• 한국지능시스템학회논문지
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• 제25권2호
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• pp.168-173
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• 2015

비행 시 외부 조건에 따라 비선형시변 동적특성을 갖는 항공기의 비행제어는 종 제어(longitudinal control)와 횡 제어(lateral control)로 나눌 수 있으며, 종 제어는 승강키(elevator)에 의한 피치(pitch)값, 횡 제어는 에일러론(aileron)에 의한 롤(roll)값과 방향키(rudder)에 의한 요(yaw)값들을 제어대상으로 삼는다. 현재까지 항공기의 안정성, 조종성 그리고 기동성을 보장하기 위한 제어시스템 개발에 많은 연구들이 활발히 진행되어 왔으나, 최근에는 다양하고 복잡한 풍동실험과 환경실험들을 필요로 하는 기존연구들과는 다른 항공기의 지능제어시스템 개발에 관련된 연구들이 이루어지고 있다. 본 논문은 대표적인 지능제어방식인 Interval Type-2 퍼지논리기법에 의한 항공기 종 제어시스템을 제시하고 F-4 제트전투기의 컴퓨터 모의실험을 통해 그 효용성을 입증한다.

• 제어로봇시스템학회논문지
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• 제13권9호
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• pp.875-882
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• 2007

In order for a vehicle to follow a predetermined trajectory accurately, its position must be estimated accurately and reliably. In this thesis, we propose trajectory tracking control methods for unmanned vehicle and a positioning system using ultrasonic wave. The positioning problem is an important part of control problem for unmanned navigation of a vehicle. Dead Reckoning is widely used for positioning of vehicle. However this method has problems because it accumulates estimation errors. We propose a new method to increase the accuracy of position estimation using the Ultrasonic Satellite System (USAT). It is shown that we will be able to estimate the position of vehicle precisely, in which errors are not accumulated. And proposed trajectory tracking control methods include both a new path planning method and a lateral control method for vehicle. The experimental results show that the proposed methods enables exact vehicle trajectory tracking even under various environmental factors.

• 한국자동차공학회논문집
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• 제8권5호
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• pp.165-172
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• 2000

The VDC(Vehicle Dynamic Control) is a control system whose target is to improve stability of a vehicle under lateral motion. A lateral vehicle motion, especially on a slippery road, can lead to a hazardous situation, and the situation can even worsen by the driver`s inappropriate response. In this paper, two VDC systems, a fuzzy-based controller and an LQR-based controller have been developed. The controllers take as input the yaw rate and the sideslip angle of either body or rear wheel, and they yield the direct yaw moment signal by which the vehicle can gain stability during cornering. Simulations have been conducted to evaluate the performance of the control system. The results indicated that the controllers can successfully improve vehicle stability under potentially dangerous driving conditions.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권6호
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• pp.295-301
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• 2001

In this paper, an impedance control using a serial chain of spring-damper system is proposed for a vehicle platoon. For safety of the vehicle platoon, it is required to regulated the distance between each vehicle at a preassigned value even in case of vehicle model error, or moise in the measurement signal. Since the spring-damper system is physically stable and widely used to represent the interaction with the uncertain environments, it is appropriate to the longitudinal control of the vehicle platoon. By considering the nonholonomic characteristics of the vehicle motion, the lateral control and the longitudinal control of the vehicle paltoon are unified in the proposed algorithm. Computer simulation is carried out to verify the robustness against the uncertainties such as the vehicle model error and the measurement noise.

• 자동차안전학회지
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• 제14권4호
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• pp.53-59
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• 2022

This paper describes an integrated control of torque vectoring and rear wheel steering using model predictive control. The control objective is to minimize the yaw rate and body side slip angle errors with chattering alleviation. The proposed model predictive controller is devised using a linear parameter-varying (LPV) vehicle model with real time estimation of the varying model parameters. The proposed controller has been investigated via computer simulations. In the simulation results, the performance of the proposed controller has been compared with uncontrolled cases. The simulation results show that the proposed algorithm can improve the lateral stability and handling performance.

