• Journal of Ocean Engineering and Technology
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• v.25 no.6
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• pp.116-122
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• 2011

A realtime simulator using an explicit integration method is introduced to improve the solving performance for the dynamic analysis of a wheeled vehicle. Because a full vehicle system has many parts, the development of a numerical technique for multiple d.o.f. and ground contacts has been required to achieve a realtime dynamics analysis. This study proposes an efficient realtime solving technique that considers the wheeled vehicle dynamics behavior with full degrees of freedom and wheel contact with soft ground such as sand or undersea ground. A combat vehicle was developed to verify this method, and its dynamics results are compared with commercial programs using implicit integration methods. The combat vehicle consists of a chassis, double wishbone type front and rear suspension, and drive train. Some cases of vehicle dynamics analysis are carried out to verify the realtime ratio.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.318-319
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• 2008

In this paper, a steering feel simulator is designed and implemented using a steering wheel with a rotation angle sensor, torque sensor, and an ac motor for the generation of the required torque. The controller in the simulator consists of a 16-bit micro-controller, a D/A converter and A/D converters. The main objective of the controller is to perform torque control where the reference torque is calculated from the torque map for both the vehicle velocity and the wheel sensor cutout. It is shown via the experimentation using the proposed simulator that the simulator output performance can be easily understood for the variation of vehicle parameters or controller parameters.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.162-170
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• 2004

In these days, a vehicle simulator is developed by using a VR(Virtual Reality) system. A VR system must provide a vehicle simulator with a natural interaction, a sufficient immersion and realistic images. To achieve this, it is important to provide a fast and uniform rendering performance regardless of the complexity of virtual worlds or the level of simulation. In this paper, modeling methods which offer an improved rendering performance for complex VR applications as 3D road model have been implemented and verified. The key idea of the methods is to reduce a load of VR system by means of LOD(Level of Detail), alpha blending texture mapping, texture mip-mapping and bilboard. Hence, in 3D road model where a simulation is complex or a scene is very large, the methods can provide uniform and acceptable frame rates. The VR system which is constructed with the methods has been experimented under the various application environments. It is confirmed that the proposed methods are effective and adequate to the VR system which associates with a vehicle simulator.

• Journal of IKEEE
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• v.22 no.4
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• pp.970-977
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• 2018

The autonomous vehicle is based on an advanced driver assistance system (ADAS) consisting of a sensor that collects information about the surrounding environment and a control module that determines the measured data. As interest in autonomous navigation technology grows recently, an easy development framework for ADAS beginners and learners is needed. However, existing development and verification methods are based on high performance vehicle simulator, which has drawbacks such as complexity of verification method and high cost. Also, most of the schemes do not provide the sensing data required by the ADAS directly from the simulator, which limits verification reliability. In this paper, we present an interactive ADAS development and verification framework using a 3D vehicle simulator that overcomes the problems of existing methods. ADAS with image recognition based artificial intelligence was implemented as a virtual sensor in a 3D car simulator, and autonomous driving verification was performed in real scenarios.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.159-166
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• 2006

Chassis system has a large influence on ride quality, stability and NVH performance of a car. To improve the performance and reduce cost, the development of chassis modular assemblies is emphasized. To develop chassis corner modules, it is necessary to predict the performance of full vehicle motion such as ride, handling performance, NVH characteristics and durability of modules. In this paper, full vehicle test is performed to acquire the road load data of chassis corner module of passenger car. 3-axis simulator modeling are carried out to simulate reaction force analysis and fatigue analysis of new developed modules. Also, real simulator tests to validate performance of new developed modules are performed. We had developed the accelerated durability test procedure of KATECH PG and it is used to test chassis corner modules at laboratory and simulate durability performance. All these results have been provided to module and parts company and make an important role to develop chassis corner modules.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.937-943
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• 2013

An independently driven electric corner module cannot be applied to an actual vehicle without some difficulty, because of vehicle safety problems in the case of malfunctions and degraded ride and handling performance owing to the increase in the unsprung mass. In this study, a simulator is developed to evaluate the vehicle driving performance in order to solve ride and handling problems. Component modeling of a small-sized electric vehicle with an independently driven electric corner module is performed using MATLAB/Simulink. The vehicle is modeled by using CarSim, which can be used to analyze the vehicle maneuvers with 27 DOFs. The control algorithm for the improvement of vehicle driving safety and ride and handling performance is validated by using the developed simulator.

• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.93-97
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• 2013

This paper is on designing an indoor driving simulator to evaluate the performance of in-car speech recognizer when influenced by the elements, which lower the success rate of speech recognition. The proposed simulator simulates vehicle noise which was pre-recorded in diverse driving environments and driver's speech. Additionally, the proposed Lombard effect conversion module in this simulator enables the speech recorded in a studio environment to convert into various possible driving scenarios. The relevant experimental results have confirmed that the proposed simulator is a feasible approach for realizing an effective method as it achieved similar speech recognition results to the real driving environment.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.195-201
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• 2005

In conventional Vehicle Stability Control (VSC) System, a control threshold is designed by average driver characteristics. Despite the stabilizing effort, VSC causes redundancy to an expert driver. An advanced VSC which has flexibility on its control property is proposed in this study. By using lateral velocity estimator, a control threshold is determined on side slip angle and angular velocity phase plane. Vehicle planar motion model based sliding controller is modified with respect to various control thresholds. The performance of the proposed VSC algorithm has been investigated by human-in-the-loop simulation using a vehicle simulator. The simulation results show that the control threshold has to be determined with respect to the driver steering characteristics. A VSC with variable control thresholds would provide an improvement compared to a VSC with a constant threshold.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.337-342
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• 2011

A roller rig has been widely used in the study about dynamic stability and railway safety. However, the cost for constructing the roller rig and the difficulty in adjusting the design parameters for vehicle systems lead to the development of a small scale simulator which is cheaper than the large scale test systems and easy to control the parameters affecting dynamic characteristics of the railway vehicle. For the operation of the small scale test system called a small scale simulator, it is required to investigate the performance and characteristics of the system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying of the test results and understanding of the physical behavior of the dynamic system comprising the small scale bogie and the simulator.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.127-130
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• 2017

In this research, we present a path planning method for an autonomous flight of unmanned aerial vehicles (UAVs) through reinforcement learning under simulated environment. We design the simulator for reinforcement learning of uav. Also we implement interface for compatibility of Deep Q-Network(DQN) and simulator. In this paper, we perform reinforcement learning through the simulator and DQN, and use Q-learning algorithm, which is a kind of reinforcement learning algorithms. Through experimentation, we verify performance of DQN-simulator. Finally, we evaluated the learning results and suggest path planning strategy using reinforcement learning.