As a base to improve the positioning accuracy by the real time compensation of the thermal elongation of ball-screw, it is important the improvement of the estimation accuracy on the thermal elongation of ball-screw. In this paper the improvement is carried out under two processes ; namely, a process to improve the measurement accuracy of the elongation, in which it is eliminated the influences due to inertia force of table at the stroke ends and due to thermal elongation of the displacement measuring system during experiment, and another process to improve the estimation accuracy of the elongation, in which the longitudinal temperature distribution of the ball-screw is measured in detail at fifteen points by the optical telemeter system developed. It is clarified that the estimation accuracy of -2.50∼+2.58 μm is accomplished under several conditions less than 20m/min table speed.

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Polishing is widely used in the finishing process of hard and brittle materials. This is because the surfaces finished by polishing don't contain damage, and their degree of roughness is less than that of other processes. However, polishing has some disadvantages ; for example, low efficiency and also the effect that the waste material which is generated may have on the environment. Conversely, a grinding process has the following advantages ; it is highly efficient, more environmentally friendly and various shapes can easily be obtained. However, the surface quality is worse than that of polishing. Therefore, if a new mirror-grinding wheel can be developed, we will be able to obtain a smooth ground surface as good as polishing. Historically, people have used some specific natural stones as grinding tools. Some of them outperform artificial grinding tools in the finishing process. In this paper, the fundamental characteristics of natural whetstones will be examined. It was found that their structure was composed of layers. Also, a new grinding wheel has been developed. It has a layered structure, and flake graphite was used for the layers. The capability of the newly developed grinding stone was measured by performing a dry grinding test. The work material was a silicon wafer. The ground surface roughness, Ra, was improved from 14nm to 3nm. This grinding stone could be used for mirror grinding.

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Diode laser beam of 10 W was applied to laser forming of stainless steel of about 0.1 mm in thickness. The beams were focused on the workpiece surface and scanned on a straight line. The workpiece is thin and the beam diameter is large so that bending is caused due to buckling. In this mechanism, the bending direction is not fixed ; the workpiece bends toward or away the beam. The bending angle is greatly influenced by the size and shape of the workpiece. Thick workpiece bends toward the beam ; on the other hand, for thinner ones, bending occurs in both directions under the same beam irradiation conditions.
In the present paper, experiments are carried out for thin plates under various conditions. We propose a new control method of bending directions and an experimental formula for bending angle.

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The first report proposed ”non abrasive ultrasonic vibration polishing” as a new method of polishing CVD diamond films and clarified that the titanium is the best tool material for polishing and thin oil film applied on working surface accelerates polishing speed by preventing adhesion of titanium to diamond. In order to apply this polishing method to practical use to finish coated diamond of cutting tools and forming dies, continuous polishing by this method is attempted under various conditions such as vibration amplitude, polishing load, tool feed, and overlapping frequency. As a result, it is obtained that (1) polishing action occurs remarkably by using titanium tool and applying thin oil film on working surface, (2) polishing action easily occurs under the condition where vibration amplitude is 7 to 11 μ m_p-p, polishing load is 6 to 10N, tool feed is 2 to 6 mm/min, (3) enough smooth surface for cutting tools and forming dies can be practically realized by proper combination of vibration amplitude, polishing load, tool feed and overlapping frequency.

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Diamond-like Carbon (DLC) films are usually deposited under low pressure, typically below 10 Pa. Atmospheric pressure deposition of DLC films is promising technique to realize in-process and in-use coating of DLC films. Here we report the development of the nanopulse plasma chemical vapor deposition method using static induction (SI) thyristor and application of the synthesis method to deposit DLC films, and show that DLC films with excellent mechanical performance can be prepared at subatmospheric pressure at 26.7 kPa (200 Torr). The characteristics of the thus-obtained DLC films show two broad peaks of the disordered band at 1360 cm^-1 and the graphitic band at 1580 cm^-1 by Raman spectroscopy and the thickness is 1.6 μm with the surface roughness of 0.07 nmRa. The hardness of the DLC film as measured with nanoindentor is 20.8 GPa and elastic modulus is 170 GPa.

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NAS 979 is a well-known standard for testing motion accuracy of multi-axis machine tools. One of the test methods of the standard is to cut a cone frustum and measure its accuracy. Although it has been established for long time, it is still used since a better method does not exist. Ball bar test seems to be a more convenient method for measuring the motion accuracy because NAS 979 needs two processes that include machining and measuring. In this study, validity of NAS 979 is estimated first. Next, the cutter path of cone frustum cutting substituted to NAS 979 on spindle-tilt type 5-axis MC is studied. Finally, a ball bar measurement method equivalent to cone frustum cutting test is proposed and executed on a real machine.

