Tactile display enhances reality of manipulation in master-slave manipulation system. This paper proposes a bilateral control method that incorporates tactile display signal in the control loop of the master hand actuator in order to use the master hand's actuator for both actuation and tactile display. This will eliminate the need for dedicated tactile display device on the master hand. A tactile sensor that detects vibration is attached on the slave finger. Slippage at the slave finger and texture of the object are displayed by high-pass-filtered tactile sensor signal. The onset of touch and removal of a slave finger are displayed by an asymmetrical triangular pattern that comprises of fast ascent and slow descent. The design of this pattern is based on the results of psychophysical experiments that the human fingers cannot feel the motion of a display pin slower than 0.2mm/s for protrusion and 0.5mm/s for receding motion. The operator will feel only the fast ascent of the display pin, and hence have the sensation of touch and removal even though the operator's finger is constantly touching the master hand. A low pass filter removes these additional tactile display signals in the master hand that may cause instability in the bilateral control. Experimental results show that the proposed bilateral control system enhances reality of touch and slippage in the master-slave manipulation system.

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This paper presents a novel Genetic Algorithm (GA) based autonomous feedforward compensator design for the fast-response and high-precision positioning of mechatronic systems. The positioning system is mainly composed of a robust 2-degrees-of-freedom controller with feedback and feedforward compensators. The feedback compensator ensures the robust nature against variations of load mechanical parameters and the feedforward compensator allows the positioning to be fast and precise. The feedback compensator can be theoretically synthesized by μ-Synthesis, considering the robust stability and/or performance. The feedforward compensator, on the other hand, can be autonomously designed by GA, where both structure and its parameters of the compensator are optimized to realize the desired robust positioning performance against the load inertia variation. The effectiveness of the proposed optimal design has been verified by experiments using a prototype of 2-mass resonant system.

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This paper proposes a calibration method of CMM by estimating of geometric errors. In this calibration, well-known 18 geometric errors, namely parametric errors are adapted. And a rigid body error model using these parameters that indicates the behavior of deviation is described. Calibration can be conducted by estimating of those 18 parametric errors at each dispersed point in measuring volume. In order to estimate 18 parametric errors, independent 18 sets of measurements are necessary. So we designed a measurement strategy, 2D-artifact (ball plate) was arranged in several different positions and measured based on this strategy. As a result, 18 sets of parametric error curves are estimated separately. Considering the demand of uncertainty specification, ball plate uncertainty with traceabillity is reflected to the results of estimated parametric errors. That enables the calibration results to indicate the uncertainty.

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In order to provide microscopic manipulation, the unique locomotion mechanism which is composed of four piezo elements and two electromagnets were proposed in the 1st report. Here two legs arranged on cross each other are connected by four piezo elements so that it can move in any directions, i.e. in the X and Y directions as well as rotate at the specified point precisely with the manner of inch worm. Moreover the combination of specified wave forms for piezo elements can provide “arc trajectory motion”, that is important for the micro manipulator to keep its tip end within the microscopic area. In this paper, we analyse the arc trajectory motion and design the signals of each actuator, and then we checked its motion accuracy and precise dexiterity by the CCD camera based image tracker. Finally, we confirmed that the robot can move the arc trajectoy motion with respect to any center point precisely.

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It is necessary that the inner wall of the tiny nozzle used in a water jet cleaner is very smooth and also its nozzle edge is chamfered. Finishing of the inner wall of the tiny nozzle is very difficult by ordinary finishing methods. Gyration flow finishing method recently has been newly developed in which polishing is conducted using polishing fluid suspended peach seeds and grains into olive oil. Present study focuses on the effect of the polishing fluid supplied from the back side of workpiece. It is found that the suck out of polishing fluid from the back side of workpiece is very effective for chamfering of the nozzle edge. Experiments show that the size of the peach seed has an influence on chamfering quantity of the nozzle. It is shown that the jet force of the water jet cleaner of which nozzle is polished by the polishing method is made to increase by 30%.

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Stainless steel orifice plate installed into a gas flow controlled device is necessary to finish an inner wall of it. High speed slurry flow finishing method developed in our laboratory has been applied to polish the inner wall of orifice plate. Present paper focuses on the relationship between finishing characteristics and gas flow rate through the finished orifice plate. Experiments are conducted under the conditions of high flow rate of slurry suspending the aluminum oxide grains into city water. It is found that surface roughness of the inner wall of trumped-shape hole has decreased with the flow pass number. SEM micrographs indicate that the stripe-pattern on inner wall surface of as-received orifice plate have disappeared with the slurry flow pass number, but the dimension of hole has increased in size. Measurements of gas flow volume through the polished orifice plate show that finishing charac-teristics influences on gas flow curve.

