• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.162.3-162
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• 2001

The essence of ABS(Anti-skid Brake System) control is to continuously adjust brake pressure to maintain optimum brake torque. This optimum level should balance tire and runway friction its peak value, yielding maximum braking deceleration. It influences not only the deceleration and the taxing distance of an aircraft, but also the strength and the fatigue life of the landing gear. In this paper, an ABS control algorithm is developed with a dynamics model of 5-DOFD(Degree of Freedom). The algorithm is verified by simulations and the simulation results are presented. The dynamics model is simulated by the computer.

• 한국군사과학기술학회지
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• 제16권3호
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• pp.240-249
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• 2013

This paper discusses the maneuvering control algorithm based on all-wheel independent driving and steering control techniques for special purpose 6WD/WS vehicles. The maneuvering control algorithms considering superior dynamic characteristics of high power in-wheel motors and independent steering system are designed to perform driving, steering, vehicle stability, and fault tolerant control. The maneuvering controller applies sliding and optimal control theories considering optimal torque distribution and friction circle related to the vertical tire force. The fault tolerant control algorithm is applied to obtain the similar maneuverability to that of the non-faulty vehicle. The simulations using the Matlab/Simulink dynamics model and experiments using HIL simulator mounting the real controllers with the designed control algorithms prove the improved performances in terms of vehicle stability and maneuverability.

• 제어로봇시스템학회논문지
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• 제8권3호
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• pp.199-207
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• 2002

In this paper, a self-tuning gain-scheduled skyhook control for semi-active suspension systems is investigated. The dynamic characteristics of a continuously variable damper including electro-hydraulic pressure control valves is analyzed. A 2-d.o.f. time-varying quarter-car model that permits variations in sprung mass and suspension spring coefficient is considered. The self-tuning skyhook control algorithm proposed in this paper requires only the measurement of body acceleration. The absolute velocity of the sprung mass and the relative velocity of the suspension deflection are estimated by using integral filters. The skyhook gains are gain-scheduled in such a way that the body acceleration and the dynamic tire force are optimized. An ECU prototype is discussed. Experimental results using a 1/4-ear simulator are discussed. Also, a suspension ECU prototype targeting real implementation is provided.

• International Journal of Automotive Technology
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• 제8권2호
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• pp.211-217
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• 2007

The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional ABS (Anti-lock Brake System) systems. In realizing the wheel slip control systems, real-time information such as the tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance and stability enhancement. In this paper, a robust wheel slip controller is developed based on the adaptive sliding mode control method and an optimal target slip assignment algorithm is proposed for maximizing the braking force. An adaptive law is formulated to estimate the braking force in real-time. The wheel slip controller is designed based on the Lyapunov stability theory considering the error bounds in estimating the braking force and the brake disk-pad friction coefficient. The target slip assignment algorithm searches for the optimal target slip value based on the estimated braking force. The performance of the proposed wheel slip control system is verified in HILS (Hardware-In-the-Loop Simulator) experiments and demonstrates the effectiveness of the wheel slip control in various road conditions.

• 한국산림과학회지
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• 제95권3호
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• pp.350-357
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• 2006

인공강우발생장치를 이용하여 산불발생지를 대상으로 산불발생 후 경과년수에 따라 각 지역에 대한 강우강도 및 경사별로 지표유출량을 관측하여 산불발생지의 지표유출 특성을 구명하고, 또한 지표유출량과 강우강도, 경사, 경과년수와의 관계를 분석하였으며, 그 결과는 다음과 같다. 1. 산불발생연도별 지표유출량은 강우강도가 30 mm/hr씩 증가함에 따라서 2.2~3.2배 증가하였으며, 경사가 $10^{\circ}$씩 증가함에 따라서는 1.5~1.9배 증가하였다 2. 산불발생지에서 지피식생이 80% 이상 피복되더라도 초기강우 때의 지표유출량은 다소 많이 발생하여, 식생에 의한 유출량 감소효과는 높지 않았다. 3. 산불발생 후 경과년수에 따라 강우강도 및 경사별로 구분한 지표유출량은 산불발생 3년 후의 경우 발생당년에 비해 22.3%~41.8%로 감소하였고, 산불발생당년에는 강우강도 및 경사별로 지표유출량에 많은 차이가 있었으나 시간이 경과할수록 그 차이가 작아졌다. 4. 산불발생지사변에서의 지표유출량에 대해 각 인자간의 영향성을 분석한 결과, 강우강도, 경사, 경과년수의 각각의 주효과와 강우강도${\times}$경사, 강우강도${\times}$경과년수의 상호작용 효과에 대해서는 차이를 보였고, 경사${\times}$경과년수, 강우강도${\times}$경사${\times}$경과년수의 상호작용 효과에 대해서는 차이가 없었다. 지표유출량에 영향을 미치는 인자의 영향도는 강우강도가 가장 큰 영향을 미치고 다음이 경사, 경과년수의 순이었다.