“…To cope with non‐linearities, disturbances, integral wind‐up and other complex issues in process systems, a number of cascade control strategies have been developed to improve either the outer loop performance or the inner loop performance or both. Examples such as the linear quadratic (LQ) self‐tuning controller [20], neuro‐fuzzy generalised predictive controller [1], model predictive controllers [2, 6, 7, 19] and neural network (NN)‐based controllers [3, 18] were reported for the outer loop primary controller design. Control algorithms have also been developed for the design of the secondary controller in the inner loop, for example, model‐reference adaptive control based on Kalman active observer [19], predictive control [6, 7] and sliding mode control [9], to name a few.…”