GIS中基于栅格转换的缓冲区生成算法

缓冲区生成是GIS中非常重要的一种分析方法,现有的算法数据量大、运算效率低.在\"DEComGIS的研究与开发\"课题中我们运用栅格转换来实现缓冲区生成,实践证明该算法是有效的.     

基于遗传算法的汽车拉式离合器膜片弹簧结构参数优化设计

膜片弹簧是膜片弹簧离合器的关键零件。本文通过分析离合器的载荷一变形特性和多种约束条件,在参考成熟离合器结构参数的基础上,提出了一种离合器膜片弹簧的优化设计模型：在摩擦片磨损极限范围内,把弹簧压紧力变化的平均值最小作为优化目标。并采用遗传算法对某轻型货车离合器膜片弹簧进行优化设计计算。结果表明,应用此模型优化后的膜片弹簧各决策变量的值明显优于利用传统经验公式设计所得的结果。无论是在后备系数的稳定性、膜片的最大当量应力方面,还是在分离力的大小方面,均明显优于原设计。     

Designing H ∞/GH 2 static-output feedback controller for vehicle suspensions using linear matrix inequalities and genetic algorithms

This paper presents an approach to design the H _∞/GH ₂ static-output feedback controller for vehicle suspensions by using linear matrix inequalities (LMIs) and genetic algorithms (GAs). Three main performance requirements for an advanced vehicle suspension are considered in this paper. Among these requirements, the ride-comfort performance is optimized by minimizing the H _∞ norm of the transfer function from the road disturbance to the sprung mass acceleration, while the road-holding performance and the suspension deflection limitation are guaranteed by constraining the generalized H ₂ (GH ₂) norms of the transfer functions from the road disturbance to the dynamic tyre load and the suspension deflection to be less than their hard limits, respectively. At the same time, the controller saturation problem is considered by constraining its peak response output to be less than a given limit using the GH ₂ norm as well. A four-degree-of-freedom half-car model with active suspension system is applied in this paper. Several kinds of H _∞/GH ₂ static-output feedback controllers, which use the available sprung mass velocities or the suspension deflections as feedback signals, are obtained by using the GAs to search for the possible control gain matrices and then resolving the LMIs together with the minimization optimization problem. These designed H _∞/GH ₂ static-output feedback controllers are validated by numerical simulations on both the bump and the random road responses which show that the designed H _∞/GH ₂ static-output feedback controllers can achieve similar or even better active suspension performances compared with the state-feedback control case in spite of their simplicities.     

基于遗传算法的盾构隧道管片接头刚度反演研究北大核心CSCD

梁-弹簧模型在管片衬砌结构计算中应用较广泛,目前接头刚度取值方法主要有模型试验法及经验取值法,模型试验法耗时长、成本高昂,而依据经验取值难免存在一定主观性。鉴于此,利用C++编程语言,基于遗传算法开发了盾构隧道管片结构位移反分析程序,首先通过弹性模量值反演算例,得出反演值与理论值误差为1.4%,验证了算法和程序的可行性。利用程序将反演接头刚度值与实际设计案例管片接头刚度值进行对比,反演计算结果表明:正弯矩下管片环向接头转动刚度值反演误差为2.6%,负弯矩下管片环向接头转动刚度值反演误差为4.3%。     

基于C-均值聚类算法的列车故障诊断系统

介绍了2动1拖内燃电传动动车组网络拓扑结构、列车故障诊断系统,故障分类等级及应用C-均值聚类算法准确识别列车故障评估方法,阐述列车诊断系统收集并处理故障信息后,根据聚类核心及数据样本形成平方和聚类准则,对数据样本进行决策分析并输出诊断结果。人机接口设备可存储并及时显示列车故障。列车故障诊断系统增强了动车组运行的可靠性,减少维护人员的工作量,有助于列车长期稳定运行。     

逆变器的电容老化故障诊断方法研究

以CRH3C型动车组逆变器中的绝缘栅双极型晶体管（IGBT,Insulated Gate Bipolar Transistor）双管开路故障为研究对象,提出了一种基于非洲秃鹫算法（AVOA,African Vultures Optimization Algorithm）和优化的反向传播（BP,Back Propagation）神经网络的逆变器故障诊断方法。在Simulink中搭建列车逆变器的控制模型,取得故障电流;采用经验模态分解（EMD, Empirical Mode Decomposition）对电流信号进行去噪和故障特征提取,再利用AVOA对BP神经网络进行优化,实现了对列车逆变器IGBT双管开路故障的诊断。与传统方法进行对比可知,该方法具有更高的精准度,在测试集中其精准度达到100%。

     

基于自适应遗传算法的某款纯电动汽车智能发电策略分析

纯电动汽车动力电池容量有限,这是困扰其大力推广关键因素之一,若一味提升电池容量将大大提高整车成本。因此,在纯电动汽车动力电池容量不变和保证车辆行驶舒适安全前提下,提出续航里程提升策略至关重要。文章提出通过搭载风力发电机和制动回馈电机发电策略有助于续航,分析风力发电与制动能量回馈影响因素并研究纯电动汽车风力发电与制动能量回馈系统控制模型结构后,充分考虑汽车所受阻力,电能转换效率提升方法,建立智能发电能量模型。最后采用遗传算法将空气湿度,制动强度,电池荷电状态,行车速度等因素作为决策变量,并在 Matlab 软件中仿真,得出了随着风力发电机与制动回馈电机平稳运转后,风力发电与制动能量回馈之和处于最佳发电值,验证了发电策略可提升动力电池的充电量,增大纯电动汽车的续航里程。     

基于遗传算法的操舵仪控制参数在线优化

采用遗传算法对航向保持自动操作仪控制参数进行在线优化,计算机仿真表明,遗传算法可以方便地得到全局最优解,故控制器可以快速稳定地跟踪预定航向,且系统具有较好的鲁棒性。