Machine Condition Monitoring for Pay-per-Use Systems using Magnetoresistive Sensors

Inhalt:
Intelligent sensors, that can monitor the condition of critical machine components, are an essential „enabling technology” for availability-oriented Product-Service-Systems (PPS). Furthermore, intelligent sensors can provide information that can offered as a service. Pay-per-Use business models are now appearing in the machine tool, printing machine and packaging machine industries, which rely on accurate information about machine condition, in order to guarantee an agreed level of machine availability. Many different approaches are applied to gather information about the condition of machine elements, such as electric motors, rolling bearings or ballscrews. A classic approach is to measure vibration and an associated method is to measure acoustic emissions. Furthermore, the temperature may be measured or wear debris monitored. However, recently new approaches such as the measurement of „Instantaneous Angular Speed“(IAS) or „Motor Current Signature Analysis“(MCSA) are gaining in popularity. Both methods make special demands of the sensors used. They must not only be small, precise and robust, but must also have a wide bandwidth and a low power requirement. In addition to this, the machine builder often wishes to use existing sensors or measurement points for this extra functionality, that is, they wish to avoid the implementation of additional sensors. Magnetoresistive (MR) sensors fulfil this complex set of requirements to a very high degree. This is supported by the results from recent BMBF-funded R&D projects as well as from new industrial applications.