Kh Park

Contactless magnetically levitated silicon wafer transport system

A new magnetically levitated wafer transport system is developed for the semiconductor fabrication process to get rid of the particle and oil contaminations that normally exist in conventional transport systems. The transport system consists of levitation, stabilization tracks, and a propelling system. Stabilities needed for levitation in the transport system are achieved by an antagonistic property produced in the tracks and using a simple feedback control. The continuous propelling force is obtained by sending specific current patterns to the propulsion coils. The dynamic model of the transport system is presented and analyzed.

Wafer distribution system for a clean room using a novel magnetic suspension technique

A linear transport system, which is capable of reducing the weight of a moving carrier by separating power-supplying devices, is developed by using a new magnetic levitation technique. This system is designed to distribute a wafer between semiconductor fabrication process modules in clean rooms, because it can eliminate particles and oil contamination that normally exist in conventional transporter systems due to rubbing of mechanical components. The transport system consists of a wafer carrier, two levitation tracks, two stabilization tracks, and a propelling system. Levitation is achieved by using opposing forces produced between electromagnet tracks and permanent magnets. Stabilization is achieved by using a simple feedback control. The continuous propelling force is obtained by sending specific current patterns to the propulsion coils. The dynamic model of the transport system is presented, and it is verified by experiment. The system performance is experimentally investigated.

Emotion Interaction System for a Service Robot

This paper introduces an emotion interaction system for a service robot. The purpose of emotion interaction systems in service robots is to make people feel that the robot is not a mere machine, but reliable living assistant in the home. The emotion interaction system is composed of the emotion recognition, generation, and expression systems. A users emotion is recognized by multi-modality, such as voice, dialogue, and touch. The robots emotion is generated according to a psychological theory about emotion: OCC (Ortony, Clore, and Collins) model, which focuses on the users emotional state and the information about environment and the robot itself. The generated emotion is expressed by facial expression, gesture, and the musical sound of the robot. Because the proposed system is composed of all the three components that are necessary for a full emotional interaction cycle, it can be implemented in the real robot system and be tested. Even though the multi- modality in emotion recognition and expression is still in its rudimentary stages, the proposed system is shown to be extremely useful in service robot applications. Furthermore, the proposed framework can be a cornerstone for the design of emotion interaction and generation systems for robots.

High speed micro positioning system based on coarse/fine pair control

A coarse/fine pair control system is suggested to relieve the difficulty of obtaining high accuracy over a large movement. A coarse actuator which is capable of high force in a large working range is developed using electromagnetic principle. A fine actuator having a high accuracy is introduced using a piezoeletric material. The coarse/fine actuator pair system is applied to magneto-optical (MO) disk drives to enhance the systems performance in terms of speed and accuracy.

Force control for magnetic levitation system using flux density measurement

This paper demonstrates theoretically and experimentally the idea of magnetic force control in magnetic levitation systems using flux density measurements. A Hall-effect sensor is used to sense the flux density in the airgap. The magnetic force is obtained by its proportional relation to the flux density. A simple magnetic levitation system which consists of a U-shaped electromagnet and a manipulator is used. First, the system dynamics are described in state space form using airgap displacement, velocity of the magnetically levitated manipulator, and the flux density as state variables. Second, the magnetic levitation system is stabilized using digital state feedback control. The magnetic force is then regulated using a digital H/sub /spl infin// controller to achieve robust stability, disturbance/noise rejection and asymptotic tracking. Simulation and experimental results in terms of speed and accuracy are presented.

A high speed tracking system using adaptive model-following control

In the time optimal control problem, it is important to select a switching point accurately in order to improve tracking speed performance. However, the accurate selection of the switching point is not an easy task because of the damping coefficient variations and modeling uncertainties in actual systems. To relieve the difficulty and inconvenience of this task, adaptive model-following control (AMFC) is implemented. AMFC can make the controlled plant follow as closely as possible a desired reference model whose switching point can be calculated easily and accurately, assuring that the error between the reference model and the real system approaches zero. The AMFC is applied for a tracking actuator of a magneto-optical disk drive (MODD) to improve its slow tracking performance. According to the simulation and experimental results, an average tracking time as small as 20 ms is obtained for a 3.5 in. magneto-optical disk drive.

Emotional Exchange of a Socially Interactive Robot

This paper presents an emotional exchange framework for a socially interactive robot. The purpose of emotional exchange in social interaction between a robot and people is to make people feel that the robot is a believable living assistant, not a mere machine for information translation. Our emotional exchange framework is composed of the emotion recognition, generation, and expression systems. A users emotion is recognized by multi-modality such as voice, dialogue, and touch. The robots emotion is generated according to a psychological theory about cognitive emotions caused by the social interaction within people. Furthermore, the emotion intensity is regulated by the loyalty level of a robot to various users. The generated emotion is dynamically expressed by facial expression, gesture, and the musical sound of the robot. The proposed system, which is composed of all the three components that are necessary for a full emotional interaction cycle, is implemented in the real robot system and tested. The proposed framework can be a cornerstone for the design of emotion interaction and generation systems for robots.

Coarse/Fine Pair Control System for Magneto-optical Disk Drives

To relieve the difficulty in having high accuracy over a large movement, a coarse/fine pair control system is introduced. A coarse actuator which is capable of high force in a large working range is developed using electromagnetic principle. A fine actuator having a high accuracy is developed using a piezoeletric material. The coarse/fine actuator pair system is applied to magneto-optical (MO) disk drives to enhance the systems performance in terms of speed and accuracy.