Experiment automation using digital signal processing methods

Theoretical methods and algorithms of digital signal processing (DSP), as well as certain approaches to practical implementation of the experiments in industrial and laboratory measurements and tests are considered, based on utilization of ZETLab hardware-software complex. An example of real-time evaluating the spatial coordinates for the source of low-intensity vibration (noise disturbance) is provided. The concept of virtual device (VD) serves as the foundation in planning and implementing the experiment; note that the actual hardware components, i.e., seismometers and analog-to-digital converters (ADC), are involved in the process, having PC interface as a certain link among the measurement object, mathematical framework and operator. The suggested method of coordinate evaluation operates according to the logic based on spectrum and correlation analysis of the signals, with subsequent data visualization via reciprocal projection technique.     

Low power architectures for digital signal processing

Low power architectures for digital signal processing algorithms requiring inner product computation are presented. In the first step a power efficient memory organization exploiting data reuse is determined. In the second step an order of evaluation of the partial products that reduces the switching activity at the inputs of the computational units is derived. Information related to both coefficients which are static and data which are dynamic, is used to drive the reordering of computation. Experimental results for several signal processing algorithms prove that the proposed techniques lead to significant savings in net switching activity and thus in power consumption.     

分布式光纤测温系统及高速数据采集与处理

分布式光纤测温系统是一种用于实时测量空间温度场分布的传感器系统。介绍了一种以数字信号处理器(DSP)为核心,以并行高速流水线式A/D转换器、先入先出队列芯片(FIFO)、可编程逻辑器件(CPLD)为主体的分布式光纤测温系统。其数据采集速率每秒可达10×107次,空间分辨力达1m,温度分辨力为1℃,并能直接在主机中解调出温度数据。     

Data acquisition for real-time process control systems

A general scheme for signal sampling is presented, which is based on requirements of real-time systems. Instead of the ideal low-pass filter in Shannon's sampling theorem, alternative filters are derived from wavelet theory. To evaluate the filters, digital simulations have been carried out. The results of these simulations are briefly discussed in this paper. Finally, some remarks are made on the implementation of the alternative sampling methods and their usage for process control systems.     

Analog VLSI systems for image acquisition and fast early vision processing

This article describes a project to design and build prototype analog early vision systems that are remarkably low-power, small, and fast. Three chips are described in detail. A continuous-time CMOS imager and processor chip uses a fully parallel 2-D resistive grid to find an object's position and orientation at 5000 frames/second, using only 30 milliwatts of power. A CMOS/CCD imager and processor chip does high-speed image smoothing and segmentation in a clocked, fully parallel 2-D array. And a chip that merges imperfect depth and slope data to produce an accurate depth map is under development in switched-capacitor CMOS technology.     

Spectral observation of power network signals for digital signal processing

A fast digital signal processing algorithm with a view to digital protection of power networks using a dead-beat spectral observer is presented. The spectral observer computes the discrete Fourier transform of a sampled-data band-limited periodic signal (like the differential currents in power transformers and voltages, and currents in power transmission lines) recursively to produce high-speed fault detection. Further progressive incorporation of new samples, discarding the old ones as in running Fourier transforms, requires a single iteration. The scheme is suitable for microprocessor-based realtime application and has been implemented on line with a 16-bit LS1-11/23 microcomputer with signals from a power transformer.     

电力物联网的数据采集系统与网络传输

阐述了电力物联网的数据采集系统模型以及数据采集的网络传输方式,给出了电力系统数据采集网络设计与数据采集网络的实现方法。     

基于盘点机的生产现场数据采集及处理系统

针对生产现场基础数据的采集、传递、（预）处理操作,提出了基于盘点机的自动识别、处理方法。首先,基于各部门间对基础数据处理过程的需求分析,构建了系统实施框架,并以条形码为标识,进行信息编码设计。其次,划分了系统的各功能模块,并进行了详细流程分析,在此基础上,采用HTBase语言在盘点机上开发了数据采集及处理系统。实现了在生产现场通过盘点机对成品的采集、组码、修改、查询、确认及传递等功能,为企业资源管理系统提供实时、准确、可靠数据。     

