• 한국인터넷방송통신학회논문지
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• 제9권6호
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• pp.55-61
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• 2009

본 논문은 유비쿼터스 센서 네트워크와 이동로봇에 내장된 회전 센서를 이용하여 실내에서의 이동로봇에 위치를 인식하고 이를 바탕으로 인터넷을 통한 원격제어 시스템 개발을 제안한다. 사용한 USN(Ubiquitous Sensor Network)은 ZigBee 기반으로 위치 인식 엔진을 탑재하고 RSSI(Received Signal Strength Indicator) 신호를 사용하여 노드간의 거리를 측정한다. 본 논문에서는 노드 간의 정확한 거리 정보를 얻고 이를 바탕으로 위치를 추정하기 위해 실험 입 출력 데이터를 가지고 퍼지 모델을 구하였고 거리의 오차를 수정하였다. 또한, RSSI 값의 부정확으로 인한 위치 인식의 오류를 보정하기 위해 이동로봇에 내장된 회전 센서를 이용하여 이동로봇의 좌표를 구하고 이를 위치 좌표의 보정에 사용하여 위치 인식의 정확성을 개선하였다. 제안된 방법에 의한 위치 인식을 기반으로 인터넷을 통한 원격제어 시스템을 개발하였다. 제안된 방법이 USN에 의해 추정된 위치 정보만을 사용하는 경우보다 정확하게 이동로봇의 위치를 추정하고 인터넷을 통한 원격 주행이 가능함을 보였다.

• 한국지능시스템학회논문지
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• 제13권6호
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• pp.692-697
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• 2003

지난 몇 년 동안 인터넷기반 원격제어 연구에 대한 관심이 높아지고 있다. 본 논문에서는 인터넷기반 원격 제어시스템을 구현한다. 로봇의 주변환경 및 제어 정보를 강인하게 전송하기 위하여 데이터를 패킷 형태로 만든다. 또한 매우 큰 용량을 갖는 영상 데이터를 전송하기 위하여 JPEG 압축 알고리즘을 이용한다. 인터넷 기반 원격제어의 주된 문제점은 데이터 전송 지연 또는 데이터 손실이다. 이러한 특수한 문제를 해결하기 위하여 2-layer fuzzy controller를 장착한 자율이동로봇을 소개한다. 그리고, 컬러 인식 시스템을 구현하여 로봇을 물체를 인지할 수 있도록 하였다. 다양한 입력 센서가 장착된 로봇에 2-layer fuzzy controller를 적용하여 그 효율성을 입증한다. 2-layer fuzzy controller는 다양한 입력과 출력을 갖는 로봇을 강인하게 제어할 수 있고 제어 비용도 낮기 때문에 그것이 다양한 분야에 적용되어 질 것으로 기대된다.

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1290-1303
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• 2005

In this research, a remote control system has been developed and implemented, which combines autonomous obstacle avoidance in real-time with force-reflective tele-operation. A tele-operated mobile robot is controlled by a local two-degrees-of-freedom force-reflective joystick that a human operator holds while he is monitoring the screen. In the system, the force-reflective joystick transforms the relation between a mobile robot and the environment to the operator as a virtual force which is generated in the form of a new collision vector and reflected to the operator. This reflected force makes the tele-operation of a mobile robot safe from collision in an uncertain and obstacle-cluttered remote environment. A mobile robot controlled by a local operator usually takes pictures of remote environments and sends the images back to the operator over the Internet. Because of limitations of communication bandwidth and the narrow view-angles of the camera, the operator cannot observe shadow regions and curved spaces frequently. To overcome this problem, a new form of virtual force is generated along the collision vector according to both distance and approaching velocity between an obstacle and the mobile robot, which is obtained from ultrasonic sensors. This virtual force is transferred back to the two-degrees-of-freedom master joystick over the Internet to enable a human operator to feel the geometrical relation between the mobile robot and the obstacle. It is demonstrated by experiments that this haptic reflection improves the performance of a tele-operated mobile robot significantly.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권2호
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• pp.161-165
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• 2003

In this paper, we investigate the issues on the design and implementation of tele-operation system based on the haptic interface. Here, the 3-DOF haptic device and the X-Y-Z stage are employed as master controller and slave system respectively. For this master-slave system, the force feedback algorithm, the modeling of virtual environments and the control method of X-Y-Z stage are presented. In this paper, internet network is used for data communication between master and slave. We construct virtual environment of the real convex surface from the force-feedback in controlling the X-Y-Z stage and measuring the force applied by the 3-DOF haptic device.

