• Journal of the Institute of Convergence Signal Processing
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• v.22 no.4
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• pp.171-178
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• 2021

Caravans are easily affected by external physical factors and often cause dangerous situations for passengers. Therefore, in order to secure the stability of the passenger, there is a need to develop a sway reduction device capable of preventing the sway phenomenon in advance. This paper aims to minimize the hitch angle between the tow vehicle and the caravan. Specifically, the initial instability of the caravan is detected through an IMU sensor mounted on each of the tow vehicle and the caravan, and a control value is calculated to reduce errors from the Hitch angle and Hitch yaw rate using a PID controller. Different braking torques are generated, distributed, and controlled on the left and right brakes of the caravan according to the calculated control value. It could be verified through the driving experiment that the hitch angle was decreased compared to the case where the performance of the sway reduction device was not controlled, and the transverse stability improvement rate was improved by 94.49% compared to before control.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.150-159
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• 2010

The approach and landing phase of a re-entry vehicle is composed of Steep Glideslope phase, Circular Flare phase, Flare Maneuver phase. The trajectory planning algorithm with geometric parameters is studied in this paper for on-board trajectory planning. This algorithm generate reference trajectory rapidly considering safe landing of re-entry vehicle. In this paper, the Mamdani Fuzzy PD type controller for longitudinal and lateral control is designed which has robustness of nonlinear system. In addition, the simulation is performed including initial downrange and crossrange errors, and the results shows that the proposed fuzzy logic controller has good performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1992.10a
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• pp.8-13
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• 1992

최근 우리 나라도 자동차의 수요가 급격히 늘어나고 있고, 생산량도 급증하 고 있어 자동차 공업이 산업의 최고의 위치를 확보하게 되었다. 자동차는 최 신 종합 기계 구조물로서 전기, 전자, 제어에 이르기까지 거의 모든 분양의 학문적 이론과 기술을 도입하는 최첨단의 기계 장비인것이다. 따라서 그 부 가가치 또한 매우 큰 것이다. 자동차의 성능을 결정짓는 가장 커다란 요소는 주행 성능과 안정성 및 조종성이다. 주행성능이라 함은 자동차의 종방향 운 동에 관한 성능으로서 기관의 동력에 지배적인 영향을 받는 성능(동력 성능) 과 그 밖의 성능(타향 성능, 제동 성능)으로 구분된다. 또 안정성과 조종성이 라함은 자동차의 횡방향 운동에 관한 성능으로서 로울링과 요우잉을 포함시 킨 곡선 운동에 관한 성능을 일컫는다. 이러한 운동 성능을 좌우하는 것은 구조적인 설계의 양부와 스프링이나 댐퍼의 성능일 것이다. 자동차의 수많은 부품 중의 다수가 국산화 되어 있지 아니하고, 또한 이러한 부품들의 성능을 시험할 수 있는 장비의 수입 의존도가 높은 것은 업계나 학계 등에서 앞으 로 많은 연구가 이루어져야 할 점이다. 자동차의 충격 흡수기(shock absorber)의 검사기도 또한 수입 시험기에 의존하고 있었던 것이 현실이었 다. 이에 본 연구진은 이 검사기의 국산화에 착수 한 것이다. 자동차에 있어 서 충격 흡수기는 지면에서 오는 충격을 급속히 흡수하는 역할을 하여 자동 차의 주행 성능과 안정성을 높혀 주며, 승차감을 높혀 주는 중요한 부품이 다. 따라서 충격 흡수기의 양부의 판정은 대단히 중요한 것이다. 본 연구에 서는 충격 흡수기의 충격 흡수력(감쇠력)을 측정하여 감쇠 특성을 정도 높게 파악할 수 있는 시험기를 만드는데 그 목적을 두고 있다. 연구는 시험기의 구동부를 제작하는 기계부와, 제어 및 계측의 하드웨어를 담당하는 전기.전 자부및 실제로 기계를 구동, 제어하고 측정 결과를 기록하고 출력하는 부분 을 담당하는 소프트웨어 개발부로 나누어서 진행하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.2
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• pp.107-117
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• 1998

As the traffic congestion and parking problems in urban areas are increased the tall and narrow commuter vehicles have interested as a means to increase the utilization of existing freewa- ys and parking facilities. However, in hard cornering those vehicles could reduce stability against overturning compared to conventional vehicles. This tendency can be mitigated by tilting the body toward the inside of the turn. In this paper those tilting vehicles are considered in which at speed at least, the tilt angle is controlled by steering the front wheels. In other word, if the driver turns the steering wheel the tilt controller automatically steers the road wheel to tilt the body inside of the turn. Also, the dynamic tilting vehicle model with tire slip angles is constructed by adding the roll degree of freedom. Finally, through computer simulation the behaviors of the tilting vehicles are investigated.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.15-20
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• 2012

