• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.139-142
• /
• 1997

In this paper, a robust controller is proposed to achieve an accurate tracking for an uncertain nonlinear plant with actuator dynamics. The extent of parameter uncertainty can be quantified by using linear parameterization technique. A switching controller is proposed to guarantee the global asymptotic stability of the plant. In order to eliminate the chattering caused by the switching controller, a smoothing controller is designed using the boundary layer technique around the sliding surface and guarantees the uniform ultimate boundedness of the tracking error.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
• /
• pp.153-156
• /
• 2003

This paper proposes a video tracking method for a deformable moving object using an active contour model. In order to decide the convergent directions of the contour points automatically, a new energy function based on a frame difference map and an updating rules of the frame difference map are presented. Experimental results on a set of synthetic and real image sequences showed that the proposed method can fully track a speedy deformable object while extracting the boundary of the object exactly in every frame.

• 대한전자공학회논문지
• /
• 제27권1호
• /
• pp.96-104
• /
• 1990

In this paper, a novel method of jig-saw puzzle matching is proposed using a modifided boundary matching algorithm without a priori knowledge for the matched puzzle. Specifically, a boundary tracking algorithm is utilised to segment each puzzle from low-resolution image data. Segmented puzzle is described via corner point, angle and distance between two adjacent coner point, and convexity and/or concavity of corner point. Proposed algorithm is implemented and tested in IBM PC and PC version vision system, and applied successfully to real jig-saw puzzles.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1810-1815
• /
• 2003

Sliding mode control with nonlinear interpolation in the boundary layer is proposed. A modified sigmoid function is used for nonlinear interpolation in the boundary layer and its parameter is tuned by a fuzzy logic controller. The fuzzy logic controller that takes the distance between the system state and the sliding surface as its input guides the choice of parameter of the modified sigmoid function and the parameter is on-line tuned. Owing to the decreased thickness, the proposed method has better tracking performance than the conventional linear interpolation method. To demonstrate its performance, the proposed control algorithm is applied to a simple nonlinear system model.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제20권1호
• /
• pp.83-106
• /
• 2016

This paper reviews and compares three different methods for modeling incompressible and immiscible ternary fluid flows: the immersed boundary, level set, and phase-field methods. The immersed boundary method represents the moving interface by tracking the Lagrangian particles. In the level set method, an interface is defined implicitly by using the signed distance function, and its evolution is governed by a transport equation. In the phase-field method, the advective Cahn-Hilliard equation is used as the evolution equation, and its order parameter also implicitly defines an interface. Each method has its merits and demerits. We perform the several simulations under different conditions to examine the merits and demerits of each method. Based on the results, we determine the most suitable method depending on the specific modeling needs of different situations.

• 로봇학회논문지
• /
• 제6권2호
• /
• pp.182-188
• /
• 2011

This paper describes a method of road tracking by using a vision and laser with extracting road boundary (road lane and curb) for navigation of intelligent transport robot in structured road environments. Road boundary information plays a major role in developing such intelligent robot. For global navigation, we use a global positioning system achieved by means of a global planner and local navigation accomplished with recognizing road lane and curb which is road boundary on the road and estimating the location of lane and curb from the current robot with EKF(Extended Kalman Filter) algorithm in the road assumed that it has prior information. The complete system has been tested on the electronic vehicles which is equipped with cameras, lasers, GPS. Experimental results are presented to demonstrate the effectiveness of the combined laser and vision system by our approach for detecting the curb of road and lane boundary detection.

• 제어로봇시스템학회논문지
• /
• 제6권1호
• /
• pp.8-14
• /
• 2000

In this paper, three adaptive sliding mode control algorithms, which self-tune both the sliding mode gain and the boundary layer thickness, are proposed. The first algorithm uses a gain adaptation rule is combined with the boundary layer thickness adaptatioin rule to satisfy the sliding condition. In the third algorithm, the computation burden of the second algorithm is reduced further, and therefore no extra cost is required for real-time implementation. Due to the mixed sliding mode gain and the boundary layer thickness adaptation scheme, the tracking error and the chattering of the control input can be reduced greatly.

• 인지과학
• /
• 제31권4호
• /
• pp.103-136
• /
• 2020

이 연구의 목적은 글읽기의 주요한 현상인 중심와주변 미리보기 효과(parafovea preview effect)의 중요성을 검증하고, 성인과 청소년을 대상으로 안구운동추적 실험을 통해 연령이 다른 두 집단의 중심와주변 미리보기 효과를 비교해 보고자 한다. 또한 안구운동 추적실험을 통해 얻은 결과자료를 단일경계 확산모형(diffusion model)의 시작점(starting point) 파라미터로 설명되는지 확인할 것이다. 실험은 경계선 기법(boundary technique)을 이용하여 중심와주변 정보처리를 관찰하였다. 실험 1에서는 중심와주변에 미리보기 정보로 고빈도 단어를 제시하는 것과 미리보기 정보를 차폐하는 것을 비교하였다. 실험 2에서는 중심와주변 미리보기 정보로 저빈도 단어를 제공하였고, 중심와주변 미리보기를 차폐한 것과 비교하였다. 두 실험 결과, 청소년 집단과 성인 집단에서 중심와주변에 정보가 주어졌을 때 중심와주변 미리보기 이득 효과를 확인하였다. 또한 중심와주변에 높인 정보 성질, 즉 단어의 빈도에 따라 두 집단의 첫고정시간, 단일고정시간, 주시시간에서 고정시간 차이를 살펴보았다. 두 실험에서 얻은 첫고정시간 데이터를 분위수로 나누고 단일경계 확산모형에 fitting한 결과, 중심와주변 정보처리가 시작점 파라미터로 설명되는 것을 확인하였다.

• 로봇학회논문지
• /
• 제6권1호
• /
• pp.86-96
• /
• 2011

The human-following is one of the significant procedure in human-friendly navigation of mobile robots. There are many approaches of human-following technology. Many approaches have adopted various multiple sensors such as vision system and Laser Range Finder (LRF). In this paper, we propose detection and tracking approaches for human legs by the use of a single LRF. We extract four simple attributes of human legs. To define the boundary of extracted attributes mathematically, we used a Support Vector Data Description (SVDD) scheme. We establish an efficient leg-tracking scheme by exploiting a human walking model to achieve robust tracking under occlusions. The proposed approaches were successfully verified through various experiments.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.85-86
• /
• 2006

In this paper, a nonlinear controller based on adaptive sliding-mode method which has a sliding surface vector including new boundary function is proposed and applied to a two-wheeled voiding mobile robot (WMR). This controller makes the welding point of WMR achieve tracking a reference point which is moving on a smooth curved welding path with a desired constant velocity. The mobile robot is considered in view of a kinematic model and a dynamic model in Cartesian coordinates. The proposed controller can overcome uncertainties and external disturbances by adaptive sliding-mode technique. To design the controller, the tracking error vector is defined, and then the new sliding is proposed to guarantee that the error vector converges to zero asymptotically. The stability of the dynamic system will be shown through the Lyapunov method. The simulations is shown to prove the effectiveness of the proposed controller.