Data assimilation into a Princeton Ocean Model of the Mediterranean Sea using advanced Kalman filters

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.     

一种新型的三角形双模带通滤波器的研究

在传统的三角形双模微带带通滤波器的基础上，提出一种新型的双模微带带通滤波器结构，并对该结构及其滤波性能进行研究和分析。利用上述分析结果，设计一个中心频率为2．3GHz的滤波器实物，实测结果和仿真结果基本吻合，验证了研究结果的一致性。     

电力机车四象限辅助变流器的研制

介绍了以四象限辅助变流器为核心的电力机车辅助系统,阐述了该四象限辅助变流器的主电路结构、技术参数和控制系统的设计,通过实验和装车运行证明此系统运行稳定符合设计要求。     

时间对准误差分析实验

分析了滤波过程中预测误差情况，针对这一问题专门进行了数字模拟实验，并对于数字实验的结果进行了分析。     

并行分布式运算FIR滤波器的FPGA实现

研究了2比特并行分布式计算（2-bit PDA）在FPGA中实现了FIR滤波器的应用,并在Altera公司的APEX20K1500E系列FPGA中实现了48阶FIR滤波器,实际结果表明使用该方法实现滤波器不但节省了逻辑单元,而且和普通的并行分布式方法相比还提高了运算速率,从而使该滤波器用于实时信号处理时有更大的优越性.     

基于阿尔法系统的舰船综合导航信息融合方法与仿真

介绍了阿尔法导航系统的特点，提出了一种基于阿尔法信息的舰船综合导航方法，具体阐述了卡尔曼滤波数学模型的建立和滤波实现，并利用Matlab软件进行了仿真和结果分析。     

地下过滤田污水处理生产试验技术经济分析

地下过滤田是土地处理污水的一种形式。它通过铺设在地下的穿孔布水管将污水均匀而又有组织地散布到人工滤料层中,最终缓慢地渗透、扩散到周围土壤中,在经过土壤的过滤、吸附和生化作用后得到净化。为了验证地下过滤系统对生活污水的处理效果,明确地下过滤田的各项经济技术指标     

电力电子系统的无功功率补偿与谐波抑制研究

对电力电子系统的无功功率与谐波抑制方法进行分析。包括谐波的产生、谐波和无功功率的危害、谐波分析的理论基础、非正弦电路的功率，并对并联有源电力滤波器进行了理论分析，对系统加入有源电力滤波器前后利用Matlab／Simulink分别进行仿真研究，比较功率因数和总谐波畸变率，最终满足加入有源电力滤波器后的功率因数接近1，交流侧电流总谐波畸变率小于5％。负载不对称时，加入有源电力滤波器后三相电流完全平衡。仿真结果表明，并联型有源电力滤波器在抑制谐波、补偿无功功率方面具有良好的效果。     

低成本AHRS中Kalman滤波器的降维状态观测器设计

最优控制系统如捷联惯导系统（AHRS）都离不开状态反馈。然而系统的状态变量并不都是易于直接检测到的，这就需要状态观测器。基于减轻导航计算机计算负担和降低成本的考虑，提出Kalman滤波器的降维观测器的设计，并且讨论了误差模型的噪声补偿和降低估值误差的方法。     

基于扩展卡尔曼滤波的船舶纵向运动受扰力与力矩的估计

基于递推最小二乘法设计并实现海浪干扰力和干扰力矩的成型波滤器,对有色的次优卡尔曼滤波和扩展卡尔曼滤波(EKF)的效果进行对比.通过引入成型滤波器,采用EKF,提高了状态估计的精度,实现对随机海浪扰动力和力矩的估计.仿真结果表明,通过扩展卡尔曼滤波对海浪扰动力和力矩进行估计是可行的.