• 제어로봇시스템학회논문지
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• 제17권7호
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• pp.647-650
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• 2011

This paper presents the development of roll replacement robot system for wire-rod press rolls. The roll replacement robot system consist of a palletized railway truck, a 6-DOF industrial robot manipulator, a roll changing tool and a hydraulic power system. Results of simulation and pilot experiment show the roll changing task can be successfully automated using proposed robot system.

• 한국항해항만학회지
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• 제33권5호
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• pp.323-330
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• 2009

병렬기구를 이용하여 항만공사를 위한 수중로봇을 개발하였다. 수중으로 큰 피복석을 옮기기 위해 수중로봇은 크레인에 의해 권양된다. 수중로봇의 요오와 피치운동은 유압 실린더에 의해 제어되지만 롤 운동은 제어되지 않는다. 롤 운동을 위해 로봇 양쪽에 프로펠러가 장착되어 제어된다. 본 논문은 수중로봇의 롤 운동제어에 관한 것이다. 롤 운동 각도를 측정하기 위해 자이로 센서가 사용되었다. 로봇의 롤 운동을 2차 비선형 시스템으로 나타내고 반복 리스트 스퀘어 방법과 적응인식 방법으로 동적 모델을 찾았다. 동적 모델로 외란을 보상하기 위한 제어입력을 계산하고 PD 제어, 반복 리스트 스퀘어 모델 베이스 제어, 적응 모델 베이스 제어를 롤 운동제어에 적용했다. 수중로봇의 시스템을 설명하고 제안한 제어기의 시뮬레이션과 실험결과를 보인다.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.688-694
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• 2010

This paper presents a gravity compensator for the manipulator of a service robot. The manipulator of a service robot is operated with low velocity for the safety reason in most cases. In this situation gravitational torques generated by the mass of links are often much greater than dynamic torques for motion. A gravity compensator can counterbalance the gravitational torques, thereby enabling to utilize relatively low power motors. In this paper the gravity compensation for the roll-pitch rotation is considered which is often used for the shoulder joints of the manipulator of a service robot or humanoid robot. A gimbals is implemented and two 1-dof gravity compensators are equipped at the base. One compensates the gravitational torque at the roll joint and another provides the compensational torque for the gimbals. Various analyses showed that the proposed compensator can counterbalance the gravitational torques of 87% at the pitch joint and 50% at the roll joint. It is verified from dynamic simulations that the proposed compensator effectively counterbalances the gravitational torques.

• 제어로봇시스템학회논문지
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• 제18권3호
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• pp.275-284
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• 2012

This paper proposes an attitude and direction control of a single wheel balanced robot. A unicycle robot is controlled by two independent control laws: the mobile inverted pendulum control method for pitch axis and the reaction wheel pendulum control method for roll axis. It is assumed that both roll dynamics and pitch dynamics are decoupled. Therefore the roll and pitch dynamics are obtained independently considering the interaction as disturbances to each other. Each control law is implemented by a controller separately. The unicycle robot has two DC motors to drive the disk for roll and to drive the wheel for pitch. Since there is no force to change the yaw direction, the present paper proposes a method for changing the yaw direction. The angle data are obtained by a fusion of a gyro sensor and an accelerometer. Experimental results show the performance of the controller and verify the effectiveness of the proposed control algorithm.

• 제어로봇시스템학회논문지
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• 제19권8호
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• pp.688-693
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• 2013

This paper proposes a new method on attitude control of an underwater robot by using five ABTs (Attitude Ballast Tank). A pipe is connected to the bottom of the ABTs and transfers water by a pump, while another pipe is connected to the top of the ABT to transfer air. The buoyancy center of the underwater robot can be changed by means of the water transfer. This way, the attitude of the underwater robot can be maintained and/or controlled as desired. The changes of the center of gravity and the buoyancy central are estimated by a Lagrangian function which is similar to that for an inverted pendulum. The controller in this paper is designed by modeling of the underwater robot and selecting suitable gains of a PD controller which has fast response characteristics. This paper shows the possibility of the attitude control of an underwater robot by changing the center of gravity and the buoyancy center of the robot. Moreover, experimental results verify that the controller is effective in maintaining Roll/Pitch of the underwater robot with very low power consumption.

• 로봇학회논문지
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• 제11권4호
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• pp.256-261
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• 2016

An insect-like flapping-wing flying-robot should be able to produce flight forces and control moments at the same time only by flapping wings, because there is no control surface at tail just like an insect. In this paper, design principles for the flapping mechanism and control moment generator are briefly explained, characteristics measured force and moment generations of the robot are presented, and finally controlled flight of the flying robot is demonstrated. The present insect-like robot comprises a lightweight flapping mechanism that can produce a flapping angle larger than $180^{\circ}$ and a control moment generator that produces pitch, roll, and yaw moments by adjusting location of the trailing edges at the wing roots. The measured force and moment data show that the control input angles less than $9^{\circ}$ would not significantly reduce the vertical force generation. It is also observed that the pitch, roll, and yaw control moments are produced only by the corresponding control input. The simple PID control theory is used for the controlled flight of the flying robot, controlling pitch, roll, and yaw motions. The flying robot successfully demonstrated controlled flight for about 40 seconds.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.629-630
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• 2013

• 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.

• 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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.209-214
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• 2003

We developed a new type of human-sized BWR (biped walking robot), named KUBIR1 which is driven by the closed-chain type of actuator. A new type of the closed-chain actuator for the robot is developed, which is composed of the four-bar-link mechanism driven by the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of 6 D.O.F joints. For front walking, three pitch joints and one roll joint at the ankle. In addition to this, one yaw joint for direction change, and another roll joint for balancing the body are attached. Also, the robot has two D.O.F joints of each hand and three D.O.F. for eye motion. There are three actuating motors for stereo cameras for eyes. In all, a 18 degree-of-freedom robot was developed. KUBIR1 was designed to walk autonomously by adapting small 90W DC motors as the robot actuators and batteries and controllers are on-boarded. The whole weight for Kubir1 is over 90Kg, and height is 167Cm. In the paper, the performance test of KUBIR1 will be shown.