Data reconciliation for input-output models in linear dynamic systems

Sequential data reconciliation algorithms have been developed for input-output models in linear dynamic systems. Existing filtering methods do not treat the case where there are measurement errors in the input variables. In our approach, the measurement errors in the input variables are optimally handled by the least squares method. This method shows good performance for input-output models.     

挤压铸造数值模拟前处理技术研究

开发了一种用于挤压铸造数值模拟的前处理程序,成功应用于挤压铸造壳体的前处理网格剖分.研究了OPen-GL图像处理关键技术,实现了图像的快速绘制,消除了"隐线",得到了优质图象显示.采用"微颤动法"偏移了奇异点,并修补了STL文件的"孔洞"缺陷,实现了对实体均匀网格剖分离散化处理.网格剖分结果表明,该前处理系统是可靠、有效和实用的.     

An imbalance fault detection method based on data normalization and EMD for marine current turbines

This paper proposes an imbalance fault detection method based on data normalization and Empirical Mode Decomposition (EMD) for variable speed direct-drive Marine Current Turbine (MCT) system. The method is based on the MCT stator current under the condition of wave and turbulence. The goal of this method is to extract blade imbalance fault feature, which is concealed by the supply frequency and the environment noise. First, a Generalized Likelihood Ratio Test (GLRT) detector is developed and the monitoring variable is selected by analyzing the relationship between the variables. Then, the selected monitoring variable is converted into a time series through data normalization, which makes the imbalance fault characteristic frequency into a constant. At the end, the monitoring variable is filtered out by EMD method to eliminate the effect of turbulence. The experiments show that the proposed method is robust against turbulence through comparing the different fault severities and the different turbulence intensities. Comparison with other methods, the experimental results indicate the feasibility and efficacy of the proposed method.     

水冷式热管散热器在服务器中的应用研究

为了满足数据中心服务器的散热需求,设计了一种水冷式热管散热器对服务器的CPU进行散热,并搭建服务器测试平台对此散热器的性能进行测试。在不同的CPU负载率η、环境温度Ta、进水温度Tw情况下,对安装了水冷式热管散热器的服务器进行实验研究,得出服务器CPU的温度变化规律。实验结果表明:水冷式热管散热器相对于传统的风冷散热器具有更高的散热效率,散热器的热阻仅为0.0704℃/W。影响水冷式热管散热器散热效果的最主要参数为进水温度,而环境温度对CPU的温度影响相对较小。因此,通过提高环境温度的方法,可以减少数据中心空调设备的热负荷,以达到节能的目的。     

基于条码技术的叶片制造过程质量追溯系统研究

针对企业对产品制造过程质量追溯性的迫切需求,提出了一种基于条码技术的制造过程质量可追溯模式。通过分析叶片制造过程的质量信息和质量追溯数据流程,确定基于条码的质量数据自动采集方案,建立了质量追溯系统的运行模式和体系结构。开发了叶片制造过程质量可追溯系统原型,实现了快速查找质量问题产生的原因,及时发现工艺系统缺陷,采取纠正及预防措施,有效控制产品质量,降低制造成本。     

PDM 与 ERP 物料编码集成设计

针对企业普遍存在的物料编码不统一和数据传递实时性问题,提出了数据集成方法,并介绍了PDM与ERP系统的物料编码集成方案。该方案有效地解决了物料编码的实时传递问题,对企业应用系统的集成具有一定的借鉴意义。     

DSP+FPGA数据处理系统的研究与应用

针对铣削加工中心主轴刚度检测系统实时性的要求。重点阐述了DSP＋FPGA的数字硬件系统和流水线结构的CORDIC算法在FPGA中的实现。并通过仿真和实验对CORDIC算法的理论值和计算数值进行对比分析。结果表明。计算数值非常接近理论值。     

目前我国机械式汽车防盗装置产品现状与质量分析

通过试验室近4年来对汽车防盗装置产品试验数据的统计分析,基本上掌握了目前我国汽车防盗装置采用的主要型式及质量状况,并分析了产品普遍存在的质量缺陷;同时建议汽车生产厂家通过对新技术的研发和应用来提高车辆的防盗功能,从而促进该行业的技术进步。