Mental workload measurement for emergency operating procedures in digital nuclear power plants

Mental workload is a major consideration for the design of emergency operation procedures (EOPs) in nuclear power plants. Continuous and objective measures are desired. This paper compares seven mental workload measurement methods (pupil size, blink rate, blink duration, heart rate variability, parasympathetic/sympathetic ratio, total power and (Goals, Operations, Methods, and Section Rules)-(Keystroke Level Model) GOMS-KLM-based workload index) with regard to sensitivity, validity and intrusiveness. Eighteen participants performed two computerised EOPs of different complexity levels, and mental workload measures were collected during the experiment. The results show that the blink rate is sensitive to both the difference in the overall task complexity and changes in peak complexity within EOPs, that the error rate is sensitive to the level of arousal and correlate to the step error rate and that blink duration increases over the task period in both low and high complexity EOPs. Cardiac measures were able to distinguish tasks with different overall complexity. The intrusiveness of the physiological instruments is acceptable. Finally, the six physiological measures were integrated using group method of data handling to predict perceived overall mental workload.

Practitioner Summary: The study compared seven measures for evaluating the mental workload with emergency operation procedure in nuclear power plants. An experiment with simulated procedures was carried out, and the results show that eye response measures are useful for assessing temporal changes of workload whereas cardiac measures are useful for evaluating the overall workload.     

Research laboratory for fish processing automation

This paper outlines the organization, resources, and research and development activities of a newly established laboratory for industrial automation at a major Canadian university. The laboratory has been established in the Department of Mechanical Engineering primarily to support the research and development activities associated with the Natural Sciences and Engineering Research Council (NSERC) Chair of Industrial Automation. The research is focused on the development of advanced and low-cost technology for flexible automation of the fish processing industry. The main objective is to upgrade the technology used in the mechanical processing of fish, thereby reducing wastage of the primary product, improving efficiency, and making the local industry more competitive in export markets. Establishment of an infrastructure in industrial automation within the university and local training/ retraining of engineers with control and automation expertise for local industries are related objectives. As a specific task, an experimental workcell for fish processing is being developed in the laboratory. The theme of the activities of the laboratory is the integration of advanced control, high-level computer vision, and robotic manipulation and devices, for application in the area of fish processing.     

基于PCI1716的CBS系统数据采集与处理方案的设计

针对在利用X射线康普顿背散射(Compton back scattering,CBS)技术进行违禁品成像检测的系统中,在进行实时数据采集的同时完成数据处理与成像显示和刷新容易造成采样数据的丢失和数据错乱的问题,提出了一种Windows系统下基于通用数据采集卡的实时数据采集和处理设计方案.选用某公司的PCL1716高速数据采集卡,配以外部同步信号和简单的脉冲发生模块,在PC机上利用Windows系统的多线程机制,采用可视化编程语言VC++实现数据的连续采集、传输和同步的数据处理与成像显示及存储.实际运行情况表明,该数据采集与处理方案简单实用、开发周期短、成本低、可靠性高.     

Evaluation of operators' performance for automation design in the fully digital control room of nuclear power plants

Recent technical developments in computer hardware and software have meant that human–machine systems can be automated in many respects. If automation fails, however, human operators can have difficulty in recognizing the existence of a problem, identifying what has failed, and taking corrective action to remedy these out‐of‐the‐loop (OOTL) performance problems. Several studies have suggested that taxonomies of levels of automation (LOAs) and types of automation (TOAs) can be used to solve OOTL problems. This study examined the impact of LOAs in process control automation within the context of nuclear power plants (NPPs). A simulation experiment in an NPP is performed to validate this framework using an automatic mode and a semiautomatic mode. Mental demand is found to be significantly reduced under the automatic mode; however, participants felt frustrated with this LOA. Situation awareness is found to be similar in the two modes. The results of an end‐of‐experiment subjective rating reveal that participants were evenly divided between the two modes with respect to generating and selecting functions. It is therefore suggested that human operators be involved in generating and selecting functions under an automatic mode. © 2009 Wiley Periodicals, Inc.     

