一种数字式静电陀螺仪测角系统

该文就静电陀螺仪对极轴位置分辨率和稳定性的高要求 ,研究了一种数字式测角系统。这一系统基于球形转子赤道面上的锯齿图谱 ,采用光学传感器拾取信号 ,通过信号处理电路 ,将转子的极轴位置信号转换为数字脉冲信号的数字式测角系统。文中探讨了此数字式测角系统的方案 ,介绍了新研制的信号处理电路 ,并进行了测角试验 ,给出了系统精度。     

基于差动电容和变压器电桥的陀螺转子偏移测量研究与影响因素分析

利用超导体的Meissner效应实现转子悬浮的超导陀螺转子会因为各种原因而偏离球腔中心,准确测得转子的偏移并使转子稳定在球腔中心,成为实现陀螺转子超导支承的关键。文章首次提出了基于差动电容传感器与变压器电桥的超导陀螺转子的偏移测量方案并给出了各参数之间的关系,该方案能同时测量出转子偏移的大小和转子偏移的方向。然后着重分析了影响陀螺转子偏移测量精度的因素并给出了各种因素综合影响实例的仿真结果,指出差动电容传感器的分布电容、陀螺转子的零电位、模型误差等是影响测量精度的主要因素,提出了降低不利影响的方法和模型适应范围,从而使输出电压与转子偏移量间呈较好的线性关系。     

MIMU/GPS/磁传感器组合导航系统信号处理

针对MIMU/GPS/磁传感器组合导航系统,进行了GPS信号调理、MEMS陀螺仪降噪以及磁传感器误差补偿研究。用双线性趋势外推法与MIMU陀螺仪信息对GPS信号进行处理,用AR（3）误差模型对MEMS陀螺仪去噪建模,用旋转标定方法对磁传感器进行误差补偿。通过对自行研制的MIMU/GPS/磁传感器组合导航系统与高精度组合导航系统的室外跑车比对试验,验证了上述信号处理及误差补偿方法的有效性。     

感应电机转子断条故障诊断方法研究进展

转子发生断条故障后,电机的电流信号中将会出现故障特征频率分量。而基于定子电流信号分析的故障诊断方法可以做成非侵入式,结构简单,数据采集方便,因此是该方向研究的热点。总结了近年来基于定子电流信号分析的转子故障诊断方法,并对进一步的研究进行了展望。     

GMSK调制器在电力线通信中的实现

本文就GMSK（最小高斯频移键控）调制的原理,给出了一种全数字实现结构并在FPGA上加以实现。仿真结果表明,这种数字实现结构产生GMSK基带信号具有良好的功率谱及眼圈,且能够有效避免I／Q两条支路信号幅度及正交载波相位失衡。     

基于加权矢量神经网络的辐射源识别方法

现有的很多分类识别方法包括基于专家系统的方法[1]、基于贝叶斯理论的方法、基于模糊模式识别的方法[2]、基于最近邻的方法[3]、基于人工神经网络的方法[3]等等在辐射源识别中都有比较成功的应用,但这些方法一般都针对测量参数为标量形式的测量值进行处理,在一定程度上解决了由于参数测量误差所引起的辐射源识别问题,对于误差的另一种情形,即测量参数为区间类型模糊值的情况讨论却较少,文献提出了一种基于模糊IF-Then规则的神经网络算法,给出了能够处理模糊输入的神经网络体系结构,同时给出了一种基于代价函数的学习算法,其代价函数由实际模糊输出和无模糊输出决定,通过学习该网络能够实现模糊输入到模糊输出的非线性映射。     

基于序贯代理模型的转子系统频响特性区间分析方法

在转子系统的频率响应分析中,不确定性广泛存在,并且对分析结果有较大的影响。本文提出了一种面向含区间不确定性转子系统频响分析的序贯代理模型方法。基于区间数学以及转子动力学理论,本文首先建立了含区间参数转子系统频响的控制方程。基于传统的静态代理模型提出了面向转子系统区间分析的序贯代理模型方法。该方法首先通过叫少量的样本点构造粗糙代理模型,再提出了两个指标函数进行下一阶段的选点。重复该过程,直到满足收敛条件,最终可以得到转子系统频率响应的精细代理模型,进而得到区间边界。和传统的区间分析方法相比,该方法精度高,适合非线性问题。     

基于高频方波注入的船舶电机无传感器控制研究

随着大功率交流调速技术的不断进步,船舶电力推进如今成为船舶行业的主要发展目标.为研究运行可靠稳定、灵活、高性能的船舶电机无位置传感器控制,系统采用高频注入法估算电机转子位置信号,根据基于高频注入永磁同步电机数学模型的研究,该系统中高频采用的是高频方波注入,减少滤波器的使用从而缓解了转子位置延迟现象,同时采用锁相环对电机转子的相位和频率跟踪来计算电机转子的估计转速,克服了估算转速脉动大的困难.利用Matlab对电机控制系统仿真,验证电机控制系统的电机转速平滑稳定,转子位置波形在0-2π有规律往返.最终实现高精度、灵活的无传感器船舶电机控制.     

