The PZT actuator deforms about 10μm for 100 volts of input. When a larger output deformation is needed, the displacement magnification mechanism has to be applied. In this study, two types of FEM analysis model for displacement magnification mechanism with PZT actuator are proposed based on sample models. Unidirectional thermal expansion model is used to express the deformation of PZT actuator. The analytical results showed good agreement with the experimental results in terms of deformation. The properties of displacement magnification mechanism with PZT actuator were investigated analytically.

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A panel subjected to aerodynamic forces is a typical nonconservative structual system of two-dimension. When aerodynamic forces increase over the critical amplitude, the panel experiences the dynamic instability of panel flutter. This study concerned with the structual design improving the stability limit of a panel exposed to supersonic flow by means of adaptive structure with piezoelectric material. Piezoelectric material embeded in the host structure material was connected to resistance-inductance shunt circuit, and expected to work as passive dampers. Maximum critical flow velocity of panel were obtained by the optimization of the allocation and circuit parameter of piezoelectric passive dampers in the context of simple genetic argorithm. Effect of the method for nonconservative panel structure is demonstrated by numerical cases.

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The contact surface of deformable continuum body has importance on surface deformation and traction simultaneously, since the surface deformation due to the contacting object sometimes yields such surface traction that accompanies the severe stress conditions for the deformable body as well as for the contacting object. This study discusses a mechanical problem of deformable continuum body of hyper elasticity with surface traction and deformation prescribed simultaneously. Such a problem is considered as a design optimization problem in the context of homology design concept. The homology index for the prescribed deformation is defined on the body surface with the prescribed traction force, and the structural compliance minimization problem is formulated by epsilon-constraint technique for homology index in the context of the SIMP method for the topology optimization and solved by sequential linearization technique. Numerical case demonstrated the effectiveness of the proposed idea.

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In this paper, we will show the integrated optimization system that is composed by RBF as approximation tool and Genetic Range Genetic Algorithms as optimizer. This system has function of optimizing radius of basis function in optimization, indication of next searching points by using basis function and optimization by using Genetic Range Genetic Algorithms that is a step further of Adaptive Range Genetic Algorithms. All these system is composed in Excel platform, thus, user can used them easily without knowing neither RBF nor GA. In order to show the effectiveness of the proposed system, we will show a numerical example that has multi-peak.

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This paper proposes a mini-max type formulation for strict robust design optimization under correlative variation based on design variation hyper sphere and quadratic polynomial approximation. The proposed method aims that all points within distribution region strictly satisfy constraints and the maximum of objective function is minimized. For this purpose, the objective function and the constraints are approximated as quadratic polynomials over the region and the design space is diagonalized and isoparameterized into a hyper sphere. The maximum of each function is obtained by mathematical means with less computation cost based on these transformations within the inner loop of mini-max type optimization computation. The validity of the proposed formulation is ascertained through its application to a two-dimensional numerical example.

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A new and direct topology optimization method of generation for rib layout pattern so called as growth technique is proposed in this paper. The method suggests that the ribs extend from the ground structure just like branches of tree grow from seed or trunk, so it should obey a certain growing and branching rule like tree. The initial growth points, so called seeds, are specified in advance, and baby ribs around seeds on the ground structure have the ability to grow along the grid nodes of finite elements by taking into account their design sensitivities. The potential ability of branching will be assigned to the ribs greater than the specified threshold dimension. During the growing process of rib, the volume growth rate is controlled so as to be possible to create new branches and to eliminate degenerated ribs. The stop condition of the growth process is that the rib volume reaches the given upper limit value. The validity and effectiveness of the suggested method is confirmed by the numerical results of some typical rib layout design examples, and optimal patterns of rib layouts for square plates under different combinations of loads are demonstrated.

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This paper proposed a simulation algorithm to construct bifurcated network patterns in the specified region in advance, such as tree roots and arterial network. The growth and bifurcation rules are extracted from the observation of natural bifurcated networks, and density distribution and its variation are taken into account. Some simulation results are shown in two- and three- dimensional spaces.

