• Journal of Institute of Control, Robotics and Systems
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• v.7 no.7
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• pp.597-604
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• 2001

Recently, the study of the moving sliding mode in the variable structure control is in progress ac-tively. The conventional time-invariant sliding model control can\`t guarantee the sliding mode in the reaching phase, which is robust against the uncertainty. But with the time-varying method, the controller makes the states track the desired trajectories and keeps the sliding mode. Nevertheless, the piecewise continuous method of the past still has the reaching mode. Thus we propose the continuously moving sliding surface by the fuzzy algorithm. The proposed algorithm is made of the fuzzy rule considering both the error and the error velocity, and may apply to the entire phase plane without sacrificing sliding mode. Especially the proposed scheme can rotate tot he slope-decreasing direction, needless to say rotating to the slope-increasing direction. For showing that the proposed controller guarantees the sliding model and ensures the robustness, we apply the proposed method to the two-link robot manipulator simulation.

• KIEAE Journal
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• v.10 no.6
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• pp.3-10
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• 2010

The subject is to find green roofs' location as stepping stones in green-network in fine scale. The study site is Junggu, Seoul, which has core areas(Bukaksan and Namsan) and green areas(parks, etc.). Through literature review, the closer to core areas and green areas, target species reach green roof easier, and target species must be avifauna(flying species) and high class in food chain, because of possibility of reaching. So, Great Tits, inhabited in Namsan and urban bird, is target species. The location standard of green roofs, realized birds' reaching distance, consists of home range(horizontal range and vertical range) and roof-greening capable area. The green roofs' distribution of location was resulted through GIS analysis of feasible site finding, and classified with weight of score. In discussion, Namsan gives more effect to locate green roofs than Bukaksan does and selected buildings which are grouped in some parts need to be managed with group, green roof district.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.807-809
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• 1995

In this paper, a design of the sliding mode controller using neural networks is proposed. The overall control system consists of a neural network controller and a reaching mode control input. The neural network controller approximates the equivalent control on the sliding surface and reaching mode control input is used to bend the entire system trajectories toward the sliding surface. The proposed controller is applied to the position control of a DC servo motor.

• Elastomers and Composites
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• v.53 no.3
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• pp.168-174
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• 2018

Natural rubber (NR) and bromo-isobutylene-isoprene rubber (BIIR) were compounded with other formulation chemicals through polymer blending via a mechanical mixing method. After rubber vulcanization by hot-press compression molding, the cure characteristics, mechanical properties, and ozone resistance of the NR/BIIR blends were measured. As the BIIR content increased, the maximum torque of the blends decreased, while the optimum cure time and scorch time tended to increase. Furthermore, the hardness of the blends increased with increasing BIIR content, reaching the maximum value at 75 wt% BIIR, and decreased with a further increase in the BIIR loading. The tensile strength and elongation at break decreased with an increase in the BIIR content, reaching the minimum value at 75 wt% BIIR, and increased with a further increase in the BIIR content. In the ozone resistance test, cracks were not generated when the BIIR content was more than 75 wt%.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.2
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• pp.89-96
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• 2002

A new chattering free PD-sliding mode hybrid control scheme is proposed for robot manipulators. This hybrid controller is composed of a PD controller and a semi-continuous sliding mode controller. It has a good robust performance in reaching mode which does not possess invariance property of sliding mode, and has chattering free characteristics in sliding mode. Thus, the PD-sliding mode hybrid controller has a good robust performance in the whole region. It is shown that the proposed control has a good transient response and trajectory tracking performance for a 2-link SCARA robot manipulator.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.1
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• pp.51-59
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• 1990

In this paper, a new variable structure control algorithm is proposed to reduce the reaching time on a phase plane. In the new method, a term proportional to the magnitude of the switching variables is added to the Morgan and Ozguners algorithm. When this algorithm is applied to second order systems the simulation results show that the new approach of the control algorithm is more effective than morgan's algorithm.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.8
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• pp.471-481
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• 2003

The acts of biological immune system are similar to the navigation for autonomous mobile robots under dynamically changing environments. In recent years, many researchers have studied navigation algorithms using artificial immune networks. Conventional artificial immune algorithms consist of an obstacle-avoidance behavior and a goal-reaching behavior. To select a proper action, the navigation algorithm should combine the obstacle-avoidance behavior with the goal-reaching behavior. In this paper, the neural network is employed to combine the behaviors. The neural network is trained with the surrounding information. the outputs of the neural network are proper combinational weights of the behaviors in real-time. Also, a velocity control algorithm is constructed with the artificial immune network. Through a simulation study and experimental results for a autonomous mobile robot, we have shown the validity of the proposed navigation algorithm.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.335-337
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• 1993

An integral-augmented variable structure system is suggested for the control of an uncertain SISO systems without the reaching phase problems. The integral-augmented sliding surface is defined in order to remove the reaching phase, then it is designed using the optimal technique. The example results show the effectiveness of the algorithm.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.4
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• pp.315-324
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• 2000

This paper presents an efficient dynamic programming(DP) method, so called EDPAS (Efficient Dynamic Programming Algorithm for Signal), for optimally controlling traffic signal in real-time mode at a single intersection. The objective of EDPAS is to minimize total vehicle delay. It applies reaching method to solve forward DP functional equation, which does not need any priori knowledge on the states of DP network. Two acceleration techniques within reaching method are the main feature of EDPAS. They are devised to eliminate inferior DP states by comparing between states and maintaining incumbent value, resulting in a great amount of computational efficiency. An example is shown to verify the advantage of EDPAS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.605-611
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• 2000

Presented in this paper is a new method of identifying the critical speed of rotor-bearing systems without actually reaching at the critical speed itself. Using the method, it is not only possible to calculate the critical speed by measuring a series of rotor responses at much lower rotating speeds away from and without reaching at the critical speeds but also the damping ratio and eccentricity of the system can be identified at the same time. Two types of test rotors were tested on the Rotor Dynamics Test Facility at the Rotordynamics Lab., KIMM, and the theory has been confirmed experimentally. The method can be adopted to monitor changes of the dynamic characteristics of critical rotating machinery before and after overhauls, repairs, exchanges of various parts, or to detect trends of direction of subtle changes in the dynamic characteristic parameters over a long periods of time.