This study explores the course tracking control problem of unmanned surface vessels (USVs) under the influence of actuator faults and internal and external uncertainties. In the control strategy desig n, we first model the unknown dynamics and use adaptive technology to construct an online appro ximator to compensate for the unknown dynamics of the system. Under the framework of adaptive backstepping, a robust adaptive course tracking control scheme is constructed. This control strategy does not require any prior knowledge of the model in advance. The stability analysis of the theoret ical mathematical derivation of the control strategy was conducted based on Lyapunov stability theo ry. Finally, the effectiveness of the control strategy proposed in this paper was verified through sim ulation.

A robust adaptive control approach is proposed for underactuated surface ship linear path-tracking control system based on the backstepping control method and Lyapunov stability theory. By employing T-S fuzzy system to approximate nonlinear uncertainties of the control system, the proposed scheme is developed by combining “dynamic surface control” (DSC) and “minimal learning parameter” (MLP) techniques. The substantial problems of “explosion of complexity” and “dimension curse” existed in the traditional backstepping technique are circumvented, and it is convenient to implement in applications. In addition, an auxiliary system is developed to deal with the effect of input saturation constraints. The control algorithm avoids the singularity problem of controller and guarantees the stability of the closed-loop system. The tracking error converges to an arbitrarily small neighborhood. Finally, MATLAB simulation results are given from an application case of Dalian Maritime University training ship to demonstrate the effectiveness of the proposed scheme.

태양광 패널로부터 출력을 최대로 얻기 위해서는 신뢰성이 높은 태양광 추적 장치가 설계되어야 한다. 본 논문에서는 LabVIEW 프로그램을 이용하여 퍼지 제어를 기반으로 구현한 2축 태양광 추적 장치 시스템을 제작하여 그 성능에 대해서 알아보았다. 태양광 패널의 움직임을 제어하기 위한 구현된 퍼지 의사결정 시스템의 사용자 인터페이스를 통하여 모든 파라미터를 제어하고 확인할 수 있는 지능제어기와 기계적인 구동부분의 설계가 연구의 중심이 되고 있다. 실제 태양광 추적시스템을 개발하여 환경, 날씨, 계절 및 빛 상태와 같은 영향에 대해서 분석하였다. 태양광 추적장치는 실제 상황에서 시험하였고 시스템 동작과 관련된 모든 변수들은 기록되고 분석되었다. 제안한 태양광 추적시스템을 활용할 경우 고정식 패널에 비해 날씨에 따라 다르지만 최대 약 38% 정도의 더 높은 효율을 얻을 수 있어 자동으로 추적할 때 매우 좋은 결과를 얻을 수 있었다.

최근에 들어 3D 입체영상 기술은 의료, 건축, 디자인 및 게임 등 다양한 분야에서 활용되고 있으며, 마치 사용자가 실제 주변 환경과 상호작용을 하고 있는 것처럼 느끼게 해 주는 가상현실을 적용한 기술이 일반화되고 있는 추세이다. 입체영상을 제어하기 위한 종래 방법으로서는 마우스, 키보드 등의 도구를 사용하여 제어 신호를 입력하는 방법을 생각해 볼 수 있는데 이러한 방법은 사용자가 도구를 사용하여 입체영상을 제어해야 하는 불편함이 있었고 도구 사용의 오류로 인하여 입체영상을 원하는 대로 제어하기가 쉽지 않을 수도 있다는 문제점이 있다. 뿐만 아니라 이러한 제어 방법은 사용자가 콘텐츠를 사실감 있게 느끼지 못하게 되는 중요한 원인이기도 하다. 따라서 본 논문에서는 마우스, 키보드 등의 도구를 사용하지 않고도 사용자의 자연스러운 움직임만으로 편리하고 사실감 있게 콘텐츠를 제어할 수 있는 시스템을 개발하였다. 본 논문에서 제시한 기술을 활용하여 입체영상 게임, 외과 수술 훈련, 군사 훈련, 조종사 시뮬레이션 등 다양한 3D 콘텐츠를 사실감 있게 제어할 수 있다.

