This paper deals with a new monitoring method of cutting state without dynamometers. The authors applied to examine the Speed Difference Square Method (SDSM) in this study. SDSM is a method to monitor the end milling process, and is based on the rotational speed of the milling spindle. The authors focused on the income and outgo of cutting power around the spindle, defined the SDSM index. In previous study of the authors, high correlation between the SDSM index and the cutting force by end face cutting on square end mill became clear. In this study, it was cleared that the ratio of cutting force of the thrust direction is greatly affect the correlation between cutting force and the SDSM index. And in plane cutting and contour cutting, the lower cutting of the ratio of cutting force of the thrust direction is suitable for monitoring of cutting state by the SDSM.
A laser-induced wet treatment was conducted on the stainless steel (SUS316L) surfaces. The disk-shaped samples were soaked in an aluminum nitrate solution and subsequently irradiated by a Yb fiber pulsed laser beam. The treated surfaces were observed with a scanning electron microscope, and analyzed with an energy dispersive X-ray spectrometer and X-ray diffraction. It was confirmed that the proposed treatment generated an Al- and O-rich layer, which was identified as Fe2+Al2O4 structure. The thickness of the generated layer increased with increasing the Al concentration of solution, increasing laser power and decreasing laser scan rate.
Laser shrink fitting for shaft coupling was developed as application of laser forming. The coupling of the pipe of stainless steel and bar of carbon steel is made by laser shrink fitting. A bar is inserted into a pipe, and the pipe surface of the bar-inserted-part is irradiated and heated by 1kw class laser. Metallographic structure of the laser irradiated part of the pipe and bar is not changed. The fitted part of the pipe is shrunk in both circumferential and axial direction. The residual stress on the surface of the fitted pipe is a compressive one in the circumferential and axial direction. The tensile strength of the fitted part is nearly equal to the tensile strength of base metal of stainless steel pipe.
Since Laser Sintering (LS) parts have high toughness and the high shape degree of freedom, it is beginning to be applied as a product. However its surface is rough that is approximately Ra 30μm. In the case of the parts which need better appearance, under the present circumstances, it is processing by machining and handwork such as sandpaper. However, in machining, it cannot respond to complicated shape, minute sections, and a free-form surface from the reasons of a tool diameter etc., and the processing by sandpaper is very inefficient. In this study, it proposed melting only the surface selectively using laser. The processing characteristic to polyamide LS parts was investigated and raster-scanning conditions were deduced. As a result of smoothing polyamide LS parts, roughness was able to be reduced to approximately Ra 0.4μm.
In regard with the precision positioning devices using the ball screw, its temperature rises during operation and this causes positioning error. In this paper, a ball screw temperature is decreased by cooling the nut from outside using two kinds of water jackets. This method is effective and very cheap. In case of the first jacket (D type), the water circulates along the double spiral grooves while in case of the second jacket (G type), cooling water moves going and returning inside the flow path along the longitudinal direction and the water circulates in the holes. By these two kind of jackets, the nut is cooled and at the same time the ball screw is cooled indirectly. The temperature of the ball screw and nut are measured by surface temperature measuring instrument and thermocouples. As a result, the followings are clarified. (1) D type is more effective than G type. (2) The ball screw temperature can be estimated by measuring the nut surface temperature.
Gait Recognition is recently evolving techniques by which we can recognize individuals by one's gait. There are two major approaches; silhouette-based and model-based. In Japan, a method based on GEI (Gait Energy Image), which is one of the silhouette-based approaches, is beginning to be used for forensic purposes. It is a problem, however, that person's silhouettes' variabilities due to conditions such as view angles, resolutions, frame-rates, and body regions used for analysis, and so on, sometimes lessen recognition reliability under the use of GEI method only. It is an urgent task to expand the ranges of application. In order to try to resolve the task, it could be valid to use several different approaches, including model-based ones. Previous studies of model-based methods can be divided in two types; manual and automated. However, it is a problem that manual methods require a person of special skills and experiences, and automated methods only can apply specific view condition, so it is required to develop finer model-based methods. Here, we proposed a novel model-based-like method based on feature points (resemble body joints) and local shape features around feature points. We examined error rates of the proposed method under various conditions of frame-rates, resolutions, and regions used in analysis, and compared them with those of GEI method. We found that the proposed method showed a little higher recognition rate than GEI one when captured from lateral direction and when upper body is used in analysis, and showed less dependency on low frame-rate conditions than GEI one when captured from lateral direction.
This paper proposes a software testing support system with the hardware failure simulation functions. In recent years, the high integration of the semiconductor device is advanced by the development of a smartphone and the tablet device. By such reason, a CD-SEM which is a semiconductor device tester using an electron beam needs high precisely and functionality. Software and concurrent development of the hardware are adopted to promote development of CD-SEM. However, a development delay of the software have been becoming big issue. One of the factors is that software test environment of large-scale software comprised of plural computers is insufficient. The software test support system was developed. It has the Real-time OS simulator and a hardware simulator which worked in a virtual machine. Furthermore, a hardware failure simulator is included in the system to make a hardware error stochastically. Herewith, the system works to prevent losing test case that a software engineer does not notice. At first, this article shows a software test support system using a hardware failure simulator. Then, it shows a result that applied the system to software development of CD-SEM.
Cutting speeds on the cutting edge of Ball-nose end mill vary from the bottom to the top of the cutting edge, thus the portion of the cutting edge that has a suitable cutting speed should be used in the finish milling process. This paper describes a procedure of generation of surface element groups that can be machined by the high performance portion of cutting edge in the finish milling process. For this purpose, performance values of cutting points on the cutting edge are proposed. The tool attitude to the surface element is evaluated by the ratio of the area machined by the high performance portion of cutting edge based on proposed performance values. The tool attitude having maximum area of the surface elements that can be machined with the high performance is derived, and a set of surface elements that can be machined by the high performance portion of cutting edge for the tool attitude is obtained as the surface element groups.