共查询到20条相似文献,搜索用时 218 毫秒
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横摆速度反馈控制式4WS由把前轮的转角信号传至后的转向传递钢索,将前轮动力转向齿条的运动变换成钢索运动的皮带轮总成及控制后轮转向的传动装置构成。转向初期主要是转角比例项K1(V)θf起作用,通过反相转向提高转向响应性,车辆开始转弯后由横摆速度比例项支配,在控制横摆速度的同时使后轮转向,ABS与主动4WS组合在一起进行控制,不仅能确保与传统ABS同样的稳定性,而且还能缩短制动蹁,并使最小转变半径减少0.5米。 相似文献
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以四轮转向汽车为研究对象,建立车辆四轮转向动力学模型。基于后轮主动转向控制方法,分别搭建四轮转向汽车前后轮转角成比例的主动转向控制模型以及基于车速和横摆角速度反馈的主动转向控制模型。在高速转向工况下,采用MATLAB/Simulink建立四轮转向汽车主动转向控制仿真模型进行对比仿真。仿真结果表明,该控制方法能够较好地减小车辆质心侧偏角及横摆角速度,保证车辆良好的轨迹跟踪能力,有效地改善了车辆的操纵稳定性。 相似文献
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比例控制四轮转向车辆运动特性分析 总被引:12,自引:0,他引:12
系统地分析了二自由度四轮转向汽车模型的运动方程,得出了质心侧偏角、横摆角速度与前轮转角的传递函数。在此基础上,对四轮转向样车进行了前后轮转角成比例控制的四轮转向车辆(4WS)的运动学仿真,并针对仿真结果进行了系统的分析。结果阐明了四轮转向车辆与前轮转向车辆(2WS)相比的优势,并提出其发展方向。 相似文献
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Masao Nagai Yutaka Hirano Sachiko Yamanaka 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1997,27(5):357-370
An integrated control system of active rear wheel steering (4WS) and direct yaw moment control (DYC) is presented in this paper. Because of the tire nonlinearity that is mainly due to the saturation of cornering forces, vehicle handling performance is improved but limited to a certain extent only by steering control. Direct yaw moment control using braking and/or driving forces is effective not only in linear but also nonlinear ranges of tire friction circle. The proposed control system is a model matching controller which makes the vehicle follow the desired dynamic model by the state feedback of both yaw rate and side slip angle. Various computer simulations are carried out and show that vehicle handling performance is much improved by the integrated control system. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5-6):357-370
SUMMARY An integrated control system of active rear wheel steering (4WS) and direct yaw moment control (DYC) is presented in this paper. Because of the tire nonlinearity that is mainly due to the saturation of cornering forces, vehicle handling performance is improved but limited to a certain extent only by steering control. Direct yaw moment control using braking and/or driving forces is effective not only in linear but also nonlinear ranges of tire friction circle. The proposed control system is a model matching controller which makes the vehicle follow the desired dynamic model by the state feedback of both yaw rate and side slip angle. Various computer simulations are carried out and show that vehicle handling performance is much improved by the integrated control system. 相似文献
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Design of Optimal Four-Wheel Steering System 总被引:6,自引:0,他引:6
Young H. Cho Graduate Student J. Kim Assistant Professor 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1995,24(9):661-682
Optimal design of the four wheel steering (4WS) system of the ground vehicle is studied. 4WS vehicles with the optimal control scheme are considered first. General formulation of the optimal control law is developed based on the linear quadratic regulator theory. The vehicle speed function (VSF) based 4WS vehicle with a simple feedback controller is considered as a special case of the optimal system. Two new designs of the VSF 4WS system are proposed and their performances are compared with the optimal 4WS systems and the existing VSF 4WS system. The first system is designed for the maximum stability while the second system is designed to emulate the response of the optimal 4WS vehicle. Advantages of the new VSF designs are discussed. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):529-546
A comparison between two different approaches to vehicle stability control is carried out, employing a robust non-parametric technique in the controller design. In particular, an enhanced internal model control strategy, together with a feedforward action and a suitably generated reference map, is employed for the control of a vehicle equipped either with a rear wheel steering (RWS) system or with a rear active differential (RAD) device. The uncertainty arising from the wide range of operating conditions is described by an additive model set employed in the controller design. Extensive steady state and transient tests simulated with an accurate 14 degrees of freedom nonlinear model of the considered vehicle show that both systems are able to improve handling and safety in normal driving conditions. RAD devices can make the vehicle reach higher lateral acceleration values but they achieve only slight stability improvements against oversteer. On the other hand, 4WS systems can greatly improve both vehicle safety and manoeuvrability in all driving situations, making this device an interesting and powerful stability system. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(9):661-682
SUMMARY Optimal design of the four wheel steering (4WS) system of the ground vehicle is studied. 4WS vehicles with the optimal control scheme are considered first. General formulation of the optimal control law is developed based on the linear quadratic regulator theory. The vehicle speed function (VSF) based 4WS vehicle with a simple feedback controller is considered as a special case of the optimal system. Two new designs of the VSF 4WS system are proposed and their performances are compared with the optimal 4WS systems and the existing VSF 4WS system. The first system is designed for the maximum stability while the second system is designed to emulate the response of the optimal 4WS vehicle. Advantages of the new VSF designs are discussed. 相似文献