数字锁相环在电力系统谐波检测中的应用

分析了非同步采样对谐波测量精度的影响,提出采用数字锁相环来同步被测信号的方法。数字锁相环电路采用VHDL语言和可编程逻辑器件设计实现,并用MAX+plusⅡ软件进行仿真。仿真和测试结果表明,所设计的数字锁相环可以很好地跟踪被测信号,如果模值K设为1,当跟踪至180ms时,频率误差仅为0.01Hz。     

基于虚拟仪器的可见光谱数据采集与处理

设计了一个基于虚拟仪器的可见光谱数据采集与处理系统。对彩色线阵TCD2252的RGB三通道输出进行加法处理,提高了系统灵敏度;利用氦灯特征谱线、根据二阶定标法对系统进行波长标定,比传统的线性定标法改善了测量精度;通过网络实时发布测量数据,远程用户可方便地浏览测量情况。利用LabVIEW8.5编写测试程序,实现了光谱的采集、处理、分析、显示及传输等功能。实验结果表明测量误差在可接受的范围内。     

Data semantics for improving retrieval performance of digital newsvideo systems

We propose a novel four-step hybrid approach for retrieval and composition of video newscasts based on information contained in different metadata sets. In the first step, we use conventional retrieval techniques to isolate video segments from the data universe using segment metadata. In the second step, retrieved segments are clustered into potential news items using a dynamic technique sensitive to the information contained in the segments. In the third step, we apply a transitive search technique to increase the recall of the retrieval system. In the final step, we increase recall performance by identifying segments possessing creation-time relationships. A quantitative analysis of the performance of the process on a newscast composition shows an increase in recall by 59 percent over the conventional keyword-based search technique used in the first step     

Overlapping decentralized approach to automation generation control of multi-area power systems

An overlapping decentralized control scheme is presented and applied to automatic generation control (AGC) for multi-area power systems. Based on the inclusion principle, the system is first decomposed in the expanded space as a group of pair-wise subsystems (areas). Then, the decentralized controllers designed, by standard linear quadratic (LQ) control laws are implemented in each pair-wise subsystem. Finally, the overlapping decentralized controller is obtained by coordinating and contracting the pair-wise decentralized controllers from the expanded space to the original space, preserving the inclusion conditions. When applied to AGC of a four-area power system, the proposed methodology not only guarantees AGC qualities, but also increases the system reliability with respect to a wide variety of structured perturbations. Simulation results illustrate the effectiveness of the presented approach both in the general case of information structure constraints and in the cases when some pairs of subsystems are disconnected by unpredicted faults.     

基于LabWindows/CⅥ的傅里叶变换光谱测量的数据采集系统

介绍一种基于LabWindows/CVI的光谱测量数据采集系统,利用LabWindows/CVI的编程优势,提高了编程效率与光谱仪数据分析的处理能力.给出了傅里叶变换光谱测量方法的设计原理、硬件系统构成以及LabWindows/CVI软件数据采集系统,包括实现干涉图数据采集、实时显示、数据分析处理和光谱分辨率的精确计算等功能.实验结果证明该系统满足设计需求.     

Data loss recovery for power failure in flash memory storage systems

Due to the rapid development of flash memory technology, NAND flash has been widely used as a storage device in portable embedded systems, personal computers, and enterprise systems. However, flash memory is prone to performance degradation due to the long latency in flash program operations and flash erasure operations. One common technique for hiding long program latency is to use a temporal buffer to hold write data. Although DRAM is often used to implement the buffer because of its high performance and low bit cost, it is volatile; thus, that the data may be lost on power failure in the storage system. As a solution to this issue, recent operating systems frequently issue flush commands to force storage devices to permanently move data from the buffer into the non-volatile area. However, the excessive use of flush commands may worsen the write performance of the storage systems. In this paper, we propose two data loss recovery techniques that require fewer write operations to flash memory. These techniques remove unnecessary flash writes by storing storage metadata along with user data simultaneously by utilizing the spare area associated with each data page.