基于模型预测控制的智能车轨迹跟踪控制研究

为了完成智能车的轨迹跟踪,提出一种基于模型预测控制的轨迹跟踪方法,利用将运动学模型这个非线性系统线性化的方案,来获得必须的线性时变系统,采取模型预测控制的三要素来设计控制器。并且基于MPC在控制过程中能增加多种约束的优点,建立基于车辆运动学模型的约束做轨迹跟踪仿真实验,最后,基于山东理工大学智能车平台上GPS提供的定位信息,在校园中采集路线并对前提规划好的的轨迹进行实车验证。实验结果表明:基于MPC算法所设计的控制器能快速且稳定地跟踪期望轨迹。     

马尔柯夫灰色残差模型在剐构桥控制中的应用

文章结合罗天乐特大桥的马尔柯夫灰色残差模型预测实例,介绍马尔柯夫灰色残差模型在线性控制中的原理、计算及应用过程,并根据实际监控经验提出了建议。罗天乐特大桥的具体监控应用实践表明,马尔柯夫灰色残差模型预测精度高,能较好地应用于大跨连续刚构桥的施工线形控制。     

基于三点模型的柴油机热工参数预测

准确预测热工参数劣化趋势是对柴油机实施预测维修的前提。已有预测技术均视不同时段信息所具有的建模价值相等,忽略了近期信息比远期信息更能反映设备当前运行态势这一客观事实,导致预测模型难以准确描述柴油机热工参数的真实变化规律。针对该问题,提出一种基于三点模型的柴油机热工参数预测方法,并采用新陈代谢法同步更新建模数据,以提高建模数据的利用效率及预测精度。与灰色系统GM(1,1)模型预测精度的对比结果表明,三点模型能够有效处理不同时段信息在反映设备运行态势能力上的差异,得到更为准确的预测结果。     

基于HMM-SVR的船舶动力设备故障模式识别与状态预测研究

船舶动力设备因故障监测信号样本少、变化缓慢且数据特征呈非线性,使得设备故障模式的准确识别和状态预测比较难。鉴于此,文章研究了基于隐马尔科夫模型的故障模式识别方法,利用该模型将微弱变化的信号特征转换为变化较大的对数似然概率对故障模式实现有效识别。在此基础上进一步提出基于HMM-SVR的设备状态预测模型,将遗传算法用于支持向量回归模型参数寻优,并结合隐马尔科夫模型,实现对设备状态的预测。对船用柴油机进行仿真,结果表明上述模型具有较高的识别率,能准确预测船舶动力设备的当前状态。     

Soil Body Deformation Caused by Construction of a Double-Line Shield Tunnel with Multiple Factors北大核心CSCD

Considering the influence of many factors (soil loss, frontal additional thrust, the friction force of the shield shell and the additional grouting force), a method for improving the uniform soil body movement model is pro-posed, and a mechanical calculation model is established to study the calculation method for soil body deformation caused by double-line parallel shield driving. Based on the Mindlin solutions of elastic mechanics, the theoretical solutions for soil body deformations caused by the last three factors are calculated; considering the uniform soil body movement model, the theoretical solutions for soil body deformations caused by soil loss are calculated, then the to-tal theoretical solutions for soil body deformations under multiple factors are obtained by means of superposition. The vertical surface settlement, vertical horizontal displacement, and vertical displacements of the soil body at different depths of Hangzhou Metro Line 1 are calculated to analyze the variation laws. Meanwhile the influential factors for horizontal displacement variation are studied. The research shows that with a change of depth, the settlement of the soil body changes within the scope of 10 to 13 m in the horizontal direction near where the maximum settlement occurs;the direction of the horizontal displacement of the soil body changes with a change of the positional relationship be-tween the calculation points and the tunnel; and with an increase of interval J for the two tunnels, the horizontal dis-placement of the soil body of a deep double-line tunnel decreases while the displacement near the surface changes slightly. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Situation analysis forecasting: the case of European maritime clusters

Within the literature concerned with aspects of competitiveness, innovation and strategic management of industrial clusters, the body regarding forecasting of strategic management is still nascent. This work aspires to render a contribution within the domain of strategic management forecasting, through the indicative case of European maritime clusters. For this end, a two-tier model is formulated. A quantitative strengths, weaknesses, opportunities, and threats (SWOT) methodology that derives from the fusion of a quondam situation analysis and crosstabs’ theory is generated. This leads to the utilization of the crosstab’s conditional probabilities as transition probabilities; the latter are called to compile the transition matrix of a Markov chain. Through this methodology, and the successive Markov chain’s transition matrices, strategic forecasts are extracted for a devised European maritime cluster case. This work relinquishes a novel application with respect to strategic management forecasting, that provides a dichotomy of practical interpretations and scenarios for quantitative situation analysis. Thus, it may enable effective real-time decision-making for strategic management and/or policy drafting. The situation analysis forecasting model may find applicability in a plethora of practical and theoretical cases, wherein forecasting may be desirable. It may as well pertain to an intrinsic methodology for situation analysis forecasting of maritime clusters.     

美国联邦公路局路阻函数探讨

路阻函数在交通分配过程中左右着路径的选择,目前广泛采用的路阻函数是美国公路局提出的BPR函数,但在交通分配的实践过程中使用美国公路局推荐BPR参数得到的结果并不理想。论文对国内外关于BPR函数的修正模型研究进行了介绍;分析了现存BPR模型的优点与缺陷;提出了BPR函数适用情况的思考。     

共享单车现金奖励调度策略的用户接受意愿研究

为探讨共享单车用户在不同影响因素下对现金奖励调度策略的接受程度,设定了针对共享单车用户的调查问卷,并在济南市进行了调查,得到519份有效问卷。基于扩展的计划行为理论（Extended Theory of Planned Behavior, ETPB）模型和相关结构方程模型（Structural Equation Model, SEM）,设定了社会规范、支付能力、体力、感知服务、感知绿色价值5个构念以及5个相关假定,以测度不同奖励调度情境下共享单车用户对奖励策略的接受程度。结果显示,支付能力和体力对用户接受调度的影响程度最大,其次是社会规范和感知服务,感知绿色价值的影响程度最小。在此基础之上,提出了增大站点密度、实行现金奖励及提高车辆质量等建议,以降低运营成本、提升用户满意度与车辆使用率。     

大连新建地铁对公交出行选择的影响

为了分析城市新建地铁项目对居民公共交通出行的影响,改善公交服务水平,提高公共交 通的分担率,针对大连市新建地铁线路展开研究。以大连市地铁1 号线沿线站点作为研究区域, 采用SP （Stated Preference） 调查方法,收集了300 名地铁沿线居民对常规公交以及新建地铁两种 出行方式的选择数据。通过建立二项Logit 模型,分析出行成本、换乘时间等选择方案特性变 量,出行特性变量以及出行者特性变量对于居民出行方式选择行为的影响,并计算弹性值及模型 精度。结果表明,通过调整出行成本及换乘时间可有效提高地铁分担率。由此提出相关政策建 议：对于出行成本,可从出行者年龄及出行次数两方面制定不同的优惠政策;对于换乘时间,可 从提高可达性、完善购票系统以及调整发班频率三方面进行改善。     

m阶非齐次马氏信源的一类Shannon-Mcmillan定理

采用构造相容分布与非负上鞅的方法研究了m阶马氏信源相对熵密度的强极限定理,由此得出若干马氏信源、无记忆信源的随机Shannon-Mcmillan定理.并将已有的马氏信源的结果加以推广.