Fuzzy-Based Speed Estimation for Navigation of Unmanned Robots

Jin, Gang-Gyoo,Lee, Hyun-Sik,Lee, Yun-Hyung,Lee, Young-Il,Park, Yong-Woon 제어로봇시스템학회 2010 Transaction on control, automation and systems eng Vol.12 No.1

This study presents a framework for assessing the navigation speed of unmanned robots by combining information extracted from the 3D world model of natural terrain with regional traversability based on the fuzzy technique. The proposed method divides the world model into several patches, extracts the slope and roughness of each terrain patch along four heading directions, and then uses them to evaluate the level of difficulty associated with the traversal. The slope is estimated through curved surface fitting, and roughness is obtained using fractal-based analysis together with another two RMS metrics. As navigation systems can cope with the imprecision and uncertainty of input data, we modify the Seraji's fuzzy-based measure to assess the traversability and navigation speed of each patch for path planning. The proposed method is tested on both fractal and real terrain to verify its effectiveness.

안티와인드업 기법을 가지는 PID 제어기의 EA 기반 동조

진강규(Gang-Gyoo Jin),박동진(Dong-Jin Park) 제어로봇시스템학회 2013 제어·로봇·시스템학회 논문지 Vol.19 No.10

Many practical processes in industry have nonlinearities of some forms. One commonly encountered form is actuator saturation which can cause a detrimental effect known as integrator windup. Therefore, a strategy of attenuating the effects of integrator windup is required to guarantee the stability and performance of the overall control system. In this paper, optimal tuning of a PID (Proportional-Integral-Derivative) controller with an anti-windup scheme is presented to enhance the tracking performance of the PID control system in the presence of the actuator saturation. First, we investigate effective anti-windup schemes. Then, the parameters of both the PID controller and the anti-windup scheme are optimally tuned by an EA (Evolutionary Algorithm) such as the IAE (Integral of Absolute Error) is minimized. A set of simulation works on two high-order processes demonstrates the benefit of the proposed method.

프랙탈 기법을 이용한 자연지형의 고도 복원

진강규(Gang-Gyoo Jin),김현준(Hyun-Jun Kim) 한국항해항만학회 2011 한국항해항만학회지 Vol.35 No.1

자연지형의 3D 디지털 지형모델(DTM)을 다루면서 소실된 셀의 데이터를 복원하거나, 저해상도의 DTM 이미지 일부를 컴퓨터 화면상에 확대표시 할 경우에는 존재하지 않는 데이터를 인위적으로 만들어줄 필요가 있다. 기존의 Bilinear법과 Bicubic법은 고도가 완만한 모델에는 잘 맞지만, 자연지형과 같이 무한의 상세함이 내재된 곳에는 부적합하다. 따라서 본 연구에서는 프랙탈 이론(Fractal theory)에 기초하여 자연지형을 보간하는 문제를 다루면서, 보간 전후 지형의 지형정보(프랙탈 차원과 표준편차)가 유지되는 한 방법을 제안한다. 이를 위해 DTM을 다수의 패치로 분할하고 프랙탈 기법으로 지형정보를 추출하고, 이 정보와 원래의 고도와 Random midpoint displacement법으로 보간한다. 제안된 알고리즘의 유효성을 확인하기 위해 가상의 프랙탈 지형을 만들어 시뮬레이션을 실시하고 기존의 방법과 비교한다. In this paper, we presents an algorithm which restores lost data or increases resolution of a DTM(Digital terrain model) using fractal theory. Terrain information(fractal dimension and standard deviation) around the patch to be restored is extracted and then with this information and original data, the elevations of cells are interpolated using the random midpoint displacement method. The results of the proposed algorithm are compared with those of the bilinear and bicubic methods on a fractal terrain map.

Fractal-Based Interpolation of TBD Cells

진강규(Gang-Gyoo Jin),하윤수(Yun-Su Ha),소명옥(Myung-Ok So),김현준(Hyun-Jun Kim) 한국마린엔지니어링학회 2010 한국마린엔지니어링학회 학술대회 논문집 Vol.2010 No.10

We presents an algorithm which interpolates lost data of a DTM(Digital terrain model) using fractal theory. Terrain information is extracted and then with this information and original data, the elevations of cells are interpolated using the random midpoint displacement method. The results of the proposed algorithm are compared with those of the bilinear and bicubic methods.

