Solenoid valves are essential components of industrial systems and therefore widely used. As they suffer from high failure rates in the field, fault prognosis of these assets plays a major role for improving their maintenance and reliability. In this work, Bayesian convolutional neural networks are used to predict the remaining useful life (RUL) of solenoid valves, by training them on the valve's current signatures. Predictive performance is further improved upon by using salient physical features obtained from an electromechanical model as the network's training input. Results show that our designed network architecture produces well-calibrated uncertainty estimations of the RUL predictive distributions, which is an important concern in prognostic decision-making.
I. INTRODUCTIONT HE purpose of Prognostics and Health Management (PHM) is to enable optimal maintenance strategies, as to prevent machine failure, extend the lifetime of machines and reduce operational costs. This is achieved by detecting incipient faults, fault isolation, identification of different fault types (fault diagnostics) and fault prognosis. These techniques typically imply the analysis of healthy and/or faulty conditions indicated by process measurements.Two main approaches exist for estimating the remaining useful life (RUL). Physics-based approaches rely on physical domain knowledge, which describe normal operation and physical degradation laws. Data-driven approaches are based on condition monitoring data, which are used for constructing statistical or machine learning models [1]. The term "hybrid approaches" is commonly used for approaches that combine physics-based and data-driven techniques.Deep learning (DL) techniques are an important subcategory of data-driven approaches. Features are learned automatically at multiple levels of feature representations, which allows DL to learn complex relations mapping the input to the output directly. This contrasts DL with feature-based approaches such as decision tree ensembles or Gaussian process regression, which rely on the construction of features [2]. DL is T.