• Journal of the Institute of Convergence Signal Processing
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• v.23 no.1
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• pp.21-27
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• 2022

Traditional automobile or 2-wheeled robot have limitations on mobility because of their mechanical structure. As traditional automobile is being replaced by electric cars, robot technology is applied to the car industry. In robotics, many researchers worked on omnidirectional mobile robot and produced lots of noticeable results. However in many of the results, specialized wheels such as Mecanum wheels are required. That imposes restrictions on robot speed and outdoor driving. We proposed a 2-wheeled modular robot that has omnidirectional mobility without using specialized wheels. In this paper, we propose a 4-wheeled omnidirectional mobile robot that consists of those two modular robots. The proposed robot adopts electric brakes to combine wheel housings and the robot body or to separate wheel housings from the robot body. Two absolute-type encoders and four incremental encoders are used to control the position of the wheel housing and velocities of the wheels. The proposed robot has omnidirectional mobility and can move fast and outdoor with normal tire wheels. We implemented the proposed robot and the feasibility and stability of the robot is verified by two separate experiments.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.279-280
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• 2011

2바퀴이상의 로봇은 중심점을 기준으로 안정화가 이루어진다. 그러나 2바퀴이하의 로봇으로 수직 자세를 유지하기 위해서는 로봇자체를 기울여 중심점을 이동하므로 수평을 유지할 수 있다. 그러나 이러한 중심점의 이동은 속도나 방향성분이 같이 출력되므로 정확한 센서의 계산이 요구되고 정밀한 제어를 필요로 한다. 또한 많은 구조물로 인해 장애물 인식 및 자율주행 알고리즘 등이 필요하며 장시간 정보획득과 무인기 연동을 위한 빠른 움직임을 가져야한다. 위의 2조건을 만족하기 위한 구성으로 최근들어 두 바퀴를 가지는 모바일 역진자 로봇에 대한 연구가 활발히 이루어지고 있다. 이는 서비스 및 주행 로봇의 알고리즘이 휴머노이드에서 모바일 역진자 로봇으로 변화되었기 때문이다. 모바일 역진자 로봇은 휴머노이드에 비하여 사용되는 모터의 수가 적고 균형을 잡으려면 관절마다 값비싼 고성능 모터가 필요하며 이를 가동하려면 전력도 많이 소모되며 대용량 배터리를 장착할 수밖에 없게 된다. 반면 바퀴로 움직이는 로봇은 전력이 적게 들고 이동도 쉽다. 따라서 본 연구에서는 IMU를 이용한 간단하면서도 정확한 센서의 연산 방법과 이를 이용한 자세제어 방법을 연구한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.89-98
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• 2017

The control moment gyroscope(CMG) can be used for essential balancing control of a one-wheeled mobile robot. A single-gimbal CMG has a simple structure and can supply strong restoring torque against external disturbances. However, the CMG generates unwanted directional torque also besides the restoring torque; the unwanted directional torque causes instability in the one-wheeled robot control system that has high rotational degrees of freedom. This study proposes a control system for a one-wheeled mobile robot by using a CMG scissored pair to eliminate the unwanted directional torque. The well-known LQR control algorithm is designed for robustness against modeling error in the dynamic motion equations of a one-wheeled robot. Computer simulations for 3D nonlinear dynamic equations are carried out to verify the proposed control system with the CMG scissored pair and the LQR control algorithms.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1447-1454
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• 1991

본 로봇은 wheeled type과 legged type의 장점을 함께 가지고 있으므로 주행 속도가 빠르며 환경적응력이 좋다. 기존 로봇과 비교할때 Y.Icihkawa등이 개발한 HLV와 가장 유사하지만 모터 3개로 6개의 바퀴-다리 유닛을 구동하므로 모터15개로 5개의 바퀴-다리유닛을 구동하는 Ichikawa HLV와 동력전달구조에서 많이 상이하다. 뿐만아니라 본 로봇은 3개의 모터만 사용했기 때문에 주행제어가 훨씬 간단하고 제작 비가 저렴하며 장애물 및 계단승강시 걸음새가 훨씬 간단하다.(Ichikawa HLV 경우 뒷 쪽 2개의 다리를 동시에 들 수 없기 때문에 계단 승강시 몸체 회전을 적절하게 섞어야 한다.)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.522-525
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• 2007

Most big difference of existing robot and biped robot stays at the leg. The wheel is very efficient with the portability than the leg. However biped robot can accomplish many role height. But The two thing which we take the center to the leg and walk to the stability is not easy work. Therefore this proposal make efforts that we try to find technical element for the walking of the robot through its design and implementation.

• Journal of Advanced Navigation Technology
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• v.18 no.2
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• pp.134-141
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• 2014

Mobile robots use various sensors for navigation such as wheel encoder, vision sensor, sonar, and laser sensors. Dead reckoning is used with wheel encoder, resulting in the accumulation of positioning errors. For that reason wheel encoder can not be used alone. Too much information of vision sensors leads to an increase in the number of features and complexity of perception scheme. Also Sonar sensor is not suitable for positioning because of its poor accuracy. On the other hand, laser sensor provides accurate distance information relatively. In this paper we propose to extract the angular information from the distance information of laser range finder and use the Kalman filter that match the heading and distance of the laser range finder and those of wheel encoder. For laser scanner with one feature point error may increase much when the feature point is variant or jumping to a new feature point. To solve the problem, we propose to use two feature points and show that the positioning error can be reduced much.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.77-84
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• 2004

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline, and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application, as the attaching force of the vehicle can be affected by its posture.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.131-132
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• 2011

현 시대는 로봇의 시대라 할 만큼 다채로운 로봇들이 개발되고 있으며, 인간의 기능들을 본 떠 만든 로봇 암(Robot arm: manipulator)과 워킹로봇(Walking robot: biped robot, quadruped robot, popping robot, etc.)물체인식 및 물체 추적 로봇(Tracking robot with image processing -. Domo robot, MIT.)이나 곤충과 동물 등의 생체 로봇에 대한 개발 또한 진행하고 있다. 지능형 이동로봇에서 가장중요하고 기본이 되는 기술인 무선통신망을 이용한 통신 기술과 지표면을 걷는 워킹로봇이 아닌 개활지나 밀폐된 공간에서 주행이 자유롭고 속도 및 주변 반응에 대해서 즉시 반응할 수 있는 장점을 가져 개발이용이한 바퀴를 이용한 2축 이동로봇에 관하여 연구하였다. 본 연구는 무선통신망을 이용하여 인터넷이 되는 곧 이면 어디서든 원격제어를 통하여 이동로봇을 전진, 후진, 좌회전. 우회전 및 속도제어 위치제어를 할 수 있고 GPS로 로봇의 위치와, 카메라를 이용하여 영상자료를 수집하고 센서를 이용하여 장애물 감지 및 자율주행 하는 등 여러 분야에 응용 할 수 있는 로봇을 연구하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1676-1681
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• 2003

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline. and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application. as the attaching force ortho vehicle can be affected by its posture.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.3
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• pp.28-34
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• 2014

In this paper, we propose a trajectory tracking controller for a two-wheeled mobile robot (WMR) with nonholonomic constraints using a fuzzy sliding-mode controller-based hyperbolic function. The proposed controller is composed of two separate controllers. The sliding-mode controller is used for attitude control of the WMR, and the fuzzy controller-based hyperbolic function is designed to adjust the reach time of the sliding-mode control. Simulation results on a linear and a circular trajectory show that the proposed controller improves the control performance. The proposed controller reduces the reach time by as much as 47% compared to the controller proposed by Xie et al.