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691.
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
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693.
含弱面岩质路堑边坡开挖坡角优化设计方法及应用 总被引:1,自引:0,他引:1
根据含软弱面岩质边坡的岩体结构特点,概化出含弱面岩质路堑边坡开挖坡角优化模型。建立了基于极限平衡方法的计算含软弱面岩质边坡最优开挖坡角的方法。将这种方法运用于某公路路堑高边坡的实践中,确定了影响其最优开挖坡角因素并确定了正交试验方案表,采用正交试验对各因素进行了敏感性分析,确定了该公路含弱面岩质路堑边坡的最优开挖坡角的合理取值范围,最后通过对该公路边坡实例的分析,证明这种计算模型作为一种计算最优开挖坡角简便途径的有效性和实用性。 相似文献
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697.
Vehicle dynamics integrated control for four-wheel-distributed steering and four-wheel-distributed traction/braking systems 总被引:2,自引:0,他引:2
E. Ono Y. Hattori Y. Muragishi K. Koibuchi 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(2):139-151
In this article, vehicle dynamics integrated control algorithm using an on-line non-linear optimization method is proposed for 4-wheel-distributed steering and 4-wheel-distributed traction/braking systems. The proposed distribution algorithm minimizes work load of each tire, which is controlled to become the same value. The global optimality of the convergent solution of the recursive algorithm can be proved by extension to convex problems. This implies that theoretical limited performance of vehicle dynamics integrated control is clarified. Furthermore, the effect of this vehicle dynamics control for the 4-wheel-distributed steering and 4-wheel-distributed traction/braking systems is demonstrated by simulation to compare with the combination of the various actuators. 相似文献
698.
介绍了一种整体式转向梯形机构的空间运动学分析方法,并利用该方法计算了某轻型货车的前轴内、外轮转角关系,计算结果与实测的该车前轴内、外轮转角关系曲线吻合较好。应用不同的整体式转向梯形机构的平面分析方法对同一辆货车进行了分析,对所得分析结果与试验结果进行比较,结果表明我国目前采用较多的汽车设计教材中介绍的转向梯形分析方法误差较大。 相似文献
699.
铰接车辆转向侧翻过程仿真 总被引:2,自引:1,他引:2
建立了铰接式车辆转向侧翻过程的数学模型,根据铰接式车辆在转向侧翻过程中的一些重要特性,研究和分析了铰接车辆侧翻的影响参数,通过过程仿真,获得了实现铰按车辆安全转向的车速临界值. 相似文献
700.
本文推导出断开式转向梯形的左,右转向轮转角计算公式。提示出对实际转向特性曲线有影响的因素,并详细分析各因素对该特性曲线的影响。 相似文献