factorization description. In the research, an on-site autonomous algorithm for the compensator design is proposed, where the optimal combination of the compensator free parameters can be tuned by the genetic process so that the real plant output should coincide with the reference one which satisfies the specified control performance. The effectiveness of the proposed optimal design has been verified by experiments using a prototype, paying attention to the system robustness against variations of mechanical parameters.

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This paper presents the inertia identification method in which the factors of viscous friction, Coulomb friction and constant disturbance torque are eliminated. It has a model of a velocity controller and rigid mechanical system integrating faur conditions described as follows. The first condition is that real velocity equals model velocity and is not zero. Under this condition, the inertia is calculated by taking the ratio of the integrated value of real torque reference in specified time range to the integrated value of the model torque. The second condition, elimination of viscous friction, is that the integrated value of velocity equals to zero in the specified time range. The third condition, elimination of Coulomb friction, is that the time range for velocity in positive direction equals the time range for velocity in negative direction. The last condition, elimination of constant disturbance torque requires selection of velocity references Vref1 which is satisfied with conditions 1 to 3 and Vref2 which is defined as inverting of Vref1. Then, the average inertia value under each velocity reference is computed. The experimentalresults using the one-axis stage verified the exact inertia identification.

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This paper describes a newly developed forward kinematic calibration method for parallel mechanisms which identifies the kinematic parameters using the pose data measured by a Double Ball Bar (DBB) system. The parameter identification procedure using forward kinematics does not require full pose data and, therefore, can make the measurement procedure simple. The measurement using the DBB system allows for large traveling plate orientations and enables simple and precise calibration. The principle of this method is first described, then the validity of this method is presented through simulations and experiments performed on a parallel mechanism based milling machine, named HexaM.

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This paper proposes a new method to recognize 3-D objects and their poses using the approximate representation of an image based on the 2-D orthogonal expansion by marginal eigenvecters of column- and row- covariance matrices. The proposed method considers 2-D structure of images, and executes learning process by treating low dimensional matrices, so it can learn a number of images with small computation cost compared with the methods based on the K-L expansion. The method can also recognize any pose of an object, which is not learned, using smooth interpolation between highly correlated discrete images obtained in learning stage of the object. In this paper, the learning and descriminating procedures are formulated and effectiveness of the method is shown through fundamental experiments with real objects.

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Reversal Method (RM) is a well-known method for straightness and roundness measurements. Although this method is very simple in principle, it requires the reversion of the test piece relative to the measurement reference. Such a reversion becomes serious problems in practical application because of operability and accuracy. Authors propose an improved reversal method (IRM) for straightness measurement. In this method, one triangular prism is used as reference piece and is rotated through 180°instead of the test piece. The edge of the triangular prism is measured with one laser sizer, in conjunction with a measurement of surface of test piece by one displacement sensor. The reversion becomes simple and its error can be reduced in this way. In this paper the effectiveness of IRM was discussed theoretically and experimentally as compared with RM. According to the experimental results, both methods are about the same measuring accuracy. Therefore, it became clear that the IRM could be applied for on-machine measurement.

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This paper presents a controller structure for a fast and precise fine positioner which can be attached to the end-effector of a classical industrial robot for assembly tasks. The overall control system consists of three elements: a position loop feedback controller, a feedforward controller, and a disturbance observer for the position loop. A useful method for compensating for the asymmetry and non-linearities of the piezoelectric based system is used as the first step in the design process. The robust feedback controller based on the disturbance observer compensates for external disturbances mainly from the coarse positioner. Precise tracking is achieved by the feedforward controller. Experimental results are presented to demonstrate performance improvement obtained by each element in the proposed robust structure.

