This paper proposes an adaptive human-machine interface to match human satisfaction which is evaluated by the satisfaction measurement system with neural network based on measuring electroencephalogram (EEG). This adaptive human-machine interface can adapt to individual operators and varying context based on human satisfaction. A prototype system was developed using a pacing mental task to test the proposed human-machine interface. The result of experiments showed that the adaptive human-machine interface which understands individual human satisfaction in real time and takes adaptive action based on operator's satisfaction change has the possibility in heightening or maintaining human satisfaction rather than other work styles such as machine paced mode and self-paced mode.
The coolant reduces the grinding temperature and prevents the grinding wheel wear. The wear of grinding wheel, especially in the formed grinding to the difficult grinding materials, is disliked for the preservation of the exact size of the workpieces. So the new coolant nozzle which is named floating nozzle has been developed to decrease the grinding temperature and the wear of superabrasive grinding wheel. The new nozzle consist of the graphite and is pushed to the grinding wheel by the weak rigidity of spring. When the surface shape of the top of nozzle becomes the same as the circumference configuration of grinding wheel, it will have floated and separated from the grinding wheel owing to the pressure of grinding fluid. Therefore the narrow gap between the grinding wheel and the nozzle is made and the grinding fluid adheres to the wheel. Then the new nozzle cuts off the airflow around the grinding wheel and the adhered coolant is always supplied just to the grinding point. In the result of experiment on grinding SiC and Si3N4 with the new nozzle, it showed the high performance of grinding ability on the dressing interval, the specific grinding energy and the surface roughness.
Within the micromachining field, which is based on semiconductor manufacturing technology, wet etching and plasma etching are generally used as the isotropic etching for producing movable parts on silicon wafer. However, these methods have the following disadvantages. 1) Wet etching; (1) Dynamic damage such as surface tension occurs, (2) It is difficult to perform in-line etching, 2) Plasma etching; (1) Thermal damage due to plasma, (2) Detoxication at high-temperature is required. To solve them, it is proposed a new isotropic dry etching using CIF, gas. The following results are obtained experimentally; (1) Si can be etched isotropically by CIF3 gas at room temperature and atmospheric pressure, (2) Ni film electroplated and Cr film sputtered are useful as makes for CIF, gas dry etching, (3) Ni rotor electroplated on Si could be released by the proposed CIF3 gas etching.
This study aims to clarify the drilling properties and to find out the optimum drilling procedure for high strength titanium alloy (beta-titanium alloy; Ti-3Al-8V-6Cr-4Mo-4Zr). The various drilling tests with high speed steel (H.S.S.) and carbide drills were conducted under the wet cutting conditions. Cutting force, drill life, drill wear etc. when cutting the alloy were compared with those of Ti-6Al-4V. The results obtained were as follows: (1) The drill geometries recommended for Ti-3Al-8V-6Cr-4Mo-4Zr were the almost same as the geometries for Ti-6Al-4V. (2) Not only the average cutting force but also vibration of the force when drilling Ti-3Al-8V-6Cr-4Mo-4Zr was higher than that of Ti-6Al-4V. (3) In the case of carbide drill, the fracture of cutting edge occurred very frequently by the jamming of chip, and drill life became very short. (4) Carbide solid drill showed over 3 times longer life than H.S.S. drill when smooth chip discharge was achieved by the adoption of the drill cutting edge with nick and the step-feed drilling without the pulling out motion.
Super-heat-resisting alloy and stainless steel used in gas turbines, aircraft components, and nuclear equipment are difficult to machine because their cutting temperatures are high compared to carbon steel. More efficient cutting is thus required. A rotary tool cuts materials without greatly increasing cutting temperature. By applying a self-propelled fabricated rotary tool for cutting super-heat-resisting alloy, cutting speed could be increased about three times for Inconel 718 and about five times for SUS304, and that minimum surface roughness was obtained when the rotary tool was tilted 30 degrees.
