共查询到20条相似文献,搜索用时 296 毫秒
1.
2.
3.
4.
介绍了灰色预测模型GM(1,1)的结构和模型检验,以及BP神经网络预测模型的原理,对灰色预测模型进行改良,将此改良模型与BP神经网络模型进行组合,建立了新的组合灰色神经网络模型。以厦门市商品房成交量为例,以MATLAB为工具,进行2012年的成交量对比以及2013年成交量的预测,结果证明组合灰色神经网络的预测精度较高,可以为房地产价格指数预测研究提供参考依据。 相似文献
5.
6.
7.
8.
9.
本文主要研究未来几年内人口数量组成变化的相关问题。对于该问题,我们在灰色GM(1,1)模型的基础上对部分算法进行了优化,考虑到常住人口和流动人口等类型,结合已有的连续5~10午的人口数量,最终给出了人口数量的预测结果。经检验证明,改进的灰色GM(1,1)模型能够有效解决人口数量预测问题。 相似文献
10.
为了达到跟踪预测刀具图像边缘变化趋势的目的,采用了灰色数列GM(1,1)模型预测拟合直线段斜率数列的方法。在分析灰色数列预测模型的基础上,通过建立了图像边缘点拟合直线斜率数列预测模型,并用建立的模型对一帧刀具图像进行边缘趋势预测,将得到的预测结果与实际值进行比较的试验。并以最大误差分析刀具后续边缘点分布趋势,为图像采集平台进给方向提供依据。根据实验结果,得出采用灰色数列模型预测刀具边缘轮廓方法完全满足平台跟踪刀具边缘轮廓要求的结论。 相似文献
11.
基于灰色理论和神经网络建立预测模型的研究与应用 总被引:1,自引:0,他引:1
根据综合利用灰色理论与神经网络建立预测模型的思路,给出了利用神经网络对模型残差进行修正的灰色GM(1,1)模型综合预测方法。选用我国自1994年至2005年狂犬病发病率统计数据,用灰色GM(1,1)模型对历年的疾病发病人数进行建模,并利用LM算法优化的快速BP神经网络对其残差进行修正,使得建模和预测具有更高的准确性和适应性。实验结果及仿真验证表明,加入修正过程的综合模型,其预测效果远优于单一的灰色模型。 相似文献
12.
应用GM(1,1)模型研究军用电子元器件的长期贮存寿命 总被引:4,自引:1,他引:3
现代武器装备“长期贮存,一次使用”的特性,要求装备的各个部件和元器件都具有良好的环境适应性与长期贮存寿命。根据灰色系统理论,以某电阻器为例,应用GM(1,1)模型及其改进模型预测了其长期贮存寿命,所建立的模型具有较好的精度,有一定的参考价值。实践证明:灰色预测方法简单、实用,具有一定的工程应用价值。 相似文献
13.
针对目前电动车续驶里程短、电池易老化、爬坡能力差、能量回收效率低的缺陷,研究以比功率高、循环寿命长的超级电容作为辅助电源,实现了一种新型超级电容-蓄电池复合电源系统.从超级电容-蓄电池系统的结构出发,对电动车的行驶工况进行了具体分析,构建了超级电容充电模型和超级电容-蓄电池复合电源系统模型.仿真和实际试验结果表明,该复合电源系统能有效回收制动能量,从而使蓄电池的低能量密度和低功率密度等缺陷得到弥补,进而提高电动车动力性能和电能的利用率,使电动车的续驶里程增长,能有效地降低蓄电池电压和电流幅值波动,延长蓄电池的使用寿命. 相似文献
14.