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In recent years, researchers have become increasingly interested in multi-objective optimization (MOO). However, little work has been done to interpret the MOO solutions in multidimensional space. This paper presents an evolutionary clustering approach to interpret the solutions with its visualization. To comprehend the correlation of each solution and each cluster, the MOO solutions were visualized into the principal component space and the real design space. We recommend that the approach outlined in this study would be applicable to the MOO solutions in the space beyond human perception.

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When deciding maintenance policy for plant machinery by reliability theory, the parameters of cost, such as maintenance cost, inspection const and cost of losses due to failure etc., are necessary. However, in many cases, these parameters are difficult to exactly obtained with certain values. In this study a method of fuzzy decision-making is proposed to decide optimum maintenance policy for plant machinery.

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Up to now, many mathematical methods to decide the time interval of maintenance or inspection are established by the reliability theory, but most of them are difficult to be applied to practical plant machinery because these mathematical models for the maintenance policy are too complicated to be solved as a numerical expression of solution and practical plant conditions or field data are not satisfied the required conditions of these mathematical models. In order to overcome the difficulty, the purpose of this paper is to develop a decision-making method of time interval of maintenance and inspection for plant machinery maintenance by genetic algorithms (GA) when plat machines are preserved by time based maintenance (TBM) or condition based maintenance (CBM).

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Risk-based maintenance technique has been applied to several kinds of plants such as fossil power plants and cranes. Risk is defined as a multiplication of likelihood by consequence of a failure with semi-qualitative method. This is based on engineering judgment with inspection data and operating conditions and fatigue damage assessment and so on. When RBM method applied to plants, appropriate damage assessment needs to be selected to get correct results. And the correct inspection technique also needs to be selected.

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We introduce Digital Maintenance Field, which is structured in a computer by projecting maintenance information on real nuclear power plants to virtual space. The objective is to develop intelligent systems technology, which enables to collect the information on plant maintenance flexibly by various sensors and mobile robots, digitize and compile it in a computer, archive and maintain it in a virtual space, and provide whatever contents of the information to anybody whoever wants whenever he wants wherever he wants in whatever forms. For constructing it, collection of plant inspection information by mobile robots is assumed. Life-cycle adaptive maintenance technology is developed for predicting the deterioration of equipment and enabling maintenance planning for mobile robots to inspect the plant. Adaptive robot technology is also developed for enabling mobile robots to move to access to any inspection location. The collected inspection information is feed-backed to the digital maintenance field for its compilation.

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In the near future, maintenance work will include not only checking or repairing work but also disassembling or upgrading work on customer site. Computer supporting is one useful approach to help workers in the extended maintenance work. In this paper, first, changing of maintenance work in accordance with trend to recycle-oriented society is considered. Second, computer recognition of human work process is introduced as an important function in the work support system. Third, problems for constructing the work process recognition system are arranged based on previous studies.

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Maintenance Technology for Best Condition Manufacturing Aimed at Recycling-Oriented Society. Engineering developments have been sought and actions been taken in mass-producing plants in view of realizing a recycling-oriented society. We found an optimum choice for the operators and maintenance engineers to make at point of production. We propose a model on how much environmental cost we can reduce by improving resource - and energy-saving technology.

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This paper proposes a LOC model for decision on replacing or repairing equipment. In case that we have to prepare huge replacing cost, it is very difficult to decide to replace or to repair them. Usually, we inspect them regularly and repair it if damage is found. We are requested to maintain equipment to use them longer, but damages due to being used longer, will induce increasing repairing cost. We should know the best optimum timing that we should replace them from the cost point of view. We built up a LCC model for calculating time when they should be replaced.

