The paper aims to show the possibility of the actuation and the measurement of mechanical step displacements of 10 picometers or less than using a designed piezoelectric (PZT) driving stage and heterodyne interferometry. In our experiment, we use a designed parallel spring stage made by LEX-ZERO (low thermal expansion material) with a high-voltage PZT actuator (0 to -1000 V) to generate mechanical displacements with a step of 10 pm or less than. For a measurement system to achieve these picometer-order displacement measurements, the proposed single phase-locked loop [1] developed on a field-programmable gate array (FPGA) platform aiming to high-resolution phase measurement is used, and a modified heterodyne interferometer with two spatially separated beams is established. Both the actuation and measurement systems are located inside a vacuum chamber for suppressing environmental fluctuations that impact the measurement results. In this paper, the design, instrumentation, and experimental results are discussed. Reference [1] T-D Nguyen, et al., Direct phase determination using phase lock loop for heterodyne displacement-measuring interferometers, Proceedings of Photonic Asia Conference, 2018.

We have established the original methodology that enable to observe atomic orderings and arrangements of surfaces with arbitrary directions on three-dimensionally (3D) figured structures, by developing diffraction and microscopy techniques. An original technique, namely, the directly and quantitatively viewing of the side- and facet-surfaces in atomic scale using reflection high-energy electron diffraction (RHEED) and scanning tunneling microscope (STM), can feedback to the determination of process parameters in the etching procedure, and realize the atomically-ordered 3D surfaces. RHEED and STM prove atomically-reconstructed Si{100}2x1, {110}16x2, and {111}7x7 side- and facet-surfaces.

The purpose of this research is to develop a patient movement support system based on image processing. Although there are many types of fall preventive movement sensor using in the hospital, these sensors have problems that are malfunction alert, alert after the accident and so on. Therefore, in this research, we are developing a system to continuously monitor the condition of the patient by using a distance sensor. In this report, we describe the development of a function that detects the third-party such as nurse or visitors. Moreover, we developed a function that can reduce a malfunction of patient recognition caused by intrusion.

The five-axis machine tools have been increasingly used among all fields of manufacturing, and the research related to geometric errors is the most non-negligible subject of five-axis machining accuracy. According to the shape generation theory, the geometric error model is established through the D-H matrix of each geometric error to achieve the coordinate transformation. In this study, the authors propose a modification of the previous geometric error model, through the additional workpiece coordinate transformation. The simulation results of cubic-machining test show that it is necessary to consider the workpiece coordinate system to make the proper error reflection onto the simulated machining surface.

In recent years, in addition to high-speed and high-precision machining, it has become important that the machined surface has high quality. However, the evaluation method for the surface quality is not fixed, and it is usually evaluated by comparative photographs or appearance of the machined surface. In this study, we propose a method to evaluate the surface quality based on the average and the variation of the amount of reflected laser light. By this method, surface quality has been evaluated for workpieces machined with different pick feeds, and the relationship between surface quality and surface roughness has been studied.

This paper investigates the mechanical and electrical power losses in the feed drive systems driven by an AC servo motor and a ball-screw. The electric power consumption of the servo motor has been measured for several velocities and loads and the efficiency map has been drawn. The velocity dependent power consumption of each component; bearings, ball-screw nut, and linear guides has also been identified. Four ball-screws differing for the lead and the preload have been tested. Finally it is clarified that the total power consumption of the system is determined as a balance of the mechanical and electrical power losses.

An altered layer is formed on the surface of single crystal diamond by FIB processing. In this study, we focus on the process of structural change of the work-affected layer by deep ultraviolet irradiation using micro-Raman spectroscopy. Etching of the work-affected layer is observed by irradiating deep ultraviolet rays in an oxygen atmosphere. It has been clarified that the oxygen concentration affects the etching rate. In the presentation, we will discuss the process of structural change of the work-affected layer by deep ultraviolet irradiation and the surface structure after etching.