• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.311-312
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• 2006

In this paper, steering systems for mobile robot with permanent magnet wheels are discussed. The mobile robot with permanent magnet wheels can have three different types of steering and driving configurations; two-wheels, three-wheels, four-wheels. By a Two-WD(Wheel Driving) system, driving and steering characteristics are controlled by ratio of each wheel speeds. Three-WD system is steered by a front wheel and driven by rear wheels. Four-WD system has better stability than two wheel system. Usually the permanent magnet wheel has nearly none slip. Thus turning radius of the mobile robot with three-WD and four-WD System will be increased and the steering and driving system will be complicated. To solve this problem, two magnet wheels with two dummy wheels are used in this study. fuming radius of the developed mobile robot is small and the structure of the robot is simple. It is possible to move forward, backward, to turn left and right, and to rotate freely with two-WD. This study proved that two-WD system is very suitable fur the mobile robot with permanent magnet wheels.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.105.5-105
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• 2001

This paper describes a fuzzy steering controller for an autonomous mobile robot with MR sensor. Using the magnetic field(Bx, By, Bz) obtained from the MR sensor, we designed fuzzy controller for driving on the road center. Fuzzy rule base was built to magnetic field(Bx, By, Bz). To develop an autonomous mobile robot simulation program, we have done modeling MR sensor, dynamic model of mobile robot and coordinate transformation. A computer simulation of the robot including mobile robot dynamics and steering was used to verify the steering performance of the mobile robot controller using the fuzzy logic Good results were obtained by computer simulation. So, we confirmed the robustness of the proposed fuzzy controller by computer ...

• 대한임베디드공학회논문지
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• 제17권2호
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• pp.109-114
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• 2022

This paper proposes a 2D joystick and LoRa-based teleoperation system for the Ackermman steering mobile robot. The proposed joystick mapping algorithm reduces the linear speed of the robot when the joystick is steered in the direction of the maximum steering angle in the high-speed driving state of a mobile robot to reduce the risk of rollover. The LoRa-based remote operation system is designed for remote operation of mobile robots that require long range communication with relatively little data transmission and low power. The proposed system is implemented and the experimental results demonstrate the effectiveness of the teleoperation system with respect to the stability of communication strength and the robot motion.

• 한국위성정보통신학회논문지
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• 제11권4호
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• pp.39-43
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• 2016

본 논문은 조향구조를 갖는 이동로봇의 조향 제어를 위해 PID 제어기의 이득을 튜닝 방법을 제안한다. PID 이득을 설정하는 다양한 방법들이 제시되고 연구되고 있다. 이득은 지글러-니콜스의 계단형 입력으로부터 이득을 얻는 방법으로 얻어진 이득을 이동로봇에 적용하고 이를 시험하여 다시 2차 전달함수에 의해 새로운 이득을 계산하였다. 얻어진 새로운 이득으로 응답시간 및 유지오차율에 관한 실험을 수행하여 PID 자동 튜닝의 성능을 확인하였다. 유지시간, 응답시간 및 수렴시간에 대한 실험결과로 이동로봇의 조향 시스템에서 사용이 가능하고 응답 시간이 빠르게 도달할 수 있으며 안정하게 제어됨을 확인하였다.

• 한국지능시스템학회논문지
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• 제12권1호
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• pp.27-32
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• 2002

본 논문은 MR(magneto-resistive)센서를 이용한 실외형 자율 이동 로봇의 퍼지 조향 제어기에 대한 연구이다. 2개의 MR 센서를 이용한 지구자기장의 제거방법을 제안하고, 각각의 센서에서 측정된 자기장 차이값(dBy, dBz)을 입력변수로 사용한 퍼지 조향 제어기를 설계하였다. 자율 이동 로봇 시뮬레이션 프로그램을 개발하기 위해 MR센서의 모델링, 이동로봇의 동적모델링, 좌표변환 등을 하였다. 컴퓨터 시뮬레이션은 퍼지 로직을 이용한 이동로봇 제어기의 주행성능을 검증하기 위해 사용되었고 그 시뮬레이션을 통하여 제안한 퍼지 조향제어기의 강인성을 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.787-792
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• 1991

