共查询到19条相似文献,搜索用时 667 毫秒
1.
2.
3.
给出3自由度角输入避让转向驾驶员-汽车闭环模型,采用均匀设计方法安排汽车在高速下进行双移线避让试验,通过组合驾驶员模型中三个不同参数对闭环模型进行正解得到用于RBF网络的训练样本,建立汽车横摆角速度、侧向加速度及车身侧倾角与转向盘转角及角速度的映射关系。所建立的RBF网络能以汽车横摆角速度、侧向加速度及车身侧倾角共同识别转向盘转角及角速度,仿真结果表明该方法具有运算速度快、识别精度高等优点。 相似文献
4.
为客观评价不同驾驶员的弯道操纵能力,提出了一种驾驶员弯道行驶过程操纵行为实车测试分析方法。招募12名驾驶员在试验场标准路面上进行实车试验,分别以30 km/h、40 km/h、50 km/h的初速度驶入U形弯道并自由行驶,记录驾驶员操控数据和车辆运动状态数据,对驾驶员弯道操纵能力进行分析。试验结果表明:不同能力的驾驶员在纵向车速、纵向加速度、纵向急动度、转向盘转角、横摆角速度、转向盘转角熵值等指标上呈现明显差异。该方法可进一步扩展应用于自动驾驶汽车的弯道行驶能力分析评估。 相似文献
5.
中重型柴油汽车的操纵稳定性研究的内容很多,诸如转向轮稳定力矩,悬架结构对行驶方向稳定性的影响,轮胎受力变形的规律,柴油汽车按驾驶意图行驶的能力(如改变行驶路线躲避障碍的能力、抗侧滑能力、抗侧向偏移能力、抗侧向风吹袭的能力)等.不过,对于载货汽车来说更注重柴油汽车的转向性能.转向性能是讨论柴油汽车的转向轮转角、转弯半径和车速之间的关系. 相似文献
6.
汽车的力学参数与稳态转向特性 总被引:2,自引:0,他引:2
本文以汽车力学参数试验台测出的数据为基础,为通过建立轮胎侧偏角,车厢侧倾角,回正力矩与侧向加速度之间的关系,运用最小二乘法对测试数据进行线性曲线拟合,找出了这些数据与汽车记转向特性之间的关系,并按国家标准GB/T3047-91中的有关规定对被测试车辆的稳态转向特性进行了评价 。 相似文献
7.
为了提高汽车的操纵稳定性和行驶稳定性,分别对主动转向及直接横摆力矩控制进行了研究。根据汽车线性二自由度模型获得汽车稳态工况下的期望横摆角速度和期望质心侧偏角,设计了上层控制器和下层控制器,其中上层控制器为主动转向与直接横摆力矩功能分配的协调控制,下层控制器采用单神经元自适应PID算法设计了主动转向控制器和直接横摆力矩控制器。基于汽车行驶稳定性指标设计了调度参数,以实现主动转向和直接横摆力矩的协调控制。分别选取高附着系数路面和低附着系数路面进行了正弦输入试验和阶跃输入试验,结果表明所设计的控制系统能够很好地提高线控转向汽车的操纵稳定性和行驶稳定性。 相似文献
8.
四轮转向的基本结构与发展 总被引:2,自引:0,他引:2
汽车的四轮转向系统在80年代中期开始发展,其主要目的是提高汽车在高速行驶或在侧向风力作用下时的操纵稳定性、改善低速时的操纵轻便性,以及减小在停车场调车时的转弯半径。此外,在汽车高速行驶时还易于由一个车道向另一个车道的调整。四轮转向系统可按后轮偏转角与前轮偏转角或车速之间的关系分为转角传感型与车速传感型两种: 相似文献
9.
10.
基于主动横向稳定杆的汽车防侧翻控制 总被引:1,自引:0,他引:1
为了提高汽车转向时的侧向稳定性,建立了汽车三自由度侧翻模型,提出了主动横向稳定杆直接防侧翻力矩控制的汽车侧向稳定性控制方案。采用LQR最优控制算法,以侧向加速度、质心侧偏角和横向载荷转移率为综合控制对象,以主动横向稳定杆为执行机构,建立防侧翻控制系统,在Matlab/Simulink环境中对汽车进行阶跃转向侧翻仿真实验。仿真结果表明,基于主动横向稳定杆LQR控制系统能够及时在横向稳定杆上产生抗侧翻力矩,提高汽车的转向侧翻控制能力,减少侧翻事故的发生。 相似文献
11.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):522-538
This paper presents an investigation about influencing the driver's behaviour intuitively by means of modified steering feel. For a rollover indication through haptic feedback a model was developed and tested that returned a warning to the driver about too high vehicle speed. This was realised by modifying the experienced steering wheel torque as a function of the lateral acceleration. The hypothesis for this work was that drivers of heavy vehicles will perform with more margin of safety to the rollover threshold if the steering feel is altered by means of decreased or additionally increased steering wheel torque at high lateral acceleration. Therefore, the model was implemented in a test truck with active steering with torque overlay and used for a track test. Thirty-three drivers took part in the investigation that showed, depending on the parameter setting, a significant decrease of lateral acceleration while cornering. 相似文献
12.
