Reconfiguration schemes to mitigate faults in automated irrigation channels

The infrastructure associated with an automated irrigation channel contains a large number of actuators (electro-mechanical gates) and water level and gate position sensors. Actuator and sensor faults happen from time to time, and they will lead to loss of water and reduced service to farmers unless corrective action is taken. In this paper strategies for dealing with such faults are presented. Sensor faults are dealt with by estimating the value of the signal measured by the faulty sensor and using the estimated signal as input to the controllers. An actuator fault necessitates a relaxation of the control objectives, and it requires a reconfiguration of the controller. The developed methods were successfully tested on an operational irrigation channel. Despite the faults, very good control performance was achieved, and there were no disruptions to the operation of the channel.