Proposal of a Cyber Physical Finite Element Sensor Network for Surface Measurements

In this paper a wireless sensor network for precise measurements of shape and deformation of arbitrarily shaped objects is presented. The network consists of multiple mechanically interconnected sensor probes applied to the surface of the object. Similar to a Finite Element Network (FEM), the object to be measured is probed into a finite number of discrete measuring points. Each sensor probe determines the surface normal and the exact distance to its neighboring probes, such that the surface shape and strain can be reconstructed from wirelessly transmitted sensor data. This is particularly interesting for real-time monitoring of large scale components, as measurement times are significantly lower when compared our approach with conventional measuring methods. Additionally, this system can be easily attached and detached to and from the object's surface employing vacuum suction cups for the probes. In comparison with, e.g., surface deformation measurements employing strain gauges, the costs for a sensor probe together with its mechanical interconnections are considerably higher, but all possible mechanical deformations can be detected without leaving residues on the surface of the object to be measured, which are often difficult to remove. And, of course, the measurement system can be reused.