143 research outputs found

    An optimal finite-dimensional modeling in heat conduction and diffusion equations with partially known eigenstructure

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    An optimal finite-dimensional modeling technique is presented for a standard class of distributed parameter systems for heat and diffusion equations. A finite-dimensional nominal model with minimum error bounds in frequency domain is established for spectral systems with partially known eigenvalues and eigenfunctions. The result is derived from a completely characterized geometric figure upon complex plane, of all the frequency responses of the systems that have (i) a finite number of given time constants T/sub i/'s and modal coefficients k/sub i/'s, (ii) an upper bound /spl rho/ to the infinite sum of the absolute values of all the modal coefficients k/sub i/'s, (iii) an upper bound T to the unknown T/sub i/'s, and (iv) a given dc gain G(0). Discussions are made on how each parameter mentioned above makes contribution to bounding error or uncertainty, and we stress that steady state analysis for dc input is used effectively in reduced order modeling and bounding errors. The feasibility of the presented scheme is demonstrated by a simple example of heat conduction in ideal copper rod. </p

    Application of Dead Beat Control method to the Water Level Control of Small-scale Hydroelectric Power Plant

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    Small Scale Hydroelectric Power Generation is made using the water drop caused by the gradient difference between that of the river and that of the penstock. The water flow in this system apt to vary with time. Especially, at the time of the flood or that of the dry, the flow in the water stream varies largely. To realize the stable generation, it is necessary to maintain the water level in the head tank located in the mid way in the stream channel at a constant level. In this paper, variation of water level is forecasted using two-tank model for the penstock and the head tank and the water level control algorithm is proposed by deadbeat control. The effectiveness of the algorithm is evaluated beforehand using the simulation program of the water environment for the hydroelectric generation system

    Design Support of Transportation Routing for a Multi Layered Factory

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    Recently, it becomes important to improve transportation capability to attain high productivity in manufacturing. One of the necessary schemes to attain the purpose is that the floor layout is initially to be optimized. After the floor layout is determined, reasonable equipment position for transportation is decided. Then the design of the transportation route is to be determined. In this paper, design support system for transportation routing, based on agent method is proposed. To optimize the transportation route, the working space by the side of the equipment is to be prepared. Starting from given floor layout of a three layered factory, an appropriate transportation route is pursuit using Ant algorithm. To check the applicability of the proposed method, case studies are carried out under various constraints and objective functions, and its effects were verified

    Optimal Digital Control Systems Design for Handling Machines using dsPIC

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    This paper presents a method of the controller design for the handling machine by using dsPIC(Digital Signal Processor + Peripheral Interface Controller). Recently, many manufacturing robots are operated in manufacturing facilities, with the aim of labor, cost saving, and improvement of the productivity. Such robots need to have positioning performance of high precision and simultaneously to save cost. In this paper, a digital optimal servo controller is designed, and it is implemented into our barebones controller which involves dsPIC. We have designed and manufactured the controller which is added suitable peripherals to improve the consistency between the mechanical machine operating in continuous time and controller in discrete time. The significance of this research is that digital implementation of the embedded system which has performance-limitation has ensured a comparable result, against the one with PC which has broad utility. When it is used as a controller, it is possible to restrain product prices greatly equivalent PC precision. We demonstrate potential that good control can be achieved even with low cost. Our research has lead to the viability of lower cost and higher performance system for the production process at factories

    Route Tracking Control of Tractor-Trailer Vehicles based on Fuzzy Controller

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    Recently, Factory Automation is actively been carried out in industry. Usually, a single AGV is used to transport products for factory automation. While, a Tractor-Trailer Vehicle can load much more products compared with a single AGV. Addition to this, transportation time can be shortened by separating containers. But, it is not so easy to drive the trailer according to the orbit during running of the Tractor-Trailer Vehicle. In this study, fuzzy control scheme is studied to support satisfactory route tracing of a tractor-trailer vehicle. To extruct the control rules, a fuzzy control system is developed

    Optimization of Inventories for Multiple Companies by Fuzzy Control Method

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    In this research, Fuzzy control theory is applied to the inventory control of the supply chain between multiple companies. The proposed control method deals with the amount of inventories expressing supply chain between multiple companies. Referring past demand and tardiness, inventory amounts of raw materials are determined by Fuzzy inference. The method that an appropriate inventory control becomes possible optimizing fuzzy control gain by using SA method for Fuzzy control. The variation of uncertain demand is given to the proposal method. Furthermore, the method of forecasting demand and the effectiveness of fuzzy control method are confirmed by numerical experiments. As the results, the proposal method suppressed increase in an unnecessary cost when demand varies

    Human Support Agent for Design and Diagnosis using Classifier System

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    As is well known, an advanced knowledge and know-how are needed in the design and the diagnosis work. Further, human experts can cope with the recent trend of customers needs. Therefore, the design and the diagnosis work have been privately performed in the past, and its information cannot be shared. In addition, the number of experts is decreasing. It is a very important problem to maintain and to extend experts technologies having been built up. For the purpose, methods and systems for technical inheritance of the advanced techniques of the skilled engineers are needed to train the unskilled operators and also can assist skilled operators. In this research, attention is focused on the design of analog filter circuit. To attain the target, the circuit structural classifier system to support design work is developed. Furthermore, simulation technology for hot strip rolling mills based on distributed agents is presented aimed to develop tools for the diagnosis of hot strip rolling mills operation

    Surface Defect Inspection of a Cutting Tool by Image Processing with Neural Networks

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    In this research, an image processing method and a system for inspection support of a rod figured cutting tool are developed. As is well known, the visual inspection of a cutting tool by image processing is not easy, because cutting blade have a helical blade structure. To cope with the problem, an experimental facility with rotation and longitudinal tool shift functions to enable acquisition of blade surface pictures along a cutting rod is developed. The type of the defect treated in this paper is the spot of coating on blade surface. To judge the quality of the processed image of blade surface, neural network with autonomous learning is used. The processed image of cutting tool is divided into 64 × 64 blocks used for the input to the neural networks. Before input, each block data is preprocessed applying a edge detection filter and a transformation by the discrete fourier transform (DFT). Using these technologies, the experimental inspection system is built and tested to check the capabilities of the inspection algorithms. The diagnostic performance of the surface defect of a cutting tool was confirmed. There remained a problem to mis judge the normal tools as the defect

    Cooperation of Production, Product Handling and TransferScheduling for Semiconductor Fabrication

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    Various kind of productions are made in semiconductor fabrications, where it employs the production system with multiprocesses and multiple Automated Guided Vehicles(AGVs) for transportation. It is difficult to optimize planning of production and transportation simultaneously because of the complicated flow of semifinished products. This paper describes the formulations of production scheduling, transportation routing and sequence planning of material handling system, and algorithm for simultaneous optimization of plannings by using solution space reduction and simulated annealing method. In this paper, all production system is decomposed to the production scheduling problem, transportation routing problem by AGVs and sequence planning of material handling system with managing stockers and buffers. Production scheduling problem and transportation routing problem are solved by the optimization algorithm using the decomposition routing problem. Sequence planning of material handling robot problem is solved by the algorithm using simulated annealing method
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