The motion planning approach of a multi-fingered robot for carton flap folding operations has been newly developed. This approach considers the loci of the tool center point for carton flap folding operations. Also that considers the pushing or fixing points of the carton flap. This approach is calculated from the rotating angle for carton flap folding and the position of a robot finger tip in contact with the carton surface, using inverse kinematics. And this approach can be adapted to changes of a carton size or a folding position. When the carton flap is folded using this approach, the robot finger tip touches the carton surface without slipping and moves along circular continuous path. Therefore in case of the rectangular carton box folding, each robot finger moves in each 2.5-dimensional Cartesian frame. In this report, the proposed approach is verified using a prototype robot system. This system consists of two pairs of the robot fingers and rotating mechanism for carton paper. Each finger has a 3-DOF SCARA type robot and a 1-DOF linear motion system. The testing carton boxes can be folded to the desired shape.

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This paper deals with controlling feed rate for small circular motion on NC machine tools. Recently new machining methods using small circular interpolation with endmills or direct taps have been used for machining cylindrical holes or tapping. Accordingly, contouring accuracy is getting more important in the new method. Decision of feed rate that influences contouring accuracy is the most important and difficult. So far the maximum feed rate for circular motion is decided according to the normal acceleration constant rule. This rule is a good way to restrict errors due to difference of stiffness between two axes because the errors are mainly proportional to normal acceleration. In the case of small circles, the rule is of no service. That is why errors are increasing as angle speed increases even if normal acceleration is constant. Therefore, the new rule to decide feed rate for small circular motion is needed. This paper analyses what is related with the errors in case of small radii and proposes a new rule to decide feed rate for small circular motion.

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Reaction between cubic boron nitride(cBN) and metal has been studied in this paper. Cubic BN grains immersed in metal powders : iron, chromium, nickel, manganese and molybdenum were heated up to 1100°C in argon or vacuum. Hollows observed on the heated cBN grains reveals that cBN should react with metal. The shapes etched depend on the metal, the crystallographic polarity of the cBN surface and the oxygen remaining in the chamber. Nickel powder made particularly large and clear hollows.
Moreover, the reaction was applied to microprocessing of cBN. A polycrystalline cBN on which nickel thin films had been deposited was heated up to 1100°C in vacuum. Removing the films exposed discolored marks. Raman spectroscopy revealed that the discolored areas contain Ni₃B. The areas were easily turned to be shallow holes by lapping.

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This paper describes the evaluation of machining performance for the developed micro multi-edged tool and a prototype of new cutting device by using it for plane machining. This tool is like a grinding stone and consists of micro pyramidal hillocks, which are about a few hundred nanometers tall and formed on the wet anisotropic etching in the silicon fabrication process. Though it is expected to machine aluminum alloy, glass and so on, there is a problem that is the requirement of surface contact between a material and the tool in plane machining. The developed prototype of cutting device is equipped with a new mechanism to solve this problem. In the plane machining of Al-Mg alloy by using this device, the cutting performance of micro multi-edged tool has been evaluated and it has become clear that the tool has the machining performance as well as superfinishing by using an grinding stone with superfine grains.

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The pad with self generating porosity has newly been developed, which is made of the petroleum pitch and the salt grains. Polishing of a silicon wafer is conducted using a new pad which is immersed into the slurry of the ultra-dispersed super fine diamonds. It is found that the surface roughness of silicon wafer decreases drastically with the polishing time, in which the slurry of polycrystalline diamonds yields a rapid decrease of surface roughness rather than that of singlecrystalline diamonds. Experiments show that the developed pad has an excellent performance for polishing of the silicon wafer rather than the conventional vesicant polyurethane pad.

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This paper presents theoretical analysis and design method of a linear vibrational electric generator that converts kinetic energy of vibration into electricity. The generator is intended for applications such as supplying electricity to sensors or small information devices that must function without batteries for a long period of time. The generator is modeled as a one-degree-of-freedom vibration system. It is shown that the maximum output is attained when the generator is vibrating at its resonant frequency and at its mechanically movable maximum amplitude. The vibration amplitude is controlled by changing the electro-mechanical damping of the vibration system. The experimental system consists of three stationary generator coils and a moving permanent magnet unit suspended by leaf springs. A micro controller monitors the generator output and changes the connection of the generator coils to adjust the electro-mechanical damping to maximize the generator output. This system generated power of 100mW with 29% efficiency when external vibration of 6Hz with 5mm(p-p) amplitude was applied.

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The surface roughness decreases down to the minimum just after start of plunge grinding with a super-soft grade resinoid bond wheel, of which bonding material is prepared by the interaction of polyvinyl alcohol and thermosetting plastics. In this paper, the grinding method with the resinoid bond wheel is investigated for the finest surface finish of workpiece, based on such minimizing phenomenon of surface roughness. Main conclusions obtained in this paper are as follows : (1) The finest surface finish is obtained by spark-out grinding operation starting just at the moment on which the surface roughness of workpiece decreases down to the minimum. (2) The surface finish by this grinding operation decreases with decreasing the initial surface roughness, but the decrease in surface roughness during the spark-out grinding process increases with increasing initial surface roughness. (3) The repetition of this grinding operation without dressing makes the surface finish smaller than that by a general grinding operation with larger depth of cut before spark-out grinding.

