基于改进模糊PID控制的EPS系统建模仿真

电动助力转向(EPS)是一种新型的汽车动力转向技术。为了提高系统的响应速度、控制精度、实时性等,分析了EPS系统的工作原理,结合EPS的结构和动力学特性,建立了EPS的数学模型。在模糊PID控制基础上,提出了一种将单纯性法与模糊PID控制相结合的改进模糊PID控制方法,并在MATLAB平台上建立了EPS系统仿真模型。仿真结果表明,方法明显改善了系统的瞬态响应和随从特性,具有良好的转向灵活性和操纵稳定性。     

基于程序升温法保留时间预测的气-质联用系统构建虚拟实验室

在气-质联用技术的理论研究及实验的基础上,采用Flash 8.0和ActionScript 2.0编程技术构建开放式网络气-质联用系统虚拟实验室。以若干有机物为考察对象,根据程序升温色谱法(PTGC)中保留值与温度及流速的关系,构建了不同色谱分析条件下保留参数的预测模型,同时利用Flash组件技术,构建与虚拟实验配套的气-质联用系统虚拟工作站。     

一种基于双线性链表结构编码的遗传算法

针对基于以往经典编码方式的遗传算法解决并行机大批量成组调度问题时的弊端,提出了一种基于双线性链表结构编码的遗传算法（DLGA）,并设计了相应的遗传算子。应用于某轮胎厂的硫化工序调度问题,进行了仿真分析。     

飞机分布式配电系统总线监控器的设计

对基于MIL-STD-1553B多路传输数据总线先进飞机的分布式配电系统的结构和功能进行了分析,重点论述了总线监控器的功能及应用软件的设计及实现;配电系统的消息数量多而且传输频率高,因此如何实现实时监控消息是软件设计的关键;采用Windows消息驱动机制和多线程概念,并结合实时内存数据库技术,很好地解决了实时问题;总线通信试验表明,系统运行可靠,达到了功能要求,具有很好的监控效果,可用于分布式配电系统中。     

考虑EV充放电意愿的园区综合能源系统双层优化调度

随着电动汽车的普及度越来越高,工业园区的电动汽车用户日益增多,其充放电行为对园区综合能源系统规划和运行带来极大挑战。本文提出了考虑电动汽车充放电意愿的园区综合能源系统双层优化调度。首先基于动态实时电价、电池荷电量、电池损耗补偿、额外参与激励等因素建立充放电意愿模型,在此基础上得到改进的电动汽车充放电模型;然后,以园区综合能源系统总成本最小和电动汽车充电费用最小为目标建立双层优化调度模型,通过KKT条件将内层模型转化为外层模型的约束条件,从而快速稳定的实现单层模型的求解;最后,进行仿真求解,设置3种不同场景,对比了所提模型与一般充放电意愿模型,验证了文中所提引入EV充放电意愿模型的园区综合能源系统双层优化调度的有效性和可行性,具有一定的经济效益。     

超声冲击诱发表面纳米化及其对表面完整性的影响

采用不同超声冲击参数处理SMA490BW钢,研究了冲击后试样在低、高倍下的微观组织特征、残余应力及硬度分布等表面完整性能的变化。实验结果表明,经过超声冲击表面处理后,样品表面层晶粒细化为纳米晶,平均晶粒尺寸约为30nm;并在试样表层引入残余压应力,数值最大约为255.5MPa;超声冲击对SMA490BW钢表面能够起到明显的强化作用,与未经处理的试样相比,处理后试样表面硬度最大提高了约66.7%。超声冲击强化处理改善SMA490BW钢的表面完整性的效果与冲击电流、冲击时间之间的关系不遵循单调变化规律,超声冲击参数为20min/1.5A时,试样具有较好的表面完整性,冲击影响层深度约为320μm。     

A facile synthesis of supported amorphous iron oxide with high performance for Cr(Ⅵ) removal from aqueous solution under visible light irradiation

A series of supported iron oxide nanoparticles were prepared by impregnation with Fe(NO_3)_3 supported on TiO_2,followed by low-temperature calcination. Scanning electron microscopy(SEM), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), UV–vis diffuse reflectance spectra and BET have been used to characterize the samples. These iron oxide-impregnated TiO_2 were examined for photocatalytic reduction of Cr(Ⅵ). The experiments demonstrated that Cr(Ⅵ) in aqueous solution was more efficiently reduced using Fe_2O_3/TiO_2 heterogeneous photocatalysts than either pure Fe_2O_3 or TiO_2 under visible light irradiation. All TiO_2 supported samples were somewhat active for visible light photoreduction. With an optimal mole ratio of 0.05-Fe/Ti, the highest rate of Cr(Ⅵ) reduction was achieved under the experimental conditions. We also compared the photoreactivity of TiO_2 supported iron oxide samples with that supported on Al_2O_3 and ZrO_2. It can be noted that iron oxide nanoparticles deposited on high surface area supports to increase the solid-liquid contact area renders it considerably more active. Noticeably,iron oxide cluster size and dispersion are important parameters in synthesizing active, supported Iron oxide nanoparticles. In addition, the interaction between iron oxide and TiO_2 was proposed as the source of photoactivity for Cr(Ⅵ) reduction.     

The establishment of edge-based loop algebra theory of kinematic chains and its applications

Based on the edge-based array representation of loops in the topological graphs of kinematic chains, this paper first proposes three arithmetic operations of loops. Then the concept of the independent loop set as well as its determination rules is introduced, and a new structure decomposition algorithm of kinematic chains is presented. Based on the algorithm, an automatic and efficient method for rigid sub-chain detection and driving pair selection of kinematic chains is proposed. Finally, an index is proposed to assess computation complexity of kinematic analysis with respect to different driving pair selections.