# The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges
## 4 WSN Systems in Different Applications: Aerospace, Bridge Structures, and Wind Turbines
### WSN in Bridge Structures
The complete WSSN set is shown in Figure 9.  
Technological progress in technologies of Micro-Electromechanical System (MEMS) enabled the use of inexpensive and small sensors in bridge structure monitoring. The wireless MEMS-based structures are used successfully as the sensors in bridge monitoring purposes [70; 76; 77]. Many scientific, non-commercial, as well as commercial, wireless sensing unit forms have been invented in recent years. The interdisciplinary collaboration of civil engineering and computer researchers resulted in the development of the SHM-A (which stands for structural health monitoring-acceleration) sensor board for monitoring civil infrastructure. The cooperation was conducted within the Illinois SHM Project [78] (Figure 10). As the triaxial accelerometer, the ST Microelectronic's LIS344 ALH with the range of \(\pm\)2 g was used. For digitalization of the analog acceleration signals from the accelerometers, a 4-channel, 16-bit Analog to Digital Converter (ADC) was utilized. The Quickfilter QF4A512 ADC was integrated with a programmable signal conditioner which allows for setting sampling rates and program digital filters by the user. The noise levels of used accelerometers are 0.3 mg and 0.7 mg for the \(x\)- and \(y\)-axes and the \(z\)-axis, respectively. Moreover, the SHM-A board is equipped with humidity, temperature, and light sensors. Thanks to an additional analog input, the acquisition of the data from other types of sensors, including both strain gauges and anemometers, is possible. The example of an SHM-A and SHM-W (structural health monitoring-wind) board of smart wireless sensor is presented in Figure 11[79]. In this solution, the SHM-A board mea  
Figure 10: Illinois SHM Project: structural health monitoring-acceleration (also known as SHM-A) sensor board: top (**left**), bottom (**middle**), and perspective view (**right**) [78]. Figure 9: Wireless smart sensor node, WSSN [75]. sures multi-metric data while the SHM-W board measures wind parameters such as speed and direction. A three-axis anemometer is used to obtain wind parameter measurements. Polyvinylidene fluoride (PVDF), a piezoelectric polymer material, was proposed in WSN design in order to report and read the displacement and strain from PVDF thin film [80; 81]. Moreover, the IEEE802.15.4 wireless communication standard was utilized. In this solution, a constrained energy power of WSN was intended, and it was possible due to its unique features, such as extreme power competence. The disadvantage of wireless systems used in bridge structures is their relatively high energy demand, resulting from the large number of sensors needed to monitor extensive and complex structures such as, for example, suspension bridges. One solution to this problem is the use of photovoltaic panels, the installation of which on selected structural elements of the bridge is relatively easy to implement. The development of technology forces the SHM system to be characterized by sending, transmitting and analyzing data in a short time, combined with a quick and error-free assessment of the condition of the structure based on these data. In conclusion, the future wireless SHM system must achieve the goal by effectively assessing the usability, safety and durability of the structure.