Advanced regulatory control and advanced process control tighten complex process variables to reduce product variability.
Food engineers are applying advanced regulatory and advanced process control systems to adapt, predict and adjust to dynamic changes in complex, multivariable processes such as evaporation, drying, and pasteurization.
As shown on the pyramid on page 90, regular regulatory control (RRC) using PID (proportional, integral, derivative) loops is typically sufficient for relatively simple processes. PID control has trouble, however, dealing with more complicated processes which may be nonlinear (fluctuating); involve long time delays; are subject to frequent dynamic changes due to recipe, batch or load changes; involve complex relationships between process variables; or require control of multivariables which cannot be handled by single-loop PID controllers. PID loops also require repeated manual tuning.