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Life Cycle Assessment (LCA), which is to evaluate the environmental load of a product, usually requires the detail data on the life cycle of the product. Since some of the data are secret in a company, it is sometimes difficult or impossible especially for people outside the company to perform the LCA of a product produced by the company. The authors propose a decentralized LCA approach addressing this issue. In this approach, a computer in each company has its own data for inventory analysis, which are hidden from the outside of the company by using distributed object technology. When an operator requests a computer of a company to perform the LCA of a product, this computer first performs the inventory analysis for the company's manufacturing process. Next, this computer requests the computers of other companies such as suppliers or recyclers to perform the inventory analyses for their processes. The tasks mentioned above are fully automated. Using this approach, an operator does not have to examine the detail information on the life cycle of a product.

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For realizing the effective re-use and circulation of parts, we are proposing the concept of "Part Agent" that goes through network along with the corresponding real part of product and handles its information throughout its life cycle. In this paper we discuss the requirements for application of Part Agents such as type of information, number of parts, and frequency of communication. Then the technologies required to realize this system are estimated such as capacity of memory and size of chip attached to a real part, universal connection with network, size and performance of sensors, capacity of network, and network-based agent software. Finally how to combine these technologies to fulfill the requirements is discussed.

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"Reuse" is an important life cycle option for constructing close-loop product life cycles, since it can preserve values of parts and modules. In order to clarify issues of reuse, this paper proposes an indicator "marginal reuse rate, " which is defined as a rate of overlapped area of sales curve and disposal curve against total sales amount of a product. The rate indicates theoretical upper limit of reusability. After formalizing the marginal reuse rate, this paper analyzes some product life cycles using the rate. These analyses clarified that increase of collection rate and extension of sales period are effective for increasing the rate in case of rapid product life cycles, and multi-generation design and life cycle management are effective in long-life product life cycles.

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For enabling unit reuse, which has an advantage of simplifying disassembly operations compared with part reuse, it is necessary to identify residual lives of parts of the unit without disassembling it, if deterioration of parts cannot be simply evaluated from the cumulative operating time of the product. In this study, we propose a diagnostic method for evaluating part deterioration of a paper feed unit of copying machines by means of measurement of paper feed velocity. Diagnostic experiments shows that decrease of the frictional coefficients of pickup roller can be identified by decrease of acceleration of the paper.

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For proper management of life cycle of machines and manufacturing facilities, it is important to perform appropriate reliability design, and to keep machine status for better reuse and recycling opportunity. FMEA(Failure Mode and Effect Analysis) is a powerful method to extensively investigate possible machine failure and functional deterioration, and to predict reliability. However it is very time-consuming and tedious to perform FMEA by conventional manual method. In this paper, computer aided FMEA is proposed, and its theoretical basis is discussed. An extended product model is introduced, where possible machine failure information is added to describe used machine status. By applying generic behaviour simulation to extended product models, it is possible to detect abnormal or mal-behaviour of machines under used conditions. Based on this behaviour analysis and extended product models, FMEA process can be performed by computer-aided manner, and can be very efficient to avoid laborious work and possible errors.

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This paper reports the development of micromotors using Electro-Conjugate Fluids (ECFs). ECF is a kind of dielectric fluids, which produces jet-flow by applying high DV voltage between electrodes inserted in the fluid. By applying this phenomena of ECFs to motor principle, small-sized and lightweight motors can be realized. We call these motors Micro ECF Motors. In this paper, inner diameter φ9mm and inner height 1.9mm multi-layered DP-RE-type Micro ECF Motors are designed and fabricated in order to develop more powerful micro ECF motors. Performances of these motors are investigated and discussed.

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In a pin-to-plate gas discharge system, corona discharge took place over a threshold voltage and a relatively large repulsive force, in the order of 100μN, was induced to the pin electrode due to the ionic wind. The force was almost tangential to the pin electrode even when the pin electrode inclined to the plate electrode. The force was utilized for the driving force of small linear and rotational driving mechanisms on water. The linear mechanism was an inclined pin electrode on a floating plate and the rotational mechanism consisted of two pin electrodes on a floating disk at point-symmetrical positions. Experimental investigation deduced that (1) the driving force was induced over the corona onset voltage, (2) the driving force or torque were maximum when the inclination angle was 45 degrees, and (3) the speed of the mechanisms was increased at high applied voltage and a small air gap.

