[in Japanese]

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[in Japanese]

View full abstract

[in Japanese]

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[in Japanese]

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This paper describes a design and an implementation of the glue logic, which is intended to be an infrastructural element integrated in the Programming/Execution Environment for FA Control Systems. The glue logic coordinates multiple application processes by means of message passing. Using this system, users can easily implement data-sharing and task-interlocking among multiple application programs. Furthermore, this system includes event notification and condition monitoring features in order to eliminate needs of data polling. In this paper, the requirements for the glue logic are discussed at first, then the structure of the glue logic is presented. Lastly, the implementation of the glue logic is described.

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This paper deals with a methodology of robot modeling for applying robot motion planning. Robot or robot component is modeled as a group of decision-making elements called cell. A cell is a kind of automaton which has the action objective to make uniform distribution as representing geometric shape of robot or robot component, and actions to achieve this objective. Process for making an arrangement of cell group by action of each cell is called self-organization. To give property of Self-Organization into cell, a potential function is defined on neighborhood of cell based on the concept of group theory. Each cell identically takes an action to go down its potential value. When minimal potential value is given to all cells in a group, self-organization is finished and a cell group is uniformly distributed as representing a robot component. As geometric shape of robot component is represented by a distribution of cell group, its position and direction correspond to robot's configuration. This paper describes a modeling methodology of robot or robot component by cell group, and a way of Self-Organization is expounded. And results of simple case study executed to verify the effectiveness of selforganization are reported.

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This paper deals with collision-free motion planning for an articulated robot arm. In this study, a link constructing an articulated robot arm is modeled as a group of element called cell. An articulated robot arm is represented by combining groups of the cell in each joint position. Each cell has the action objectives that represent a shape of link by distributing all cells as grid pattern in the collision-free space. Process of achieving this objective is called self-organization. Distribution of cell group obtained by self-organization is regarded as collision-free configuration of an articulated robot arm. In proposed approach, a problem of motion planning of an articulated robot arm is solved by integrating end-effector path planning from a given initial position until a target position and determination of configuration by using self-organization of cell group. This paper explains a method for planning end-effector paths, and then describes a method for determination of arm configuration for position of an end-effector. Finally, results of motion planning for a three-revolute-joint arm are reported to verify the effectiveness of proposed method.

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This paper presents an analytical approach to the problem of designing a product in consideration of its quality, i.e. the design-for-quality problem. At the stage of product design, product's quality is evaluated with Taguchi's quality loss function, which can be regarded as a measure of the generalized quality cost of the product. In the concept of the generalized quality cost, not only the traditional quality cost, which is defined as the manufacturer's cost of quality, but also the user's cost of quality and the social cost of quality are included. At first, the design-for-quality problem is formulated as a problem to minimize the expected sum of the fundamental manufacturing cost and the generalized quality cost of a product. Then, an analytical approach to this problem is proposed, assuming that the relation among quality characteristics, design parameters and noize parameters is available. In this approach, the solution of this problem is derived without performing experiments. Further, the effectiveness of this approach is investigated through an example.

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In the case of the style design based on a master model which is made by clay or wood, the production of the CAD model by fitting the measured point data has been bottleneck in the design process. This paper describes a new fitting method of 3-degree B-spline surface onto the dense measured point data. The method to determine knot location with taking account of curve length and curvature is proposed. And the parameter is set in consideration of the knot location. The master model with free form surface is measured by using the developed non-contact 3-D digitizing system. It is shown that the B-spline surface without waviness is fitted to the measured point data with high accuracy and in good condition.

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The study deals with the non-contacting ultra-precision in-process measurement of a rotating main spindle displacement in the axial direction by a laser interferometer. The displacement of main spindle, where a cutting tool is mounted, considerably affects the machining accuracy especially in the ultra-precision machining. The fluctuation of cutting force causes the spindle diplacement, which is difficult to measure since it rotates. The experimental setup of the spindle displacement measurement consists of a feed table with the positioning resolution of 1 nm and an air-borne spindle having a through hole, where a reflective mirror is mounted. Measured value at a certain rotational angle during a rotation stands for a spindle displacement since it is stable compared to that measured at an arbitrary angle. As a result, it is found that the system has the potential of making in-process displacement measurement of the rotating spindle with the accuracy of 10 nm.