CSTR용 PID 제어기의 EA 기반 동조

진강규(Gang-Gyoo Jin) 한국지능시스템학회 2014 한국지능시스템학회논문지 Vol.24 No.3

연속교반탱크반응기, 담수화 플랜트, 증류탑, pH 중화 프로세스 등을 포함한 많은 산업용 프로세스들은 높은 비선형성과 시변 특성으로 인해 제어가 까다로워 보다 정밀하고 안정된 성능을 가지는 제어기를 설계하려는 많은 노력들이 있어 왔다. 본 논문에서는 기존 연구의 단점을 개선한 CSTR 프로세스의 농도제어용 PID 제어기를 동조하는 문제를 다룬다. 액추에이터 포화 문제를 극복하기 위해 PID 제어기에는 적분기 안티와인드업 피드백 루프가 구성되며, PID 제어기의 파라미터는 전체 제어 프로세스가 만족스러운 설정치 추종 성능을 가지도록 진화연산(EA)에 의해 동조된다. 제안하는 방법은 시뮬레이션을 통해 설정치 추종 성능, 외란 억제 성능과 파라미터 변동에 대한 강인성을 확인한다. Many industrial processes such as continuous stirred tank reactors(CSTRs), desalination plant, distillation columns, pH neutralization processes and so on exhibit highly nonlinear characteristic and time-varying behavior during operation. The control of such processes has been challenging to control engineers. Hence, a variety of forms of PID controllers and their tuning rules for industrial processes have been developed to guarantee the best performance. In this paper, a scheme that designs the practical PID controller with an anti-windup strategy incorporating with an evolutionary algorithm(EA) is presented for the concentration control of a nonisothermal CSTR. EA is used to tune the parameters of the overall PID control process with anti-windup by minimizing the integral of absolute error(IAE). Simulation works for reference tracking and disturbance rejecting performances and robustness to parameter changes show the feasibility of using the proposed method.

자율이동로봇의 안전주행을 위한 주행성 맵 작성

진강규(Gang-Gyoo Jin) 제어로봇시스템학회 2014 제어·로봇·시스템학회 논문지 Vol.20 No.4

This paper presents a method for developing a TM (Traversability Map) from a DTM (Digital Terrain Model) collected by remote sensors of autonomous mobile robots. Such a map can be used to plan traversable paths and estimate navigation speed quantitatively in real time for robots capable of performing autonomous tasks over rough terrain environments. The proposed method consists of three parts: a DTM partition module which divides the DTM into equally spaced patches, a terrain information module which extracts the slope and roughness of the partitioned patches using the curve filing and the fractal-based triangular prism method, and a traversability analysis module which assesses traversability incorporating with extracted terrain information and fuzzy inference to construct a TM. The potential of the proposed method is validated via simulation works over a set of fractal DTMs.

Tracking Controller Design fur Systems with Delay in the Control

Jin, Gang-Gyoo,Oh, Sea-June,Ha, Joo-Shik Korean Society of Marine Engineers 1990 한국마린엔지니어링학회지 Vol.14 No.3

제어입력에 무시하지 못할 정도의 시간지연이 있는 시스템에 있어서의 강인한 제어기를 설계하고 실현하는 문제를 다루었다. 본 논문에서 제안하는 제어기를 설계하기 위하여 전향 방향에 적분기 하나를 추가하고 빠른 응답 특성을 주기 위하여 상태변수 $x_1$ 대신 오차신호 y-$y_r$를 궤환 하도록 하였으며 여기서 일어날 수 있는 오우버슈터를 줄이기 위하여 Integral reset scheme을 이용하였다. 제어기 실현을 위하여서는 궤환되어지는 모든 상태변수의 측정이 요구되나 실제 제어 문제에서는 경제적, 기술적인 문제로 그렇지 못하므로 측정 불가능한 상태변수는 상태관측기를 구성하여 이용하도록 하였다.

지형 고도 맵으로부터 기울기와 거칠기 추출 방법

진강규(Gang-Gyoo Jin),이현식(Hyun-Sik Lee),이윤형(Yun-Hyung Lee),소명옥(Myung-Ok So),신옥근(OK-Keun Shin),채정숙(Jeong Sook Chae),이영일(Young-Il Lee) 제어로봇시스템학회 2008 제어·로봇·시스템학회 논문지 Vol.14 No.9

Recently, the interests in the development and application of unmaned robots are increasing in various fields including surveillance and reconnaissance, planet exploration, and disaster relief Unmaned robots are usually controlled from distance using radio communications but they should be equipped with an autonomous travelling function to cope with unexpected terrains and obstacles. This means that they should be able to evaluate terrain’s characteristics quantitatively using mounted sensors so as to traverse harsh natural terrains autonomously. For this purpose, this paper presents a method for extracting terrain information, that is, slope and roughness from elevation maps as a prior step of traversability analysis. Slope is extracted using the curve fitting based on the least squares method and roughness using three metrics and their weighted average. The effectiveness of the proposed method is verified on both a fractal map and the world model map of a real terrain.

Kalman Tracking Filter for Estimating Target Position

陳康奎(Gang-Gyoo Jin),河注植(Joo-Shik Ha),朴進吉(Jin-Gil Park) 대한전기학회 1986 전기학회논문지 Vol.35 No.11

무인로봇의 주행성 분석을 위한 지형정보 추출

진강규(Gang-Gyoo Jin),이현식(Hyun-Sik Lee),이윤형(Yun-Hyung Lee),소명옥(Myung-Ok So),채정숙(Jeong Sook Chae),이영일(Young-Il Lee) 한국지능시스템학회 2008 한국지능시스템학회 학술발표 논문집 Vol.18 No.1

Recently, the development and application of unmaned robots are increasing in various fields including surveillance and reconnaissance, planet exploration and disaster relief. Unmaned robots are usually controlled from distance using radio communications but they should be equipped with autonomous travelling function to cope with unexpected terrains and obstacles. This means that unmanned robots should be able to evaluate terrain's characteristics quantitatively using mounted sensors so as to traverse harsh natural terrains autonomously. For this purpose, this paper presents an algorithm for extracting terrain information from elevation maps as an early step of traversability analysis. Slope and roughness information are extracted from a world terrain map based on least squares method and fractal theory, respectively. The effectiveness of the proposed algorithm is verified on both fractal and real terrain maps.