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This paper describes a method for extracting only waves reflected from cavities from GPR images. A technique involving the evaluation and filtering of the characteristics of reflected waves in the frequency domain has been applied to the cavity-reflected-wave extraction problem. As a result, center frequency and half-width of the cavity-reflected-wave are found to be different from those of buried pipe. And it was determined that this technique is effective in extracting only signal from cavities by setting a band pass filter on the frequency feature such as the center frequency, the half-width, and the direct current component ratio to be appropriate for cavity problem.

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Abstract An optical three-axis tactile sensor is comprised of a silicone-rubber sheet, an acrylic plate, a CCD camera and a light source. A silicone-rubber sheet has an array of 8×9 sensor cells consisting of a columnar feeler and 2-by-2 conical feelers. Since the 2-by-2 conical feelers are detached from the acrylic board under too large horizontal force, the three-axis tactile sensor can detect friction coefficient of the object surface with limited range of horizontal force only. In the present paper, the authors proposed a new design of a sensing element consisting of a columnar and a conical feeler to trace horizontal movement of the conical feeler. To evaluate the new design, we conducted a series of experiments using an x-z stage and a two-axis force sensor. It was found that the relationship between feeler movement and horizontal force depended on applied vertical force and that relationship between vertical force and contact area did not depend on horizontal force. Therefore, since modification is possible according to value of vertical force and conical feeler does not detach from the acrylic board under considerable large horizontal force, the new sensing element can detect horizontal force within wide rang of horizontal force.

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This paper describes the capability of a pin-typed tactile display to present virtual textures. Each pin of the tactile display was driven by a bimorph PZT ceramic actuator; the stroke of the pin was about 1mm. The size of the pin-array was 8-by-8; the pin-array typed tactile display was mounted on a mouse. In order to evaluate virtual textures presenting of the display, virtual textures are expressed by an equation of convolution of two-dimensional sinusoidal waves and human subjects adjust one of parameters included in the equation in the psychophysical experiment. In a preparatory experiment, two human subjects adjusted a y-/x-directional wave number ratio. r. Since Δr/r was within from 0.2 to 0.35 where Δr was difference between adjusted and provided wave number rations, and the value of Δr/r was almost same as normal Waber fraction for tactile sensation, the present mouse could display the virtual texture.

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Adaptive Front-lighting System (AFS) is designed to improve nighttime visibility by optimizing the headlight beam distribution pattern based on existing driving conditions (ex. vehicle speed), driver inputs (ex. steering wheel angle), and road configuration (winding or straight). This paper describes the structure and the public road test of the AFS prototype installed on Mitsubishi ASV. The AFS consists of some sensors, electronic control unit, moving sub-reflectors and auxiliary side bulbs. The headlight beam distribution is controlled by moving the sub-reflectors and the auxiliary side bulbs based on the steering wheel angle and vehicle speed. Brake frequency, flicker frequency and some other evaluation results show the AFS's positive effect in a series of winding road test.

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When seeing a specific figures which is represented by the Kanizsa triangles, we perceives subjective contours that do not exist physically, together with subjective figures, and, furthermore, we perceives overlaps among the figures. To explain such kind of human illusory vision, the authors proposed a multi-stage bottom-up model, and, especially, quantitatively examine a hypothesis selection stage with psychophysical experiments and simulations.

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The image segmentation method based on the multi dimensional co-occurrence matrix belongs to the class of region-based techniques. It uses a feature vector composed of multiple features for multiple windows neighboring a pixel. And a mixture Gaussian distribution is fitted to the feature vector set for pixels. There are two problems on dealing with boundary pixels. As for the first problem, boundary pixels cause an ill effect in the estimation of distribution model. It was solved by the exclusion of boundary pixels. The other problem is in a difficulty when assigning the boundary pixels to the estimated mixture Gaussian distribution model. The later problem was examined in this paper. Each pixel is assigned according to the posteriori occurrence probabilities calculated from the features of each pixel.

