• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.203-206
• /
• 1997

DC servo motors are widely used in many industrial fields as actuator of robot and driving power motors of electrical vehicle. Usually in the speed control systems, of motors, speed sensors are required and this fact results in the increased price and operating cost and the limited application of the motors. In this paper, a new speed control method for DC servo motor is proposed. In the scheme, the rotational speed is estimated by the measurement values of the armature voltage and current, instead of measurement by sensor. Optimal control theory is applied to design of the controller in construction of real system. This paper also report on the results of experiments to prove the validity of the proposed method.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.2
• /
• pp.87-94
• /
• 2015

This paper proposes a situation awareness method based on data fusion and independent objects for autonomous driving in on-road environment. The proposed method, designed to achieve an accurate analysis of driving situations in on-road environment, executes preprocessing tasks that include coordinate transformations, data filtering, and data fusion and independent object based situation assessment to evaluate the collision risks of driving situations and calculate a desired velocity. The method was implemented in an open-source robot operating system called ROS and tested on a closed road with other vehicles. It performed successfully in several scenarios similar to a real road environment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.6
• /
• pp.1365-1376
• /
• 1997

In this paper, we designed real time mechanism control language and proposed execution time analysis technique. It was impossible to handle real-time mechanism control programs like programmable controller, numerical controller, distributed control system and robot controller with general purpose programming languages and operating systems because they have to process electric signals generated by thousands of sensors at the same at the same time and in real time. So we made it possible to predict plausibility of time constraint constructs of tiem constraint construct of a real time application program at compilation time by adding time constraint constructs and mechanism synchronization structure to conditional statement and iteration statement of a programming language and developing execution time analysis technique.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.11a
• /
• pp.961-964
• /
• 2017

드론의 대중화에 따른 사고위험의 증가로 안전한 조종 방법에 대한 연구의 필요성이 대두되었다. 따라서 조종자의 조종능력에 구애받지 않는 자율비행제어기술이 필요하게 되었고, 이를 보다 안정적으로 구현하기 위하여 자율주행 소프트웨어 플랫폼으로 주목받고 있는 Robot Operating System(ROS)를 사용하였다. ROS를 기반으로 Laser Range Finder(LRF)와 Particle Filter를 사용하여 자율적으로 객체추적이 가능하며 지능적으로 장애물을 회피하여 비행 할 수 있는 안정적인 자율비행제어시스템을 구현하고자 한다.

• IE interfaces
• /
• v.6 no.2
• /
• pp.53-65
• /
• 1993

This paper deals with the development of a software module for production planning and scheduling activities of an existing Flexible Machining and Assembly System (FMAS). The Production Planning Module uses the hierarchical and sequential scheme based on "divide and conquer" philosophy. In this module, routes are determined based on the production order, orders are screened, tools are allocated, and order adjustments are executed according to the allocated tools. The Scheduling Module allocates the resources, determines the task priority and the start and completion times of tasks. Re-scheduling can be done to handle unforeseen situations such as lumpy demands and machine breakdowns. Since all modules are integrated with a central database and they interface independently, it is easy to append new modules or update the existing modules. The result of this study is used for operating the real FMAS consisting of a machining cell with 2 domestic NC machines and a part feeding robot, an assembly cell with a conveyor and 3 robots, an inspection cell, an AGV, an AS/RS, and a central control computer.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.400-403
• /
• 2005

The sonar sensors can be divided into a piezo type and an electrostatic type according to a principle of an operating system. The electrostatic type of a sonar sensor is used for map building in this paper. If we know the characteristics of sonar sensor, we can derive the ultrasonic pressure equation from an acoustics theory. We, therefore, developed Ultrasonic Pressure Probabilistic Model (UPPM) to consider the sound pressure in the probability updating process. In this paper, we found that the quality of the resulting probability map is considerably improved, through combining the UPPM with the grid-based mapping algorithm.

• Journal of Auto-vehicle Safety Association
• /
• v.13 no.4
• /
• pp.123-128
• /
• 2021

This paper present box feature estimation from LiDAR point cluster using maximum likelihood Method. Previous LiDAR tracking method for autonomous driving shows high accuracy about velocity and heading of point cluster. However, Assuming the average position of a point cluster as the vehicle position has a lower accuracy than ground truth. Therefore, the box feature estimation algorithm to improve position accuracy of autonomous driving perception consists of two procedures. Firstly, proposed algorithm calculates vehicle candidate position based on relative position of point cluster. Secondly, to reflect the features of the point cluster in estimation, the likelihood of the particle scattered around the candidate position is used. The proposed estimation method has been implemented in robot operating system (ROS) environment, and investigated via simulation and actual vehicle test. The test result show that proposed cluster position estimation enhances perception and path planning performance in autonomous driving.

• Review of KIISC
• /
• v.33 no.4
• /
• pp.57-63
• /
• 2023

Industry 4.0의 진행으로 이기종의 IoT 장비들 간의 통신을 위해 다양한 산업용 통신 미들웨어들이 등장했다. 그 중 Robotics 분야에서 활발히 사용되는 Robot Operating System (ROS)는 개발자 커뮤니티와 로봇 개발 도구들을 기반으로 지속적인 시장 점유율 증가세를 보이고 있다. 초기 발표된 ROS1의 경우 보안이 전혀 고려되지 않은 설계로 Packet Injection 공격등의 사이버 보안 위협에 취약했지만, ROS2의 경우 통신 미들웨어인 Data Distribution Service (DDS) 통신규격을 전송 계층에 적용하여 메시지 전송에 대한 보안 기능을 제공하고 있다. 그러나 최근 연구에서는 DDS와 관련된 ROS2 취약점이 발표되고 있다. 따라서 본 논문에서는 DDS와 관련된 ROS2의 공격 기술 동향을 소개한다.

• Journal of Auto-vehicle Safety Association
• /
• v.14 no.1
• /
• pp.20-25
• /
• 2022

This paper presents a development of simulation environment for validation of autonomous driving (AD) algorithm based on Robot Operating System (ROS). ROS is one of the commonly-used frameworks utilized to control autonomous vehicles. For the evaluation of AD algorithm, a 3D autonomous driving simulator has been developed based on LGSVL. Two additional sensors are implemented in the simulation vehicle. First, Lidar sensor is mounted on the ego vehicle for real-time driving environment perception. Second, GPS sensor is equipped to estimate ego vehicle's position. With the vehicle sensor configuration in the simulation, the AD algorithm can predict the local environment and determine control commands with motion planning. The simulation environment has been evaluated with lane changing and keeping scenarios. The simulation results show that the proposed 3D simulator can successfully imitate the operation of a real-world vehicle.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2020.07a
• /
• pp.335-338
• /
• 2020

주로 맵 빌딩 테스트는 불안정한 환경이 아닌 안정된 환경을 조성한 후에 이루어진다. 본 논문에서는 인위적인 안정된 환경이 아닌 불안정한 환경에서 맵 빌딩을 테스트한다. 맵 빌딩 테스트를 위하여 터틀봇3 버거를 사용한다. 터틀봇3의 라이더 센서를 이용하여 맵 빌딩을 진행한다. 터틀봇3는 라즈베리파이로 제어되며 맵 빌딩과 터틀봇3 제어를 위해서는 ROS를 사용한다. 터틀봇3는 우분투와 ROS가 설치된 컴퓨터와 네트워크 통신을 하며 맵 빌딩을 한다. 불안정한 환경에서 맵빌딩이 동작 및 오동작하는 모습을 확인하였으며, 향후 이를 보완하기 위한 방향을 제시한다.