共查询到19条相似文献,搜索用时 218 毫秒
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《世界汽车》2014,(11)
Q1:我对别克全新SUV昂科威非常感兴趣,听说它的四驱系统比较特别,请编辑老师介绍一下。
上海读者:杜天宇
A1:昂科威搭载的是适时四驱系统,提供两种不同版本供消费者选择,官方将两种四驱分别命名为“智能四驱”与“全路况智能四驱”,二者主要区别在于左右后轮动力分配。官方公布的资料显示,智能四驱主要会配备在精英版与豪华版车型上,其后桥配备一个多片离合器式限滑差速器,正常情况下以前驱为主,当系统监测到车轮打滑时,通过压紧离合器片将部分动力传递至后轮,以达到分配前后动力的目的。这套智能四驱系统的后桥限滑差速器装配在靠近左后轮的位置,在车轮不打滑时,后轮是不会获得任何动力的。由于是以前驱为主的四驱车型,如果两个前轮均处于打滑状态,车辆脱困则更多依靠车轮上的电子限滑辅助系统对车轮进行制动,从而达到脱困的效果。全路况智能四驱系统配备于旗舰版与运动旗舰版车型上,其与智能四驱系统主要区别在于它后桥上布置了两个多片离合器式限滑差速器,从前桥而来的动力可以通过两个限滑差速器按需分配给左右后轮,这样的方式无论在城市路面行驶还是在复杂路况下行驶时对车辆的行驶稳定性以及通过性都有很大的帮助。总体而言,昂科威的适时四驱系统结构并不算复杂,通过布置于后桥的多片离合器式限滑差速器达到分配后轮转矩的目的。 相似文献
上海读者:杜天宇
A1:昂科威搭载的是适时四驱系统,提供两种不同版本供消费者选择,官方将两种四驱分别命名为“智能四驱”与“全路况智能四驱”,二者主要区别在于左右后轮动力分配。官方公布的资料显示,智能四驱主要会配备在精英版与豪华版车型上,其后桥配备一个多片离合器式限滑差速器,正常情况下以前驱为主,当系统监测到车轮打滑时,通过压紧离合器片将部分动力传递至后轮,以达到分配前后动力的目的。这套智能四驱系统的后桥限滑差速器装配在靠近左后轮的位置,在车轮不打滑时,后轮是不会获得任何动力的。由于是以前驱为主的四驱车型,如果两个前轮均处于打滑状态,车辆脱困则更多依靠车轮上的电子限滑辅助系统对车轮进行制动,从而达到脱困的效果。全路况智能四驱系统配备于旗舰版与运动旗舰版车型上,其与智能四驱系统主要区别在于它后桥上布置了两个多片离合器式限滑差速器,从前桥而来的动力可以通过两个限滑差速器按需分配给左右后轮,这样的方式无论在城市路面行驶还是在复杂路况下行驶时对车辆的行驶稳定性以及通过性都有很大的帮助。总体而言,昂科威的适时四驱系统结构并不算复杂,通过布置于后桥的多片离合器式限滑差速器达到分配后轮转矩的目的。 相似文献
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<正>2023年路虎新揽胜配备了由捷豹路虎公司自行开发的四轮转向(AWS)系统。配备AWS的车辆安装了前后两个转向器,该系统可自动操纵车辆后轮的转向。在低至中等车速下的四轮转向如图1所示,后轮转向方向与前轮相反,以减少转弯直径并增加车辆的灵活性,从而便于完成泊车操控。在较高车速下如图2所示,后轮的转向方向与前轮相同以增强操控时的车辆稳定性。 相似文献
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美国克莱斯勒和福特等公司对1991年型轿车的改进方案主要有制动系、转向系和悬架等三个方面: 一、四轮转向道奇′91年型全新R/T双涡轮“司蒂尔斯”牌赛车为首先装备自制四轮动力转向系统的车辆,当汽车时速大于48km时,后轮与前轮的同一方向转弯,并能增加操纵灵敏度和高速稳定性,而在时速低于48km时又成为传统的两轮转向方式,使后轮保持在随动状态。这种仅适用于R/T双涡轮赛车的四轮动力转向系统有一根活动的连杆,并能将改变后轮转角的操纵杆连接于二个拉臂上,从而形成一个随动的凹轮转向装置;当前轮转弯时可使后轮的转角作小量的改变,见图1,但在后悬架差速器上还安装一个油泵以驱动一个“微型齿条”,以便在前轮转弯时对后轮作出反应,见图2。后轮的转角很小仅1.5°,但已足以使各种行驶条件下的操纵产生显著的改良效果。后轮转向角的变化与车速和转弯的大小以及驾驶员使用转向助力的强弱成正比。斯蒂尔断赛车的常四轮驱动独立悬架,有一个中央硅酮粘液耦合器,当需要时可将45%驱动力矩分配至前轮,而将55%分配至后轮;全车还配有电子式缓冲装置和防抱制动器。 相似文献
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论述了电控限滑差速器(ELSD)改善汽车动力学特性的原理,提出了基于提高汽车主动安全性的控制方法。该方法利用前馈与误差反馈控制相结合来控制车辆运动状态。反馈系数根据最优控制的方法确定。通过对所述控制系统的仿真研究,证明该系统在各种路面条件下均可明显改善汽车的操纵稳定性与主动安全性。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):1685-1704
ABSTRACTThe handling characteristic is a classical topic of vehicle dynamics. Usually, vehicle handling is studied by analyzing the understeer coefficient in quasi-steady-state maneuvers. In this paper, experimental tests are performed on an electric vehicle with four independent motors, which is able to reproduce front-wheel-drive, rear-wheel-drive and all-wheel-drive (FWD, RWD and AWD, respectively) architectures. The handling characteristics of each architecture are inferred through classical and new concepts. The study presents a procedure to compute the longitudinal and lateral tire forces, which is based on a first estimate and a subsequent correction of the tire forces that guarantee the equilibrium. A yaw moment analysis is performed to identify the contributions of the longitudinal and lateral forces. The results show a good agreement between the classical and new formulations of the understeer coefficient, and allow to infer a relationship between the understeer coefficient and the yaw moment analysis. The handling characteristics vary with speed and front-to-rear wheel torque distribution. An apparently surprising result arises at low speed: the RWD architecture is the most understeering configuration. This is discussed by analyzing the yaw moment caused by the longitudinal forces of the front tires, which is significant for high values of lateral acceleration and steering angle. 相似文献
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F. Bucchi F. Frendo 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(6):831-847