Tracking is an experimental paradigm that can be used to study information processing in continuous movements involving accurate, ongoing control of motor performance. The purpose of this study was to identify the effects of knee tracking performance. Six patients with hemiplegia and six age-matched controls participated in the study. The tracking test was administrated. It was composed with regular ranges of to and randomized range .2 to .4 Hz. Using the Mann-Whitney U test, a comparison was made between subjects who had suffered from stroke and subjects who were well coordinated. The Wilcoxon Matched Pairs Signed Ranks Test was used to compare and analyze the paretic and nonparetic sides of the stroke patients. The results of study were as follows: accuracy index of the tracking test was significantly higher on the control side than paretic and nonparetic sides. Accuracy index scores were significantly higher for nonparetic sides with stroke compared with paretic sides with stroke. This study shows tracking is impaired in paretic and nonparetic knee of subjects with stroke.

There have been continuous efforts on automating welding processes. This automation process could he said to fall into two categories, weld seam tracking and weld quality evaluation. Recently, the attempts to achieve these two functions simultaneously arc on the increase. For the study presented in this paper, a vision sensor is made, a vision system is constructed and using this, the 3 dimensional geometry of the head is measured on-line. For the application as in welding, which is the characteristic of nonlinear process, a fuzzy controller is designed. And with this, an adaptive control system is proposed which acquires the bead height and the coordinates of the point on the bead along the horizontal fillet joint, performs seam tracking with those data, and also at the same time, controls the bead geometry to a uniform shape. A communication system, which enables the communication with the industrial robot, is designed to control the bead geometry and to track the weld seam. Experiments are made with varied offset angles from the pre-taught weld path, and they showed the adaptive system works favorable results.

We have improved the control and driving system of 16' reflector at Kwanak Observatory at Seoul National University, by completing encoder unit, and by developing programs for correction of errors resulting from hardware defects. The hardware defects of this telescope system are the large backlash and the nonuniform tracking and pointing. The telescope pointing accuracy for RA is improved to a few arc minutes, and that for DEC is several tens of arc minutes. The guiding error is improved to 0.7 arcsec/minute, allowing up to 3 minutes exposure for CCD imaging under typical seeing conditions at the Observatory.

This paper presents a dynamic compensation methodology for robust trajectory tracking control of uncertain robot manipulators. To improve tracking performance of the system, a full model-based feedforward compensation with continuous VS-type robust control is developed in this paper(i.e,. robust decentralized adaptive control scheme). Since possible bounds of uncertainties are unknown, the adaptive bounds of the robust control is used to directly estimate the uncertainty bounds(instead of estimating manipulator parameters as in centralized adaptive control0. The global stability and robustness issues of the proposed control algorithm have been investigated extensively and rigorously via a Lyapunov method. The presented control algorithm guarantees that all system responses are uniformly ultimately bounded. Thus, it is shown that the control system is evaluated to be highly robust with respect to significant uncertainties.

A differential drive wheeled robot is a kind of mobile robot suitable for indoor navigation. Model predictive control is an optimal control technique with various advantages and can achieve excellent performance. One of the main advantages of model predictive control is that it can easily handle constraints. Therefore, it deals with realistic constraints of the mobile robot and achieves admirable performance for trajectory tracking. In addition, the intention of the robot can be properly realized by adjusting the weight of the cost function component. This control technique is applied to the local planner of the navigation component so that the mobile robot can operate in real environment. Using the Robot Operating System (ROS), which has transcendent advantages in robot development, we have ensured that the algorithm works in the simulation and real experiment.

In a four-wheel independent drive platform, four wheels and motors are connected directly, and the rotation of the motors generates the power of the platform. It uses a skid steering system that steers based on the difference in rotational power between wheel motors. The platform can control the speed of each wheel individually and has excellent mobility on dirt roads. However, the difficulty of the straight-running is caused due to torque distribution variation in each wheel’s motor, and the direction of rotation of the wheel, and moving direction of the platform, and the difference of the platform’s target direction. This paper describes an algorithm to detect the slip generated on each wheel when a four-wheel independent drive platform is traveling in a harsh environment. When the slip is detected, a compensation control algorithm is activated to compensate the torque of the motor mounted on the platform to improve the trajectory tracking performance of the platform. The four-wheel independent drive platform developed for this study verified the algorithm. The wheel slip detection and the compensation control algorithm of the platform are expected to improve the stability of trajectory tracking.

