Refined convergent cross-mapping for disturbance propagation analysis of chemical processes

- Refinements have been made on the procedure of convergent cross-mapping (CCM) to improve its performance to chemical processes. It is named as RCCM.
- Different examples are tested, showing that RCCM has better performance than other methods like cross-correlation function and transfer entropy in finding propagation paths of disturbances in chemical processes.
- A benchmark process-Tennessee Eastman process is also tested by RCCM. It reveals root causes of plant-wide disturbances as well as significant time-delay relationships between variables.

In chemical processes, determining the root causes of faults and disturbances is important for improving process safety and economic profit. Recently proposed convergent cross-mapping (CCM) is suitable for both linear and nonlinear systems. However, it cannot be directly applied to chemical processes. This is because chemical processes possess characteristics, such as nonlinearity, high dimensions, continuity, and time delay, that are significantly different from ecosystems, where CCM is applicable. In this paper, we propose refined CCM (RCCM), which integrates fast embedding dimension determinations with a modified procedure to improve the speed of the calculation and accuracy of the analysis. Examples show that RCCM fits chemical processes with the above characteristics. In addition, it shows better performance than other methods in finding the propagation paths of disturbances.