• ETRI Journal
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• 제38권3호
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• pp.579-588
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• 2016

To improve the ability to determine a vehicle's movement information even in a challenging environment, a hybrid approach called non-Gaussian square rootunscented particle filtering (nGSR-UPF) is presented. This approach combines a square root-unscented Kalman filter (SR-UKF) and a particle filter (PF) to determinate the vehicle state where measurement noises are taken as a finite Gaussian kernel mixture and are approximated using a sparse Gaussian kernel density estimation method. During an outage-free GPS period, the updated mean and covariance, computed using SR-UKF, are estimated based on a GPS observation update. During a complete GPS outage, nGSR-UPF operates in prediction mode. Indeed, because the inertial sensors used suffer from a large drift in this case, SR-UKF-based importance density is then responsible for shifting the weighted particles toward the high-likelihood regions to improve the accuracy of the vehicle state. The proposed method is compared with some existing estimation methods and the experiment results prove that nGSR-UPF is the most accurate during both outage-free and complete-outage GPS periods.

• 한국소음진동공학회논문집
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• 제23권5호
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• pp.463-471
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• 2013

This paper presents design and control of electronic control suspension(ECS) equipped with controllable magnetorheological(MR) damper for passenger vehicle. In order to achieve this goal, a cylindrical type MR fluid damper that satisfies design specification of a middle-sized commercial passenger vehicle is proposed. After manufacturing the MR damper with design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of a conventional damper. A quarter-vehicle MR ECS system consisting of sprung mass, spring, tire, controller and the MR damper is established in order to investigate the ride comfort performances. On the basis of the governing equation of motion of the suspension system, five control strategies(soft, hard, comfort, sport and optimal mode) are formulated. The proposed control strategies are then experimentally realized with the quarter-vehicle MR ECS system. Control performances such as vertical acceleration of the car body and tire deflection are evaluated in frequency domains on random road condition. In addition, performance comparison of WRMS(weighted root mean square) of the quarter-vehicle MR ECS system on random road are undertaken in order to investigate ride comfort characteristics.

• 전자공학회논문지
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• 제54권2호
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• pp.3-8
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• 2017

본 논문은 차량 내부에서 무선 에너지 전송 기술을 지원하기 위해 분산 안테나 시스템의 사용을 제안한다. 차량 내 무선 에너지 전송 시스템은 에너지 수신 단말기의 이동이 제한적이고, 채널 환경이 정적이며, 인체가 송신기와 가까운 특징을 갖는다. 이러한 상황에서 송신기의 배치는 인체에서의 수신 에너지와 에너지 수신 단말기에서의 수신 에너지의 양에 큰 영향을 미친다. 이에 본 논문은 기존 무선 통신 시스템에서 사용되는 중앙 집중형 안테나 시스템과 분산 안테나 시스템을 적용하였을 때의 차량 내 무선 에너지 전송 성능을 모의실험을 통해 비교하고, 분산 안테나 시스템이 더 좋은 성능을 가짐을 보인다.

• 한국전기전자재료학회논문지
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• 제29권11호
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• pp.696-701
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• 2016

In this study, to increase output of road piezoelectric energy harvester, it was made into rack type in which many piezoelectric materials can be installed and load transfer device of the leverage type to transfer vehicle load was made. By paving it in the road, the output characteristics depending on vehicle load and speed were evaluated. Changing vehicle load, harvester output characteristics depending on speed changes were evaluated at the interval of 10 km/h from 10 km/h to 100 km/h. Also, by making a wireless switch and sending wireless signal with output of rack type harvester, whether to receive it was evaluated by distance. It was checked that all switches work up to front-to-back 100 m from harvester.

• 한국인터넷방송통신학회논문지
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• 제12권5호
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• pp.31-37
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• 2012

본 논문에서는 무선 센서 네트워크를 활용하여 스마트그리드와 전기자동차의 충전 시스템 연계과정을 효과적으로 파악하고, 안티아일랜딩 기능을 적용하여 전기자동차 충전계통과 연계된 스마트그리드 모니터링 시스템을 제안한다. 스마트그리드 모니터링 시스템은 지그비(ZigBee)통신을 통해 무선으로 전력 모니터링 데이터를 수신하며, 별도의 물리적 연결 없이 원격 제어를 통해 전기자동차의 충전제어가 가능하다. 또한, 그리드 내 독립전원에 아일랜딩 현상이 발생하면, 아일랜딩 현상이 발생한 독립전원을 즉시 감지하여 차단하고 다른 독립전원으로 대체하여 그리드의 안정적인 운용을 하도록 하며, 실험을 통하여 스마트그리드 모니터링 시스템의 성능을 확인한다.

