• 한국지능시스템학회논문지
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• 제15권4호
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• pp.498-504
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• 2005

본 논문에서는 퍼지 로직을 이용한 수중 로봇의 충돌 회피를 제안하였다. VFF(Virtual Force Field) 방법은 이동 로봇 분야에서 널리 사용하고 있는 충돌 회피 알고리즘이다. 본 논문에서는 이를 수중 로봇의 자율 항해를 위한 형태로 변형시킨 Modified Virtual Force Field(MVFF)를 제시하였다. 보다 정교한 알고리즘을 위해서 퍼지 로직을 이용한 MVFF를 구성하였고, 이를 수중 로봇의 경로 유지와 충돌 회피에 적용하였다 퍼지 로직은 수중 로봇의 자율 항해 동안 직면하게 되는 다양한 상황들을 다루었다. 제안한 충돌 회피 알고리즘은 다수개의 고정 장애물에 대해서 좋은 성능을 제시하였다. 시뮬레이션 결과를 통해 제안된 방법이 수중 로봇의 충돌 회피에 효과적으로 적용될 수 있음을 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.17-17
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• 1996

An experimental research is a useful approach for realizing autonomous mobile robots to work in real environment. We are developing an autonomous mobile robot platform named "Yamabico" as a tool for experimental real world robotics research. The architecture of Yamabico is based on the concept of centralized decision making and functionally modularization. Yamabico robot has two level structure with behavior and function levels, and its hardware and software are functionally distributed for providing incremental development and good maintenancibility. We are using many Yamabico robots in our laboratory to realize the robust navigation technology for autonomous robots. The methodology for experimental and task-oriented approach of mobile robotics will be presented. And some experimental results of real world navigation in indoor and outdoor environment will be shown. be shown.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3105-3107
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• 1999

In this paper, we propose a new approach to autonomous wall-following of wheeled mobile robots using hybrid control system. The hybrid control approach IS introduced to the motion control of nonholonomic mobile robots in the Indoor navigation problems. In hybrid control architecture, the discrete states are defined by the user-defined constraints, and the reference motion commands are specified In the abstracted motions. The hybrid control system applied to motion planning and autonomous navigation with obstacle avoidance In indoor navigation problem. Simulation results show that it is an effective method for the autonomous navigation in indoor environments.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권2호
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• pp.95-103
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• 2016

In a dynamic environment autonomous robots often encounter unexpected situations that the robots have to deal with in order to continue proceeding their mission. We propose an adaptive goal-based model that allows cyber-physical systems (CPS) to update their environmental model and helps them analyze for attainment of their goals from current state using the updated environmental model and its capabilities. Information exchange approach utilizes Human-Agent-Robot-Machine-Sensor (HARMS) model to exchange messages between CPS. Model validation method uses NuSMV, which is one of Model Checking tools, to check whether the system can continue its mission toward the goal in the given environment. We explain a practical set up of the model in a situation in which homogeneous robots that has the same capability work in the same environment.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권1호
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• pp.20-25
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• 2002

This paper presents a genetic programming based evolutionary strategy for on-line adaptive learnable evolvable hardware. Genetic programming can be useful control method for evolvable hardware for its unique tree structured chromosome. However it is difficult to represent tree structured chromosome on hardware, and it is difficult to use crossover operator on hardware. Therefore, genetic programming is not so popular as genetic algorithms in evolvable hardware community in spite of its possible strength. We propose a chromosome representation methods and a hardware implementation method that can be helpful to this situation. Our method uses context switchable identical block structure to implement genetic tree on evolvable hardware. We composed an evolutionary strategy for evolvable hardware by combining proposed method with other's striking research results. Proposed method is applied to the autonomous mobile robots cooperation problem to verify its usefulness.

• 한국산학기술학회논문지
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• 제12권6호
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• pp.2760-2769
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• 2011

지능형 자율 로봇은 주어진 목표를 달성하기 위하여 계획을 수립한다. 계획은 로봇이 목표를 달성하기 위한 행위들의 나열이며 모든 행위들이 순차적으로 그리고 성공적으로 실행되었을 때 목표를 달성하게 된다. 그러나 복잡하고 역동적인 현실 세계에서는 여러 가지 요인에 의하여 발생할 수 있는 예상하지 못한 상황으로 인하여 로봇이 계획한 행위들을 더 이상 실행하지 못하는 경우가 발생할 수 있다. 그러므로 지능형 자율 로봇은 이러한 돌발 상황을 적절히 대처하여 주어진 임무를 성공적으로 완수할 수 있는 효과적인 처리 방법을 가지고 있어야 한다. 이정표 상태를 이용한 계획 보정 방법은 이러한 상황을 효과적으로 처리할 수 있는 방법으로서 다른 계획 보정 방법들의 장점을 가지고 있다. 본 논문은 이정표 상태를 생성하는 방법으로 후진 방법과 이정표 상태들을 구성하는 조건들에 가중치를 부여하는 방법을 제안한다. 오류 보정 방법은 부여된 가중치를 보정해야 할 조건들의 우선순위로 사용할 수 있다. 후진 방법에 의하여 생성된 이정표 상태들은 복잡정도가 낮고 또한 적당한 값의 가중치를 가지게 되므로 이정표를 이용한 효율적인 계획 오류 보정 방법을 보장하게 된다.