The handling behaviour of vehicles is an important property for its relation to performance and safety. In 1970s, Pacejka did the groundwork for an objective analysis introducing the handling diagram and the understeer coefficient. In more recent years, the understeer concept is still mentioned but the handling is actively managed by direct yaw control (DYC). In this paper an accurate analysis of the vehicle handling is carried out, considering also the effect of drive forces. This analysis brings to a new formulation of the understeer coefficient, which is almost equivalent to the classical one, but it can be obtained by quasi-steady-state manoeuvres. In addition, it relates the vehicle yaw torque to the understeer coefficient, filling up the gap between the classical handling approach and DYC. A multibody model of a Formula SAE car is then used to perform quasi-steady-state simulations in order to verify the effectiveness of the new formulation. Some vehicle set-ups and wheel drive arrangements are simulated and the results are discussed. In particular, the handling behaviours of the rear wheel drive (RWD) and the front wheel drive (FWD) architectures are compared, finding an apparently surprising result: for the analysed vehicle the FWD is less understeering than for RWD. The relation between the yaw torque and the understeer coefficient allows to understand this behaviour and opens-up the possibility for different yaw control strategies. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(2):179-193
The sporting spirit that characterises a high-performance car can be observed in certain technical solutions. The power distribution on the rear wheels is the simplest example of that. It is well known that rear-wheel drive (RWD) vehicles are more fun to drive and faster in their reactions. Unfortunately, they are also less intuitive and harder to control because of their natural oversteering behaviour. The idea of maintaining an RWD driveline in the future is not farseeing, because it would imply an excessive tyre dimension increasing to let the driver use all engine power in many cornering and low-friction conditions. The choice of adopting a part-time all-wheel drive (AWD) driveline comes from the will of enhancing the overall performance by using all the available friction every time that it is needed. It has to be kept into account that a normally aspirated motor of a sport car can supply 500–600 Hp nowadays, and that it will supply 700–800 Hp in the very near future. However, the proposed driveline has not to worsen the weight characteristics (mass and load distribution) that make an RWD vehicle better than other cars. Because of all these considerations and constraints, a new driveline system has been designed. It derives from an RWD driveline with a semi-active differential, to which has been added a controlled wet clutch that directly connects the engine to the front differential. This device allows the drive torque to be distributed between the two axles. It can be understood that in such a device, the torque distribution does not depend only on the central clutch action, but also on the engaged gear. Because of this particular layout, this system can not work in the whole gear range because of thermal problems due to kinematical reasons. So the centre clutch controller has to consider the gear position too. The control algorithms development was carried out using a vehicle model, which can precisely simulate the handling response, the powertrain dynamic, and the actuation system behaviour. Such a modelling precision required the development of a customised powertrain model library in Matlab/Simulink. 相似文献
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考虑路面不平度的汽车稳定性控制的研究 总被引:8,自引:1,他引:8
考虑路面不平度对汽车稳定性的影响,建立了一个含路面不平度激励的14自由度的汽车动力学模型。在主动悬架技术的基础上,运用直接的反馈控制制定了提高汽车操纵稳定性的控制策略。利用该模型进行了汽车稳定性的仿真研究。与没有稳定性控制系统的仿真结果相比,该控制器的应用能够较好地改善汽车的稳定性。 相似文献