Earticle

In this paper, we design a basic algorithm enabling recognition of surrounding environment and collision avoidance among elemental technologies for autonomous driving, also applies sensor theoretical data and actual road performance to robo-racing system based on experimental data obtained through driving tests to enable sophisticated collision avoidance. For this study, a commercial autonomous driving patform(ERP-42), LiDAR and GPS sensors were used to implement efficient comunication systems and autonomous driving algorithms between each module.

A path planning using potential field method is very useful for the real-time navigation of mobile robots. However, the method needs high modeling cost to calculate the potential field because of complex preprocessing, and mobile robots may get stuck into local minima. In this paper, An efficient path planning algorithm for multiple mobile robots, based on the potential field method, was proposed. In the algorithm. the concepts of subgoals and obstacle priority were introduced. The subgoals can be used to escape local minima, or to design and change the paths of mobile robots in the work space. In obstacle priority, all the objects (obstacles and mobile robots) in the work space have their own priorities, and the object having lower priority should avoid the objects having higher priority than it has. In this paper, first, potential based path planning method was introduced, next an efficient collision-avoidance algorithm for multiple mobile robots, moving in the obstacle environment, was proposed by using subgoals and obstacle priority. Finally, the developed algorithm was demonstrated graphically to show the usefulness of the algorithm.

지상 무인 차량(UGV), 무인기(UAV), 무인수상정(USV), 무인잠수정(UUV), 로봇 등과 같은 다중 무인체가 대형을 이루면서 군집 주행을 할 때 충돌회피 문제는 다중 에이전트 시스템에서 기본적으로 구현해야 하는 것으로 중요하게 인식되었다. 다중무 인체들은 가까운 미래에 생화학 오염지역이나 위험한 전투지역에서의 신속하게 투입되어 주어진 임무를 수행할 것이다. 다중 무인체가 편대를 이루어 출발지점에서 목표점인 임무 지역으로 이동할 때 자율주행을 할 수 있는 선도-추종 대형제 어를 적용하고, 다중무인체가 군집 자율주행할 때 갑자기 동적장애물 등이 나타나거나 주행 경로상에 고정장애물이 존재할 경우 이를 회피하기 위해 인공전위장을 이용한다. 지상전에서 다중 무인체의 장애물 회피 시스템에 대한 대형제어 알고리즘 성능을 평가하기 위해, 다중 무인체가 각각 3대, 5대, 7대, 그리고 장애물이 각각 0개, 1개, 3개, 5개인 경우에 대해 이들을 조합한 여러 가지 군집 자율주행상황을 시뮬레이션하였다.

It has been importantly recognized that the collision avoidance problem of multiple unmanned vehicles(MUVs) such as UGV, UAV, USV, UUV, Robot, etc. for platoon autonomous navigation in dynamic environments should be implemented basically in multiple agent systems. In the near future, they will be dispatched quickly and carry out their assigned tasks in biochemical contaminated area or dangerous combant areas. When multiple unmanned vehicles form a platoon formation and move from the starting point to the target point, leader-follower formation control that can autonomously navigate is applied. When multiple unmanned vehicles are autonomously driving in clusters, if a dynamic obstacle suddenly appears or there is a fixed obstacle on the driving path, artificial potential is used to avoid them. In order to check the performance of the formation control algorithm for the obstacle avoidance system of multiple unmanned vehicles in ground warfare, in the case of multiple unmanned vehicles with 3, 5, 7, and 0, 1, 3, and 5 obstacles, respectively, various platooning autonomous navigation situations were simulated by combining them.

본 논문은 자율주행 개인화를 위한 역 충돌시간 및 차두시간 융합 기반 인간중심 제어 알고리즘 개발에 관한 것이다. 운전자 및 탑승자의 자율주행에 대한 이질감 최소화를 위해 인간중심적 주행제어 기술이 필요하다. 운전자가 선행차량과 함께 주행하는 조건에서 운전자의 주행특성을 분석하고, 분석된 결과를 종방향 자율주행 제어에 반영하였다. 주행특성으로 가속도, 역 충돌시간, 차두시간 분포가 분석되었고, 운전자의 주행특성이 반영된 제어기 구성을 위해 역 충돌시간 및 차두시 간을 이용한 종방향 제어기를 구성하였다. 본 연구에서 제안된 제어 알고리즘은 Matlab/Simulink 환경에서 구성되었으며 실 주행데이터 기반 성능평가가 수행되었다.

This paper presents a human-centered control algorithm for personalized autonomous driving based on the integration of inverse time-to-collision and time headway. In order to minimize the sense of difference between driver and autonomous driving, the human-centered control technology is required. Driving characteristics in case that vehicle drives with the preceding vehicle have been analyzed and reflected to the longitudinal control algorithm. The driving characteristics such as acceleration, inverse time-to-collision, time headway have been analyzed for longitudinal control. The control algorithm proposed in this study has been constructed on Matlab/Simulink environment and the performance evaluation has been conducted by using actual driving data.

