Myung-Jin Jung

A High Performance Controller for NAND Flash-based Solid State Disk (NSSD)

NAND flash memory based solid-state disk (NSSD) has been used for industrial and military use due to its high reliability and shock resistance. With the bit cost reduction of flash memory and the explosive growth of flash market, NSSD is expected to penetrate into diverse applications such as mobile thin clients, car navigation systems and movie players, which prefer low power consumption, high reliability, high performance and so on. This paper mainly focuses on the development of a high performance and cost-efficient controller for NSSD, with the aim of describing both hardware and software architectures. In order to demonstrate the usefulness of the proposed approach, we show performance, power consumption and start-up time evaluation results over magnetic disks using third party benchmark tools

A cooperative multi-agent system and its real time application to robot soccer

The soccer robot system consists of multi agents, with highly coordinated operation and movements so as to fulfill specific objectives, even under adverse situation. The coordination of the multi-agents is associated with a lot of supplementary work in advance. The associated issues are the position correction, prevention of communication congestion, local information sensing in addition to the need for imitating the human-like decision making. A control structure for a soccer robot is designed and several behaviors and actions for a soccer robot are proposed. Modified zone defense as a basic strategy and several special strategies for fouls are applied to SOTY and MIRO teams for MIROSOT (Micro-Robot World Cup Soccer Tournament).

Facial expressive robotic head system for human-robot communication and its application in home environment

This paper describes a robotic-head system as a multimodal communication device for human-robot interaction, and the systems potential application in home environments. Most robotic systems for natural user interaction have facial expressions, since facial expressiveness is regarded as a key component to developing personal attachment along with prosodic expressiveness. In the first part of the paper is the description of our robotic head system Character Robot Face (CRF). A deformation approach and a parametric normalization scheme are proposed to produce facial expressions of nonhuman face models with high recognition rates. In the second half of the paper, CRF is endowed with artificial emotions and assigned tasks conceivable in home environments. A coordination mechanism between the robots mood (an activated emotion) and its task is proposed so that the robot can, by referring to the emotion-task history, select a task depending on its current mood if there is no explicit task command from the user. When the robot performs a task, a particular emotion value gets boosted according to the same emotion-task history so that the emotion is more likely to be activated.

A Hybrid Control Structure for Vision Based Soccer Robot System

ABSTRACTA soccer robot system consists of multi-agents with highly coordinated operations and movements so as to fulfill specific objectives, even under adverse situations. The coordination of multi-agents is associated with lot of supplementary work in advance. The associated issues are position correction, prevention of communication congestion, local information sensing in addition to the need for imitating human-like decision making. A hybrid control structure for vision-based soccer robot system is designed and several behaviors and actions for a soccer robot system are proposed. The hybrid control scheme has hierarchical and behavioral structures. The effectiveness of the proposed structure is validated by implementing the same in a real soccer robot system. Variable zone defense as a basic strategy, formation strategies and set-position play strategies for fouls applied to SOTY II team during MiroSot are discussed.

The miniature omni-directional mobile robot OmniKity-I (OK-I)

The structure of OmniKity-I (OK-I), the miniature omni-directional mobile robot, and its kinematics and dynamics models are presented. OK-I has three DOFs in the plane. A conventional two wheeled mobile robot (2-WMR) serves as the base of OK-I for translational motion. The robot body is on top of the base. The third motor controls angular motion of the body as the base turns according to the translational motion. The circular surface connector (CSC) is devised to transfer signals from the base to the body without constraining angular motion of the body. Experimental results show proper omni-directional features of OK-I.

Structured light 2D range finder for simultaneous localization and map-building (SLAM) in home environments

Map building and localization of mobile robots is one of the keys to implementing autonomous navigation systems. Owing to the many efforts in the past decade it has proved that map building and localization simultaneously (SLAM, simultaneous localization and map-building) is possible both theoretically and practically. Features or landmarks obtained from sensor measurements are registered and associated in SLAM if they are sustainable and correctly matched ones. To have such features it is essential to use a sensor system that provides precise range measurements. Typical sensors for SLAM are such as laser range finder (LIDAR) or ultrasonic sensors. LIDARs provide very accurate and long range measurements while measurements from ultrasonic sensors are shorter and coarse due to cone shaped beam patterns. In this paper we propose a SLAM system using a structured light sensor to SLAM in home environment. The accuracy is less than that of LIDAR (10 cm at 3 meters), but measurements are very dense laterally so that a small corners, often existing in home environments, can be determined as feature points in 3 meters. We introduce the implemented system for home use and prove its efficacy by showing the SLAM experimental results.

Fault tolerant control strategy for OmniKity-III

In this paper a novel wheeled omnidirectional mobile robot, the OmniKity-III (OK-III), is developed and its kinematic model and control laws are derived. A special gear train with omnidirectional mechanism was developed using conventional tire wheels. Several control laws are provided by considering the robot as a redundantly actuated wheeled mobile robot on the plane. Since the robot has three degrees of freedom in motion, failure in any one of the motor can be compensated by the other two motors in posture control although the omnidirectional mobility is lost. Simulations and experiments demonstrate the effectiveness of the proposed omnidirectional mechanism.

Mobility augmentation of conventional wheeled bases for omnidirectional motion

Presents the mobility augmentation method to provide omnidirectional mobility to nonomnidirectional wheeled bases. First, the kinematic model of a nonomnidirectional wheeled base and a link combined by an extra revolute/prismatic joint to the base is derived in a matrix-vector form. Then it is shown that, if the kinematic model satisfies some structural conditions, the link motion can be omnidirectional. The structural conditions for omnidirectional motion are derived and several examples are provided to demonstrate the method.

Action selection and strategies in robot soccer systems

The robots used in MiroSot (Micro-Robot World Cup Soccer Tournament) are small in size (7.5cm/spl times/75cm/spl times/7.5cm), fully/semi autonomous and without any human operators. MiroSot involves multiple robots that need to collaborate in an adversarial environment to achieve specific objectives. They have dynamic environments as other robots intentionally affect the environment in unpredictable ways. The key aspect being the need for robots not only to control themselves, but also to track and control the ball which is a passive part of the environment. In multi-robot systems the environments dynamics can be determined by other robots in addition to the uncertainty that may be inherent in the domain. The interesting theoretical issue behind MiroSot experiments is the use of soccer as a prototype example of a complex, adaptive system. And let us inculcate sports robotship in our soccer robots.

Autonomous Micro-Robot 'Kity' for Maze Contest

A table-look-up immune network is proposed to solve problems arising from autonomous microrobots trying to achieve a given goal with limited memory and calculation capacity. The method is implemented and tested with a microrobot “Kity”, with a size of less than 1 cubic inch. It is possible to generate enough rules to make the robot achieve the goal of navigating freely in a maze with a small number of sensors. Experimental results show the efficacy of immune networks in controling robots in restricted environments. Kity demonstrated the efficiency of the associated algorithm arrived at by winning first prize at the 4th and 5th International Microrobot Maze Contests held in Nagoya, Japan, in October, 1995 and 1996.