• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.717-719
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• 2004

Currently mobile devices change rapidly our life and they have considerable influences over many parts of our society. If the mobile device is applied to a control system, the usability of the control system is increased with its convenient accessibility and mobility. This paper realizes a motor control system by using a mobile device. The device uses Intel Xscale PXA-250 in which Widows CE is ported. The device is very popular at the applications of mobile devices. Also we consider its application to a mobile robot such as home service robot.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.82-89
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• 2015

This study proposes a new approach to design and control for autonomous mobile robots. In this paper, we describes a fuzzy logic based visual servoing system for an autonomous mobile robot. An existing system always needs to keep a moving object in overall image. This mes difficult to move the autonomous mobile robot spontaneously. In this paper we first explain an autonomous mobile robot and fuzzy logic system. And then we design a fuzzy logic based visual servoing system. We extract some features of the object from an overall image and then design a fuzzy logic system for controlling the visual servoing system to an exact position. We here introduce a shooting robot that can track an object and hit it. It is illustrated that the proposed system presents a desirable performance by a computer simulation and some experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.933-938
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• 2001

In this paper, we describe a method for the mobile robot using images of a moving object. This method combines the observed position from dead-reckoning sensors and the estimated position from the images captured by a fixed camera to localize a mobile robot. Using the a priori known path of a moving object in the world coordinates and a perspective camera model, we derive the geometric constraint equations which represent the relation between image frame coordinates for a moving object and the estimated robot`s position. Since the equations are based on the estimated position, the measurement error may exist all the time. The proposed method utilizes the error between the observed and estimated image coordinates to localize the mobile robot. The Kalman filter scheme is applied to this method. Effectiveness of the proposed method is demonstrated by the simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.6
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• pp.529-536
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• 2004

Autonomous navigation of an indoor mobile robot using the global ultrasonic system is presented in this paper. Since the trajectory error of the dead-reckoning navigation grows with time and distance, the autonomous navigation of a mobile robot requires to localize the current position of the robot, so that to compensate the trajectory error. The global ultrasonic system consisting of four ultrasonic generators fixed at a priori known positions in the work space and two receivers on the mobile robot has the similar structure with the well-known satellite GPS(Global Positioning System), and it is useful for the self-localization of an indoor mobile robot. The EKF(Extended Kalman Filter) algorithm for the self-localization is proposed and the autonomous navigation based on the self-localization is verified by experiments.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.129-138
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• 2004

In this paper, we propose a method to apply a decentralized control algorithm for passive velocity field control using virtual flywheel system to cooperative 3-wheeled mobile robots, and these subsystem are under nonholonomic constraints. The considered robotic systems convey a common rigid object in a horizontal plain. Moreover we will proof the passivity and robustness for cooperative mobile robotic systems with decentralized passive velocity field control. Finally, The effectiveness of proposed control algorithm is examined by numerical simulation for cooperation tasks with 3-wheeled mobile robot systems.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.126.3-126
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• 2001

A new method to govern the navigation of a mobile robot is proposed based on the following two procedures: one is to achieve vision information by using a 2 D-O-F camera as a communicating medium between a man and a mobile robot and the other is to analyze and to behave according to the recognized hand gesture commands. In the previous researches, mobile robots are passively to move through landmarks, beacons, etc. To incorporate various changes of situation, a new control system manages the dynamical navigation of a mobile robot. Moreover, without any generally used expensive equipments or complex algorithms for hand gesture recognition, a reliable hand gesture recognition system is efficiently implemented to convey the human commands to the mobile robot with a few constraints.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.498-505
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• 2002

Reducing odometer errors caused by kinematic imperfections in wheeled mobile robots is imestigated. Wheel diameters and wheelbase are corrected by using encoders without landmarks. A new velocity trajectory is proposed that compensates for an orientation error due to acceleration- resolution constraints on motor controllers. Based on this velocity trajectory, the wheel velocity of one out of two driven wheels may be changed by the traveled distance of the mobile robot. It is shown that a wheeled mobile robot can't move along a straight line exactly, even if kinematic correction are achieved perfectly, and this phenomenon is attributable to acceleration-resolution constraints on motor controllers. We experiment on a wheeled mobile robot with 2 d.o.f. are used in the experiment to verify the proposed scheme.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.6
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• pp.1-7
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• 2011

This paper presents implementation and control of a two wheeled mobile robot system which consists of two systems, an inverted pendulum system and a mobile robot system. Control purpose is to regulate its balancing and navigation. The balancing robot has advantages of one point turning and robust balancing against disturbances from the ground. Simulation studies of local and global control methods are performed. Since the robot is implemented to have a symmetrical structure, simple linear control algorithms are used for balancing and navigation. Low cost sensors such as gyro and tilt sensor are fused together to detect the inclined angle. Experimental studies of following desired circular trajectory are conducted.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.800-808
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• 2008

This paper presents a localization algorithm of the outdoor wheeled mobile robot using the sensor fusion method based on indirect Kalman filter(IKF). The wheeled mobile robot considered with in this paper is approximated to the two wheeled mobile robot. The mobile robot has the IMU and encoder sensor for inertia positioning system and GPS. Because the IMU and encoder sensor have bias errors, divergence of the estimated position from the measured data can occur when the mobile robot moves for a long time. Because of many natural and artificial conditions (i.e. atmosphere or GPS body itself), GPS has the maximum error about $10{\sim}20m$ when the mobile robot moves for a short time. Thus, the fusion algorithm of IMU, encoder sensor and GPS is needed. For the sensor fusion algorithm, we use IKF that estimates the errors of the position of the mobile robot. IKF proposed in this paper can be used other autonomous agents (i.e. UAV, UGV) because IKF in this paper use the position errors of the mobile robot. We can show the stability of the proposed sensor fusion method, using the fact that the covariance of error state of the IKF is bounded. To evaluate the performance of proposed algorithm, simulation and experimental results of IKF for the position(x-axis position, y-axis position, and yaw angle) of the outdoor wheeled mobile robot are presented.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1159-1168
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• 2006

In this paper, a new revolute mobile robot arm with five degree of freedom (d.o.f) was developed for autonomous moving robots. As a control system for the robot arm, a distributed control system composed of the main controller and five motor controllers for arm joints was developed. The main controller and the motor controllers w ε re developed using the ARM microprocessor and the TMS320c2407 microprocessor, respectively. A new trajectory tracking algorithm for the motor controllers was devised employing pre-generated off-line trajectory data. Also, a 3-D simulator based on the openGL software to simulate the motion of the robot arm was developed. To validate the performance of the robot system, experiments to track a specified trajectory were performed.