Formation of plastic material has been generally performed by injection molding, compression molding and so on. These methods are effective for mass production, but need expensive molds. On the other hand, a laser beam makes it possible to deform a material by the thermal stress. Therefore, a flexible precision deformation is possible with YAG laser because of its easy handling and good condensation. This laser forming method without a mold can be applied to a trial production or a large variety of products in small lots. In this study, machining characteristics and deformation mechanism of plastic with YAG laser were made clear by the experimental analysis. Bending angle increases rapidly in cooling process after laser irradiation and takes the largest angle under a certain energy density. Higher feed rate leads to an unstable machining, so proper slow feed rate and low power condition are recommended in order to obtain the better machining result. It is also possible to deform a continual curve surface by giving the feed perpendicular to the scanning direction. Furthermore, in the case of plastics, bending direction can be controlled by selective coating of paint on the top or bottom surface of the specimen with one-side laser irradiation.
Masayuki IKEDA, Takashi NIWA, Takayuki SHIBATA, Akio CHIBA and Yoshimi TAKAHASHI Demand for the high frequency quartz oscillator is significantly increasing. In order to generate 100 MHz band frequency directly, the thickness of quartz must be thinner than 17 u m and the thickness accuracy must be smaller than nanometer. This paper deals with the chemical ablation of the quartz crystal wafer with an ArF excimer Laser in CF2Br2 gas. Effects of the reactive gas pressure, beam energy fluence etc. on the surface features, roughness and removal rate were investigated experimentally. It was shown that oscillating frequency of the quartz wafer will be able to control by ArF laser chemical ablation.
This paper presents a new micro-machining using a small particle controlled by optical radiation pressure induced by focused laser light, which is based on laser trapping technology. It is known that the particle of several micrometer can be trapped and moved in liquid by optical radiation pressure force, which is as small as pN to nN. It is so called laser trapping technology. In this paper, the new micro-machining are proposed, that is using small dielectric particle like a diamond grain or a silica sphere, controlled by optical radiation pressure as a machining tool. In order to verify the feasibility of new micro-machining, at first, computer simulation of trapping force are performed. The simulation results suggest that the objective with larger numerical aperture and the particles with larger refractive index are suitable for this micro-machining. Second, fundamental experiments are carried out based on the simulation results. The laser trapped diamond grain is moved at the constant path in hundreds of times on the silicon wafer surface in the machining fluid. After that, the surface to be machined is observed by using AFM. From the AFM image, it is found that the diamond grain removes the silicon wafer surface with the depth of several nanometer, even if the pressure force is as small as 0.1nN. Furthermore, it is suggested that rotating diamond grain is more efficient for micro-machining than the non-rotating diamond grain, and that even a silica sphere with smaller refractive index will be able to perform micromachining for the surface with low mechanical strength.
Using atmospheric pressure plasma CVD (chemical vapor deposition) technique, hydrogenated amorphous Si1-xCx (a-Si1-xCx:H) films were deposited with extremely high deposition rate. The films were prepared on Si(001) wafers in atmospheric pressure VHF (very high frequency) plasma of gas mixtures containing He, H2, SiH4 and CH4. Film properties (structure, density and composition of a-Si1-xCx:H) were studied as a function of CH4 concentration by TEM (transmission electron microscopy), AES (Auger electron spectroscopy) and IR (infrared) absorption spectroscopy. Relation between IR absorption spectra and chemical resistance of the films to 15% KOH solution was also investigated. The maximum deposition rate was 50nm/s, which was more than 10 times faster than that achieved by the conventional plasma CVD technique. It was found that CH4 molecules contributed to the film growth when SiH4 was co-existed with SiH4 to CH4 concentration ratio of 1/10. In this case, C to Si composition ratio in the film was 2 (a-Si0.33C0.67:H). The density of a-Si1-xCx:H film was about .1.5g/cm3 being less than half of the crystalline value of SiC. The a-Si0.33C0.67:H film was not etched by KOH solution, which was supported by IR analysis of the Si-C stretching vibration mode.
