半主动悬架的无迹卡尔曼状态观测器设计

卡尔曼滤波器是线性动态系统中应用最广泛的一种状态估计方法。在非线性系统中,扩展卡尔曼滤波(EKF)和无迹卡尔曼滤波(UKF)被广泛应用,相比扩展卡尔曼滤波器,无迹卡尔曼滤波器准确度更高、更易于实现。在车辆动力学这种强的非线性系统中,无迹卡尔曼滤波器应用广泛。设计了一种基于无迹卡尔曼滤波器的半主动悬架系统状态观测器,讨论了不准确的过程噪声协方差Q和测量噪声协方差R、及测量信号组合的选择和不准确的模型参数对状态观测精度的影响,仿真结果表明不准确的过程噪声和测量噪声协方差、不合适的测量信号选择和模型参数不准确的干扰在不同程度上降低了状态估计精度。     

基于HPLC指纹图谱与多元统计分析的太平猴魁产地判别方法

以核心产地和非核心产地的太平猴魁为研究对象,通过优化高效液相色谱(HPLC)检测方法建立太平猴魁HP LC指纹图谱,并结合多元统计分析方法对不同产地太平猴魁样品进行鉴别分析.结果表明:按优化后的HP LC检测方法对核心产地10种太平猴魁样品进行定量分析,共鉴定出11个共有峰(GA、5-GC、GC、TB、EGC、Cat、...     

基于刚柔耦合的双横臂前悬架性能分析

运用ADAMS／Car对某前悬架进行建模,生成模态中性文件;在ADAMS／Car中调用该文件建立刚柔耦合双横臂前悬架,对该前悬架系统进行运动学和柔性运动学仿真,并分析该悬架特性。结果表明：车轮前束和轮距均未达到理想的状况,对此提出了相应的优化方案。此外,通过对比分析柔性对该型悬架的性能影响,发现刚柔耦合双横臂前悬架相比刚性悬架能够更加准确地反映前悬架的实际性能。     

某自卸车下兜梁分析及改进

针对实际中某型自卸车兜梁故障率比较高的情况,将兜梁放入到整车环境中进行弯扭工况的有限元分析,并对兜梁结构进行改进设计。对比改进前后的分析结果可知,改进后的兜梁明显优于原兜梁,改进方案是合理有效的。     

三种烤烟育苗方式的成苗素质及育苗成本的研究

研究了改进式漂浮育苗、常规漂浮育苗和浅水育苗3种育苗方式的成苗素质和育苗成本.结果表明,改进式漂浮育苗的烟苗素质明显优于浅水育苗和常规漂浮育苗,成本相对较低,具有良好的经济效益.因此,选用改进式漂浮育苗替代常规漂浮育苗和浅水育苗是必要而且可行的.     

Research on the Peristaltic Flow Acceleration Performance of Asynchronous and Duty Cycle Pulsed DBD Plasma Actuation

Using a plexiglas plate model, the performance of peristaltic flow acceleration in- duced by multiple DBD （dielectric barrier discharge） plasma actuators was studied based on PIV （particle image velocimetry）. The asynchronous and the duty cycle pulsed actuation modes were proposed and tested. The velocity fields induced by multiple DBD plasma actuators with different phase angles and duty cycle ratios were acquired and the momentum transfer characteristics of the flow field were discussed. Consequently, the mechanism of the peristalsis-acceleration multi- ple DBD plasma actuation was analyzed. The results show that the peristaltic flow acceleration effect of multiple plasma actuators occurs mainly in paraelectric direction, and the mechanism of peristaltic flow acceleration is ejection pushing effect rather than injection pumping effect. The asynchronous and the duty cycle pulsed actuation modes can, with energy consumption increase of merely 10%, achieve 65% and 42% increase of downstream velocity, and thus are promising in velocity improvement and energy saving.     

Turbulent boundary layer control with DBD plasma actuators

The flat-plate turbulent boundary layer at Reτ= 1140 is manipulated using a spanwise array of bidirectional dielectric barrier discharge(DBD) plasma actuators. Based on the features of no moving mechanical parts in the DBD plasma control technology and hot-wire anemometer velocity measurements, a novel convenient method of local drag reduction(DR) measurement is proposed by measuring the single-point velocity within the linear region of the viscous sublayer. We analyze the premise of using the m...     

施氯量对烤烟生长及品质的影响

为探讨烤烟适宜的施氯量,研究了不同施氯量对烤烟生长和品质的影响。结果表明,施氯量为45 kg/hm2时烤烟株高增加率极显著高于其他处理,施氯量为30 kg/hm2时烤烟最大叶面积和叶宽增加率显著高于其他处理;总糖含量和两糖差随施氯增加而升高,施氯后各处理烟叶总氮含量均显著低于对照组,且烟碱含量呈降低趋势;施氯量在30~45 kg/hm2时能有效促进烟叶生长发育,叶绿素既能大量合成也能在后期充分降解,降低烟叶含氮化合物含量,抑制烟碱合成,增加烟叶含糖量,有利于提高烟叶评吸质量。