基于CAN网络的混合动力汽车硬件在环仿真平台

建立基于多xPC-Target系统的混合动力汽车硬件分布式实时在环仿真平台.通过CAN网络将2个xPC-Target双机系统组合而成.2个xPC-Target双机系统各自运行混合动力汽车各个功能模块的仿真模型,实现数据采集、处理及计算.使用多个xPC-Target系统能够有效分担仿真硬件设备的计算量,有利于提高仿真模型复杂度,提高仿真精度.由CAN网络实现2个xPC-Target系统间的通信.对xPC-Target的性能进行了测试,对CAN通信的时延进行了测试.在所构建的仿真平台上进行的计算验证了仿真平台的可靠性.     

基于整车的半主动油气悬架滑模控制研究

以提高平顺性为目的,针对油气悬架整车设计了以天棚阻尼为参考模型的滑模控制系统,对4个悬架的阻尼力分别进行控制,建立了非线性半主动油气悬架的七自由度整车模型,使被控车辆振动响应能够跟随参考模型.在Matlab环境中对滑模控制系统的性能进行了验证,仿真车辆以54km/h的速度行驶于D级路面,与被动油气悬架相比,模型参考滑模控制系统能够有效衰减簧载质量的垂向振动、俯仰振动和侧倾振动.结果表明,基于油气悬架整车的模型参考滑模控制系统对路面激励和车辆参数变化具有较强的鲁棒性,适合应用于非线性油气悬架阻尼控制.     

汽车状态感知系统的Android客户端

随着汽车数量的日益增多,为了合理调度车辆、为车辆选择最佳行车路线、对车辆故障提前预警,如何更加方便、可靠地获取汽车的实时状态信息,已成为迫切需要解决的问题。该文针对以上问题设计了运行在Android手机操作系统上的汽车状态感知系统的客户端,通过手机蓝牙对汽车状态数据进行采集,同时获取GPS位置信息,通过3G网络实时的将这些数据上传服务器,实现了状态实时显示、历史旅程查看等功能。该系统可以替代昂贵的车载终端,有效地降低汽车状态感知的成本;通过手机作为通信终端使其具有良好的可扩展性和灵活性,使用3G网络具有高带宽、低延迟、可靠性高等特点。通过实际的运行测试该系统可以实时地获取汽车状态信息,可以使监控中心对车辆的故障进行预警,还可以优化车辆的调度。     

中国乘用车与商用车保有量预测

为了获得中国未来汽车保有量及其构成,分别采用Gompertz模型和线性外推模型对中国的乘用车和商用车保有量进行了预测。结果表明:中国汽车保有量在2020年和2030年将分别达到2.5—2.9亿辆和4—5.2亿辆,其中乘用车保有量增长速度相对较快,且存在一定不确定性,在2020年和2030年将分别达到2.2—2.6亿辆和3.5—4.8亿辆。商用车保有量在2020年和2030年将分别达到0.33和0.47亿辆。在2030年之前,中国汽车保有率将快速提高,但是相比发达国家将始终有较大差距。     

全隐式E-CUSP迎风格式大攻角分离流数值模拟

采用全隐式、低耗散E-CUSP格式,通过求解雷诺平均Navier-Stokes方程耦合Spalart-Allmaras(SA)湍流模型,模拟了细长旋成体在超声速、大攻角下的流场,分析了背风面涡的发展过程.结果表明:E-CUSP格式耦合SA湍流模型能够准确地模拟背风面的流动分离和精细的二次涡,对横向分离具有较高的模拟精度;预测的物面压力系数分布和激波位置与实验数据吻合良好,力和力矩的相对误差在1.98%之内;E-CUSP格式可用于模拟复杂的分离流动,具有高的计算精度和效率.     

有时间窗约束非满载车辆调度问题的节约算法

车辆调度问题(Vehicle Routing Problem,简称为VRP)是物流配送中广泛存在的一类问题,VRP属于强NP问题.在建立了带有时间窗的非满载的VRP问题的数学模型基础上,对启发式算法中的节约算法进行改进,设计出带时间窗的非满载的VRP问题的节约算法.通过对8个客户和13个客户算例的具体计算结果分析该算法的性能,研究表明:节约算法具有易于计算机实现,易于调整,方法易行、效果理想等优点,但在客户规模增加,解的空间增加后,其解的精度也随之下降.     

Unobserved components in ARCH models: An application to seasonal adjustment

The paper deals with unobserved components in ARIMA models with GARCH errors, in the context of an actual application, namely seasonal adjustment of the monthly Spanish money supply series. The series shows clear evidence of (moderate) non-linearity, which does not disappear with simple outlier correction. The GARCH structure explains reasonably well the non-linearity, and this explanation is robust with respect to the GARCH specification. We look at the time variation of the standard error of the adjusted series estimator and show how it can be measured. Next, we look at the implications this variation has on short-term monetary control. The non-linearity seems to have a small effect in practice. It is further seen that the conditional variance of the GARCH process may, in turn, be decomposed into components. In fact, the conditional variance of the money supply series is the sum of a weak linear trend, a strong non-linear seasonal component, and a moderate non-linear irregular component. This information has policy implications: for example, there are periods in the year when policy can be more assertive because information is more precise. Finally, looking at the non-linear components of the money supply it is seen how linear combinations of non-linear series can produce series that behave linearly.     

Forecasting the Antwerp maritime traffic flows using transformations and intervention models

This article uses univariate time-series models with data transformations and intervention models to forecast the volumes of twenty-two maritime traffic flows in the port of Antwerp which are expressed in tonnes. The models obtained produce forecasts that are a substantial improvement over those obtained with unadjusted data. The models also provide useful insight into the behaviour of maritime traffic flows during the period 1971–82.     

Existence of macroscopic spatial superpositions in collapse theories

It is shown that the collapse dynamics in the CSL model will entangle two independent systems under certain conditions, and their state after collapse may be an entangled superposition of spatially separated states. However, since the conditions can hardly be satisfied in reality, the occurrence of such superpositions is very improbable, and thus collapse theories still provide a promising solution to the measurement problem.     

多无人机协同探测快速目标的控制方法设计

针对无人机(unmannd aerial vehicle, UAV)对快速运动目标的协同探测问题, 设计了一种多UAV协同探测控制算法。首先假设每架UAV都携带相同的探测载荷, 根据载荷特性设计了针对快速运动目标的UAV协同探测队形。然后引入固定时间控制一致性协议到UAV载荷角度控制中, 控制载荷持续照射目标; 引入有限时间一致性协议到UAV编队控制中, 用以形成协同探测队形, 并通过二跳网络加快队形的收敛。通过将UAV队形控制与UAV载荷的角度控制相结合, 从而实现UAV对快速运动目标探测时间的最大化, 极大的延长了高速运动目标被发现的时间。最终通过理论分析和仿真实验证明了该控制算法的有效性。