• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.479-479
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• 2000

Recently, IVS(Intelligent Vehicle Systems) or ITS(Intelligent Traffic Systems) are much concerned subjects of automotive industry. In this paper, we will introduce an Intelligent Online Driving System for a car. This system allows the driver to be able to drive the car just by operating an integrated joystick. The proposed driving system could be implemented into any car and the key point of the design is that the driver still can drive the car as normal without using the joystick. Our Intelligent Online Driving System includes the integrated joystick, steering wheel control system, brake and acceleration (B&A)pedals control system, and the central control computer system. Steering wheel and B&A pedals are controlled by AC servo-motors. The integrated joystick generates the desired positions and the embedded computer controls these two servomotors to track the commands given by joystick. The control method for two servo-motors is PID control.

• Tribology and Lubricants
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• 제23권5호
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• pp.228-233
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• 2007

This paper presents the case studies on the friction related wears of an automotive tire, which is strongly connected to the safety and comfort of a driver during a running of a car. Wear scars of a tire tread are affected by various causes such as an air pressure, a wheel alignment, a driving speed, road conditions, starting and braking habits of a driver. The data were collected from used tires for a replacement at the car service center. Most of the wear problems came from the improper repair and adjustment of revolving components, which cause an unbalanced wear of a tread part of a tire. Thus, the regular checking of a tire radically reduces the wear scars of a tire and may increase a driving safety and a fuel economy of a car and a wear life of a tire.

• 항공우주시스템공학회지
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• 제10권1호
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• pp.95-102
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• 2016

There are many possible disturbance sources on such a spacecraft, but reaction wheel assembly (RWA) which is generally used for spacecraft attitude control is anticipated to be the largest. These effects on degradation of performance of spacecraft such as attitude stability. In reaction wheel, disturbance caused by imbalance and speed error. It is hard to emulate speed error disturbance because it is not coincide with wheel frequency. This paper concentrates on emulating and analyzing the speed error disturbance. Firstly, classify the causes that lead to speed error disturbance which generate RPM fluctuation. Secondly, simulated with disturbance driver module and reaction wheel assembly which are developed by Spacecraft Control Lab. Experimental investigations have been carried out to test the disturbance emulator module as a disturbance generator for RWA. Measurements and test have been conducted on various fault. Frequency analysis of test data show that speed error disturbance effects on wheel settling wheel speed or fluctuation type.

• 자동차안전학회지
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• 제11권2호
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• pp.23-28
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• 2019

This paper presents an optimal performance of rear wheel steering vehicle for maneuverability. The maneuverability of vehicle is evaluated in terms of yaw rate, body slip angle and driver input. The maneuverability of vehicle can be improved by rear wheel steering system. To obtain optimal performance of rear wheel steering vehicle, the optimal control history is designed. The high dimensional trajectory optimization problem is solved by formulating a quadratic program considering rear wheel steer input. To evaluate handling performance 7 degree-of-freedom vehicle model with actuation sub-models is designed. A step steer test is conducted to evaluate rear wheel steering vehicle. A response time, a TB factor, overshoot, and yaw rate gain are investigated through objective criteria, assessment webs. The handling performance of vehicle is evaluated via computer simulations. It has been shown from simulation studies that optimal controlled rear wheel steering vehicle provides improved performance compared to others.

• 대한인간공학회지
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• 제29권1호
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• pp.33-37
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• 2010

This study was aimed at developing 1) iso-perception maps for various groups of drivers in terms of age, gender, and anthropometry and 2) the experiment framework required for obtaining subjective and objective measures. A total of 9 maps, which describe drivers' perceptions regarding their static behaviors inside a typical mid-size sedan, can be used to improve the utilization of the limited driver workspace, and to select better design alternatives for occupant packaging. An adjustable seating buck, $a^{***}$-camera motion capture system (Vicon), and $a^{**}$-channel EMG system were used for the experiment. Each iso-perception map was developed while H-PT, steering wheel center, or TGS knob center was moved to each of pre-defined positions relative to driver-selected positions. Adjustable ranges or positions of the seat, steering wheel, and TGS lever described in iso-perception maps can be used to determine better package layout alternatives.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.12-18
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• 2009

Skid mark and coefficient of friction are usually utilized to calculate the velocity and behavior of vehicles. For a critical case such as traffic accident reconstruction, however, the initial velocity of the car should be calculated precisely. In this study, in order to estimate the speed at the brake onset, rapid braking tests were executed on the proving ground. We compared with a skid length and wheel locking time of an expert driver and a general person. We verified that the skid mark of expert driver occurs longer than general person's. A new method is proposed to determine the speed of a vehicle at the brake onset of maximum braking, which could be applied to a reconstruction of vehicle with Non-ABS.