This paper proposes a steering control algorithm for non-holonomic mobile robots. The steering control algorithm is essential to navigate autonomous vehicles which employ comination of the dead reckoning and absolute sensor system such as a machine vison for detecting landmarks in order to estimate the current location of the mobile robot. The proposed algorithm is based on the minimum time BANG-BANG controller and curvature-continuity curve design method. In the BANG-BANG control scheme we introduce velocity/acceleration limiter to avoid any slippage of driving wheels. The proposed scheme is robot-independent and hence can be applied to various kinds of mobile robot or vehicles. To show the effectness of the proposed control algorithm, a series of computer simulations were conducted for two-wheel driven mobile robot.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2365-2368
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• 2001

This paper describes a fuzzy steering controller for an autonomous mobile robot with MR sensor. Using the magnetic field($B_{x}$, $B_{y}$, $B_{z}$) obtained from the MR sensor, we designed fuzzy controller for driving on the road center. Fuzzy rule base was built to magnetic field($B_{x}$, $B_{y}$, $B_{z}$). To develop an autonomous mobile robot simulation program, we have done modeling MR sensor, dynamic model of mobile robot and coordinate transformation. A computer simulation of the robot (including mobile robot dynamics and steering) was used to verify the steering performance of the mobile robot controller using the fuzzy logic. Good results were obtained by computer simulation. So, we confirmed the robustness of the proposed fuzzy controller by computer simulation. Also, we know that proposed control algorithm was applied to real autonomous mobile robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.37.6-37
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• 2002

Omnidirectional mobile robots are capable of arbitrary motion in an arbitrary direction without changing the direction of wheels, because they can perform 3 degree-of-freedom (DOF) motion on a 2-dimensional plane. In this research, a new class of an omnidirectional mobile robot is proposed. Since it has synchronously steerable omnidirectional wheels, it is called an omnidirectional mobile robot with steerable omnidirectional wheels (OMR-SOW). It has 3 DOFs in motion and one DOF in steering. One steering DOF can function as a continuously variable transmission (CVT). CVT of the OMR-SOW increases the range of velocity ratio from the wheel velocities to robot velocity, which may improve...

• 제어로봇시스템학회논문지
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• 제12권12호
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• pp.1235-1240
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• 2006

Previous isotropy analysis of a caster wheeled omnidirectional mobile robot(COMR) has been made under the assumption that the steering link offset is equal to the caster wheel radius. Nevertheless, many practical COMR's in use take advantage of the steering link offset different from the wheel radius, mainly because of improved stability. This paper presents the isotropy analysis of a fully actuated COMR with variable steering link offset, which can be considered as the generalization of the previous analysis. First, the kinematic model of a COMR under full actuation is obtained based on the orthogonal decomposition of the wheel velocities. Second, the necessary and sufficient conditions for the isotropy of a COMR are derived and examined to categorize three different groups, each of which can be dealt with in a similar way. Third, for each group, the isotropy conditions are further explored so as to identify all possible isotropic configurations completely.

• 대한임베디드공학회논문지
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• 제9권4호
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• pp.237-243
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• 2014

In this paper we present an real-time obstacle avoidance technique of autonomous mobile robot with steering system and implementation of user interface for mobile devices with Android platform. The direction of autonomous robot is determined by virtual force field concept, which is based on the distance information acquired from 5 ultrasonic sensors. It is converted to virtual repulsive force around the autonomous robot which is inversely proportional to the distance. The steering system with PD(proportional and derivative) controller moves the mobile robot to the determined target direction. We also use PSD(position sensitive detector) sensors to supplement ultrasonic sensors around dead angle area. The mobile robot communicates with Android mobile device and PC via Ethernet. The video information from CMOS camera mounted on the mobile robot is transmitted to Android mobile device and PC. And the user can control the mobile robot manually by transmitting commands on the user interface to it via Ethernet.