关键词: 多传感信息, 扩频, 应力波通信, 结构健康监测

Abstract: In order to meet the requirements of multi-sensor communication for structural health monitoring in spe-cial environments，a new communication method using multi-sensing stress wave，which is on the basis of spread spectrum，is proposed． In this method，stress wave is utilized as a message carrier，all sensor data in the same area are grouped into some sets of dual-channel signals according to their importance，m sequence code is used as a spread spectrum code to broaden the baseband spectrum for distinguishing signals between two different groups，and Walsh code is used as an address code to distinguish different sensors in the same group． Moreover，the change of carrier's relative phase between neighboring symbols is utilized to modulate transporting information，and the received signal is synchronized before the synchronous demodulation of the carrier． Then，the correlation disprea-ding of demodulated signal is executed by the pseudo-noise code of each sensor group． Finally，the original binary signal is recovered after the judgment of each channel to gain the corresponding sensor data． The proposed method is applied to the communication of underwater steel strands． The results show that，when the emission rate changes from 400b/s to 50b/s，the stress wave communication effectiveness (SWCE) increases by 24%，and error-free communication can be realized for 256-bit sensor information; and that，when the PZT transmitter is put in the wa-ter instead of in the air，the received signal amplitudes of single and double channels both increase by 20%，while the SWCE keeps almost invariant．

Key words: multi-sensor information, spread spectrum, stress wave communication, structural health monitoring