• 제어로봇시스템학회논문지
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• 제17권12호
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• pp.1266-1272
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• 2011

For way-point tracking of an autonomous underwater vehicle, a state feedback controller was designed by using pole placement scheme in discrete time domain. In the controller, 4 state variables were used for regulating the depth of the vehicle in z direction, and 3 state variables, for steering the vehicle in xy plane. Assuming constant speed of AUV, we simplified the design of the way-point tracking system. The proposed controller was simulated by MATLAB/Simulink using 6 degree-of-freedom nonlinear model and its performance of way point tracking was shown to be fulfilled within 1 m, nevertheless the proposed controller is quite simple and easy to implement compared to sliding mode controller.

• 대한임베디드공학회논문지
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• 제10권4호
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• pp.257-264
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• 2015

For the tracking of the way-points of hovering AUV (HAUV), we suggest a simple PID controller. The way-points are designed to approach to a virtual underwater structure and the heading angles at each way-point are set to look at the structure in the face. The proposed controller consists of a vertical controller to maintain the depth and pitch angle, and a horizontal controller to move to the desired position as well as to adjust the heading angle of the HAUV. In the simulation using Matlab/Simulink, the HAUV with the proposed PID controller is shown to track all the way-points within 1 m range while maintaining proper heading angle at each way-point.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.162-167
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• 2003

In this paper, a novel feasible real-time system was researched for a differential driven wheeled autonomous mobile robot so that the mobile robot can move in a smooth, safe and elegant way. Least Square Minimum Path Planning was well used for the system to generate a smooth executable path for the mobile robot, and the point-to-point tracking algorithm was presented as well as its application in arbitrary path tracking. In order to make sure the robot can run elegantly and safely, trapezoidal speed was integrated into the point-to-point path tracking algorithm. The application to guest following for the autonomous mobile robot shows its wide application of the algorithm. The novel design was successfully proved to be feasible by our experiments on our mobile robot Interactive Robot Usher (IRU) in National University of Singapore.

• 제어로봇시스템학회논문지
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• 제19권8호
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• pp.661-666
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• 2013

A state feedback controller with integration of output error is proposed for way-point tracking of an AUV (Autonomous Underwater Vehicle). For the steering control on the XY plane, the proposed controller uses three state variables (sway velocity, yaw rate, heading angle) and the integral of the steering error, and for the depth control on the XZ plane, it uses four state variables (pitch rate, depth, pitch angle) and the integral of the depth error. From the simulation using Matlab/Simulink, we verify that the performance of the proposed controller is satisfactory within an error range of 1m from the target way-point for arbitrarily chosen sets of consecutive way-points.

• 한국항해항만학회지
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• 제42권2호
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• pp.87-96
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• 2018

A trajectory control system plays an important role in controlling motions of marine vehicle when a series of way points or a path is given. In this paper, a sliding mode control (SMC)-based trajectory tracking controller for marine vehicles is presented. A small-sized unmanned ship is considered as a control object. Both speed and heading angle of a ship should be controlled for tracking control. The common point of related researches was to separate ship's speed and heading angle in control methods. In this research, a new control law from a general sliding mode theory that can be applied to MIMO (multi input multi output) system is derived and both speed and heading angle of a ship can be controlled simultaneously. The propulsion force and rudder force are also applied in modeling stage to achieve accurate simulation. Disturbance induced by wind is also tackled in the dynamics considering robustness of the proposed control scheme. In the simulation, we employed a way-point method to generate ship's trajectory and applied the proposed control scheme to ship's trajectory tracking control. Our results confirmed that the tracking error was converged to zero, thus demonstrating the effectiveness of the proposed method.