燃气轮机转子支承刚度计算研究

综合归纳燃气轮机转子的各种支承结构形式、特点,剖析结构参数对支承刚度的影响。针对燃气轮机转子在高转速下支承刚度获取难的问题,运用理论分析和经验公式相结合的方法,对某型燃气轮机转子支承进行刚度计算与误差分析。结果表明,对于弹性阻尼支承系统,刚度值在一定精度范围内的初步计算可不考虑油膜刚度的影响。     

测试系统中波形的神经网络识别方法

为满足自动测试系统对信号波形的智能化识别要求,在对现有的波形识别方法进行研究的基础上,提出一种新的波形识别方法;该方法在利用离散余弦变换（DCT）对波形进行频域特征提取的基础上,将模式识别与BP神经网络理论相结合从而建立波形特征匹配模板,最终实现对信号波形的智能识别;对比试验表明,该方法与最大相关系数法（MCC）、最大相关差值法（MCD）相比很好地解决了待测波形与模板波形匹配过程中的相位对齐过程,而且更加快速、高效。     

船体与组合推进器水动力相互干扰特征的模型试验及推力减额特性的评估分析

以船体、导管和前置定子及转子组成的系统的推力减额特性为研究对象,基于因子分析理论,提出了该三因子系统的水动力相互干扰分析模型,导出了诸因子之间相互影响的求解公式,并采用分解试验方法实现了所有效应的准确测定.分析研究了系统推力减额的两种不同处理方式,建立了相应的评价指标体系.通过对两个特定方案的评估分析,推荐采用k2和t2作为系统推力减额性能优劣的综合评价指标,并建议采取以减小RrlH和RrlSD为主要方向的优化策略.     

Analysis of unsteady flow over Offshore Wind Turbine in combination with different types of foundations

Environmental effects have an important influence on Offshore Wind Turbine (OWT) power generation efficiency and the structural stability of such turbines. In this study, we use an in-house Boundary Element (BEM)—panMARE code—to simulate the unsteady flow behavior of a full OWT with various combinations of aerodynamic and hydrodynamic loads in the time domain. This code is implemented to simulate potential flows for different applications and is based on a three-dimensional first-order panel method. Three different OWT configurations consisting of a generic 5 MW NREL rotor with three different types of foundations (Monopile, Tripod, and Jacket) are investigated. These three configurations are analyzed using the RANSE solver which is carried out using ANSYS CFX for validating the corresponding results. The simulations are performed under the same environmental atmospheric wind shear and rotor angular velocity, and the wave properties are wave height of 4 m and wave period of 7.16 s. In the present work, wave environmental effects were investigated firstly for the two solvers, and good agreement is achieved. Moreover, pressure distribution in each OWT case is presented, including detailed information about local flow fields. The time history of the forces at inflow direction and its moments around the mudline at each OWT part are presented in a dimensionless form with respect to the mean value of the last three loads and the moment amplitudes obtained from the BEM code, where the contribution of rotor force is lower in the tripod case and higher in the jacket case and the calculated hydrodynamic load that effect on jacket foundation type is lower than other two cases.     

“十字”鸭舵控制低旋尾翼弹方法研究

某制导弹药采用鸭式布局,执行机构为两对对称且垂直安装的“十字”鸭舵.论文根据“十字”鸭舵结构和特点,研究了由弹体转速、滚转姿态角和理论控制力求解两对舵实时舵偏角的方法,并进行试验验证,解决了“十字”鸭舵如何实现低旋转尾翼稳定弹所需的控制合力问题.     

助飞式水声对抗器材落点测量方法及误差分析

助飞式水声对抗器材落点精度海上试验因海况、测量手段等因素限制一直是试验的重难点问题。本文从分析助飞式水声对抗器材基本工作原理和其落点精度影响因素入手,即光学定位法、水声定位法、人工定位法和遥测定位法四种落点精度海上试验的测量方法。对四种测量方法的优势、劣势进行了对比分析,提出了一种基于Matlab软件的数据处理方法,并对测量结果的误差进行了对比分析,综合提出了根据海上试验环境条件和测量保障条件进行海上试验的优选原则。     

基于小波降噪的经验模式分解方法研究

通过正常工况下的转子位移信号,分析不同幅值噪声对经验模式分解(EMD)分解的影响。对于幅值较小的随机噪声,EMD分解可以自适应地将主要特征信息从噪声中分解出来。而对于幅值较大的噪声,小波降噪的EMD分解则可以有效避免模态间能量泄漏,从而得到准确的分析结果。     

