Advanced Materials Research Vols. 139-141

Abstract: An embedded greenhouse monitoring & control system based on wireless sensor networks(WSN) was presented, in order to solve problems in traditional systems, such as high maintenance cost and low mobility, etc. The paper introduced the overall structure of system, and then designed the hardware architectures of core-node and sub-nodes. After that, the flow chart of nodes was programmed, based on proposing a suitable protocol of wireless communications. The life of nodes was extended obviously by adopting the sleep-wake mode.

Abstract: After analysis of the TOSHIBA Corporation's Linear CCD TCD1501D drive timing, making full use of the relationship between this chip 6 phase driving pulses. Based on Verilog language, this paper describes in detail the three kinds of different frequency CCD-driver and the circuit which can switch freely between the different driving frequencies. ALTERA Corporation's Cyclone II series FPGA chip is chose as the linear CCD driving frequency regulator. The function simulation and the timing simulation of this system is successfully achieved with the Quartus II 9.1 and ModelSim software, then the system is debugged on Amy's EP2C8Q208 FPGA / NIOS development board, the result of debugging shows CCD drive frequency adjustment system suitable the design of freely switch of the CCD different driving frequency. Experimental results show that the system can perfect drive CCD device work

Abstract: An analytical model of an eddy current sensor designed for noncontact distance measurement is presented. The device consists of two planar coil (driver coil and pickup coil) stacked on the magnetic core. The planar coil fabricated by UV-LIGA technology with SU-8 photoresist is illustrated, and the permalloy magnetic core electroforming process is presented also. Tested with 10-50 KHz sine signal, the output voltage of the sensing coil reached 30mv with a Ni target placed at a distance of 20μm. And the experimental showed a linear relation between the distance and output voltage within 60μm distance. The amplitude trend increases with the increasing of the frequency and amplitude of excited signal, which is according with the theory analytics. The whole size of the device is: Φ5mm×1.5mm. The results demonstrated that the device could nondestructive evaluate the distance and be easily integrated on chip, and the UV-LIGA Process could be used as a new method to fabricate the micro eddy current sensor massly.

Abstract: The pattern of using the household billing to promote heating energy savings has become a focus discussion in the current national energy conservation. However, based on the fact that there is so much impurities in domestic heating system pipes, the research work of the flow meter adapting to our nation has been carried out slowly. In this paper, we report a research of a V-type installation flow meter. The meter uses the through V-type arrangement ultrasonic sensor- pair. It measures the flow by the time difference method and the entrance and exit temperature of the unit by platinum resistance-pair temperature sensors. It calculates the heat consumption by k coefficient method. The flow meter has been carried on the online testing in a district of Beijing in 2009.

Abstract: Cylinder with multiple diagonal slits is one of the core parts of longitudinal-torsional resonance ultrasonic device. Its structure was more complex, the traditional processing processed it very difficult, and the traditional analytical methods were also difficult to make accurate description to system. The paper researched cylinder with multiple diagonal slits using experimental method, analysis of electrical discharge machining forming tools of the slits and three-dimensional modeling; developed cylinder with multiple diagonal slits, analyzed longitudinal-torsional resonance and mechanical properties of cylinder with multiple diagonal slits using finite element analysis method. Tested resonant frequency of cylinder with multiple diagonal slits with precision impedance analyzer. The finite element analysis results compared with tested results, and analysis of error between them, finite element analysis results slightly lower than the test results but the error was within the allowed range. Comparison of results and analysis of error indicated that developed cylinder with multiple diagonal slits meet requirement.

Abstract: With the development of underground rail, the problem that vehicle vibration affects the vehicle’s life-span and harms the health of the passenger has been concerned. In this paper, a vibration test system has been formed with data collecting instrument and acceleration sensors to collect the signals of the metro vehicle floor when it running at the ATO (Auto Train Operation) mode in the tunnel, Analyzing the regulation of vehicle vibration signal change that come with the change of the route condition, such as curve, slope, and so on. Obtain the relationship between the road condition and vehicle vibration. The analysis result shows that, the vehicle vibration not only be affected by the structure of the vehicle itself and the geological condition on which the track laid, but also has close relationship with the route condition.

Abstract: In order to realize the DSP Video Image Processing System works well in the highlight environment, the system control software is designed. In this control part, the ultra-low power MSP430 single chip microcomputer (MCU) is the core, which can be programmed to control the DSP Video Image Processing System, the video A/D converter and the highlight protection circuit by the Inter-Integrated Circuit (I2C) bus. The Image Processing algorithm models can be selected. Whether the highlight protection circuit is turned on or not depends on the comparison result of the environment light and the MCU light threshold. The control program code has been debugged and tested through the MSP development board and the IAR C-SPY debugger. The result shows the DSP Video Image Processing System Control Software is ideal.

Abstract: The undamping differential vibration equation of a six-axis accelerometer was derived based on the Lagrange equation. The theory of matrix iteration was introduced to solve the inherent frequencies and corresponding mode shapes of the six-axis accelerometer, and the theory can also avoid solving high-order differential equation which will happen in the traditional theories. The steps of matrix iteration were described in detail. It was found that every element of the system inertial matrix and stiff matrix is the function of the structure parameters in the calculation. For expanding the measuring range of the accelerometer and increasing the basic frequency, the relationship figures between the basic frequency and the structure parameters of the accelerometer were plotted by means of programming, which supplies the theoretical basis for the structure parameter optimization design of a six-axis accelerometer.

Abstract: Vibration localization of bladed disk turns to be much complex when a number of blades are assembled into periodic groups. This work focused on natural frequency distribution and modal localization of bladed disks with grouped blades based on the lumped parameter models, and effects of the blade number in each group on natural frequency were studied. Then Monte Carlo method was applied to analyze the sensitivity of modal localization to the random mistuning of blade stiffness. The results show that the number of blades in each group influences the nature frequency of bladed disk with grouped blades, and modal localization of tuned bladed disk with grouped blades is found in the closely spaced modal region. Moreover, compared to the bladed disk with free blades, the modal localization of bladed disk with grouped blades is much less sensitive to random mistuning of blade stiffness.

Abstract: Asymmetric dynamic propagation of mode III: crack under variable moving loads on the crack surface is investigated using the theory of complex functions. Using the approach of self-similar function, the problems are readily transformed into Riemann-Hilbert problems. The paper presents a new mechanical model for dynamic crack propagation, in which the crack is under the conditions that the variable concentrated loads Pt3/x2 and Pt/x move along x-axial with velocity β. And then, analytical solutions of stress, displacement and stress intensity factors are attained, respectively. These solutions are utilizable to attain solutions of arbitrarily complex problems, using the superposition theorem