基于双轴位置转台的捷联惯导系统级标定技术

本文研究一种基于双轴位置转台的激光陀螺捷联惯导系统的系统级标定方法。建立了附加约束条件的陀螺和加速度计标定模型,从捷联惯导系统的误差方程出发,建立30维Kalman滤波标定模型,以速度和位置作为观测量,并设计双轴位置旋转路径,对惯性仪表标定参数进行激励与辨识。仿真实验结果表明,该方法能够准确估计出陀螺和加速度计的15个标定误差参数,具有一定的参考价值。     

系泊状态舰载捷联惯导系统的全参数在线标定

为了满足在舰标定的需求,提出了一种舰载捷联惯导系统在系泊状态下的全参数在线标定方法。首先建立了陀螺和加速度计的输出误差方程。然后给出了误差参数标定Kalman滤波模型,该模型以陀螺和加速度计零偏、安装误差、标度因数误差等24个误差量为状态量。设计了低通滤波器从捷联惯导解算速度中获取速度解算误差作为量测量。设计了一种合理的标定路径,提高了状态量的可观测度。通过对IMU转位数据进行导航滤波处理,估计出全部参数。仿真试验和实物摇摆试验表明,该方法能够准确地估计出全部参数,具有工程实践价值。     

基于双轴速率转台的IMU440惯性测量单元快速标定方法与实验

在捷联惯导系统中,惯性器件的确定性误差是系统误差的主要原因之一。为了提高惯导系统的输出精度,必须对这一误差加以补偿。以美国Crossbow公司开发的IMU440惯性测量单元为对象进行了快速标定实验,建立了陀螺仪和加速度计的误差模型方程,提出了用于辨识陀螺仪和加速度计误差模型参数的速率和位置标定法,根据两种标定方法得到了IMU440惯性测量单元的误差模型,最后对误差模型进行了校验。实验结果表明,误差补偿后的惯性器件输出值可以很好地接近理想输出值,大大降低了捷联惯导系统的输出误差。     

船用捷联惯性系统的IMU测量模型优化研究

为了提高捷联系统惯性测量组件(IMU)的测量精度,在建立完整的惯组测量数学模型的基础上,采用逐步回归法对测量模型的自变量选择进行最优化选择,寻优时用复相关系数R2作衡量测量方程优劣的指标.试验结果表明,在陀螺测量模型中,角速度二次交叉耦合项系数和与比力的二次项系数非常小,加速度计的测量模型中的加速度二次耦合项系数也很小,模型加入该组变量后,R2变化并不大,均可以忽略不计.采用逐步回归分析法从众多的影响因素中,挑选对响应变量贡献大的因素,从而建立了惯组最优化测量模型.     

基于迭代计算的加速度计标定方法

在建立三轴加速度计数学模型的基础上,提出了一种新的三轴加速度计的标定算法.加速度计在静止状态下,各敏感轴分量的模值等于当地重力加速度的数值.通过六个不同静态位置加速度计的输出建立标定方程.采用迭代算法对加速度计的标度因子和零偏进行解算.仿真结果表明,算法能够有效标定出加速度计误差参数,并且对较大偏差的初值同样适用,且迭代过程收敛迅速,计算量小,非线性适应性较强,能够拓展标定算法的应用范围.     

基于迭代计算的加速度计标定方法

在建立三轴加速度计数学模型的基础上,提出了一种新的三轴加速度计的标定算法。加速度计在静止状态下,各敏感轴分量的模值等于当地重力加速度的数值。通过六个不同静态位置加速度计的输出建立标定方程。采用迭代算法对加速度计的标度因子和零偏进行解算。仿真结果表明,算法能够有效标定出加速度计误差参数,并且对较大偏差的初值同样适用,且迭代过程收敛迅速,计算量小,非线性适应性较强,能够拓展标定算法的应用范围。     

空泡及分离尾流对细长回转体附加质量影响的试验研究

带空泡航行体的附加质量是个国际上还没有解决的问题，为了预测细长体在带空泡航行时的水下轨迹，工程上必须解决空泡对附加质量λ２２的影响这一实际工程问题，为此，本文针对三种没模型进行了带空泡航行时的附加质量的试验研究。试验是用振动翼机构在中国船舶科学研究中心０３Ａ空泡水筒上实现的，采用与平面运动机构相类 的数据处理方法分离邮模型作横荡运动时的附加质量和位置导数。变化水筒中的水束或空泡数，可得到附另质量和     

外弹道数据处理专家系统模型分析与设计

结合靶场试验外弹道数据处理工作实际,分析了外弹道数据处理专家系统的结构,提出运用误差诊断模型及数据统计原理建立靶场数据处理决策专家系统和测控设备状态评估专家系统模型,并给出外弹道数据处理专家系统模型设计思路,可为各类试验数据处理方案和外场试验布站方案的制定提供依据.     