• 한국정밀공학회지
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• 제19권12호
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• pp.70-77
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• 2002

Necessity of the tole-operation has been increased in many fields. Since the Internet is inexpensive and available all over the world, it is a strong candidate for the transmission media of the tole-operation. However, the Internet has random time delays that may cause instability in the system especially if the tole -operation is bilateral. In the past few years many attempts have been made to overcome the random time delay, So far, they are still insufficient in terms of performance. The ‘Variable holding time’ is introduced to improve the performance of the ‘Event based tole-operation’ which controls a system with a non-time action reference. By holding each event for proper time, the system can quickly respond and be stabilized. The proper holding time should be selected based on the characteristics of the task that the system performs. The factors that reflect those characteristics are investigated. The fuzzy logic is employed to obtain the proper holding time for each event while the tole-operation system is in operation. The experimental results presented in this paper verify effectiveness of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.502-504
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• 2004

With rapidly growing of computer and internet technology, Internet-based tote-operation of robotic systems has created new opportunities in resource sharing, long-distance learning, and remote experimentation. In this paper, remote control system of a mobile robot through the internet has been designed. The internet users can access and command a mobile robot in the real time, receiving the robot's sensor data. The overall system has been tested and its usefulness shown through the experimental results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1171-1172
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• 2008

In this paper, we investigate the issues on the design and implementation of tele-operation system based on the haptic interface. Here, the 3-DOF haptic device and the X-Y-Z stage are employed as master controller and slave system respectively. For this master-slave system, the force feedback algorithm, the modeling of virtual environments and the control method of X-Y-Z stage are presented. In this paper, internet network is used for data communication between master and slave.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.44.1-44
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• 2001

This paper discusses the interacting mobile robots for tele-operation system using the world wide web. In multi-agent and web-based teleoperation environment the problem of communication delay must be solved for the efficient and robust control of the system. The standard graphic user interface(GUI)is implemented using Java Programing language. The web browser is used to integrate the virtual environment and the standard GUI(Java applet) in a single user interface. Users can access a dedicated WWWserver and download the user interface. Reinforcement learning is applied to indirect control in order to autonomously operate without the need of human intervention. Java application has been developed to communicate and control multi robots using WWW. The effectiveness of our multi robots system is verified by simulation and experiments ...

• 동력기계공학회지
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• 제13권2호
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• pp.71-82
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• 2009

This paper presents a real-time haptic rendering method for a realistic force feedback in a remote environment with varying communication time-delay. The remote environment is assumed as a virtual environment based on a computer graphics, for example, on-line shopping mall, internet game and cyber-education. The properties of a virtual object such as stiffness and viscosity are assumed to be unknown because they are changed according to the contact position and/or a penetrated depth into the object. The DARMAX model based output estimator is proposed to trace the correct impedance of the virtual object in real-time. The output estimator is developed on the input-output relationship. It can trace the varying impedance in real-time by virtue of P-matrix resetting algorithm. And the estimator can trace the correct impedance by using a white noise that prevents the biased input-output information. Realistic output forces are generated in real-time, by using the inputs and the estimated impedance, even though the communication time delay and the impedance of the virtual object are unknown and changed. The generated forces trace the analytical forces computed from the virtual model of the remote environment. Performance is demonstrated by experiments with a 1-dof haptic device and a spring-damper-based virtual model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.622-627
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• 2003

The existing remote control system have some inherent disadvantage of direct control in the limit range. In some special cases, for example, a power apparatus, an unmanned factory, a nuclear factory, a security management system, the tele-operation is needed to control remote robot without limit space. This field is based on the Internet communication. Because the Internet is constructed all over the world. And it is possible that we control remote mobile robot in the long distance. In this paper, we developed a remote control system. This system is divided into two primary parts. These are local site and remote site. There are the moving robot and web server in the remote site and there is the robot control device in local site. The moving robot is moved by two stepper motors and the robot control device consists of SA-1100 micro controller and embedded Linux. And this controller is an embedded system. Public personal computer which is connected the Internet is used for the web server. The web server provides the mobile robot control interface program to the remote controller and captures the image for feedback information. In the whole system, a robot control device is connected with moving robot and web server through the Internet. So the operator can control the moving robot in the distance through the Internet.