Design of a networking stress wave communication method along pipelines

Abstract

Stress waves are increasingly employed in structural health monitoring (SHM) systems of pipelines based on sensor networks. Data transmission among sensors is crucial for the overall stress waves based SHM system. Since conventional communications are hampered by limited transmission ranges when in some environments, such as in soil and water, it is essential to develop an alternative approach to deal with the issues. This paper proposes a stress wave communication networking method that can be implemented among multiple sensors. The proposed work introduces Orthogonal Variable Spreading Factor (OVSF) codes to achieve multiple-access stress wave channels by using piezoelectric transducers. In this paper, both frequency-domain and time-domain channel responses are estimated, and communication schemes are thereby designed to achieve data transmission among multiple sensors based on the features of multiple channels. The experiments are conducted on a T-shape pipeline structure in the laboratory environment, and the results verify the feasibility of the method. Experimental results show that the data rate of each single channel reaches 250 bps.