On water-level error propagation in controlled irrigation channels

Abstract

We consider the propagation of water-level errors in a controlled string of (identical) pools comprising an openwater irrigation channel. It is shown that water-level errors are amplified as they propagate upstream, whenever the feedback control scheme is decentralised and load-disturbance rejection is required in steady-state. Moreover, a design trade-off is identified between local performance, in terms of set-point regulation and load-disturbance rejection, and the error-propagation characteristics. The use of feed-forward/decoupling paths is considered in terms of managing this trade-off. However, the corresponding analysis suggests it is difficult to exploit the extra degree of freedom...