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为了研究转向横拉杆的弹性对车辆操纵稳定性的影响,利用ADAMS软件建立了某轿车的多体动力学模型并进行了操纵稳定性的仿真分析。对于操纵稳定性的稳态特性,采用了ISO4138标准,在车辆行驶100 km/h下的固定圆周转向规程来进行评价;对于瞬态操纵稳定性特性,则采用ISO7401标准中方向盘扫频输入的响应特性来进行评价。仿真结果表明,转向横拉杆的弹性与轿车操纵稳定性的不足有很大关系,如果弹性横拉杆刚性过大,则需要1个较大的转向传动比以弥补其不足转向特性。因此,在汽车设计开发中,必须将转向横拉杆的弹性特性和转向传动比综合平衡考虑,两需要很好的匹配才能保证其具有良好的操纵稳定性。 相似文献
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在充分考虑侧倾对汽车操纵稳定性影响的情况下,建立起基于横向动力学的整车模型,并进行了汽车稳态转向特性的仿真研究。 相似文献
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在建立汽车线性二自由度模型的基础上,将汽车系统简化为一般的二阶控制系统,分析汽车前轮角输入的响应,主要包括稳态响应和瞬态响应;结合具体车型参数,提出了表征汽车稳定性的关键参数的计算方法,为汽车操纵稳定性提供实际的分析方法。 相似文献
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轮胎附着极限下差动制动对汽车横摆力矩的影响 总被引:20,自引:3,他引:20
本文以纵滑-侧偏联合工况的稳态轮胎模型为基础,分析了汽车极限转向条件下制动作用于不同车轮时对汽车横摆力矩的影响,并通过整车动力学仿真进行了验证,研究结果为利用差动制动控制提高汽车的高速操纵稳定性提供了动力学依据。 相似文献
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运用多体动力学软件ADAMS/Car建立某半挂汽车列车虚拟试验整车模型,参照汽车操纵稳定性试验方法对该半挂汽车列车进行转向瞬态响应试验仿真,分析得到了半挂汽车列车在不同速度下的侧向加速度和横摆角速度响应、转向瞬态响应试验的极限车速及半挂汽车列车安全运行的最大侧倾角,为半挂汽车列车的设计和使用提供理论依据. 相似文献
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本文对汽车半挂列车的稳态转向特性进行了研究和分析;提出了评价方法,并得到了试验验证;它对汽车半挂列车操纵稳定性的研究和如何设计好汽车半挂列车的行驶方向稳定性有参考价值。 相似文献
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Rollover mitigation for a heavy commercial vehicle 总被引:1,自引:0,他引:1
Y. I. Ryu D. O. Kang S. J. Heo J. H. In 《International Journal of Automotive Technology》2010,11(2):283-287
A heavy commercial vehicle has a high probability of rollover because it is usually loaded heavily and thus has a high center
of gravity. An anti-roll bar is efficient for rollover mitigation, but it can cause poor ride comfort when the roll stiffness
is excessively high. Therefore, active roll control (ARC) systems have been developed to optimally control the roll state
of a vehicle while maintaining ride comfort. Previously developed ARC systems have some disadvantages, such as cost, complexity,
power consumption, and weight. In this study, an ARC-based rear air suspension for a heavy commercial vehicle, which does
not require additional power for control, was designed and manufactured. The rollover index-based vehicle rollover mitigation
control scheme was used for the ARC system. Multi-body dynamic models of the suspension subsystem and the full vehicle were
used to design the rear air suspension and the ARC system. The reference rollover index was tuned through lab tests. Field
tests, such as steady state cornering tests and step steer tests, demonstrated that the roll response characteristics in the
steady state and transient state were improved. 相似文献
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J. A. Mohrfeld-Halterman 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(7):963-981
We described in this paper the development of a high fidelity vehicle aerodynamic model to fit wind tunnel test data over a wide range of vehicle orientations. We also present a comparison between the effects of this proposed model and a conventional quasi steady-state aerodynamic model on race vehicle simulation results. This is done by implementing both of these models independently in multi-body quasi steady-state simulations to determine the effects of the high fidelity aerodynamic model on race vehicle performance metrics. The quasi steady state vehicle simulation is developed with a multi-body NASCAR Truck vehicle model, and simulations are conducted for three different types of NASCAR race tracks, a short track, a one and a half mile intermediate track, and a higher speed, two mile intermediate race track. For each track simulation, the effects of the aerodynamic model on handling, maximum corner speed, and drive force metrics are analysed. The accuracy of the high-fidelity model is shown to reduce the aerodynamic model error relative to the conventional aerodynamic model, and the increased accuracy of the high fidelity aerodynamic model is found to have realisable effects on the performance metric predictions on the intermediate tracks resulting from the quasi steady-state simulation. 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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Vincenzo Alfieri Giuseppe Conte Carmen Pedicini 《International Journal of Automotive Technology》2018,19(3):405-412
