Embedded systems must be designed to cohesively integrate with current agricultural practices, and take advantage of existing infrastructure.
Electrical and Computer Engineering master’s student Brian Gross is designing an automated drip irrigation valve network, for which the barn will serve as it’s central hub. To learn more about Brian, check out WHO WE ARE.
About the AIV Network
Automation of individual duties by embedded systems, culminating in a collectively automated agricultural system, has the potential to decrease the physical demand on farmers, increase the precision of agricultural operations, and increase both crop and economic yields.
These embedded systems must be reliable and simple to interact with and install, thus minimizing potential user resistance to change. In addition, this technology must improve the user’s job in a manner proportional to its cost, for example by relieving manual labor or consolidating information that is difficult to access. Brian is leading research and development plans for an Automated Irrigation Valve (AIV) network designed to meet the above criteria. The proposed AIV is designed to integrate with a standard drip irrigation valve. A microcontroller will be built onto the periphery of this mechanical valve to control the unit and simplify installation. The AIV units will also have backups for all primary electrical systems. The ability to manually control the valve will be maintained, in the case that the system should totally fail.
The microcontroller will serve two main purposes: (1) automating the watering cycle, and (2) monitoring waterflow for leak detection. Information will be transmitted by radio back to a central hub, allowing the user to schedule waterings and continuously track entire fields for leaks. Individual valves will be built in a modular, nodal system, allowing as many units as desired to make up the network. Individual valves will recognize their presence in the network and self-integrate. The central hub will track the network and update a smart GUI accordingly.
The AIV nodes represent a physical location, and can operate as transceivers to relay information back to the central hub. The system of radio beacon nodes in the AIV network will establish foundational infrastructure for future automation efforts, with the potential to function as a “nervous system” for the farm.
The main purpose of the AIV’s is, as the name suggests, to automate watering. Automation will be achieved by a servo actuator controlled by a microcontroller, which opens the valves’ controls upon command from a central hub (in this case, the barn). When unpowered, the AIV nodes will close themselves, creating a safe “resting” state. However, the torque required to maintained a closed valve will not impede the manual override. Traditional manual control of the valve will remain.
The valves’ operation options will be determined through conversation with users. A smart GUI located at the network’s central hub interfaces the network with the user, and will be used to configure the system. It remains to be determined whether simultaneous or sequential opening/closing of the valves along the large irrigation line is preferable. Should this be irrelevant, simultaneous operation will be implemented. If sequential control is preferred, presets will be coded into the system as default choosable smart configurations. Customization of each AIV’s individual watering schedule may also be desired, but an intuitive control system for a large number of valves may be impossible.
Most user interaction, outside the initial sensor placement, takes place through the GUI at the central hub. The GUI will preferably use touch-screen controls, if they can be implemented in a durable manner. The central hub will be a separate piece of hardware, providing the user with a single point of contact to the AIV network.
Individual AIV’s will be able to detect leaks through pressure sensors, which will compare the arrival and exit water pressure between each valve (node).
By comparing the exit pressure at one node with the arrival pressure at the next, leaks in the intermediate length of hose are made apparent.
The network system protocol has four primary needs: (1) Additional nodes that can seamlessly integrate and separate. (2) The ability to transfer data across nodes for interpretation and display at the central hub, (3) Robust protocol to prevent communication hiccups from breaking the system, and (4) A central hub that updates accurately and frequently to represent the current node configuration. Verification of information from multiple nodes may also be explored to guarantee information integrity.
The primary purposes of the smart GUI are to (1) display information for the user, (2) configure automated watering times, and (3) independently instantiate new nodes. Limiting configuration and system inputs simplifies operation, which is essential for large scale adoption. The GUI must adapt to and reasonably display reasonably a fully scalable system. The GUI limits the AIV network, i.e. the GUI’s screen cannot resolve the system once too many nodes exist. The node network will hypothetically allow an infinite number of nodes.
Given the harsh outdoor environment at a farm, durability is a major governing factor of the AIV design. Each AIV will have backup copies of all hardware installed. The valves inform the user, through the GUI at the central hub, which backup they are running. The backup in operation represents the node’s need for maintenance and likelihood that it will completely fail.
Because the network must easily accommodate the addition and removal of valves, a removed AIV needs to distinguish itself from a broken valve. Otherwise, an intentionally removed valve may appear broken. Upon recognizing a broken AIV, the system must throw the user an error message. A careful communication protocol must be developed for these purposes.