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A new non-circle turning machine has been developed to obtain the profile which consists of four undulations in the cross sectional profile for automobile piston. The developed displacement enlargement mechanism, which has the designed resonant frequencies with 2 degrees-of-freedom vibration system, vibrates synchronizing with spindle rotation of an NC lathe. This mechanism is driven by PZT electric device, which has not enough elongation originally, exciting the representative point of the beam support constrained on the tool base. Two resonant frequencies are designed so that the target profile is machined to realize four undulations for a circumference. The developed lathe realized the spindle revolution of 870rpm that exceeds the copy lathe, which is used for the ordinary piston machining, seldom exceeds the maximum revolution of 800rpm because of the limitation of dynamic characteristics depending on stylus follower. Although there are various NC lathes equipped additional axis and/or linear motor to solve this problem, these kinds of machines are not suitable for mass-production but these should be used for flexible manufacturing. On the contrary, the developed turning lathe machine is so simple that only the specific spindle revolution is acceptable and suitable for mass-production. Experimental results of no-circle turning showed the profile deviations for various non-circle targets settled within 7μm compared with the conventional profile tolerance of 10μm in the case of profile amplitude 350μm.

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The study deals with the creation of ultraprecision microgrooves using non-rotational diamond cutting tools with angle of 90 degrees, which are mounted on an ultraprecision machining center. Machining experiments of micro grooves were conducted to find the optimal value of cutting speed, depth of cut, rake angle, changing the cutting speed from 1mm/min to 200mm/min, the depth of cut from 0.1m to 10m and the rake angle from -5 degrees to 30 degrees. Workpieces were machined with the cutting tool submerged in the cutting fluid to know the influence of cutting fluid supply method. From the experimental results, the adequate cutting condition is obtained such as the rake angle of 10 degrees to 20 degrees, the finish cutting speed of 1mm/min and the depth of cut in rough cut and finish cut of 1m and 0.5m respectively. As the cutting fluid supply method, workpiece submerged in the cutting fluid is effective. Using the cutting condition, fine V-shaped microgrooves are obtained in various materials. In addition, frontlight optical plate and micro Fresnel lens with the designed micro grooves were designed and manufactured by non-rotational diamond cutting method. As a result, it is also found that the non-rotational diamond cutting method enables to accurately and neatly manufacture microgrooves without any burr generation.

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A structural design was proposed in our previous study for a fault tolerant steer-by-wire (SBW) system consisting of a principal SBW, a standby SBW and a mechanical backup possibly with a power assist feature. The authors used fault trees, minimal cut sets, and minimal path sets to derive an operation procedure. The present paper converts this operation procedure into a Markov transition diagram where each state represents either a normal SBW, or a partially degraded or a completely failed SBW. The system reliability is quantified in terms of the state probabilities calculated from a numerical integration of the Markov diagram specified by component failure rates. It turns out that the SBW design demonstrates a considerably high reliability through the introduction of mechanical backup. The power assist, however, is rarely expected for the mechanical backup mode. This mode can be reduced by ECU reliability improvement.

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The application of magnesium alloys to various products has been spreading. In this study, a laser forming of magnesium alloy plate was focused on. This paper describes the plastic bending properties and the deformation mechanism of magnesium alloy plate (AZ31) in CO₂ laser forming. In order to investigate the characteristics in the laser forming of magnesium alloy plate, the experiments were carried out under the various conditions and the bending angle and the temperature of workpiece were measured by use of a laser displacement sensor and thermo couples, respectively. The results were discussed comparing with the results of stainless steel plate (SUS304). Based on the experimental results, it was found that the bending angle greatly depended on the surface temperature. The bending deformation increased with an increase of the laser power and the repetition of the heating-cooling cycle. The bending angle of the plate continued to increase while alternately repeating an upper and lower bend. The upper side deformation was larger than the reverse side.

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The purpose of our study is to find a means of putting away clean laundry using a robot. This paper presents a method of spreading out and sorting crumpled laundry by dual manipulators and image processing. Because the shape of cloth tends to change in various ways depending on the situation, it is difficult for robot hands to spread out and sort laundry. For this reason, we propose a method of grasping the lowest points of laundry and changing the grasping points several times for spreading and sorting laundry. Laundry can be categorized to a small number of shapes, and this makes it easy for robot to be recognized. Furthermore, recognition of the shapes of laundry during the spreading process allows more accurate sorting. Using the manipulators and image processing eight kinds of laundry could be spread out and sorted successfully. The effectiveness of the proposed method is shown through experimental results.

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In order to assess the cutting performance of the scissors, we must predict the cutting force acting on fingers when we use the scissors. The total force acting on scissors is the sum of the load to cut the object and the blade friction load. The former consists of the loads to shear the object and to bend slightly it, both of which are acting together on the fingers by the lever mechanism through the rotation center connecting two blades as the fulcrum. We have developed and examined the prediction system of the total cutting force. With regard to three kinds of scissors, we have got the correlation coefficient greater than 0.9 between the predicted values and the experimental ones.

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The measurement error due to the optical system in a profile-measuring machine is evaluated experimentally for an inner groove fabricated in a circular hole. In this report, the method for measuring the groove fabricated on a plane surface is used, because it is difficult to produce a precise groove inside the circular hole. Even in this case, it is difficult to fabricate a groove within an error of±0.1μm. Then, a groove composed of a middle plate and two knife-edge plates set on both sides of the middle plate is developed. The groove depth can be changed from 0 to 300μm by moving the knife-edge plates back and forth using the developed groove. Furthermore, the groove width can be changed from 0.5 to 3.0mm by changing the middle plate. The measurement error of the optical profile-measuring machine can be evaluated within an error of±0.1μm using the developed groove.

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