Canal Control Algorithm Formulations

Over the past two decades, numerous automatic control systems have been proposed for irrigation canal operation. Types of automatic control systems range from empirically based, for a one-canal pool, to multivariable multipool procedures, based on the minimization of quadratic performance criteria. Most control algorithms can be expressed in standard control theory terminology, from which properties and characteristics can be determined. The determination of the control action or control variable required to obtain some desired canal operation as a function of the design technique used is presented. The control laws associated with the different design techniques are shown in an RST polynomial form, where R(q−1), S(q−1), and T(q−1) are polynomial matrices in the backward shift operator, q−1, associated with the control variables, controlled variables, and reference profiles, respectively. These expressions clarify the differences between the algorithms and their limitations when they are used in the opera...