Application of time-space neighborhood standardization technology to complex multi-stage process fault detection

To solve the problem that the multi-stage process with dynamicity and nonlinear is hard to monitor effectively, the time-space neighborhood standardization (TSNS) method is proposed, which is further applied to partial least squares (PLS) to propose TSNS and PLS (TSNS-PLS) method for process fault detection. TSNS can transform multi-stage data into single-stage data that approximately obeys a standard normal distribution, remove temporal correlation between samples at previous and subsequent moments in the process data, and separate online fault samples. TSNS makes the transformed process data satisfy the requirements of the PLS method for process data and can significantly improve the fault detection rate of the PLS method. Finally, the performance of TSNS-PLS was examined by a numerical simulation process and the penicillin fermentation process design fault detection experiment.