Recently, transportation systems such as distribution centers have become large and complex. Therefore, it is considerably important to evaluate efficiencies of transportation of luggage and find the optimal transporting schedule or the layout of each system. In order to solve this problem, various methods have been developed. Simulation is one of the most valuable methods for evaluating whether a layout and a schedule are acceptable or not. However, designers have to analyze the results of the simulation by themselves. A new Time-Skipping method for evaluating efficiencies automatically has been presented in the previous paper for resolving this problem. A method for modifying a distribution schedule automatically is presented. This method consists of the following three subprocedures. (1) Evaluate whether each transportation path is congested or not, by using Time-Skipping method. (2) Find the most congested path, reduce the number of luggage passing through the most congested path and evaluate again. (3) Iterate procedures (1) and (2) until the optimal schedule is obtained. Three types of systems for transporting luggage have been tested. The results show. that this method can be used for evaluating distribution systems and modifying a schedule.

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This paper describes the reconstruction of the old CAE system which has already been constructed to design an optimal highintensity ultrasonic system. As the old CAE system employs the optimizing program based on the simultaneous search plan, the system takes a long time to search the optimal solution of the complex ultrasonic system with many design parameters. In this paper, the search algorithm which can search the optimal solution of the complex system in a short time is proposed, and the algorithm is named the improved local search method (ILSM) after the local search method. In addition, the new CAE system is reconstructed by the use of the optimizing program based on the ILSM. Then, the two-dimensional and three-dimensional designs of a solid hom that is one in several components of the high-intensity ultrasonic system are presented for the examples of applications of the new CAE system. As a result, it is confirmed that the concept and the formulation of the ILSM are quite right, and that the new CAE system can efficiently search the globally optimal solution.

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This research proposes a surface generation method which satisfies the designer's intention to the surfaces and smoothness of the reflected images on them. The method directly determines the curvature distribution of a surface, which is represented by a locus of the evolute of the generatrix moved along the directrices. In this report, the evolute surface formed by the locus is modified according to a criterion of the hilight lines which are silhouette pattern of the given surface. The criterion is the square of projected curvature of highlight lines per unit length. To obtain the surafaces which satisfy the criterion, the evolutes of their sections along the direction of highlight lines are determined to change smoothly. They are represented with two segments of the second-degree rational Bézier curves, whose parameters are determined to minimize the criterion. The method is extended to determine a surface when a highlight line is given by a designer. Some examples of boundary curves with various patterns of curvature variation are shown to be generated as smooth surfaces.

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The introduction of FMS (Flexible Manufacturing System) in machining of large-size pistons (greater than outer diameter 170 mm) has been desired, because various shapes are demanded and moreover the production lot size is small. The automation in FMS construction is essential, but in large-size pistons this is very difficult because the following problems have to be overcome: (1) The integration of various operations for effective floor space utilization. (2) The robot loader with the ability of accurate positioning as well as heavy movable load carrying capacity is demanded, because the positioning accuracy is necessary to the same degree of small (or middle)-size piston. (3) Measurement after every operation is essential to prevent the production of defective pistons, because the unit cost of the large-size piston is very high. (4) The dimension of the outer diameter in the machining of large-size pistons should be automatically controlled, but it has been dependent on the worker's skill owing to the complicated shape and its variety. The FMS construction for large-size piston machining was completed by applying the following representative techniques: (1) Integrated system of multiple operations for effective floor space utilization. (2) Automatic conveyor system consisting of robust robot loaders with accurate positioning and AGV (Automated Guided Vehicle). (3) Inner cooling pipe sensing by the ultrasonic inspection instrument and measuring system. (4) Development of non-circular outer diameter finishing machine being capable of machining complicated profiles and any type of piston. The advantage of constructed FMS is that the productivity increases to about 3 times as compared to the conventional manual line.

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This paper surveys end-of-life strategies currently used in the electronics and appliances industries and identifies product characteristics that guide designers to specify appropriate strategies. The survey indicates that important characteristics are wear-out life, design cycle, technology cycle, functional complexity, number of materials, and number of parts. Two key characteristics, wear-out life and technology cycle, serve as factors to categorize products' appropriate life-cycle scenarios. The categorization leads to a methodology that guides product designers to seek environmentally friendly designs, and to identify opportunities for developing new recycling technologies. Further, an application of quality function deployment (QFD) as a design support tool for helping design engineers early in the product design based on appropriate life-cycle strategies is proposed.

