• 제어로봇시스템학회논문지
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• 제18권6호
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• pp.532-539
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• 2012

This paper proposes a balancing and driving control system for a bicycle robot. A reaction wheel pendulum control method is adopted to maintain the balance while the bicycle robot is driving. For the driving control, PID control algorithm with a variable gain adjustment has been developed in this paper, where the gains are heuristically adjusted during the experiments. To measure the angles of the wheels the encoders are used. For the balancing control, a roll controller is designed with a non-model based algorithm to make the shortest cycle. The tilt angle is measured by the fusion of the acceleration and gyroscope sensors, which is used to generate the control input of the roll controller to make the tilt angle zero. The performance of the designed control system has been verified through the real experiments with the developed bicycle robot.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.1006-1013
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• 2011

In this paper, we propose an optimal posture control law for an unmanned bicycle by deriving linear bicycle model from fully nonlinear differential equations. We calculate each equilibrium point of a bicycle under any given turning radius and angular speed of rear wheel. There is only one equilibrium point when a bicycle goes straight, while there are a lot of equilibrium points in case of turning. We present an optimal equilibrium point which makes the leaning input minimum when a bicycle is turning. As human riders give rolling torque by moving center of gravity of a body, many previous studies use a movable mass to move center of gravity like humans do. Instead we propose a propeller as a new leaning input which generates rolling torque. The propeller thrust input makes bicycle model simpler and removes input magnitude constraint unlike a movable mass. The proposed controller can hold optimal equilibrium points using both steering input and leaning input. The simulation results on linear control for circular motion are demonstrated to show the validity of the proposed approach.

• 한국지능시스템학회논문지
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• 제23권4호
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• pp.332-340
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• 2013

본 논문은 실제 환경과 모의실험에서 이동 로봇의 위치 추정과 자율주행 구현을 위한 프로그래밍 툴킷에 대해 서술한다. 기존에 사용되고 있는 라이브러리들은 복잡성과 유용성의 결함으로 사용에 어려움이 있다. 제안된 툴킷은 추측항법, 운동 모델, 측정 모델, 그리고 방향 또는 지향각의 연산을 위한 툴킷들로 구성된다. 추측 항법과 운동 모델은 차륜 구동 로봇과 전, 후륜 속도에 의한 이륜차 로봇에 대해 다룬다. 툴킷들은 실제 환경과 모의실험에서의 자율주행을 위해 사용 가능하다. 툴킷의 사용가능성은 모의실험의 결과와 실제 실험의 결과를 보임으로써 증명한다. 제안된 툴킷은 이동 로봇의 위치추정, 지도 작성, 그리고 장애물 회피와 같은 자율주행의 구성 기술을 위한 알고리즘의 검사에 사용할 수 있을 것으로 기대된다.

• 로봇학회논문지
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• 제8권4호
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• pp.292-297
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• 2013

This paper presents a new method of kinematic modeling for autonomous bicycle by using the differential motion transformation. Kinematic model is indispensable to trajectory planning and control for an autonomous mobile robot. The conventional methods of kinematic modeling for an autonomous bicycle depend on intuition by geometry. On the contrary, the proposed method in this paper is based on the systematic differential motion transformation, thus applicable to various types of autonomous bicycles. The differential motion transformation gives Jacobian between two coordinate frames and the velocity kinematics as a result.

• 제어로봇시스템학회논문지
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• 제12권2호
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• pp.161-167
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• 2006

In this paper, lateral force control of a mobile robot with slip is presented. First, the bicycle model of a mobile robot is derived for the front steering. Second, impedance force control algorithm is applied to regulate contact force with environment. The desired distance is specified conservatively inside the environment to guarantee to make contact. Different stiffness of environment has been tested for force tracking task. Simulation results show that the proposed control algorithm works well to maintain desired contact force on the environment.

• 한국전자통신학회논문지
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• 제8권3호
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• pp.421-432
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• 2013

본 논문은 이동 로봇의 자율 주행을 위한 중요한 기술 중 하나인 위치 추정을 위한 함수 구현에 관해 서술되었다. 기존의 로봇 자율주행용 함수 라이브러리 중 일부는 모의실험에만 사용할 수 있기 때문에 실제 적용에 제한이 따른다. 본 논문은 실내 이동 로봇의 위치 추정을 위해 사용할 수 있는 함수의 개발에 중점을 두었다. 함수들은 추측항법, 이동 로봇의 운동 모델, 거리 측정 센서의 측정 모델, 그리고 빈번히 사용되는 방향 관련 연산에 대해 구현되었다. 구현된 함수들은 다양한 로봇과 센서에 적용할 수 있다. 사용자는 적절한 함수를 선택하여 로봇 운동과 센서 측정 불확실성의 다양한 유형을 구현할 수 있다. 구현된 함수들은 모의실험과 실제 실험을 통해 시험 및 증명되었다.

• Journal of Positioning, Navigation, and Timing
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• 제11권3호
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• pp.209-215
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• 2022

As intelligent autonomous driving vehicle development has become a big topic around the world, accurate reference dynamics estimation has been more important than before. Current systems generally use speed and heading information sensed from a distant point as a vehicle reference dynamic, however, the dynamics between different points are not same especially during rotating motions. In order to estimate properly estimate the reference dynamics from the information such as velocity and heading sensed at a point distant from the reference point such as center of gravity, this study proposes estimating reference dynamics from any location in the vehicle by combining the Bicycle and Ackermann models. A test system was constructed by implementing multiple GNSS/INS equipment on an Robot Operating System (ROS) and an actual car. Angle and speed errors of 10° and 0.2 m/s have been reduced to 0.2° and 0.06 m/s after applying the suggested method.

• 로봇학회논문지
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• 제18권1호
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• pp.93-98
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• 2023

In this paper, the development of an autonomous electric vehicle for logistics with a robotic arm is introduced. The manual driving electric vehicle was converted into an electric vehicle platform capable of autonomous driving. For autonomous driving, an encoder is installed on the driving wheels, and an electronic power steering system is applied for automatic steering. The electric vehicle is equipped with a lidar sensor, a depth camera, and an ultrasonic sensor to recognize the surrounding environment, create a map, and recognize the vehicle location. The odometry was calculated using the bicycle motion model, and the map was created using the SLAM algorithm. To estimate the location of the platform based on the generated map, AMCL algorithm using Lidar was applied. A user interface was developed to create and modify a waypoint in order to move a predetermined place according to the logistics process. An A-star-based global path was generated to move to the destination, and a DWA-based local path was generated to trace the global path. The autonomous electric vehicle developed in this paper was tested and its utility was verified in a warehouse.