• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.5
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• pp.480-489
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• 1999

Design and experimental results of yaw rate controller is described for electricallydriven four wheel vehicle without steering mechanism. Yaw rate controller has been known to be necessary to cope with nonlinear char-acteristics of the wheel/road conditions with respect to different road condition and steering angle. For an effective yaw rate control, a fuzzy PID gain scheduler is considered with changing control parameters. In order to apply proposed algorithm to the system a downsized four wheel drive electrically driven vehicle without steering mechanism was manufactured. With these techniques the proposed yaw rate controller is shown by experiment results to be obtained suficient performance in the whole steering regions.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.46-46
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• 2000

A quadruped monitoring robot is introduced. The robot has several features that poses arbitrary position thanks to a 4-wheel hive mechanism, transmits an image and command data via RF wireless communication, and moreover, the imaged date are transferred through a network communication. The robot plays a role in monitoring what is happening around the robot and covers wide range due to a moving camera operated by the 4-wheel mechanism. The robot system can be applied k versatile models based the distinguished techniques introduced in this paper

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.285-286
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.223-224
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1469-1472
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• 2006

This paper presents experimental analysis of a friction-driven wheel responsible for generating wheel squeal. Squeal noise generating mechanism has been examined under the laboratory condition. Model rig of the rail and the wheel are made and influential parameters to squeal noise e. g. frictional force, normal force between the rail and the wheel, creep speed of the wheel have been measured and calculated. Negative damping characteristic curve are calculated currently. Necessary relating computational analysis has been carried on also.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.8
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• pp.1298-1310
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• 1997

In recent years, grinding techniques for precision machining of brittle materials used in electric, optical and magnetic parts have been improved by using superabrasive wheel and precision grinding machine. The completion of optimum dressing of superabrasive wheel makes possible the effective precision grinding of brittle materials. However, the present dressing system cannot have control of optimum dressing of the superabrasive wheel. In this study, a new system and the grinding mechanism of optimum in-process electrolytic dressing were proposed. This system can carry out optimum in-process dressing of superabrasive wheel, and give very effective control according to unstable current and gap increase. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of brittle materials.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.3
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• pp.329-334
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• 2008

It is well-known that a kind of wheel drive mechanism is usefully employed in various service robots. One of the essential requirements for such robots is regarded as the capability of climbing that enables them to run on an inclined road smoothly. So, this paper considers the capability of climbing in a wheel drive robotic mechanism and proposes a necessary discriminating condition to determine the specification of a driving actuator which will be employed. Consequently, it is expected that the proposed discriminating condition can be applied to wheel drive robotic mechanisms in the design aspect.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.132-138
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• 2006

A tape feeder is an important part to supply a micro chip such as 1005 and 0603 components in SMT process. Traditional sprocket wheel type feeder has several problems such as backlash and indexing errors, low compatibility and confidence. However, it is very difficult to solve such problems due to the inevitable fraction defectives of sprocket wheel. Thus, the object of this works is to develop a linear type high precision tape feeding system using cam-slider mechanism. The proposed cam-slider mechanism is composed of several links and a plate, pneumatic actuator is used to generate linear motion. The proposed mechanism has distinct advantages over the conventional mechanism. It has reduced feeding errors, long lift-cycle, and slim width. As a result, the developed tape feeder using cam-slider mechanism shows special characteristics far high precision feeding for chip-mounters.

• Tribology and Lubricants
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• v.13 no.2
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• pp.68-73
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• 1997

The adhesion between wheel and rail plays an important role in the braking performance of trains. Though there have been numerous studies on the characteristics of adhesion phenomenon, a general understanding from the physical point of view is still lacking. In this work, the adhesion mechanism between wheel and rail was investigated by studying the mechanisms of pure rolling and sliding experiments. Tests were performed under various conditions to determine the physical phenomenon responsible for adhesion between wheel and rail. The results of this study is expected to aid in improving the braking performance of trains.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.203-210
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• 2011

This study formulates the theoretical wheel-set model to evaluate wheel-climbing derailments of rolling stock due to collision, and verifies this theory with dynamic simulations. The impact forces occurring during collision are transmitted from a car body to axles through suspensions. As a result of combinations of horizontal and vertical forces applied to axles, rolling stock may lead to derailment. The derailment type will depend on the combinations of the horizontal and vertical forces, flange angle and friction coefficient. According to collision conditions, the wheel-lift, wheel-climbing or roll-over derailments can occur between wheel and rail. In this theoretical derailment model of wheelset, the wheel-climbing derailment types are classified into Climb-over, Climb/roll-over, and pure Roll-over according to derailment mechanism between wheel and rail, and we proposed the theoretical conditions to generate each derailment mechanism. The theoretical wheel-set model was verified by dynamic simulations.