• 한국정보통신학회논문지
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• 제19권3호
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• pp.636-644
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• 2015

이 논문에서는 CAM shift알고리즘과 8방향 탐색 위도우를 결합하여 객체의 추적 성능을 향상하는 방법과 추적에 이용되는 프레임의 수를 줄여 연산을 줄이는 방법을 제안한다. CAM shift는 대표적인 색상을 이용한 추적 방법이나 빠른 속도로 이동하는 물체를 추적하기 어려운 단점이 있다. 이를 해결하기 위해 추적 대상을 놓쳐버린 시점에서 마지막으로 추적에 성공한 시점의 정보를 이용하여 8방향 탐색을 실시하여 객체를 찾아 낸 후 CAM shift의 탐색 윈도우를 이동시켜 기존의 CAM shift로는 추적이 불가능한 고속 이동 물체에 대해서도 보다 정확한 추적이 가능하게 되었다. 또한 하드웨어의 발달로 초당 생산되어지는 프레임의 수가 증가하여 불필요한 연산이 증가하게 되었고, 이를 줄이기 위해 추적에 이용되는 프레임의 수를 줄여 연산을 줄여 이 전보다 효율을 높일 수 있었다.

• 제어로봇시스템학회논문지
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• 제20권2호
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• pp.132-137
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• 2014

In this paper, An LQR controller is proposed for way-point tracking of AUV (Autonomous Underwater Vehicle). The LQR controller aims at tracking a series of way-points which operator registers arbitrarily in advance. It consists of a depth controller and a steering controller and AUV's surge speed is assumed varying to consider the dynamic environment of the underwater. In order to show the performance, a conventional state feedback controller is compared with the proposed controller by the simulation using Matlab/Simulink. The parameters of AUV developed by the author's laboratory are used. In the simulation, we verify that the LQR controller can track all the way-points within 1 m error range under the varying surge speed, which proves the robustness of the LQR controller.

• 한국화재조사학회지
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• 제10권1호
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• pp.87-95
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• 2007

This paper is proposed a novel method to approximate the maximum power for a photovoltaic inverter system and tracking method. It is designed for power systems application and utilities. The proposed Maximum Power Point Tracking (MPPT) control has the advantage to provide a new simple way to approximate the optimal or rated voltage, the optimal or rated current and maximum power rating produced by a solar panel and the photovoltaic inverter. And this straightforward method will be named linear reoriented coordinates method (LRCM) with the advantage that Pmax and $V_{op}$ can be approximated using the same variable as the dynamic model without using complicate approximations or Taylor series. Furthermore tracking method is improved over 50% photovoltaic efficiency. This paper is proposed MPPT using LRMC and tracking method using weather condition of domestic moderate program technique. This paper is proposed the experimental results to verify the effectiveness of the new methods.

• 전자공학회논문지
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• 제49권11호
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• pp.103-109
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• 2012

논문에서는 천해역에서 운용가능한 소형의 자율무인잠수정 "BOTO"의 개발과 실해역 자율주행 성능시험에 관한 내용을 다룬다. BOTO의 개발을 위해 6자유도 운동방정식을 이용하여 시뮬레이션을 수행하였으며, 시뮬레이션 결과를 바탕으로 소형 자율무인잠수정을 개발하였다. 시뮬레이션에 사용되는 운동모델의 계수와 주행성능을 확인하기 위해 회류수조에서 저항계수 측정 시험도 수행하였다. 운동모델을 기반으로 무인잠수정의 선회반경 시뮬레이션과 수평면에서의 경로추종을 위한 알고리즘을 적용하여 시뮬레이션을 수행하였고, 설계된 제어기를 이용하여 실해역 자율주행시험을 수행하였다. 실해역 자율주행시험은 선회반경 측정시험과 경로점 추종시험을 실시하였으며, 실해역에서 목표 경로점을 잘 추종하는 것을 확인하였다.

• Journal of Mechanical Science and Technology
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• 제18권1호
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• pp.122-131
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• 2004

A constraint equation-based control law design for large angle attitude maneuvers of flexible spacecraft is addressed in this paper The tip displacement of the flexible spacecraft model is prescribed in the form of a constraint equation. The controller design is attempted in the way that the constraint equation is satisfied throughout the maneuver. The constraint equation leads to a two-point boundary value problem which needs backward and forward solution techniques to satisfy terminal constraints. An observer-based tracking control law takes the constraint equation as the input to the dynamic observer. The observer state is used in conjunction with the state feedback control law to have the actual system follow the observer dynamics. The observer-based tracking control law eventually turns into a stabilized system with inherent nature of robustness and disturbance rejection in LQR type control laws.