Self-Organizing Wireless Sensor and Data Networks

(Selbstorganisierende mobile Sensor- und Datenfunknetze)

Reliable wireless mobile sensor and radio data transmission networks that are self-organizing and provide their own energy supply are the key to comprehensive information across countless technical and biological systems. They will open up totally new application opportunities. Where economic issues too are concerned, the increase in knowledge gained in this way will in future become more and more important.

Knowledge is power. In the technological and scientific sense, knowledge is gained by, for example, measuring component conditions or environmental parameters by means of sensor technology. The more information that can be acquired in this way, the more detailed is the picture that is desired. In practice, the uses to which sensor technology can be put are often still limited. Power cables or short-lived batteries and the sheer size and, not least, high cost of sensors today rule out interesting possibilities and advanced application areas.

This is precisely where the work of the Self-Organizing Wireless Sensor and Data Networks research center, or SomSed, to use its German abbreviation, kicks in. The many participating TUHH institutes aim to conduct research into the basic and applied technology for lasting, comprehensive measurement of physical and biological parameters, including the relevant signal evaluation technology, by means of wireless sensor networks.

These networks consist of stationary or mobile sensor nodes with measuring technology, actuators, data processing unit, energy supply and wireless radio data transmission interface integrated in the smallest space. Used principally in inaccessible places such as an aircraft’s landing gear, they can achieve a significantly higher spatial resolution for a large number of phenomena than has previously been possible. The nodes can do independent calculations—and thereby proceed immediately to intelligent processing of the data readings.

In an aircraft a wireless sensor network of this kind, generating its own energy, could inter alia monitor the condition and functioning of the many actuators that measure temperature and humidity in the cabin and keep an eye on the integrity of the wings and fuselage. This makes use of several advantages: no cables are required to supply energy, thereby reducing weight and, in the final analysis, fuel consumption; it also enables sensors to be fitted faster and easier. If you always know what condition components are in, you only need to replace them when it is really necessary and no longer need to check and replace them at regular intervals on suspicion, as it were, as is currently the case. That saves time and money.

Equally conceivable is a highly dynamic traffic monitoring system in which each car is equipped with several sensors to form a mobile node in a network of sensors. Further potential uses are in environmental monitoring at, say, a chemicals factory, or as an early warning system for volcanic eruptions, forest fires and other natural disasters. There is also a wide range of potential new uses in medical and maritime systems and logistics and robotics.

The new wireless sensor networks will not only be able to relay much more information than in the past but also be of great economic significance, especially where sensors are used in a hostile environment where taking measurements is complicated or cabling is either very expensive or impossible. That is special attention is also paid at the SomSed research center to the weather resistance, robustness and independent energy supply of sensor nodes. The target is a minimum service life of ten years. Nodes are to generate the power on which they run by using energy harvesting methods and converting inter alia vibrations, heat or light into electric power.

As potential deployment scenarios and size of networks largely rule out manual monitoring and control, the networks in question must be able to ensure that they function even when partially defective without external intervention. The theoretical basis of this is the concept of self-organization. In other words, the influences that define structure and behavior originate from the elements of the self-organizing system itself and a central control unit is dispensed with.

The vision the research center is pursuing is clear: wireless sensor networks with thousands of nodes that can be deployed flexibly and function reliably and as self-sustaining systems for a long time. This research approach is unique in Germany in its scientific diversity and size.

Homepage: https://somsed.tu-harburg.de/