Multivariate assimilation in MERCATOR project: New statistical parameters from forecast error estimation

The new operational prototype of Mercator (french Global Ocean Data Assimilation Experiment contribution) is composed of a North Atlantic primitive equation ocean model OPA (Ocean Parallel Algorithm between 20°S and 70°N, [Madec, G., P. Delecluse, M. Imbard and C. Lévy (1998). OPA8.1 ocean general circulation model reference manuel. Notes du pôle de modélisation IPSL. n°11: 91p]) and of a multivariate and multidata assimilation scheme [De Mey, P. and M. Benkiran (2002). “A multivariate reduced-order optimal interpolation method and its application in Mediterranean basin-scale circulation.” Ocean Forecasting : Conceptual basis and application, Pinardi, N., Springer Verlag.] This system has already given some significant improvements from previous Mercator configurations (M. Benkiran, personal communication). However some biases on ocean state still remain in the tropics where the reduced-order optimal interpolation scheme is suspected to be ill-parameted in the model forecast error. Indeed the guess error covariance matrix is decomposed into an error variance value and a spatio-temporal correlation function which are assumed to have some “good” properties (spatial homogeneity of the correlation function, constant ratio between signal and error variance). This study shows how we can use ensemble methods to validate these assumptions. We can see that the correlation function can reach negative values locally, mostly in regions of high variability contradictory with the homogeneous hypothesis. The reduced space used in the operational configuration is based on the signal seasonal Empirical Orthogonal Functions (EOFs). An empirical relationship between signal and error variance has been set and the correlation function is the same on every dimension of the reduced space. By projection of the estimated guess error variance onto the reduced space, we find a repartition of this quantity quite different to what was set in the system. The error statistics is found to be inhomogeneous compared to hypothesis made in the assimilation scheme. These two new parameters tested separately in the assimilation scheme gives significant improvements of the forecast and analysis results. This is particularly obvious in the tropics. But relationship between signal and error statistics (as assumed in the optimal interpolation) is found to be complex.     

陀螺转子形状及变形分析和对陀螺性能的影响

介绍了新型陀螺仪转子的一些结构特性和材料组成。分析了会引起转子表面形变的几种因素,利用小波有限元方法根据工作环境对陀螺转子进行了离心变形、温度变形、压力变形以及这三种载荷下的耦合变形进行了仿真分析,分别给出了转子的形变分布矢量图。提出由于光子压力而产生的变形但没有定量分析,最后分析了由于转子的变形的而使转子表面不规则对陀螺性能产生的负影响,可以用这些参数来预测陀螺漂移性能,也可以通过数学方法来补偿由于转子表面形变而带来的干扰力矩,也为转子的设计和进一步优化提供了重要的参考依据。     

Prediction of steel plate deformation due to triangle heating using the inherent strain method

In a shipyard, line heating and triangle heating are two major processes carried out by skilled workers to form curved plates in various shapes under various heating conditions. There have been many studies on line heating, but triangle heating has rarely been studied owing to its complicated heating process with irregular multiheating paths and highly concentrated heat input. Triangle heating is the most labor-intensive job. Hence, it is essential for most shipyards to study the automation, as well as the improvement, of the triangle heating process in order to increase hull-forming productivity. In this study, a pioneering attempt to simulate triangle heating was made. A circular disk-spring model is proposed as an analysis model for the elastoplastic procedure of triangle heating, and the inherent strain method is also used to analyze the deformation of plates. The results of the simulation were compared with those of experiments and showed good agreement. It is shown that the present approach and the model used in this study are effective and efficient for simulating triangle heating for the steel plate forming process in shipbuilding.     

反鱼雷鱼雷自导导引弹道方法研究

论文根据反鱼雷鱼雷的作战需求,在基于反鱼雷鱼雷传统的比例导引法上,对比例导引法进行修正,降低比例导引算法的误差。并通过对反鱼雷鱼雷作战模式的研究,提出新的预测弹道方法。同时通过仿真分析,得出此两种导引方法用于反鱼雷鱼雷的弹道轨迹,偏航角以及脱靶量,为反鱼雷鱼雷拦截弹道的设计提供了一定的思路。     

陀螺壳体旋转监控技术

陀螺壳体旋转法监控技术有助于提高平台罗经系统精度、减少陀螺漂移与加速度计误差。本文首先介绍了该项技术的应用背景；详细阐述了系统结构特性、基本工作原理、机械编排与稳定回路，以及实现方法；本文深入研究了旋转平台转速的选取方法并分析了系统误差；最后计算了典型情况下旋转壳体的转速。结果表明：采用陀螺壳体旋转法监控技术可以有效地调制陀螺漂移、从理论上可提高陀螺仪精度二至三个数量级，从而使平台罗经系统精度得到很大的提高。