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

In swarm control research, the two most important issues are collision avoidance among moving objects and vehicle-to-vehicle communication (V2V communication). Leader-Follower method, the commonly used in swarm control, has problems about these two function. Data loss in communication or a failure of the leader can cause the entire formation to become uncontrollable. To resolve this problem, this paper suggests the variable Leader-Follower method and collision avoidance process based on the Velocity Obstacle method. Instead of fixing a leader, it selects the leader using an allocation algorithm based on the navigation situation. Also, each ship except the leader, in the swarm choose new ideal point using formation matrix that contains the distance from each ship to ideal points. To avoid static and dynamic obstacles, each ships in the swarm make local path using Velocity Obstacle method(VO) with Quadrangle Ship Domain (QSD). If there is no collision risk, they follow the global path; Otherwise, they plans the local path that can avoid collisions with other vessels and obstacles. To validate the algorithm proposed in this paper, navigation simulations are conducted in the simulation environment based on a MMG type manoeuvring model. It is confirmed that the follower can maintain their formation by formation control and appropriate leader was selected based on the current situation by path following control. The collision avoidance simulation with static, dynamic and complex obstacles ensured that the vessels in the swarm can avoid the collision and they can find the optimum formation.

In swarm control research, the two most important issues are collision avoidance among moving objects and vehicle-to-vehicle communication (V2V communication). Leader-Follower method, the commonly used in swarm control, has problems about these two function. Data loss in communication or a failure of the leader can cause the entire formation to become uncontrollable. To resolve this problem, this paper suggests the variable Leader-Follower method and collision avoidance process based on the Velocity Obstacle method. Instead of fixing a leader, it selects the leader using an allocation algorithm based on the navigation situation. Also, each ship except the leader, in the swarm choose new ideal point using formation matrix that contains the distance from each ship to ideal points. To avoid static and dynamic obstacles, each ships in the swarm make local path using Velocity Obstacle method(VO) with Quadrangle Ship Domain (QSD). If there is no collision risk, they follow the global path; Otherwise, they plans the local path that can avoid collisions with other vessels and obstacles. To validate the algorithm proposed in this paper, navigation simulations are conducted in the simulation environment based on a MMG type manoeuvring model. It is confirmed that the follower can maintain their formation by formation control and appropriate leader was selected based on the current situation by path following control. The collision avoidance simulation with static, dynamic and complex obstacles ensured that the vessels in the swarm can avoid the collision and they can find the optimum formation.

This paper describes design and tuning of a full-range Adaptive Cruise Control (ACC) with collision avoidance. The control scheme is designed to control the vehicle so that it would feel natural to the human driver and passengers during normal safe driving situations and to avoid rear-end collision in vehicle following situations. In this study, driving situations are determined using a non-dimensional warning index and time-to-collision (TTC). A confusion matrix method based on natural driving data sets was used to tune control parameters in the proposed ACC System. An ECU-Brake Hardware-in-the-loop Simulation (HiLS) was developed and used for an evaluation of ACC System. The ECU-Brake HiLS results for alternative driving situation are compared to manual driving data measured on actual traffic way. The ACC/CA control logic implemented in an ECU was tested using the ECU-Brake HiLS in a real vehicle environment.

Communication based train control system is applied regularly worldwide. And this system may be used in domestic soon. Communication based train control system does not depend on conventional track circuit. Therefore, position and distance control of train to prevent collision with leading train may become important safety factor. This paper developed collision avoidance algorithm to control trains of several units efficiently for this. In developing a collision avoidance algorithm, it is desirable to avoid the need for additional system. Additional system restricts the development of the algorithm by limiting the effectiveness of the algorithm to only those areas where the additional system can be afforded and has been installed.

Communication based train control system is applied regularly worldwide. And this system may be used in domestic soon. Communication based train control system does not depend on conventional track circuit. Therefore, position and distance control of train to prevent collision with leading train may become important safety factor. This paper developed collision avoidance algorithm to control trains of several units efficiently for this. In developing a collision avoidance algorithm, it is desirable to avoid the need for additional system. Additional system restricts the development of the algorithm by limiting the effectiveness of the algorithm to only those areas where the additional system can be afforded and has been installed.

A haptic device operated by the user's hand can receive information on position and orientation of the hand and display force and moment generated in the virtual environment to the hand. For realistic haptic display, the detailed information on collision between objects is necessary. In the past, the point-based graphic environment has been used in which the end effector of a haptic device was represented as a point and the interaction of this point with the virtual environment was investigated. In this paper, the shape-based graphic environment is proposed in which the interaction of the shape with the environment is considered to analyze collision or contact more accurately. To this end. the so-called Gilbert-Johnson-Keerthi (GJK) algorithm is adopted to compute collision points and collision instants between two shapes in the 3-D space. The 5- DOF haptic hand controller is used with the GJK algorithm to demonstrate a peg-in-hole operation in the virtual environment in conjunction with a haptic device. It is shown from various experiments that the shape-based representation with the GJK algorithm can provide more realistic haptic display for peg-in-hole operations.

본 논문에서는 완전 자동화된 개인고속이동 시스템의 원활한 차량운행 제어를 위한 운행속도 패턴과 차량간의 충돌을 방지하기 위한 알고리즘의 설계 및 설계된 알고리즘의 검증을 위한 하드웨어 구성에 대해서 다룬다.