[in Japanese]

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Ultrasonic vibration cutting obtains the good finished surface when compared to the conventional cutting. However, the cutting conditions in ultrasonic vibration cutting are difficult for the public to optimize. In many cases, an expert in vibration cutting decides the cutting conditions from experience.
In this study, we are concerned with the phenomenon in deterioration of roundness in ultrasonic vibration cutting. We analyze the vibration situation with regard to the cutting part of cutting tool using FFT, and we examine the characteristics of vibration in the cutting part. This paper reports relationship between the vibration situation in the cutting part and the roundness.

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The vibration cutting has attracted attention as a precision machining method for the difficult-to-cut materials. Our purpose is to evaluate the effectiveness of the vibration cutting for various metal materials, and to characterize the vibration of work-piece during the vibration cutting.
In this report, we carry out the experiments for the vibration cutting the five types of metal -- S45C, SCM415, Inconel600, SUS304 and A2017, under the same condition. Our experimental results show that the surface roughness and the roundness of S45C, SCM415 and Inconel600 are improved largely by the vibration cutting, and the vibration of work-piece during the vibration cutting is closer to the vibration when the idling (no cutting) than during the conventional cutting. The latter result shows the cutting force of the vibration cutting is very small.

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It is difficult to manufacture the small-size irregular holes except for circular hole. Micro irregular holes slotting experiments in which the cutting edge is oscillated along the cutting direction are conducted using the ultra-sonic vibrator. As the results, by the effect on decrease of cutting force due to the ultra-sonic vibration at cutting edge, it is able to finish precisely the cutting surface with better straightness. This results show a tendency to increase with the increase of rake angle of tool. Since it is impossible to manufacture the micro irregular holes by one-pass slotting with pre-hole, it is necessary to adopt the multi-path slotting method.

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In this study, we investigate an ultrasonic-vibration-assisted end milling technique for improving the milling accuracy of products using small-diameter and high-aspect-ratio ball-nosed end mills. In our experiments, several mold cavity shapes and fine patterns are machined by the above-mentioned ultrasonic milling technique. As a result, we clarify that the improved cutting performance parameters, such as a reduced burr height, a high geometrical precision and a small surface roughness, are obtained by the proposed ultrasonic milling technique.

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The machinability in micro drilling depends on the ability of chip removal. This paper deals with cavitation effects in cutting fluid using the ultrasonic vibration in order to activate the chip control. The thrust component and behavior of chips are observed when drilling SUS304 by (TiAl)N coated tool of 0.1mm diameter. Thrust component aided cavitation is not changed as increase of speed rate, but it increased as increase of step feed. Micro drilling aided cavitation achieved longer tool life compared to conventional oiling.

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Recently, the final surface finishing of die has been operated by skilled workers and it consumes several days to finish such as a die surface of mobile phone. The aim of this study is to improve productivity of die by mechanization of finishing process using ultrasonic machining. Spherical diamond tools are trued and dressed on the machine tool in order to reduce tool run-out, then used to establish mirror surface of inclined planes. The effect of truing and dressing is evaluated by both observations of diamond abrasive grains using an optical microscope and surface roughness of ground works.

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Mirror surface finishing by skilled worker is the final process in die manufacturing. Although it establishes the desired surface finish, it is a time-consuming process. Therefore, it is required that high precision die milling or grinding replace the manual finishing, in order to minimize operation time. In the previous study, ultrasonically assisted diamond face grinding of die steel was carried out and mirror surface (0.14μmRz) was obtained. In this paper, tool vibration during grinding was observed using high-speed stroboscope filming method. And transient behavior of tool at the beginning of cut was observed, too. And relationships among behavior of ultrasonic vibration, cutting force and tool deflection were investigated to verify transient behavior of ultrasonically assisted face grinding.

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Fabrication conditions are discussed of Ni-W electroplated tools with fine grained diamond of 0.5-2µm and 2-4µm diameters. Machining performance is investigated for various work materials using these tools.

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[in Japanese]

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The present work aims to develop an ultrasonic vibration assisted polishing technology for the silicon wafer edge. This paper describes the fabrication of an experimental apparatus composed mainly of an ultrasonic polishing tool, and the experimental investigation of its performance in silicon wafer surface polishing. Fundamental experiments were carried out on the fabricated apparatus involving 200mm wafer surface in order to investigate the effects of the ultrasonic vibration on surface roughness. The experimental results indicate that applying ultrasonic vibration decreases surface roughness in the maximum by 58%.

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[in Japanese]

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This paper deals with the effect of cutting fluid on the cutting characteristics of titanium alloy with cBN tools. In particular, precision cutting experiments of Ti-6Al-4V alloy using an oil type fluid and two kinds of emulsion type fluid are carried out to clarify the influence of cutting fluids on the generation mechanism of machined surface.