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To realize a practical micromachine using fluid power with high power density, a novel microvalve using an MRF (magneto-rheological fluid) drop has been proposed and investigated. MRF is supported as a valve-body by a permanent magnet and is deformed by an electromagnet to control the opening. The proposed microvalve solves leakage problem caused by the large machining errors compared with its small size. To expand the pressure control range, in this paper, the magnetic poles are fabricated with different shapes and the optimal shape is selected based on the displacement of MRF valve-body due to the applied current. Then, the flow control characteristics are experimentally investigated with tap water as a working fluid.

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In this paper, to obtain further performance of the resonantly-driven piezoelectric micropump developed as a micro fluid power source applicable to microfactory or micromachines using fluid power, a novel check valve that actively controls valve open/close motion using piezoelectric actuator is proposed and static characteristics between flow rates across the developed check valve and applied pressures are investigated. Employing the active-type check valve instead of conventional passive-type is expected to realize some advantages such as an increased valve-opening area and response, a low damping ratio and a bi-directional flow using an adequate timing control for closing motion. A prototype micropump using two active-type check valves for inlet and outlet is fabricated with the effective size of 17×18×11(mm)^3. Through experiments on frequency characteristics of flow rate without load pressure, the validity of the proposed active-type check valves is verified.

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The research finds that it is wrong that the increase of the frequency results in the decrease of the amplitude of piezo vibrator is the main cause for the phenomena that at the time of increasing the frequency but decrease the flow output. And the experiment has testified that the existing theory is incorrect; then put forward that valve lag is the main cause for the phenomena that at the time of increasing the frequency, and decrease the flow capacity. Finally, a new type valve-the shape of "E" is introduced accord with the theory of the valve lag.

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This paper describes an active control system for reducing transmitted noise, which is caused by floor impulse and perceived at the downstairs room. The active control system actuated by bi-morph piezoelectric elements are installed in the intermediate space between the upstairs floor and the downstairs ceiling. The bi-morph piezoelectric elements are reinforced for improving bending strength by polyethylene plate with low bending stiffness. H-infinity robust feedback control system is designed assuming application of four actuators and four sensors to eliminate the sensor signal. The control system design is based on system identification results by using subspace method. Some control experiments are conducted to prove the effectiveness of the control system.

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A calculation system is urgently required to develop which predict the noise of fan structure attached in motor-shaft. This paper describes two main contents of predict the dynamic motion of the fan structure. One is the fan structure modeled by FEM. The vibration modes agreed well with measured and FE-model-calculated. The other is that the vibration response of fan structure was calculated using torque pulsation and FE-model. The torque pulsation of the motor acts on the fan structure, and the fan structure vibrates in the circumferential direction. This torque pulsation can be calculated by using a two-phase equivalent electric circuit. The calculated vibration response values agreed well with experimentally measured ones.

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The dynamic behavior of a damped vibration system containing thixotropic materials is experimentally investigated. Thixotropic materials are substance which liquefy when stirred or shaken and return to the hardened state upon standing. We construct a device to evaluate vibration of a washing machine containing thixotropic materials and vibration tests are performed using the device with a rotating unbalance turning in inner tub. Normally, the outer tub of a washing machine is suspended by the supporting bars with damping mechanism. We proposed the new damping mechanism with thixotropic materials. Transmitted force from outer tub to outer housing is measured. The tests indicated that optimum shape (thickness and diameter) of piston changes when the consistency of thixotropic material changes.

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The force-feedback from the slave robot to the master robot is effective in a master-slave system. However, when the slave robot is not contact with its surroundings, we can't adopt the conventional force-feedback master-slave system, because there is no force acting on the slave robot. Thus, a method using a virtual force-feedback was suggested. Though the virtual force was calculated by an impedance model, it included some oscillation, and this might raise a system unbalance. In this study, the authors improved the design method of the virtual force-feedback master-slave system and introduced the disturbance observer from the viewpoint of the system stability and maneuverability.

