Applied Mechanics and Materials Vols. 556-562

Abstract: This paper proposed a novel multimedia player based on embedded system. Different from normal player, it decodes the audio-video stream using a multithreaded mechanism based timeline, and does not need the traditional driving library for playing media — FFMPEG. The player decides the IDR frame for every group of audio-video stream at first, then plays stream according to the interactive model of audio and video. It makes the best use of decoding acceleration engine of embedded chip, has higher decoding efficiency, and saves a lot of resource for embedded system.

Abstract: A high-speed 64b/66b decoder for SerDes system was designed in TSMC 0.18-μm CMOS Technology. The chip is composed of Block Sync, Descrambler, Decode Process and Receive Control. To make the system can be work in high speed, we use a lot of technology such as pipeline strategy, optimization of complicated logics and parallel descrambler.

Abstract: Micro Multi-propeller Multifunction Aerial Robot (MMAR) needs a low-cost, small-size, low-power and lightweight navigation system. To meet these requirements, a compact navigation system for micro MMARs is designed and implemented. The system consists of a GPS receiver, a MEMS inertial measurement unit (IMU), a barometer, a magnetometer and a dual microprocessors navigation processing platform. According to the characteristics of the sensors used, the optimized Kalman Filter (KF) is designed to implement the navigation data fusion with less computational cost. The test results show that the system’s small size, low power consumption, light weight and better dynamic accuracy can meet the requirements of micro MMAR autonomous flight.

Abstract: Although there are many studies on application of FACTS unit, especially application of reactive power generating unit for power system to enhance voltage stability amplitude and transient stability as considered, the evaluation and selection of suitable power generating unit (STATCOM or SVC) as well as optimal compensation size in the analysis of steady and transient state is not paid attention to. This article studies the above described issues to give a solution to install reasonable reactive power generating source (kind of Var source, location, size) for the power system. The analysis will be based on the technical factors rather than economic ones. 500kV grid system in Vietnam will be used in the calculation until 2015. To deeply evaluate, the implementation plan of reactive power compensation was only studied for 500kV grid in the South, where the load demand is large and can be dramatically increased. The results of power flow calculation, the analysis of characteristics of PV, OPF, and transient stability were studied through PSS/E-30 software.

Abstract: The design and realization of a wideband variable gain amplifier for RF system is presented. The cascade of LNA and controllable attenuation makes the design have a 0-90dB gain adjustment range. Special care is devoted to the solution of typical problems encountered in the design of the amplifier, such as signal shielding and power supply decoupling. The amplifier uses passive amplitude-frequency equalization, 0.1-460MHz band variation is less than 1dB, the 3dB bandwidth is up to 520MHz. The noise characteristic is low, the total input referred noise is less than 15.5nV⁄√¯Hz.

Abstract: According to the current energy trends, the paper designs a power supply device to keep the Power Supply Platform that the solar power as the main energy, meanwhile the Storage Battery and alternating current as the minor energy working normally. The device has the function of switching the power supply to achieve the uninterrupted power supply to loading in any environment so that will output DC stably and carry three charging to the Storage battery. Through the Ps-pice software simulation results show that the modules can meet the design requirements. It can achieve the results of switching power and select function of the Storage battery power charging module through controlling circuit by Proteus simulation software. The power supply device has the advantages of high reliability.

Abstract: According to the growing need for renewable energy. Grid-connected photovoltaic system is used in many territories. To suppress the high-frequency harmonics of high power photovoltaic inverter, a LC low pass filter (LPF) has been proposed in this paper. The following have been done in the study: analysis of the high power photovoltaic inverter system and its harmonics, method of high-frequency harmonics suppression, and simulation of high-frequency harmonics suppression. According to the normalization method, the parameters of LPF are calculated. Then the parameters are put into a simulation model. The simulation result show that THD is 7.26%. It is much less than the former 78.19%. So it can be widely used in power system to suppress the high-frequency and to ensure the quality of electric energy.

Abstract: This document improved genetic algorithm and Intelligent discern points algorithmin chip placement and routing for Board-level photoelectric interconnection, by comparisonofthe algorithm results to verify the effectiveness and practicality of the improved algorithm. First introduced the features of chip placement and routing for Board-level Photoelectric Interconnection. Then describes the improved method of genetic algorithms and intelligent discern points algorithms. Finally, implement algorithm by C language on VC6.0++ platform, while the data import MATLAB to displays the optimal placement and routing results. The results show that the effectiveness of improved algorithm, which has a guiding significance for the chip placement and routing.

Abstract: The direct digital frequency synthesis (DDS) technology has high frequency resolution, fast frequency switching, low phase noise and higher frequency stability, so it is widely used in communications, aerospace, instrumentation and other fields. In this paper, the DDS system was designed based on Field Programmable Gate Array (FPGA) and hardware design language (VHDL). The experimental and simulation results show that the system has stable output frequency, high frequency accuracy, adjustable frequency and phase.

Abstract: With the promotion of our country policy about electric vehicles, the development conditions of electric vehicles are improving day by day. However, the application of large-scale electric vehicles will have a direct impact on the power grid. Guilin is taken as an example to analysis the impact of models including uncontrolled charging, controlled charging and controlled charging/discharging model in different scales on the power grid using the Monte Carlo algorithm. The simulation results show that the proper number of electric vehicles involved in the controlled charging/discharging model can effectively achieve the target of peak clipping and valley filling. However, after more than a certain number, it will bring new pressure to the power grid.