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Main difficulty of binocular vision systems is how to correspond the right and left cameras' image data. A binocular machine vision system proposed in the present paper has two CCD cameras, one of which has a laser pointer that actively indicates the view point of the camera. Using this active view point, the system rotates both cameras to coincide their center of views. Then a feature point in one camera's image is easily corresponded to another because the true corresponding point can be selected from points discovered on an epipolar line by using the information of the distance between these points and the center of view. Experiments show that the proposed system recognizes the feature points indicated by LEDs and corners of a square plate, and calculates the coordinates of these points and corners.

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In Japan we are going into so called an aging society. A lot of helpers are demanded for helping the aged persons who especially go around outside of houses. A new developing navigational system which measures and indicates the lost positions of the aged would be useful for decreasing the number of the helpers. This paper described about the fundamental study on a sensor of the navigational equipment used on a road. As the result, a nonlinear equation was obtained for getting the three dimensional positions by three linear acclamations calculated by eliminating the centrifugal forces and Coriolis forces from the data measured by six linear accelerometers. These accelerometers are set at symmetrical positions to the device center on the three orthogonal axes, and measure six linear accelerations. The stability of this approach is shown by numerical simulations short term sample waves like rotating motions by mobile robot and a human walking.

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The purpose of this paper is to present a design outline and describe the characteristics of the table control system of a high density optical disk mastering machine. The table control system consists of a friction drive, a double guide air-pressurized slider, a laser interferometer and a controller. Friction drive makes it possible to position the table with 10nm accuracy over 200 mm travel. The laser interferometer system is designed to measure the position of an optical head, exposure point, using the special laser optics configuration with two reflectors, between which the optical head is located. The table is positioned with a standard deviation of 2.9 nm (σ) in a ramp command of 10μm/s and the steady-state error and the settling time are better than 10 nm and 0.15 second, respectively, in 1μm step response. The mastering machine has made pits and grooves with a track pitch of 0.65 μm and a pit width of 0.3μm.

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Teleoperation may have a good application to surgical operation of patients in risky place in emergency case. For that reason, many efforts to develop a bilateral manipulator for teleoperation, especially with surgical purpose, have been made so far. In this research, a bilateral manipulator, which is a small master slave one with a 2-axis force sensor, has been developed for the intention of surgical teleoperation. This manipulator can move linearly with knife cutting while measuring the cutting force by its sensor. In author's future work, more attention will be paid to that force. Because the force information of manipulator's end effector is the most important one in the bilateral manipulation. In this paper, the authors are going to talk about its structure and its manipulability based on PID controller. Data from features of the 2-axis force sensor and some experiments of knife cutting are included as well.

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In this investigation, ground grooves obtained by releasing a grinding wheel quickly from a workpiece during a slot grinding operation are examined in detail, in order to clarify the influence of the bond used in the grinding wheel on the generation of grooves. Experiments are carried out using a metal-bonded grinding wheel, a metal/resin-bonded grinding wheel and a resin-bonded grinding wheel. Grinding wheels with soft, elastic bonds result in narrower ground grooves. The initial chipping size for grinding wheels with soft, elastic bonds is small. The rate of decrease of chipping size after the occurrence of initial chipping due to the increase in kerf width is greater when the grinding wheel has soft, elastic bonds. Therefore, wheels with soft, elastic bonds have the function of reducing the edge-chipping size. The side surfaces of the grooves are ductile compared to the bottom surfaces, because the bottom surfaces are ground only by the periphery of the grinding wheel, whereas the side surfaces are ground with a smaller depth of cut and a greater length by the sides of the wheel.

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Reactive ion beam etching of diamond chips with oxygen ions using a Kaufman-type ion source has been investigated. Instability of thermionic emission and short life span of the thermionic tungsten filament (cathode) in a Kaufman-type ion source become problems, because the thermionic filament is attacked by the reactive oxygen species. Therefore, an electron cyclotron resonance (ECR) -type ion source which has no thermionic filament has been used in the experiment. This paper reports etching characteristics of diamond chips processed with an oxygen ion beam using an ECR-type ion source. The specific etching rate increases with increasing ion energy, and reaches a maximum rate at an ion energy of 300 eV, then decreases gradually with further increasing ion energy. The specific etching rate processed with 1000 eV oxygen ions increases with increasing ion incident angle and reaches a maximum rate at an ion incident angle of 40°, then decreases with increasing ion incident angle. The specific etching rate processed with 500 eV oxygen ions decreases with increasing ion incident angle. The specific etching rate processed with 500 eV oxygen ions at an ion incident angle of 0° which includes both physical and chemical reactions is 12 times greater than that processed with argon ions which cause only a physical sputtering reaction. Futhermore, the surface roughness of diamond before and after oxygen ion beam etching was evaluated using an atomic force microscope (AFM) and a scanning electron microscope (SEM). It was found that the specific surface roughness increases with increasing ion incident angle, and decreases with increasing ion energy.

