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J. Schoeftner W. Ebner 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(12):1865-1883
Automated and manual transmissions are the main link between engine and powertrain. The technical term when the transmission provides the desired torque during all possible driving conditions is denoted as powertrain matching. Recent developments in the last years show that double-clutch-transmissions (DCTs) are a reasonable compromise in terms of production costs, shifting quality, drivability and fuel efficiency. They have several advantages compared to other automatic transmissions (AT). Most DCTs nowadays consist of a hydraulic actuation control unit, which controls the clutches of the gearbox in order to induce a desired drivetrain torque into the driveline. The main functions of hydraulic systems are manifold: they initiate gear shifts, they provide sufficient oil for lubrication and they control the shift quality by suitably providing a desired oil flow or pressure for the clutch actuation. In this paper, a mathematical model of a passenger car equipped with a DCT is presented. The objective of this contribution is to get an increased understanding for the dynamics of the hydraulic circuit and its coupling to the vehicle drivetrain. The simulation model consists of a hydraulic and a mechanical domain: the hydraulic actuation circuit is described by nonlinear differential equations and includes the dynamics of the line pressure and the proportional valve, as well as the influence of the pressure reducing valve, pipe resistances and accumulator dynamics. The drivetrain with its gear ratios, moments of inertia, torsional stiffness of the rotating shafts and a simple longitudinal vehicle model represent the mechanical domain. The link between hydraulic and mechanical domain is given by the clutch, which combines hydraulic equations and Newton's laws. The presented mathematical model may not only be used as a simulation model for developing the transmission control software, it may also serve as a virtual layout for the design process phase. At the end of this contribution a parametric study shows the influence of the mechanical components, the accumulator and the temperature of the oil. 相似文献
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介绍了如何辨认地铁轻轨中常用的整流变压器的接线组别以及二十四脉波的整流原理,并且论述了一种较为简洁接线组别的测试方法。 相似文献
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将牵引计算、牵引控制策略应用到列车运行模拟中,着重从闭塞分区、道岔、临时限速3个方面完善行车模拟。以目前普遍采用的混合控制策略为基础,针对不同行车环境设计相应的列车工况切换策略,再依据牵引计算公式,利用迭代算法获得列车运行数据。最后,利用VC++软件平台实现了列车运行模拟功能。 相似文献
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基于动态规划理论,建立了船厂码头移泊作业问题的动态规划模型.分析了移泊作业的特点,在此基础上建立起问题的动态模型和对应的赋值有向图,把问题转化为求解赋值有向图的最优路问题.依据图论相关知识,对赋值有向图进行改进,从而得到图的最优路,最终求得问题的最优方案.通过实例计算结果与船厂实际操作安排进行比较和分析,得出算法研究的有效性和优越性的结论. 相似文献
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以武汉市白沙洲大道改造大型城市高架桥钻孔灌注桩为实例,主要阐述了在交通量大、房屋密集、上伏流砂层的岩溶地区进行钻孔灌注桩施工时处理溶洞地质病害的方法,为类似工程施工提供借鉴。 相似文献