• 전자공학회논문지S
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• 제34S권3호
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• pp.33-45
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• 1997

In this paper, we propsoe a new method of th ecommunication system for cooperative behaviors and works in collective autonomous mobile robots. A communication function among the collective robots is essential to intelligent cooperative works. In genral, global communication is effective for small number of robots. However when the number of robot goes on increasing, this becomes difficult to be realized because of limited communication capacity and increasing amount of information to handle. And also the problems such as communciation interfeence and improper message transmission occur. So we propose local communication system based on infrared sensor to realize the cooperative behavior among robots as the solution of above problem. It is possible to prevent overflow of information and exchange of complex information by fusion sign board model which transmits the information to unspecified robots and message passing model which communicate a specific robot. And we formularize optimal communication range by analysis of information propagation mechanism from the proposed comunication system. At last we verify the effectiveness of the proposed communication system from example of cooperative works.

• 한국지능시스템학회논문지
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• 제14권6호
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• pp.699-704
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• 2004

본 논문에서는 인공 면역 시스템과 분류자 시스템에 기반하여 동작하는 자율분산로봇 시스템을 제안한다. 시스템에서 로봇들의 행동은 전역행동과 지역행동으로 분류된다. 전역행동은 환경에서 작업을 탐색하는데 이를 빠르게 수행하기 위하여 집합과 분산의 두 가지 행동으로 이루어져 있다 이때 인공 면역 시스템은 로봇이 어떤 행동을 선택하여 행동할 것인가를 결정한다. 지역행동은 탐색된 작업을 수행하는 부분으로서 어떤 로봇들이 협조행동을 할지를 학습하고, 학습한 결과에 따라 작업을 수행하는 행동을 한다. 이를 위해 분류자 시스템을 이용하여 각 로봇들은 주어진 작업에 대하여 학습을 한다. 제안된 시스템에서 학습 알고리즘은 주어지는 작업의 변화로봇들은 주어진 작업을 수행하기 위해 학습을 하고, 주어진 작업이 변할 경우 스스로 대처한다는 면에서 기존의 자율 분산 시스템보다 적응성에서 향상된 시스템이다.

• 로봇학회논문지
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• 제18권3호
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• pp.251-259
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• 2023

In the path traveling of differential-drive robots, the steering controller plays an important role in determining the path-following performance. When a robot with a pure-pursuit algorithm is used to continuously drive a right-angled driving path in an unstructured environment without turning in place, the robot cannot accurately follow the right-angled path and stops driving due to the ground and motor load caused by turning. In the case of pure-pursuit, only the current robot position and the steering angle to the current target path point are generated, and the steering component does not reflect the speed plan, which requires improvement for precise path following. In this study, we propose a driving algorithm for differentially driven robots that enables precise path following by planning the driving speed using the radius of curvature and fusing the planned speed with the steering angle of the existing pure-pursuit controller, similar to the Model Predict Control control that reflects speed planning. When speed planning is applied, the robot slows down before entering a right-angle path and returns to the input speed when leaving the right-angle path. The pure-pursuit controller then fuses the steering angle calculated at each path point with the accelerated and decelerated velocity to achieve more precise following of the orthogonal path.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권1호
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• pp.17-21
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• 2007

Multi-Agent Robotic System (MARS) is a system that independent autonomous robots in the restricted environments infer their status from pre-assigned conditions and operate their jobs through the cooperation with each other. In the MARS, a robot contains sensor part to percept the situation around themselves, communication part to exchange information, and actuator part to do given work. Especially, in order to cooperate with other robots, communicating with other robots is one of the essential elements. Because Bluetooth has many advantages such as low power consumption, small size module package, and various standard protocols, Bluetooth is rated as one of the efficient communicating technologies which can apply to small-sized robot system. In this paper, we will develop Bluetooth communicating system for autonomous robots. For the purpose, the communication system must have several features-separated module, flexible interface. We will discuss how to construct and what kind of procedure to develop the communicating system.