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Mixture of epoxy resin and asphalt was used as sealant, which existed between the gasket and anode can, in the silver oxide battery. Best mixing ratio among epoxy resin, hardener and asphalt was proposed, and two reasons that the mixture of epoxy resin and asphalt show good seal characteristics are shown in this experiment. One of the reasons is that the mixture worked as soft material between gasket and can to decrease the clearances. Another reason is that the creep of alkaline on copper surface is decreased by the effect of epoxy resin. It has been proven that the mixture of epoxy resin and asphalt has good characteristics for sealing alkaline electrolyte by the mass production batteries. Absorbing the diphenylcarbazide to anode can copper surface brought out good seal characteristics for the silver oxide batteries. In conclusion, the mechanism of leakage of the silver oxide battery is that the electrolyte invades into clearances between the seal consisted by gasket and anode can and it generated hydrogen gas on copper surface, which made gas hall and leak path. It has also been proven that decreasing hydrogen gas generation is one of the most important ways to get better sealing.

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New surface structure with regular patterning for the frictional surfaces of the artificial joints was designed to improve the wear problems. The lubrication properties for the cup ( ultrahigh molecular weight polyethylene, UHMWPE) vs. ball ( Co-Cr alloy) were studied to evaluate the wear and surface roughness. The surface structure is the dents pattern which has diameter of 0.5mm, pitch of 1.2mm. In this study, such surface patterns were applied to artificial hip joints, and the effects of regular patterning on the frictional surface were investigated by using a joint simulator. The amount of wear of the cup that was in contact with the patterned head was only half that of the cup that was in contact with the non-patterned head, and the surface roughness of the cup with a non-patterned head was three-times greater than that of the cup with a patterned head. These results demonstrates that the lubrication properties can be improved by patterning of the frictional surface of the artificial joint. Consequently, the life of the artificial joint can be extended by the patterning on the frictional surfaces.

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Natural product cutting, especially deboning process of meat processing is a very difficult problem for machines or robots. This difficulty is caused by the softness, complex heterogeneous structure and undefined shape of meat. Therefore, the development of the special cutting device for deboning machine is very important to realize the process automation. In this study, a kind of intelligent cutter for robot deboning was developed. The feature of it is to separate the functions of cutting and positioning the cutter. The basic structure of this intelligent cutter is as follows. Guide plate is attached parallel to the knife blade. Knife blade is usually hidden into the guide plate. For cutting, knife blade is rotating along the oval orbit by D.C.motor, slider and crank mechanism. By rotating, the tip of the knife blade is projected a little from guide plate, and cutting is done at the boundary between the bone and meat. Strain gauges are attached to the guide plate, therefore, the guide plate can be measured its own stress of bending, torsion, shearing, and compression. The complete set of intelligent cutter is installed to the six-axis industrial robot. By using this intelligent cutter and control program, it is succeeded to separate automatically the scapula and the meat or tendon surrounding it. The improved type intelligent cutter was also developed to separate the joint without cutting the bone. By using the cutter, it is succeeded to separate the joint between scapula and humerus automatically with little damage to the bones.

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Laser ablation phenomena of aluminum with the fourth harmonics of Nd:YAG laser is analyzed using the modified molecular dynamics (MD), which has been developed previously by Ohmura and Fukumoto. In the modified MD method, the MD calculation for metal is carried out compensating the heat conduction by free electrons at each time step. Main conclusions are summarized as follows: (1) When the fluence is constant, there is an optimal irradiance of the laser pulse to make the number of evaporated atoms be the maximum. The ratio of evaporation energy to the laser energy absorbed in the material becomes the maximum at this optimal irradiance. (2) There are two types in laser ablation process. One is explosive evaporation which occurs when pulse width is extremely short, and the other is relatively calm evaporation which occurs when pulse width is comparatively long. In the former process, a comparatively large particles scatter, and in the latter process, the size of scattering particles is relatively small. (3) For the ultrafast laser irradiation, the evaporation threshold fluence of aluminum is about 20 mJ/cm².

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The super heat resisting alloy Inconel 718 used in gas turbines is known as difficult-to-machine materials. Under the same cutting conditions, the tool wear progresses at a noticeably quicker pace than that in cutting metals such as carbon steel. At the present time, the cutting speed is reduced during machining Inconel 718. There is an increasing demand for more efficient cutting in this field. Accordingly, a high speed cutting was attempted at increased cutting fluid flow rate by injecting fluid at a high pressure to the cutting edge. As a result, as the injection speed of the cutting fluid went up, the cutting temperature was reduced and the flank wear was reduced. And these experiments showed the prospective result that the cutting speed could be increased with high pressurized cutting fluid (high pressure injection). In the next step, cutting of Inconel 718 was attempted by using a rotary tool under the high pressure injection. Furthermore, the flank wear was reduced and the tool life could be improved.

