Miniature mobile sensor platforms for condition monitoring of structures

In this paper, a wireless, multisensor inspection system for nondestructive evaluation (NDE) of materials is described. The sensor configuration enables two inspection modes-magnetic (flux leakage and eddy current) and noncontact ultrasound. Each is designed to function in a complementary manner, maximizing the potential for detection of both surface and internal defects. Particular emphasis is placed on the generic architecture of a novel, intelligent sensor platform, and its positioning on the structure under test. The sensor units are capable of wireless communication with a remote host computer, which controls manipulation and data interpretation. Results are presented in the form of automatic scans with different NDE sensors in a series of experiments on thin plate structures. To highlight the advantage of utilizing multiple inspection modalities, data fusion approaches are employed to combine data collected by complementary sensor systems. Fusion of data is shown to demonstrate the potential for improved inspection reliability

Simulation and implementation of ultrasonic remote sensing agents for reconfigurable NDE scanning

Remote Sensing Agents (RSAs), in the form of miniature robotic platforms, offer unique possibilities for structural inspection. Autonomous groups of RSAs can quickly cover large areas, access hazardous and inaccessible environments and work together intelligently to detect, localize and identify defects. This paper describes such a concept, using wireless RSAs that incorporate air-coupled Lamb wave ultrasonic sensors, combined with magnetic traction. The work focuses on reconfigurable array scanning in plates, where the ability to reconfigure the scanner intelligently requires an understanding of the ultrasonic wave generation, its propagation and the mechanics, positioning and control of the RSAs. To this end, a simulation of the complete system has been created. Ultrasonic generation has been modeled by the Linear Systems 1D Model; the resulting wave propagation is modeled in 3D using the Local Interaction Simulation Approach and a dynamic simulation of the RSA was used to model the transducer positions. The complete model is used to evaluate and optimize inspection strategies