This paper describes the vibration responses of a single carriage of linear roller guides. Excitation was conducted by an impulse hammer through a block fixed on the carriage and its response was detected by an accelerometer and a sound level meter. Both of acceleration and sound pressure were analyzed by an FFT analyzer. The resonance frequencies of four carriages were measured changing the number of roller inserted into the carriage as well as the mass of the block. From the experimental results, it is found that the resonance frequencies are dependent on the number of rollers. It is supposed from the experimental results that the number of rollers contacting with the race way of the carriage governs the resonant frequency. Then, the surface profile of the raceway of every carriage was measured by means of a surface profile measuring instrument with stylus method. It may be pointed out that there is a possibility of influencing of the surface profile of the race way on the resonance frequency of the carriage. If this impulse excitation is adopted for the inspection of the carriages, the straightness of the race way could be checked by measuring the resonance frequency.

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In two-dimensional(2D) space, the clothoid is a preferred trajectory curve because its curvature varies linearly with its curve length. However, in three-dimensional(3D) space, both curvature and torsion must be considered. This paper deals with path generation using linear curvature and torsion segments which can be considered a 3D extension of the 2D clothoid. In our study, the path segments are generated by solving the Frenet-Serret equation. In every path segment, its curvature and torsion varies linearly with its curve length. In order to obtain more free parameters, plural curve segments are connected in series to make a compound curve. The curve is used to connect two given points which may have given Frenet-Frame, curvature and torsion constraints. These curves are also used to construct a smooth transition passing through an arbitrary point sequence. The resultant path possesses C² as well as torsion continuity and matches all given Frenet-frame, curvature and torsion constraints at the given points.

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The recent progress of mid/ long-range laser scanners enables to capture large-scale point-clouds in short time. However, point-clouds typically contain many large noises and outliers, therefore, reliable smoothing methods are very important. Although the moving least-squares or the moving robust estimate is powerful smoothing tools, they are very time-consuming for large-scale point-clouds. In this paper, we propose a GPU-based method to accelerate the moving robust estimate. We implemented it on a GPU and evaluated its performance. The result shows that our GPU-based method is much faster than CPU-based smoothing, and it can be applied to large-scale point-clouds.

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A printed circuit board (PCB) is a laminated composite made of circuit and insulator layers. The PCB is heated in a furnace to mount electronic devices. This process is called a reflow process. The PCB deforms in the reflow process by gravity and thermal expansion difference of materials. The deformation does not disappear after the process by the viscoelastic property of the resin in the circuit and insulator layers. The viscoelastic property is measured and the deformation of the PCB after the reflow process is modeled by the micro mechanics of composites, the laminated composite theory and the viscoelastic model. A design optimization problem is defined so that the area ratios of copper in the circuit layers and the ratios of thickness increase in the insulator layers are determined to decrease the PCB deformation after the process. A penalty is introduced into the objective function so that the cost of design change is minimized. Because the consideration of the less design change results in some sets of local optimum values of design variables, a global optimization method is adopted. Several optimization examples clarify features of the optimum PCB designs. The validity of the optimum design is verified by an experiment.

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This paper presents a novel compensation approach for nonlinear properties in harmonic drive gearings, in order to improve the performance deterioration in the static/dynamic positioning caused by the nonlinear components in mechanism. In the compensation, a modified exact linearization method is applied in the model-based feedforward control manner, where a two-mass plant system with nonlinear components, i.e. friction, stiffness, and angular transmission error of the gearing, is mathematically modeled to ensure the linearization. The proposed approach has been adopted to a positioning controller and been verified by numerical simulations and experiments using a prototype of positioning device with harmonic drive gearing.

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This paper presents an on-machine surface profile measurement system for a large mirror to be used on a satellite. The system is constructed by fixing a long-stroke length gauge on a commercial rotary grinder which fabricates the mirror. The combination of the length gauge and the grinder automatically measures the profiles which can be used in compensation of profile error. Position and attitude misalignments of the length gauge induce significant errors to the profile measurement. Quantitative and efficient alignment methods are developed for the position and attitude of the length gauge. The constructed system, the developed alignment methods and profile measurement results are described.

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In this paper we discuss the influence of Na₂SO₄ EO water (electrolyzed oxidizing water) on the surface of oxygen-free copper. First, we threw light on the etching efficiency of Na₂SO₄ EO water on the surface of oxygen-free copper by comparing it with the etching efficiency of soaking in NaCl EO water or chemicals. The comparative study showed that as for the etching efficiency on oxygen-free copper, Na₂SO₄ EO water was superior to chemicals, while inferior to NaCl EO water. Next, we threw light on the influence of Na₂SO₄ EO water on the surface shape of oxygen-free copper by the SEM observations and AFM measurement. As the result, the effect of Na₂SO₄ EO water on oxygen-free copper, which made its surface coarse, turned out weaker than that of NaCl EO water. Lastly, by analyzing the surface, we made it clear that Na₂SO₄ EO water did not form foreign substances such as copper chloride which was formed when using NaCl EO water. Unlike NaCl EO water, Na₂SO₄ EO water can be utilized widely for surface washing or surface treatment of precision machine.

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Dies for injection molding parts such as key sheet and body of cellular phones require high quality surface finish in terms of both appearance and integrity. Manual finishing is an important for die manufacturing process, which decides the surface roughness of a die and affects the accuracy of its shape. However, manual polishing consumes several days to finish the die surface. Therefore, high precise die milling or grinding technique which achieves mirror surface finish is requires, in order to minimize polishing operation. In the previous report, ultrasonically diamond grindings realized mirror surface finish of die mold. It was confirmed that cutting edge truncation before grinding is necessary to obtain mirror surface. In this study, effect of depth of cutting edge truncation was considered to establish grinding parameters for mirror surface finish. Furthermore estimation method for determination of optimal truncation depth by measuring thrust force and torque during grinding was investigated.

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