The objective of this study is to investigate a nonlinear model-based multivariable (MIMO, Multi Input Multi Output) technique to decouple actuators interaction and to reduce the calibration effort, while increasing control performances, above all in transient conditions, and robustness with respect to model uncertainties and system parameter variations. The presented control technique is based on the development of a nonlinear dynamical physical model of the diesel air and charging system. Feedback Linearization control is then applied to decouple actuators’ interactions and compensate for nonlinearities. A new set of virtual inputs are defined inverting the system differential equations. Relation among the new virtual inputs and the outputs is purely linear and decoupled, meaning that each virtual input affects linearly only one output. Moreover, a linear control block is added to guarantee transient and steady state performances and closed loop robustness. The proposed control approach has been validated through small diesel engine dyno and vehicle activities. Transient test bench maneuvers show that the control is able to coordinate the actuators in order to fulfill the targets and to guarantee similar performances in different operating points. In addition the robustness to environmental changes has been demonstrated by vehicle tests at different ambient conditions. 相似文献
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Wei Liang Jure Medanic Roland Ruhl 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2008,46(3):197-227
Modeling of tire friction is one of the central problems for vehicle control systems design. LuGre-type dynamic tire model has been proposed and well discussed in previous studies, because it offers a compact form of dynamic model that is convenient in advanced control studies. It has been successfully used in tire slip control design and vehicle state estimation problems. In this article, a concept of time-constrained Stribeck effect is introduced to interpret the mechanism of the LuGre friction model in predicting tire friction characteristics. A modified two-dimensional (2D) dynamic LuGre friction model is introduced to make it compatible with the governing theorem in the steady state. An analytical 2D modified LuGre-type dynamic tire model is developed, in which some fundamental limitations of classical LuGre models are eliminated. The main modifications involve a change in the structure of the 2D LuGre friction model, introduction of load-dependent parameters in 1D and 2D tire models, and a changed structure in the distributed parameter model. The proposed model is compared, in the steady state, to both the Magic Formula and the classical LuGre model. It improves model accuracy in the steady state and gives a physically reasonable distribution of the bristle deflection. A first-order lumped parameter (LP) nonlinear model, which has simpler structure than the distributed parameter model and the classical LP LuGre model, is then derived. Numerical simulations show that the proposed LP model has a good estimation for tire transient dynamics. Thus, the proposed model retains the merits of LuGre-type models and improves the agreement with observation and experimental data on friction force distribution along the patch and on the steady-state friction prediction. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(3):197-227
Modeling of tire friction is one of the central problems for vehicle control systems design. LuGre-type dynamic tire model has been proposed and well discussed in previous studies, because it offers a compact form of dynamic model that is convenient in advanced control studies. It has been successfully used in tire slip control design and vehicle state estimation problems. In this article, a concept of time-constrained Stribeck effect is introduced to interpret the mechanism of the LuGre friction model in predicting tire friction characteristics. A modified two-dimensional (2D) dynamic LuGre friction model is introduced to make it compatible with the governing theorem in the steady state. An analytical 2D modified LuGre-type dynamic tire model is developed, in which some fundamental limitations of classical LuGre models are eliminated. The main modifications involve a change in the structure of the 2D LuGre friction model, introduction of load-dependent parameters in 1D and 2D tire models, and a changed structure in the distributed parameter model. The proposed model is compared, in the steady state, to both the Magic Formula and the classical LuGre model. It improves model accuracy in the steady state and gives a physically reasonable distribution of the bristle deflection. A first-order lumped parameter (LP) nonlinear model, which has simpler structure than the distributed parameter model and the classical LP LuGre model, is then derived. Numerical simulations show that the proposed LP model has a good estimation for tire transient dynamics. Thus, the proposed model retains the merits of LuGre-type models and improves the agreement with observation and experimental data on friction force distribution along the patch and on the steady-state friction prediction. 相似文献
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