• 제목/요약/키워드: Target Tracking Controller

검색결과 84건 처리시간 0.025초

Analysis of Threat Model and Requirements in Network-based Moving Target Defense

  • Kang, Koo-Hong;Park, Tae-Keun;Moon, Dae-Sung
    • 한국컴퓨터정보학회논문지
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    • 제22권10호
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    • pp.83-92
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    • 2017
  • Reconnaissance is performed gathering information from a series of scanning probes where the objective is to identify attributes of target hosts. Network reconnaissance of IP addresses and ports is prerequisite to various cyber attacks. In order to increase the attacker's workload and to break the attack kill chain, a few proactive techniques based on the network-based moving target defense (NMTD) paradigm, referred to as IP address mutation/randomization, have been presented. However, there are no commercial or trial systems deployed in real networks. In this paper, we propose a threat model and the request for requirements for developing NMTD techniques. For this purpose, we first examine the challenging problems in the NMTD mechanisms that were proposed for the legacy TCP/IP network. Secondly, we present a threat model in terms of attacker's intelligence, the intended information scope, and the attacker's location. Lastly, we provide seven basic requirements to develop an NMTD mechanism for the legacy TCP/IP network: 1) end-host address mutation, 2) post tracking, 3) address mutation unit, 4) service transparency, 5) name and address access, 6) adaptive defense, and 7) controller operation. We believe that this paper gives some insight into how to design and implement a new NMTD mechanism that would be deployable in real network.

실제 날씨를 고려한 PV-MPPT 제어기의 최적 주기와 변량전압 (Optimum Control Period and Perturbation Voltage for PV-MPPT Controller Considering Real Wether Condition)

  • 류단비;김용중;김효성
    • 전력전자학회논문지
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    • 제25권1호
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    • pp.1-5
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    • 2020
  • Solar power generation systems require maximum power point tracking (MPPT) control to operate PV panels at their maximum power point (MPP). Most conventional MPPT algorithms are based on the slope-tracking concept. A typical slope-tracking method is the perturb and observe (P&O) algorithm. The P&O algorithm measures the current and voltage of a PV panel to find the operating point of the voltage at which the calculated power is maximized. However, the measurement error of the sensor causes irregularity in the calculation of the generated power and voltage control. This irregularity leads to the problem of not finding the correct MPP operating point. In this work, the power output of a PV panel based on the P&O algorithm is simulated by considering the insolation profiles from typical clear and cloudy weather conditions and the errors of current and voltage sensors. Simulation analysis suggests the optimal control period and perturbation voltage of MPPT to maximize its target efficiency under real weather conditions with sensor tolerance.

Nonholonomic 이동로봇의 호밍과 장애물 회피 알고리즘 (A Homing and Obstacle Avoidance Algorithm for Nonholonomic Mobile Robots)

  • 공성학;서일홍
    • 대한전기학회논문지:시스템및제어부문D
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    • 제51권12호
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    • pp.583-595
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    • 2002
  • Homing operation can be defined as a series of actions which are necessary for a mobile robot to move from the current position with any arbitrary orientation to a desired position with a specified orientation, while avoiding possible obstacles. In this paper, a homing and obstacle avoidance algorithm for nonholonomic mobile robots is proposed. The proposed algorithm consists of a local goal generator, a discrete state controller, and local path tracking controller based on Aicardi's path following algorithm. In the discrete state controller, 4 states are defined according to the environmental conditions and 4 desired high-level command for the states are given as follows: avoid, wander, home and homing zones. The proposed local goal generator is designed to generate the desired local path by using weighted distance transforms which are newly made to satisfy the nonholonomic constraints of mobile robots. Here, subgoals are also found as vertices of the desired local path. To demonstrate result effectiveness and applicability of the proposed algorithm, computer simulations are illustrated and experimental results for a real mobile robot system are also provided.

