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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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为对某四轮驱动车辆在驱动工况下操纵稳定性进行研究,利用Madab软件建立了七自由度车辆动力学仿真模型,并对其在驱动工况下前轮转角阶跃输入和其相应稳态工况进行了对比分析,对其在驱动工况下前轮转角正弦输入响应情况作了描述,仿真结果表明在驱动工况下转弯能够明显增大汽车不足转向趋势,同时验证了模型的有效性,可为相关研究提供理论依据。 相似文献
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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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为了解车辆转向的内在特性,给车辆转向控制方法提供理论研究基础,依据非线性系统动力学结构稳定性理论,提出了车辆转向动力学分岔理论。基于车辆转向动力学分岔理论对车辆转向动力学特性进行了研究;以车辆前轮转角、车辆纵向速度及后轮转角为分岔参数,研究其对车辆质心侧偏角、横摆角速度的影响规律,得出了车辆在不同转向状态下的稳定转向区间。研究结果表明:车辆稳态转向时不发生动态Hopf分岔,而发生静态鞍结分岔;理论研究结果与车辆实际运行情况相符,非线性系统结构稳定性理论用于车辆转向动力学研究是正确、合理的。 相似文献
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车辆操纵性的准确预测对评价车辆的动力学性能至关重要,通过动力学分析软件Adams/Chassis预测了车辆的操纵性并进行了实车验证.建立的车辆模型考虑了弹性元件,转向摩擦力和阻尼的影响.对4种代表操纵特性的行驶工况进行了仿真试验:稳态回转,正弦转向,斜坡脉冲转向和阶跃转向.实车验证时的相关度分析中不仅包含了方向盘转角,转向力矩,整车侧向加速度、侧偏角、侧倾角,同时包含了侧倾角梯度.和最终的实测数据对比后,仿真数据和实测数据的相关性很好,结果表明Adams/Chassis仿真软件可以对车辆操纵特性进行准确的预测,同时此种方法可以用在车辆早期的概念设计阶段动力学性能开发和随后的调试阶段. 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
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Effect of the Controller Parameters on the Steerability of the Four Wheel Steered Car 总被引:1,自引:0,他引:1
L szl PALKOVICS 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1992,21(1):109-128
The four-wheel-steering systems of the cars are becoming more and more wide-spread. In addition to the conventional 4WS systems (e.g. the steering-wheel-angle dependent four-wheel-steering and the speed dependent 4WS) there already exist some so called active 4WS systems. The front wheels and rear wheels are steered autonomously by the feedback compensation and in this manner the behaviour of the car during high-speed turning manoeuvre and under the side wind gust is improved. But what happens if some of the parameters of the car are changed? In the present paper, the author will analyze the system's response when the internal tyre pressure in the rear wheels is lower than the normal. Due to this the under-steered car becomes over-steered and the question is whether the control system is able to stabilize the motion of the vehicle. 相似文献
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三轴汽车前后轮角输入时的响应特性 总被引:5,自引:0,他引:5
本文详细推导了三轴汽车线性二自由度模型的运动微分方程,分析了汽车对前后轮角输入时的移居记响应特性。从汽车动力学的角度讨论了前后轮转应具备的比例关系。该方法同样适用于其它多轴汽车的建模分析。 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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I. ech 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1994,23(1):133-148
A vehicle model incorporating front and rear wheel suspensions and seat suspension is presented. The suspension control includes algorithms to provide both dynamic and steady state (levelling) control. Vehicle response to (a) vertical inputs due to ground disturbances at the wheels and (b) longitudinal inputs due to the inertial forces during braking and accelerating, are investigated. It is shown that the static (self-levelling) control causes a slight deterioration in dynamic performance. The active ride control produces improvements of ride comfort under dynamic conditions compared to an equivalent passively suspended vehicle. In steady state the proposed control eliminates the error heave of the body caused by tilting of the vehicle with active suspension. 相似文献
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四轮转向车辆多体仿真与试验研究 总被引:1,自引:0,他引:1
以四轮转向原理样车为对象,运用多体动力学理论对四轮转向车辆的转向特性进行了计算机仿真研究和试验验证。对建立整车多体模型的方法进行了论述。通过对仿真数据与样车试验结果的对比分析,证明了四轮转向多体模型各类参数和控制方法的正确性和适用性。最后利用建立的整车多体模型,仿真分析了前后悬架刚度对操纵稳定性的影响,以及制动转向时的转向响应特性。 相似文献
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K. Riedl P. Lugner 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1982,11(3):175-193
Detailed Investigations of the Steady State Turning of Single Track Vehicles
In the paper the steady state turning of single track vehicles on a horizontal, even road is investigated, supposing the air to be at rest. The vehicle model used has six degrees of freedom: rolling, yawing, pitching and bouncing of the vehicle, rotation of the front wheel system (steering) relatively to the main frame and distortion of the rear wheel system due to limited stiffness of its linkage, and also takes into account wind drag and gyroscopic effects generated by wheels and other vehicle components. A special importance is given to the geometry of the vehicle
The results show a comparison of two types of motorcycles with different geometries and tires. To characterize the vehicle behaviour the roll, side slip and steering angle as functions of the normal acceleration are used. A more detailed study in respect to the steering torque is added. 相似文献
In the paper the steady state turning of single track vehicles on a horizontal, even road is investigated, supposing the air to be at rest. The vehicle model used has six degrees of freedom: rolling, yawing, pitching and bouncing of the vehicle, rotation of the front wheel system (steering) relatively to the main frame and distortion of the rear wheel system due to limited stiffness of its linkage, and also takes into account wind drag and gyroscopic effects generated by wheels and other vehicle components. A special importance is given to the geometry of the vehicle
The results show a comparison of two types of motorcycles with different geometries and tires. To characterize the vehicle behaviour the roll, side slip and steering angle as functions of the normal acceleration are used. A more detailed study in respect to the steering torque is added. 相似文献
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S. Motoyama Engineer H. Uki Engineer K. ISODA Manager H. YUASA Manager 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(5):455-464
The purpose of this study is to clarify vehicle dynamics effected by traction force distribution, not only between the front and rear wheels but also between the left and right wheels. Contribution of traction force distribution to vehicle turning performance was investigated using a mathematical simulation and an experimental vehicle. The results indicates that the control of traction control distribution between the left and right wheels greatly influences vehicle turning characteristics and improve the performance even in a marginal turning condition. 相似文献