• 대한전자공학회논문지SD
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• 제49권5호
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• pp.37-42
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• 2012

기존의 전류 스티어링 전하 펌프의 타이밍 부정합 감소를 위한 새로운 전하 펌프를 제안한다. 기존의 전류 스티어링 전하 펌프는 UP, DOWN 신호의 입력단에 NMOS를 사용하여 서로 다른 지연단 수를 갖게 된다. 제안한 전하 펌프에서는 DOWN 신호의 입력단에 PMOS를 사용함으로써 UP, DOWN 신호의 지연단 수를 동등하게 한다. 기존의 전류 스티어링 전하 펌프를 최적화하여 시뮬레이션한 결과 턴온과 턴오프에 대하여 지연시간의 차이는 각각 14ns, 6ns 이다. 반면에 제안한 전하 펌프는 타이밍 부정합이 향상되어 턴온과 턴오프에 대하여 지연시간의 차이는 각각 6ns, 5ns 이다. 타이밍 부정합의 감소로 인하여 기준 스퍼는 -26dBc에서 -39dBc로 줄어들었다. 제안하는 전하 펌프는 CMOS $0.18{\mu}m$ 공정을 사용하여 설계하였다. 측정 결과 전하 펌프 출력 전압 범위 0.3~1.5V에서 최대 1.5%의 전류 부정합을 보인다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.127-130
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• 2001

In this paper, we describes a method of estimating traveling direction of a autonomous vehicle. For the development of autonomous vehicle, it is important to detect road lane and to reckon traveling direction. The object of a propose algorithm is to perform lane detection in real-time for standalone vision system. And we calculate efficent traveling direction to find steering angie for lateral control system. Therefore autonomous vehicle go forward the center of lane by adjusting the current steering angle using traveling direction.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.797-800
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• 2005

In this paper, the designed 10-bit current steering data driving circuit consists of bias circuits, shift registers, data and line latches, level shifters, and 10-bit D/A converters. This data driving circuit can improve image quality, driving speed, and can reduce process error, DNL error, and glitch noise. To reduce current cells, the 10-bit D/A converter was designed 3+3+4 hybrid type. As a result 49 current cells are decreased. The transient analysis shows that currents flows a few of mA in data line and the currents have 1024 gray levels of current values. Total circuits are designed for 10 ${\mu}s$ speed. Thus the designed 10-bit current steering data driving circuit can be usable in HDTV/XGA AMOLED displays. These data driving circuits are designed for 0.35 ${\mu}m$ CMOS process at 3.3 V and 18 V supply voltage and simulated with HSPICE..

• 한국자동차공학회논문집
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• 제5권5호
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• pp.123-131
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• 1997

To ensure drive's field of view, obstruction area generated by a steering wheel, hub and spoke must be considered at the early stage of automobile design. The current approach to computing obstruction area proposed by SAE is based on 2D drafting procedures so that it is not precise and errorprone. In the paper we discuss the novel approach which models the obstruction area as the shadows of the steering wheel, hub and spoke by assuming the human eye as light sources. The approach is based on ray tracing and space transformations for that it can be applied when free form curves are hired to represent the steering wheel, hub and spoke in CAD environment. As a result, it gives more predise and reliable results than SAE approach.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.160.3-160
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• 2001

The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A new control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder though the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.787-792
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• 1991

This paper proposes a steering control algorithm for non-holonomic mobile robots. The steering control algorithm is essential to navigate autonomous vehicles which employ comination of the dead reckoning and absolute sensor system such as a machine vison for detecting landmarks in order to estimate the current location of the mobile robot. The proposed algorithm is based on the minimum time BANG-BANG controller and curvature-continuity curve design method. In the BANG-BANG control scheme we introduce velocity/acceleration limiter to avoid any slippage of driving wheels. The proposed scheme is robot-independent and hence can be applied to various kinds of mobile robot or vehicles. To show the effectness of the proposed control algorithm, a series of computer simulations were conducted for two-wheel driven mobile robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.257-257
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• 2000

The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A predictive control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder though the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in forward and backward direction in such a way to satisfy the given constraint condition, maintain consistency, reduce the uncertainties, and guarantee robustness. A series of experiments was conducted to evaluate the control performance, in which a car Like robot was utilized to quit unwanted safety problem. As the results, the robot was keeping very well a given lane with arbitrary shape at moderate speed.

• 제어로봇시스템학회논문지
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• 제21권3호
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• pp.199-209
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• 2015

This paper presents a model predictive control (MPC) approach to control the steering angle in an autonomous vehicle. In designing a highly automated driving control algorithm, one of the research issues is to cope with probable risky situations for enhancement of safety. While human drivers maneuver the vehicle, they determine the appropriate steering angle and acceleration based on the predictable trajectories of surrounding vehicles. Likewise, it is required that the automated driving control algorithm should determine the desired steering angle and acceleration with the consideration of not only the current states of surrounding vehicles but also their predictable behaviors. Then, in order to guarantee safety to the possible change of traffic situation surrounding the subject vehicle during a finite time-horizon, we define a safe driving envelope with the consideration of probable risky behaviors among the predicted probable behaviors of surrounding vehicles over a finite prediction horizon. For the control of the vehicle while satisfying the safe driving envelope and system constraints over a finite prediction horizon, a MPC approach is used in this research. At each time step, MPC based controller computes the desired steering angle to keep the subject vehicle in the safe driving envelope over a finite prediction horizon. Simulation and experimental tests show the effectiveness of the proposed algorithm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1832-1835
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• 2005

This paper presents the steering control algorithm of an up and down motion robot using a quaternion. The up and down motion robot is to be moved on an irregular floor that can inevitably result in the errors of both position and orientation. Especially the orientation error should be compensated every work in order to adjust the misaligned values of current orientation to those commanded values. In this paper, we propose a new steering control algorithm between the two values by using a quaternion with spherical cubic interpolation. The proposed algorithm is shown to be effective in terms of vibration when compared to a conventional simple compensation without interpolation, by using $MATLAB^{(R)}$ and $VisualNastran4D^{(R)}$

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.465-466
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• 2006

In this paper, novel analog duty cycle corrector (DCC) with a digital duty error detector is proposed. The digital duty error detector measures the duty error of the clock and converts it into a digital code. This digital code is then used to accurately correct the duty ratio by adaptively steering the charge-pump current. The proposed duty cycle corrector was implemented using an 80nm DRAM process with 1.8V supply voltage. The simulation result shows that the proposed duty cycle corrector improves the settling time up to $70{\sim}80%$ at 500MHz clock frequency for the same duty correction accuracy as the conventional analog DCC.