• 제어로봇시스템학회논문지
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• 제20권12호
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• pp.1246-1251
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• 2014

This article presents an optimum yaw moment distribution scheme for a vehicle with electronic stability control (ESC) and active rear steering (ARS). After computing the control yaw moment in the yaw moment controller, it should be distributed into tire forces, generated by ESC and ARS. In this paper, yaw moment distribution is formulated as an optimization problem. New objective function is proposed to tune the relative magnitudes of the tire forces. Weighed pseudo-inverse control allocation (WPCA) is adopted to solve the problem. To check the effectiveness of the proposed scheme, simulation is performed on a vehicle simulation package, CarSim. From the simulation, the proposed optimum yaw moment distribution scheme is shown to effective for vehicle stability control.

• 대한기계학회논문집A
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• 제40권12호
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• pp.997-1003
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• 2016

본 논문은 자세 제어 장치와 능동 후륜 조향장치를 가지는 통합 섀시 제어에서 요 모멘트 분배를 위해 적응 알고리즘을 적용하는 방법을 제안한다. 통합 섀시 제어는 상위제어기와 하위제어기로 구성된다. 상위제어기에서 슬라이딩 모드 제어 이론을 이용하여 차량을 안정화시키는데 필요한 제어 요 모멘트를 계산한다. 하위제어기에서는 제어 요 모멘트를 만들어 내기 위해 자세 제어 장치의 제동 압력과 능동 후륜 조향장치의 조향각을 결정하는 데에 적응 알고리즘을 적용한다. 차량 시뮬레이션 패키지인 CarSim에서 시뮬레이션을 수행하여 제안된 방법의 타당성을 검증한다.

• 대한기계학회논문집A
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• 제38권3호
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• pp.315-321
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• 2014

본 논문은 전자제어식 조향 및 제동 장치를 장착한 차량에 대해 고장 안전 기능을 가지는 통합 섀시 제어 시스템을 제안한다. 통합 섀시 제어 시스템에서 상위 제어기는 슬라이딩 모드 제어 이론을 이용하여 제어 요모멘트를 만들어 낸다. 하위 제어기는 가중 의사-역행렬 기반 제어 분배 방법(WPCA)으로 제어 요모멘트를 전자제어식 조향 및 제동 장치의 타이어 힘으로 분배한다. WPCA 의 가변 가중치를 조절하여 구동기 혹은 센서의 고장에 대처할 수 있다. 이러한 상황에서 WPCA 방법으로 가변 가중치를 최적화하여 요모멘트 분배 성능을 향상시키기 위해 시뮬레이션을 이용한 최적화 방법을 제안한다. 제안된 방법의 타당성을 검증하기 위해 차량 시뮬레이션 패키지인 CarSim 에서 시뮬레이션을 수행한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권2호
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• pp.209-217
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• 2016

Unlike conventional airplane, a WIG craft experiences righting moment and adverse yaw moment in banked turning in ground effect. Numerical simulations are carried out to study the aerodynamics of banked wing in ground effect. Configurations of rectangular wing and delta wing are considered, and performance of endplates and ailerons during banking are also studied. The study shows that righting moment increase nonlinearly with heeling angle, and endplates enhance the righting. The asymmetric aerodynamic distribution along span of wing with heeling angle introduces adverse yaw moment. Heeling in ground effect with small ground clearance increases the vertical aerodynamic force and makes WIG craft climb. Deflections of ailerons introduce lift decrease and a light pitching motion. Delta wing shows advantage in banked turning for smaller righting moment and adverse yaw moment during banking.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1126-1131
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• 2007

This paper presents unified chassis control (UCC) to improve the vehicle lateral stability. The unified chassis control implies combined control of active front steering (AFS), electronic stability control (ESC) and continuous damping control (CDC). A direct yaw moment controller based on a 2-D bicycle model is designed by using sliding mode control law. A direct roll moment controller based on a 2-D roll model is designed. The computed direct yaw moment and the direct roll moment are generated by AFS, ESP and CDC control modules respectively. A control authority of the AFS and the ESC is determined by tire slip angle. Computer simulation is conducted to evaluate the proposed integrated chassis controller by using the Matlab, simulink and the validated vehicle simulator. From the simulation results, it is shown that the proposed unified chassis control can provide with improved performance over the modular chassis control.

