This paper presents a design of the software platform and framework intended to develop and execute a decentralized autonomous system. The platform has the featured functions that sub-system can be transported on a distributed hardware environment, and functions of sub-system can be remade by joining different two sub-systems together and by separating a sub-system. By using the platform, system designer can easily construct the application that consists of sub-systems behaved as taking in functions of other sub-system and moving on network, if necessary. Furthermore, these functions can be performed by a sub-system remote from the sub-system to be transported, joined or separated. Improving capabilities of system implementation and maintenance can be expected by this remote execution. In this paper, the platform and framework developed in this study are described, then result of an example system implemented into the developed platform is reported for discussing usage and effectiveness of the platform.
This paper presents a new method to determine optimum cutting condition of a machine tool based on load frequency. Minimum cutting cost within machine tool in life cycle is estimated from depreciation differential cost between in predetermined and predicted life cycle of machine tool, labor fee and tool price. The predicated depreciation cost is calculated with the load frequency and the life cycle. Then, the cutting condition to make the cutting cost lowest is applied to next part to be produced. The method is proved to be effective to result in about 7 percent cutting cost reduction on the case studies in experiments and simulation.
Automatic adjustment of optical axis and focus for CD player optical pickup was achieved by developing undermentioned element technologies. (1) The optical axis inquiry method to look for the optical axis at all over and high speed was developed by changing the inquiry route automatically when the detector movement exceeds the permissible operation range. (2) Highly accurate adjustment method of the optical detector position was achieved by dividing adjustment process into rough adjustment and minuteness adjustment and by applying each specialized measurement algorithm respectively. (3) Focus adjustment method of the focus lens was developed by eliminating the influence of the signal disorder. (4) High accurate screw tightening method was developed by forecasting and correcting the displacement caused by screw tightening. These technologies were synthesized, and high accuracy automatic adjustment equipment for the optical axis and the focus was developed.
In order to correct the defects of the conventional ultraprecision tables, the ultraprecision table with a machined point control type was newly developed and the ductile mode cutting for brittle materials was achieved. The table which is subject to Abbe's principle in the vertical cutting direction consists of a piezoelectric actuator and a laser measuring system as the feedback sensor. In the horizontal feed direction it is moved by a DC servomotor and steel-belt. Its vertical positioning resolution is 5 nm, the straightness is 10 nm in the 100 mm stroke and the static rigidity is infinite by a PI-D control, but the dynamic rigidity is a little poor due to mechanical resonance. The silicon cutting test using this table shows a good result which can discriminate between the ductile mode cutting and brittle mode cutting by use of an AE sensor and cutting resistance ratio.
This paper presents a new position-based impedance control that can take account of a desired position in the force control, and gives a transformation technique from the position command to the torque command in order to apply the control to industrial robots with open architecture controller, or to implement it in computer simulations. Next, to determine a suitable compliance without trial and error, this paper introduces a new method that produces the desired time-varying compliance, giving the critical damping in contact with an object, by using informations on inertia and Jacobian matrices. Simulation results have shown that the proposed methods are very effective for realizing it in industrial robots and for deciding the desired compliance without any complicated tuning.
This paper concerns the problem of the fast and high accurate mass measurement under the conditions of floor vibration. In order to reduce the influence of floor vibration, a sensor which measures floor vibration is generally installed near the weighing sensor. The output signals from these two sensors are processed, and weighed mass is calculated. However, the dynamics of these two sensors are different in general, and the difference of the dynamics influences measurement accuracy. In order to improve the accuracy of mass measurement without losing the quickness, the authors apply the method of relative dynamic compensation to the problem, and propose two methods of mass measurement by using relative dynamic compensation. As a result, the feasibility of the methods is verified by experiment.
This report proposes a new method which can detect internal weld defect areas appearing in X-ray radiographic films, and verifies its efficiency using actual defect images. The method has robustness against noise and blurred defect images, because each pixel of image votes for an area decided by the direction of gradient vector of the pixel. And the method can classify the image into defective areas and indefective areas by thresholding the voted image. The results using actual images are as follows, (1) more than 90% defects in 125 images are detected, and (2) more than 85% of their characteristic defect shape are found.
Dimensional error measurement for stepped workpiece profiles has been achieved by a new proximity sensor using a pneumatic technique. Static analysis and simulation results were used in designing the sensor for application to a bench-type lathe. This sensor consists of three sensing nozzles and can continuously measure the dimensional error of a stepped workpiece by one of these three sensing nozzles in accordance with the computer programme. Any deviation in the distance between the sensing head and the workpiece surface results in a change in the sum of the outputs from the sensor. Comparison with the results obtained by a Universal Measuring Microscope shows the effectiveness of the new system in on-machine measurement.
