• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.208.2-212
• /
• 1997

In a model based friction comensation for a frictional system,the performance of the system is inflenceed by the selection of the friction model. Especially, when a real plant have dynamic friction characteritics, the compensation of friction with a static friction model may deteriorate the perfomance. For the system we constlucted an adaptiv parameter estimation and friction compensation with a newly introduced dynamic friction model proposed by Canudas et.[1]. The model depicts varios frictional phenomena,such as Stibeck effect,frictional memory, Stick-slip motion. Parmeter identification algorithm are followed conventional RLSM adaptive rule. The stability for the closed system was proved by the Lyapunov stability. The result say that if a real system have dynamic friction property,the friction compensation with the dynamic friction model will improve the perfomance moreover static friction model based compensation may lead to the system unstable.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권6호
• /
• pp.221-227
• /
• 2002

In this paper, the system model for the compensation of the low-cost personal navigation system is derived and the error compensation method using GPS is also proposed. WNS(Walking Navigation System) is a kind of personal navigation system using the number of a walk, stride and azimuth. Because the accuracy of these variables determines the navigation performance, computational methods have been investigated. The step is detected using the walking patterns, stride is determined by neural network and azimuth is calculated with gyro output. The neural network filters off unnecessary motions. However, the error compensation method is needed, because the error of navigation information increases with time. In this paper, the accumulated error due to the step detection error, stride error and gyro bias is compensated by the integrating with GPS. Loosely coupled Kalman filter is used for the integration of WNS and GPS. It is shown by simulation that the error is bounded even though GPS signal is blocked.

• 전기학회논문지
• /
• 제67권3호
• /
• pp.433-439
• /
• 2018

In this paper, a SDINS(strapdown inertial navigation system) rapid initial alignment technique with adaptive time delay compensation is proposed. The proposed method consists of two steps. In first step, misalignment and data latency are estimated by conducting pre-transfer alignment. Then, hybrid alignment is designed to rapidly find the misalignment changes induced by pyro-shock. To improve the performance of hybrid alignment, adaptive time delay compensation method is suggested. We verify the performance improvement of the proposed alignment scheme comparing with the conventional transfer alignment method by van test. The test result shows that the proposed alignment technique improves alignment performance.

• 대한기계학회논문집
• /
• 제18권9호
• /
• pp.2358-2367
• /
• 1994

This paper presents techniques for evaluation and compensation of total measuring errors in a commercial CMM. The probe errors as well as the machine geometric errors are assessed from probing of the mechanical artefacts such as shpere, step, and rings. For the error compensation, the integrated volumetric error equations are considered, including the probe error adn the machine geometric error. The error compensation is performed on the absolute scale coordinate system, in order to overcome the redundant degree of freedom in the CMM with multi-axis probe. A interface box and corresponding software driver are developed for data intercepting/correction between the machine controller and machine, thus the volumetric errors can be compensated in real time with minimum interference to the operating software and hardware of a commercial CMM. The developed system applied to a practical CMM installed on the shop floor, and demonstrated its performance.

• 산업융합연구
• /
• 제21권2호
• /
• pp.9-16
• /
• 2023

연구는 경영자 능력이 보상정책(보상수준 및 성과-보상 민감도)에 미치는 영향에 대해 분석하였다. 이를 위해 2012년부터 2019년까지 금융업을 제외한 코스피 및 코스닥 상장기업을 대상으로 최종 14,150 기업-연도 자료를 활용하였다. 실증분석 결과, 경영자 능력이 높을수록 차기 보상수준은 증가하지만(경영자 능력가설), 성과-보상 민감도는 감소하는 것으로 나타났다. 이는 경영자 능력과 보상 사이 양(+)의 관계를 통해 경영자 능력가설을 재확인하면서, 경영자 능력에 대한 높은 보상이 성과에 기인하기 보다는 성과 이외 경영자 능력에 대한 추가적인 보상일 수 있다는 점을 의미한다. 본 연구는 경영자 능력과 보상체계의 보다 복합적인 효과를 살펴보았다는 점에서 기존 연구와의 차별성 및 기여점을 가진다.

• 한국정밀공학회지
• /
• 제31권11호
• /
• pp.987-992
• /
• 2014

Register control of roll-to-roll printing system for printed electronics requires accurate measurement of register errors. The register marks used for the recognition of patterns position between layers have inherently defects due to low printability of register marks themselves, which brings out inaccurate register accuracy and consequently low performance of printed electronics devices. In this study, the compensation methods for the unrecognized or missing register data are proposed to improve the recognition and consequently the control performance of register accuracy in roll-to-roll printing equipment. The compensation methods using the prior data and the linear interpolation are proposed and compared with the case without compensation for the simulation as well as experiment. Only the linear interpolation method could successfully compensate the missing data and consequently improve the register control performance. We should apply the compensation process of the register errors to improve the register control accuracy in the roll-to-roll printing equipment.

• Journal of Power Electronics
• /
• 제18권5호
• /
• pp.1545-1554
• /
• 2018

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.191-194
• /
• 2001

In this paper, we propose a series active power filter control method to compensate current harmonics and unbalanced source voltage. The system is composed of series active power filter and shunt passive filer that are tuned 5th and 7th harmonics. In this conventional system, series active power filter complements drawbacks of the shunt passive filter, namely improves harmonic compensation characteristics, and compensates unbalanced source voltage. In the proposed algorithm, compensation voltage for harmonic reduction is calculated by performance function, and compensation voltage for unbalanced source voltage is calculated in based on a synchronous reference frame. So, ultimate compensation voltage is sum of those two compensation voltages. By computer simulation, we verify the excellency of proposed method.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.85-88
• /
• 2000

In this paper, the ultra precision positioning system for piezoelectric actuator using hysteresis compensation has been developed. Piezoelectric actuators exhibit limited accuracy in tracking control due to their hysteresis nonlinearity. The main purpose of the proposed controller is to compensate the hysteresis nonlinearity of the piezoelectric actuator. The controller is composed of a PD, hysteresis compensation and neural network part in parallel manner, at first, the excellent tracking performance of the neural network controller was verified by experiments and was compared with the classical PD controller.

• 한국공작기계학회논문집
• /
• 제11권5호
• /
• pp.93-99
• /
• 2002

In general, manufacturing error is originated from bad material, machine tool defection and tool breakage. When the manufacturing process is stable, the most of error come from the tool wear. In common on-machine measurement teaching probe and touch sensor are widely used however in this paper the electric touch point type automatic tool compensation system is developed the performance of it is validated and effective operating is proposed.