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Femtosecond laser can minimize the undesirable thermal effected zone, and hence is suitable for the processing of brittle materials. Taking advantage of this method, some glassy materials can be cut without any micro-cracks on the surface. This paper presents the drilling of ultra thin silicon wafers irradiated with femtosecond laser. In order to understand fundamental characteristics of the ablation using femtosecond laser, influence of laser parameters such as pulse energy, pulse separation time, etc. is investigated. As the pulse energy increased, the distribution of the air breakdown grew only to the side of the focusing lens and the ablation depth was saturated by the breakdown plasma which causes scattering of the laser. Therefore the highest processing rate was obtained with the maximum pulse energy not to generate the breakdown plasma. Double pulse method was useful for restraint of the swelling around the ablation crater. The swelling height was within 0.5μm with the most suitable pulse separation time (10ps-20ps).

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Higher integration of VLSI has produced the number of interconnection layers. This trend requires a high planarity to individual surfaces of interconnection layers because their irregularities must be less than the DOF (Depth of Focus) of the wafer stepper's projection lens. This suggests that the technology for achieving the global planarity within a die is required. At the planarization process, the essential factor for the global planarization is to remove materials at the top of humps of surface irregularities selectively. From the point of view, the new planarization method which utilizes the laser trapping phenomena and which has the process of intentional selective material removal at the top of humps is attempted.
On the study, at first, the laser trapping of fine particles in slurry and the formation of aggregated marks of fine particles were investigated. Secondly, material removal process by polishing after aggregated marks formed was observed. Finally, as a planarization method for irregular surface of Silicon wafer, LAFP(Laser Aggregation, Filling-up and Polishing) method was attempted. The method has two steps procedure for planarization. First step is forming aggregated marks of fine particles with laser irradiation at the specific location of recessed part of trenches on Silicon wafer surface, and the second step is polishing the Silicon wafer surface together with filled up trenched area as one continuous surface with no irregularities of wafer patterns. As an experiment, the LAFP method was applied to the silicon wafer surface which has four trenches as dummy patterns formed with FIB process, and smooth and planarized surface was obtained after polishing.

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Cutting force and surface roughness are decreased by a thin coating of dilute carboxylic acid whose number of carbon is more than 7. It is presumed that these phenomena are caused by the chemisorption of organic polarity substance molecules to Al atoms near by the dislocation. In this experiment, the coating materials are liquid paraffin containing 0.2mass% carboxylic acid (C ₈H ₁₆O ₂, C ₁₀H ₂₀O ₂ and C ₁₄H₂₈O ₂) or various kinds of 0.2mass% organic polarity substances whose number of carbon is 18. Cutting surface temperature Tis controlled between 15 to 60°C by Peltier thermo module elements. Cutting speed and depth are 1.67mm/s and 0.05mm, respectively. The following results were obtained. 1) Cutting force (F _T max and F _N max) and surface roughness Ry are decreased by the coating of carboxylic acid at the cutting surface temperature under the acid's melting point. 2) From the relation between ln(Frmax) and 1/T, activation energy is calculated at 120 to 200kJ/mol at the effective surface temperature for each acid. These values correspond to the formation energy of chemisorption between carboxylic acid molecules and Al atoms. 3)In the case of organic polarity substances except for carboxylic acid, these coating effects are not observed at the substance's melting point.

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In order to achieve damage free surface of Si wafer by a single step grinding process, each cutting edge should be controlled below the critical depth of cut. Additionally, the achievable wafer flatness by infeed grinding significantly depends upon the alignment between the wafer and the wheel. As one of the core technologies of an integrated manufacturing system for ∅300mm silicon wafer, a GMM (giant magnetostrictive material) actuated positioning/alignment device has been designed and developed to control half a ton payload at Å resolution over the several μm stroke range (about 5μm) and simultaneously to align the co-axis between the work and wheel at the resolution of 0.1″. This paper describes the design of the GMM actuator and elastically deformable mechanism for position/alignment, the control schemes and on-situ performance.

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A finite element modeling of machining of a nickel-base superalloy is presented for aiming at understanding its cutting performances and improving cutting conditions, cutting efficiency and machined surface integrity. A formulation with a dynamic explicit thermo-elastic plastic finite element method, penalty methods dealing with mechanical and thermal boundary conditions on the tool-chip contact area, and mass scaling for efficient calculation gave chip formation and cutting processes of Inconel X750 under a wide range of cutting conditions. Calculated and experimental results agreed well in cutting forces, shear angle, tool-chip contact length and stress distribution on the rake face. It was found that the rake angle had a great influence on the predicted thickness of affected layer for constant undeformed chip thickness while the cutting speed had a little. The instantaneous ratio of heat into the tool to the energy consumption due to friction on the rake face was calculated. At the beginning of cutting the ratio was greater than 100%, then decreased to 100% and less. From the results it was suggested that for better interrupted cutting with good tool cooling, cutting length per tooth may be taken as one at the ratio of 100%.

