Wireless monitor for aero engine shaft
Aircraft engine manufacturers are increasingly offering a so-called ‘service-based’ approach to marketing their products, where their customers are guaranteed engine safety after purchase, by using condition based maintenance techniques. To achieve this, manufacturers take on the responsibility of condition monitoring, by embedding health monitoring systems within each unitusing big data analytics. The EU-funded TSA (Telemharsh - Telemetric system acquisition in harsh environment) project was launched to develop an innovative telemetry solution for measuring engine stress. Namely, researchers introduced a new wireless system for measuring and transmitting strain and temperature data of the engine shafts. A wireless slip ring, capable of supplying more than 5 W of power to rotating aircraft components was combined with an RF communication link at 10 Mbps, and miniaturised signal processing unit, capable of multiplexing input from several channels. While avoiding the need for large energy storage capacitors, it was also designed to transmit acquired data from the rotating component to the static gateway. Electronics were split into three small boards for power conditioning; data acquisition, processing and transmission, and sensors conditioning. The high accelerations imposed by the rotation of the shaft, which are also experienced by the electronics, proved to be a major issue. The solution adopted to overcome this problem was a reduction of the components mass. The TSA team used a test bench designed to conduct experiments that reaches high acceleration as well as temperature to optimise the new telemetry system. This test bench is capable of spinning up to 50 000 rotations per minute and has the possibility to include a thermal chamber to heat the testing unit up to 200 ºC. Further testing and performance analysis is scheduled beyond the TSA project. Research and development within the project have resulted in a wireless split ring telemetry system promising to enhance the competitiveness of the EU aeronautics industry. The technology contributes to condition-based maintenance by collecting system data in harsh environments not only for aviation but also for other sectors such as space flight and nuclear energy production.
Keywords
Aero engine shaft, telemetry, preventive maintenance, TSA, signal processing unit, condition-based maintenance
