Maintenance-free wireless condition monitoring
Finnish industry is seeking new solutions for condition monitoring of processes and machinery. The VTT InterSync project has engaged in close co-operation with enterprises to produce solutions such as a new type of vibration-powered energy harvester for wireless sensor nodes.
Industrial enterprises wish to enhance their operations using sensor nodes that are wireless, easy to install and maintenance-free. The InterSync project jointly run by VTT and industry has involved creating energy-efficient measuring solutions that collect energy from their environment.
One of the items developed in the project is a new kind of vibration-powered energy harvester. Vibration is generally something to be avoided, but in sensor technology it can actually be an asset. Micro-actuated electronics regulate energy production, converting the power generated by the energy harvester into a suitable voltage. The power generated by such a device is typically in the order of milliwatts. The energy harvester operates on a wide spectrum of vibrations – in this case calibrated to 10–20 Hz.
Vibration-powered energy harvesters to date have operated on very narrow spectra, but the broad-spectrum energy harvester developed by VTT needs no frequency tuning and has more potential applications. The device can also harvest energy from rotating sources.
The project has also included developing solutions for transferring power to the sensor nodes over a wireless connection. The first applications were created for the companies involved in the project.
Because the sensor systems are wireless, they are easy to install and transfer, and also more reliable. There are also aesthetic reasons for favouring a wireless system. In order to be totally wireless, the sensor must be able to communicate wirelessly and to function without an external powering cable.
There are many ways to make a wireless sensor self-sufficient in electric power. The sensor can be equipped with an energy harvester that converts energy flows in the immediate vicinity into electrical current for the sensor to use. Energy can be tapped from light, radiofrequency electromagnetic fields, the movement of the sensor itself, temperature differences in the operating environment or temperature variations over time. To activate the energy harvester and to boost its operation, a specific wireless power transmitter can be installed near the sensor to feed it the power it requires.
The sensor can be fitted with a battery lasting for the entire lifetime of the sensor, or the service life of the battery can be calibrated so that it can be replaced in connection with other maintenance work.
InterSync is a research project belonging to the EFFIMA programme run by FIMECC Oy. In addition to VTT, the research consortium includes the University of Oulu and the Tampere University of Technology. The business partners are ABB Marine, Konecranes, Kone and Metso Automation.
+358 20 722 2458