• 제어로봇시스템학회논문지
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• 제17권4호
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• pp.313-320
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• 2011

Multi-axle driving vehicles that are used in special environments require high driving performance, steering performance, and stability. Among these vehicles, 6WS/6WD vehicles with middle wheels have structural safety by distributing the load and reducing the pitch angle during rapid acceleration and braking. 6WS/6WD vehicles are favored for military use in off road operations because of their high maneuverability and mobility on extreme terrains and obstacles. 6WD vehicles that using in-wheel motor can generate the independent wheel torque without other mechanical parts. Conventional vehicles, however, cannot generate an opposite driving force at each side wheel. Using an independent steering and driving system, six-wheel vehicles can show better performance than conventional vehicles. Using of independent steering and driving system, the 6 wheel vehicle can improve a performance better than conventional vehicle. This vehicle enhances the maneuverability under low speed and the stability at high speed. This paper describes an independent 6WS/6WD vehicle, consists of three parts; Vehicle Model, Control Algorithm for 6WS/6WD and Simulation. First, vehicle model is application of TruckSim software for 6WS and 6WD. Second, control algorithm describes the optimum tire force distribution method in view of energy saving. Last is simulation and verification.

• 한국융합학회논문지
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• 제3권4호
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• pp.35-44
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• 2012

본 연구에서 모사 프로그램이 6WD/6WS를 가진 특수 목적 차량의 비정상상태 코너링 성능을 조사하기 위해 개발되었다. 6WD 차량은 비포장 도로에서 작전을 수행하기 좋은 성능을 가지고 있고 안전한 성능을 가진 것으로 신뢰받고 있다. 그러나, 6WS 차량들의 코너링 성능은 관련 문헌을 통해서는 언뜻 이해가 어렵다. 본 논문에서는 6WD/6WS 차량들은 비선형 차량 동력학, 타이어 모델, 운동학적 효과 등을 포함한 18 자유도 시스템으로 모델링 되었다. 그리고 그 차량 모델은 입/출력과 차량변수가 수식화된 접근 방법으로 쉽게 변환될 수 있도록 MATLAB/SIMULINK를 사용한 모사 프로그램으로 구성되었다. 6WS 차량의 코너링 성능은 브레이크 휠과 피봇팅 각각으로 해석되었다. 모사 결과들을 보면, 코너링 성능은 전후 휠 조향 뿐만이 아니라 중간 휠 조향에 따라 좌우됨을 보여준다. 덧붙여, 새로운 6WS 제어법칙은 측면 미끄러짐 각을 최소화하기 위해 제안되었다. 차량변경 모사 결과들은 제안된 제어법칙의 6WS 차량의 장점을 보여준다.

• 한국자동차공학회논문집
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• 제5권6호
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• pp.155-166
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• 1997

In this study, a simulation tool is developed in order to investigate non steady-state cornering performance of 6WD/6WS special-purpose vehicles. 6WD vehicles are believed to have good performance on off-the-road maneuvering and to have fail-safe capabilities. But the cornering performances of 6WS vehicles are not well understood in the related literature. In this paper, 6WD/6WS vehicles are modeled as a 18 DOF system which includes non-linear vehicle dynamics, tire models, and kinematic effects. Then the vehicle model is constructed into a simulation tool using the MATLAB /SIMULINK so that input/output and vehicle parameters can be changed easily with the modulated approach. Cornering performance of the 6WS vehicle is analyzed for brake steering and pivoting, respectively. Simulation results show that cornering performance depends on the middle-wheel steering as well as front/rear wheel steering. In addition, a new 6WS control law is proposed in order to minimize the sideslip angle. Lane change simulation results demonstrate the advantage of 6WS vehicles with the proposed control law.

• 한국군사과학기술학회지
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• 제13권6호
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• pp.958-966
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• 2010

In this paper, we have proposed a integrated dynamic control architecture in 6WD(wheel drive)/6WS(wheel steering) vehicle for military applications. Since 6WD/6WS vehicle has inherent redundancy, the input variables to make any desired vehicle motion can not be determined uniquely. Therefore, optimal distribution method of tire forces is introduced, which is based on workload of each tire. Simulation result shows that this is effective for the energy minimization and dynamic performance enhancement. We also suggest how the integrated control with any failure mode should be reconstructed.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.632-638
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• 2010

This paper presents an optimum tire force distribution method for 6WD/6WS(6-Wheel-Drive and 6-Wheel-Steering) electric vehicles. Using an independent steering and driving system, the performance of 6WD/6WS vehicles can be improved, as, for example, with respect to their maneuverability under low speed and their stability at high speed. Therefore, there should be a control strategy for finding the optimum tire forces that satisfy the driver's command and minimize energy consumption. From the driver's commands (steering angle and accelerator/brake pedal stroke), the desired yaw moment, the desired lateral force, and the desired longitudinal force were obtained. These three values were distributed to each wheel as the torque and the steering angle, based on the optimum tire force distribution method. The optimum tire force distribution method finds the longitudinal/lateral tire forces of each wheel that minimize the cost function, which is the sum of the normalized tire forces. Next, the longitudinal/lateral tire forces of each wheel are converted into the reference torque inputs and the steering wheel angle inputs. The proposed method was tested through a simulation, and its effectiveness was verified.