단순구조 퍼지논리시스템을 이용한 이동 로봇의 주행 제어기 설계 (Design of Simple-structured Fuzzy Logic System based Driving Controller for Mobile Robot)

  • 최병재;김성
    • 한국지능시스템학회논문지
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    • 제22권1호
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    • pp.1-6
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    • 2012
  • 이동로봇에 관한 연구가 널리 진행되고 있다. 본 논문에서는 미지의 공간에서 효과적으로 장애물을 회피할 수 있는 SFLC(single-input fuzzy logic controller) 기반의 이동로봇의 주행 제어기 설계와 구현을 제안한다. 장애물의 위치와 거리 인식을 위해 초음파센서를 사용하였으며, 좌, 우측 바퀴의 각속도 출력 제어를 위하여 퍼지논리시스템 기반의 제어기를 설계하였다. 퍼지제어기의 퍼지화 방법은 싱글톤 방법, 추론법은 간략화된 Mamdani의 추론법, 비퍼지화 방법은 간략화된 무게중심법을 사용하였다. 제안한 퍼지제어기의 성능 및 실제 적용 가능성의 평가를 위해 이동로봇의 모델링에 근거한 컴퓨터 시뮬레이션을 수행하였다. 그 결과 이동로봇이 장애물을 피하면서 목표지점에 정확히 도착함을 확인하였다. 더욱이 기존의 2-입력 퍼지논리시스템 기반의 제어기로부터 단일 입력을 가지는 단순구조 퍼지논리제어기를 설계할 수 있음도 보였다.

분산모듈형 태양광 전력조절기의 독립운전 제어 (Control Method of Distributed-Module Type Photovoltaic Power Conditioners under Stand-alone Operation)

  • 서정원;박종후;김혜림
    • 전력전자학회논문지
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    • 제18권5호
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    • pp.448-457
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    • 2013
  • This paper proposes a control method under stand-alone operating mode for distributed-module type photovoltaic power conditioners. In conventional schemes, there are some problems of a controller saturation in the DC-link (or load) voltage controller when overly-heavy load, light load, and the generated PV power reduction occurs, as well as when a transition occurs from an overly-loaded to normal conditions. To overcome these problems, the proposed controller method switches the main control target from DC-link voltage to the maximum power point, which is closer to the stable operating point when it returns to normal operating conditions. For the analysis, a state-plane trajectory was given and the circuit analysis by PSIM simulation was done. For the verification, a prototype hardware with 110[W] and 50[W] dual photovoltaic modules has been implemented. From the results, it can be seen that PV power tracking is successfully done with the proposed method even under a stand-alone operation mode.

차량 실내공간의 가속 시 엔진음 음질 향상을 위한 실시간 능동음향증강 제어 구현 (Implementation of Active Sound Enrichment Control for Improving Engine Sound Quality Inside the Cabin of a Passenger Car)

  • 이영섭;김제관;유석훈;김성현;박동철
    • 한국소음진동공학회논문집
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    • 제26권2호
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    • pp.195-202
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    • 2016
  • In this study, a concept of active sound enrichment (ASE) control system was implemented and demonstrated for improving engine sound quality inside the cabin of a passenger car during acceleration. Unlike the active noise control cancels the noise for disturbance rejection, the ASE adds additional sound to the noise for tracking control. This approach requires a new algorithm to provide additional artificial sound to the original engine sound using active control strategy to achieve a target sound profile, which is predefined to satisfy required interior sound quality. The ASE algorithm was implemented in a digital controller dSPACE DS1401 and real-time control experiment was accomplished in an actual car. The ASE control results show that the actively enriched sound of each engine order against RPM tracks the target profiles precisely and quickly and improves the discontinuity, the level ratios and the sound pressure level of each engine order. Thus it is anticipated the ASE system can be applied for the improvement of the engine sound quality inside the cabin during acceleration.

