Application of virtual sensors for stress-related design and operation-specific lifetime prognosis

In this article, a procedure for the application of virtual sensors for load-related sizing and lifetime prognosis of components of large diesel engines is presented. Due to high costs for testing to assure the lifetime of a large diesel engine, the knowledge about the load is of utmost importance. The approach consists of several steps beginning with the identification of the relevant loads on specific components and ends with either a prognosis of the remaining useful life (RUL) or the use of load spectrums for the development. Virtual sensors are models that use given input variables to estimate an undetected output variable of the system. Thus the load of the system during the installation is determined. The load-time signal can be used for both a stress appropriate design as well as a prediction of the remaining useful life. The necessary steps for deriving requirements for the development process as well as the lifetime prognosis are described.