• 전기학회논문지
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• 제63권1호
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• pp.139-144
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• 2014

This paper presents the novel design, implementation and control of a single-wheel mobile robot that can balance by using air power from ducted fans. All of the motions of the single-wheel mobile robot are actuated by air power instead of motor torques. Using air power allows to reduce the total weight of the robot. The complementary sensor fusion algorithm is introduced to estimate the angle correctly. After several design and development, the robot is tested for balancing in the roll direction and yawing motion. In addition, the balancing control of the robot on a single rope is tested to evaluate the control performance.

• 한국산업융합학회 논문집
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• 제19권2호
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• pp.81-87
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• 2016

This paper presents a new approach to control of stable motion of single wheel driving robot system of a pitch that is controlled by an in-wheel motor and a roll that is controlled by a reaction wheel. This robot doesn'thave any actuator for a yaw axis control, which makes the derivation of the dynamics relatively simple. The Lagrange equations was applied to derive the dynamic equations of the one wheel driving robot to implement the dynamic speed control of the mobile robot. To achieve the real time speed control of the unicycle robot, the sliding mode control and optical regulator are utilized to prove the reliability while maintaining the desired speed tracking performance. In the roll controller, the sigmoid-function based robust controller has been adopted to reduce the vibration by the situation function. The optimal controller has been implemented for the pitch control to drive the unicycle robot to follow the desired velocity trajectory in real time using the state variables of pitch angle, angular velocity, angle and angular velocity of the driving wheel. The control performance of the control systems from a single dynamic model has been illustrated by the real experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.255-257
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• 2007

In this paper, we develop a single wheeled robot that has one wheel to move. The single wheel robot is similar to a rolling disk relying on gyroscopic motions to balance. The Gyrobo consists of three actuators: a spin motor, a tilt motor and a drive motor. The spin motor spins a flywheel at high rate so that it provides the balancing stability to upright the robot. The tilt motor controls steering of the robot by gyroscopic effect. The drive motor make forward accelerated motion to the robot. We have built and tested the Gyrobo to turn and move forward.

• 한국지능시스템학회논문지
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• 제25권1호
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• pp.1-6
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• 2015

본 논문에서는 한 바퀴 이동로봇의 균형제어를 위해 퍼지방법을 사용하였다. PD제어를 사용하여 균형을 유지하는 한 바퀴 로봇은 시간이 지남에 따라 플라이휠이 한 방향으로 기울어지게 되고 결국에는 균형이 무너지는 현상이 발생한다. 선행연구에서는 이를 해결하기 위해 게인 스케줄링 방법을 사용하였다. 본 논문에서는 퍼지방법을 사용하여 균형 각도를 보상하므로 균형 제어 성능을 높이고자 하였다. 퍼지제어를 통해 desired offset의 각도를 보상하므로 김벌이 한쪽으로 흘러 넘어지는 현상을 보완하였다. 한 바퀴 구동 이동로봇의 균형제어 실험을 통하여 제안하는 제어방식의 성능을 검증하였다.

• 제어로봇시스템학회논문지
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• 제21권9호
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• pp.863-868
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• 2015

In this paper, the vibration of a single-wheel mobile robot is minimized by designing a filter. An AHRS (Attitude and heading reference system) sensor is used for measuring the state of the robot. The measured signals are analyzed using the FFT method to investigate the fundamental vibrational frequency with respect to the flywheel's speed of the gimbal system. The IIR notch filter is then designed to suppress the vibration at the identified frequency. After simulating the performance of the designated filter using the measured sensor data through extensive experiments, the filter is actually implemented in a single-wheel mobile robot, GYROBO. Finally, the performance of the designed filter is confirmed by performing the balancing control task of the GYROBO system.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.485-493
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• 2004

Open-loop position estimation methods are commonly used in mobile robot applications. Their strength lies in the speed and simplicity with which an estimated position is determined. However, these methods can lead to inaccurate or unreliable estimates. Two position estimation methods are developed in this paper, one using a single optical flow sensor and a second using two optical sensors. The first method can accurately estimate position under ideal conditions and also when wheel slip perpendicular to the axis of the wheel occurs. The second method can accurately estimate position even when wheel slip parallel to the axis of the wheel occurs. Location of the sensors is investigated in order to minimize errors caused by inaccurate sensor readings. Finally, a method is implemented and tested using a potential field based navigation scheme. Estimates of position were found to be as accurate as dead-reckoning in ideal conditions and much more accurate in cases where wheel slip occurs.

