• Annual Conference of KIPS
• /
• 2015.10a
• /
• pp.962-965
• /
• 2015

차량 전장용 소프트웨어는 자동차 전자 장비들을 제어하는 만큼 그 정확성과 안전성이 검증되어야 한다. 본 연구에서는 차량 전장용 제어 소프트웨어의 제어논리가 프로그래머가 의도한 데로 구성되어 있는지를 코딩단계에서 실험하고 가시화하는 도구를 개발하였다. 이를 위해 제어 소프트웨어와 함께 컴파일될 전장용 운영체제의 정형 모델을 구축하고 운영체제 구현과는 독립적으로 제어 프로그램에서 정의된 Task들의 수행 순서를 모의 실험하여 차량 전장용 운영체제의 Task 상태 변화를 확인할 수 있도록 하였다. 임의 생성된 제어프로그램 코드와 실제 차량 전장용 제어프로그램 코드에 개발된 도구를 적용하여 그 효용성을 확인하였다.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.5
• /
• pp.575-582
• /
• 2019

Advanced driving assist system can support safety of driver and passengers which may require vehicle dynamics states as well as road geometry. It is essential to have in real-time estimation of related variables and parameters. Among the road geometry parameters, road slope angle which can not be measured is essential parameter in pose estimation, adaptive cruise control and others on sag road. In this paper, Kalman filter based method for the estimation of the vehicle dynamics and road slope angle using a nonlinear vehicle model is proposed. It uses a combination of Kalman filter as Cascade Extended Kalman Filter. CEKF uses measured vehicle states such as yaw rate, longitudinal/lateral acceleration and velocity. Unknown vehicle parameters such as center of gravity and inertia are obtained by 2 D.O.F lateral model and experimentally. Simulation and Experimental tests conducted with commercialized vehicle dynamics model and real-car.

• Journal of Magnetics
• /
• v.18 no.3
• /
• pp.268-275
• /
• 2013

This paper shows the characteristics of performance for interior permanent magnet machine (IPM) considering driving conditions such as maximum torque per ampere (MTPA) and flux-weakening control especially in terms of harmonic loss. In particular, based on finite element analysis (FEA), permanent magnet (PM) eddycurrent loss and the harmonic iron loss have been computed where the models have been intentionally designed to identify the effects of pole-slot combinations on the loss while maintaining the required power for electric vehicle. From the analysis results, it was shown that the rotor iron loss and PM eddy-current loss of machine employing fractional slot winding are extremely large at load condition. Furthermore, it was revealed that the harmonic iron loss at high-speed operation is mainly distributed over stator teeth and rotor surface, which may aggravate cooling system of the rotor structure in the vehicle.

• Journal of Drive and Control
• /
• v.15 no.4
• /
• pp.67-73
• /
• 2018

The paper deals with an approach to time domain simulation for closed end at the downstream of pipe, hydraulic lines terminating into a tank and series lines with change of cross sectional area. Time domain simulation of a fluid power systems containing hydraulic lines is very complex and difficult if the transfer functions consist of hyperbolic Bessel functions which is the case for the distributed parameter dissipative model. In this paper, the magnitudes and phases of the complex transfer functions of hydraulic lines are calculated, and the MATLAB Toolbox is used to formulate a rational polynomial approximation for these transfer functions in the frequency domain. The approximated transfer functions are accurate over a designated frequency range, and used to analyze the time domain response. This approach is usefully to simulate fluid power systems with hydraulic lines without to approximate the frequency dependent viscous friction.

• Advances in materials Research
• /
• v.7 no.2
• /
• pp.105-118
• /
• 2018

Magnesium and its alloys are attracted towards all engineering applications like automotive, marine, aerospace etc. due to its inherent high strength to weight ratio. But, extensive use of Mg alloys is limited to the current scenario because of low wear and corrosion resistance behavior. However, equal channel angular press is one of the severe plastic deformation technique which has been effective method to improve the wear and corrosion resistance by achieving fine grain structure. In this study, the effect of grain refinement on wear and corrosion resistance of AZ80 Mg alloys were investigated. The wear behavior of the coarse and fine-grained Mg alloys was examined through $L_9$ orthogonal array experiments in order to comprehend the wear behavior under varies control parameters. It was shown that ECAPed alloy increased the wear and corrosion resistance of the Mg alloy through the formation of fine grain and uniform distribution of secondary ${\beta}-phase$. Also, the performance of AZ80 Mg alloy for these changeswas discussed through SEM morphology.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.9
• /
• pp.105-109
• /
• 2022

In this study, the cause of the acceleration failure of Hyundai Motor's 2.0-liter CRDi engine was analyzed. We tried to find problems through MDA (Measuring Data Analyzer) based on data such as vehicle speed, air intake, and air-fuel ratio obtained during the actual driving process. As a result, it was analyzed that the failure of the EGR valve exceeded the NOx emission standard and caused a decrease in engine output. Through this study, it is possible to reduce the time and cost of unnecessary maintenance and repair, and it is expected that a rapid cause analysis will be possible in the case of new failure diagnosis in the future.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.5
• /
• pp.881-888
• /
• 2022

Servo presses are used in variety of ways in industry throughout the production and assembly lines of machine parts. The bottom of the servo press is fixed to a bed or a tabletop, and the press cylinder continuously operates under vertical upward loads. In this research, a static structural analysis was performed by simplifying 3D model of the servo press, and the maximum deformation was applied to the clamp and bolt. The maximum value of Von Mises stress was reported in this paper. The result was used to calculate the safety factor, and it was confirmed that the design was conservative.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.2_2
• /
• pp.265-272
• /
• 2023

In this paper, we directly implemented the Line Tracer ROS package that can detect and follow lines drawn on the map on Gazebo, an open-source that is widely used in autonomous driving research. For line detection, the cv_bridge package was used to enable OpenCV's image processing tools, and parameters such as robot speed, line color and ground material could be changed. In addition, proportional (P) and PID controls could be implemented using the color centroid obtained through image processing. Through this approach, the effect of proportional and differential coefficients on the robot's line tracer motion could be analyzed effectively. In addition, by displaying robot simulation results using various tools of ROS, an efficient development for control nodes could be established in ROS.

• Annual Conference of KIPS
• /
• 2023.05a
• /
• pp.134-136
• /
• 2023

안드로이드는 오픈소스로 많은 제조 업체들이 자신들의 서비스에 맞게 커스터마이징 하기도 한다. 다만, 접근 제어 정책들을 올바르지 못하게 수정하거나 추가함에 있어서 발생하는 취약점을 통해 공격자가 해당 접근 제어 메커니즘을 우회하여 보안적 위험 문제가 발생할 수 있다. 이에 따라 안드로이드의 다양한 접근 제어 정책들을 살펴보고, 제조 업체가 추가하는 접근 제어 정책을 검사하거나 발생하는 취약점에 따라 우회할 수 있는 방법들을 찾아내는 최근 연구들의 동향을 분석하고자 하며 앞으로의 관련 연구의 지속적인 필요성을 제시한다.

• Journal of Hydrogen and New Energy
• /
• v.35 no.2
• /
• pp.230-239
• /
• 2024

Efforts are being made to replace ship diesel engines with electric propulsion motors in response to emission regulations. In particular, in the case of short-range small ships, research is being conducted to replace polymer electrolyte membrane fuel cells (PEMFC) with power sources. However, PEMFC has problems such as slow dynamic response characteristics and reduced durability at high temperatures. To solve this problem, a high-precision ship model was developed with power distribution and thermal management strategies applied, and through this, the required power, heat, and power characteristics of the propulsion system according to the ship's speed profile were analyzed.