Research On SHM System Based On Wireless Sensor And Virtual Instrument Technology

Some advanced technologies for structural health monitoring (SHM) have been caused much more attentions, in which the wireless sensor and virtual instrument (VI), which have been enabled by the convergence of Micro Electro Mechanical Systems (MEMS), wireless communication, instrument and computer technology, is recently received special interests. The wireless sensor node and base station are designed and constructed. The design and implementation of a monitoring and evaluating soft system based on virtual instrument (VI) techniques is discussed and tested in the laboratory. The main contents are listed as follows:1. Considering the disadvantage of the traditional SHM system, a new SHM system based on wireless sensor and virtual instrument is discussed and proposed.2. Considering only the signal of acceleration, stress and temperature and humidity could be sensed by currently wireless sensors, and the highest sampling frequency just can reach 1kHz, a novel structure and design practice for ultrasonic stress waves reception of wireless sensor is proposed. A wireless sensor node of minute extension and low power consumption and a base station are designed and developed.3. Considering the communication, data processing and coordination problems of wireless sensor, software of wireless sensor is designed and developed based on ZigBee protocol. The performance of the wireless sensor is investigated through test in the laboratory. Sampling frequency reach to 50kHz, data precision reach to 10bit.4. Considering the implement of SHM system is long-period, high-cost and unflexible, a software system of monitoring and evaluating based on VI is designed and developed. The system is composed by several function modules, including data acquisition, data communication, signal analysis, sound alarm, etc.5. The SHM system is tested in the laboratory. Several methods of signal processing, including wavelet analysis, are utilized for the proper system, in order to gain the character and eigenvalue of the signal. The damage location in plant based on acoustic emission (AE) technology is first realized by LabVIEW. It is proved that the system possesses strong conveniently and more precisely in practical use.