一种航行体水弹道的数值仿真与试验研究

针对一种航行体复杂的水弹道特性,对流固耦合数值计算方法进行分析,并在此基础上采用MSC.DYTRAN有限元分析软件建立起航行体水弹道仿真计算模型,应用该模型计算得到航行体水中运动规律。研究了水弹道缩比试验相似准则及测试方法,开展多发次缩比试验获取了航行体水弹道特性。仿真计算和缩比试验结果的对比分析表明二者一致性较好,试验和计算方法能够为相似研究提供指导。     

潜射导弹燃气蒸汽式发射装置的内弹道建模

发射过程中的内弹道建模是潜射导弹变深度发射的关键技术之一。按冷却水状态将燃气—蒸汽式发射装置发射过程分为4个阶段,本文主要针对各阶段的内弹道进行理论分析和建模,得出了整个发射过程中发射筒内的内弹道模型。将该内弹道模型应用于某实例,计算结果和实验结果吻合较好,这表明该内弹道模型具有一定的准确性和实用性,一定程度上可以预示发射筒内工质气体的状态参数及导弹运行参数。     

Using the SKAGEX dataset for evaluation of ocean model skills

Numerical ocean models are now being applied in numerous oceanographic studies. However, the qualities of the model results are often uncertain and there is a great need for standards and procedures for evaluation of the skills of numerical general circulation models. In this paper measurements from repeated hydrographical sections across Skagerrak taken in 1990, the SKAGEX dataset, are used to evaluate the skills of two σ-coordinate ocean models and to study the sensitivity of these models to model parameters. A methodology for quantification of model skills based on observations from repeated hydrographical sections in general is suggested. Area averages of absolute differences are for Skagerrak completely dominated by the discrepancies in the upper few meters of the ocean and may not be used to assess models' abilities to reproduce the fields in the larger and deeper part of the ocean. Therefore, discrepancies between average values in time from the observed fields and time averaged values from model outputs are related to the natural variability of the fields. The numbers produced with the suggested measure are relative numbers that will be specific for each section and for each series of observation. Ideally we would therefore like to see the measures computed for a number of sections for various models and choices of model parameters in order to assess model skills. The value of the SKAGEX dataset as a tool for model improvements is demonstrated. Evidence to support the importance of applying non-oscillatory, gradient preserving advection schemes in areas with sharp density fronts is given. The method is used to identify that the forcing/initial values/boundary values for the temperature field are inferior to the corresponding values for the salinity field. With the present coarse resolution, 11 layers in the vertical, it is shown that it is far from obvious that the quality of the model results improve when replacing simple Richardson number formulations for vertical mixing processes with higher order turbulence closure in the Skagerrak area.     

源识别方法在实艇水下噪声数据分析中的应用

本文对多点同步测量方法记录的舰艇噪声数据,采取在时域上作滤波、时延补偿和互相关得到输入输出协方差矩阵,然后从输入输出协方差矩阵计算在网络意义和偏相干意义下输入对输出的贡献以及其它有用的量。     

船用蝶阀液压控制系统的数值仿真

液控蝶阀以其启闭扭矩大、压力损失小和适合用于大中口径管道等特点,在船舶领域得到了广泛应用。基于船舶中某一常用规格的中线对称阀瓣的液控蝶阀,建立该液控蝶阀在实际工况下启闭控制液压系统的数学模型,并进行数值仿真和试验研究。仿真及试验结果表明:液控蝶阀启闭时的转动角速度及其误差受蓄能器排油量、管路压力损失、液压介质的温度以及液控蝶阀的负载影响较大。这一仿真分析及试验结果可为蝶阀液压控制系统中蓄能器总容量和管路通径的选择、液控蝶阀结构型式和规格的确定及其所输送流体运动参数的设计提供依据。     

平板与周期加筋阻尼板间耦合损耗因子的研究

耦合损耗因子是统计能量分析中唯一用于表征耦合系统间能量交换的重要参数,本文在波传递理论基础上,分析了周期加筋阻尼板的波传播特性：即对于周期加筋阻尼板无论是在波的传播域,还是在波的衰减域都减域缩小。结合统计能量分析法,讨论了加强筋宽度、材料阻尼对耦合损耗因子的影响,得到了增加加筋板阻尼损耗因子,使平板至加筋板的耦合损耗因子增大的结论。     

尺度作用与阻力系数的相关分析

在船模试验和分析的基础上,提出了船模阻力的换算为实船阻力时可应用相关阻力系数的方法。相关系数法综合考虑了实船和船模的粗糙度和船模的尺度效应,因此其估算的实船阻力具有较高的精度。     

