• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.58-65
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• 2016

This study analyzed the structural weld strength for a door hinge for a field artillery ammunition support vehicle. In order to determine the optimal conditions, we measured the modal analysis and analyzed the leg length of a rear door hinge. From these methods, we acquired the vibration frequency of normal mode and the optimal welding leg length conditions. It was possible to obtain a structural stability for a rear door hinge of the field artillery ammunition support vehicle. In the future, this should be used as a reference source for the weld strength analysis of high vibration and high weight structures for another welding system design.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.399-413
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• 2006

Mathematical model for coupled motions of Manta-type Unmanned Undersea Vehicle(UUV) moving with six degrees of freedom, is formulated. Furthermore, a calculation method for estimating the linear hydrodynamic derivatives acting on UUV, is proposed, and some of the estimated linear hydrodynamic derivatives are compared with results of captive model experiment. Based on linear dynamic model of UUV, a study was made to examine dynamic stability and turning ability in horizontal plane. And directional stability and required elevation rudder angles for neutrally operating in vertical plane, are also discussed.

• Journal of ILASS-Korea
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• v.20 no.3
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• pp.156-161
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• 2015

This paper described the effect of dual clutch transmissions on the stability emissions characteristic in a GDI engine at vehicle Inspection and Maintenance(I/M) program. In order to investigate the influence of direct injection gasoline engine with DCT, the experimental apparatus consisted of GDI engine with 4 cylinder, dynamometer and exhaust emissions analyzer. Analyzed emission gas include CO, HC and NOx results that DCT vehicle in the case of NOx, HC in automatic transmission vehicles less than 1/2 level was confirmed to be exhausted. However vehicle specific power increases CO also has increased.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.83-90
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• 2007

The vehicle dynamic control system needs to detect the yaw rate of vehicle and a yaw rate sensor is required as a central component. Therefore, A sensor on the basic of the "tuning fork method" for automotive controls is being developed. The sensor was fabricated by the surface micro machining process to miniaturize its size. The sensor output offset is ${\pm}0.37^{\circ}/sec$ in the room temperature. The resonance frequency of the fabricated yaw rate sensor is measured to 5.29kHz for the drive mode. Tests of the sensor demonstrate that its performance is equivalent to that required for implementation of a yaw control system. Vehicle handling and safety are substantially improved using the sensor to implement yaw control.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.487-492
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• 2000

Yaw moment control algorithm for improving stability of a vehicle in cornering is presented in this paper. A change of the yaw moment according to an increment in brake ship at each wheel is examined and reflected in the control algorithm. This control algorithm computes the target yaw velocity as the vehicle motion desired by the driver for directional stability control in cornering and it makes the actual yaw velocity follow the target one. The yaw moment control was achieved by brake slip control and simple brake slip control logic was introduced in this paper.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.168-175
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• 1996

Except the collision avoidance performance related to the rapid lane change, the 4WS vehicle has better dynamic stability and handling performance than the conventional 2WS vehicle which has close relation with the driver's safety, a 4WS conrol method with the effect of steering wheel angular velocity is proposed based on the fact that the driver steers abruptly the steering wheel to avoid the collision. And the effects of the proposed 4WS control method are investigated on the dynamic stability and handling performance by using the ISO lane change test code.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.295-302
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• 2001

The lateral stability of curved continuous welded rail (CWR) is studied fur buckling prevention. This study includes the influences of vehicle induced loads on the thermal buckling behavior of straight and curved CWR tracks. quasi-static loads model is assumed to determine the uplift region, which occurs due to the vertical track deformation induced by wheel loads of vehicle. Parametric numerical analyses are performed to calculate the upper and lower critical buckling temperatures of CWR tracks. The parameters include track lateral resistance, track curvature, longitudinal stiffness, tie-ballast friction coefficient, axle load, truck center spacing, and the ratio of lateral to vertical vehicle load. This study provides a guideline for the improvement or stability for dynamic buckling in on tracks.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.53-59
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• 2022

This paper describes an integrated control of torque vectoring and rear wheel steering using model predictive control. The control objective is to minimize the yaw rate and body side slip angle errors with chattering alleviation. The proposed model predictive controller is devised using a linear parameter-varying (LPV) vehicle model with real time estimation of the varying model parameters. The proposed controller has been investigated via computer simulations. In the simulation results, the performance of the proposed controller has been compared with uncontrolled cases. The simulation results show that the proposed algorithm can improve the lateral stability and handling performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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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.

• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.54-59
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• 2009

In this paper, the effect of the position and size of a lumped mass on the structural stability of a high speed underwater vehicle is presented. For simplicity, a real vehicle was modeled as a follower force subjected beam that was resting on an elastic foundation, and the lumped mass effect was simplified as an elastic intermediate support. The stability of the simplified model was numerically analyzed based on the Finite element method (FEM). This numerical simulation revealed that flutter type instability or divergence type instability occurs, depending on the position and stiffness of the elastic intermediate support, which implies that the instability of the real model is affected by the position and size of the lumped mass.