• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.95-107
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• 2016

The axle weight of a vehicle in motion can be measured with a low-speed or high-speed weigh-in-motion (WIM). However, the axial load dynamically change depending on the vehicle's characteristics-such as the chassis or axle structure-or the characteristics of the driving environment such as road flatness. The changes in dynamic load lead to differences between the vehicle's weight measured at rest and the vehicle's weight measured in motion. For this Study, an experiment was conducted with an instrumented vehicle to analyze the range of errors caused by uncontrollable environmental factors by identifying the characteristics of the dynamic load changes of a vehicle in motion, and determine the appropriate scale for the accuracy evaluation of a high-speed WIM, as a preparatory research for the introduction of unmanned overweight enforcement systems in the future. The key findings from the experiment are summarized as follows. First, The gross weight of the tested vehicle changed by approximately 1% at low velocities and approximately by 4% at high velocities, and the vehicle's axle weight changed by approximately 1-3%, at low velocities and by 2-9% at high velocities. A single axle showed larger weight changes than individual axles in a group. Secondly, The vehicle's gross weight and the axle weight on the impact section were up to eight times and three-to-twelve times higher, respectively, than its gross weight and the axle weight on the flat section. The vibration frequency of the vehicle's dynamic load was measured at between 2.4 and 5.8Hz, and found to return to the normal amplitude after moving approximately 30 meters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.969-975
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• 2002

Visual effects are important cues for providing occupants with virtual reality in a vehicle simulator which imitates real driving. The viewpoint of an occupant is sensitively dependent upon the occupant's posture, therefore, the total human body motion must be considered in a graphic simulator. A real-time simulation is required for the dynamic analysis of complex human body motion. This study attempts to apply a neural network to the motion analysis in various driving situations. A full car of medium-sized vehicles was selected and modeled, and then analyzed using ADAMS in such driving conditions as bump-pass and lane-change for acquiring the accelerations of chassis of the vehicle model. A hybrid III 50%ile adult male dummy model was selected and modeled in an ellipsoid model. Multibody system analysis software, MADYMO, was used in the motion analysis of an occupant model in the seated position under the acceleration field of the vehicle model. Acceleration data of the head were collected as inputs to the viewpoint movement. Based on these data, a back-propagation neural network was composed to perform the real-time analysis of occupant motions under specified driving conditions and validated output of the composed neural network with MADYMO result in arbitrary driving scenario.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.185-188
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• 1999

An estimation algorithm for vehicle driving load has been proposed in this paper. Driving load is an important factor in a vehicle's longitudinal motion control. An approach using an observer is introduced to estimate driving load based on inexpensive RPM sensors currently being used in production vehicles. Also, a torque estimation technique using nonlinear characteristic functions has been incorporated in this estimation algorithm. Using a nonlinear full vehicle simulation model, we study the effect of the driving load on longitudinal vehicle motion, and the performance of the estimation algorithm has been evaluated. The proposed estimation algorithm has good performance and robustness over uncertainties in the system parameters. An accurate estimate of the driving load can be very helpful in the development of advance vehicle control systems such as intelligent cruise control systems, CW/CA systems and smooth shift control systems.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.166-175
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• 1999

This paper describes a design and performance evaluation of robust controller which overrides unstable motion and pulls out quickly after water entry of underwater vehicle dropped from aircraft or surface ship. We use 6-DOF equation for model of motions and assume parameter uncertainty to reflect the difference of real motion from modelled motion equation. we represent a nonlinear system with uncertainty as Takagi and Sugeno's(T-S) fuzzy models and design controller stabilizing them. The fuzzy controller utilizes the concept of so-called parallel distributed compensation (PDC). Finally, we confirm stability and performance of the controller through computer simulation and hardware in the loop simulation (HILS).

• International Journal of Automotive Technology
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• v.8 no.1
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• pp.49-57
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• 2007

This paper proposes a traction control system (TCS) that uses a sliding mode wheel slip controller and a PID throttle valve controller. In addition, a yaw motion controller (YMC) is also developed to improve lateral stability using a PID rear wheel steering angle controller. The dynamics of a vehicle and characteristics of the controllers are validated using a proposed full-car model. A driver model is also designed to steer the vehicle during maneuvers on a split ${\mu}$ road and double lane change maneuver. The simulation results show that the proposed full-car model is sufficient to predict vehicle responses accurately. The developed TCS provides improved acceleration performances on uniform slippery roads and split ${\mu}$ roads. When the vehicle is cornering and accelerating with the brake or engine TCS, understeer occurs. An integrated TCS eliminates these problems. The YMC with the integrated TCS improved the lateral stability and controllability of the vehicle.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.395-403
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• 2016