• 전자공학회논문지
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• 제53권11호
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• pp.123-129
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• 2016

본 논문에서는 외바퀴 로봇의 균형 제어 성능을 향상할 목적으로 외란관측기를 사용한다. 외란관측기의 설계는 역 공칭 모델 설계와 Q필터 설계의 두 과정으로 구성된다. 외바퀴 로봇의 역 공칭 모델을 역 스틱 모델로 부터 유도하고 역 공칭 모델의 안정화를 위한 Q필터를 설계한다. 이 과정에서 Q31의 형태를 갖는 필터를 설계하고 Q필터 시정수의 영향에 관한 실험적인 검증 결과를 제시한다. 시정수는 외란 억제 대역폭을 결정하는 역할을 하지만 외란 억제와 센서 잡음 내성은 상보적인 특성을 갖고 있다. 그러므로 전체 시스템을 고려하여 적절한 시정수가 선택되어야만 한다. 이를 해결하기 위해 3개의 서로 다른 시정수가 외란관측기에 각각 사용되었을 때의 제어 성능을 비교하는 실험을 수행한다. 결과 분석을 바탕으로 한 바퀴 로봇의 균형 제어에 대한 외란관측기 설계에 적합한 시정수 변수의 설계 범위를 제안한다.

• 제어로봇시스템학회논문지
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• 제19권1호
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• pp.1-9
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• 2013

This paper presents a new control algorithm for dynamic control of a unicycle robot. The unicycle robot motion consists of a pitch that is controlled by an in-wheel motor and a roll that is controlled by a reaction wheel pendulum. The unicycle robot doesn't have any actuator for a yaw axis control, which makes the derivation of the dynamics relatively simple. The Euler-Lagrange equation is applied to derive the dynamic equations of the unicycle robot to implement the dynamic speed control of the unicycle robot. To achieve the real time speed control of the unicycle robot, the sliding mode control and LQ regulator are utilized to guarantee the stability while maintaining the desired speed tracking performance. In the roll controller, the sigmoid-function based sliding mode controller has been adopted to minimize the chattering by the switching function. The LQR controller has been implemented for the pitch control to drive the unicycle robot to follow the desired velocity trajectory in real time using the state variables of pitch angle, angular velocity, angle and angular velocity of the wheel. The control performance of the two control systems form a single dynamic model has been demonstrated by the real experiments.

• 로봇학회논문지
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• 제17권2호
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• pp.216-220
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• 2022

This paper proposes an inspection robot that can operate on a single square rail. Various inspection robots have been developed to identify emergency situations in industrial environments, such as those involving fires or individuals with cardiac arrest. Because the robots must operate in wide areas and long tunnels, they are designed to move along a rail installed on the ceiling. Double rail track are typically used to ensure the stability of robot movement. However, the cost for installing a double rail track is nearly two times that for a single rail track. Moreover, it is challenging to install double rail tracks while ensuring the same curvature and interval between the two rails. Therefore, in this study, an inspection robot that operate on a single square rail track is developed. To ensure stable movement in the longitudinal and lateral directions, two passive guide parts are used, and the main active wheel is allowed to move on the upper side of the square rail. The prototype was manufactured, and experiments were performed for different robot velocities.

• 로봇학회논문지
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• 제9권4호
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• pp.250-257
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• 2014

In this paper, a new mobile robot, so called a rollerbot, is presented, which has single body and rugby-ball shaped roller wheel. A rollerbot has single point contact on ground and low energy consumption in motion because of the reduced friction. By changing center of mass using a balancing weight, a rollerbot is able to get steering force. The vertical position of mass center of the rollerbot in this paper is designed to lie inside radius of the roller wheel, so that to have stable equilibrium position. Thus, the posture and the steering control of the rollerbot can be easily done by changing the center of mass. Kinematics of the rollerbot is derived by transformation of differential motion in this paper.