• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.162-167
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• 2004

In this research the Co-simulation technique for an electric power steering system with MATLAB/SIMULINK and a full vehicle model with ADAMS has been developed. The dynamic responses of vehicle chassis and steering system are evaluated. Then, a full vehicle model interacted with EPS control is concurrently simulated with an impulsive steering wheel torque input to analyze the stability of 'free control' or hands free motion for Sports Utility Vehicle. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• Smart Structures and Systems
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• v.24 no.1
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• pp.141-155
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• 2019

This work evaluates the influence of negative stiffness on the performances of various vehicle suspension systems, and proposes a re-centering negative stiffness device (NSD). The re-centering NSD consists of a passive magnetic negative stiffness spring and a positioning shaft with a re-centering function. The former produces negative stiffness control forces, and the latter prevents the amplification of static spring deflection. The numerical simulations reveal that negative stiffness can improve the ride comfort of a vehicle without affecting its road holding abilities for either passive or semi-active suspension systems. In general, the improvement degree of ride comfort increases as negative stiffness increases. For passive suspension system, negative stiffness brings in negative stiffness feature in the control forces, which is helpful for the ride comfort of a vehicle. For semi-active suspensions, negative stiffness can alleviate the impact of clipped damping in semi-active dampers, and thus the ride comfort of a vehicle can be improved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.666-672
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• 2003

This paper presents a design of the controller for vehicle lateral dynamics using active yaw moment. Vehicle lateral motion is incorporated with directional controllability and stability. These are conflicting each other from the view of vehicle handling performance. To compromise the trade-off between these two aspects, we suggest a new control algorithm based on the sliding mode with time-varying switching surface according to the body side slip angle. The controller can deal with the nonlinear region in vehicle driving condition and be robust to the parameter uncertainties in the plant model. Control performance is evaluated from the simulation for the vehicle of real parameters on the road with various tire-road frictions.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1399-1410
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• 2003

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.72-80
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• 2006

Electric Power Steering (EPS) mechanism has become widely equipped in passenger vehicle due to the increasing environmental concerns and higher fuel efficiency. This paper describes the development of concurrent simulation technique and simulation integration technique of EPS control system with a dynamic vehicle system. A full vehicle model interacting with EPS control algorithm was concurrently simulated on a single bump road condition. The dynamic responses of vehicle chassis and steering system resulting from road surface impact were evaluated and compared with proving ground experimental data. The comparisons show reasonable agreement on tie-rod load, rack displacement, steering wheel torque and tire center acceleration. This concurrent simulation capability was employed fur EPS performance evaluation and calibration as well as for vehicle handling performance integration and synthesis.

• Journal of Mechanical Science and Technology
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• v.16 no.3
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• pp.338-343
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• 2002

In the autonomous vehicle, the reference lane is continually detected by machine vision system. And then the vehicle is steered to follow the reference yaw rates which are generated by the deviations of lateral distance and the yaw angle between a vehicle and the reference lane. To cope with the steering delay and the side-slip of vehicle, PI controller is introduced by yaw rate feedback and tuned from the simulation where the vehicle is modeled as 2 DOF and 79 DOF and verified by the results of an actual vehicle test. The lateral control algorithm by yaw rate feedback has good performances of lane tracking and passenger comfort.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.127-136
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• 2008

Vehicle stability is a very important subject in vehicle design and control, because vehicle safety is closely dependent upon its dynamic stability. The control logic for four-wheel steering(4WS) systems, in which maintaining at least the specified stability region is the control objective, was constructed using the simplified vehicle model of 3 degree-of-freedoms. The improvement of vehicle stability was verified through computer simulations for the slalom and the double lane change maneuver using the multi-body dynamic model in MSC.ADAMS.

• Journal of Information Technology Services
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• v.22 no.3
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• pp.85-100
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• 2023

The development of Airside Vehicle Control System(AVCS) at Gimpo Airport aims to reduce ground safety accidents in movement area and improve airport operation efficiency and safety management service quality. The vehicle is controlled by a brake controller RTK-antenna and On-Board Diagonostics(OBD) module. Location data is transmitted to a nearby communication base station through a Wi-Fi router and the base station is connected to the AVCS by an optical cable to transmit location data from each vehicle. The vehicle position is precisely corrected to display information using the system. The system allows airport operators to view registered information on aircraft and vehicles and monitor their locations speeds and directions in real time. When a vehicle approaches a dangerous area alarm warnings and remote brake control are possible to prevent accidents caused by carelessness of the driver in advance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.41-46
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• 2004

In this paper, we study the stabilization control if an underwater vehicle from its initial posture to its desired one. We assume tint the underwater vehicle has velocity constraint, i.e. it has no velocity component for some direction. Our approach is based on the nonholonomic system which am derived from velocity constraints that cannot integrable. We proposed a control strategy for posture control of the underwater vehicle using multi-rate digital control. The proposed control scheme is applied to the berthing control if an underwater vehicle and verified the effectiveness if control strategy by numerical simulation.

• International Journal of Automotive Technology
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• v.8 no.3
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• pp.299-308
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• 2007

This study proposes a two-layer hierarchical control system that integrates active front wheel steering and four wheel braking torque control to improve vehicle handling performance and stability. The first layer is a robust model matching controller (R-MMC) based on linear matrix inequalities (LMIs), which optimizes an active front steering angle compensation and a desired yaw moment control, and calculates reference wheel slip for the target wheel according to the desired yaw moment. The second layer is a moving sliding mode controller (MSMC) that can track the reference wheel slip in a predetermined time by commanding proper braking torque on the target wheel to achieve the desired yaw moment. Since vehicle sideslip angle measurement is difficult to achieve in practice, a sliding mode observer (SMO) that requires only vehicle yaw rate as the measured input is also developed in this study. The performance and robustness of the SMO and the integrated control system are demonstrated through comprehensive computer simulations. Simulation results reveal the satisfactory tracking ability of the SMO, and the superior improved vehicle handling performance, stability and robustness of the integrated control vehicle.