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Publio Pintado Miguel-Angel Castell 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1999,31(3):137-155
The dynamic behavior of commercial vehicles fitted with differentr types of suspension mechanisms and steering devices is investigated in this paper. Six vehicle models have been constructed: 2WS-SA is a standard two wheel steering bus with solid axles; 2WS-DW is a 2WSA vehicle with independent double wishbone suspension in front and rear axles; SSA-SA is a 2WS system with solid axles, the rear one being mounted on a self steered mechanism; SSA-DW is a vehicle with independent double wishbone suspension in the front axle, and a solid self steered rear axle; 4WS-SA has four wheel steering with solid axles; and 4WS-DW is a 4WS vehicle with independent double wishbone suspension in front and rear axles. The dynamic response of these models has been assessed in terms of lateral acceleration, yaw velocity, tire forces, tire force reserves, and slip angles. The expected advantages of a 4WS system (higher acceleration rates and lower slip angles) will be corroborated but, at the same time, it will be shown that they are obtained at the cost of lower force reserves. Self steered mechanisms produce smaller body slip angles, but it will be shown that they give rise to larger yaw velocity overshootings. The particular independent suspension analyzed does not show significant improvements with respect to the solid axle counterpart. 相似文献
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This paper describes a drive controller designed to improve the lateral vehicle stability and maneuverability of a 6-wheel
drive / 6-wheel steering (6WD/6WS) vehicle. The drive controller consists of upper and lower level controllers. The upper
level controller is based on sliding control theory and determines both front and middle steering angle, additional net yaw
moment, and longitudinal net force according to the reference velocity and steering angle of a manual drive, remotely controlled,
autonomous controller. The lower level controller takes the desired longitudinal net force, yaw moment, and tire force information
as inputs and determines the additional front steering angle and distributed longitudinal tire force on each wheel. This controller
is based on optimal distribution control and takes into consideration the friction circle related to the vertical tire force
and friction coefficient acting on the road and tire. Distributed longitudinal/lateral tire forces are determined as proportion
to the size of the friction circle according to changes in driving conditions. The response of the 6WD/6WS vehicle implemented
with this drive controller has been evaluated via computer simulations conducted using the Matlab/Simulink dynamic model.
Computer simulations of an open loop under turning conditions and a closed-loop driver model subjected to double lane change
have been conducted to demonstrate the improved performance of the proposed drive controller over that of a conventional DYC. 相似文献
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Optimal Control of Four Wheel Steering Vehicle 总被引:4,自引:0,他引:4
A. Higuchi Assistant manager Y. Saitoh Emeritus professor of Tokyo University of Agriculture Technology 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(5):397-410
This paper derives a method of controlling four wheel steering using optimal control theory. The purpose of control is to minimize the sideslip angle at the center of gravity. The control method feeds forward the steering wheel angle and feeds back the yaw velocity and the sideslip angle to the front and rear wheel angles. Theoretical studies show that the sideslip angle is reduced to zero even in the transient state, and that the understeer characteristic and frequency response can be changed regardless of the vehicle static margin. This Paper also examines various characteristics of the influence of the side force nonlinearities of tires and crosswinds. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):1205-1227
The present paper proposes an automatic path-tracking controller of a four-wheel steering (4WS) vehicle based on the sliding mode control theory. The controller has an advantage in that the front- and rear-wheel steering can be decoupled at the front and rear control points, which are defined as centres of percussion with respect to the rear and front wheels, respectively. Numerical simulations using a 27-degree-of-freedom vehicle model demonstrated the following characteristics: (1) the automatic 4WS controller has a more stable and more precise path-tracking capability than the 2WS controller, and (2) the automatic 4WS controller has robust stability against system uncertainties such as cornering power perturbation, path radius fluctuation, and cross-wind disturbance. 相似文献