• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.133-138
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• 1993

This paper presents neural network based position estimation method in slippery environment as an approach to solve one of problems which are engaged in dead reckoning method. Position estimator is composed of slip detector and linear velocity estimator. Both of them are based on the fact that dynamic characteristic of mobile robot in slippery environment is different from the case without slip. To find out the dynamic relation among driving torque, angular acceleration of driving wheel and linear acceleration of mobile robot, accelerometer is used for measuring acceleration of mobile robot and neural network is used for dynamic system identifier in slippery environment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.320.1-320
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• 2002

In a hard disk drive (HDD) control system, a state-space controller/observer design is popularly adopted fur its advantages such as effective filtering of position and velocity, use of estimation error to handle servo defects, etc. In this report, a systematic method is proposed to accommodate the transport delay in the plant dynamics into the state estimator. (omitted)

• 한국자동차공학회논문집
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• 제10권6호
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• pp.234-240
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• 2002

This paper treats the problem of estimating the longitudinal velocity of a braking vehicle using measurements from an accelerometer and wheel speed data from standard anti-lock braking wheel speed sensors. We develop and experimentally test three velocity estimation algorithms of increasing complexity. The algorithm that works the best gives peak errors of less than 3 percent even when the accelerometer signal is significantly biased.

• 대한기계학회논문집
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• 제16권6호
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• pp.1036-1055
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• 1992

본 연구에서는 일단앞섬 상태추정기(one-step ahead state estimator)를 사용 하는 방법을 제안하였다. 이 방법은 비선형 시스템을 궤환 선형화하여 등가 선형모 델을 구한 후, 이 등가 선형 모델에 일단앞섬 상태추정기를 구성하여 디지틀 제어를 실현하는 방법으로서, 계측할 수 없는 상태를 추정할 수 있을 뿐 아니라, 선형시스템 에 대한 상태 추정기이므로 다음 단계의 상태를 비교적 정확하게 추정할 수 있어서 궤 환 선형화시 요구되는 연속적인 상태 궤환에 근사시킬 수 있고, 직접 궤환 선형화된 등가 선형 모델의 상태를 추정할 수 있으므로, 변환시의 연산량도 줄일 수 있다. 이 로서 Grizzle이나 Lee의 방법보다 간단하게 궤환 선형화에 의한 디지틀 상태 제어기를 구현할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2526-2531
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• 2005

A practical pinch torque estimator based on the Kalman filter is proposed for low-cost anti-pinch window control systems. To obtain the accurate angular velocity from Hall-effect sensor measurements, the angular velocity calculation algorithm is executed with additional procedures for removing the measurement noises. Apart from the previous works using the angular velocity estimates and torque estimates for detecting the pinched condition, the torque rate is augmented to the system model and the proposed pinch estimator is derived by applying the steady-state Kalman filter recursion to the model. The motivation of this approach comes from the idea that the bias errors in torque estimates due to the motor parameter uncertainties can be almost eliminated by introducing the torque rate state. For detecting the pinched condition, a systematic way to determine the threshold level of the torque rate estimates is also suggested via the deterministic estimation error analysis. Simulation results are given to certify the pinch detection performance of the proposed algorithm and its robustness against the motor parameter uncertainties.

• 제어로봇시스템학회논문지
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• 제13권11호
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• pp.1053-1059
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• 2007

This paper presents a target sate estimator(TSE) with low pass filter for improving the gun driving command. The ballistic computer uses target information such as predicted range, velocity, acceleration of a target to generate the gun command. We adopt the finite impulse response(FIR) filter as our TSE to shorten calculation time for the driving command and due to its inherent stability property. We also introduce a post-processing filter to reduce the high frequency components in the output signal of a TSE which may cause instability of gun driving. The first order low pass filter has been designed based on $H{\infty}$ criteria considering the noise characteristics. To show the validity of the present scheme, simulation results are given for the overall gun driving system including aircraft target information.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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• pp.350-355
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• 1997

The problem of mathematical model for an unknown system by measureing its input-output data pairs is generally referred to as state estimates. The state estimation problem is often of importance in its own right since we may want to know the value of the states. For instance, in navigation, we may take noisy positional fixes using satelite or radar navigation, and the estimator can use these measurements to provide accurate estimates of current position, hedaing, and velocity. And the state estimates can also be used for control purposes. Then it is very important to know the state of plant. In this paper, the theory of the minimization of a loss function was used to design the fuzzy system. Here, the used teory is Least Square Esimation method. This parametrization has the Linear in the parameters charcteristic that allows standard parameter estimation technique to be used to estimate the parameters of the fuzzy system. The combination of the fuzzy system and the estimation m thod then performs as a nonlinear estimator. If several fuzzy label are defined for the input variables at the antecedent part, the fuzzy system then behaves as a collection of nonlinear estimators where different regions of rules have different parameters. In simulation results, the fuzzy model controlled a difference in the structure between the actual plant and the fuzzy estimator. It is also proved that the fuzzy system is equivalent to its transformed system. therefore we was able to get the state space equation of system with the estimated paramater.

• 한국정밀공학회지
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• 제20권3호
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• pp.58-65
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• 2003

Vehicle acceleration data from an accelerometer and wheel speed data from standard, 50-tooth antilock braking system wheel speed sensors are used to estimate the absolute longitudinal speed of a vehicle. We develop the four velocity estimation algorithms. And we compare experimental results with the Butterworth filtered speed from the fifth wheel and find that it is possible to estimate absolute longitudinal vehicle speed during a hard braking maneuver lasting three seconds.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.713-714
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• 2013

• 천문학회보
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• 제44권2호
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• pp.70.3-70.3
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• 2019

We present a method to estimate 3-component plasma velocity (Vx, Vy and Vz) at solar photosphere near solar disk center, using the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) called Space-weather HMI Active Region Patch (SHARP). In Heliocentric-Cartesian Coordinates, the component of Vz is obtained from Dopplergram while the components of Vx and Vy are derived from the relation of $B_z{\overrightarrow{u}}=B_z{\overrightarrow{{\nu}_t}}-{\nu}_z{\overrightarrow{B_t}}$ (Demoulin & Berger 2003) using a series of vector magnetograms by an optical flow technique NAVE (Nonlinear Affine Velocity Estimator). This velocity measurement method is applied to AR 12158 producing an X1.6 flare along with a coronal mass ejection. We find noticeable upflow motions at both ends of flux ropes which become a major eruption part, and strong transverse motions nearby them before the eruption. We will discuss the change of plasma motions and magnetic fields before and after the eruption.