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In this paper, the performance of different types of water-soluble cutting fluids for bobbing was investigated, in terms of tool life (flank wear), crater wear and finished surface roughness with TiN and (Al, Ti)N coated high-speed steel tools. Experiments were carried out using a fly tool. The results helped clarify the following points; (1) Up to the cutting speed of 117m/min when using the TiN coated tool, a soluble cutting fluid contained with synthetic lubricating additive (SLA) improves the tool life, but it gives an extreme short tool life at a high cutting speed of 159m/min. (2) In the case of (Al, Ti)N coated tool, a soluble cutting fluid contained with SLA and surface active agent (SAA) prolongs the tool life, irrespective of the change in the cutting speed. (3) The soluble cutting fluid with both SLA and SAA, which were added in order to improve the lubricating ability, is effective for the tool life, the crater wear and the surface finish, when the (Al, Ti)N coated tool was used.

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This report aims to investigate experimentally the possibility of ductile-mode ultra-smoothness grinding of fine ceramics using a coarse grain size diamond wheel. According to previous experiments, the results obtained in the ductile-mode surface plunge grinding of fine ceramics using a coarse grain size diamond wheel, showed that grinding groove heights over 200nm(Ry) were formed on the workpiece surface by the cutting edges. To diminish the groove heights, in the research, the grinding groove height diminishing-method in which cross-feeding the workpiece at high speed normal to grinding direction is done together with simultaneously feeding at a extremely slow speed parallel to grinding direction, is devised and the availability of the method is examined by surface grinding experiments. The fine ceramic used is the hot pressed silicon carbide. The grinding wheel is the metal bond diamond wheel of the grain size of mesh #140 and the concentration of 50. The ground workpiece surface is observed with differencial interference microscope and SEM, and its roughness is measured with a interferometric surface profiler and AFM. Using this diminishing-method, the grinding groove height diminishes considerably and the surface smoothness below 10nm(Ry) or 2nm(Ra) is attained.

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Laser cleaving process is a prospective technique to divide a thin plate of brittle materials into small pieces, because of its high yield ratio and controllability. In addition, the process is carried out without coolant which causes the environmental pollution and the contamination of the electrical devices etched on the wafer. In this paper, laser cleaving of silicon wafer is conducted with pulsed Nd: YAG laser. The temperature of laser spot is measured by means of the two-color pyrometer with optical fiber and the acoustic emission caused by crack propagation is also observed. When the laser spot is scanned at the appropriate interval and velocity, the crack propagates in sequence by the corresponding laser irradiation. As a result, both high linearity of cleaved edge and fine fractured surface roughness are obtained. The thermal stress distribution induced by laser irradiation is analysed with FEM model, in which the stress intensity factor is calculated at the vicinity of the crack tip in order to clarify the criterion of crack propagation. The analysis and experiments reveal that the maximum tensile stress at the crack tip increases with temperature and the crack propagates when the stress intensity factor reaches the fracture toughness of the material.

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A method of producing minute three-dimensional components by casting was experimentally examined. In the transcription of minute shapes, the particle size of the mold material and the production method of the mold are problematic. In particular, handling of minute models and casted products is extremely difficult. Molds were prepared by the following method. First, a model to be burnt was immersed in slurry. After the slurry density was increased by the application of centrifugal force, the binder was solidified to obtain a raw mold. A mold was then obtained by burning and removing the model material through firing the raw mold. The obtained mold was immersed in a hot solution for the casting process. With immersing the mold in water, the mold underwent self-breaking and the casted product could be removed without damage or cracking. It is confirmed that the accuracy of transcription of the tasted product is approximately 10μm.

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A C60 monolayer film can grow on a graphite (Highly Oriented Pyrolitic Graphite: HOPG) substrate at a substrate temperature of 150°C. The frictional behavior of a C60 monolayer film between graphite substrates is studied using a homebuilt surface force apparatus. The mean frictional force from the C60 monolayers is estimated to be approximately 2mN, which is one-fifth that of C60 multilayer films. This result indicates that C60 molecules of the C60 monolayer sandwiched between graphite substrates roll via the nanogears of six-membered carbon rings between C60 molecules and the upper and lower graphite substrates. The C60 monolayer film maintains durability with a low frictional force of 2 mN for more than one hundred scans under a load of 10mN. This behavior does not change in the scan velocity range of 10 to 20 μm/s. Hence a novel frictional mechanism is realized in the graphite substrates sandwiching a C60 monolayer film system. It should be emphasize that the graphite substrates sandwiching a C60 monolayer film system is very promising for the realization of nanomachines and micromachines.

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