An estimation method of energy flowing rate into a workpiece in surface grinding was discussed. The temperatureand its change in a workpiece were measured by a thermocouple insertion method. On the other hand, 3D temperature distribution and its change with grinding wheel travel were numerically analyzed by considering the thermocouple and hole for temperature measurement. Through the analysis the effects of hole diameter / depth on the temperature distribution and its change were precisely discussed. The larger hole diameter causes the higher temperature at the measuring point on the hole bottom. The deeper hole, in which a measuring position is near the ground surface, also causes the higher temperature. Thus the careless measurement and analysis of temperature cause the wide scatter of temperature. The energy flowing rates which were estimated based. on the analyzed temperature without considering a measuring hole were widely scattered and increased with hole diameter. The rates exceeded 100% for the large diameter hole. The estimated rate using the precise temperature analysis considering the effect of hole size I depth on temperature was little affected by the hole size, and the rate was estimated about fifty percent irrespective of hole size.
This paper describes an angled-convex-polishing apparatus for optical fiber endfaces, which is used for APC connectors (angled-physical-contact optical connectors), and its evaluation. This apparatus constructed utilizing an elastic-polishing-plate is driven in accordance with combined orbital and rotational motion. When a slanted angle of the ferrule endface was 8 degrees, the diameter of the ferrule endface wasranging from 1 to 2 mm, the Shore-hardness of the elastic-plate was Hs 70, and the polishing load was 200 gf/mm2, both the physical and optical performance obtained from an experimental study were as follows : An angled-convex radius on the ferrule endface was from 5.4 to 10.6 mm, a shift of the vertex on the convex surface from the optical fiber axis was less than 38.5lam, the withdrawal of the optical fiber endface from the ferrule endface was less than 0.046 μm, the backreflection was less than - 66 dB, and the insertion loss was less than 0.41 dB.
High speed grinding has long been considered one of the most effective methods for improving productivity of manufacturing lines. This study applies ultrahigh speed CBN grinding technology to develop a cam profile grinding machine capable of dramatically exceeding the machining efficiency of conventional cam grinders. This paper evaluates the characteristics of a chilled casting ground in experiments carried out with an ultrahigh speed surface grinding machine allowing operation at a wheel peripheral speed up to 200 m/s. An equation expressing the relationship between grinding force and grinding conditions : wheel peripheral speed, wheel depth of cut, and grinding wheel diameter, was developed. In addition, grinding power consumption was demonstrated to be independent of wheel peripheral speed, and to be defined only by grinding stock removal rate. Furthermore, the increase in wheel peripheral speed from 80 m/s to 200 m/s, both doubled grinding efficiency and decreased both the grinding force required and wear of the grinding wheel.
As trial applications of mechanical machining for micro parts production, a micro lathe turning system has been constructed. The size of the micro cutting system is so small that the working situation must be observed under an optical microscope. Circular bar of 0.3mm in diameter is cramped and rotated with little eccentricity. Several materials such as copper, brass and Ti are cut into the minimum size of about 10 μ m in diameter. And also the influence that is given to cutting force under several cut conditions has been discussed. Especially, the influence of the depth of cut and the feed of cut on the cutting force and the specific cutting force has been investigated in the cutting process of each material.
The purpose of this study is to make clear the influence of cutting speed on the transition behavior from brittleto ductile mode in the cutting process of single-crystal silicon using a single point diamond tool. The main resultsobtained in this study are summarized as follows : (1) When the feed rate falls below a critical value fc at a constant cutting speed and a constant tool depth of cut, the brittle/ductile mode transition phenomenon takes place. The critical feed rate fc increases with an increase of the cutting speed. (2) The critical depth of cut dc at which the brittle/ductile mode transition phenomenon occurs increases with an increase of the cutting speed and it is hardly affected by the feed rate. (3) Mirror surfaces with roughness of 15-30 nm Ry can be generated by optimizing the feed rate and the cutting speed.
This paper deals with the grinding of the micro aspherical surfaces. A new grinding method and a grinding system with the inclined rotational axis of micro grinding wheel were developed. The grinding wheel axis is 45 degrees inclined from the workpiece rotational axis. The micro wheel was resinoid bonded diamond wheel of #1200 in the grain size. The wheel was formed to a precise columnar shape of 0.8 mm in the diameter by a single crystal diamond truer on the machine. The grinding spindle is equipped with an air bearing and the maximum rotational rate is 10 × 104 rpm. In the grinding test, WC (tungsten carbide) of the glass molding die was tested. The primary grinding workpiece was measured for the distributions of the form deviation profiles to evaluate the deviations of the tool positioning and the tool radius. The NC-program was then edited to compensate reproducible errors. By the developed system, the form accuracy of about 0.1 μ m P-V and the surface roughness of less than 0.03 μ m Rmax were obtained.