Wavelength scanning interferometry allows the simultaneous measurement of surface shape and optical thickness variation of a transparent object consisting of several parallel surfaces. It is observed that multiple fringe patterns overlap each other in the interference image of such an object. When the wavelength is scanned, the phases of these fringe patterns change with different frequencies. Therefore they can be detected by a phase-shifting technique which is designed for an arbitrary order of harmonic signal. However, the noise caused by signal frequency detuning and other nonlinearities makes it difficult to obtain reliable results. In this paper, a new 2N-1 sample algorithm for the detection of arbitrary order of harmonics is derived. The new algorithm suppresses the effect of signal frequency detuning as well as the multiple-beam interference noise. From the experimental results, it is shown that the new algorithm can measure the object consisting of three reflecting surfaces with an uncertainty λ/10 in a Fizeau interferometer.

View full abstract

Anti-vibration units have been developed to realize micro-vibration circumstance. Recently, the anti-vibration units with the piezo-elements have been widely developed. In order to improve the transmissibility from the floor vibration to the isolated table vibration, 2 degrees-of-freedom mechanical isolated apparatus has been applied in the production field. In its apparatus, the piezo-element and the acceleration sensor were normally installed. However, in this paper, the voice coil motor is newly implemented and the velocity sensors instead of the acceleration sensors are used. Firstly, the mechanical model is shown and the complete isolated condition is derived under the condition of the full-state feedback. Secondly, it is shown that its condition relates the result of zeroing control theory and also coincides with the known feedforward control from the floor vibration. Finally, dynamics of actuators and that of velocity sensors are reasonably set to examine both the performance concerned with the transmissibility and the engineering possibility. As a result, the driving displacement of piezo element and the driving force of VCM are confined within the limits.

View full abstract

Most optical stylus sensors composed of laser diode as a light source and objective lens are troubled with signal noise when being traversed over machined engineering surfaces. Its main causes are irregularity and asymmetry of reflected light intensity distribution due to speckle noise inevitably included in the reflected light and geometrical inclination of sample surface. The optical compensation method of reducing the speckle noise was developed in the previous report. This paper describes the effect of sample surface inclination on the detected displacement signal and reveals that such component can be corrected by using the same optical system as the speckle noise reduction system. Experimental verification of the total error compensation propriety is also presented.

View full abstract

In a software servo system, reference input time interval and sampling time interval are two important control parameters. In this paper, these two control parameters are adjusted to achieve high performance contour control along a circle drawing and its performance has been analyzed through mathematical models concerning two critical control performance criteria, namely decrease in radius and surface roughness. Further, validity of the analytical equations has been confirmed through experiments in an actual software servo system.

View full abstract

Evaluation of the uncertainty for the measurement of the low thermal expansion glass gauge blocks by optical interferometry is presented. The thermal expansion coefficient of the evaluated glass gauge block is about 140 times smaller than that of the steel gauge block. We mainly evaluated the uncertainty of the wringing and the measurement of the excess fraction part of interference fringe order. The combined standard uncertainty of the glass gauge block is about 36 nm in 1000 mm gauge block. This value of uncertainty is almost half of that of the steel gauge blocks.

View full abstract

This paper describes development of a three somites earthworm type mobile inspection robot which is able to move in long and small diameter pipes. We have many small diameter pipes which are gas or water pipes for individual or corporate houses and boilers or hot water pipes for industries. They are settled in the ground horizontally or in the narrow spaces vertically and some of them are covered by casings or hard heat insulating matters. It is very difficult to inspect from out of the pipes. If we can insert a mobile inspection robot into the pipes from the suitable position, we are easy to inspect the pipes. Authors fabricated a three somites earthworm type mobile inspection robot in which we use three rubber bellows as pneumatic actuators. Sixteen rubber friction rings are used to get friction force between pneumatic actuators and the pipes. The electromagnetic valves and air-feeding tubes for the pneumatic actuators are carried on trolleys in order to decrease friction force between the pipes and them. The fabricated three somites earthworm type mobile inspection robot can move in a horizontal pipe which is 78 mm in inner diameter and 100 m long, and in a vertical pipe carrying a load that is equivalent to the air-feeding tube of 26 m length. Consequently, the inspection robot was confirmed to move in the long and small diameter pipes.

View full abstract

It has become popular to obtain technical information on the manufacturing field from the distributed Web sites and engineers are using them for operation planning and trouble recovery based in the process of Q&A using search engines. This paper takes an example for arc welding and discusses an effective method by linking them to organize a virtually integrated information base on the Internet. For the purpose, an arc welding case data format is proposed as an ordered set of technical data. It is derived from the WPS/PQR (Welding Procedure Specification and Procedure Qualification Record), which are widely used for the certification. The proposed formulation is examined by typical inquiry examples and evaluated feasible utilizing UML, XML and other related Web service technologies.

View full abstract

In order to evaluate the grinding stone performance, it is necessary to consider the influence of cutting edge shape and frank face area for a grain. For example, the crack depth for cutting glass materials will be affected by these characteristics in small depth of cut. Though the cutting edge shape is formed by crossing of the rake face and the frank face for a grain, this line is often complicated. Then, complication of edge shape was expressed quantitatively by the fractal dimension in previous study. In this study, the fractal dimension of diamond grain edge and the frank face size of grain tip were discussed how to influence the crack depth of glass. The fractal dimension of diamond grain edges ranged from 1.04 to 1.38. This means that the edge shape of the individual diamond differ largely on complication. From results of scratch test using single diamond grains, positive correlation appeared between the ratio of fractal dimension and frank face size for a grain edge and the crack depth of glass. That is, when edge shape becomes more simple and frank face size becomes larger, the crack depth of glass increases in small depth of cut.

