共查询到20条相似文献,搜索用时 744 毫秒
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在舰船动力装置控制系统中,温度测量设备通常采用铂电阻温度传感器对大量的温度信号进行采集,并将温度信号转换成电阻信号。当这些温度测量设备进行调试、试验时,需要使用电阻器模拟铂电阻温度传感器给出所需的电阻信号。介绍了新型的可编程精密合成电阻以替代传统的电阻箱,该合成电阻采用运算放大器和D/A转换器等器件构成单口网络,通过编程控制输入电压和输入电流的比值获得期望的电阻值。详细分析了该电路误差产生的原因,给出了以ICL7560和AD5543为核心的具体实现电路,其输出电阻误差可控制在0.02Ω以内,对应温度信号在0.05℃以内。该合成电阻具有体积小、精度高、可编程数控的优点,是温度测量设备试验时所需的重要设备。 相似文献
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为规范拱坝施工期温度,本文开展整体浇筑堆石混凝土拱坝施工期温度监测方法的设计研究。根据工程需求,选用温度传感器作为温度监测仪器,按照规范进行仪器设备的选型与埋设布置;考虑到通过温度传感器直接获取的温度数据往往存在各种误差和异常值,因此,在接收仪器设备采集数据后,进行施工期监测温度数据的预处理;通过对拱坝施工期温度场的计算,进行堆石混凝土拱坝施工期温度的监测分析。实例应用实验结果表明,设计的方法监测结果具有可靠性。 相似文献
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基于485总线的温度监控系统设计 总被引:1,自引:1,他引:0
介绍一种基于485总线的温控系统的设计与实现.系统采用上位机和下位机设计,下位机通过温度传感器监测温度,与预置温度比较后执行任务;上位机和下位机通过主从应答方式交换数据信息.在上位机端的PC上实现对多路传感器传来的温度信息入库保存、打印、温度变化历史曲线绘制等功能. 相似文献
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为了提高船舶航行过程信息采集的准确性,减小由于数据采集环境干扰产生的误差,提出船舶航行过程信息分层采集优化算法。在处于航行状态的船舶上安装船舶采样设备,按照信息的不同采样要求构建分布式分层模型。利用安装的船舶航行采样设备,在构建分布式分层模型下,从动态信息层和静态信息层2个方面对船舶航行信息进行分层采集,并将采集到的信息进行模数转换处理,保存最终的数字信息,实现船舶航行过程信息的分层优化采集。经过实验发现,与传统的船舶航行过程信息采集算法相比,船舶航行过程信息分层采集优化算法的平均采集误差率降低了3.43%。 相似文献
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Multigrid state vector for data assimilation in a two-way nested model of the Ligurian Sea 总被引:5,自引:1,他引:4
A. Barth A. Alvera-Azcrate J.-M. Beckers M. Rixen L. Vandenbulcke 《Journal of Marine Systems》2007,65(1-4):41
A system of two nested models composed by a coarse resolution model of the Mediterranean Sea, an intermediate resolution model of the Provençal Basin and a high resolution model of the Ligurian Sea is coupled with a Kalman-filter based assimilation method. The state vector for the data assimilation is composed by the temperature, salinity and elevation of the three models. The forecast error is estimated by an ensemble run of 200 members by perturbing initial condition and atmospheric forcings. The 50 dominant empirical orthogonal functions (EOF) are taken as the error covariance of the model forecast. This error covariance is assumed to be constant in time. Sea surface temperature (SST) and sea surface height (SSH) are assimilated in this system. 相似文献
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目前DGA在线监测系统还存在着元件性能不稳定、抗干扰性能较差、抗外界因素如温度、湿度变化的能力差,造成故障气体的增长性误差比较大,测量数据不稳定等问题。文章利用最小二乘法对误差进行处理,结果显示优化后的数据平稳,可靠性提高。 相似文献
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大功率永磁电机温度场数值计算及实测对比 总被引:3,自引:1,他引:2
温升是考核发电机的一个重要指标。本文首先对常用的几种电机温升计算方法进行了介绍;再以金风科技股份有限公司自主研发的3MW永磁同步发电机为实例,分别采用热路法和有限元方法对其在额定负载条件下的温度场进行了计算,对比误差在5%以内;同时,在3MW电机试验平台上进行了温升试验,将热路法计算结果与实测数据进行了对比,误差也在允许范围内。相比有限元方法,热路法计算温度场的准确性可以接受,同时大大减少计算量与计算难度,可作为永磁电机前期温升设计的校核方法。 相似文献
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Validation of a hybrid optimal interpolation and Kalman filter scheme for sea surface temperature assimilation 总被引:1,自引:0,他引:1
A hybrid data assimilation scheme designed for operational assimilation of satellite sea surface temperatures (SST) into an ocean model has been developed and validated against in-situ observations. The scheme consists of an optimal interpolation (OI) part and a greatly simplified Kalman filter (KF) part.The OI is performed only in the longitudinal and latitudinal directions. A climatological field is used as a background field for the interpolation. It is constructed by fitting daily averages of satellite SST to the annual mean, annual, and semiannual harmonics in a 20 km by 20 km grid. The background error covariance is approximated by a spatially varying two-dimensional exponential covariance model. The parameters of the covariance model are fitted to the deviations