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Milling tests were conducted in order to investigate the cutting performances of a binder-less PcBN tool in the machining of Ti-6Al-2Nb-1Ta, which is used as a surgical implant material. In milling under a condition with high pressure coolant, some micro chippings on the rake face of the tool were observed as a typical pattern of tool damage. The rate of tool damage was dependent on the cutting speed. However, in the case of supplying minimum quantity lubricant (MQL), the micro chippings were rarely occurred. Therefore, the rate of tool damage in milling with the application of MQL was lower than that in milling with high pressure coolant.

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Recently, resulphrized free cutting steel has attracted attention among of free cutting steels, because of environmental problems.
Resulphrized free cutting steel, however, has more scope for improvement than free cutting steel with lead addition in some researches.
The purpose of this research is consideration of adhesion on the cutting interface of the cutting tools used by experiments, and getting the index of adhesion in each tool materials.
The experiment is carried out with the lathe, and compared the results of a ZrO2 tool with a WC tool and a cermet tool.
The tool surface is analyzed elements with EPMA and the surface is checked with SEI.
The DV-Xα molecular orbital method is simulated about bonding-force between matrix element and the tool material.
As a result, it is confirmed that existence of thin layer of sulphur on the surface of the ZrO2 tool, and that the lubrication of resulphurized free cutting steel cut with the ZrO2 tool is better than with the WC tool and the cermet tool in quality from experiment results.
And the index of adhesion is obtained from simulation results.

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This study deals with the machinability of steels in turning with additional current. Tested work materials were plane carbon steel JIS S45C and BN added steel which has good machinability in turning at high cutting speed. Turning tests were performed by carbide tool K10, P10, P20, P30, Cemet tool and TiCN coated carbide tool to clarify the influence of chemical compositions of tool materials on the cutting mechanism of BN added steel. The cutting force was investigated practically and these results were discussed.

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Machining performance of driven rotary tool for SUS304 was examined in this report. The rotary tool is attached to a milling axis on a multi tasking lathe which has B axis control. Different from a self-propelled rotary tool, the driven rotary tool can widely control the tool rotation speed. Then we measured the tool rake face temperature during the cutting by using a thermograph camera. Tool surface temperature at the point 180 degree rotation from cutting point was about 200°C even at the cutting speed of 500m/min. In addition, the tool wear decreased greatly compared with the self-propelled rotary tool or the fixed button tool.

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This study aims to develop cutting tools of heat release type that used high heat conductivity materials for heat-resistant alloy in dry cutting. The experiments were conducted to examine the methods that radiate the heat flowed into the cutting tool immediately, and the effect of heat release on tool wear were investigated. It was found that the placing high heat conductivity material on the cutting tool was available to suppress the tool wear.

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The On-the-machine cutting-Tool-Regenerating Technology, in which the worn out cutting tool is regenerated by coating a film on the tool surface on machine without tool-exchange, has been proposed and is being developed in recent years. In this study, the diamond-like carbon (DLC) film forming is carried out under atmospheric pressure in order to regenerate a high hardness DLC film as a coated film of a cutting tool on machine. It is successful that a DLC film with Vickers hardness 2836 can be generated at a speed of 18[μm/h] under atmospheric pressure up to now.

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[in Japanese]

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A dynamic damper utilizing the magnetic fluid has been developed in order to bore the deep hole. This paper deals with the experimental results such as chatter vibration, surface roughness etc, when boring S45C steel under various cutting conditions. The chatter vibration occurs at the tool overhang of L/D=6 but does not occur at L/D=8, where has the highest damping ratio.

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The purpose of this research is to develop a next generation manufacturing process having both advantages of ultra-precision milling and grinding. In the manufacturing process, various three dimensional machining technologies are necessary to produce the cutting tool which features eight rotating monocrystalline diamond blades. Technologies are applied to fabricate edges, ridges, radius of the tips and height differences of the blades, within 10nm accuracy. Usually, two sets of cast iron plate are necessary for on-machine shaping of the blades. However, this time a fabrication technology using a double-face-incline cast iron plate has been developed. In the paper, principle and results of the new fabrication technology will be reported.

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Demands for sub-meso scale devices from millimeters to sub-millimeter in size such as micro engines, medical devices for minimally invasive treatment and Lab-on-a-chip are rapidly growing. However, currently we have no effective method of manufacturing these devices. We must manufacture ultra fine tools to realize sub-meso scale precision machining. Taking the ability of manufacturing three dimensional structures of various materials into account we consider that mechanical machine is preferable for fabrication of sub-meso scale devices. In this paper, we present the new method of manufacturing ultra fine diamond tools using photolithography process. This proposed method has advantages of high precision, volume production and thus, low cost. Etching of diamond was achieved by a reactive ion etching system (RIE) using O₂ gas or O₂ and CF₄ gas mixture. We derived the optimum recipe of diamond etching to manufacture ultra fine tools. The manufactured tools successfully pattern glass.

