• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.114-121
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• 2010

As a vehicle speed increases, more vibration energy is transmitted from chassis to a driver. Current isolation system for the driver's seat by damping control can reduce the transmitted vibration energy near resonance area. But in higher frequency region than natural frequency multiplied by $\sqrt{2}$, the vibration energy transmitted to the driver has a tendency to be increased. Therefore, the method by natural frequency reduction of the system is preferred to increase the effectiveness of the anti-vibration. However, the natural frequency could not be freely reduced due to the nature of the isolation system structure. A new passive suspension system to reduce the natural frequency is proposed. The theoretical analysis and experimental results show better vibration attenuation compared with the current isolation system.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.43-48
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• 2007

For exposure systems, very accurate alignment between the mask and the substrate is indispensable. In this paper, an automatic alignment system using machine vision for exposure systems is described. Machine vision algorithms are described in detail including extraction of an alignment mark's center position and camera calibration. Methods for extracting parameters for alignment are also presented with some compensation techniques to reduce alignment time. Our alignment system was implemented with a vision system and motion control stages. The performance of the alignment system has been extensively tested with satisfactory results. The performance evaluation shows alignment accuracy of lum within total alignment time of about $2{\sim}3$ seconds including stage moving time.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.3-8
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• 2007

This paper presents a set of techniques used in a real-time visual surveillance system. The system is implemented on a low-cost embedded DSP platform that is designed to work with stationary video sources. It consists of detection, a tracking and a classification module. The detector uses a statistical method to establish the background model and extract the foreground pixels. These pixels are grouped into blobs which are classified into single person, people in a group and other objects by the dynamic periodicity analysis. The tracking module uses mean shift algorithm to locate the target position. The system aims to control the human density in the surveilled scene and detect what happens abnormally. The major advantage of this system is the real-time capability and it only requires a video stream without other additional sensors. We evaluate the system in the real application, for example monitoring the subway entrance and the building hall, and the results prove the system's superior performance.

• International Journal of Korean Welding Society
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• v.2 no.2
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• pp.32-35
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• 2002

In this paper, an intelligent system to determine welding parameters for each pass and welding position in pipeline welding based on one database and FEM model, two BP neural network models and a C-NN model was developed and validated. The preliminary test of the system has indicated that the developed system could determine welding parameters fur pipeline welding quickly, from which good weldments can be produced without experienced welding personnel. Experiments using the predicted welding parameters from the developed system proved the feasibility of interface standards and intelligent control technology to increase productivity, improve quality, and reduce the cost of system integration.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.677-688
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• 2008

In this paper, the general problem of impedance control for a robotic manipulator with a moving flexible base is addressed. Impedance control imposes a relation between force and displacement at the contact point with the environment. The concept of impedance control of flexible base mobile manipulator is rather new and is being considered for first time using singular perturbation and new sliding mode control methods by authors. Initially slow and fast dynamics of robot are decoupled using singular perturbation method. Slow dynamics represents the dynamics of the manipulator with rigid base. Fast dynamics is the equivalent effect of the flexibility in the base. Then, using sliding mode control method, an impedance control law is derived for the slow dynamics. The asymptotic stability of the overall system is guaranteed using a combined control law comprising the impedance control law and a feedback control law for the fast dynamics. As first time, base flexibility was analyzed accurately in this paper for flexible base moving manipulator (FBMM). General dynamic decoupling, whole system stability guarantee and new composed robust control method were proposed. This proposed Sliding Mode Impedance Control Method (SMIC) was simulated for two FBMM models. First model is a simple FBMM composed of a 2 DOFs planar manipulator and a single DOF moving base with flexibility in between. Second FBMM model is a complete advanced 10 DOF FBMM composed of a 4 DOF manipulator and a 6 DOF moving base with flexibility. This controller provides desired position/force control accurately with satisfactory damped vibrations especially at the point of contact. This is the first time that SMIC was addressed for FBMM.

• Steel and Composite Structures
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• v.51 no.5
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• pp.473-485
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• 2024

This paper proposes a composite form of fuzzy adaptive control plan based on a robust observer. The fuzzy 2D control gains are regulated by the parameters in the LMIs. Then, control and learning performance indices with weight matrices are constructed as the cost functions, which allows the regulation of the trade-off between the two performance by setting appropriate weight matrices. The design of 2D control gains is equivalent to the LMIs-constrained multi-objective optimization problem under dual performance indices. By using this proposed smart tracking design via fuzzy nonlinear criterion, the data link can be further extended. To evaluate the performance of the controller, the proposed controller was compared with other control technologies. This ensures the execution of the control program used to track position and trajectory in the presence of great model uncertainty and external disturbances. The performance of monitoring and control is verified by quantitative analysis. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Therefore, the goal is believed to achieved in the near future by the ongoing development of AI and control theory.

• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.166-173
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• 2014

Recently, small quadcopters have been widely used in various areas ranging from military to entertainment applications because interest in the quadcopter increases. Especially, the research on swarm flight which control quadcopters simultaneously without any collision can increase success probability of a important mission. In addition the swarm flight can be applied for demonstrating choreographed aerial maneuvers such as dancing and playing musical instruments. In this paper, we introduce multiple AR.Drone control system based on motion capture for indoor environment in which quadcopters can recognize current position each other and perform scenario based mission.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.55-63
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• 2003

An attitude control system using reaction thrusters for the upper stage of a launch vehicle is considered. The thruster configuration (position and direction) determines control system response, fuel consumption, effective torque and system fault tolerance. We propose a procedure for finding the optimal thruster configuration with desired control effectiveness over the range of selected torque commands. An optimization technique called Particle Swarm Optimization is used for the numerical experiments. The validity of the solution is checked through computer simulations.

• Journal of Ocean Engineering and Technology
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• v.13 no.3B
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• pp.38-46
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• 1999

Increasing stringent emissions legislation and requirement of more effective energy used for diesel engine demand the fine control of the fuel injection system. Recently, the electromagnetic fuel injection control system for diesel engine is tried to realize the optimum diesel combustion by the feel back sensing as optical signal of combustion flame. The photo detectors were made for the feed back signal of electromagnetic fuel injection control for small DI diesel engine. Their abilities to detect defining combustion events were examined. By evaluating test results, it was shown that the wider acceptable optical range design of optical probe window face, and selection of installation position and installation method of detector were important point for improving sensing ability. The detector was shown to detect start and end of diffused combustion and maximum point of flame intensity impossible for pressure sensor, and also shown that the maximum point of flame intensity was 75% of accumulated heat release point within the experimental conditions.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.4
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• pp.213-221
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• 2017

Utilizing the existing polishing robot prevents unrestricted change of direction, driving, and identification of driving pathway. To overcome this barrier, driving mechaism has been designed with Omniwheels with encoders and RSSI method of beacon system has been utilized to identify the driving path by position recognition. Due to the wheel characteristics, the Omniwheel mobile robot generates greater slip than the conventional mobile robot, which reduces its driving accuracy. Therefore, to improve the driving accuracy, the localization is conducted through the fusion of encoder and RSSI of beacon data to compensate for the errors caused by Dead Reckoning and inaccuracy of sensors. Finally, the localization accuracies of the proposed and conventional indoor localization method are compared to show effectiveness of the proposed driving control for a polishing robot.