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This study describes obstacle avoidance with rotary motion of long loads for overhead crane. We proposed path and posture planning method that was constructed by interference check and potential method. In order to accurately track to the reference trajectory, LQ preview servo system was adopted. Simulation results showed the effect of preview feedfoward compensation.

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A crane mounted on a tower-like flexible structure called the 'Tower crane' has a problem that a fast transfer of the load causes the sway of the load and the vibration of the flexible structure. Furthermore if the length of the load rope varies, it is difficult to control by the fixed compensator, because the natural frequency of the load rope and gain of the plant to control input vary also. This paper discusses the control design considering operator command with varying load-rope length. A two degree-of-freedom control system is designed, which is consists of the feedforward controller by using a command-shape filter and the gain-scheduled controller considering varying load-rope length. From the results of the experiment, it is shown that the work efficiency is increased by using our proposed control system.

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Flexible suspension system like bogie mechanism type suspension is used for running equipment of crawler-type construction machine especially to improve the comfortability in riding. However, in the running equipment with bogie mechanism, there are many unclear points in the dynamic behavior and loads due to the complicacy. This paper shows the dynamic behavior of crawler-type construction machine with a bogie mechanism when it travels over a bump by using a simulation method. The fundamental method has been established in the first report of this study. The time histories of the acceleration at the operating seat position and the suspension forces are calculated. The simulation results are compared with experimental results and the validity of the simulation method is verified.

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In a processing facility, the plate usually travels at a velocity of more than 10m/s. When a long steel plate travels at high speed, rollers are usually used as supporters. However, when rollers are used, deterioration caused by cracks in the process of coating or gilding is possible. We have proposed noncontact guide by using electromagnetic attractive force for a traveling steel belt. In this study, permanent magnets were installed in the place where the electromagnet was not set up in order to suppress the elastic vibration. To verify the usefulness of the proposed system, a control experiment was performed.

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In coping with the trend toward the much higher powered electric-motor driven injection molding machine, multi-AC servomotors control system has become necessary in order to control the molding machine mechanism. Thus, it is inevitable to use the synchronous position control technology not to cause the excessive mechanical stress in the machine body. Accordingly, it is much necessary to have a load simulator of the molding machine to study the control technology. This paper clarifies the similarity law between the actual molding machine and the simulator so that we are able to anticipathe the control performance at the actual machine from that at the simulator.

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In coping with the trend toward the much higher powered electric-motor driven injection molding machine, multi-AC servomotors control system has become necessary in order to control the molding machine mechanism. Thus, it is inevitable to use the synchronous position control technology not to cause the excessive mechanical stress in the machine body. Accordingly, it is much necessary to have a load simulator of the molding machine to study the control technology. This paper clarifies the design method of the simulator based on the similarity law at the injection molding control so that we are able to anticipathe the control performance at the actual machine from that at the simulator.

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These is a problem of which the elastic vibration of a thin steel plate is excited by the nonlinearity of the electromagnetic force and the disturbance to the control signal. In this study, we used the sliding mode control method in which the application was easy for the nonlinear magnetic levitation model. The modeling of the sheet steel was based on the equation of the plate considering the elastic vibration mode. The superiority of the sliding mode control application was examined experimentally on the robustness for disturbance to the control signal and the parameter variation.

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We have proposed a magnetic levitation control system for the sheet steel and confirmed the realization by the digital control experiment. However, the case in which only the levitation control is applied for the steel plate, it has no horizontal restraining force in the traveling. Then, the electromagnetic actuators are installed in order to control the horizontal position of the levitated sheet steel. The electromagnetic attractive control forces of the actuators are given for the faced two edges of the levitated sheet steel from horizontal direction. In this paper, the suppression effect of elastic vibration of the levitated sheet steel in the horizontal noncontact positioning was reported. The results of experiment showed that the elastic vibration of the sheet steel could be sufficiently suppressed and effective could be confirmed to the stabilization of magnetic levitation when the steel plate was transported.

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