This study is to propose and develop an integrated dynamics control system to improve and enhance the lateral stability and handling performance. To achieve this target, we integrate an AFS and a 4WS systems with a fuzzy logic controller. The IDCS determines active additional steering angle of front wheel and controls the steering angle of rear wheel. The results show that the IDCS improves the lateral stability and controllability on dry asphalt and snow paved road when double lane change and step steering inputs are applied. Yaw rate of the IDCS vehicle tracks reference yaw rate very well and body slip angle is reduced about by 50%. Response time of the IDCS vehicle is also decreased.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1716-1721
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• 2005

Conventionally, 2WS is used for vehicle sleeting, which can only steering front wheel. In case of trying to high speed slalom or emergency through this kind of vehicle equipped 2WS, it may occur much of side slip angle. On the other hand, 4WS makes decreasing of side slip angle, outstandingly, so it is possible to support vehicle movement stable. And conventional ABS and TCS can only possible control the longitudinal movement of braking equipment and drive which can only availab to control of longitudinal direction. There after new braking system ESP was developed, which controls both of longitudinal and lateral, with adding of the function of controlling Active Yaw Moment. On this paper, we show about not only designing of improed braking and steering system through establishing of the integrated control system design of 4WS and ESP but also designing of the system contribute to precautious for advanced vehicle stability problem.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.8-16
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• 2014

This paper analyzes the effects of sideslip angle(SA) on the buzz margin of supersonic intake. The buzz margin is assumed to be stabilized by a controller which generates command depending only on the longitudinal sensor measurements. The analysis is performed based on three dimensional CFD results with which the sensor measurements can be simulated. In such a control system based on the longitudinal measurements, unexpected lateral flow perturbation results in the increase in the total angle of attack(TAoA), that causes the degradation of the engine intake performance. As a consequence, it is shown that the control stability is reduced such that additional control margin needs to be secured.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.240-249
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• 2013

This paper discusses the maneuvering control algorithm based on all-wheel independent driving and steering control techniques for special purpose 6WD/WS vehicles. The maneuvering control algorithms considering superior dynamic characteristics of high power in-wheel motors and independent steering system are designed to perform driving, steering, vehicle stability, and fault tolerant control. The maneuvering controller applies sliding and optimal control theories considering optimal torque distribution and friction circle related to the vertical tire force. The fault tolerant control algorithm is applied to obtain the similar maneuverability to that of the non-faulty vehicle. The simulations using the Matlab/Simulink dynamics model and experiments using HIL simulator mounting the real controllers with the designed control algorithms prove the improved performances in terms of vehicle stability and maneuverability.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1591-1592
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• 2007

본 논문에서는 상태궤환을 이용한 철도차량의 능동조향을 위한 제어기법에 대해 다루었다. 능동조향은 곡선부 주행시 발생되는 승차감 저하 및 차륜/레일의 마모, 소음을 줄이고 고속주행을 위한 조향성능 및 주행안정성을 확보하기 위한 기술이다. 논문에서 사용된 제어 방법은 반대차(Half Bogie) 차량모델을 기초로 측정된 휠-레일의 횡변위(Lateral Displacement) 와 요각(Yaw Ang;e)정보를 토대로 휠에 요모멘트를 제어하였으며 시뮬레이션을 통해 제안한 방법에 대한 성능을 검증하였다.

• Composites Research
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• v.15 no.3
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• pp.18-29
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• 2002

The bending vibration and thermal flutter instability of spacecraft booms modeled as circular thin-walled beams of closed cross-section and subjected to thermal radiation loading is investigated in this paper. The thin-walled beam model incorporates a number of nonclassical effects of transverse shear, primary and secondary warping, rotary inertia and anisotropy of constituent materials. Thermally induced vibration response characteristics of a composite thin walled beam exhibiting the circumferantially uniform system(CUS) configuration are exploited in connection with the structural flapwise bending-lagwise bending coupling resulting from directional properties of fiber reinforced composite materials and from ply stacking sequence. The numerical simulations display deflection time-history as a function of the ply-angle of fibers of the composite materials, damping factor, incident angle of solar heat flux, as well as the boundary of the thermal flutter instability domain. The adaptive control are provided by a system of piezoelectric devices whose sensing and actuating functions are combined and that are bonded or embedded into the host structure.