Postprint version. Published in Journal of Irrigation and Drainage Engineering, Volume 124, Issue 1, January 1, 1998, pages 53-57.
The definitive version is available at http://dx.doi.org/10.1061/(ASCE)0733-9437(1998)124:1(53).
Successful implementation of Proportional-Integral (PI) control logic for gate automation on irrigation canals has been problematic because of difficulties in tuning the PI controllers for a wide range of flows. This research shows that successful and relatively simple tuning for upstream controllers can be accomplished if one uses the velocity form of the PI logic. The velocity form must be modified with a newly-developed Universal Factor (UF) concept, which accounts for the nonlinearity of the upstream water level response to gate movement. The UF function is unique for each check structure, and can be determined with a steady state simulation program. The technique was tested with unsteady flow simulations of a new control system for the Highline Canal in Grand Valley, Colo. Extreme flow rate changes were successfully controlled with minimal water level changes upstream of the check structures. Robustness of the Highline Canal control system was enhanced by incorporating the use of long weir walls into the radial gate structure design.
Bioresource and Agricultural Engineering