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全站仪观测桥梁挠度的探讨 总被引:1,自引:0,他引:1
采用全站仪和精密水准仪同条件观测桥梁挠度,选定了相应的观测方法,通过精密水准仪观测数据检核全站仪观测成果,并应用误差传播定律进行精度分析,理论和实践均证明全站仪可满足挠度观测精度要求。 相似文献
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以港珠澳大桥主体工程青州航道桥为实例,分别使用连通管桥梁挠度测量系统及电子水准仪对荷载试验中关键的挠度测点进行了检测,并对两种检测结果进行了比对.结果表明,连通管法及水准仪法结果高度吻合,误差均在1%以内.该结果对连通管法在桥梁荷载试验挠度检测的使用有着重要的借鉴意义. 相似文献
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中小跨径桥梁刚度大、挠度小,因此对挠度测试精度要求高。对常见的位移计、水准仪和全站仪3种挠度测试仪器和方法进行了比较。分别采用理论和实测的方法定量地研究了这些测量方法的误差。研究表明:实测精度一般要比理论精度低5倍。从测试精度来说,位移计较高、水准仪次之、全站仪较低;从使用方便来说,则顺序正好相反,全站仪最方便,而位移计对环境要求较严格。因此,对于中小桥梁挠度测试,在条件允许搭设支架时应优先使用位移计,在无搭设支架条件时可以考虑使用水准仪,无法使用位移计和水准仪时再考虑采用全站仪,并应配合使用棱镜。 相似文献
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根据桥梁施工中,需要放样桥梁墩台、桥面的设计高程,传统的水准仪和三角高程放样方法有一定的局限性。采用全站仪中间法三角高程测量,可以仿照常规水准仪的测量方式,不需对中和量取仪器高,通过误差传播定律进行精度估算和分析,此法可以达到国家三等水准要求,完全满足桥梁高程施工放样的要求。 相似文献
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针对目前桥梁变形监测技术存在精度低、无法实现实时监测和易受环境影响等缺点,提出利用基于CCD静力水准仪传感器的自动化监测系统对桥梁变形进行监测。基于对昆明市虹桥路匝道桥施工对既有桥梁结构影响的研究,采用静力水准仪系统对既有桥梁变形进行监测,对该桥不同位置设21个测点,经过长达20 d的监测,变形监测频率为4次/d,共得到1 680组数据。通过选取典型测点的监测数据进行分析,并与精密水准测量进行数据对比,可得静力水准仪系统具有测量精度高、自动化程度高、稳定性好等特点,在桥梁变形监测领域具有较高的推广价值。 相似文献
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蒙华铁路洞庭湖特大桥主桥为(98+140+406+406+140+98)m三塔双索面钢梁斜拉桥。主梁为钢箱钢桁结合梁,钢箱梁处于结合梁的下部,主桁下弦和钢箱顶板焊接连接。边跨主梁采用顶推施工,中跨主梁采用悬拼施工,最后在跨中合龙,主梁架设采用"先箱梁后桁梁"的施工技术,为确保架设精度,采用钢梁架设专用加密控制网并精密联测设置基准点的方法;对加工误差累积管理以控制钢梁制造误差;以固定仪器、人员和点位的测量方式控制边跨顶推落梁精度;采用差分极坐标和闭合水准法精密控制钢箱梁拼装误差;采用差分三维坐标法控制钢桁梁转角和预留调整口轴向偏差。 相似文献
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详细地介绍了平面度检测方法和误差评定,选用水准仪及特制标尺,用水平面作为车架平面度进行检测的模拟基准。分析了自制专用标尺的检测方法及原理。 相似文献
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B. M. Duan Q. N. Wang J. N. Wang X. N. Li T. Ba 《International Journal of Automotive Technology》2017,18(2):335-344
This paper presents a calibration method of a rule-based energy management strategy designed for a plug-in hybrid electric vehicle, which aims to find the optimal set of control parameters to compromise within the conflicting calibration requirements (e.g. emissions and economy). A comprehensive evaluating indicator covering emissions and economy performance is constructed by the method of radar chart. Moreover, a radial basis functions (RBFs) neural network model is proposed to establish a precise model within the control parameters and the comprehensive evaluation indicator. The best set of control parameters under offline calibration is gained by the multi-island genetic algorithm. Finally, the offline calibration results are compared with the experimental results using a chassis dynamometer. The comparison results validate the effectiveness of the proposed offline calibrating approach, which is based on the radar chart method and the RBF neural network model on vehicle performance improvement and calibrating efficiency. 相似文献
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欲保证基于摄影测量的汽车行驶跑偏在线自动测试系统的测试精度,需对测试用CCD相机进行精确标定.CCD相机标定常用的算法有空间后方交会法和直接线性变换(DLT)法等2种.通过对2种相机标定方法基本原理的分析,结合汽车行驶跑偏在线自动测试系统的特点,从相机标定精度和稳定性出发,探讨了相机标定算法的选用原则及控制点类型对标定... 相似文献
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开发了一种基于钢板弹簧位移量检测的车载载荷质量检测系统,并应用于大型载货汽车上。对车载载荷检测系统的标定不同于小型汽车,所需要的标准质量大,需要起重机之类的设备,地磅之类大型称重工具。为了简化实施花费,确保标定结果准确,根据钢板弹簧的承载和形变间的关系,对载荷质量求解公式进行了理论推导。根据推导出来的载荷求解公式,并得出了两种随车载荷检测系统的标定方法:轴荷特性拟合法和系数求解法。然后结合标定试验,给出了这两种方法的应用实例,并从标定精度和实施两方面对两种方法进行了对比分析。结果表明,两者的准确性都较高,但系数求解法准确性更高,且实施花费较少,更有利于该技术的普及。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(6):821-856
This article describes the experimental calibration of a three-dimensional numerical model of an Alfa Pendular train vehicle based on modal parameters. The dynamic tests of the carbody and bogie of the vehicle allowed the determination of the frequencies and modal configurations of 13 vibration modes, by applying the data-driven stochastic subspace identification method. In addition, a dynamic characterisation test of the passenger-seat system was also conducted. The calibration of the model was performed using a submodelling/multistep approach involving two phases, the first one focused on the calibration of the model of the bogie under test conditions and the second one focused on the calibration of the complete model of the vehicle. The calibration was performed through an iterative method based on a genetic algorithm and allowed to obtain optimal values of 17 parameters of the numerical model. For the pairing of the vibration modes, real and complex, a recent technique was used based on the calculation of the modal strain energy. The stability of a significant number of parameters considering different initial populations demonstrated the robustness of the algorithm. The comparison of experimental and numerical responses before and after calibration revealed significant improvements in the numerical model and a very good correlation between the responses obtained with the calibrated model and the experimental responses. 相似文献
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This article describes the first application of a novel path flow and origin/destination (OD) matrix estimator for iterated dynamic traffic assignment (DTA) microsimulations. The presented approach, which operates on a trip-based demand representation, is derived from an agent-based DTA calibration methodology that relies on an activity-based demand model (Flötteröd, Bierlaire, & Nagel, 2011). The objective of this work is to demonstrate the transferability of the agent-based approach to the more widely used OD matrix-based demand representation. The calibration (i) operates at the same disaggregate level as the microsimulation and (ii) has drastic computational advantages over conventional OD matrix estimators in that the demand adjustments are conducted within the iterative loop of the DTA microsimulation, which results in a running time of the calibration that is in the same order of magnitude as a plain simulation. We describe an application of this methodology to the trip-based DRACULA microsimulation and present an illustrative example that clarifies its capabilities. 相似文献