• Journal of Communications and Networks
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• v.9 no.3
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• pp.296-311
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• 2007

Mobile multi-robot teams are useful in many critical applications such as search and rescue. Explicit communication among robots in such mobile multi-robot teams is useful for the coordination of such teams as well as exchanging data. Since many applications for mobile robots involve scenarios in which communication infrastructure may be damaged or unavailable, mobile robot teams frequently need to communicate with each other via ad hoc networking. In such scenarios, low-overhead and energy-efficient routing protocols for delivering messages among robots are a key requirement. Two important primitives for communication are essential for enabling a wide variety of mobile robot applications. First, unicast communication (between two robots) needs to be provided to enable coordination and data exchange. Second, in many applications, group communication is required for flexible control, organization, and management of the mobile robots. Multicast provides a bandwidth-efficient communication method between a source and a group of robots. In this paper, we first propose and evaluate two unicast routing protocols tailored for use in ad hoc networks formed by mobile multi-robot teams: Mobile robot distance vector (MRDV) and mobile robot source routing (MRSR). Both protocols exploit the unique mobility characteristics of mobile robot networks to perform efficient routing. Our simulation study show that both MRDV and MRSR incur lower overhead while operating in mobile robot networks when compared to traditional mobile ad hoc network routing protocols such as DSR and AODV. We then propose and evaluate an efficient multicast protocol mobile robot mesh multicast (MRMM) for deployment in mobile robot networks. MRMM exploits the fact that mobile robots know what velocity they are instructed to move at and for what distance in building a long lifetime sparse mesh for group communication that is more efficient. Our results show that MRMM provides an efficient group communication mechanism that can potentially be used in many mobile robot application scenarios.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.142-147
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• 1988

Free-path-type guidance system does not need a hardwired path in the environment so that it gives a mobile robot a flexible path. ln this study to achieve the free-path-type guidance system for a mobile robot which is steered by the differential steering of both drive forewheels, position recognition systems are constructed using odometer system as an internal position sensor. Two odometer systems, a auxiliary wheel odometer and a 2-encoder odometer system are constructed and path following algorithms using these odometer systems are designed and experimented. PID control type is adopted in the path following algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1395-1401
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• 2005

Mobile manipulator is a robot that has mobility and manipulability with the combination of the task robot and mobile robot. One of the most important feature of the Mobile Manipulator is redundant freedom. Using the redundant freedom, Mobile Manipulator can move various mode, perform dexterous motion. It can have the wider workspace and better performance in avoidance of singularity and obstacle than the fixed base structured robot. Cooperation control using the Mobile Manipulator improves the performance of the robot with redundant freedom in workspace. In this paper, configuration control of the Mobile Manipulator has been studied using Task Segment and TOMM(Task-Oriented Manipulability Measure). For verifying the proposed algorithm, we implemented a mobile manipulator, PURL-II, which is composed of a mobile robot with 3DOF and a task robot with SDOF.

• The Journal of Korea Robotics Society
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• v.4 no.4
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• pp.289-297
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• 2009

This paper presents the development and control of a two wheeled car-like mobile robot using balancing mechanism whose heading control is done by turning the handle. The mobile inverted pendulum is a combined system of a mobile robot and an inverted pendulum system. A sensor fusion technique of low cost sensors such as a gyro sensor and a tilt sensor to measure the balancing angle of the inverted pendulum robot system accurately is implemented. Experimental studies of the trajectory following control task has been conducted by command of steering wheel while balancing.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.1-6
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• 1992

An autonomous mobile robot has been developed which can follow a travel map drawn on a monitor screen using a software. The robot works as an exhbition guide making announcement regrading the events to take place or introducing the products on display. This mobile robot computes the world position and heading direction through camera image, ultrasonic and infrared sensors in real time using specially designed algorithm. This mobile robot will be exhibited at '93 Tae-Jeon EXPO for an exhibition guide, and will be used in a plant or a hospital for materials handling purposes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.784-789
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• 1994

In the mobile robot research, monitoring the present status and self-navigating the robot in various environment are signifiant. This paper treates a navigation algorithm using a fuzzy logic and a sensor system - laser range finder. The navigation algorithm using a fuzzy logic is achieved by organizing the knoweledge base for self-navigation of mobile robot. In order that mobile robot is economically arrived the goal, the knowledge base is applied to acquire the informations of moving distance, direction, and velocity in every cycle time.

• Journal of the Korea Society of Computer and Information
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• v.13 no.3
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• pp.153-160
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• 2008

One of the most important features of the Mobile Manipulator is redundant freedom. Using it's redundant freedom, a Mobile Manipulator can move in various modes, and perform dexterous motions. In this paper, to improve robot job performance, two robots -mobile robot, task robot- are joined together to perform a job, we studied the optimal position and posture of a Mobile Manipulator to achieve a minimum of movement of each robot joint. Kinematics of mobile robot and task robot is solved. Using the mobility of a Mobile robot, the weight vector of robots is determined. Using the Gradient method, global motion trajectory is minimized, so the job which the Mobile Manipulator performs is optimized. The proposed algorithm is verified with PURL-II which is Mobile Manipulator combined Mobile robot and task robot, and the results are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.138.5-138
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• 2001

The autonomous robot has the ability of obstacle avoidance and target tracking with some manufactured information. In this paper, it is shown that autonomous mobile robot can avoid fixed obstacles using the map made before and the fuzzy controller is adopted with the global path planing and the local path planing when the robot navigates. With that map sensor, information will be used when an autonomous robot navigates. This paper proves that robot can navigate through optimized route and keep the stable condition.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.818-829
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• 2003

A cooperating control algorithm for two nonholonomic mobile robots is proposed. The task is composed of collision avoidance against obstacles and carrying a ladder. The front robot and the rear robot are called the leader and the follower, respectively. Each robot has a nonholonomic constraint so it cannot move in perpendicular directions. The environment is initially supposed to be unknown except target position. The torque that drives leader is determined by distance between the leader and the target position or the distance between it and the obstacles. The torque by target is attractive and the torque by obstacles is repulsive. The two mobile robots are supposed to be connected by link that can be expanded and contracted. The follower computes its torque using position and orientation information from the leader by communication. Simulation results show that the robots can drive to target position without colliding into the obstacles and maintain the distance in the allowable range.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.4
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• pp.62-67
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• 2002

This paper presents a new approach to the design of cruise control system of a mobile robot with two drive wheel. The proposed control scheme uses a Gaussian function as a unit function in the fuzzy-neural network and back propagation algorithm to train the fuzzy-neural network controller in the framework of the specialized loaming architecture. It is Proposed a learning controller consisting of two neural network-fuzzy based on independent reasoning and a connection net with fixed weights to simply the neural networks-fuzzy. The performance of the proposed controller is shown by performing the computer simulation for trajectory tucking of the speed and azimuth of a mobile robot driven by two independent wheels.