Jihong Lee

3D Shape Restoration System for Femto-Second Laser Processing Utilizing Image Obtained by Line Scan Laser

In this paper, we consider a femtosecond laser processing system for ITO glass. To maximally deliver the laser energy, i.e., to focus the laser on the ITO glass, we propose a 3D shape restoration system for error compensation. The shape restoration system utilizes line laser and 2D profile image from the acquired profiles of the ITO glass. The proposed system is composed of line laser, high resolution camera, linear motion platform synchronized to image capturing, and control station. The results of the proposed system are compared with the results of SPM (scanning probe microscope) and prove the usefulness of the system

Real-time remote monitoring system based on personal communication service (PCS)

Instead of an RF module which has been used conventionally in many remote measurement applications, a new type of remote measurement system for oceanic environments based on a PCS and a one chip microcontroller is proposed. PCS has many advantages with respect to cost, reliability, communication quality, and so on. The proposed system consists of four different modules: PCS module, microcontroller module, GPS module, and sensor module. System configuration as well as an illustrative experiment are described in detail.

Dynamic Manipulability for Cooperating Multiple Robot Systems with Frictional Contacts

This paper presents a strategy for finding feasible acceleration range, i.e., dynamic manipulability, of multiple robotic systems with frictional contacts between robot end-effectors and object. The frictional contact conditions are generally described by Coulombs Law which requires each contact force to lie within a friction cone. Since the friction cones are described by nonlinear inequality constraints, it is not easy to handle the constraint in manipulability analysis. To include the frictional contact condition into the conventional manipulability, we approximate the friction cone to a pyramid which is described by linear inequality constraints. And then achievable acceleration boundaries of manipulated object are calculated by conventional linear programming technique under constraints for torque capability of each robot and the approximated contact condition. With the proposed method we find some solution to which conventional approaches did not reach. Also, case studies will be presented to illustrate the correctness of the proposed approach for two robot systems of simple planar robots and PUMA560 robots

Development of a remote controlled mobile entertainment robot system

Deals with the design and implementation of a remote controlled mobile entertainment robot. The developed system is intended to be used in advertising, amusement and sales-promotion. The system must be able to attract peoples attention. Therefore our system has the ability to move around a two-dimensional floor with wheels and control every multimedia file format including MPEG files, WAVE files, MP3 files, and so on. In the paper, the structure of the overall robot system as well as the details for each part such as motion controller, multimedia controller, wireless communication systems, and motor driving circuits, are described.

Operating a six-legged outdoor patrol robot

In this paper we present the mechanical/electrical design of half-sized outdoor patrol robot CALEB I. The robots are designed to be operated by both remote control mode and autonomous mode. To patrol around buildings efficiently and safely, we implemented navigation algorithms based on GPS and odometer, and obstacle avoidance and traversal as well as posture stabilization. The robot offers autonomous surveillance for outdoor environments, which is proved by a set of experiments in outdoor environment.

Estimation of Friction Coefficient for Exploring Robot around Rough-Terrain under Small-Slip or Less-Traction Condition

One of the important factors for the exploration robot to travel in diverse environments is estimation of friction coefficient on the ground. Algorithm for estimating friction coefficient based on the Traction-Slip Curve developed in the previous research is a method for estimating friction coefficient when there is slip generated while the robot is driving. However, in many cases, sufficient slip does not occur in the real environment. In this paper, we divided into 4 cases according to the slip ratio and traction. In the case of low slip occurrence, we modified the algorithm to estimate the friction coefficient on the low slip area based on the previously estimated ground information. And we show the result of estimation of friction coefficient under the condition of low slip through the simulation based on the proposed method.

Hardware design and swimming strategy for stable pitch motion of underwater robot: CALEB10

The CALEB10 is an underwater robot that can swim and walk in underwater environment. In this paper, we propose a hardware design and a swimming control method to stabilize unstable pitch motion during swimming in neutral buoyancy state where CALEB10 is completely immersed in water. And the idea of this study are verified by a dynamics-based simulator and underwater experiment.

Modified watershed algorithm considering zero-crossing point of gradient

In this paper, we propose a modified watershed algorithm considering zero-point of gradient to obtain a correct edge of a region. The conventional watershed algorithm decide priority considering gradient of a region to be extended. However if the grey levels of two neighboring seeds are quite different, the ridge line obtained by the conventional watershed algorithm is not coincided with the correct edge. It is probable that the point where gray level extreme value occurs will be estimated as an edge of two neighboring regions. Therefore more correct edge of a region can be obtained if the expansion of watershed algorithm is delayed where the extreme value occurs. The position where the gray level extreme value occurs corresponds to the position where the zero-crossing of gradient occurs. So we adjust the priority to postpone expansion at the zero-crossing point of gradient. We compare the proposed method with the conventional method and validate that this proposed method can extract more correct edge of a region.