• 한국자동차공학회논문집
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• 제12권4호
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• pp.139-145
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• 2004

This paper presents human-in-the-loop evaluations of vehicle stability control(VSC) system using a driving simulator. A driving simulator which contains full vehicle nonlinear model is evaluated by using actual vehicle test data on the same driving conditions. Braking control inputs for Vehicle Stability Control system have been directly derived from the sliding control law based on vehicle planar motion equations with differential braking. Closed-loop simulation results at realistic driving situations have shown that the proposed controller reduces driving effort of a driver and enhances stability of a vehicle.

• 한국자동차공학회논문집
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• 제24권3호
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• pp.265-272
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• 2016

The objective of vehicle aerodynamic design is on the fuel economy, reduction of the harmful emission, minimizing the vibration and noise and the driving stability of the vehicle. Especially for a sedan, the driving stability of the vehicle is the main concern of the aerodynamic design of the vehicle indeed. In this theoretical study, an evaluation algorithm of aerodynamic driving stability of a vehicle was made to estimate the dynamic stability of a vehicle at the given driving condition on a road. For the stability evaluation of a driving vehicle, CFD simulation was conducted to have the rolling, pitching and yawing moments of a model vehicle and compared the values of the moments to the resistance moments. From the case study, it is found that a model sedan running at 100 km/h in speed on a straight level road is stable under the side wind with 45 m/s in speed. But the different results may be obtained on the buses and trucks because those vehicles have the wide side area. From the case study of the model vehicle moving on 100 km/h speed with 15 m/s side wind is evaluated using the numerical algorithm drawn from the study, the value of yawing moment is $608.6N{\cdot}m$, rolling moment $-641N{\cdot}m$ and pitching moment $3.9N{\cdot}m$. These values are smaller than each value of rotational resistance moment the model vehicle has, and therefore, the model vehicle's driving stability is guaranteed when driving 100 km/h with 15 m/s side wind.

• International Journal of Automotive Technology
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• 제5권2호
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• pp.109-114
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• 2004

This paper presents a closed-loop evaluation of the Vehicle Stability Control (VSC) system using a vehicle simulator. Human driver-VSC interactions have been investigated under realistic operating conditions in the laboratory. Braking control inputs for vehicle stability enhancement have been directly derived from the sliding control law based on vehicle planar motion equations with differential braking. A driving simulator has been validated using actual vehicle driving test data. Real-time human-in-the loop simulation results in realistic driving situations have shown that the proposed controller reduces driving effort and enhances vehicle stability.

• International Journal of Automotive Technology
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• 제7권7호
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• pp.813-819
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• 2006

As the vehicle becomes bigger and faster, the importance of vehicle stability in an extreme driving condition caused by sudden steering, road condition or unexpected case has been emphasized. The ESP system is being utilized to improve the handling performance and the vehicle stability. In this study, we implemented various tests and proposed estimation methods for ESP characteristics in extreme driving situations. The estimation methods for ESP proposed in this paper are expected to facilitate developing the control logic and improving the performance of the ESP system.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.393-398
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• 2006

This paper classifies driving technologies for AMOLEDs by the driving TFT conditions in pixels. A saturation region operation type driving TFT circuit provides good stability of OLED because of constant current drive. However, complicated compensation circuits are necessary to avoid effect of the TFT characteristics deviation. On the other hand, a linear region operation type driving TFT circuit provides better uniformity of the display image and lower power consumption. However, the stability of OLED is critical because of constant voltage drive.

• 제어로봇시스템학회논문지
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• 제22권11호
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• pp.919-924
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• 2016

This paper proposes a robust control design method for improving the cornering stability of a personal electric vehicle equipped with in-wheel motors. In general, vehicles undergo severe parameter variations and unpredictable disturbances with respect to a wide range of driving conditions (e.g., road surface conditions and vehicle velocity conditions). For this reason, robust control design techniques are required to guarantee consistent driving performances and robustness against various driving conditions. In this paper, an adaptive sliding mode control method is employed to enhance cornering stability by controlling the direct-drive in-wheel motors independently. Additionally, in order to confirm the effectiveness of a proposed control method, real driving tests with an experimental personal electric vehicle are performed.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.543-554
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• 1995

본 논문에서는 전동화 수동 휠체어 INMEL-VII를 위한 주행 안정성과 제어기의 개선에 관하여 연구하였다. 기 개발된 INMEL-VI의 2년 여에 걸친 현장 실험에서 오르막길에서의 후방 전복으로 인한 주행안정성, 모터의 PWM 제어로 인한 스위칭 노이즈, 심한 내리막길에서 주행 명령이 없어도 모터가 회전하는 문제들이 지적되었다. 이러한 문제를 해결하기 위해 INMEL-VII에서는 모터와 구동축을 직결하고 출력을 증가시켰으며 바퀴의 중심축을 이동하여 무게중심을 안쪽으로 이동시켜서 후방 전복 임계 경사각을 크게 증가시켰고, 스위칭 주파수를 5kHz로 설정하기 위해 하드웨어를 개선하였다. 또한 INMEL-VII에서는 다양한 가속 및 감속 루틴으로 소프트웨어의도 개선하였다. 현장 주행 실험 결과 기계적 구성과 소프트웨어의 개선으로 인한 주행 안정성이 증가되고 다양한 조작이 가능해졌음을 알 수 있었다. 본 연구결과로 장애자의 보행 보조기구연구에 기여하고 보행부자유자에게는 염가의 국산 전동휠체어를 사용할 수 있는 기화가 증가되기를 기대한다.

• 한국소음진동공학회논문집
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• 제22권7호
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• pp.650-658
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• 2012

This paper proposes a high performance position controller for a driving system using a time optimal controller which has been widely used to control driving systems to achieve desired reference position or velocity in a minimum response time. The main purpose of this research lies in an improvement of transient response performance rather than that of steady-state response in comparison with other control strategies. In order to refine the scheme of time optimal control, Lyapunov stability proofs are incorporated in a controller of standard second order system model. This scheme is applied to the control of a driving system. In view of the simulation and experiment results, the standard second order system model exhibits better minimum-time control performance and robustness than double integral system model does.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.2213-2214
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• 2011

It is important to consider power stability in case of design and construction of a substation at railroad because a train is operated by electricity and tains are drived simultaneous at the same section. This paper described stability of feeder system considering driving conditions and railroad conditions of train which is drived. Simulation tool, TOM(Train Operations Model) software is used to ensure stability of feeder system. As results of simulation, feeder voltage source is in limits on driving operation dia of trains.

• 로봇학회논문지
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• 제9권2호
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• pp.124-131
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• 2014

The robot mechanisms that were previously researched had only been conducted for the purpose of overcoming the obstacles stably at low speed driving and enhancing the stability against high speed circuitous driving, and yet, the mechanism satisfying two purposes. However, in order to stably drive with high speed on rough terrain, there is a need for satisfying both of these purposes, as well as testing the efficiency of the mechanisms at high speed driving. There, this paper simulated some of the passive mechanisms and focused on checking the performances of passive mechanisms through simulations and analyzing each mechanism on the basis of an evaluation index. The simulation was conducted by Adams (The Multi-body Dynamics Simulation Solution) and used various types of passive mechanisms which were introduced in the robotics field. As a result, the study confirmed that passive mechanisms have a number of situations that affect the driving stability on each direction of roll and pitch. Further study is needed about active mechanism.