This paper describes a new approach for rapidly and accurately detecting rotation center positions of rotated images and correcting the images.Rotation center position detection and correction of rotated images are important in fields such as LSI and micro-machine productions.In the proposed approach,rotation center position detection and correction of the rotated images can be performed simply and precisely without any repetitive procedure.In the experiments,reference images were synthetically rotated by 0.2∼4.0 degrees with the step of 0.2 degrees to generate input images rotated around many coordinates widely distributed from the center to the boundary in the reference images.The detection accuracy of the rotation centers tends to depend on the true rotation center position and the average of absolute errors of the rotation center detections for all rotation centers is 2.40 pixels.To estimate the correction accuracy,rotation angles and position displacements between the corrected images and the reference images were detected.The correction accuracy for image rotation is about 0.0129 degrees on average and that for the displacement is about 0.052 pixels on average.From the results,it is clear that the proposed approach makes it possible to accurately detect the rotation center position and also to precisely correct the image rotated around an arbitrary position.

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The linear actuator driven by a ball screw mechanism is widely used in the machine tools, since it can raise the machine speed higher. For the purpose of the stability in continuous path control of this type mechanism, it is important to identify the machine parameters, such as inertia, spring stiffness and dominant nonlinear friction. This paper presents a practical method for identifying the nonlinear parameters of the table driven by a ball screw mechanism. In the proposed method, the mechanical system is modeled as two-inertia system. Then, the two-inertia system is represented as an inverse model and the inertia and Coulomb friction of the table and the spring stiffness are identified by using the steepest descent method with a dead band. From the results of the computer simulation, the identified mechanical parameters quickly approach to the true mechanical parameters without measuring the velocity of the table.

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In this paper, we propose a fast and stable human detection based on “Subtraction Stereo” which can measure distance information of foreground regions. Scanning an input image by detection windows is controlled about their window sizes and number using the distance information obtained from subtraction stereo. This control can skip a large number of detection windows and leads to reduce the computational time and false detection for fast and stable human detection. Additionally, we construct a human detection method with little incorrect detection using multiple detectors. The effectiveness of our method is verified by experiments.

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This paper presents a defect detection method based on two dimensional Fourier transform. In automatic visual inspection in factories, the displacement between two inspected images contains both parallel shift and rotation, which causes the inspection process to be highly time-consuming. In the proposed method, the subtraction between Fourier transform magnitudes of two input images is calculated for detecting differences between the corresponding pixels. Due to the shift- invariant nature of magnitudes in Fourier transform spectrum, the method does not require an image registration process for parallel shift. For images rotated by a small angle, a correlation based on one dimensional Fourier transform is calculated to estimate the angle.
Detection experiments are executed on Mac Pro 2.66GHz using images with 256 × 256 to 4000 × 2672 pixels. For the largest resolution images, the method detects differences in 2.39 seconds. The experimental results show that the proposed method has sufficient detection precision and faster computation speed than existing visual inspection methods. Estimation of specular reflection on PCB surfaces and further acceleration of the calculation are to be implemented.

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This research paper introduces a development of production management method for equipment maintenance scheduling and work-in-process (WIP) dispatching or scheduling in re-entrant flow manufacturing systems. The method utilizes and combines two published technologies: discrete event-driven simulation and critical ratio dispatching rule. The research established a method of what-if analysis based on actual WIP configuration. Impact of equipment maintenance on system performance is quantified by the simulation. Then, modified critical ratio parameters is applied to maximize bottleneck equipment utilization. The established method, Dynamic Critical Ratio (DCR), has been implemented to a semiconductor manufacturing system. The implementation has avoided WIP blocking in equipment maintenance and WIP starvation at a bottleneck equipment downstream. As a results, the improvement of bottleneck utilization and total system throughput was observed. In closing, possibility for applying the developed method to other production management activities such as equipment re-configuration for product mix and demand change, work shift management and supply chain planning is discussed.

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Recently, many types of robotic bending system have been introduced in sheet metal industry, and a dual-arm robotic system is one of the most expected systems for flexible bending system. In this study, a planning of regrasp motion of a sheet metal is proposed. The regrasp motion is the most characteristic advantage of a dual-arm robotic system. Since, the path of regrasp motion is decided in free space with less geometric restriction, a graph searching approach is applied in order to find the shortest way between start and goal nodes. The graph is constructed whose nodes are consisted of the configuration of a sheet metal, the grasping position on the sheet metal and posture of the arms. The shortest path is obtained by Dijkstra's method and the motion of arms is decided based on the path obtained. The proposed method is coded in a computer program and effectiveness of the method is evaluated by computer simulation with many sheet metal examples.

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The effect of improving machinability of Ca-deoxidized steels in carbide tool machining operation is widely known. It has been proposed that oxide inclusions in steels,which works as “belag” on the tool surface during machining operation,has been responsible for this effect. In this paper,we have investigated the influence of carbides tool material on belag formation of Ca-deoxidized steel. Oxide inclusions in Ca-deoxidized steel were similar to the chemical composition of gehlenite,which has a lower melting point than oxide inclusions in Al-killed steels,namely corundum. In the P-type carbide tool including (Ti,W)C component,the surface of the worn rake face was uneven because of the difference in wear rates between WC and (Ti,W)C carbide particles in this tool. On the other hand,in the K-type carbide tool without (Ti,W)C component,the worn surface was flat and the oxide layer was not observed on the worn rake face. It was confirmed that the belag was formed by oxide inclusions of gehlenite component piled on the uneven surface during cutting process.

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Novel wafer-cooling system based on direct expansion phenomenon of coolant has been developed in order to improve etching performance for high-aspect-ratio contact (HARC) process. This system provides effective cooling capability and rapid wafer temperature control. In this study, prototyping of basic equipment was performed and etching performance in HARC process was evaluated. As a result, temperature control speed of 0.6 °C/s was achieved over a 300mm-φ wafer. Furthermore, etching rate and mask selectivity at 100nm-φ, aspect-ratio of 20 HARC sample could be increased by around 6% and 14% respectively without any etching profile deformation by 2-step wafer temperature control from 61°C to 50°C during etching in C₄F₆/Ar/O₂ plasma. It is concluded from the results that this system can improve etching performance for HARC.

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