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The authors have proposed a new coolant method for machining by using the micro bubble coolant where the diameter of the bubble is 10-20 micrometer. A simple and inexpensive micro bubble generator is manufactured which can be applied to turning operation. The results indicate that the developed generator generates the micro bubbles stably and a large number of micro bubbles are present in the coolant supply from the nozzle outlet. From the turning test using the micro bubble coolant method on S45C steel and aluminum alloy, it is found that this method has effect of improving the tool life and the machined workpiece surface.

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To improve grinding coolant utilization efficiency, a new coolant supply method using a coolant flow guided flexible sheet was developed by authors. By this method, all the coolant supplied from a nozzle outlet can be exactly and immediately directed to a grinding point, because the coolant flow guided flexible sheet made of a thin sheet material is attracted to a wheel surface automatically, resulting in keeping the coolant flowing between the wheel surface and the sheet. In this study, in order to investigate an application of this method to high-speed grinding, the characteristic of a winding coolant on the grinding wheel surface under high wheel speed was investigated experimentally. It was clarified that the coolant was easily supplied to a grinding point in the high wheel speed of Vs=80m/s even with a small coolant pump.

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An MQL (Eco friendly) cutting process faces a big problem that most of produced chips remain on a working table and work piece because it has less capability to wash away produced chips. In order to solve this problem, a chip suction tool is suggested. To suction the chips stably, the chips is necessary to be broken into small pieces. In this study, effects of a chip control plate equipped with tool on chip breakage are investigated in turning process. It was found that the chip control plate can make a length of chip shorten and make a curl radius decrease.

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The paper deals with the effects of consistency of discharged mixture of liquid lubricant and compressed air for MQL (minimum quantity lubrication) on drilling. In MQL process, consistency of mixture of lubricant critically effects on its tool life and accuracy of the hole. However, it is very difficult to detect discharged mixture because of its quite few quantity and high speed.
In this study, at first, the relation of consumed quantity of lubricant and discharged amount from the mixing device was studied. Then measuring system for mixture sprayed with MQL on drilling was developed with optical dispersion detection principle. Results obtained were as follows.(a) Amount of mixture was practically measured at the cutting point of a drill. (b) Output signals from optical sensor was almost linear under 300ml/h discharged. And inclination was different at 40ml/h. (c) Average of signals output was not affected by discharged pattern. (d) Light source by luminous diode with visible ray made it possible to see the mixture directory.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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This research aims to realize the biped walking operation by creating the tele-existence between an operator (master) and a robot (slave) using bilateral control method. The bilateral control signals consist of the signal produced by operator′s walking operation and the signal of the reaction force of robot received from the floor. In this paper the new mechanism especially designed for harmonizing the operator′s motion and the robot′s control is introduced and verified of its stability of the control operation.

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[in Japanese]

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Recently, collaborative simulation environment is needed in the mechatoronics product design. In this research, a collaborative simulation environment is proposed using HLA (High Level Architecture) which is the IEEE standard of a distributed simulation. In this report, systematic sensor and actuator modeling for this collaborative simulation is proposed using object-orientation. This technique is applied to the design of power window system using a control system simulator and a 3D CAD kinematics simulator.

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In reinforcement learning, construction method of state-space influenced the capacity of learning. Fuzzy-ART is an incremental state-space construction method. It classifies an encountered state into an existed category. If the state does not belong to any category it makes a new category. The number of categories increases monotonically as more tasks are learned. It was necessary to prevent the redundant increase of the categories when many tasks had to be learned. We proposed a state-space construction method based on state value. It divides the important area of state-space into a lot of categories, and casts away insignificant categories according to state value. We classified that proposed method was effective to improvement of reinforcement learning in case of path planning for multi-link robots.

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We have developed a spherical handheld input device for the robot. It is intended for non-technical users, rather than robotics experts, to send commands to the robot. The device has a 3D angular velocity sensor and three acceleration sensors. By reading output from these sensors, the computer can decode linear movements, "snap" movements, and oscillation movements initiated by the user. In this paper, we discuss mapping from device inputs to commands for robots. As an example, we tried to make a robot dance using thie device.

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This research aims at recognizing tableware by image processing and RF tag. Invisible mark made of photochromic material is added to the tableware. RF tag is also attached to the tableware. Utilizing amplitude of RF signal, the rough distance between tag and robot can be obtained, which enables knowing correspondence between tableware and ID code. The robot can know the radius of tableware from ID code, which is necessary for calculating tableware′s position by image processing of the mark.