This paper presents the constituent features of the newly developed water-soluble coolant for the multiwire saw slicing of 400mm-diameter silicon ingots. Although the water-soluble coolant has long been awaited for its intrinsic merits over the conventional mineral oil-based coolants, it was not adoptable to the large diameter slicing for its poor ability to suspend abrasives in the slurry. This newly developed coolant is the first successful water-soluble coolant to slice 400mm-diameter ingots, and has the following constituent features; (1) Polypropyleneglycol (PPG) is chosen as a base of the coolant which has no peculiar odor, and has a good bio-degradability. (2) The coolant contains approx. 20wt% of water with chemical affinity to bentonite, and gives non-flammability and non-evaporative characteristics. (3) In order to maintain the viscosity level and the good suspension of abrasives, the coolant contains 3 viscosity adjusting additives; bentonito (thixotropic rheology), cellulose (rheopectic rheology), and synthetic mica (constant viscosity).
Magnetic disks are loaded cyclically by a magnetic head during the contact start/stop (CSS) operation and occasionally encounter irregular stiction. Here, the strength of texture formed with the photolithograpy prosess or laser beam process is investigated using repeated load test on aluminum and glass substrate disks. During repeated load tests, the top area of lands or bumps composed of texture surfaces starts wearing away at a morphology level. Then, the lands or bumps are allowed to subside with repeated load. Finally, the stiction force is increased, because the slider begins to make a contact with the ground surfaces around lands and bumps. This behavior is more distinct on aluminum substrate disks than glass substrate disks.
Experimental estimation is carried out on the clearance between anode can and gasket of silver oxide battery. Although the qualitative evaluation of electrolyte leakage of silver oxide batteries is given by IEC standard, it presents no quantity of leaked electrolyte but outside appearance. In this paper, flame analysis is carried out the typical samples of each grades of IEC standard for watch batteries, and the relationship between each grade of IEC standard and quantity of leaked electrolyte is given. Leak speed of electrolyte is estimated by the experimental data on alkaline creeping for the copper electrode. On account of these data, cross section area of leak path in the boundary zone between anode can and gasket is estimated. The clearance varies as time elapses, so its behavior is investigated in the valuation of leakage for silver oxide batteries under high temperature and high humidity surroundings. In conclusion, variation of clearance or of leak speed of electrolyte is an important parameter for better sealing.
OD-Blade slicing has many demands on higher level slicing in regard to slicing efficiency and accuracy. This slicing method, however, is caused to increase straightness, waviness and edge chipping at the slicing groove surface owing to elastic deformation of OD-Blade occurred during slicing, and it is one of the most reason for deterioration of slicing accuracy. This study examines the OD-Blade slicing accuracy caused by the blade elastic deformation due to an asymmetric wear of the grain parts, furthermore, describes the effect of applied vibration to the workpiece in the vibration OD-Blade slicing that can be brought out high efficiency slicing by decreasing the blade elastic deformation. The theoretical consideration on the vibration slicing mechanism divides into 3 processes such as (a) contact process, (b) separate process and (c) access process from the behavior between the OD-Blade and the workpiece, and examines the vibration effect in each vibration process. As the results from this theoretical consideration and analysis on the behavior of the OD-Blade in the vibration slicing, although the blade elastic deformation is caused in the contact process, it is found that self corrective effect from the blade elastic deformation is carried out in the separate and access process. Furthermore, it is clarified that the blade elastic deformation in the vibration slicing decreases as compared with one in the non-vibration slicing.
