Automatic Feedback Control In Support of Sensor Networks to Monitor Nitrate in Palmdale and in Merced Backyard (CON 2)
In an effort to balance water reuse and protect groundwater quality when irrigating with reclaimed water, an adaptive management scheme with feedback control has been developed and is currently undergoing testing. Several multi-level sensing arrays (pylons) equipped with soil moisture, temperature, and nitrate sensors are installed in Palmdale and in Merced backyard. The pylon is coupled to a simulation and management algorithm to optimize irrigation scheduling. Specifically, a nonlinear programming-based control algorithm, referred to as Receding Horizon Feedback Control (RHFC), is proposed to maximize water reuse and maintain nitrate concentration in groundwater below the regulatory threshold. Each pylon supplies the irrigation scheduling algorithm with real-time field information about water infiltration and distribution, nitrate propagation, and heat transport (in support of evaporation estimates). A test bed for Palmdale deployment is set up in Merced backyard. An automatic flow controller system for sprinkling is equipped with data acquisition board to interface with sensors and management algorithm in MATLABTM. One-dimensional simulators are used to estimate key local soil hydraulic and transport parameters in near real time.