• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.607_608
• /
• 2009

일반적으로 매입형 영구자석 동기전동기는 영구자석의 사용량이 많을수록 돌극비를 향상 시킬 수 있으므로 발생토크 중 릴럭턴스 토크의 비중을 키울 수 있다. 이는 토크 발생 시 입력전류를 저감시켜 동손이 감소하고 효율을 향상시키는 효과를 기대할 수 있다. 하지만 최근에 희토류계 영규자석의 가격 상승으로 인하여 영구자석 형 전동기 개발에 있어 제약이 따르는 상황이며 가격 경쟁력을 위하여 영구자석의 사용량을 저감시키는 노력을 기울이고 있다. 본 논문에서는 HEV 구동용 매입형 영구자석 동기전동기를 대상으로 영구자석 사용량 저감 설계에 대하여 다루고자 한다. 영구자석 사용량 저감은 영구자석의 두께를 변경시켜서 검토하였으며 실험을 통한 영구자석의 감자특성을 검토하여 최적의 두께를 결정하였다. 영구자석 두께 저감에 따라 감소한 최대출력 확보를 위하여 회전자의 형상설계를 기계적 구조해석과 병행하여 수행하였다. 최종으로 설계된 모델의 특성은 Prototype과 비교하여 성능만족 여부 및 영구자석 사용량 변화를 확인하였다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.4
• /
• pp.103-109
• /
• 2008

Semi-spherical CVT(SS-CVT) is one of friction drives, which transmits power via the friction force between a spherical shaped variator and output disks. The variator varies the speed ratio of SS-CVT continuously as well as transmits input power into the output shaft. Therefore two friction forces are normally applied on the variator; one is the longitudinal friction force for power transmission and the other is the lateral for shifting. In order to investigate the dynamic behavior of SS-CVT, we introduced a numerical model of 2-dimensional friction force using a function of slip ratio and slip angle. And a dynamic model, which describes the shifting mechanism of SS-CVT, is developed through 3-dimensional vector analysis. Finally we presented numerical results of the shift characteristics focused on the transient behavior of the variator's slip ratio and slip angle. The numerical results also show the typical CVT shifting characteristics of SS-CVT and stable shifting behaviors of the variator.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.42 no.2
• /
• pp.49-61
• /
• 2017

The study on the efficiency analysis of Korean automobile parts companies is mostly based on the calculation of the size of output such as sales. However, the performance indicators such as sales, operating profit, and net profit are directly related to the cost structure, and this cost structure is affected by changes in the company's asset structure and capital structure. As a result, it is necessary that efficient capital procurement should be done at the same time to create efficient management performance through proper investment. In this study, we aim to measure the efficiency of asset and capital procurement compared to the sales figures, such as sales, generated by 33 primary suppliers who supply parts to Hyundai Kia Motors. For this purpose, this study proposed a DEA cross analysis model that can simultaneously measure efficiency in terms of input assets and capital procurement based on the same management performance when analyzing the efficiency of domestic auto parts companies.

• Laser Solutions
• /
• v.7 no.3
• /
• pp.11-24
• /
• 2004

In automotive industry, light weight vehicle is one of issues because of the air pollution and the protection of environment. Therefore, automotive manufacturers have tried to apply light materials such as aluminum to car body. Aluminum welding using laser has some advantages high energy density and high productivity. It is very important to understand behavior of plasma and keyhole in order to improve weld quality and monitor the weld state. In this study, spectral analysis was carried out to verify the spectrum for plasma which is generated in laser welding of A 6000 aluminum alloy. Two photodiodes which cover the range of plasma wavelength was used to measure light emission during laser welding according to assist gas flow rate and welding speed. Analysis of relationship between sensor signals of welding variables and formation of keyhole and plasma is performed. To determine the level of significance, analysis of variation (ANOVA) was carried out.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.3
• /
• pp.179-186
• /
• 2015

In this paper, a novel lateral control system is proposed for the purpose of improving lane keeping performance which is independent from GPS signals. Lane keeping is a key function for the realization of unmanned driving systems. In order to obtain this objective, a vision sensor based real-time lane detection scheme is developed. Furthermore, we employ a data fusion along with a real-time steering angle of the test vehicle to improve its lane keeping performance. The fused direction data can be obtained by an IMU sensor and vision sensor. The performance of the proposed system was verified by computer simulations along with field tests using MOHAVE, a commercial vehicle from Kia Motors of Korea.

