• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.149-155
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• 2012

This paper presents mobile robot control architecture of hierarchical behaviors, inspired by biological life. The system is reactive, highly parallel, and does not rely on representation of the environment. The behaviors of the system are designed hierarchically from the bottom-up with priority given to primitive behaviors to ensure the survivability of the robot and provide robustness to failures in higher-level behaviors. Fuzzy logic is used to perform command fusion on each behavior's output. Simulations of the proposed methodology are shown and discussed. The simulation results indicate that complex tasks can be performed by a combination of a few simple behaviors and a set of fuzzy inference rules.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1683-1684
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• 2008

In this paper, a hierarchical nonsingular terminal sliding mode controller (TSMC) for overhead crane system using nonsingular terminal sliding surface (NTSS) is proposed, which can drive the error to zero in a finite time. Here, singular problem of controller is solved by NTSS. In addition, the controller has the double layer structure because the system is divided into two hierarchical subsystems. In the first layer, the nonsingular terminal sliding surfaces are hierarchically designed for each subsystem, and in the second layer, the whole sliding surface is designed as the linear combination of nonsingular terminal sliding surfaces. The asymptotic stability of the system is verified by Lyapunov analysis. Finally, we carry out simulations on the overhead crane system to illustrate the effectiveness of the proposed control method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.4
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• pp.314-320
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• 2006

Navigation in environments that are densely cluttered with obstacles is still a challenge for Autonomous Ground Vehicles (AGVs), especially when the configuration of obstacles is not known a priori. Reactive local navigation schemes that tightly couple the robot actions to the sensor information have proved to be effective in these environments, and because of the environmental uncertainties, STSF(Space and Time Sensor Fusion)-based fuzzy behavior systems have been proposed. Realization of autonomous behavior in mobile robots, using STSF control based on spatial data fusion, requires formulation of rules which are collectively responsible for necessary levels of intelligence. This collection of rules can be conveniently decomposed and efficiently implemented as a hierarchy of fuzzy-behaviors. This paper describes how this can be done using a behavior-based architecture. The approach is motivated by ethological models which suggest hierarchical organizations of behavior. Experimental results show that the proposed method can smoothly and effectively guide a robot through cluttered environments such as dense forests.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.4
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• pp.619-631
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• 1996

This paper describes an approach for the incorporation of maintenance times into a hierarchical scheduling for a failure prone flexible manufacturing system. The maintenance should not be performed too often because of the resulting reduction of capacity. Most manufacturing systems are large and complex. It is natural to divide the control into a hierarchy consisting of a number of different levels. Each level is characterized by the length of the planning horizon and the kind of data required for the decision making process. The goal of the analysis reported here is to calculate the production requirements while the machines fail and are repaired at random times. The machine failure and preventive maintenance are considered simultaneously.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.2
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• pp.192-203
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• 1999

This paper deals with the order release problem for minimizing weighted earliness and tardiness as well as Work In Process (WIP) in dynamic job shop environments. A newly designed hierarchical order release mechanism is developed for efficient real-time control of the earliness/tardiness and WIP. The hierarchical order release mechanism consists of the order release plan and the order release control which is composed of two procedures. The experimental results show that the proposed order release mechanism is superior to other four order release mechanisms under overall simulation conditions of utilization rate, due-date allowances, and earliness/tardiness cost structures. In addition, the difference of total cost among the four dispatching rules is much more reduced in the proposed order release mechanism than in other release mechanisms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.6
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• pp.516-525
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• 1990

This paper proposes a hierarchical control algorithm for an efficient network management of a loosely-coupled system which consists of functional division and duplicating structure with a LAN to enhance reliability and availability. The algorithm is modeled using the Perti-net and verified with the reachability tree. Here, the proposed algorithm is compared with the purely centralized control algorithm and distributed control algorithm in terms of message traffic for the network management. The result shows that the message traffic related to system performance is as low as centralized control algorithm and the system availability is independent of a specific processor failure.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1257-1263
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• 1998

To realize a highly reliable satellite-base data distribution system efficiently, a hierarchical distributed control network which utilizers a sub control station(SCS) in addition to a hub and a user station(US) is proposed and evaluated. The results show that there exists an optimum number of sub control stations that minimizes the polling processing time as a parameter of the processing time ratio between US-SCS and SCS-CS links. From a viewpoint of the control network cost, it is shown that the cost can be less compared to the conventional one, when the communication cost between the US and SCS is slightly reduced.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2287-2293
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• 2009

Gas Chromatography-Mass Spectrometry (GC-MS) fingerprint analysis, Principle Components Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were introduced for quality assessment of Curcuma longa L. (C. longa). The GC-MS fingerprint method was developed and validated by analyzing 33 batches of samples of C. longa from different geographic locations. 18 chromatographic peaks were selected as characteristic peaks and their relative peak areas (RPA) were calculated for quantitative expression. Two principal components (PCs) were extracted by PCA. C. longa collected from Guizhou and Fujian were separated from other samples by PC1, capturing 71.83% of variance. While, PC2 contributed for their further separation, capturing 11.13% of variance. HCA confirmed the result of PCA analysis. Therefore, GC-MS fingerprint study with chemometric techniques provides a very flexible and reliable method for quality assessment of C. longa.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.496-500
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• 1998

Not merely running at the designated constant speed as the classical cruise control, the adaptive cruise control (ACC) maintains safe headway distance when the front is blocked by other vehicles. One of the most essential part of ACC System is the range sensor which can measure the position and speed of all objects in front continuously, ignore all irrelevant objects, distinguish vehicles in different lanes and lock on to the closest vehicle in the same lane. In this paper, the hierarchical object recognition algorithm (HORA) is proposed to process raw scanning laser data and acquire valid distance to target vehicle. HORA contains two principal concepts. First, the concept of life quantifies the reliability of range data to filter off the spurious detection and preserve the missing target position. Second, the concept of conformation checks the mobility of each obstacle and tracks the position shift. To estimate and predict the vehicle position Kalman filter is used. Repeatedly updated covariance matrix determines the bound of valid data. The algorithm is emulated on computer and tested on-line with our ACC vehicle.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.3
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• pp.210-216
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• 2006

In the rule based modeling, data partitioning plays crucial role be cause partitioned sub data set implies particular information of the given data set or system. In this paper, we present an empirical study result of the data pattern estimation to find underlying data patterns of the given data. Presented method performs crisp type clustering with given n number of data samples by means of the sequential agglomerative hierarchical nested model (SAHN). In each sequence, the average value of the sum of all inter-distance between centroid and data point. In the sequel, compute the derivation of the weighted average distance to observe a pattern distribution. For the final step, after overall clustering process is completed, weighted average distance value is applied to estimate range of the number of clusters in given dataset. The proposed estimation method and its result are considered with the use of FCM demo data set in MATLAB fuzzy logic toolbox and Box and Jenkins's gas furnace data.