功率混合型燃料电池汽车动力系统的恒压式能量分配算法

分析了功率混合型燃料电池汽车动力系统的特征,给出了功率混合型动力系统能量分配算法的实用设计原则,阐述了该型动力系统适用的恒压能量分配方式,并依据提出的设计原则进行了能量分配算法设计。在燃料电池城市客车“清能3号”的应用中,又提出一种分模式控制解决方案。实验证明,所设计的算法能综合考虑动力系统的部件安全性、动力性和经济性,具有一定的应用价值。     

Magic Formula轮胎模型参数辨识的一种混合优化方法

Magic Formula(MF)轮胎模型能够准确描述轮胎的侧偏特性,广泛应用于车辆动力学的研究。由于MF轮胎模型参数多,且高度非线性,从大量的试验数据中准确辨识这些参数相当困难。提出一种基于遗传算法和数值优化算法的混合优化方法,采用由粗到精的辨识过程,先利用遗传算法得出近似最优解,再利用数值优化算法辨识出精确的参数。利用辨识出的参数计算轮胎的侧偏特性,计算结果与试验数据吻合良好,表明该方法是辨识MF轮胎模型参数的有效手段。     

遗传算法在双横臂悬架优化中的应用

针对ADAMS软件提供的优化算法的用户接口,成功地将遗传算法(Genetic Algorithm)添加到ADAMS中;并且以降低轮胎磨损为目标,利用所添加的遗传算法对双横臂悬架进行优化设计,获得良好的优化效果。     

Instantaneous frequency estimation of multi-component Chirp signals in noisy environments

A classical time-varying signal,the multi-component Chirp signal has been widely used and the ability to estimate its instantaneous frequency(IF) is very useful. But in noisy environments,it is hard to estimate the IF of a multi-component Chirp signal accurately. Wigner distribution maxima(WDM) are usually utilized for this estimation. But in practice,estimation bias increases when some points deviate from the true IF in high noise environments. This paper presents a new method of multi-component Chirp signal IF estimation named Wigner Viterbi fit(WVF) ,based on Wigner-Ville distribution(WVD) and the Viterbi algorithm. First,we transform the WVD of the Chirp signal into digital image,and apply the Viterbi algorithm to separate the components and estimate their IF. At last,we establish a linear model to fit the estimation results. Theoretical analysis and simulation results prove that this new method has high precision and better performance than WDM in high noise environments,and better suppression of interference and the edge effect. Compared with WDM,WVF can reduce the mean square error(MSE) by 50% when the signal to noise ration(SNR) is in the range of -15dB to -11dB. WVF is an effective and promising IF estimation method.     

Basic design of a series propeller with vibration consideration by genetic algorithm

Genetic algorithms (GAs) can powerfully search for parameters in a large multidimensional design space. Thus, the principle can be applied to preliminary series propeller design problems with multiple considerations. In the present study, B-series propeller design was conducted using a GA for both hydrodynamic efficiency and vibration consideration. The objective function was set by users who could freely weight the relative importance of efficiency and vibration. GAs were successfully shown to be able to obtain an optimal set of parameters leading to efficient performance and low vibration.     

客运专线列车运行图编制模型及计算方法的研究

列车运行图是铁路行车组织工作的基础,其编制问题属于超大规模的多目标优化问题,求解难度较大。既有线列车运行图较为成熟的编制理论和计算方法对客运专线列车运行图的编制具有重要的借鉴作用。在既定客运专线运输组织模式的基础上,提出基于客运专线A类本线、B类跨线和本线城际列车运行图铺划的分层叠加数学模型,研究客运专线不同种类列车的布点模型和求解方法,设计了基于改进型遗传算法的客运专线列车运行图优化策略和算法。算例表明,该算法能有效地求解客运专线列车运行图编制方案,并达到快速准确的良好效果,为编图人员提供优选方案。     

高速单体船快速性和操纵性综合优化混沌算法

以高速单体船为研究对象,通过了综合论证及分析,建立了以快速性和操纵性为目标函数的综合优化数学模型。以MATLAB6.5为工作平台,应用变尺度混沌优化算法,编制了优化程序,并对高速单体船快速性和操纵性的仿真模型进行在线优化。优化结果表明:变尺度混沌算法对高速单体船快速性和操纵性综合优化是有效且可行的。     

基于MATLAB的船舶快速性和结构特性综合优化初步研究

以MATLAB 6.5为工作平台,使用仿真软件Simulink对高速单体船快速性以及结构特性的联合系统建立了数学模型。通过程序计算比较得出各设计变量的较优组合。在此基础上,从混沌变量、权系数不同、目标函数形式以及敏感变量等多个方面对结果的影响做出了分析。计算结果表明:变尺度混沌算法是有效且可行的。     

New strategies for collision resolution of multi-access channel

ABSTRACT： The truncated binary exponential back-off algorithm is one of the most effective methods applied in collision resolution process of random multi-access channel. In this study, two new strategies are presented to improve the capability of the truncated binary exponential back-off algorithm. In the new strategies, the sizes of the initial window size or the operating window sizes are adjusted dynamically, which always bring a significant improvement for the self-adaptability of the original A series of experiments are simulated and the results verify that the new strategies can make the implementation more stable and effective than the original algorithm.     

基于遗传算法的机车二系支承载荷调整优化方法

为了改善机车轮轴重量分配的均匀性,从分析机车二系支承结构出发,建立二系载荷分布弹簧高度调整模型,提出应用遗传算法实现机车二系支承点加垫高度值的快速优化计算。针对机车二系支承载荷分布多维参数优化问题的特点,给出基于实数编码的改进遗传算法模型。对国产SS9,SS3b型机车实际应用,可使二系支承载荷分布最大误差进一步减小8%～15%,平均计算过程时间减少约20%。结果表明这种方法克服了基于误差梯度信息迭代搜索求解支承点加垫最佳值算法的不足,在获得一致的全局优化(近似)解,以及在减小运算时间、提高调簧算法的可靠性和实时性等方面具有明显的效果。