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Indium tin oxide(ITO)films were prepared on glass substrates at low temperatures by ion beam sputtering.Growth of the films was assisted by He ion beam irradiation. Optical transmission and electrical resistivitywere then measured. In addition, FE-SEM was used to observe the films'microstructure, which was furtherstudied by X-ray diffraction measurements. The relation between beam voltage, transmission rate and electrical resistivity is shown in this study. Finally, theoretical calculation of the Hall mobility and carrier density ITO films by the Van der Pauws method is discussed.

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A new type of deposition process, ion beam sputtering enhanced by electron beam excited plasma, was proposed in order to deposit hydrogen-free and sp³ bonding rich diamond-like carbon (DLC) films. In the process, single carbon ions and atoms are generated by ion beam sputtering, and the single atoms are ionized by collision with an electron beam. The results of enhancement by electron beam excited plasma are as follows. Firstly, growth rates of DLC film increase. Secondly, continuous and smooth DLC films are deposited without droplets. Thirdly, Raman spectroscopy of DLC films infers the change of film structure to higher sp³ bonding content. Fourthly, DLC films are infrared transparent at the wavelength of 2.5-25μm, and finally, the friction coefficient between a steel ball and a doped silicon wafer decreases by coating DLC film.

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Drawing of metal wire has been conducted using a hole die, in which the integrity of hole is very important to warrant the quality of wire. Lapping of inner wall of the hole has been performed usually with hand-finishing using a bar daubed the paste kneaded the diamond powder. Hand working, however, needs long time to finish the hole. High speed flow finishing method developed recently, seems to have an excellent performance of the polishing of the hole die. Setup of the hole die finishing has newly developed. It is found that the surface roughness of inner wall of the hole decreases with the slurry flow passes, but that finishing time is very short. Experiments show that the flow finishing yields the smoothed surface and desirable shape of the hole.

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Multi-wire saw which is one of the slicing methods of a silicon ingot uses slurry mixed free abrasive grains and dispersion oil. Composition of the slurry gives a remarkable influence on slicing characteristics in this slicing method. However, it has a tendency to be decided by a user's experience or a maker's recommendable value. This study aims at improving the slicing characteristics, and elucidating optimum condition of the slurry from the behavior of slurry viscosity and distribution of grain size used the multi-wire saw. For this purpose, not only the composition of the slurry is especially considered from a viewpoint of rheology, but also the slicing characteristics are examined when the grain size distribution is changed by mixing three kinds of abrasive grain. According to this result, it is clear that optimum slurry concentration is obtained by comparison with the theoretical slurry viscosity by Jeffery and measured viscosity. Furthermore, it is found that slicing efficiency is changed by the grain size distribution. In conclusion, the optimum conditions of both the slurry viscosity and the grain size are found for obtaining highest slicing performances.

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In the atmospheric pressure plasma CVD process, further investigations for higher deposition rate of amorphous silicon (a-Si) films were performed. High density silicon particles would be generated in gas phase for the high growth rate condition, so it was very important to remove particles for fabricating homogeneous silicon films. In order to remove silicon particles, flow analysis in the atmospheric pressure plasma CVD apparatus was performed. Furthermore, the surface of the silicon films made with different gas circulation rate was observed by SEM. The results showed that reactive gas could be drawn more efficiently by increasing the gas circulation rate from 340 l/min to 1260 l/min. It became possible to avoid sticking particles on the silicon film surface by employing the gas circulation pump with larger flow rate of 1260 l/min. The maximum deposition rate without substrate scan was 1.6μm/s for the silane ratio of 5% and the input power of 2000W. In this condition, a-Si film of 0.5μm thick could be fabricated at the substrate scanning speed of 16mm/s.

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