• 전기학회논문지
• /
• 제63권1호
• /
• pp.92-98
• /
• 2014

This paper proposes a hermite spline based D* algorithm for effective path planning of mobile robot to improve the detecting speed. In conventional path planning research, a robot is supposed to pass through predetermined centers of grid partitions of area. However it doesn't guarantee the optimal path during its navigation. In addition, a robot is hard to avoid obstacles effectively. The proposed algorithm in this paper makes use of stochastic characteristics of nonholonomic mobile robot and estimation of shortest path to curvature movement of the robot. The performance evaluation of the improved spline D* algorithm performed through simulation shows its effectiveness. Moreover, the experiment verifies that a robot can find the shortest path by building the curve paths while it is moving on the path in spline.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1797-1801
• /
• 2005

SLAM(Simultaneous localization and mapping) and AI(Artificial intelligence) have been active research areas in robotics for two decades. In particular, localization is one of the most important issues in mobile robot research. Until now expensive sensors like a laser sensor have been used for the mobile robot's localization. Currently, as the RFID reader devices like antennas and RFID tags become increasingly smaller and cheaper, the proliferation of RFID technology is advancing rapidly. So, in this paper, the smart floor using passive RFID tags is proposed and, passive RFID tags are mainly used to identify the mobile robot's location on the smart floor. We discuss a number of challenges related to this approach, such as RFID tag distribution (density and structure), typing and clustering. In the smart floor using RFID tags, because the reader just can senses whether a RFID tag is in its sensing area, the localization error occurs as much as the sensing area of the RFID reader. And, until now, there is no study to estimate the pose of mobile robot using RFID tags. So, in this paper, two algorithms are suggested to. We use the Markov localization algorithm to reduce the location(X,Y) error and the Kalman Filter algorithm to estimate the pose(q) of a mobile robot. We applied these algorithms in our experiment with our personal robot CMR-P3. And we show the possibility of our probability approach using the cheap sensors like odometers and RFID tags for the mobile robot's localization on the smart floor.

• 한국생산제조학회지
• /
• 제23권4호
• /
• pp.374-379
• /
• 2014

Mobile robots with omni-directional wheels can generate instant omni-directional motion without requiring extra space to change the direction of the body. Therefore, they are capable of moving in an arbitrary direction under any orientation even in narrow aisles or tight areas. In this research, an omni-directional mobile robot based on Mecanum wheels was developed to achieve omni-directionality. A CompactRIO embedded real-time controller and C series motion and I/O modules were employed in the control system design. Ultrasonic sensors installed on the front and lateral sides were utilized to measure the distance between the mobile robot and the side wall of a workspace. Through intensive experiments, a performance evaluation of the mobile robot was conducted to confirm its feasibility for industrial purposes. Mobility, omni-directionality, climbing capacity, and tracking performance of a squared trajectory were selected as performance indices to assess the omni-directional mobile robot.

• 로봇학회논문지
• /
• 제17권2호
• /
• pp.124-132
• /
• 2022

With growth in intelligence of mobile robots, interaction with humans is emerging as a very important issue for mobile robots and the pedestrian tracking technique following the designated person is adopted in many cases in a way that interacts with humans. Among the existing multi-object tracking techniques for pedestrian tracking, Simple Online and Realtime Tracking (SORT) is suitable for small mobile robots that require real-time processing while having limited computational performance. However, SORT fails to reflect changes in object detection values caused by the movement of the mobile robot, resulting in poor tracking performance. In order to solve this performance degradation, this paper proposes a more stable pedestrian tracking algorithm by correcting object tracking errors caused by robot movement in real time using wheel odometry information of a mobile robot and dynamically managing the survival period of the tracker that tracks the object. In addition, the experimental results show that the proposed methodology using data collected from actual mobile robots maintains real-time and has improved tracking accuracy with resistance to the movement of the mobile robot.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2002년도 춘계학술대회 및 임시총회
• /
• pp.105-108
• /
• 2002

This paper represents the mobile robot control system remote controlled by PDA(personal digital assistance). So far, owing to the development of internet technologies, lots of remote control methods through internet have been proposed. To control a mobile robot through internet and guide it under unknown environment, We propose a control method activated by PDA. In a proposed system, PDA acts as a user interface to communicate with notebook as a controller of the mobile robot system using TCP/IP protocol, and the notebook controls the mobile robot system. The information about the direction and velocity of the mobile robot feedbacks to the PDA and the PDA send new control method produced from the fuzzy inference engine.