一种船模和实船试验中的船舶运动测量系统

开发了一套耐波性船模和实船试验中测量船舶运动的系统,该系统由加速度传感器、角速率陀螺和数据分析、处理软件组成。在数据处理过程中,采用一种非线性迭代算法。对该测量系统进行了水池模型试验和实船试验的验证,也利用三自由度运动平台进行了比测,比较结果令人满意。本装置是一种可靠性好、成本较低的船模和实船在波浪中运动测量系统。     

Forecasting the Suez Canal traffic: a neural network analysis

Although the Suez Canal is the most important man-made waterway in the world, rivaled perhaps only by the Panama Canal, little research has been done into forecasting its traffic flows. This paper uses both univariate ARIMA (Autoregressive Integrated Moving Average) and Neural network models to forecast the maritime traffic flows in the Suez Canal which are expressed in tons. One of the important strengths of the ARIMA modelling approach is the ability to go beyond the basic univariate model by considering interventions, calendar variations, outliers, or other real aspects of typically observed time series. On the other hand, neural nets have received a great deal of attention over the past few years. They are being used in the areas of prediction and classification, areas where regression models and other related statistical techniques have traditionally been used. The models obtained in this paper provide useful insight into the behaviour of maritime traffic flows since the reopening of the Canal in 1975—following an 8-year closure during the Arab–Israeli wars (1967–1973)—till 1998. The paper also compares the performance of ARIMA models with that of neural networks on an example of a large monthly dataset.     

Forecasting the Suez Canal traffic: a neural network analysis

Although the Suez Canal is the most important man-made waterway in the world, rivaled perhaps only by the Panama Canal, little research has been done into forecasting its traffic flows. This paper uses both univariate ARIMA (Autoregressive Integrated Moving Average) and Neural network models to forecast the maritime traffic flows in the Suez Canal which are expressed in tons. One of the important strengths of the ARIMA modelling approach is the ability to go beyond the basic univariate model by considering interventions, calendar variations, outliers, or other real aspects of typically observed time series. On the other hand, neural nets have received a great deal of attention over the past few years. They are being used in the areas of prediction and classification, areas where regression models and other related statistical techniques have traditionally been used. The models obtained in this paper provide useful insight into the behaviour of maritime traffic flows since the reopening of the Canal in 1975—following an 8-year closure during the Arab-Israeli wars (1967-1973)—till 1998. The paper also compares the performance of ARIMA models with that of neural networks on an example of a large monthly dataset.     

大型船舶横向靠离码头所需拖船协助力的近似计算

为了保证大型船舶安全、经济地靠离码头，驾引人员应当对所需拖船协助力心中有数。国内外研究人员已在理论和实验方面做了大量的工作，但实用的计算方法仍不多见，且存在着一些问题。提高大型船舶横向靠离码头所需拖船协助力估算精度的关键是横流阻力系数Ｃ（ｗｙ）的估算。该文根据１２条船模试验数据用逐步回归分析法获得了可以表达Ｃ（ｗｙ）与船型及水深之间关系的近似公式；同时依据大型船舶横向离码头实际是加减速运动这一事实，考虑了加速运动对Ｃ（ｗｙ）系数的影响；此外还分析了岸壁对船舶横向运动的影响。该文所提供的计算方法是实用和可靠的，可供船舶驾引人员使用，亦可供船舶操纵运动数学模型研究人员参考。     

Violation or strengthening of the self-financing doctrine at international airports by SMCP funded PPP schemes?

International airports are among the few examples of transport infrastructures which can well achieve self-financing. The growing interest of private companies in airport construction and operation is the visible testimony to this fact. However, the financing structures of airports are complex, involving not only traffic, passenger and goods handling, but also non-aviation services, such as retail, car parking or intermodal facilities. The integration of social marginal cost pricing schemes into this organizational structure according to the strategic plans of the European Commission, however, is challenging. This paper investigates whether they comply with a second strategic policy objective at European and national level, which is to foster public-private partnerships (PPPs) in transport financing in terms of full cost coverage, risks and incentives.The cases analysed in this paper deal with two sites with very different characteristics: Munich Airport which has been publicly operated since 1991 and the Bulgarian airports Varna and Burgas, which have been managed since 2007 by one concessionaire and whose planning and future development is being accomplished with private capital. The results of both cases showed that self-financing is possible in case congestion costs are considered in the SMCP schemes, and given that air traffic growth rates return to the significant levels prior to the economic crisis. The chapter will discuss the legal implications of congestion pricing at European airports which are violating current EC legislation, as well as the impact of alternative pricing schemes on the environmental performance and technological innovation in aviation.