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This paper describes a determination of the arc plasma temperature in the electrical discharge machining (EDM) process by measuring the line spectrum intensities radiated from the arc plasma. It has been generally impossible to measure the plasma temperature in EDM process, because the plasma produced in the narrow gap and accompanied with the electrode material removal is usually in an unsteady state. The spectroscopic analysis using an optical fiber and a monocrometer makes it possible to diagnose the plasma without being affected bythese obstacles. In this paper, the temperature is determined from the relative intensities of the lines radiated from three excited energy levels of copper atom. The apparant temperature of the whole radiant area obtained from the experiments is between 6000K and 8000K. However, there is a temperature distribution in the radiating area, and the measured line intensities in the experiments are integrals of contribution from each part of the whole radiant area. Therefore, the line intensities can be analyzed theoretically with the radiant body profile observed by an image converter camera. By comparing the analyzed results with the experimental data, the peak temperature is estimated to be about 10000K.

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A new method of the superfinishing is investigated, in which the cutting ability of diamond stone is controlled by changing the strength of electrolytic in-process dressing. Water-solution type coolant and metal bonded stone are used to employ the electrolytic dressing. As work materials, a carbon steel S 45 C, a bearing steel SUJ 2 and alumina are used. The results obtained are as follows. It is effective for control of electrolytic dressing to change the operating time of electrolysis or the ratio of on-time to off-time in electric pulse. As the dressing becomes stronger, the cutting ability of stone improves and the metal removal rate becomes larger. As the dressing becomes weaker, the cutting ability of stone is lost and then the surface roughness of workpiece becomes smaller. The cutting ability of stone which has been lost in finishing operation can be regenerated again applying the strong electrolysis. This in-process dressing method makes it possible to obtain the intended finishing performances of metal removal rate and surface roughness, and to finish several work materials of different machinability using a same kind of stone.

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The technique of surface modification using an ion beam is applied to the tool by using the IAD method, the IVD method, and ion plating. In these methods, however, substrate temperature rises due to ion irradiation during the process. A new fabrication method for preparing ceramic thin films named Interface Controlled Vapor Deposition (ICVD) has been developed and makes low temperature fabrication possible. In practical application, electroforming Ni is a good material for a shaver foil. However, the hardness of the electroforming Ni foil increases at high temperatures and this can shorten the life of the shaver foil. So, the ICVD method was applied to the development of a high quality zirconium nitride ceramics coated shaver foil, which has excellent mechanical properties such as surface hardness, wear resistance, friction coefficient and corrosion resistance.

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Deposition conditions and growth of CVD diamond thin plate that has high optical transparency have been studied. Transparent CVD diamond thin plates have been deposited at lower methane concentration of 0.6% independent of the difference of nucleation using arc discharge plasma jet CVD. The relation between the structural properties and optical performance of CVD diamond has been discussed by observation of its cross sectional structure. The cross sectional structure of CVD diamond thin plates was exposed by the techniques of the polishing and etching using a hot iron plate and hydrogen plasma, respectively. As a result, transparent CVD diamond plates grow in well-arranged way with less defects and impurities.

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This paper describes a fabrication technique of Pt/Ir probe tip for scanning tunneling microscope. A combination of DC and AC voltage electrochemical etching was adopted. In the DC 60V etching, the Pt/Ir wire was coarsely formed to tip shape with electrochemical discharge process. The periodical change of etching current was utilized to halt the etching process before cut of the wire. The second etching with AC potential of 2V proceed to micropolish roughness on the tip surface and to cut the wire. Whole procedures including switching the etching voltage and cutting off the voltage are automatically controlled by personal computer and photoelectric circuit. Also, the fabrication reproducibility of tips is presented.

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In contact between a surface covered with thin film of oil and a clean surface, the oil film transfers from the former to the latter. The distribution of the transferred oil shows that of the real contact surface. In this paper, the patterns of the transferred oil film were observed and it was shown that the distribution of contact surface was closely related not only to the surface finishing method but also to the structures of the machined surface. It is clarified that the hard cementites in steel surface were protruded in polishing as well as buff-finishing and, as a result, only the cementites contacted with another surface.

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