13.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1149-1168
Vehicle steering dynamics show resonances, which depend on the longitudinal speed, unstable equilibrium points and limited stability regions depending on the constant steering wheel angle, longitudinal speed and car parameters. The main contribution of this paper is to show that a combined decentralized proportional active front steering control and proportional-integral active rear steering control from the yaw rate tracking error can assign the eigenvalues of the linearised single track steering dynamics, without lateral speed measurements, using a standard single track car model with nonlinear tire characteristics and a non-linear first-order reference model for the yaw rate dynamics driven by the driver steering wheel input. By choosing a suitable nonlinear reference model it is shown that the responses to driver step inputs tend to zero (or reduced) lateral speed for any value of longitudinal speed: in this case the resulting controlled vehicle static gain from driver input to yaw rate differs from the uncontrolled one at higher speed. The closed loop system shows the advantages of both active front and rear steering control: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres, enlarged stability regions, reduced lateral speed and improved manoeuvrability; in addition comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced. For the designed control law a robustness analysis is presented with respect to system failures, driver step inputs and critical car parameters such as mass, moment of inertia and front and rear cornering stiffness coefficients. Several simulations are carried out on a higher order experimentally validated nonlinear dynamical model to confirm the analysis and to explore the robustness with respect to unmodelled dynamics. 相似文献
14.
Riccardo Marino Stefano Scalzi Fabio Cinili 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2007,45(12):1149-1168
Vehicle steering dynamics show resonances, which depend on the longitudinal speed, unstable equilibrium points and limited stability regions depending on the constant steering wheel angle, longitudinal speed and car parameters.
The main contribution of this paper is to show that a combined decentralized proportional active front steering control and proportional-integral active rear steering control from the yaw rate tracking error can assign the eigenvalues of the linearised single track steering dynamics, without lateral speed measurements, using a standard single track car model with nonlinear tire characteristics and a non-linear first-order reference model for the yaw rate dynamics driven by the driver steering wheel input. By choosing a suitable nonlinear reference model it is shown that the responses to driver step inputs tend to zero (or reduced) lateral speed for any value of longitudinal speed: in this case the resulting controlled vehicle static gain from driver input to yaw rate differs from the uncontrolled one at higher speed. The closed loop system shows the advantages of both active front and rear steering control: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres, enlarged stability regions, reduced lateral speed and improved manoeuvrability; in addition comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced.
For the designed control law a robustness analysis is presented with respect to system failures, driver step inputs and critical car parameters such as mass, moment of inertia and front and rear cornering stiffness coefficients. Several simulations are carried out on a higher order experimentally validated nonlinear dynamical model to confirm the analysis and to explore the robustness with respect to unmodelled dynamics. 相似文献
The main contribution of this paper is to show that a combined decentralized proportional active front steering control and proportional-integral active rear steering control from the yaw rate tracking error can assign the eigenvalues of the linearised single track steering dynamics, without lateral speed measurements, using a standard single track car model with nonlinear tire characteristics and a non-linear first-order reference model for the yaw rate dynamics driven by the driver steering wheel input. By choosing a suitable nonlinear reference model it is shown that the responses to driver step inputs tend to zero (or reduced) lateral speed for any value of longitudinal speed: in this case the resulting controlled vehicle static gain from driver input to yaw rate differs from the uncontrolled one at higher speed. The closed loop system shows the advantages of both active front and rear steering control: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres, enlarged stability regions, reduced lateral speed and improved manoeuvrability; in addition comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced.
For the designed control law a robustness analysis is presented with respect to system failures, driver step inputs and critical car parameters such as mass, moment of inertia and front and rear cornering stiffness coefficients. Several simulations are carried out on a higher order experimentally validated nonlinear dynamical model to confirm the analysis and to explore the robustness with respect to unmodelled dynamics. 相似文献
15.
《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
16.
通过台车试验,对受方向盘角度影响和座椅刚度等影响下的几种典型的胸部伤害情况进行了分析研究,指出了在无安全气囊或气囊作用偏弱的情况下,方向盘的水平角度一般时容易造成胸部加速度偏大,方向盘水平角度偏大时容易造成胸部压缩变形量偏大;另外,也指出了碰撞中,坐垫的深度偏大和前端刚度偏强时容易增大假人胸部伤害,坐垫前端刚度偏弱时导致假人下沉可造成胸部伤害指标提高,这为约束系统的匹配提供了参考。 相似文献
17.
Y. G. Cho 《International Journal of Automotive Technology》2009,10(4):431-439
In this paper, an analytical model with suitable vehicle parameters, together with a multi-body model is proposed to predict
steering returnability in low-speed cornering with what is expected to be adequate precision as the steering wheel moves from
lock to lock. This model shows how the steering response can be interpreted in terms of vertical force, lateral force with
aligning moment, and longitudinal force. The simulation results show that vertical steering rack forces increase in the restoring
direction according to steering rack displacement for both the inner and outer wheels. As lateral forces due to side-slip
angle are directed toward the medial plane of the vehicle in both wheels, the outer wheel pushes the steering wheel in the
returning direction while the inner wheel does not. In order to improve steering returnability, it is possible to increase
the total steering rack force in both road wheels through adjustments to the kingpin axis and steering angle. This approach
is useful for setting up a proper suspension geometry during conceptual chassis design. 相似文献
18.
介绍了一种考虑轮胎侧偏影响的车轮内外角关系研究的方法,并通过试验分析了车轮内外轮的转角关系变化,同时使用该方法对车轮转角关系进行了分析。结果表明,在小转角的时候,百分比阿克曼校正率在合理范围内,随着转角增大该值逐步增大,轮胎内外轮侧偏角的差值也逐渐增大,使得轮胎磨损趋势增加。 相似文献