Transfer robots for large-sized panels used in the display industry need to compensate for path error and reduce vibration. The iterative learning control (ILC) technique can simply compensate for the uncertainty of a control system in a repetitive motion. This study introduces an ILC compensation system applied with an accelerometer to a display panel transfer robot control system. The ILC technique was used to reduce the path error and vibration induced the flexibility of the large size robot. This method was applied to a robot system without the system model of the mechanical and measurement elements. To improve the iterative learning performance through the accelerometer, the ILC is configured by applying an acceleration element and time shift method to the PD-Offline ILC algorithm. In addition, based on the characteristics of repetitive motion, the ILC derives an acceleration data-based position estimation value. In this study, the ILC system and a large-sized panel transfer robot were implemented in MATLAB-Simulink with RECURDYN. The path errors and vibration level of the robot with a suggested ILC of 20 repeated learnings were reduced by more than 90%.

Electroadhesion has many advantages over other adhesion methods such as pneumatic, hydraulic, magnet, etc. The applications include electrostatic chucks and grippers. Recently, electroadhesion has been adopted for robots working in limited environments. The electro-adhesive climbing robots can be used for inspection and exploration in a variety of conditions. The electroadhesion robots often have a limited adhesion force. In this paper, we propose a novel pad structure improving the adhesion force. An additional insulating layer prevents the discharge from the high voltage application and increases the adhesion force per unit area. The electroadhesion forces were compared for the different pad materials and electrode structures and were partly confirmed as the theoretical model. The proposed pad was used for a climbing robot wheel. The climbing robot weighs approximately 3 kg and can manage to 3 kg of extra weight on metal walls. Experiments showed a 90-degree gradability for the climbing robot.

Recently, instrument stages using flexure guide mechanisms and piezo actuators have been widely used for an ultra-precision positioning system in various industries. Research into ultra-precision position control aiming at nanoscale position errors during stage driving is being actively conducted, as well as various studies on the motion profile adjusting the reference input. In this study, we suggested a motion profile with snap and feedforward for use with a high speed nano scanning system, as compared and analyzed with the position tracking error through feedback control, and also compared to the related feed with the forward control noted as minimized at the position error to 14.19 nm. As a result, a tracking error when applying the fourth profile with snaps to the piezoelectric stage, is obtained with an error reduction effect of about 15%, as compared to when the second profile is applied.

This paper presents a development process of an advertising accessory including a light guide to be applied to mobile devices. At first, this research is to design an optical part as a light guide to transmit the light more than 10% of the LED light from mobile devices. Secondly, it presents the mechanical design of the part to be applicable to size changes of mobile devices and to enduring external forces. By using ANSYS and OPTISWORKS, a preliminary design including to tune the applied material properties is performed to prevent from the failure of the component, to maintain the proper pressure for holding mobile devices with different thickness, and to obtain enough optical transmission efficiency. In addition, this paper introduces a manufacturing process for the advertising accessory with a chemical and mechanical polishing. In order to measure the performance of the manufactured accessory, here, measurement devices such as measuring the pressing force, luminance, and illuminance are also designed and fabricated. Several modifications are made for the purpose of improving the measured performance.

The demand for inspection of high-speed systems for machined Carbon Fiber Reinforced Plastics parts for automobileindustry and aviation industry is constantly rising. One of the factors that degrade the performance of an inspection system is micro-vibration from the ground or structure where is placed. Various isolation systems that suppress the vibration have been studied classified as either passive or active system. The passive system is composed of a spring and a damper while the active system suppresses the vibration through an electronic control system using sensors and actuators. In this study, a voice coil motor (force constant 55N/A) acting as the actuator is optimally designed using permeance method and sequential quadratic programming algorithm to suppress the vibration and reaction force by a specimen moving stage. The two optimized voice coil motors are attached to a pneumatic mount that has an advantage in design based on the force and size constraints required by the user for an active vibration isolator with velocity sensors (GS-11d). The active vibration isolation system with the four active vibration isolators -23 dB and -20 dB at resonance frequencies in horizontal and vertical transmissibility performs better than a passive vibration isolation system.

A high precision air bearing stage has been developed and calibrated. This linear-motor driven stage was designed to transport a glass or wafer with the X and Y following errors in nanometer regime. To achieve this level of precision, bar type mirrors were adopted for real time ΔX and ΔY laser measurement and feedback control. With the laser wavelength variation and instability being kept minimized through strict environment control, the orthogonality of this type of control system becomes purely dependent upon the surface flatness, distortion, and assembly of the bar mirrors. Compensations for the bar mirror distortions and assembly have been performed using the self-calibration method. As a result, the orthogonality error of the stage was successfully decreased from 0.04° to 2.48 arcsec.

Recently, with rapid development of semiconductor and flat panel display, the manufacturing equipments are required to have large travel range, high productivity, and high accuracy. In this paper, an ultra precision decoupled dual servo (DDS) system is proposed to meet these requirements. And a control scheme for the DDS is studied. The proposed DDS consists of a XYθ fine stage for handling work-pieces precisely and a XY coarse stage for large travel range. The fine stage consists of four voice coil motors (VCM) and air bearing guides. The coarse stage consists of linear motors and air bearing guides. The DDS is mechanically decoupled between coarse stage and fine stage. Therefore, both stages must be controlled independently and the performance of the DDS is mainly determined by the fine stage. For high performance tracking, the controller of fine stage consists of time delay control (TDC) and perturbation observer while the controller of coarse stage is TDC alone. With these individual controllers, two kinds of dual-servo control strategies are suggested: master-slave type and parallel type. By simulations and experiments, the performances of two dual-servo control strategies are compared.