Research On Key Technologies Of Smart Wireless Sensor Network For Structural Monitoring

With rapid deployment, self-organized into networks and distributed collaborative information processing capabilities, wireless sensor network technology can effectively solve the inherent defects of the existing structural health monitoring and structural strength test system and meet their more efficient, high-performance monitoring requirements. Much progress has been made in wireless sensor network research for structural monitoring, but mostly for the civil engineering structures. The aviation structure monitoring application research based wireless sensor network is the initiation of the exploration stage. However, using the technology on large practical structures, many problems must be solved in practice efficiently. There is no dedicated wireless sensor network node and platform for the structural monitoring applications. Since density and different kinds of sensors have to be adopted for the monitoring of large scale engineering structures, there are some key issue including effective wireless sensor network architecture, collaborative network management methods and synchronization networking mechanisms. To large-scale structure monitoring, in this dissertation wireless sensor network application technologies and implementation methods are researched especially for aerospace structures. Main contents as follows:With high precision, large measuring range and integration requirements, the wireless strain sensor node is designed by the modular design method. Resistance strain guages can be directly connected with the wireless strain nodes. Then the power, distance and anti-interference performances of the node are tested respectively.For active structural health monitoring applications, a high-speed wireless piezoelectric sensor network node is designed. The PZT node includes active excitation module, data acquisition and processing, wireless communication and power module. The test results demonstrate that the high-speed wireless PZT sensor node can complete active excitation, sampling and processing of the response signal for the application of active structure monitoring with integrated software and hardware.The wireless sensor network architecture is designed for structural monitoring applications. Using network calculus theory, a star-cluster wireless sensor network architecture-analysis model is made and validated with IEEE802.15.4 communication standards for the fuction in the analysis of network performance metrics such as network delay and bandwidth efficiency.The wireless base station node is designed and includes integrated MCU module, wireless transceiver module and USB2.0/UART conversion module. The communication performance comparison test is completed with the MicaZ node.For the star-cluster based network architecture, a clock synchronization method is proposed. The simulation results show the feasibility of the synchronization method. A multi-task allocation strategy is proposed based on the genetic algorithm optimization. The remainder of this section presents a multi-agent design method and system evaluation for wireless sensor network based structural health monitoring to validate the efficiency of the multi-agent technology.The synchronized data collection method based the equal time intervals is proposed and tested with the designed sensor nodes in TinyOS. For structural monitoring applications, a wireless sensor network monitoring management software is designed.To verify the functionality of the designed wireless sensor network for SHM and strength testing capability, the validation systems are developed on the actual big CFRP wainscot, reinforced aluminum structure and the real aircraft undercarriage.