Applied Mechanics and Materials Vols. 365-366

Abstract: Acoustic Emission (AE) signal has been used pervasively in the extraction of fault feature and the location of damage. The precision of the extraction and location is determined by the propagation characteristics of AE signal in different structures. In this paper, the propagation characteristics of AE wave in the point contact sphere under continuous and transient AE signal is analyzed; a series of experiments under different condition are conducted; based on wave propagation theory, a simulation model is built using the software of ANSYS LS-DYNA. The results of experiments and simulation models reveal that the propagation characteristics-attenuation, frequency features-of AE signal can be manifested clearly in the experiments and are simulated correctly by the simulation model.

Abstract: Si_1-xGe_x/Si multi-quantum wells (MQWs) film is excellent bolometer materials, which issensitive to radiation in the 8-14 micrometer wavelength region. As an important property,temperature coefficient of resistance (TCR) reflects the quality of infrared focal plane arrays.This paper designs a MQWs temperature and resistance data automatic measurement system basedon LABVIEW, and unifies data results, the characteristics of MQWs film was analyzed anddiscussed. The task is to examine the TCR for different material-compositions of MQWs.

Abstract: The animal experimental is a fundamental equipment for biomechanics experimental, which attached to electric shock instrument, oxygen analyser or high speed recording system. The animal experimental has an advantage that it offers a single environment excluded the interfere from natural regimes. In this paper, a small animal observation experimental-bed was developed based on C++. The interface of control program was developed using Visual Basic 6.0 and the COM port communication between SCM LM3S8962 and PC was developed based on C++ Builder 6.0. The velocities of belt of the small animal experimental can run according to line, sinusoidal curves, triangular wave curves and square wave curves. Moreover, the control program provides a combined velocity based on above curves for satisfy the sophisticated experiment of locomotory small animals.

Abstract: This paper introduced four common test methods of acoustic contribution of body panels. The methods using PU sensor to array measure vibration velocity of body panels. Then, the vibration velocity of body panel multiplied by the area of panel to get the value of sound source intensity. Use reciprocity method to measure acoustic transfer function. In the experiment, the vector sum of the product of sound-source intensity and acoustic transfer function is used to compose the sound pressure contribution of the panels. The experiment proves that the composite value of acoustic pressure spectrum of drivers right ear coincide with the measured value. Therefore, this method is proved to be valid.

Abstract: ATOS three-dimensional optical scanner is one of the most advanced technologically three-dimensional optical scanning devices. It can automatically put together the multiple scan view image by the reference point of the measurement system, with high accuracy, high speed Etc. It is widely used in automobiles. The paper combines with the experience in vehicle measurements, analysis the error cause in the actual use, points out ways to reduce or eliminate error. It has the great application value to actual measurement.

Abstract: Demand for high-speed fiber optic gyroscope data acquisition and real-time record, the design of the SD Card as storage medium to large capacity fiber optic gyro high - speed real - time acquisition and bulk storage systems, The system by applying the sd2.0 protocol and fat32 file systems in the system, enable real - time Data Acquisition of fiber optic gyro and large capacity storage. Experiments have shown that the system properly designed, easy to use, high reliability to meet the actual demand, is of important practical significance.

Abstract: According to lower efficiency, non-uniform distribution and metering difficulty in grouting, this paper describes the development of monitor system for automatic grouting of metamorphic concrete. Based on PLC and HMI, it uses the knowledge of signal acquisition and hydraulic control technology. This system calculates the rotation division angle to measure the amount of grouting through the hall-switch installed on the rotor of slurry pump. The PLC will realize signal acquisition, slurry metering, and effectively control of the slurry pump by solenoid valves and hydraulic motor. In addition, the HMI provides the functions such as parameters setting, operation controlling and data displaying.

Abstract: According to the perspective projection performed by a pinhole camera, taking full account of the lens radial distortion factor, the transformation between the camera coordinate has been analyzed. Combining with camera model instance of surface mount devices, the system uses Halcon machine vision software which has a powerful geometric and image computing functions to solve the camera calibration parameters and the accuracy of calibration results has been verified in practical applications. This method has advantages of computational efficiency and good value of cross-platform porting applications.

Abstract: In this contribution is presented the method of choice of the right sensor. The selection of appropriate sensory equipment means a completion of requirements. Unfortunately, very often these requirements are not exactly known or detail. The first issue of designer is to get the most information about future applications of measuring device, all appropriate conditions of operations, etc. The short list of requirements should be the most detailed.

Abstract: Time synchronization is a new hotspot in the research of wireless sensor network technology (WSN). Even though many applications of WSN require the clock of sensor nodes to keep synchronization, the traditional time synchronization algorithms are not suitable for WSN because of the characteristics of WSNit has special requirements in synchronous scope, energy consumption and synchronization precision. For this paper the Routing Integrated Time Synchronization (RITS) algorithm was analyzed. Furthermore, by averaging the multiple sets of data received by the target node and constructing a best fit straight line with the multiple received pairs, the RITS algorithm is being improved. Analysis showed that: improved algorithm inherited the advantages of the original RITS algorithm and improved the time synchronization precision to a certain extent.