• 자동차안전학회지
• /
• 제14권4호
• /
• pp.106-112
• /
• 2022

The purpose of this study is to explore ways of improving the motor vehicles safety certification system in preparation for the deployment of Lv.4 or higher autonomous vehicles. In order to effectively achieve the objectives of this study, theoretical and empirical research methodologies were employed, including literature review of prior research, government-published data, etc.; comparative research on legislative cases of other countries regarding motor vehicles safety certification; historical and legal research on domestic systems; legal analysis to explore approaches for improvement, etc. Some argue that the type approval system is needed in preparation for deploying autonomous vehicles, but there are several limitations in moving to the type approval system from the self-certification system currently adopted in Korea. First, there is a possibility that the system may be in conflict with the Korea-U.S. MOU regarding Foreign Motor Vehicles (1988) and the Korea-U.S. FTA (2011); second, there is a risk of undermining the cause of the self-certification system, which is the autonomy of manufacturers; third, the boundary between autonomous vehicles and non-autonomous vehicles is unclear; and fourth, the type approval system may hinder technological competitiveness. On the other hand, considering that the Korea-U.S. FTA and the UNECE IWVTA recognize exceptions to deal with road safety and risks to human health or the environment, and have a pre-certification system for some auto parts such as pressure-resistant containers, it can be said that there is room to introduce the type approval system for supplementation purposes. To improve the motor vehicles safety certification system while ensuring the safety of autonomous vehicles of Lv.4 or higher, the targets of type approval should be defined and the criteria, procedures, etc. for type approval should be established. At the same time, the consistency between motor vehicle-related laws and harmonization with international standards need to be considered.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제5권4호
• /
• pp.243-248
• /
• 2005

The UAV (Unmanned Aerial Vehicle) systems like unmanned autonomous helicopters are used in various missions of flight navigation and used to collect the environmental information of the surroundings. To realize the full functionalities of the UAV, the software part becomes a challenging problem. In this paper embedded real-time software architecture for unmanned autonomous helicopter is proposed that guarantee real-time performance of hard-real time tasks and re-configurability of soft-real time and non-real time tasks. The proposed software architecture has four layers: hardware, execution, service agent and remote user interface layer according to the reactiveness level for external events. In addition, the layered separation of concurrent tasks makes different kinds of mission reconfiguration possible in the system. An Unmanned autonomous helicopter system was implemented (Kyosho RC Helicopter) in our lab to test and evaluate the performance of the proposed system.

• International Journal of Ocean System Engineering
• /
• 제1권3호
• /
• pp.120-135
• /
• 2011

This paper proposes a model based trajectory tracking control scheme for under-actuated underwater robotic vehicles. The difficulty in stabilizing a non-linear system using smooth static state feedback law means that the design of a feedback controller for an under-actuated system is somewhat challenging. A necessary condition for the asymptotic stability of an under-actuated vehicle about a single equilibrium is that its gravitational field has nonzero elements corresponding to non-actuated dynamics. To overcome this condition, we propose a continuous time-varying control law based on the direct estimation of vehicle dynamic variables such as inertia, damping and Coriolis & centripetal terms. This can work satisfactorily under commonly encountered uncertainties such as an ocean current and parameter variations. The proposed control law cancels the non-linearities in the vehicle dynamics by introducing non-linear elements in the input side. Knowledge of the bounds on uncertain terms is not required and it is conceptually simple and easy to implement. The controller parameter values are designed using the Taguchi robust design approach and the control law is verified analytically to be robust under uncertainties, including external disturbances and current. A comparison of the controller performance with that of a linear proportional-integral-derivative (PID) controller and sliding mode controller are also provided.

• 대한수학회지
• /
• 제56권6호
• /
• pp.1561-1597
• /
• 2019

In this paper we introduce the notions of topological entropy and topological pressure for non-autonomous iterated function systems (or NAIFSs for short) on countably infinite alphabets. NAIFSs differ from the usual (autonomous) iterated function systems, they are given [32] by a sequence of collections of continuous maps on a compact topological space, where maps are allowed to vary between iterations. Several basic properties of topological pressure and topological entropy of NAIFSs are provided. Especially, we generalize the classical Bowen's result to NAIFSs ensures that the topological entropy is concentrated on the set of nonwandering points. Then, we define the notion of specification property, under which, the NAIFSs have positive topological entropy and all points are entropy points. In particular, each NAIFS with the specification property is topologically chaotic. Additionally, the ${\ast}$-expansive property for NAIFSs is introduced. We will prove that the topological pressure of any continuous potential can be computed as a limit at a definite size scale whenever the NAIFS satisfies the ${\ast}$-expansive property. Finally, we study the NAIFSs induced by expanding maps. We prove that these NAIFSs having the specification and ${\ast}$-expansive properties.

• Journal of Power Electronics
• /
• 제9권3호
• /
• pp.507-515
• /
• 2009

This paper proposes an autonomous decentralized control for a parallel connected uninterruptible power supply (UPS) system based on a fast power detection method using a FPGA based hardware controller for a single phase system. Each UPS unit detects only its output voltage and current without communications signal exchange and a quasi dq transformation method is applied to detect the phase and amplitude of the output voltage and the output current for the single phase system. Fast power detection can be achieved based on a quasi dq transformation, which results in a realization of very fast transient response under rapid load change. In the proposed method, the entire control system is implemented in one FPGA chip. Complicated calculations are assigned to hardware calculation logic, and the parallel processing circuit makes it possible to realize minimized calculation time. Also, an Nios II CPU core is implemented in the same FPGA chip, and the software can be applied for non-time critical calculations. Applying this control system, an autonomous decentralized UPS system with very fast transient response is realized. Feasibility and stable operation are confirmed by means of an experimental setup with three UPSs connected in parallel. Also, rapid load change is applied and excellent performance of the system is confirmed in terms of transient response and stability.

