• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.941-948
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• 2022

Disaster response robots are deployed to disaster sites where human access is difficult and dangerous. The disaster response robots explore the disaster sites prevent a structural collapse and perform lifesaving to minimize damage. It is difficult to operate robots in the disaster sites due to rough terrains where various obstacles are scattered, communication failures and invisible environments. In this paper, we developed a series connectable wheeled robot module. The series connectable wheeled robot module was developed into two types: an active driven robot module and a passive driven robot module. A wheeled robot was built by connecting the two active type robot modules and one passive type robot module. Two robot modules were connected by one DoF rotating joint, allowing the wheeled robot to avoid obstructions in a vertical direction. The wheeled robot performed driving and obstacle avoidance using only pressure sensors, which allows the wheeled robot operate in the invisible environment. An obstacle avoidance experiment was conducted to evaluate the performance of the wheeled robot consisting of two active driven wheeled robot modules and one passive driven wheeled robot module. The wheeled robot successfully avoided step-shaped obstacles with a maximum height of 80 mm in a time of 24.5 seconds using only a pressure sensors, which confirms that the wheeled robot possible to perform the driving and the obstacle avoidance in invisible environment.

• 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.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.5
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• pp.121-127
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• 2019

This paper proposes an operator-centric velocity generation and control algorithm for differential-drive mobile robots, which are widely used in many industrial applications. Most of the previous works use a robot centric velocity generation and control for the operators to control the differential-drive mobile robots, which makes the robot control difficult for the operators. Such robot-centric control can cause the increase of accidents and the decrease of work efficiency. The experimental results with a real differential-drive mobile robot testbed demonstrate the efficiency of operator-centric mobile robot control.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.81-84
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• 2007

바퀴구동형 로봇 메카니즘은 다양한 서비스 로봇에 활용되고 있는데, 이 로봇을 위하여 가장 기본적으로 요구되는 성능중의 하나는 등반능력과 관련된 구동모터의 사양을 결정하는 문제를 들 수 있다. 본 논문에서는 이러한 바퀴구동형 로봇 메카니즘의 등반능력을 고려하고, 경사면을 원활하게 주행하기 위한 필요조건을 제시하고자 한다. 결과적으로, 이러한 조건은 이동로봇 메카니즘의 설계에 유용하게 활용될 수 있을 것으로 기대한다.

• 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.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.304-309
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• 2014

In this paper, we design a hybrid wheeled and legged mobile robot with a waist joint. The proposed hybrid mobile robot is designed to have a hybrid structure with leg and wheel for the efficient movement in flat and uneven surfaces. The proposed robot have a waist joint that is used to stably transform from wheeled driving to legged walking of the robot and to overcome non-flat surface. In order to recognize various environments we use LRF sensor, PSD sensor, CCD camera. Also, a motion planning method for hybrid mobile robot with a waist joint is proposed to select wheeled driving motion and legged walking motion of the robot based the environment types. We verify the efficient mobility of the developed hybrid mobile robot through navigation experiments using the proposed motion planning method in various environments.

• 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.25 no.1
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• pp.1-6
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• 2015

In this paper, a fuzzy control method is used for balancing a single-wheel robot. A single-wheel robot controlled by the PD control method becomes easily unstable since the flywheel tends to lean against one direction. In the previous research, we have used the gain scheduling method. To remedy this problem, in this paper, a fuzzy compensation technique is proposed to compensate for the balancing angle. The fuzzy control method compensates offset values at the balancing angle to prevent the gimbal from falling against one direction. Experimental studies of the balancing control performance of a single-wheel mobile robot validate the proposed control method.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1327-1328
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• 2015

본 논문에서는 스틱 모델을 사용하여 외바퀴 로봇의 수직 방향에서 생기는 파라메트릭 진동을 시뮬레이션 분석하고, 분석된 결과를 바탕으로 제어 법칙을 유도한 다음, 실험을 통해 성능을 검증한다. 실험에 활용된 외바퀴 로봇은 수평 방향에 대해서는 비례미분제어기를 사용하고, 수직 방향에 대해서는 진동제어기를 활용한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.201-202
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• 2020

본 논문에서는 이륜 자동 균형 로봇을 제작하는데 초점을 맞추고 있다. 키워드는 아두이노와 PID컨트롤이다. 아두이노를 사용하여 로봇을 전체적으로 제어하였고 PID컨트롤로 로봇이 스스로 균형을 잡을 수 있도록 한다. 두 바퀴를 이용해 넘어지지 않고, 밸런스를 잡을 수 있도록 로봇의 바퀴, 프레임, 스텝모터, 드라이버 등을 구성하였고, 향후 이륜 자동 균형 로봇이 자유롭게 움직일 수 있도록 PID 정밀 제어를 하게 될 것이다.