In this paper we discuss the influence of electrolyzed oxidizing water (EO water) on the surface of Permalloy 45. First, we threw light on the etching efficiency of NaCl EO water and Na2SO4 EO water on the surface of Permalloy 45 bycomparing it with the etching efficiency of soaking in HCl solution and H2SO4 solution. The comparative study showed that as for the etching efficiency on Permalloy 45, NaCl EO water and Na2SO4 EO water was superior to HCl solution and H2SO4 solution. Also, EO water can process an etching equally to each composition elements of Permaooly 45 compared with chemicals. Next, by analyzing the surface, we made it clear that the influence which NaCl EO water and Na2SO4 EO water exerts on the chemical composition in the surface of Permalloy 45. The results showed that EO water does not have a bad influence on the chemical composition of Permalloy 45. By this study, we got the suggestion that EO water can be applied to the surface processing of Permalloy 45.
Wheel loading is one of the serious problems on high efficiency grinding, creep feed grinding, and grinding using fine grain. Some researches ware experimentally demonstrated ultrasonically excited grinding fluid which includes cavitation bubble, prevent the loading and improve surface integrity. In this study, simple comb-form exciter has been developed. It is inserted between the fluid supplying nozzle and grinding point. Influence of distance between exciter and grinding point has been investigated to optimize distance. The performance of exciter has been investigated through grinding hard-to-grind material with WA grinding wheel. As a result on aluminum alloy and SUS, influences improvement of surface integrity, reduction of grinding force and suppression of grinding force escalation, with ultrasonically excited fluid generated by the comb-form exciter are confirmed. The performance of exciter has been investigated also for ferrous material which known as easy-to-grind material. As a result, surface integrity improvement which influenced by ultrasonically excited fluid is confirmed also for ferrous material.
This paper discusses the results of investigating the volume of craters removed, protruded, and resolidifying etc. by single pulse discharge, and the effects of the difference in the crater shape on these volumes calculated by using the method of stacking cross sectional shapes of craters. First, the stacking error of the volume calculated by this method was studied by comparison with mathematical approximation, the volume of a crater whose shape is known was created, and the volume was calculated. The results showed that the calculated volume error can be controlled to below 2% by setting the slice width below 10μm. Next, we calculated the various volumes created by single pulse discharge by mathematical approximation, 3D-CAD, and stacked cross-sectional shape calculation method, and the results showed large errors in the calculation of the volumes by mathematical approximation and 3D-CAD. Finally, we compared the various volumes of craters with different shapes calculated volume by the stacked cross-sectional shape calculation method, and obtained the following results; 1)crater volume is influenced by the crater shape, 2)more than 50% of molten crater remains on the workpiece surface due to the discharge arc column.
The study deals with development of the inclined planetary milling spindle unit. Although CFRP and composite materials are known as difficult-to-cut-material due to their abrasive action for intensive wear of cutting tools, they are widely used as structural materials in recent aviation industries. The orbital drilling technique is one of possible solutions for making hole drilling faster and more effective in aviation assembling process. However the orbital drilling has some drawbacks such as vibration and cutting with 0 velocity point. In order to improve machinability of the orbital drilling, the authors propose an inclined planetary milling system which is inspired by the oblique and helical milling by 5-DOF machining center to avoid cutting with 0 velocity point. Eccentricity is realized by a few degrees inclination of tool rotation spindle and it can reduce mechanical vibration. In the study, analysis of geometric machining model of the inclined planetary milling has been considered. A prototype of the spindle unit was developed and actual drilling experiment were carried out. Comprehensive observation revealed that vibration, machining force, burrs and delaminations are greatly improved in comparison with the orbital one. This inclined planetary milling method has some advantages and its practicality and usability has been demonstrated.
Small lenses are one of the most important elements in digital devices such as mobile phones with cameras. In order to minimize the machining error of aspheric lens molds with high form accuracy, on-machine measurement of the lens mold shape is important. However, they require large field of view of mm order in diameter, robustness against vibrational noises from environment, short tact time, and compact body for on-machine measurements. We developed a Fizeau-type interferometer with wide field of view. The interferometer has small laser spot of 2.5μm in diameter, which scans over the 10mm x 8mm of observation area. With the use of transparent reference plates set over the concave of the lens mold, fringe patterns of lens mold with about 1.5mm in diameter was successfully observed in 80 seconds. This interferometer is also designed in a compact size.
This paper proposes a novel practical path planning framework for autonomous parking in cluttered environments with narrow passages. The proposed global path planning method is based on an improved Fast Marching algorithm to generate a path with considering the moving forward and backward maneuver. In addition, the Support Vector Machine is utilized to provide the maximum clearance from obstacles considering the vehicle dynamics to provide a safe and feasible path. We also propose a local path planning for obstacle avoidance and tracking global path. The method is implemented on an autonomous vehicle platform and validated in the real environment with narrow passages.
A multiple optical paths grating projector for high-speed shape measurement is proposed in this paper. The prototype projector has three optical paths produced with half mirrors. A grating plate and an LED device are placed on the end of each optical path. The image of the grating plate is projected onto the object by a focal lens when the corresponding LED lights up. Three grating plates are placed on the respective optical path. The positions of the grating plates are adjusted in such a way that the projected grating patterns are shifted at intervals of 1/3 periods of the grating pitch. This projector can shift the phase of the projected grating patterns quickly with switching the position of lighted LED. The evaluated maximum response speed of phase shifting using this projector is 600 kHz. High-speed shape measurements are performed with a high-speed camera and this projector. As experimental results, shape measurement of a milk crown was performed in 5 kHz with phase-shifting speed of 15 kHz and shape measurement of a rotating fan was performed in 10 kHz with phase-shifting speed of 30 kHz. It was demonstrated that the proposed multiple optical paths grating projector was available for high-speed shape measurement.
This paper presents a real time control method of transportation robot in a production line for its throughput improvement. The robot transports more than thousand works among the processes by one-piece. Furthermore, there are and no buffers between processes in the production line. In this buffer-less production line, blocking phenomenon that a work cannot be transported if there is no vacancy in next process is occurred. For improving throughput of the equipment, both cycle transportation time reduction of the robot and workaround plan for transportation blocking avoidance are required. The focuses of this paper are the throughput balance of multiple processes and the work selection from works waiting same process. This approach realizes a new transportation control system with transported volume balance and shortest path selection. In conclusion, the developed system improves more than 7% throughput from a dispatch method and reaches a high throughput such as optimized by full-search method in 0.2 second calculation time.