• 전자공학회논문지B
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• 제33B권4호
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• pp.27-40
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• 1996

This paper proposed a kinematic modeling methodlogy and feedback control system based on kinematics for 2 degrees of freedom of 4-wheeled mobile robot. We assigned coordinate systems to specify the transformation matirx and write the kinematic equation of motion. We derived the actuated inverse and sensed forwared solution for the calculation of actual robot orientation and the desired robot orientation. It is the most significant error and has the largest impact on the motion accuracy. To calculate the WMR position in real time, we introduced the dead-reckoning algorithm and composed two feedback control system that is based on kinematics. Through the simulation result, we compare with the ffedback control system for position control.

• 한국정밀공학회지
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• 제16권9호
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• pp.159-165
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• 1999

Based on the cable-extension transducers, a new technique for two dimensional position measurement is developed in this paper. This new technique includes the use of two such transducers and the planar position is determined through triangulation. This paper also presents uncertainty analysis results for establishing sensor design specifications. An actual prototyped sensor system is built and its accuracy is verified through h\both experiments with coordinate measurement machines and its application to the real-time control of a high load wheeled mobile robot. This new type of position sensor can be easily used in a wide variety of automation applications in industry for two dimensional position measurements with high accuracy over a relatively large range, and it is both cast effective and robust against hostile environments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1172-1177
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• 2003

In this paper, we propose an obstacle avoidance technique in trajectory tracking of nonholonomic wheeled mobile robots. Input-output linearized backstepping controller is used in trajectory tracking, and repulsive type control input for obstacle avoidance is added to it. The added input is generated by fuzzy logic. And we do not add the two inputs directly but combine them via fuzzy logic, which determines the ratings of each input. Some simulations are performed to show that with the proposed algorithm, the mobile robot can track its reference trajectory even if there are multiple obstacles on the trajectory of robot.

• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1287-1296
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• 2014

This paper is about control of Automated Guided Vehicle for path following using fuzzy logic controller. The Automated Guided Vehicle is a tricycle wheeled mobile robot with three wheels, two fixed passive wheels and one steering driving wheel. First, kinematic and dynamic modeling for Automated Guided Vehicle is presented. Second, a controller that integrates two control loops, kinematic control loop and dynamic control loop, is designed for Automated Guided Vehicle to follow an unknown path. The kinematic control loop based on Fuzzy logic framework and the dynamic control loop based on two PID controllers are proposed. Simulation and experimental results are presented to show the effectiveness of the proposed controllers.

• 전자공학회논문지SC
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• 제37권3호
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• pp.9-18
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• 2000

본 논문에서는 구륜 이동 로봇의 기구학적 불완전성에 기인한 주행오차를 감소시키기 위한 방법을 제안한다. 별도의 표식장치 없이 엔코더만을 이용하여 구륜 반경과 차축변위를 보정한다. 또한 모터제어기의 가속해상도의 제약에 기인한 방향각 오차를 보상하기 위한 속도궤적을 제안한다. 제안된 속도궤적에 따라, 2개의 구동구륜 중 임의의 한 구륜의 속도는 주행거리에 따라 가변된다. 완전한 기구학적 보정이 이루어져도, 구륜 이동 로봇은 완전한 직선 주행을 할 수 없으며, 이러한 현상은 모터 제어기의 가속 해상도의 제약에 기인함을 보인다. 본 논문에서 제안된 방법의 유효성을 입증하기 위해 2 자유도 구륜 이동 로봇에 대해 실험을 수행하고 그 결과를 제시한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2066-2071
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• 2003

In this paper, we identify the isotropic configurations of an omnidirectional mobile robot with three caster wheels, depending on the selection of actuated joints. First, We obtain the kinematic model of a caster wheeled omnidirectional mobile robot(COMR) without matrix inversion. For a given task velocity, the instantaneous motion of each wheel is decomposed into two orthogonal instantaneous motions of the steering and the rotating joints. Second, with the characteristic length introduced, we derive the isotropy conditions of a COMR having $n({\ge}3)$ actuated joints, which are imposed on two Jacobian matrices, $A{\in}R^{n{\times}3}$ and $B{\in}R^{6{\times}6}$. Under the condition of $B{\propto}I_6$, three caster wheels should have identical structure with the length of the steering link equal to the radius of the wheel. Third, depending on the selection of actuated joints, we derive the conditions for $A^t$ $A{\propto}I_3$ and identify the isotropic configurations of a COMR. All possible actuation sets with different number of actuated joints and different combination of rotating and steering joins are considered.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.932-935
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• 1996

This paper proposes position estimation and path-tracking of a wheeled-mobile robot(WMR). Odometry and two distance measuring sensors are used to measure distance between guide wall and body and to locate its own position. And extended Kalman filter is introduced to fusion sensors and reduce noise. State feedback controller using the estimated position and path-tracking miles guidance control system. The computer simulation shows that proposed algorithm is well coincide with theoretical approach.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.187-190
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• 1997

In the past few years, many researchers are interesting of control of mobile robot with nonholonomic constraints. And tracking problems is important as well as regulation in nonholonomic system control. Some researchers have investigated the stable tracking control law for mobile robot. But, few results showed the globally asymptotically stable control method simply. So, we address the design of globally asymptotically stable tracking control law for mobile robot with nonholonomic velocity constraints using simple method. The stabilizability of the controller is derived by Lyapunov direct method. And we analyze the system responses according to the variation of control parameters in line tracking problem. It is derived that the responses represent no overshoot property in line tracking. Examples are two-wheeled mobile robot and car-like mobile robot and the simulation results represent the effectiveness of our method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.72-75
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• 2001

In this paper, the kinematic model and motion control of a joint-actuated mobile robot are analyzed. To take an efficient approach to the wheeled mobile robots, the relationship between wheel rotation and the contact point of the wheel is considered. It is shown that each addition of a joint to a mobile robot increases the degree of freedom(DOF) of mobile robot, and the way of joint attachment to a mobile robot is proposed. To get a solution of inverse kinematics of mobile robot, two types of approaches are proposed.

• 제어로봇시스템학회논문지
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• 제7권9호
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• pp.766-773
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• 2001

Omni-directional mobile robots have been popularly employed in several application areas. However, the kinematics for these systems have not been clearly identified, specially for redundantly actuated case which is common in omni-directional mobile robot such as the Nomadic model. For such mobile robot systems, exploitation of redundant actuation as well as singularity analysis has not been extensively addressed. In light of this fact, this paper introduces two different kinematic approaches for omni-directional mobile robots. Then, a singular-free load distribution scheme for redundantly actuated three-wheeled omni-directional mobile robot is proposed. Through simulation, several advantages of redundantly actuated mobile robot in aspect of singularity avoidance, minimization of torque norm, and exploiting several subtasks are presented.