This paper introduces the generalized theoretical expressions for load distribution and static stiffness of multiple row angular contact ball hearing-spindle system with front hearings including an angle misalignment in inner ring. The theoretical and experimental results are further examined for a small type surface grinding machine spindle under various misalignment conditions. The results are summarized as follows. (1) Good agreement is shown between the experimental and theoretical results for various bearing combinations. (2) It is confirmed that the misalignment absorptivity of DF (Face to Face) combination is the highest than those of DB (Back to Back) and others. The DF combination makes the maximum ball load in front bearings to minimum conditions, and the axial stiffness of the system to maximum. (3) For the radial stiffness of the system, the best bearing combination is BFF, three type bearings (DB+Face), and next one is DB.
A method is proposed for automatic optimization of image segmentation procedures, which is based on the genetic algorithm and an original technique called "Male-female intersection". An image segmentation module corresponds to an individual in GA and it consists of connected filter primitives that realize fundamental image processing functions with specific parameters. Common boundary condition on each module is easily given by the pair of an input and goal image that enables users to clarify their requirement to the optimizer. A population includes modules with different combination of parameters. Effective evolution with reasonable computational cost can be performed by MF intersection over the populations. Furthermore, an image processing hardware is utilized in a prototype system in order to speed up image processing computation. From many experiments with images of the real world, effectiveness and practical availability of the proposed method is shown.
The authors have been studying pre-rolling behavior of the rolling elements called "Nonlinear Spring Behavior (NSB)" which has the problem that the system using these elements is easy to vibrate. To measure NSB which shows the hysterisis curve between the force acted on the element and its displacement, two simple methods called "Hand Operated Force Method" and "Minute Operated Force Method" are presented in this paper. NSB of the linear ball guide ways for the table and the ball bearings which support the servomotor rotor shaft is measured by these two methods. The results agree with those measured by a usual method. Futhermore, the reproducibility of two methods is studied.
This paper deals with the kinematic calibration for parallel mechanisms using inverse kinematics. The calibration method newly developed in this paper is based on solving simultaneous equations which consists of inverse kinematic functions. This method reduces the position and orientation errors of parallel mechanisms, which caused by the deviations of kinematic parameters such as a rod length or a slide fixed angle. This study has been achieved for parallel mechanism based milling machine, HexaM, developed by our company. The principle of this method is first described, then the validity of this method is verified by simulations and experiments performed on HexaM.
This paper deals with the optimum design of the torsional elastic hinge instead of the flexure hinge used as the revolutionary joint of the precise mechanism. Influence of the torsion beam dimensions on the flexural stiffness and torsional compliance of the hinge is investigated by using the finite element method, and the stiffness is compared with that of the conventional circular notched flexure hinge. As a result, the torsional hinge with the same stiffness as the flexure hinge has several times higher rotational angle under a maximum stress constraint condition. A displacement amplifier with the torsional hinge shows that the measured stiffness agrees with the calculated result, and the magnifying efficiency is 86%. By notching to the torsion beam center, the ratio of the flexural stiffness to the torsional stiffness has increased 55%, and the rotational angle has increased 19%.
In this study, the technology that detects the small cracks caused in a sodium lamp tube on a production line is developed. In particular, in this report, the detection principle and the experimental apparatus produced based on this principle are discussed. The crack is illuminated by a laser and the light scattered backward by the crack is collected by a Fresnel lens. The light intensity is converted into an electric signal by a photomultiplier tube. Experimental results indicate that cracks longer than 1.0 mm are detected automatically. This detection principle is analyzed theoretically using the Maxwell equation. It is verified experimentally and theoretically that the detection principle is effective for the detection of cracks in a sodium lamp tube.
A new type piezoelectric microcantilever which can be actuated in three orthogonal directions and can detect its deflection is proposed for the application for scanning force microscopy. A "T-shaped" cantilever with one piezoelectric layer is designed. Calculations show that the cantilever has a scanning area larger than 1×1 μm and vertical resolution smaller than 1 nm. The microfabrication process including the deposition of 3-μm-thick PZT film by sol-gel method is developed, and a test device is successfully fabricated.