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In the task of recycling wasted televisions, extraction of harmful capacitor parts from an electronic circuit board is inevitable. In order to robotize this task, it is necessary to recognize these parts by image processing. The problem of this task is that the size and the position of these parts are different from one board to another according to the product company, the age of product, the kind of product, etc. Moreover, it would be difficult to keep a lighting condition in a recycling factory, compared with a fabricating/assembling factory. In this research, after narrowing the candidates for capacitor parts by using a common template matching method, these candidates are classified further into two categories of capacitor parts and others by utilizing Support Vector Machine, which is one of the classifying methods in the artificial intelligence research area. This recognition was successfully carried out with almost 100% probability. This method has a merit of being robust against the lighting conditions.

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[in Japanese]

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[in Japanese]

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We are researching an algorithm of taking away objects on a belt conveyer by a robot arm. Recognition and position measurement of the objects are done by a unique method which is integrated a robot coordinate system and a camera coordinate system to the world coordinate system. We develop an easy object recognition method of the robot.

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[in Japanese]

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[in Japanese]

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This paper proposes impedance matching of receiver in intra-body communication. The receiver with one electrode touches to the skin only by the signal electrode, and the receiver with two electrodes touches to the skin by the signal electrode and ground electrode. As a result of experiment, the input impedance that maximizes power consumption is about 100 ohms in the receiver with one electrode, and is about 150 ohms in the receiver with two electrodes.

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Recently, a Magnetic Resonance Imaging (MRI) compatible surgical assist robot has been required for improving Quality of Life (QOL) after operation that means the prevention of recurrences and complications. In our laboratory, it is developed that a manipulator using a spherical ultrasonic motor (SUSM) allows surgeons to operate robots in the MRI environment. SUSM is an actuator that is possible to move with multi-degree of freedom and has a simple structure. Because of the strong magnetic field of MRI, it is difficult to use existing attitude sensor for SUSM. This research proposes a non-contact detection method by using reflected light intensity. The hierarchical neural network system was applied in the sensing system. We have confirmed the availability of the sensing using reflected light intensity.

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This paper describes an optimization of a driving-electrode-area ratio of a voltage-induction type electrostatic motor. The motor consists of a slider film and a stator film, in each of which inducing electrodes and driving electrodes are included. A driving voltage of a slider is generated by electrostatic induction between an inducing electrode of a slider and that of a stator. To obtain maximum thrust force per unit electrode area, a driving-electrode-area ratio to the whole electrodes should be optimized. We derived theoretical formula of thrust force, with which the optimized area ratio was decided. The experimental result of the ratio decided by utilizing an electrostatic motor with capacitances showed the good agreement with the analytical result.

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This paper reports on the development of an attachment mechanism that utilizes electrostatic force and differential pressure force for wall climbing robots. The mechanism, electrostatic suction film, consists of a pair of electrodes and an insulating film. Holding force of a prototype suction film was investigated. The results showed that differential pressure force, as well as electrostatic attraction force, increases at higher applied voltages. It was also shown that the suction film can generate holding force against a holed wall. A prototype wall-climbing robot was developed using electrostatic suction films that could stably climb up an insulated conductive wall.

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In this paper, a finishing robot is proposed for NC machined PET bottle blow molds. The robot delicately removes surface cusps with about 0.3 mm height on a mold by using a ball-end abrasive tool. In order to consider the application limit of the robot, we first evaluate the backlash which causes the position inaccuracy at the tip of the abrasive tool, through a simple force control experiment. The relation between the polishing force error and manipulated variable is also measured and analyzed. From the discussed results, we show a few indispensable key points to apply the system concept to a smaller size mold with curved surface.

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This paper describes a remote control robot prototype system for millimeter-sized parts. The robot has parts of a grip and transportation for assembly parts. As a case example, buildup work of parts is done. This system is able to manipulate by a simple operation while seeing a screen. As a result, the system enables to easy a grip and transportation of distant parts. However, this system targets only simple work like the buildup work and is not suitable for complex work.

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This paper proposes a simulation system to remote control for mobile robots. A mobile robot carries the remotely control program and is operated with Graphical User Interface of operation Personal Computer on a network. At a present stage, a function which display of positions has a great difference between a movement in actual and that in a simulation system. So the function is improved the precision by the difference is reduced with the simulation.

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In many researches about obstacle avoidance, a vehicle′s shape is approximated by a circle and it can be treated as an omnidirectionaly movable point by expanding obstacles by radius of the circle. However, they have not dealt with the problem that a vehicle passes through a narrow space considering its shape. Therefore, we propose a new simple method for local obstacle avoidance. The vehicle′s shape is expressed by a polygon in a plane. We calculate a pair of a velocity and an angular velocity when each edge of a vehicle hits an obstacle. After this calculation is executed for all edges and all obstacles, we select a pair of a collision free velocity and angular velocity by which a vehicle is approaching the goal.

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