• Journal of Power Electronics
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• 제13권4호
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• pp.536-545
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• 2013

In this study, an integrated motor control algorithm for an in-wheel electric vehicle is suggested. It consists of slip control that controls the in-wheel motor torque using the road friction coefficient and slip ratio; yaw rate control that controls the in-wheel motor torque according to the road friction coefficient and the yaw rate error; and velocity control that controls the vehicle velocity by a weight factor based on the road friction coefficient and the yaw rate error. A co-simulator was developed, which combined the vehicle performance simulator based on MATLAB/Simulink and the vehicle model of CarSim. Based on the co-simulator, a human-in-the-loop simulation environment was constructed, in which a driver can directly control the steering wheel, the accelerator pedal, and the brake pedal in real time. The performance of the integrated motor control algorithm for the in-wheel electric vehicle was evaluated through human-in-the-loop simulations.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.1-7
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• 2010

Recently, the vehicle driving device has been designed for driver's convenience. Especially, the automobile industry develops the vehicle using the joystick instead of steering wheel from the concept car. The biggest strength of using the joystick is that the driver feels less workload and fatigue than when the driver uses steering wheel. However, this kind of study still needs more research and experiments for more accurate result. Therefore, this research evaluated workload according to the driving device by the survey and the measurement of physiological signal. The reason not only using the survey also using the measurement of physiological signal is to support the result of the survey which is not enough to bring the accurate result. There were tow different kinds of methods to carry out this research; SWAT (Subjective Workload Assessment Technique) for the survey and the biopac equipment for the measurement of physiological signal. Furthermore, previously established driving simulator, GPS (Global Positioning System), and Seoul-Cheonan virtual expressway DB were used for the experiment. As the result of the experiment with 13 subjects, it was certain that using joystick device brings less workload and fatigue to the drivers than using steering wheel following both methods-the survey and the measurement of physiological signal. Also, it confirmed the significant result from the SPSS (Statistical Package for the Social Sciences) statistics analysis program.

• 대한기계학회논문집A
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• 제30권12호
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• pp.1551-1556
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• 2006

Two yaw motion control systems that improve a vehicle lateral stability are proposed in this study: a rear wheel steering yaw motion controller (SESP) and an enhanced rear wheel steering yaw motion controller (ESESP). A SESP controls the rear wheels, while an ESESP steers the rear wheels and front outer wheel to allow the yaw rate to track the reference yaw rate. A 15 degree-of-freedom vehicle model, simplified steering system model, and driver model are used to evaluate the proposed SESP and ESESP. A robust anti-lock braking system (ABS) controller is also designed and developed. The performance of the SESP and ESESP are evaluated under various road conditions and driving inputs. They reduce the slip angle when braking and steering inputs are applied simultaneously, thereby increasing the controllability and stability of the vehicle on slippery roads.

• International Journal of Automotive Technology
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• 제5권2호
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• pp.95-108
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• 2004

Lanekeeping assistance has the potential to save thousands of lives every year by preventing accidental road departure. This paper presents experimental validation of a potential field lanekeeping assistance system with quantitative performance guarantees. The lanekeeping system is implemented on a 1997 Corvette modified for steer-by-wire capability. With no mechanical connection between the hand wheel and road wheels the lanekeeping system can add steering inputs independently from the driver. Implementation of the lanekeeping system uses a novel combination of a multi-antenna Global Positioning System (GPS) and precision road maps. Preliminary experimental data shows that this control scheme performs extremely well for driver assistance and closely matches simulation results, verifying previous theoretical guarantees for safety. These results also motivate future work which will focus on interaction with the driver.