• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.5
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• pp.559-566
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• 2016

This study shows a development procedure and results of noise reduction for a new developed FF 8th speed automatic transmission. Based on planetary gear operating frequency analysis using PTA(planetary transmission analysis) program developed in 2012, It is expected that gear noise of the rear planetary gear set could be recognized easily in the concept design stage. Therefore, pRMC (planetary run many cases) analysis program that is developed in 2012 was applied to minimize the planetary gear noise level and noise distributions versus torque. To minimize noises coming from oil pump and final gears of a new transmission, several changes were applied, such as changing the clearance of double angular ball bearing, the oil pump rotor tooth number from 9 to 11 and the oil pump type from parachoid to megafloid and so on. Besides, stiffness values of the transmission case and the mount bracket were measured and reinforced properly. Finally, The total noise of the new FF 8th speed automatic transmission was developed successfully. Furthermore, E.O.L. testers also have been adapted to control the noise quality of automatic transmission assembly in the manufacturing factory. This paper could provide practical solutions to the automatic transmission NVH problems.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.97-100
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• 1998

In this paper, micro step driving method is used for the high performance motion control and low vibration and low noise in an X-Y axis soldering machine for factory automation. The improvement of the electrical and mechanical driving characteristic of a stepping motor is achieved by applying microstep driver.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.11
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• pp.1393-1404
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• 1995

For the factory automation(FA) of production or assembly lines, computer vision techniques have been widely used for the recognition and position-control of objects. In this application, it is very important to analyze characteristic features of each object and to find an efficient matching algorithm using the selected features. If the object has regular or homogeneous patterns, the problem is relatively simple. However, If the object is shifted or rotated, and if the depth of the input visual system is not fixed, the problem becomes very complicated. Also, in order to understand and recognize objects with concentric noise patterns, it is more effective to use feature-information represented in polar coordinates than in cartesian coordinates. In this paper, an algorithm for the recognition of objects with concentric circular noise-patterns is proposed. And position-conrtol information is calculated with the matching result. First, a filtering algorithm for eliminating concentric noise patterns is proposed to obtain concentric-feature patterns. Then a shift, rotation and scale invariant alogrithm is proposed for the recognition and position-control of objects uusing invariant feature information. Experimental results indicate the effectiveness of the proposed alogrithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.441-443
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• 2022

Currently, image processing is being used in various fields such as image analysis, image recognition, and factory automation according to the development of IT technology. Salt and pepper noise is generated due to various external factors in the process of acquiring or transmitting an image, which deteriorates the image quality. Therefore, noise removal to improve image quality is essential. Various methods have been proposed to remove salt and pepper noise, and representative examples include AF, MF, and A-TMF. However, the conventional filter has insufficient noise removal performance in a high-density noise environment. Therefore, in this paper, we propose an algorithm for estimating and processing the original pixel by using the modified distance weight filter only in the case of noise, and replacing the original pixel in case of non-noise after performing noise judgment. To evaluate the performance of the proposed algorithm, we compare and analyze it with existing algorithms using PSNR.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.835-839
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• 2004

For factory automation using force/torque control, we need a networked-force management system as well as good force sensing and force generation. In this paper, we present a web-based force management system including 6-axis force/torque sensing system. Performance of the force-torque sensor is affected significantly by analog noise that is included in a sensor signal, and the noise should be reduced appropriately to obtain an adequate performance of the sensor. Moreover, the sensor itself should be convenient to install to a real application system. It should be compact in size and also easy to wire in real situation. In this viewpoint, we developed usb-based compact sensor system which is well communicated using web between two computers that exist far away. Software is programmed using LabVIEW and CCS-C. PIC microcontrollers are used for implementing a compact hardware. The proposed system is verified through experimental works.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.1
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• pp.56-65
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• 2011

A new hybrid mount system is proposed for microvibration control in a high-tech factory. The mount consists of an airspring as a passive device and a piezostack actuator as an active device. The two devices are connected in series. Some numerical simulations and experimental tests are carried out to evaluate isolation performance of the mount system comprising of four proposed hybrid mounts. As a control logic, the specific algorithm is adopted for considering multiple target frequencies of excitation based on a Filtered-X LMS algorithm. The results are compared with isolation performance of the passive airspring mount system. It is confirmed that the proposed hybrid mount system has great performance on microvibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.187-193
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• 1998

In the tandom pencil slat saw lines, feeding of cedar blocks is often stopped because excessive motor current is required in a saw machine. These events are called "kickoffs' in factory lines. Kickoffs decrease productivity due to machine down-time and damage to saw blades often accompanies them. Researches on saw behavior at kickoff are required to understand and reduce the frequency and severity of kickoff events. This research aims at understanding the fundamental mechanisms of kickoffs during cutting, predicting the impending kickoff and evolving design improvements for high cutting performance with fewer and less severe kickoffs.offs.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.58-61
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• 1994

본 연구에서는 내부 외부 진동원(8-30Hz)에 따른 격자보 구조의 동적 응답을 효과적으로 제어하기 위해 격자보 구조의 동적 거동에 지배적인 영향을 미치는 철근비, 질량, 탄성계수 등 여러 인자들의 비교, 분석을 통해 동적 거동에 영향을 미치는 인자를 분석함으로써 격자보 구조의 설계시 인자의 변화에 따른 동적 거동 특성을 예측하여 이에 적절히 대응할 수 있도록 도모하였다. 이를 위해 국내에 건설된 반도체 공장의 격자보 구조 중에서 기본 해석 모델을 결정하고 이에 대해 실험적 모드 해석과 유한 요소 해석을 사용해서 기본 해석 모델의 모드 매개변수를 구하고, 기본 해석 모델에 사용되는 각 인자가 고유 진동수에 미치는 영향을 비교.분석하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.90-95
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• 2008

Medium and high speed marine diesel engines have been widely used as prime mover in small car ferries and fishing vessels with reduction gear. These propulsion shafting system should be installed and matched the elastic coupling between engine and reduction gear to isolate the vibratory torque. In this paper, the elastic dynamic characteristics of coupling with rubber type circular segments is confirmed by the theoretical analysis using the FEM and the hydraulic exciting test at shop. And its adaptation is investigated in the torsional vibration test in factory shop.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.994-999
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• 2008

The necessity of diagnosis of the rotating machinery which is widely used in the industry is increasing. Because vibration diagnosis can avoid sudden breakdown of machine and reduce the maintenance costs. In the factory, Air-Compressor which can affect the performance and capacity of output is important machine. Therefore, in this paper, The measuring and analyzing is carried out for air-compressor in order to the factor of resonance and resonance avoidance for air-compressor. The result of diagnosis and solution is discussed in this paper.