of the satellite data from the background field using data from a full year.The simplified KF uses ocean model forecasts as a background field. It is based on the assumption that it is possible to neglect horizontal SST covariances in the filter and that the typical time scale for vertical mixing in the mixed layer is much shorter than the average time between observations. We therefore assume that the error variance in a column of water is evenly spread out throughout the mixed layer. The result of these simplifications is a computationally very efficient KF.A one year validation of the scheme is performed for year 2001 using an operational eddy resolving ocean model covering the North Sea and the Baltic Sea. It is found that assimilation of sea surface temperature data reduces the model root mean square error from 1.13 °C to 0.70 °C. The hybrid scheme is found to reduce the root mean square error slightly more than the simplified KF without OI to 0.66 °C. The inclusion of spatially varying satellite error variances does not improve the performance of the scheme significantly. 相似文献
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建立两种数据模型:基于LabVIEW平台的参数测试系统观测数据模型和理想数据模型。以此模型为基础,分析数据中的系统误差和研究系统误差的检验方法,提出了基于后验检验统计的系统误差检测法。讨论了随机误差的分布、测度。最后修改观测数据的模型,结合此模型研究系统误差和随机误差的评定指标。 相似文献
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Data assimilation into a Princeton Ocean Model of the Mediterranean Sea using advanced Kalman filters 总被引:1,自引:0,他引:1
This study investigates the effectiveness of the Singular Evolutive Extended Kalman filter (SEEK) and its variants (SEIK and SFEK filters) for data assimilation into a Princeton Ocean Model (POM) of the Mediterranean Sea. The SEEK filters are sub-optimal Kalman filters based on the approximation of the filter's error covariance matrices by singular low-rank matrices, reducing in this way extensive computational burden. At the initialization, the filters error covariance matrix is parameterized by a set of multivariate empirical orthogonal functions (EOFs) which describe the dominant modes of the system's variability. The Mediterranean model is implemented on a 1/4° × 1/4° horizontal grid with 25 sigma levels and is forced with 6-hour ECMWF re-analysis atmospheric data. Several twin experiments, in which pseudo-observations of altimetric data and/or data profiles were assimilated, were first performed to evaluate the filters performances and to study their sensitivities to different parameters and setups. The results of these experiments were very encouraging and helped in setting up an effective configuration for the assimilation of real data in near-real time situation. In the hindcast experiments, Topex/Poseidon and ERS weekly sea level anomaly data were first assimilated during 1993 and the filters solution was evaluated against independent Reynolds sea surface temperature (SST) analysis. The assimilation system was able to significantly enhance the consistency between the model and the assimilated data, although the improvement with respect to independent SST data was significantly less pronounced. The model SST was only improved after including SST data in the assimilation system. 相似文献
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氮氧化物选择性催化还原开环控制技术误差分析 总被引:1,自引:0,他引:1
为了解不同影响因素对氮氧化物选择性催化还原开环控制技术误差的影响程度,推导氮氧化物选择性催化还原开环控制技术误差的理论表达式,试验表明原机排放相对误差对氮氧化物选择性催化还原开环控制技术误差的影响比尿素水溶液浓度相对误差和计量装置相对误差产生的影响大。 相似文献
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为了实现对船用微型锅炉高、低水温的控制,在Matlab环境下对实测和计算的数据进行曲线拟合,建立了船用微型锅炉水温系统的非线性数学模型。运用滑模变结构控制理论,选取线性切换面和比例型趋近率,设计了一种滑模控制器,实现了双输入双输出非线性耦合温度系统的解耦和控制。通过Matlab/Simulink软件的仿真,结果显示滑模变结构控制算法对非线性系统的控制有响应快、超调小、调节时间短、无误差和抖动的特点。 相似文献