• 한국정밀공학회지
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• 제19권11호
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• pp.65-74
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• 2002

This paper examines the usefulness of a Brake Steer System (BSS), which uses differential brake forces for steering intervention in the context of Intelligent Transportation Systems (ITS). In order to help the car to turn, a yaw moment can be achieved by altering the left/right and front/rear brake distribution. This resulting yaw moment on the vehicle affects lateral position thereby providing a limited steering function. The steering function achieved through BSS can then be used to control lateral position in an unintended road departure system. A 8-DOF nonlinear vehicle model including STI tire model will be validated using the equations of motion of the vehicle. Then a controller will be developed. This controller, which will be a PID controller tuned by Ziegler-Nichols, will be designed to explore BSS feasibility by modifying the brake distribution through the control of the yaw rate of the vehicle.

• International Journal of Precision Engineering and Manufacturing
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• 제5권3호
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• pp.26-34
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• 2004

This paper examines the usefulness of a Brake Steer System(BSS), which uses differential brake forces for steering intervention in the context of Intelligent Transportation Systems(ITS). In order to help the car to turn, a yaw moment control was achieved by altering the left/right and front/rear brake distribution. This resulting yaw moment on the vehicle affects lateral position thereby providing a limited steering function. The steering function achieved through BSS was used to control lateral position in an unintended road departure system. A 8-DOF nonlinear vehicle model including STI tire model was validated using the equations of motion of the vehicle. Then a controller was developed. This controller, which is a PID controller tuned by Ziegler-Nichols, is designed to explore BSS feasibility by modifying the brake distribution through the control of the yaw rate of the vehicle.

• 대한기계학회논문집A
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• 제38권11호
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• pp.1291-1297
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• 2014

본 논문에서는 자세 제어 장치와 능동 후륜 조향을 이용한 통합 섀시 제어를 제안한다. 제어에 필요한 요 모멘트를 만들어 내기 위해 직접 요 모멘트 제어 방법을 이용한다. 가중 역행렬 기반 제어할당 방법을 이용하여 제어 요 모멘트를 자세 제어 장치의 제동력과 능동 후륜 조향의 조향각으로 분배한다. 가중 역행렬 기반 제어 할당 방법에 가변 가중치를 도입하여 다양한 구동기 조합을 표현하고 차량의 속도를 높이기 위해 시뮬레이션을 이용하여 가변 가중치를 최적화한다. 차량 시뮬레이션 패키지인 CarSim 에서 시뮬레이션을 수행하여 제안된 방법이 차량의 조종안정성과 횡방향 안정성을 향상시킨다는 사실을 검증한다.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1898-1913
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• 2006

This paper deals with the design of a yaw rate controller based on gain-scheduled H$\infty$ optimal control, which is intended to maintain the lateral stability of a vehicle. Uncertain factors such as vehicle mass and cornering stiffness in the vehicle yaw rate dynamics naturally call for the robustness of the feedback controller and thus H$\infty$ optimization technique is applied to synthesize a controller with guaranteed robust stability and performance against the model uncertainty. In the implementation stage, the feed-forward yaw moment by driver's steer input is estimated by the disturbance observer in order to determine the accurate compensatory moment. Finally, HILS results indicate that the proposed yaw rate controller can satisfactorily improve the lateral stability of an automobile.

• 제어로봇시스템학회논문지
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• 제19권1호
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• pp.45-55
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• 2013

With the recent advancement of control method and battery technology, the electric vehicle have been researched to replace the conventional vehicle with electric vehicle with the view point of the environmental concerns and energy conservation. An electric vehicle which is equipped with the independent front steering system and in-wheel motors has advantage in terms of control. For example, the different torque which generated by left and right wheels directly can make yaw moment and the independent steering using outer wheel control is able to reduce the sideslip angle. Using of independent steering and driving system, the 4 wheel electric vehicle can improve a performance better than conventional vehicle. In this paper, we consider the method for improving the cornering performance of independent front steering system and in-wheel motor used electric vehicle with the compensated outer wheel angle and direct yaw moment control. Simulation results show that the method can improve the cornering performance of 4 wheel electric vehicle. We also apply the steering motor failure to steer the vehicle turned by the torque difference without steering. This paper describes an independent front steering and driving, consist of three parts; Vehicle Model, Control Algorithm for independent steering and driving and simulation. First, vehicle model is application of TruckSim software for independent front steering and 4 wheel driving. Second, control algorithm describes the reduced sideslip and direct yaw moment method in view of cornering performance. Last is simulation and verification.