Energy storage system, usually a battery, become essential part for all electric drive vehicles such as hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV) and electric vehicle (EV) in the coming decades. These energy storage systems include Li-ion batteries, Ni-MH batteries, lead-acid batteries and ultra-capacitors. An accurate Battery Management System (BMS) is highly demanded integrated system in all electric derive vehicles to ensure the optimum use of an energy storage system. The battery's state monitoring & evaluation, charge control and cell balancing are the important features of any BMS. However, due to unavailability of inaccurate battery's state-of-charge (SoC)/state-of-health (SoH) estimators and uncertainty of battery's performance, new approaches of BMS design are under development to control batteries optimally and hence, the vehicle performance. In addition, most of the existing BMSs either do not provide SoH at all or provide it as a function of capacity degradation over the battery usage. This research paper presents the field-programmable gate array (FPGA) - based Advanced BMS design using MATLAB-to-FPGA design flow. The Advanced BMS design provides the combined estimation of both SoC and SoH of a rechargeable battery. This research paper also summarizes the Neuro-Fuzzy & statistical models implemented in Advanced BMS for accurate estimation of battery's SoC & SoH respectively. Further, this research paper presents the selection of suitable FPGA and its hardware realization implementing Advanced BMS. Finally, the experimental results are confirmed by simulation and synthesis of its register transfer level (RTL) design. FPGA-based Advanced BMS would provide the best chip solution for a generalized BMS with benefits of low Non-recurring engineering (NRE) cost, low power consumption, high speed of operation, large reconfigurable logic and large data storage capacity. 相似文献
15.
Power-Electronics-Based Solutions for Plug-in Hybrid Electric Vehicle Energy Storage and Management Systems 总被引:2,自引:0,他引:2
16.
1introductionInsystemscience,scholarsoftenusedarkorlightcolortodescribetheself-containedextentofinformation.Ingeneral,"white"meansthattheinformationiscomplete,and"back"meansthattheinformationisunknownatallwhile"grey"meansthattheinformationisincompleteorunknownforsure.Soanumber,whoseinformationisincomplete,iscalledgreynumberAnelement,whoseintbrmationisincomplete,iscalledgreyelement;theincompletemutualrelationbetweensystemsorfactorsiscalledgreyrelation;and,iftheinformationisincompleteorunknownfo… 相似文献
17.
设计了一种用于电动车的混合电源系统。该系统以蓄电池为主电源,采用具有双电层结构的超级电容器为辅助能源。利用单片机控制电动车在不同状态选择不同电源进行供电。以200 kg的人与车沿着仰角为30°,落差为6 m的坡度行驶进行实验,可增加130 m的行驶距离。这表明该混合电源有效地增加了电动车的行驶里程,同时可延长蓄电池的使用寿命,具有很大的现实推广意义。 相似文献
18.
分析和比较了四种非隔离型双向DC/DC变换器的拓扑结构。针对目前广泛使用的混合动力电动汽车存在的环保问题和电池性能问题设计了一种双向DC/DC变换器一两相交错双向DC/DC变换器,论述了其工作原理,并通过一台3000W的样机验证了理论的正确性。 相似文献
19.
采用灰色理论、BP神经网络、布朗三次指数平滑算法来对雷达风场预测进行研究。利用香港国际机场激光雷达数据对风场PPI扫描风速进行预测,得到了预测时刻机场区域整个风场的概况,让飞行员能提前了解机场区域内未来一段时间的风场环境;使用下滑道扫描数据对飞机在下滑道附近的迎头风进行预测,从而更精确地预测飞机在起飞和降落过程中将会遇到的风场波动,使飞行员能够在风切变探测系统告警之前,增加飞行员进行反应和相关准备的时间。对实验结果的统计分析表明:布朗三次指数平滑预测在延长预测时间时,预测精度随时间的增加而下降的趋势较明显;灰色预测和BP网络预测在风场变化很大的情况和延长预测时间时,仍能在一定程度上保证预测精度;灰色预测较BP网络预测效果稍好。 相似文献
20.
ADVISOR-based model of a battery and an ultra-capacitor energy source for hybrid electric vehicles 总被引:4,自引:0,他引:4
An energy source is the heart of a hybrid electric vehicle. If it is capable of supplying enough power at all times, then it is an adequate source. Major problems presently facing the industry include the size, cost, and efficiency of the energy source. The primary energy source presently used in automotive systems is a battery. In order to reduce the cost of the battery, the current needs to be decreased and stabilized so it is not very erratic. The purpose of this paper is to introduce and justify the use of a new model for an energy source: a battery in parallel with an ultra-capacitor. The ultra-capacitor can supply a large burst of current, but cannot store much energy. Conversely, the battery can store mass amounts of energy; however, without expensive and inefficient units, a battery cannot provide the current that the ultra-capacitor can. By combining the two energy sources in parallel, the storage and peak current characteristics desired can be achieved. The standards of the vehicle are not degraded, allowing this to be a promising technique to incorporate into hybrid electric vehicles to reduce their cost and increase the efficiency of their energy-source system. 相似文献