A cylinder-type underwater vehicle for military use that is running near the free surface at the final homing stage to hit a surface ship target is affected by wave force and moment. Since wave can affect an underwater vehicle running at the depth less than half of the modal wave length, it is important to confirm that the underwater vehicle can work well in such a situation. In this paper, wave force and moment per unit wave amplitude depending on wave frequency, wave direction, and vehicle's running depth were calculated by 3-Dimensional panel method, and the numerical results were modeled in external force terms of six degrees of freedom equations of motion. Motion simulation of the underwater vehicle running in various speed, depth, and sea state were performed.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.5
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• pp.249-256
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• 2000

This paper deals with the control of the lateral motion of a mobile vehicle. A mobile vehicle using in this experiment is able to adapt many unmanned automatic driving system, for example, like a automated product transporting system. This vehicle is consist of the two servomotors. One is used to accelerate this vehicle and the another is used to change this lateral direction. An adaptive fuzzy logic controller(AFLC) is designed and applied to a experimental mobile vehicle in order to achieve the control of the lateral direction. An adaptive fuzzy logic controller(AFLC) is designed and applied to a experimental mobile vehicle in order to achieve the control of the lateral motion of the vehicle. Therefore, the main aim of this paper is investigate the possibility of applying adaptive fuzzy control algorithms to a microprocessor-based servomotor controller which requires faster and more accurate response compared with many other industrial processes. Fuzzy control rules are derived by modelling an expert's driving actions. Experiments are performed using a mobile vehicle with sensing units, a microprocessor and a host computer.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.2
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• pp.77-87
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• 2024

In the present study, seakeeping performance for an amphibious vehicle in regular head waves was analyzed and evaluated experimentally and numerically. First, seakeeping tests were performed to confirm the vehicle's motion response of heave, pitch motion and vertical acceleration in restricted wavelength ratio conditions for a simplified vehicle shape. Numerical analyses were also conducted for a simplified vehicle shape to validate the numerical solver. To simulate the vehicle's motions, multi-degrees of freedom were calculated by a dynamic fluid-body interaction solver in STAR-CCM+. Comparison between numerical and experimental results was carried out for a simplified vehicle shape. Numerical results are in good agreement with experimental results. Second, numerical analyses were performed for a detailed vehicle shape considering seaway wavelength conditions. The seakeeping performance for an amphibious vehicle was evaluated by comparing with the existing ship's seakeeping performance standards.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.83-85
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• 2015

The Purpose of this paper was to carry out basic study on development of real-time submarine-hnadling simulator. The author adopt the Unmanned Undersea vehicle(UUV), which has taken the shape of manta[1]. They call here it Unmanned Undersea Vehicle(UUV). UUV is based on the same design concept as UUV called Manta Test Vehicle, which was originally built by the Naval Undersea Warfare Center, USA[1]. The present study deals with prediction of manoeuvring motion of UUV at general drift angles and large drift angles. The dynamic mathematical model with six degrees of freedom is revised and supplemented in order to describe accurately motion of UUV. The hydrodynamic derivatives related to motion are obtained from previous work[2].

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.328-341
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• 2010

The authors adopt the Unmanned Undersea Vehicle(UUV), which has taken the shape of manta(Sohn et al. 2006). They call here it Manta-type Unmanned Undersea Test Vehicle(MUUTV). MUUTV is designed with the similar concept of UUV called Manta Test Vehicle(MTV), which was originally built by the Naval Undersea Warfare Center, USA(Lisiewicz and French 2000, Sirmalis et al. 2001, U.S. Navy 2004). The present study deals with evaluation of extreme motion of MUUTV at large attack angles. Extreme motion contains, for example, rising and depth change due to operation of hovering thrusters attached to MUUTV, lateral motion due to ocean current applied to MUUTV at low advance velocity, and so on. Numerical simulation technique has been utilized. The previous mathematical model on manoeuvring motion of MUUTV(Bae et al. 2009a) is basically adopted. Based on the results of present model experiment on extreme motion, the mathematical model is revised and supplemented in order to describe extreme motion. The hydrodynamic derivatives related to extreme motion are obtained from present model experiment and the other derivatives are referred to previous work(Bae et al. 2009a).