• Journal of Power Electronics
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• 제19권2호
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• pp.403-412
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• 2019

Aiming at the problems of large dv/dt and di/dt in traditional single-ended converters and high electromagnetic interference (EMI) noise levels, a single-ended isolated converter using the secondary resonance technique is proposed in this paper. In the proposed converter, the voltage stress of the main power switch can be reduced and the voltage across the output diode is clamped to the output voltage when compared to the conventional flyback converter. In addition, the peak current stress through the main power switch can be decreased and zero current switching (ZCS) of the output diode can be achieved through the resonance technique. Moreover, the EMI noise coupling path and an equivalent model of the proposed converter topology are presented through the operational principle of the proposed converter. Analysis results indicate that the common mode (CM) EMI noise and the differential mode (DM) EMI noise of such a converter are deduced since the frequency spectra of the equivalent controlled voltage sources and controlled current source are decreased when compared with the traditional flyback converter. Furthermore, appropriate parameter selection of the resonant circuit network can increase the equivalent impedance in the EMI coupling path in the low frequency range, which further reduces the common mode interference. Finally, a simulation model and a 60W experimental prototype of the proposed converter are built and tested. Experimental results verify the theoretical analysis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.511-514
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• 2005

This paper propose an advanced control strategy to improve vehicle handling and directional stability by integrating Active Front Steering(AFS) with Electronic Stability Program(ESP) . The effect of the integrated control system on the vehicle handling characteristics and directional stability is studied through a close loop computer simulation of and eight degree of freedom nonlinear vehicle model and driver model. Simulation results confirm the effectiveness of the proposed control system and the overall improvements in vehicle handling and directional stability

• 한국철도학회논문집
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• 제9권4호
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• pp.473-481
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• 2006

This study attempts to estimate economic benefits in terms of cost sayings and qualitative effects resulting ken implementation of new vehicle maintenance information system. It is widely expected that the effect of new vehicle maintenance information system will be significant in cost savings by information sharing and electronic documentation. To evaluate the economic feasibility of new system implementation, the study conducted seven subsystems case studies on the vehicle maintenance information system of Seoul Metro. Economic benefits are estimated by measuring the time savings, in turn, are calculated into cost savings by multiplying the average wages per hour of employee. The result of case study showed that over the 20 billion Won will be saved owing to new vehicle information system implementation. In conclusion, this study will contribute to the field of practices for the most, in evaluation of the economic benefits resulting from new information system implementation in the railway organization.

• 전자공학회논문지B
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• 제30B권6호
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• pp.100-108
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• 1993

In this paper, noticing the point of human's ability which appropriately cope with vague conditions, we design fuzzy traffic signal light controller similar to human's distinction ability and decide the optimum cycle most suited to any traffic junction using fuzzy identification algorithm. In this study, for the control output decision process we design fuzzy controller better than electronic vehicle actuated controller in performance. We propose the cycle decision method which is not limited by the variance of traffic junction vehicle number through overcoming the limit of Webster's method which is adopted by the fixed cycle controller. Simulated experimental results show that fuzzy controller and fuzzy identification algorithm are better than the existing electronic vehicle actuated controller and fixed cycle controller in delay time per vehicle.

• 정보저장시스템학회논문집
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• 제11권2호
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• pp.26-30
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• 2015

Recently, military vehicles are driven with a lot of electronic devices such as radar, antenna, and information storage devices. However, the military vehicles can be exposed to impact easily. Therefore, they have to be designed robustly in order to ensure the stability of the vehicle and the electronic devices. To achieve that, the dynamic behaviors of the military vehicle should be exactly identified. Therefore, in this research, dynamic behaviors of the vehicles were identified by carrying out road tests and we constructed finite element model to analyze the dynamic characteristics of the vehicle.