• 제어로봇시스템학회논문지
• /
• 제13권8호
• /
• pp.726-734
• /
• 2007

Generally, a mobile robot is moved by original input programs. However, it is very hard for a non-expert to change the program generating the moving path of a mobile robot, because he doesn't know almost the teaching command and operating method for driving the robot. Therefore, the teaching method with speech command for a handicapped person without hands or a non-expert without an expert knowledge to generate the path is required gradually. In this study, for easily teaching the moving path of the autonomous mobile robot, the autonomous mobile robot with the function of speech recognition is developed. The use of human voice as the teaching method provides more convenient user-interface for mobile robot. To implement the teaching function, the designed robot system is composed of three separated control modules, which are speech preprocessing module, DC servo motor control module, and main control module. In this study, we design and implement a speaker dependent isolated word recognition system for creating moving path of an autonomous mobile robot in the unknown environment. The system uses word-level Hidden Markov Models(HMM) for designated command vocabularies to control a mobile robot, and it has postprocessing by neural network according to the condition based on confidence score. As the spectral analysis method, we use a filter-bank analysis model to extract of features of the voice. The proposed word recognition system is tested using 33 Korean words for control of the mobile robot navigation, and we also evaluate the performance of navigation of a mobile robot using only voice command.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
• /
• pp.834-837
• /
• 1993

This paper describes the implementation of an autonomous fuzzy logic controller. The controller is endowed with basic control principles and learning constructs which enable it to autonomously modify its control policy based on system performance. The controller lies dormant when system response is satisfactory but if rapidly initiates adaptation in real time when adverse performance is observed. The autonomous fuzzy controller is implemented on an Intel MCS-51 series micro-controller board using an inexpensive 8-bit Intel 8031 processor. The 11.06 MHz micro-controller operates at a rate exceeding 200 "global" look-up table reinforcements per second. This is important when developing practical on-line adaptive controllers for fast systems. It is also significant because an initial controller look-up table could be incorrect or non-existent. The relatively high learning rate enables the controller to learn to control a system even while it is controlling it.

• 한국ITS학회 논문지
• /
• 제21권4호
• /
• pp.167-189
• /
• 2022

SAE 기준 자율주행 레벨 2, 3의 경우 완전 자율주행이 불가능하므로 주행에 있어 제어권 전환 과정이 필수적이며, 제어권 전환 소요시간은 자율주행시스템의 안전성을 결정하는 가장 중요한 요소이다. 이에 따라 제어권 전환 소요시간에 대한 연구가 활발히 진행되고 있으나, 각 연구는 독립적으로 시행되어 다양한 연구 결과를 통합한 일반적인 결론 도출이 필요한 실정이다. 따라서, 본 연구는 개별 연구 결과를 통합해서 통합적인 의견을 제시하는 메타분석 기법을 사용하여 제어권 전환 소요시간에 영향을 주는 요인을 분석하였다. 메타분석 결과, 총 10개의 영향요인이 선정되었으며 대부분이 비운전 업무 유형과 관련되어 있었다. 또한, 향후 제어권 전환 및 비운전 업무 연구 수행 방향성 측면에서 시사점을 제시하였다.

• 대한기계학회논문집
• /
• 제18권8호
• /
• pp.2062-2072
• /
• 1994

This paper presents the development of a fuzzy controller for driving camera pan/tilt device so that the camera's viewing direction can automatically track a moving object. To achieve computational efficiency a non-contact type displacement follower is used as a feedback sensor instead of a vision camera. The displacement follower, however, is extremely sensitive to object's lighting condition and results in unstable response at high speed. To this end, a fuzzy controller is developed in such a way to provide stable tracking performance at high speed where the sensory signal is subjected to intermittant disturbances of large magnitude. The test result shows stable tracking response even for high speed and non-uniform lighting condition. The resulting camera autotracking system can be adopted as an effective tool for visual transfer in the context of teleoperation and autonomous robotics.

• 한국ITS학회 논문지
• /
• 제19권6호
• /
• pp.222-234
• /
• 2020

자율주행차는 GPS 및 레이더, 라이다, 카메라, IMU 등 다수의 센서가 장착되어 도심 교차로 주행 환경에서 다양한 교통체계를 인지하고 판단하여 주행하지만 장착된 센서의 감지 거리를 벗어나는 영역에 대한 예측 및 판단의 한계 등으로 자율주행차의 교차로 사고 비율은 전체 사고의 88%로 사고 비율이 높다. 따라서 ITS 도입으로 V2V, V2I를 통한 비신호 교차로 사고 회피 전략 연구가 진행되고 있을 뿐만 아니라 고장 상황에서 안전한 교차로 주행에 대한 연구도 진행되고 있지만 단순한 교차로 시나리오를 통한 검증과 단편적인 V2V 고장만을 제시하고 있다. 본 논문에서는 V2V 모듈의 아키텍쳐를 분석하여 V2V 모듈별 위험 요인을 분석하여 고장모드를 정의하였다. 또한 다양한 도로 조건 및 교통량에 따라 교차로 시나리오를 제시하여 ISO-26262 Part3 프로세스를 활용하여 HARA를 수행하여 자율주행차의 오작동에 대해 시뮬레이션 기반 위험성을 분석하여 ASIL을 제시하였다. V2V 모듈의 각 컴포넌트별 모니터링 컨셉을 제안하였고 시뮬레이션을 통해 모니터링 커버리지를 제시하였다.