• Archives of Reconstructive Microsurgery
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• 제17권1호
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• pp.28-35
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• 2008

The purpose of this study was to present the clinical analysis of the results of lateral arm free flap for small sized and infected diabetic foot ulcer around toes. From May 2006 to December 2007, Seven patients were included in our study. Average age was 52.8 years, six were males and one was female. All had infected diabetic foot ulcer and had exposures of bone or tendon structures. Ulcers were located around great toe in four patients, 4th toe in one and 5th toe in two. Three patients had osteomyelitis of metatarsal or phalanx. After appropriate control of infection by serial wound debridement and intravenous antibiotics, lateral arm flap was applied to cover remained soft tissue defects. Posterior radial collateral artery of lateral arm flap was reanastomosed to dorsalis pedis artery of recipient foot by end to side technique in all cases in order to preserve already compromised artery of diabetic foot. All flaps were designed over lateral epicondyle to get longer pedicle and averaged pedicle length was 8 cm. Two cases were used as a sensate flap to achieve protective sensation of foot. All flaps survived and provided satisfactory coverage of soft tissue defects on diabetc foot ulcers. All patients could achieve full weight-bearing ambulation. No patients has had recurrence of infection, ulceration and further toe amputations. There were three complications, a delayed wound healing of flap with surrounding tissue, a partial peripheral loss of flap and a numbness of forearm below donor site. All patients were satisfied with their clinical results, especially preserving their toes and could return to the previous activity levels. Lateral arm free flap could be recommend for infected diabetic foot ulcers around toes, to preserve toes, coverage of soft tissue defect and control of infection with low donor site morbidity.

• 대한기계학회논문집A
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• 제28권12호
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• pp.1937-1941
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• 2004

We present lateral actuated piezoelectric actuator using U-shaped PZT strip and lever structure for the RF switch application. In the previous study of RF switch, they used horizontal contact switch fabricated by thin film metals. However, thin film metals could not generate large contact force due to low stiffness. In this work, we suggest lateral contact switch which makes large contact force by increasing stiffness. In addition, we use PZT actuator for the high force actuation. Generally actuator using thin film PZT moves to the vertical direction due to the neutral axis shift. Therefore we need lateral motion generation mechanism based on the thin film PZT actuator. In order to increase lateral motion of thin film PZT actuator, we use U-shaped PZT actuator using residual stress control. Also, thin film PZT actuator can generate very small lateral motion of 120${\times}$10$^{-6}$ ${\mu}{\textrm}{m}$/V for d$_{31}$ mode, thus we suggest lever structure to increase stroke amplification. From the experimental study, fabricated PZT actuator shows maximum lateral displacement of 1 ${\mu}{\textrm}{m}$, and break down voltage of the thin film PZT actuator is above 16V.

• 대한치과교정학회지
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• 제16권1호
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• pp.119-131
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• 1986

The purpose of the study is to note the effects of the resection of the lateral pterygoid muscle on the mandibular growth in the growing rats. Twenty four female Wistar rats were used in the experiment. They were divided into three groups: group 1 ; bilateral sham operation group 2 ; bilateral resenction of the lateral pterygoid muscle group 3 ; unilateral resection of the lateral pterygoid muscle (The right lateral pterygoid muscle was resected and the left one was sham-operated.) Groups 1&2 were sacrificed eight weeks lateral and group 3, four weeks later. All specimens were measured with calipers, and stained with hematoxylin and eosin. Groups 1 & 2 were compared with each other. In group 3, the right side was compared with the left. The results were as follows: 1. In the growing rats, the resection of the lateral pterygoid muscle was followed by a decrease of the mandibular growth. After eight weeks, the condyle-mental foramen distance, the angular process-mental foramen distance, the size of the condylar head, the supradentale-first molar distance, and the diameter of the symphysis were significantly smaller than the control. 2. Resection of the lateral pterygoid muscle resulted in decrease of the thickness of the cartilage layer and the prechondroblastic-chondroblastic layer after four weeks. 3. After eight weeks, group 1 and group 2 were not different significantly in the histologic sections. 4. The condylar cartilage was stabilized eight weeks after the experiment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.619-623
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• 1993

In this paper, a neural network is appled to design a lateral autopilot for airplanes. Linearized lateral dynamics is used in training the neural network controller and verifying the performance as well. To train the neural network, back propagation algorithm is used. In this training, no information about the dynamics to be controlled except sign and rough magnitude of control derivatives is needed. It is shown by computer simulations that the performance and stability margin are satisfactory.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1014-1019
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• 2005

In this paper, a neural network technique for automatic steering control of a four wheel drive autonomous highway snowplow vehicle is presented. Controllers are designed by the LQR method based on the vehicle model. Then, neural network is used as an auxiliary controller to minimize lateral tracking error under the presence of load. Simulation studies of LQR control and neural network control are conducted for the vehicle model under a virtual snowplowing situation. Tracking performances are also compared for two and four wheeled steering vehicles.