Deokhwa Hong

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A major problem of optical microscopes is their small depth-of-field (DOF), which hinders automation of micro object manipulation using visual feedback. Wavefront coding, a well-known method for extending DOF, is not suitable for direct application to micro object manipulation systems based on visual feedback owing to its expensive computational cost and(More)
Automatic optical inspection (AOI) for printed circuit board (PCB) assembly plays a very important role in modern electronics manufacturing industries. Well-developed inspection machines in each assembly process are required to ensure the manufacturing quality of the electronics products. However, generally almost all AOI machines are based on 2D(More)
In this paper, fusion of visual and inertial information is proposed for attitude measurement of remotely-operated mobile robots. The primary objective is to eliminate the drift error of the inertial sensors using visual information for exact and fast sensing of attitude. By this fusion each output is not only combined together but also helps the other(More)
Insufficient vision information such as occlusion and low resolvability is one of the important issues that limit the micromanipulation and microassembly. In this paper, we proposed the active vision system that can interact with the environment by changing optical system parameters such as spatial position, orientation and focus plane. As an(More)
Proportional control based visual controller is the main method used in the visual serving, but small proportional gain results in the slowly response and large proportional gain will result in large overshoot or make the system instable. A PD visual controller for microassembly system is presented to acquire better dynamic response. The fuzzy logic is(More)
In this paper, the variable view imaging system (VVIS) developed to offer flexibility in microscopic observation is applied to microassembly tasks to overcome several problems in normal imaging systems that hindered application of vision-guided micromanipulation techniques such as limited field of view (FOV) and fixed viewing direction. In three(More)
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