Applied Mechanics and Materials Vols. 239-240

Abstract: A data acquisition system for electronic automatic transmission test, which makes use of American NI’s data acquisition card, is designed based on Virtual Instrument. The data can be collected by the data acquisition system include automatic transmission oil pressure, solenoid duty, as well as speed of turbine and output shaft of transmission and throttle degree of engine and so on. The key problems of the system design are measurement method of automatic transmission solenoid duty, signal conditioning circuit design and how to improve sampling rate of the system. Test platform is of a armored vehicle which has equipped a high-power electronic automatic transmission. The automatic transmission shift control strategy and characteristics of throttle oil pressure etc can be obtained through test data acquisition.

Abstract: To resolve the problem of acquiring multi sensors signals synchronously in a distributed system, a project of distributed synchronous data acquisition based network time server was designed. The system comprised multi distributed sensor units, a centralized control unit and D&C (display and control) center. Each sensor unit was equipped with a data acquisition module. All data from sensor units were concentrated and sent to the D&C center, and the D&C center implemented power supply and management of sensor units via the centralized control unit. To synchronize the data acquisition modules, a network time server was employed in the D&C center. It received standard time information from GPS and outputted the time signal with DCF77-encoding. Each data acquisition module received and decoded DCF77 time signal, obtaining absolute time and synchronizing its time base. Above project was applied successfully in a system comprising 20 distributed sensor units. The results prove the designs feasible.

Abstract: Datacenter is the important infrastructure to provide resource and service in Internet. Due to the widely observed congestion, all kinds of transmission control mechanisms have been proposed to satisfy diverse network performance demands. Based on InfiniBand (IB) which is widely applied for datacenter construction, this paper proposed a generic testing and evaluation platform IBperf to verify transmission control protocols. We designed a central controller to instruct distributed clients to generate different communication patterns and execute commands of the protocol. The transmission performance can be derived based on the captured packets and digest. In the experiment, IB congestion control (CC) was evaluated through IBperf on our real IB platform. IBperf showed the improvement of fairness and throughput with low overhead based on CC mechanism. It proved IBperf to be an effective tool for the evaluation of IB datacenter.

Abstract: This paper introduces an electric quantity data acquisition system based on WSN, and a special algorithm which is used in multi-channel electric data acquisition is also introduced. In this algorithm, a large number of hardware circuits are replaced by software functions, the design of the hardware is simplified, and it is of practical value. The system includes pulse kilowatt-hour meters, Data Acquisition(DAQ), data concentrators , Server and Zigbee network nodes (Router and Coordinator) and so on. This paper explains the structure of Zigbee network, the network features of DRF1605H Zigbee module, the special algorithm of electric quantity data acquisition, the structure of WSN electric quantity data acquisition system, the design of electric quantity data acquisition hardware and software and so on. After designing and implementing this system, the electric quantity data acquisition, the data transmission between each ZigBee node and the ability of anti-interference are tested. The results of each test show that each part of the system works properly and meets the original requirements of the design. From the running condition of the system, the system for electric quantity data acquisition and transmission has some characteristics such as a simple structure, accurate data, a strong anti-interference ability, high reliability of WSN, easy maintenance, good scalability and so on, which indicate it has a promising application future. This system helps to plan the use of electricity and dispatch the power. Not only is the electric energy management automation level improved, but also manpower and material resources are saved, leading to remarkable economical benefits.

Abstract: Data acquisition system of the flash-butt welding machine had been designed for sampling current and voltage data during welding process. Software, which could sample and analyze the welding data easily, has been developed based on LabVIEW and Visual Basic. The acquisition system could sample, store and query the welding current and voltage data, as well as display the real-time waveform of them. By analyzing welding data and waveforms, we could extract characteristic signals over all phases, including flash stability, input heat and plus-minus symmetry of current waveform. Further more, he characteristic signals’ extracting and current waveform’s analyzing, could be used to instruct the welding processing debugging and the diagnosis of equipment failures, especially the failures which was difficulty to be found with conventional methods.

Abstract: Due to the rapid development of manufacturing technology, high-speed high-resolution data acquisition system has been widely applied in plenty of engineering fields, such as radar, environmental surveillance, mass spectrometry, etc. In order to satisfy the increasing requirement, we present the design of a high-speed data acquisition system, which is mainly composed of high-speed time-interleaved analog-to-digital converter, high data throughput interface based on 10 gigabit Ethernet. The detailed design and realization of each module are presented. Finally we test and analysis the performance of the ion signal acquisition system, and the results show that the system performs fine speed, high precision and stability.

Abstract: Electric Energy Data Acquisition System (EEDAS) is not only the critical basic system of the intelligent electric consumption service area, but an important part of building a unified and intelligent grid. Its technical advancement will directly relate to the energy efficiency and cost effectiveness of smart grid. This paper introduces the framework and functions of EEDAS, presents the differences between EEDAS and AMI, analyzes the current situation and obtained effectiveness in State Grid Company of China and prospects the development trend of EEDAS in the future.

Abstract: A design method of data acquisition and data storage buffer control logic in the quadrupole mass spectrometry was proposed. The control logic builds a high-speed built-in FIFO memory on FPGA to buffer of mass spectrometry data. FIFO storage capacity of 16K bytes and simultaneous reading and writing speed of 60Mbps were realized by control logic system. The data acquisition and storage buffer system had been used on the Quadrupole Mass Spectrometry and Quadrupole Ion Trap Mass Spectrometry to reduce the single scanning time of MS analysis. A higher sensitivity had been obtained by increasing the scanning rate of mass spectrometer.

Abstract: The features of wavelet transform is firstly introduced in this paper, then the directional wavelet is introduced to pick up image characteristic, finally, the experimental results of directional wavelet used in characteristic identification of character-figure is given, it proves this characteristics puck-up method has good local direction characteristics, this function make it has good identification capacity for typical noise of character: stroke missed, stroke break, mechanism twitter, stroke conglutination, so it very useful for character identification.

Abstract: An improved codeword construction method was used to encode the BCH code and LDPC code in this paper according to the latest standard defined by digital video broadcasting standard(DVB), and moreover the data overflow problem was solved. The LDPC code was decoded by the reduced complexity Min-Sum decoding algorithm, in which the coefficient was studied. Fixed-point representation and decoder quantization were proposed and simulation results show that 6-bits and 16-bits uniform quantization can make close to the performance of unquantized decoder, which reduces the decoder complexity for hardware implementation.