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Determination of tolerances is very important during product manufacturing in order to maintain low cost while achieving a consistent level of product performance. The purpose of this study was the improvement of productivity of optical products like as SLR lens. Therefor this study had proposed the "Virtual PT System" concept as a method to realize the suitable tolerancing for optical products and realized this system. According to this concept, this report proposes the new product model of SLR lens to evaluate the optical performance in real product condition. The proposed SLR lens model can represent uniquely the position and orientation of all parts as relationship of coordinate transformation. And also, this model can represent the mechanical structure with both manufacturing error and assembling error by same manner. Using this SLR lens model, the designer can easily obtain the both lens surfaces decentering amount and optical performance on real product condition precisely.

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A series of papers presents a new calibration method particularly for up to a middle size CMM. The method is able to provide the 21 parametric errors only by performing the coordinate comparison. An automated calibration system for the production stage of CMMs is realized. Following to the first report describing the adopted linear parameter model and simulation result under the ideal situation, contribution of variance in the observation to the result is considered in this report. Application of the error propagation analysis through the linear model is proposed. Estimated parametric error components are evaluated by the propagated variance on the linear guide way model with six kinematic freedoms. The result in seven different stages in variance shows that six parametric errors are possible to be estimated simultaneously with in the propagated reliability range.

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Attentions are widely paid to the application of parallel mechanism for its lightness, high rigidity, high speed and high precision. Additionally, the inverse kinematics is also easy to be analyzed. It is important to clarify the volume and shape of the working space to avoid completely the self-interference and singular point occurred among the elements. This research work, taking HexaM machine developed by Toyoda Machine Works as the model, is to make clear the relationship between the working space and the position of the links. By detecting the interference and the singular point, mathematical formula and computer software to analysis the working space of the tool are developed. The results of simulation and experiment show that the developed software is appropriate and the proposed formula is practical to express the relationship between the working space and the position of the links.

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Parallel manipulators have many useful characteristics, that is high speed motion as the inertia is light, rigid structure and full 6 degrees of freedom. There are many different type parallel manipulators. Stewart platform. is the most typical type which has 6 linear actuators called struts, A new type parallel manipulator named PSSP has been proposed, which is moved with three pentagon type SCARA robots. Parallel manipulators have many singular points in the working space, on the points the stiffness of the structure becomes zero. It is very important to study the location of singular points and characteristics. The standard approach of the study on singular points is to find the zero points of jacobian matrix determinant. In this study a new approach to analyze the singular configuration of parallel mechanism to resolve the eigenvalue and eigenvectors of stiffness matrix. PSSP robot is analyzed by the method.

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Basic research for developing a small hovering robot is performed. Small hovering robots will be very effective for inspecting and observing the site and circumstances in a narrow or dangerous space, where human cannot access safely. In this paper, how to hover the small robot successfully in air, especially by using rotating blades mechanisms is investigated, and it is clarified that measured lift force characteristics almost agree with the theory, and main parameters governing the lift force are the wing length and the rotation speed. Using a 135 mm diameter rotor, lift of 0.3-0.4 N can be obtained. The wing size should not be reduced so much because the wing length has drastic influence on the lift. For this reason, methods to reduce the robot size without reducing the wing length are investigated When putting a part of the rotor upon another one, the lift is weakened only less than 10%, and minimizing the robot size is possible. In order to verify the present technology level, a four-rotor hovering robot with a size of 238 mm square and a mass of 121 g is manufactured, and basic performance is exhibited

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Although trimmed surface patches are useful to represent complex curved objects such as a die, and are supported by most current CAD systems, it is difficult to make tool paths rapidly and stably based on the trimmed surface patches. The reason is that a trimmed surface patch is defined generally on a parametric domain trimmed by free-form curves and it is difficult to recognize available portions of trimmed surfaces. In the previous report, a method for tool path generation with surface subdivision using bounding spheres was proposed, by which tool paths could be made based on a surface model rapidly and stably. In this paper, the previously proposed method is extended to process trimmed surface patches. Thus, it is shown that tool paths can be generated for trimmed surface patches keeping advantages of the previous method.

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This paper proposes a step climbing mechanism for the "screw principle microrobot" to climb and pass automatically a step existing between pipes with different diameters without any special actuators nor motion control. For the purpose, the relation among the height of step, tire size, and driving torque is first theoretically analyzed and is experimentally examined. Based on the diagrams drawn using the obtained relations a step climbing mechanism to climb and pass both of concentric and eccentric steps between two pipes of 100mm and 75mm diameters is designed. A "screw principle microrobot" is then assembled by connecting the two step climbing mechanisms with a connecting coil spring. It can pass the steps automatically and smoothly, also the running performance is experimentally examined using some pipes which have a step at different positions.