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Diamond-Like carbon (DLC) films have been widely recognized as a tribo-coating material because of its outstanding mechanical properties. When DLC films are distorted with the deformation of the soft substrate, it is problem that fragile DLC films are strongly damaged. In this study segment-structured DLC films were prepared on Al substrate to prevent fractures of DLC film. Deformation behavior of segment-structured DLC films was investigated by four-point bending and ball-on-disk test. In bending test, substrate strain under groove was significantly larger than average strain. It is also indicated that strain of segment-structured DLC films were decreased from the result of FEA. Tribological properties of segment-structured DLC film were superior to continuous film when the surface coverage ratio for segment structure of DLC film is larger than 70%.

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The handling of various works with practicability is required in the automatic assembly system for job shop type production. Our goal is the development of the fixture with the above function. This paper describes the “active flexible fixture (AFLEF)” on plane level as a prototype of the goal. The AFLEF is an active and practical fixture, and it can fix any work rigidly and position the fixed work at a few millimeters to correct the position error after gripping. Its structure is multi-fingered hand type, but it is not more dexterous than general robot-hands but more practical than them. As results of the experiments in rigid fixing and short positioning, the displacement of the fixed work under external force 9.8 N was within 0.3 mm and 0.3 deg. and the maximum positioning error in positioning length 3.0 mm was within 0.3 mm and 0.3 deg..

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We propose the non-contact film thickness measurement method for various materials based on photothermal effect. We illuminate nanosecond pulse laser to the film surface. The various kinds of elastic waves whose maximum frequency is several hundred MHz are excited by photothermal effect. And then, only elastic wave which depends on the film thickness remains selectively, because the resonance phenomena occur between boundary surfaces of the acoustic impedance. The film thickness can be calculated from this detected resonance frequency. In this report, we verified the generation mechanism of resonance wave by photothermal effect. We propose the collector optics type Twyman-green interferometer as the non-contact measurement method for high-frequency vibration of rough surface. In this interferometer, we introduce the objective lens to collect diffused light from rough surface and detect changes of light intensity by high-frequency response photodiode. Using the single layer film whose thickness is 1mm±0.05mm, we can detect the resonance frequency that is 3.1MHz, and the calculated film thickness is 1.035mm.

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A 2-DOF robotic arm using electrostatic film actuators has been developed. The electrostatic actuator consists of slider and stator films that are made of polyimide FPC (flexible printed circuit) films in which three-phase parallel electrodes with a width of 100μm are embedded at regular intervals of 200μm. The electrostatic actuator has unique characteristics, such as lightweight, high-power, and flexible. Besides, it can directly generate large force without reduction gears. In this paper, we discuss utilization of the electrostatic actuator for consumer robots, and develop a prototype robotic arm. The robotic arm consists of an upper arm and a forearm both with the electrostatic actuators, but in different configurations. In the upper arm, flexible electrostatic actuator is situated in bent state along inside wall of the arm. This arrangement enables putting a large actuator in a narrow space. In the forearm, a pair of actuators constructs antagonistic muscle-like structure to reduce the total weight of the arm. The upper arm actuator and forearm actuator generates joint torque of 34.5N·cm and 9N·cm, respectively. Step responses of the robotic arm in a position feedback system are measured. Finally, direct teaching and playback of a pick-and-place task was performed utilizing fine back-drivability of the robotic arm.

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The supply method of electric power consumed in rotating side is an important problem which may decide the system realization. This paper deals with a method to increase the current capacity of received power source by non-contact power supply. Experimentally it is examined the influence of the unit number of the exciting coil, the unit number of the excited coil and the gap length between the both coils. Adoption of plural units of exciting coil and plural units of excited coil makes the increase in the current capacity of received power source. The received power source of 15V×345mA is realized by four units of exciting coil and four units of excited coil, and the capacity of 345mA is nearly three and a half times of the capacity by one unit of exciting coil and one unit of excited coil.

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Collimator lens makes rays of semiconductor laser accurately parallel in the laser scanner. The most frequently used method of joining lenses is to clamp the lens near its edge by a shoulder of the housing and spacer. In the conventional method, the temperature change cause the lenses to move from the appropriate position because the coefficients of thermal expansion of the lenses are greatly different from those of the metallic housing and spacers. Therefore, the beam spots on an image plane are deteriorated. So we have developed the new method of joining collimator lenses with the shrink fitter and the plastic ring. In this method, the optical axes of the lenses in the housing coincide with each other by the shrink fitter. In addition, the plastic ring keep the spacing of the lenses constant in the optical axis when the environmental temperature changes. Therefore, the new method realized the high performance laser scanner at any temperature change. In this paper, we examined the validity of the new method theoretically and experimentally

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In most of conventional optical displacement sensors when utilized for the measurement of engineered surfaces, outliers caused by optical speckle noise are lilely to occur depending on the target surface characteristics. To reduce such noise, we invented a new optical correction system for the optical displacement sensor. However, the speckle noise is still marked in small surface roughness range. So the laser irradiation spot of our previously developed optical stylus is enlarged to the knife-edge direction in this study so that the optical speckle noise could be moderated. Fairly good outlier compensation effect was experimentally observed and similar profile data to mechanical one was also obtained.

