Applied Mechanics and Materials Vols. 333-335

Abstract: In the process of the Hilbert-Huang Transformation, empirical mode decomposition (EMD) and Hilbert Transformation of the IMF components may result in the terminal effect, utilizing the support vector machine (SVM) extend the signal sequence and IMF components to weaken the end effect. The paper analyzes the fault signal which extracted under the different fault conditions to complete the fault location. The simulation result shows that using SVM can effectively restrain terminal effect; In the different fault states can have a high positioning accuracy.

Abstract: With the difficulty to detect and locate the hidden insects, microwave Doppler theory has been used to solve this problem. In this paper, we establish a microwave reflection model using the insects body as the reflector. According to the three different movement patterns of the experimental insects, we implement the MATALAB simulation.By analyzing the reflected signal using the time-frequency analysis, we can easily distinguish the movement patterns of the insects with high sensitivity. The hidden insects can be efficiently detected without any harm. It has great significance to the further development of the hidden insect detection technology.

Abstract: Due to the feature and the forms of motion of the gears, the vibration signal of the gear is mainly the frequency modulation, amplitude modulation, or hybrid modulation signal corresponding to the gear-mesh frequency and its double frequency signal. When faults arise on the gears, the number and shape of the modulation sideband will be changed. The structures and forms of the FM composition differ according to the type of faults. According to the above mentioned characteristic, this essay raises a method to disassemble the gear vibrate signal, points out the formulas to build up characteristic vector, on that basis, the essay raised a gear fault diagnosis method based on EMD and Hidden Markov Model (HMM), this method can identify the working condition of the normal gears, snaggletooth gears, and pitting gears.

Abstract: Firstly, basing statistical results pavement quality indicator (PQI) calibration value of asphalt pavement with different aggregate types and nominal maximum aggregate sizes, the importance degree of the influence of the two factors on PQI calibration value was obtained by using the statistical software of SPSS. Then, PQI was used to detect the compaction of asphalt pavement and the detecting results of loose laying density, loose laying thickness and compaction density of asphalt mixture were used to calculate the thickness of asphalt pavement. All results above were compared and analyzed with the detect results of cores. Finally, the construction quality process control method of asphalt pavement was described. Results show that the aggregate type and material quality is the important factor to the PQI calibration value; the density of asphalt pavement detected by PQI and the thickness calculated have fine correlation with the detecting results of cores, those detecting results are dependable; The construction quality instant control of asphalt pavement could be achieved by detecting the loose laying density and thickness of asphalt mixtures.

Abstract: The equipment resource planning is considered during the procedure of job schedules in manufacturing enterprises. Based on the analysis of interaction between production task and equipment status, a task driven equipment status monitoring system is presented. Through the development of an analyzer, the system can regulate the equipment status automatically according to the perform stage of production tasks and provide the adequate equipment information for job schedules. Finally, the application examples are introduced and the characteristics of the system are summarized as well.

Abstract: In order to satisfy the test demand of Electric Vehicle batteries, after the analysis of the existing battery test systems, aiming at the problems of them, an EV battery test platform with high degree of simulation is designed, based on the upper and lower computer structure. The PC software is compiled, which could control the battery to discharge with constant current or constant power, or to simulate the real road status, by the communication with the lower computer through CAN bus and 485 bus. The corresponding control method to realize the discharging test with constant current is designed, also an interface to Excel which can read the configure information from Excel to realize the simulation of discharging test is designed. Several battery packs test are completed.

Abstract: The rapidly increasing usage of high-powered devices and the high specification in personal and industrial/medical devices has led to a greater demand for a SMPS for high-powered devices. A stable and reliable power source for such devices and research on power quality monitoring systems are needed. To these ends, this paper introduces a SMPS monitoring system based on ZigBee communication. The SMPS monitoring system uses ZigBee to collect the voltage, current, and temperature data from SPMS in real time. The collected data are visually synchronized and the current power supply status is displayed to the operator. In addition, to prevent any decline in the quality of the power, the system gives feedback via smartphone to the operator if errors are detected.

Abstract: A method based on OEMD (Orthogonal Empirical Mode Decomposition) and the theory of time-frequency entropy was applied to detect different rail fastener conditions. The original vertical vibration acceleration response of rail under different fastening conditions was obtained from outdoor experiment. The OEMD method was used to get orthogonal IMFs (Intrinsic Mode Functions) of the original vibration signal. The Hilbert time-frequency spectrum was then obtained based on the orthogonal IMFs and corresponding entropy was calculated and compared. The results show that the method is available to detect different rail fastener conditions.

Abstract: Electromagnetic ultrasonic nondestructive testing technology, which it have the advantages of withstand high temperature and without coupling agent,is widely used in Nondestructive Testing (NDT) field. To effectively detect the defects, the dispersion characteristics and multimode of guided waves in the plate are studied by the disperse simulation software, and the variation of dispersion curve is analyzed by the geometric parameters and materials of plate. The results showed that the dispersion characteristics of guided wave in the plate is depended on the thickness and material of plate, and dispersion and the multimode characteristics of plate are better at low frequencies and smaller thickness. This is helpful to selection of Electromagnetic acoustic transducer (EMAT) parameter and detection operating point of guided wave.

Abstract: Based on analysis of the ETM+ and TM remote sensing images of LandSAT satellites, the stability and evolution characteristics of the nearshore coral reefs at Changjiang, China was investigated. The results showed that the maximum distance from the outside edge of the coral reefs to the shoreline is 1.1km, and the corresponding minimum distance is 200m. From 1973 to 2013, the locations of coral reef chain are relatively stable with maximum variation 50m. Generally, the natural tidal currents and waves can not destroy the coral reefs, and the human activities do not change the biological environment of the coastal area. Therefore, the Changjiang coral reefs could keep stable in the long term.