With the advent of Industry 4.0, the introduction of
data-driven
approaches into industrial processes for fault diagnosis has gained
substantial attention due to their significant advantage that they
mainly rely on the information on process data instead of a priori
knowledge. However, the statistically based data-driven methods have
difficulty eliminating the “smearing effect” between
variables, which affects their effectiveness and interpretability
for fault diagnosis, while the previous studies on the causal-based
fault diagnosis methods are seriously insufficient. In this study,
a novel data-driven fault diagnosis framework based on causal network
inference was developed, in which the correlations between variables
are explored by employing the partial correlation network (PC-NET)
method and the causal propagation direction are determined by a newly
developed partial conditional Granger causality (PCGC) method based
on the transfer entropy. Subsequently, the occurrences of faults are
detected by using a causal-based multivariable sensitivity enhancing
transformation (MSET) approach. Finally, a causality-attributing reconstruction-based
contribution (RBC) method is developed to isolate and identify the
fault variables and to classify the fault grade for taking remedial
measures. The effectiveness of the proposed fault diagnosis framework
is verified by its application in the actuator system of the industrial
sugar production process, and the results demonstrate that the proposed
fault diagnosis framework can not only eliminate the smearing effects
but also accurately identify fault variables and their contribution
rates, exhibiting better interpretability and scalability.