Unlike normal wheels, the Mecanum wheel enables omni-directional movement regardless of the orientation of a mobile robot. In this paper, a robust trajectory tracking control method is developed based on the dynamic model of the Mecanum wheel mobile robot in order that the mobile robot can move along the given path in the environment with disturbance. The method is designed using the impedance control to make the mobile robot to track the path, and the integral sliding mode control for robustness to disturbance. The good performance of the proposed method is verified using the MATLAB /Simulink simulation and also through the experiment on an actual Mecanum wheel mobile robot. In both the simulation and the experimentation, we make the mobile robot move along a reference trajectory while maintaining the robot's orientation at a constant angle to see the characteristics of the Mecanum wheel.

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.

As the Photovoltaic system market increases, various technologies are emerging to improve system operation efficiency. Such additional systems of the power generation system are generally referred to as ‘Balance of System’, for example a panel cooling, a panel cleaning and a panel angle adjusting apparatus. In this paper, we discuss an algorithm to calculate the target temperature of cooling in response to changes in the installation environment conditions of the power generation system so that the efficiency improvement rate target set by the user can be achieved with respect to the control method of the cooling water injection system among various panel cooling apparatuses. In order to calculate the target temperature of cooling, the output enhancement coefficient is calculated experimentally based on the temperature change according to the solar radiation condition of the PV panel, and the required reduction temperature of each irradiation condition is calculated considering the efficiency improvement rate. In addition, the efficiency improvement ratio is calculated considering the installation condition of the general power generation system without a separate control group. The thermal performance coefficient of the PV panel test body for calculating the expected temperature of the PV panel is calculated experimentally. The target temperature of cooling is calculated as the sum of the expected temperature of the PV panel and the required reduction temperature, and the injection system that tracks the target temperature by cooling water injection is constructed and compared with the power generation improvement rate and the user setting efficiency improvement rate.

Conventional path tracking methods designed for two-wheeled differential drive robots are not suitable for omni-directional robots. In this study, we present a controller which can accomplish more accurate path tracking and orientation correction by exploiting the unconstrained movement capability of omni-directional robots. The proposed controller is proven to be stable using a Lyapunov stability criterion. Various experiments in real environments show that performance of path tracking and orientation correction has improved in the proposed controller.

In this paper, we proposed visual information to provide a highly maneuverable system for a tele-operator. The visual information image is bird’s eye view from UFR(Unmanned Flying Robot) shows around UGR(Unmanned Ground Robot). We need UGV detection and tracking method for UFR following UGR always. The proposed system uses TLD(Tracking Learning Detection) method to rapidly and robustly estimate the motion of the new detected UGR between consecutive frames. The TLD system trains an on-line UGR detector for the tracked UGR. The proposed system uses the extended Kalman filter in order to enhance the performance of the tracker. As a result, we provided the tele-operator with the visual information for convenient control.

컨테이너의 신속한 이송 및 처리는 작업시간 단축에 의한 비용절감을 의미하므로 항만에서는 가능한 작업효율을 향상시키기 위해 다양한 노력이 추진되고 있다. 1990년대 중반부터 RMGC 및 RTGC 등의 크레인이 개발되어 컨테이너 이송 및 적재를 위한 필수장비로 널리 이용되고 있다. 특히 RTGC는 타이어 구동방식이므로 주행환경에 크게 제약을 받지 않는 장점도 있으나, 타이어 슬립, 타이어에 의한 샤시의 기울어짐 등 설정된 경로를 고정도로 주행해야 하는 목적달성에 장애가 되는 요인도 많아 레일 위를 주행하는 RMGC에 비해 자동화가 용이하지 않다. 이것은 무인 RTGC 시스템 구축을 어렵게 하는 가장 큰 요인이 되어 이와 관련한 기술개발 또한 미비한 수준에 이르고 있다. 따라서 본 논문에서 RTGC의 무인자동화에 있어서 가장 기초단계라고 볼 수 있는 수학적 모델링을 기반으로 한 고정도 주행제어기를 설계하고자 한다. 먼저 제어대상인 RTGC의 주행에 따른 운동특성을 분석하여 모델링을 수행한다. 기본적인 주행성능을 달성하기 위한 주행제어기를 설계하고 시뮬레이션을 통해 설계된 제어기의 유용성을 확인하도록 한다.