선박 자동접안시스템 구축을 위한 기초연구 (A Study on the Development of Automatic Ship Berthing System)

  • 김영복;최용운;채규훈
    • 동력기계공학회지
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    • 제10권4호
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    • pp.139-146
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    • 2006
  • In this paper vector code correlation(VCC) method and an algorithm to promote the image processing performance in building an effective measurement system using cameras are described for automatically berthing and controlling the ship equipped with side thrusters. In order to realize automatic ship berthing, it is indispensable that the berthing assistant system on the ship should continuously trace a target in the berth to measure the distance to the target and the ship attitude, such that we can make the ship move to the specified location. The considered system is made up of 4 apparatuses compounded from a CCD camera, a camera direction controller, a popular PC with a built in image processing board and a signal conversion unit connected to parallel port of the PC. The object of this paper is to reduce the image processing time so that the berthing system is able to ensure the safety schedule against risks during approaching to the berth. It could be achieved by composing the vector code image to utilize the gradient of an approximated plane found with the brightness of pixels forming a certain region in an image and verifying the effectiveness on a commonly used PC. From experimental results, it is clear that the proposed method can be applied to the measurement system for automatic ship berthing and has the image processing time of fourfold as compared with the typical template matching method.

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반복 학습 제어를 이용한 NFR 디스크 드라이브의 2단 서보 시스템 (A Dual-Stage Servo System for an NFR Disk Drive using Iterative Learning Control)

  • 문정호;도태용
    • 제어로봇시스템학회논문지
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    • 제9권4호
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    • pp.277-283
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    • 2003
  • Recently, near-field recording (NFR) disk drive schemes have been proposed with a view to increasing recording densities of hard disk drives. Compared with hard disk drives. NFR disk drives have narrower track pitches and are exposed to more severe periodic disturbances resulting from eccentric rotation of the disk. It is difficult to meet servo system design specifications for NFR disk drives with conventional VCM actuators in that the servo system for an NFR disk drive generally requires a feater gain and higher bandwidth. To tackle the problem various dual-stage actuator systems composed of a microactuator mounted on top of a conventional VCM actuator have been proposed. This article deals with the problem of designing a tracking servo system far an NFR disk drive adopting a dual-stage actuator. We summarize design constraints pertaining to the dual-stage servo system and present a new servo scheme using iterative teaming control. We design feedback compensators and an iterative teaming controller for a target plant and verify the validity of the proposed control scheme through a computer simulation.

조이스틱 명령에 따른 Electro-Optical Targeting Pod의 LOS 이동 알고리즘 설계 (LOS Moving Algorithm Design of Electro-Optical Targeting Pod for Joystick Command)

  • 서형규;박재영;안정훈
    • 전기학회논문지
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    • 제67권10호
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    • pp.1395-1400
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    • 2018
  • EO TGP(Electro-Optical Targeting Pod) is an optical tracking system which has various functions such as target tracking and image stabilization and LOS(Line of Sight) change. Especially, it is very important to move the LOS into a interest point for joystick command. When pilot move joystick in order to observe different scene, EO TGP gimbals should be operated properly. Generally, most EOTS just operate corresponding gimbal for joystick command. For example, if pilot input horizontal command in order to observe right hand screen, it just drive azimuth gimbal at any position. But in the screen, the image dosen't move in a horizontal direction because gimbal structure is Euler angle. And image rotation is occurred by elevation gimbal angle. So we need to move Pitch gimbal. So in the paper, we designed LOS moving algorithm which convert LOS command to gimbal velocity command to move LOS properly. We modeled a differential kinematic equation and then change the joystick command into velocity command of gimbals. This algorithm generate velocity command of each gimbal for same horizontal direction command. Finally, we verified performance through MATLAB/Simulink.

격자형 용접선 추적을 위한 용접 이동로봇의 모델링 및 제어 (Modeling and Control of Welding Mobile Robot for the Tracking of Lattice Type Welding Seam)

  • 이근유;서진호;오명석;김상봉
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.923-928
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    • 2003
  • This paper presents the motion control of a mobile robot with arc sensor for lattice type welding. Its dynamic equation and motion control method for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven along a straight line or comer. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider controls. For the torch slider control, the proportional integral derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the comer with range of $90^{\circ}$ constrained to the welding speed. The proposed control methods are proved through simulation results and the results have proved that the mobile robot has enough ability to apply the lattice type welding line.

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