• Proceedings of the KIEE Conference
• /
• 2005.11a
• /
• pp.33-35
• /
• 2005

In this paper, a two-mass system for SiOG (Silicon on Glass) vibratory gyroscope with the need of frequency tuning was proposed to increase the stability of the device with wide bandwidth. Air damping and bandwidth were analyzed using MATLAB. The measured resonance frequency is 5.2 kHz, which is 7 kHz in the design. But the measured bandwidth is 450 Hz, similar to the designed bandwidth with 500 Hz. Also the frequency difference (210 Hz) between the driving and sensing part is smaller than the wide bandwidth of two mass system.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.756-757
• /
• 2008

Interior permanent magnet synchronous motor (IPMSM) which has high power density is usually applied to traction motor for hybrid electric vehicle. In order to analyze characteristics of IPMSM, d- and q-axis equivalent circuit analysis is generally used. However, the line current of IPMSM calculated by d- and q-axis equivalent circuit analysis differ from measured value. This error is mainly appeared under the flux weakening control. In order to reduce the error between calculated and measured line current, no-load linkage flux which is calculated with considering saturation of magnetic core and armature reaction is applied to characteristic analysis. The result of line current calculated by the method dealt with in this paper is verified by comparison with experimental results.

• IE interfaces
• /
• v.21 no.3
• /
• pp.294-301
• /
• 2008

Agile and flexible manufacturing systems make it mandatory that a control program should have features such as agility, flexibility, and reusability in order to run manufacturing unit smoothly. PLCs are the most frequently used control program in manufacturing systems. PLC programs are mostly programmed by subcontraction, which makes correction of code very difficult. As a result, it may cause delay during down time and ramp up time which leads to big loss of revenue and goodwill. To prevent delay during the times, this paper proposes systematic process analysis and application method for programmable logic controller like LLD (Ladder Logic Diagram). The proposed method uses modified human-error investing techniques for documentation and transforming technique to program LLD from the documentation. Furthermore, this paper demonstrates an example of piston mechanism to explain the proposed method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.1
• /
• pp.79-87
• /
• 1996

SMC(Sheet Molding Compound) is made of unsaturated polyester resin and other additives reinforced with randomly distributed chopped fiberglass strands. Because of its higher stiffness per unit mass, SMC was used as a substitute for steel for automotive steel outer panels. Thus, understanding of flow characteristics during fabrication of SMC is of importance since the formation of weld line depends on material flow. In the present study, SMC compression molding simulations in the flat and T-shape molds were accomplished. During simulations, the preferential the preferential flow occurred at the low mold closing speed while plug flow was observed for the higher mold closing speed. When the preferential flow was observed, the weld line was seen at the final stage. For simulations, rigid-viscoplastic finite element method was applied. Self-contact algorithm was also applied in order to predict the formation of the weld line. Simulation results were compared to the experimental results available in the literature.

• Journal of Korean Society for Quality Management
• /
• v.41 no.2
• /
• pp.185-196
• /
• 2013

Purpose: This paper is focused on introducing the Automotive Functional Safety International Standard-ISO 26262 and proposing effective countermeasures of ISO 26262. Methods: We studied collected data about ISO 26262 and analyzed the relationship between ISO 26262 and Quality 5 Star of Hyundai Kia Motors for the integrated product development process. Results: Results showed the product development process for the integration plan between ISO 26262 and Quality 5 Star. In addition, we added an entry about the functional safety in the evaluation item of Quality 5 Star System. Conclusion: In order to introduce ISO 26262 effectively, we proposed ISO 26262 requirements and functional safety concept to be added to Quality 5 Star.