• 제어로봇시스템학회논문지
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• 제16권4호
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• pp.353-360
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• 2010

A skid-steering method which applied to the various mobile robot platforms currently shows its effectiveness in the specified field areas and purposes. This system contains however, several problems of its intrinsic properties such as slippages occurred by different moving direction between vehicle's driving and wheel's rotary and difficulties of driving performance control and so on. This paper deals with the suggestion of suitable control algorithm for 6WD/6WS skid steering wheeled vehicle and verified its feasibility by analyzing the behavior of 6WD/6WS skid-steered wheeled vehicle model and by applying the engineering analytical method to the considered mobile platform. The Performance of vehicle model is evaluated by using slip mode control to follow the steering input and, as a future work, this control algorithm could be applied to real 6WD/6WS in-wheel drive type vehicle finally.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1523-1531
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• 2011

본 다축 차량은 험지와 야전에서 높은 이동성 때문에 비포장도로를 주행해야 하는 군용차량으로 사용된다. 특히 군용차량은 군 요구 사항에 의거 기본적으로 60% 경사로에서 안정적인 등판 성능을 지녀야 한다. 따라서 본 논문은 최적 타이어 힘 분배 방법을 통한 6WD/6WS차량의 등판능력 향상을 다루었다. 경사로 등판 시 사용할 최적 타이어 힘 분배 방법을 위하여 운전자로부터, 목표로 하는 종 방향 힘과 횡 방향 힘, 요 모멘트를 계산하였고, 마찰 원이론과 목적함수에 따른 최적화 된 토크가 각 륜에 분배되었다. 알고리즘 성능을 확인하기 위해서, 트럭심 소프트웨어를 이용하여 시뮬레이션 하였고, 비교를 위하여 2대의 차량을 제안하였다. 한 대의 차량은 최적타이어 힘 분배 방법이 적용되었고, 나머지 한 대는 궤도 차량과 같은 균등 힘 분배 방법이 적용되었다. 경사로에서 등판능력은 최적 타이어 힘 분배 방법에 의해서 향상 되어졌다.

• 한국군사과학기술학회지
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• 제16권3호
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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.

• 한국생산제조학회지
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• 제7권6호
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• pp.141-148
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• 1998

A loader is construction & road or agricultural machinery for lifting, moving, and mixing. This study deals with the agricultural mini loader for stock raising farming. The performance of the machine is established by pulling power, working lifting capacity, and minimum circling radius, etc. Also, driving easiness and endurance are very important in manufacturing. Thus, this study has developed the loader with the 4-wheel driving equipment by gear transmission, the 4-wheel steering equipment by power handle steering type, and the equipment making four wheels touch simultaneously on the rugged ground. The developed loader having these functions was very fit in a small cattle shed or a rugged ground. This study is divided into two parts; (I) development of 4WS transmission and (II) construction of the loader by 4WS system and other equipments.

• 미생물학회지
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• 제43권4호
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• pp.311-316
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• 2007

탄소원으로 thiodiglycol(TDG)을 함유한 배지에서 농후배양하여 인삼토양으로부터 TDG 분해균을 분리하였다. 분리균 WS-32의 형태적, 생화학적, 유전학적 특성을 조사한 결과 분리균이 Alcaligenes faecalis와 유사한 생화학적 성질을 지니고 있으며, 16S rRNA 서열이 Cupriavidus 속 균주와 유사도가 높은 균주로 판명되었다. WS-32는 $33^{\circ}C{\sim}37^{\circ}C$, pH $6.0{\sim}8.0$에서 성장이 우수하였으며, TDG에 의해 성장에 약간의 저해를 받지만, 배양후기에서는 이를 탄소원으로 이용하는 현상을 보였다. HPLC를 통해 배양액 내 잔존하는 TDG를 분석한 결과 2일 배양하였을 때 배지내 잔존하는 TDG가 상당량 감소한 것으로 확인되었다. 분리균 WD-32의 균체 파쇄상등액은 TDG의 산화활성을 보였으며, pH 8.0과 $45^{\circ}C$에서 산화활성이 가장 높았다.