• Journal of Institute of Control, Robotics and Systems
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• v.11 no.9
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• pp.761-767
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• 2005

There exists a structural limit of 2WS cars that drivers would not like simultaneously to follow the desired path and attenuate moments resulting from disturbances because lateral acceleration and yaw rate are coupled inherently. In order to overcome the limit, the 4WS cars that have rear wheel steering as an additional input have been introduced. But the 4WS cars have disadvantages that much cost is required due to structural alteration, it is difficult to be used to the driving circumstances and tire performances are not efficient in nonlinear or large lateral acceleration ranges. Therefore, it is proposed that, in this paper, a robust controller is easy to apply to 2WS cars by using direct yaw moment, decouples lateral acceleration from yaw motion and is robust against disturbances and uncertainties of system parameters, and thus the proposed control method has the advantages of 4WS cars which can be achieved in 2WS cars.

• Journal of the Ergonomics Society of Korea
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• v.18 no.2
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• pp.57-69
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• 1999

The primary objective of this research was to suggest the design dimensions of automotive seating package that has an important effect upon seating package design. To conduct the research, a set of manikin dimensions that are representative for Korean was determined by using a statistical scheme. With these dimensions, we generated nine manikins for male and female, respectively. Also, the preferred driving posture was investigated using the experimental setup. To find each joint angle for subjects, a driving monitoring system was developed and a three dimensional motion analysis system was employed. The joint angle for the subject was established and compared with related literature. With the generated manikins and each joint angle, the driving posture was simulated by using SAFEWORK that is a program to generate manikins. The positions and adjustable ranges from the accelerator heel point to the hip point and the steering wheel center point that are important variables in order to design seating package were suggested. Further research is needed to determine the seating package dimensions three dimensionally.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.528-531
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• 1997

This paper deals with the kinematic and dynamic modeling of a 3 degree-of-freedom redundantly actuated mobile robot for the purpose of analysis and control. Each wheel is driven by two motors for steering and driving. Therefore, the system becomes force-redundant since the number of input variable is greater than the number of output variable. The kinematic and dynamic models in terms of three independent joint variables are derived. Also, a load distribution method to determine the input loads is introduced. Finally we demonstrate the feasibility of the proposed algorithms through simulation.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.69-70
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• 2013

By using differential force between left and right wheel, lateral motion can be controlled known as Direct Yaw-moment Control (DYC). In previous researches, DYC control is proposed to increase the stability of the vehicle, but maneuverability has not been discussed sufficiently. The car handling condition which is called the index parameter of maneuverability is dependent on the vehicle velocity and steering angle. To achieve the desired vehicle's cornering path, the car handling condition must be considered sufficiently. In this paper, the novel DYC method is proposed which gives the car handling condition regardless of the longitudinal speed. The proposed controller is based on the PI controller to feedback the curvature parameter. The controlled system shows the advantages of DYC regarding to the reference trajectory by the dual motor system. With respect to the uncontrolled model, the effectiveness of the proposed method is validated by numerical examples.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.741-745
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• 2001

Reliability and safety of steer-by-wire concepts can be achieved by redundant designs. This paper discusses the design of a fault tolerant concept for a force feedback actuator with a standard three-phase PMSM. In contrast to usual drives, the phases of the machine are separated electrically. This design allows driving the machine with two instead of three phases in case of a fault. A superimposed torque controller adjusts the influence of fault currents and torque harmonics in two-phase operation and guarantees smooth torque at the steering wheel

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.1-11
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• 1998

The 4WS system is usually developed to improve the maneuverability at low speed and the straight line stability at high speed, but it is found to have the severe understeer characteristics at high speed. Therefore a 4WS vehicle requires to turn the steering wheel much more than a 2WS vehicle at high speeds even a driver goes through the same curved road. In this study, to enhance the cornering performance of the 4WS vehicle at high speed, a DYC 4WS system is proposed based on the nonlinear 4WS system and direct yaw moment control system. Especially the proposed DYC 4WS system is able to realize a zero side slip angle for vehicles and a cornering performance similar to the 2WS vehicle at high speed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.690-697
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• 2000

The objective of this study is to develop a method that is able to realize autonomous traveling for tractor-like robot on the slope terrain. A neural network (NN) and genetic algorithms (GAs) have been used for resolving nonlinear problems in this system. The NN is applied to create a vehicle simulator that is capable to describe the motion of the tractor robot on the slope, while it is impossible by the common dynamics way. Using this vehicle simulator, a control law optimized by GAs was established and installed in the computer to control the steering wheel of tractor robot. The autonomous traveling carried out on a 14-degree slope had initial successful results.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.20-26
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• 1997

A System for reducing vehicle body roll by active control is developed. The stabilizer bar with hydraulic rotary actuator produces anti-roll moment which suppresses roll tendency. This reduction of roll improves the driving safety as well as the ride comfort. Vehicle test data shows considerable reduction of roll angle during steady-state turning. Also improvement of ride comfort is achieved by making the actuator freely rotatable, i.e. by connecting all chambers of actuator in normal driving conditions. A control algorithm using steering wheel angle and vehicle speed signal as input valve is applied. It is compared with signal of the G-sensor.

• Proceedings of the Safety Management and Science Conference
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• 2001.05a
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• pp.325-329
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• 2001

This paper deals with a newly developed direction indicator system of a car which displays left turn and U- turn signal differently, so that the following driver can identify the Intent of the next car ahead easily. In general, when a car want to change its direction, the driver move the blinker lever below the steering wheel up or down. However, as the left turn and U-turn signal are the same, there always be the risk of rear-end collision by misinterpreting U-turn signal as left turn signal. In this paper, a new direction indicator system which differentiates left turn and U-turn signal is developed. The left turn signal is the same as before, but when a driver want to U-turn, an additional U-turn signal blinks at the rear of the car. By identifying the direction signals clearly, the developed system is expected to alleviate the risk of car accident.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.2
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• pp.13-19
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• 1986

The purpose of this paper is to develop a 3-dimensional human model, an ergonomic CAD (Computer-Aided Design) system which would be very helphul in ergonomic design. An interactive program was developed, in which a user could change layout, body size, skin volume, and posture of the human model. As an example, effect of inclination of a steering wheel on visibility of a display panel was demonstrated. he result showed that ergonomic design can be aided by the 3-dimensional human model, and by the perspective graph by which design and evaluation process can be carried out more effectively.