基于UKF算法的车辆质心侧偏角估计

将无味卡尔曼滤波(UKF)算法运用到车辆质心侧偏角的估计之中,基于纵滑—侧偏联合工况下的统一指数(Uni-tire)轮胎模型建立非线性车辆动力学模型,采用最小偏度单形采样的UKF算法估计车辆的几个关键状态参量,并由此得到质心侧偏角估计。最后采用奇瑞A3两厢型汽车的车辆参数,使用车辆动力学实时仿真软件DYNAware/veDYNA对观测器进行了实时验证。仿真结果表明,UKF非线性估计方法精度高,估计结果能够满足实际应用要求。     

铁路信号安全关键软件的组合测试序列集约简

针对现有铁路信号系统安全关键软件t-路组合测试序列生成方法在处理大规模输入时产生冗余测试序列,导致测试执行成本较高的问题,提出了一种基于贪婪-粒子群混合优化算法的t-路组合测试序列集约简方法,用于降低序列集的执行成本. 首先,以执行成本最低为约简目标,建立针对t-路组合测试序列集约简的优化模型;然后,在保证测试序列集逻辑覆盖特性的基础上,采用贪婪-粒子群混合优化算法求解模型,计算约简后的测试序列集;最后,以ZPW-2000轨道电路接收器软件作为研究对象,以其生成的2-路组合测试序列集为例开展约简验证. 结果表明,所提方法在保证2-路组合覆盖和逻辑覆盖的前提下,对单个序列集的执行成本约简幅度最高达到98.33%,对序列集总的执行成本约简幅度达到36.10%,验证了所提方法的可行性和有效性.      

Control method of three-level neutral-point-clamped inverter based on voltage vector diagram partition

A new modulation approach was presented for the control of neutral-point (NP) voltage variation in the three-level NP-clamped voltage source inverter, and the average NP current model was established based on vector diagram partition. Thus, theory base was built for balancing control of NP potential. Theoretical analysis and experimental results indicate that the proposed method for NP balancing control vector synthesizing concept based can make the average NP current zero, and do not influence NP potential within every sample period. The effectiveness of proposed research approach was verified by simulative and experimental results.     

斜拉桥索塔锚固区环形预应力束孔道摩阻试验研究

通过某公路立交桥索塔锚固区节段足尺模型试验,实测索塔锚固区内环形预应力钢束的摩阻系数、应力损失率和伸长量等数据,与设计数据进行校核、修正,并确定实际的环形预应力束张拉的摩阻系数以及初始张拉控制应力值．使环形预应力束张拉伸长值控制在合理范围。     

Signal coordination model for local arterial with heavy bus flows

Conventional Transit Signal Priority (TSP) controls often reach the limitation for arterials accommodating heavy bus flows since the priority function can significantly increase delay at minor streets. Under such conditions, a proper signal progression plan that accounts for the benefits of buses may offer the potential to improve the reliability of bus operations and increase the bus ridership. This study proposes a bus-based progression model to reduce the delay of buses on local arterials. Given the cycle length and green splits at each intersection, the bus-based progression model, grounded on the same notion as conventional signal progression methods, considers the operational characteristics of transit vehicles, such as the impact of bus dwell time and the capacity constraints at bus stops. Also, to deal with the stochastic nature of dwell time, this study introduces additional constraints to maximize the percentage of buses which can stay within the green band after leaving bus stops. Taking an arterial with five intersections and three two-way bus stops as an example, this study applies VISSIM as an unbiased tool for model evaluation. The simulation results demonstrate that the proposed model can significantly reduce bus passenger delays and the average person delays for the entire arterial, compared with the conventional progression models.     

船舶自动舵灰色预测模型及其DSP实现技术研究

本文应用灰色系统理论对船舶自动航行的核心部件--自动舵的控制系统进行研究,针对传统控制模型的不足之处以及自动航行的最优化要求,提出了灰色预测模型并应用DSP进行硬件实现.利用灰色理论在处理不规则和非线性问题上的优势以及DSP的高速数据处理能力,更好地克服传统PID控制的缺点,同时满足了自动舵控制的大信息量和实时性需要.     

主宰集装箱港口发展的国际港口

集装箱港口(码头)是投资回报比较丰厚的行业。在经济全球化和资本全球化，以及发展中国家港口经营私有化的推动下，集装箱港口(码头)的业务经营向为数不多的国际港口集团集中的趋势日益明显。据伦敦德鲁里航运咨询公司的分析报告，世界前十大码头经营人控制着全球集装箱吞吐量的45．3％(见表1)，而世界前二十大码头经营人仅控制着全球集装箱吞吐量的56．7％。     

深溪沟排水洞工程围岩分类研究

国电大渡河流域深溪沟水电站的附属工程深溪沟排水洞工程围岩环境复杂,通过RMR、Q、水电规范等手段进行排水洞复杂围岩进行了施工期间围岩分类技术,为隧洞工程尤其是复杂地质条件下围岩分类提供简单易行的方法和信息化施工依据。     

现浇大体积混凝土用永久性钢筋混凝土护筒模板防裂措施的研究

离岸外海工程不断涌现，海上大体积混凝土结构的施工是工程建设者所面临的一个重大技术问题。预制永久性钢筋混凝土护筒模板的施工方案是加快海上大体积混凝土施工速度的优选方案之一。现浇大体积混凝土所释放的水化热将在护筒模板内外形成较大温差，产生较大温度应力，有导致护筒模板产生开裂的趋势。通过理论分析及试验研究提出现浇大体积混凝土用护筒模板的防裂措施，对离岸工程大体积混凝土施工技术具有指导意义。