Advanced Materials Research Vols. 889-890

Abstract: When detecting torque with surface acoustic wave (SAW) resonator sensors, the real strain of the host structure is not exactly consistent with the strain of SAW resonator due to material mismatch and the finite-thickness adhesive problem. A 3-layer (host structure, adhesive, and resonator layer) model is established. Finite-element Analysis (FEA) was used to investigate the strain transfer from the metal substrate to the SAW resonator (SAWR) through a bonding layer. The results show that the values of the strain transfer rate of FEA agree well with the experimental data. It can be concluded that FEA is of great value for SAW sensor design and sensing applications.

Abstract: Due to the complex structure of nuclear facilities in a high irradiation environment, people were hard to approach it, In view of these situation a fault diagnosis method based on HMM(Hidden Markov Model) of capturing the audio signal while facilities were operating was proposed. With the strong modeling ability, HMM could be applied to analyzing such as audio signal non-stationary time signal. By using this method, the original mechanical structures of nuclear facilities were not destroyed. The preposed sensors were needed as few as possible by the whole diagnosis system and which had a simple structure, low cost structure, the fault diagnosis rate was high and so on. State monitoring and fault diagnosis system of complex nuclear ower equipment could timely and effective to provide running status and potential failure information for operating personnel, which had a vital significance for the safe and reliable operation of nuclear power equipment.

Abstract: In order to improve the performance of sensor, Using ANSYS software, the three-dimensional finite element modelling method and simulation results of micromachined airflow omnibearing level posture sensor are presented. The results show that: (1)Using the sense organ’s symmetry characteristic, a half model is built first, which is convenient for modelling and observing the simulation results;(2) Gridding should be meshed more densely where fluid grads is large, which is helpful of saving simulation time and improving precision. Compared to two-dimensional modeling, the simulation results of three-dimensional modeling are more comprehensive and exact, which provides dependable basis for further research of the sensor.

Abstract: The sensitive mechanism of micro airstream gyroscope was explained by calculating the distributing of stream field in the sense organ. According to the real size of micro airstream gyro-scope, ANSYS-FLOTRAN CFD was used to create models and work out the gas flow field and distributing in the two-dimensional chamber with different angular velocities. The results show that while the gyroscope in a static state the gas velocities at both hot-wires are equal as well as the current, and the output voltage is zero. On inputting an angular rate the gas velocities differ and a voltage signal proportional to the input angular rate is achieved.

Abstract: As a key factor in a testing system, sensor nonlinearity has always been the study focus in the field of engineering and techniques. In order to accurately reflect the practical characteristics of a fiber-optic micro-bend sensor, Levenberg-Marguardt (LM) algorithm is used to optimize the correction of the weight values of standard back propagation neural network (BPNN). The learning process of improved BPNN based on LM algorithm (LM-BPNN) is also illustrated mathematically, and LM-BPNN is applied in fitting the input and output characteristic curve of a fiber-optic micro-bend sensor. The simulation results show that LM-BPNN is superior both in its convergence rate and fitting precision over standard BPNN.

Abstract: Based on the Bluetooth technology, using wireless sensor network design the mountain of debris flow health monitoring system, analysied and fixed mountain monitoring elements, given the data acquisition and processing methods, the project is simple, low cost, high reliability . To solve monitoring, early warning, data analysis of the current landslides and debris flow disaster, which are very practical.

Abstract: In the field of aerospace, the Gardon heat flux sensor is not allowed water-cooling device, so the sensor sensitivity would be greatly affected by the temperature rise of the heat sink. To deal with this problem, a high-temperature, high-precision heat flux sensor is designed based on the metal thermo-electric effect and the principle of thermal conduction. First of all, the measuring principle of the Gardon heat flux sensor is expounded. Then the heating process of the copper heat sink is derived. In order to slowdown the temperature of the heat sink, kinds of adiabatic measures are taken. Thermodynamic simulation for the designed sensor is performed by the ANSYS finite element simulation software. Finally, experiments have been carried out to test the performance of the sensor. The experimental results show that the sensitivity of the sensor with adiabatic measures did not decline within 1000s, and its linearity is 1.38%. So the sensor is able to meet applications in the aerospace field.

Abstract: Modeling technology and simulation for micro-mechanical gas-flow level-gesture sensor is explained. Through ANSYS-FLOTRAN CFD program and by means of a series of procedures, such as 3d-modeling, network modifying, loads applying and equation solving, FEM analysis has been obtained. In order to analyze more conveniently and feasibly, By setting up several rational mechanics model schemes and using the method of cutting partial volume modeling, it has saved the massive time and the energy; The skills such as meshed times without number and the key-line meshed in even advanced the veracity and the calculation progress of simulation results.3d-modeling provides a more effective road for optimization of gas-flow level-gesture sensor.

Abstract: In order to improve the efficiency of water pollution source online monitoring instrument under remote metrology and reduce the intensity of labor operation. 3G technology has been used to connect the instrument with the client's network through the STM32 microprocessor and A/D conversion. Current A/D conversion and 3G module have been used to complete the testing data transmission. In order to get the data, the software of server and client has been programed. Field experiments show that the system is stable and reliable, which can effectively meet the demand of the measurement.

Abstract: Along with the continuous development of embedded systems, embedded products take higher requirements on the scale and performance of system software, and contributing to the complexity of control algorithm. So it would take more time and expense to realize the control algorithm. Therefore, traditional design is out of date and cant cope with the modern development rhythm well. While the Model-Based Design, is an efficient design method to deal with complex embedded control systems. It provides a common development and test platform for the engineers. In this paper, we take the power windows control system as example; establish the algorithm model with the Simulink/Stateflow. Then we introduce these process of the control system design which is based on the Model-Based Design method, according to the result of the final experiment, we prove the efficiency of this method, providing a reference for the design of other complex control systems.