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In this paper, a novel touch trigger probe which has a totally different construction concept, namely, a pneumatic ball probe has been developed. This touch trigger type pneumatic ball probe consists of a small probe ball, a thin pipe, a pneumatic trigger sensor and a vacuum pump. The fundamental concepts and theoretical analysis of the pneumatic ball probe are described. A prototype of the probe is made and tested. From the experimental tests, the measuring force is reduced to a great extent by using this structure of separating the probe ball from the stylus. The fundamental analysis and the experiment show that it is possible to measure the distance between two walls such as a groove or a drilled hole without restriction of material for two dimension measurement. Using this pneumatic ball probe, it is found that the width between gauge blocks could be measured within a standard deviation of 1.1 μm as well as it is influenced by the vacuum of probe and the inclination of the measurement.

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Hard and brittle materials have two modes of material removal, ductile and brittle. There is a ductile-to-brittle transition between two modes. However, the mechanism of ductile-to-brittle transition has not been clarified sufficiently. In this study, using a microscratching tester which can detect crack initiation by acoustic emission (AE) sensor, the scratching tests of single crystal silicon are carried out to investigate the effects of crystallographic orientation, doping and workpiece temperature on the ductile-to-brittle transition. The critical force Fc is defined as the cutting force when AE occurs in the scratching test. It is clarified that Fc is affected by the parameters of crystallographic orientation, doping and workpiece temperature. It is considered that the mechanism of ductile-to-brittle transition in the single crystal silicon is closely related to the condition when dislocation occurs.

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This paper describes the numerical simulation of the orbital debris impacts on machined ultra precision surface under space environmental condition. The simulation deals with the degradation process of copper mirror surface by the impact of a diamond debris, where the impact speed is 6 km/s and diameter of debris is 10.4 nm. Influence of mirror surface profile on the degradation mechanism and the surface roughness is evaluated as well. From several molecular dynamics simulations, various degradations formed on the ultra precision surface due to the impact of space debris can be inferred, such as generation process of craters, sizes of craters, stress distribution and temperature of the specimen. It is clarified that the impact of debris makes worse the quality of the mirror surface at least nanometer level even by an impact of space debris in the size of several nanometer.

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To develop nondestructive estimation technique for surface electronic structures of ultraprecisely prepared surfaces is very important and strongly required. SPV (Surface Photo-voltage) effect which can be observed non-destructively has been focused as an interesting phenomenon having possibilities to be sensitive to the properties of the processed surfaces. In this work, new detection system of surface photo-voltage signal with extremely high sensitivity has been developed. Si surfaces finely-prepared by ultraprecision machining processes are observed. As the results, sufficiently high sensitivities are established and some new facts are obtained such as differences of surface state densities between chemical etched surfaces employing different etchants. And the electronic state density in the midgap state of the EEM surface is the smallest in those of observed surfaces in this work and its distribution is shifting to the shallow side of the forbidden band.

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In this paper, structural changes of aluminum crystal by the shock phenomena induced by irradiating the fourth harmonics of Nd: YAG laser were analyzed applying the modified molecular dynamics (MD). In the modified MD method, which has been developed previously by Ohmura and Fukumoto, the MD calculation for metal is carried out compensating the heat conduction by free electrons at each time step. Main conclusions are summarized as follows: (1) Shock wave is generated in the material due to laser irradiation and then travels to the interior. Its propagation velocity is equal to the velocity of longitudinal wave of the material. (2) Dislocations are generated at solid-liquid interface and in solid phase by the shock wave. They move in the direction of depth at first with the shock wave and then move at the velocity that does not exceed the propagation velocity of transverse wave of the material. (3) Strain energy of the shock wave is consumed to generate dislocations and drive them, and decreases gradually. Therefore, no dislocation is generated by too small strain energy. (4) Stress state of the vicinity of an isolated dislocation that is calculated by the modified MD gave good agreement with the results of the continuum theory.

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In this paper, using audible sound caused by the vibration of the work and weight, monitoring methods during the lapping process are discussed. And with a microphone, a non-contact process monitoring method is established. The authors had already confirmed that it is possible to predict the roughness of the processed surface by detecting the vibration acceleration signals of the revolving work. Considering that experienced workers can judge processing conditions by their sense of hearing, it is possible to monitor the process by audible sound.But the necessary useful signals cannot be obtained by just putting a microphone close to the work. So for the purpose of picking up the signal easily, two methods are proposed. They are (1) making the weight into exponential horn shape to amplify the vibration, and (2) drilling holes in the weight and making use of the resonance of the air in the holes. According to the results of the experiment, it is confirmed that if the resonance frequencies of the horn and the air column in the holes are appropriately selected, process surface condition can be monitored by either methods mentioned above.

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