Mobile communications for the factory of the future: LCM, AVL List GmbH and the Institute for Communications Engineering and RF Systems of the Johannes Kepler University Linz have joined forces to introduce wireless sensor networks, i.e. mobile communications, to modern industrial facilities. A first prototype applied at an engine test bed has been developed, which reliably transmits data while consuming such low amounts of power that the sensor nodes can rely only on solar cells for their power supply.
The common use of mobile communications in our everyday life has not yet arrived in industrial facilities with their often rough environment, even though there are plenty of applications in which Wireless Sensor Networks (WSNs) can make a difference: Many sensors sense parameters relevant for an industrial process, e.g. temperature, pressure, or flow rate. These data are sent to a central computer which computes the settings for an optimum operation of the process. This works perfectly with wired sensors since many years. However, several advantages can be realized if this would be moved to wireless: reduced installation and maintenance costs, reduction of errors due to wrong cable connections or broken cables, possibility to place sensors on positions which cannot be reached by cables, etc.
Because the requirements on the reliability and real-time capability of the wireless data transfer are much higher in industrial applications than for our ubiquitous mobile phones, scientists have been trying for quite some time to establish WSNs in industry. Existing solutions can usually not support real-time data transmission or do not offer data links for a sufficient number of sensor nodes. In a joint cooperation with AVL List GmbH and the Institute for Communications Engineering and RF Systems of the Johannes Kepler University Linz researchers at ACCM now have succeeded in developing a WSN prototype to be used for engine test beds in automotive R&D. To this end they proposed and optimized a new protocol to wirelessly transmit data from up to 100 sensor nodes in a reliable but energy efficient manner. It is now possible to use only solar cells to provide the sensor nodes with sufficient energy, if the ambient light conditions are within reasonable limits. Future research work will focus on a further reduction of the energy consumption and an increase of the reliability of the data transmission.
Impact and effects
The implemented WSN prototype proves that WSNs can be used in industrial facilities for real-time monitoring. Transferring the prototype into a product would, in a first step, reduce time and costs in operating engine test beds because no cabling is required anymore.
This type of WSN can be used in any application in which data from many (up to 100) sensors need to be periodically transmitted wirelessly via up to approx. 20 meters to a central base station. Thus it can be applied in a very wide range of scenarios.