• 로봇학회논문지
• /
• 제17권2호
• /
• pp.183-190
• /
• 2022

Accurate kinematic parameters of mobile robots are essential because inaccurate kinematic model produces considerable uncertainties on its odometry and control. Especially, kinematic parameters of caster type mobile robots are important due to their complex kinematic model. Despite the importance of accurate kinematic parameters for caster type mobile robots, few research dealt with the calibration of the kinematic model. Previous study proposed a calibration method that can only calibrate double-wheeled caster type mobile robot and requires direct-measuring of robot center point and distance between casters. This paper proposes a calibration method based on geometric approach that can calibrate single-wheeled caster type mobile robot with two or more casters, does not require direct-measuring, and can successfully acquire all kinematic parameters required for control and odometry. Simulation and hardware experiments conducted in this paper validates the proposed calibration method and shows its performance.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.21-24
• /
• 2004

This paper describes a perception of small-obstacle using ultrasonic sensors in a mobile robot. The research on the avoidance of the large-obstacles such as a wall, a large box, etc. using ultrasonic sensors has been generally progressed up to now. But the mobile robot could meet a small-obstacle such as a small plastic bottle of about 1 l in quantity, a small box of 7${\times}$7${\times}$7 cm3 in volume, and so on in its designated path, and could be disturbed by them in the locomotion of the mobile robot. So, it is necessary to research on the avoidance of a small-obstacle. In this paper, the small-obstacle perceiving system was designed and fabricated by arranging four ultrasonic sensors on the plastic plate to avoid a small-obstacle. The small-obstacle perceiving system was installed on the above part of the mobile robot with the slope of 40.7$^{\circ}$ to a horizontal line. The static characteristic test and the dynamic characteristic test were performed to know the information of the used ultrasonic sensors. As a result, the mobile robot with the small-obstacle perceiving system could avoid a small-obstacle, and could move in indoor environment safely.

• 한국정보통신학회논문지
• /
• 제4권3호
• /
• pp.585-594
• /
• 2000

생산현장이나 불확실한 환경에서 자율이동로봇의 정확한 경로 추종은 고전적 제어 알고리즘인 경우에 많은 단점을 갖고 있다. 본 논문에서는 오류 역전파 알고리즘을 기반으로 한 신경망을 이용하여 이동로봇이 바닥 위에 설치된 선을 따라갈 수 있도록 하였다. 로봇에 부착된 3 개의 센서들로부터 인식된 정보뿐만 아니라 센서들이 인식하지 못하는 영역에서도 10등분된 세밀한 정보가 입력패턴으로 학습되기 때문에 센서들이 인식하지 못하는 영역에서도 이동로봇은 라인을 따라 원활하게 이동한다. 로봇이 목적지까지 이동하는데 걸리는 시간이 단축되고 라인과의 오차를 최소화하는 효과를 가져온다. 제안된 신경회로망 제어기의 효과를 검증하기 위하여 이동로봇의 이동 각의 변화에 따른 두개의 모터의 속도 변화가 컴퓨터로 시뮬레이션 된다.

• 한국산학기술학회논문지
• /
• 제9권1호
• /
• pp.64-69
• /
• 2008

이동로봇이 임의의 작업공간에서 임무를 수행하기 위해서는 주변 환경에 대한 위치 인식 능력이 있어야 한다. 본 논문에서는 새로운 능동형 인공표지를 이용하여 이동로봇의 위치를 인식할 수 있는 방법을 제안한다. 능동형 인공표지에는 이동로봇에서 무선통신으로 제어가 가능한 LED가 부착되어 있는데, 제안한 방법은 CCD 카메라로 인공표지의 LED가 점등 및 소등된 두 영상의 차영상을 이용하여 인공표지 여부를 판별하기 때문에 주변 환경의 복잡도에 관계없이 인식시간을 최소화할 수 있으며 인공표지의 특징점 정보를 이용하여 간단하게 위치를 인식할 수 있다. 제안한 방법의 성능을 평가하기 위하여 실험을 하였으며 실험 결과는 제안한 방법이 이동로봇의 위치 인식에 적용될 수 있음을 보였다.

• Journal of information and communication convergence engineering
• /
• 제10권4호
• /
• pp.372-377
• /
• 2012

In this paper, we propose an implementation of a real-time operating system for the two-wheel mobile robot. With this implementation, we have the ability to control the complex embedded systems of the two-wheel mobile robot. The advantage of the real-time operating system is increasing the reliability and stability of the two-wheel mobile robot when they work in critical environments such as military and industrial applications. The real-time operating system which was ported to this implementation is open systems and the corresponding interfaces for automotive electronics (OSEK/VDX). It is known as the set of specifications on automotive operating systems, published by a consortium founded by the automotive industry. The mechanical design and kinematics of the two-wheel mobile robot are described in this paper. The contributions of this paper suggest a method for adapting and porting OSEK/VDX real-time operating system to the two-wheel mobile robot with the differential drive method, and we are also able to apply the real-time operating system to any complex embedded system easily.