View full abstract

We developed a new visualization method that enables to observe the chip ejection process continuously in dry drilling. The work piece material is inserted to the clear tube then the drill removes only the workpiece as a chip. This process was observed by a high-speed camera from the outside of the clear tube. The diameter of the workpiece and the inner diameter of the clear tube is almost same size and the drill diameter is smaller than them 0.1mm. Comparing three kinds of drills that have different helix angles 15, 30, 40 degrees, it was observed that the chip ejection speed using 40 degrees helix drill is the fastest in these drills even though the ejection route along the flute is the longest. To confirm the effect of the roughness of the inner surface of the hole to the chip ejection process, conventional dry drilling of aluminum alloy was also carried on. It was found that the segmented chip is formed if high helix angle drill is used but the chip jam doesn't occurred until the hole depth reaches to three times of drill diameter. As a result, a high helix angle drill is suitable for the dry drilling of aluminum alloy.

View full abstract

EEM is a surface removal process in the mixture fluid of ultrapure water and silica powder particles. In this study, in order to clarify the influence of the mixture on the morphological change resulting from the etching in the fluid, the surface morphology and the etching on Si(001) surface after immersion in the mixture fluid were examined in detail. The etching on Si(001) surface in the fluid scarcely proceeds for 70 hours, although the etching in ultrapure water proceeds constantly. The surface morphology after immersion in the fluid seems to be the same as that before immersion from the result of the power spectral density (PSD) analysis. From these results, surface morphology on Si(001) in the fluid was found to be preserved.

View full abstract

This paper proposes a mathematical model of a feed drive system which consists of an AC servo motor and linear ball guides. Structural and viscous damping of the mechanical system, Coulomb friction of the bearings and torque saturation characteristics of the motor are introduced into the mathematical model. Identification method of the parameters for the proposed model is also discussed. Various responses such as frequency response, step response, circular motion and corner tracking motion were simulated by the proposed model. Experimental works were also carried out in order to compare with the simulation results. It was found that the actual motor torque curves of the feed drive system were well expressed by the simulation model, and the shape and height of quadrant glitches of the circular trajectory were simulated accurately. In addition, the relationship between the centripetal acceleration of circular motion and the heights of quadrant glitch were investigated.

View full abstract

The 5-axis control machining has a lot of advantages in the machining of complex shapes such as impeller and propeller, also in the rational use of cutting tools, and so on. However, the wide use of 5-axis control machining is very difficult because CAM software which can calculate the cutter location data while considering the tool interference problem is nonexistence. We have proposed the tool path generation method for 5-axis control machining using an original configuration space, and shown that a smooth and interference-free tool path can be generated based on the selected machining strategy. However, the conventional method generates cutter locations in each path by interpolating the calculated local tool attitudes at several cutting points. Therefore, generated paths were not ideal when evaluating the entire path due to a large amount of redundant movements. In this study, the initial cutter location and attitudes after interference avoidance are decided while referring to all of the configuration space information at several cutting points. The devised method can generate the best cutter location with the least amount of the change in tool attitude. Finally, the method is implemented to the original CAM software for 5-axis control machining. As a result, it is experimentally found that the system enables the optimum 5-axis control machining.

View full abstract

A diamond pellets grinding (DPG) is surface-machining method using a DPG plate. The DPG plate has many diamond pellets with regularity. DPG efficiency depends on a grinding distance between the DPG plate and the work-piece. The grinding distance makes a change caused by the layout of many pellets in the DPG plate. Therefore, we have to examine the grinding conditions from the viewpoint of the grinding distance when we design the layout of many diamond pellets in the DPG plate. This study aims to find the optimum conditions in the DPG. This paper presents the calculation method of the grinding distance. Moreover, this paper discusses the results of processing efficiency and accuracy. Especially, a genetic algorithm is used as the optimization method for decreasing the deviation of the grinding distance at the ground work-piece. This optimized results show that the genetic algorithm can design the layout of many diamond pellets in the DPG plate for which the deviation of the grinding distance is remarkably small.

View full abstract

The object in this study is to establish “Mild Cooling Air Machining Method” that has a cooling effect equal to conventional cooling air machining. The basic way of thinking for it is that removing cutting heat by two ways: One of them is removed by about −5°C mild cooling air. The other is removed by tool side which is applied removing cutting heat contrivance. In this paper, one of removing heat ways: from tool is noticed. And relationships between removed heat and tip temperature, tip wear, machined surface roughness are considered. After that, thermal conductivity analysis about removing heat effect from tool side is also tested, and compared with an observation result. As collect, following results are obtained, 1) When cutting heat is removed from tool side, tip temperature drops, and tip flank wear width and ten point average roughness are reduced. And tip wear and machined surface roughness are improved by increasing the removed heat. 2) It is indicated that predicting whole tendency is possible by using thermal conductivity analysis

View full abstract

For the purpose of machining an ultra high frequency quartz resonator, we study making of quartz wafer with uniform thickness by Plasma CVM. In this paper, it was to examine the relationship between machining characteristics and machining parameters (composition of reactive gas, RF power density, machining gap, rotation speed of electrode, etc.) in order to form an optimum shape of the unit removal spot. Then, correction of thickness variation of quartz wafer by the numerically controlled plasma CVM was carried out by utilizing the rotary electrode. Fabricated quartz wafer had small thickness variation (PV 67nm, and standard deviation 16nm), and total processing time was only 94 seconds.

View full abstract