【作者】 张国林；

【导师】 谢伟东；

【作者基本信息】 浙江工业大学 ， 机械制造及自动化， 2005， 硕士

【摘要】 四轮转向系统的出现是对车辆转向方式的一次革新。四轮转向系统出现于上世纪八十年代,并在实际中得到了应用,理论与实践证明,四轮转向(4WS)技术能有效地提高车辆低速时机动性和高速时的操纵稳定性,具有良好的应用前景。 本文首先介绍了四轮转向技术的发展历程、应用状况和发展前景,并对国内外四轮转向技术的研究状况和控制策略进行了总结介绍。 对车辆的二自由度模型进行了介绍,建立了四轮转向车辆的二自由度线性模型。考虑到车辆悬架的影响,推导了四轮转向车辆的三自由度线性模型。 轮胎的侧偏特性对车辆的操纵稳定性有很大影响,其侧偏特性实际上应表示为一条曲线。对轮胎的各种模型进行了简介,指出了应用神经网络对轮胎的非线性建模的优点。在前人研究的基础上,建立了基于RBF神经网络的车辆轮胎非线性模型,接着推导出考虑轮胎非线性的四轮转向车辆的三自由度非线性模型。 由四轮转向车辆二自由度模型,推导出了前后轮比例控制方式的的四轮转向车辆的传递函数和状态空间方程,对前轮角阶跃输入下的车辆时域特性和频域特性进行了研究与分析,指明了四轮转向技术的更多还原

【Abstract】 Four-wheel-steering system is a huge innovation to vehicle steering methods. It appeared on the eighties of last century, and had many applications in practice. Evidences from theory and practice have proved that four-wheel-steering technique can effectively improve the vehicle low-speed maneuverability and high-speed handling and stability ability. It has good utility prospects.Firstly, this dissertation has introduced the development courses, utility conditions and development prospects of four-wheel-steering technique and has summarized the domestic and international research results and feasible control strategies for four-wheel-steering technique.The dissertation has introduced the 2dof model of the vehicle and set up 2dof linear model of four-wheel-steering vehicle. On account of the influences of chassis on the whole vehicle, a more complicated 3dof linear model of vehicle have been derived of.Sideslip characteristics of tire have big influence on vehicle’s更多还原