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To obtain the internal structure of a micron-sized microsphere, we propose the proximal two-beam optical tweezers as the precise microsphere rotational method. In this method, we harness the light pressure generated by light absorption as rotating torque. We decided to illuminate the proximal two points in each from different directions using two beams. In this case, the light pressure generated by light absorption is made to act as rotating torque. Using this proposed method, we can control the rotational velocity of a microsphere regardless of refractive index distribution by non-contact operation. In this paper, we mention the experimental results of rotating a microsphere whose diameter is 10μm by proximal two-beam optical tweezers. We obtain the projection images by rotating microsphere, and we convert the projection images into 3-dimensional absorption distribution by using filtered back projection which is known as a reconstruction method for computed tomography. To improve the adverse influences of refraction, we consider the illumination optics. As a result, the distribution of the internal submicron-defect in the microsphere can be analyzed.

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A low-pass filter is applied mostly to finite length data. Because of this, unexpected vibration occurs at the end of data as an output of the low-pass filter. To solve this problem, use of a Gaussian regression (GR) filter and a point symmetric extension method has been proposed. However, the former method is difficult to handle because its transmission characteristic differs from that of the low-pass filter, and the latter method cannot be applied when the data end shows an abnormal value. Therefore, in this paper the following three methods are proposed as a solution to the vibration problem that occurs at the data end. The first method is to use a generalized low-pass filter of which regression curve's coefficient is fixed so that the same transmission characteristic as that of the low-pass filter is obtained. The second method is to use a spatial low-pass filter to which a point symmetric extension method is applied after replacing the data end with the output of the generalized low-pass filter so that the abnormal value at the data end is accommodated. The third method is to use a frequency low-pass filter that provides the same output as the second method does. All these three methods solve the data-end vibration problem, and provide the same output as that of a low-pass filter when data other than at the data end are applied.

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Electro-rheological Gel (ERG) is developed to overcome two defects of Electro-rheological Fluid (ERF) ; one is sedimentation of ER particles, the other is that the seal structure is needed to apply ERF to machine elements. The developed ERG is composed of ER particles and silicone gel. The ER particles are sustained by the gel component, and thus will not precipitate out, which suppresses the decrease in ER effect associated with precipitation. The ERG shows the wide range of shear stress variation in response to the applied electric field. This high performance of ERG is originated in a different mechanism from the ERFs. To apply the electric field to the ERG, it is necessary to sandwich the ERG between plane-parallel electrodes. However, it is not convenient for the practical use to wire the both of electrodes for high voltage supply. In this study, the one-sided structured electrodes are proposed in order to simplify the structure of the wiring. The basic characteristics of ERG on one-sided electrodes are evaluated experimentally. The result shows that its electrodes provide almost same performances as the conventional plane-parallel type. The one-sided ERG mechanism is especially useful in the application of ERG device for rotating or sliding parts.

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Nowadays most of die and mold makers use High Speed Cutting or Machining in cavity and core manufacturing. However, finishing processes for injection molding molds and die casting dies are done by EDM because these applications have many thin and deep cavities to be machined. Otherwise, the long solid carbide milling cutters are necessary for machining these molds and dies. To save set-up time and avoid using the long solid carbide milling cutters, we have proposed 3+2-axis high speed machining on a 5-axis machining center. The 3+2-axis machining is the sequence of machining by indexing titled tool axis on 5-axis machining center. In the 3+2-axis machining process, the sequence of indexing angles must be determined automatically, because the shape of the die and mold is very complex to determine the indexing angles by an operator. Therefore, the main objective of this research is to propose an automatic determination method of the sequence of indexing angles for machining the die and mold. We have proposed, in the first report, the calculation method of optimum indexing angle candidates for given required machining surfaces using normal vectors of the surface and effective cutting edge shape, and the machinable area derivation method of calculated indexing angle based on inverse offset method with state flag. In this report, we extend the proposed calculation method to determine the sequence of indexing angles for a complex machining shape. Firstly, in order to represent machinable information of facet, a new facet data structure is proposed. Secondary, the precise representation of machinable area on the offset surface is proposed. Finally we illustrate an example to demonstrate the effectiveness of the proposed method.

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