基于星敏感器的载体角速度测定方法研究

提出了一种新的测定航天器角速度矢量的方法。该方法只需得到来自星敏感器的载体矢量测量信息,就可确定载体角速度。提出了基于各种不同差分法的运算规则,表示出了每种近似法的估计误差协方差。仿真结果表明,结合简单的滤波,该方法能够提供非常精确的角速度估计值,而且计算量远比卡尔曼滤波小得多。     

场桥燃油计量系统技术改造

为了提高油量计量的准确性,研发了一套新的油位计量系统。介绍了传统的油位计量模式,和改进后的油位计量装置,并对两者效果作了比较。改造后的油位计量系统用超声波检测并可进行油量实时采取。达到了准确计量油量的效果。     

关于潍坊市城乡公交一体化的思考

城乡公交一体化改造是指城市客运主管部门根据城市建设和发展的需要,通过整合城市公交、区间客运、出租客运、城市与农村之间以及城市周边农村等各种城乡公共交通资源,形成连接城乡、布局合理、经营规范、安全便捷、服务优质、方便出行的公共交通运营网络.下面就潍坊城乡公交一体化改造的必要性,改造中的突出矛盾,如何化解矛盾,改造后公共资源共享等方面进行阐述.     

CoFe2O4的磁性和交换偏置场研究

用化学共沉淀法制备出颗粒细小的CoFe2O4纳米微粉,利用x射线衍射确定了粉体的组成,利用扫描电子显微镜观察了颗粒的形貌,利用振动样品磁强计测量了室温下粉体的磁性能。结果显示,常温下,存在交换偏置场。     

两种卸船机的特点及布置方案对比

两种常用散货卸船机的性能特点很不相同,设备选型和布置必须保证合理性,以免造成港口码头卸船效率降低和资源浪费.     

An adaptive information fusion model to predict the short-term link travel time distribution in dynamic traffic networks

As intelligent transportation systems (ITS) approach the realm of widespread deployment, there is an increasing need to robustly capture the variability of link travel time in real-time to generate reliable predictions of real-time traffic conditions. This study proposes an adaptive information fusion model to predict the short-term link travel time distribution by iteratively combining past information on link travel time on the current day with the real-time link travel time information available at discrete time points. The past link travel time information is represented as a discrete distribution. The real-time link travel time is represented as a range, and is characterized using information quality in terms of information accuracy and time delay. A nonlinear programming formulation is used to specify the adaptive information fusion model to update the short-term link travel time distribution by focusing on information quality. The model adapts good information by weighing it higher while shielding the effects of bad information by reducing its weight. Numerical experiments suggest that the proposed model adequately represents the short-term link travel time distribution in terms of accuracy and robustness, while ensuring consistency with ambient traffic flow conditions. Further, they illustrate that the mean of a representative short-term travel time distribution is not necessarily a good tracking indicator of the actual (ground truth) time-dependent travel time on that link. Parametric sensitivity analysis illustrates that information accuracy significantly influences the model, and dominates the effects of time delay and the consistency constraint parameter. The proposed information fusion model bridges key methodological gaps in the ITS deployment context related to information fusion and the need for short-term travel time distributions.     

Suspension system state estimation using adaptive Kalman filtering based on road classification

This paper provides a new method to solve the problem of suspension system state estimation using a Kalman Filter (KF) under various road conditions. Due to the fact that practical road conditions are complex and uncertain, the influence of the system process noise variance and measurement noise covariance on the estimation accuracy of the KF is first analysed. To accurately estimate the road condition, a new road classification method through the vertical acceleration of sprung mass is proposed, and different road process variances are obtained to tune the system’s variance for the application of the KF. Then, road classification and KF are combined to form an Adaptive Kalman Filter (AKF) that takes into account the relationship of different road process noise variances and measurement noise covariances under various road conditions. Simulation results show that the proposed AKF algorithm can obtain a high accuracy of state estimation for a suspension system under varying International Standards Organisation road excitation levels.     

中国低碳交通指标体系初探

在碳排放的形势日益严峻的情况下，减少道路交通的排放是控制温室气体排放的重要手段。通过对国外研究机构和各国政府的低碳交通政策与指标发展的综述，对低碳交通指标体系进行初步研究，为建立适合我国国情的低碳交通指标体系提供参考。     

王双树特大桥岩溶土洞塌陷危险性评价研究

根据王双树特大桥的水文地质、工程地质条件,结合该地区岩溶发育程度和地下水状况,分析了岩溶、土洞形成过程和发展模式,对该桥岩溶产生土洞塌陷的危险性进行了评价,并提出相应的工程措施建议。     

CFG桩施工参数自动记录仪及其应用

通过分析CFG桩施工质量控制存在的问题,详细介绍了CFG桩施工参数自动记录仪的原理、性能、使用方法以及在京沪高速铁路李窑路基CFG桩试验段的应用效果.