Closed-Loop Irrigation

Design Specifications


Sensor and Outlet Positioning

Sensor and Outlet Positioning

Design Framework

The subsections below describe the functions of the closed-loop irrigation system and the context in which it will operate.

System Definition

Purpose:

The purpose of the closed loop irrigation system is to provide automated control and feedback in the watering of crops, so that energy and water can be conserved while requiring minimal human interaction.


Performance Requirements

The closed-loop irrigation system must be capable of performing the following functions. Performance requirements will be designated by the application as determined by the consumer. Simply put, the irrigation system will properly hydrate all plants designated to the system while minimizing power and water usage.

Application Site Resources/Characteristics

The system is designed to be compatible to a wide variety of terrains, environments and climates. However, because the focus of the design is on minimizing water consumption, it will be most beneficial to arid and dry climates. Overall, the design will be employed wherever an efficient, independently functioning irrigation system is required. Modifications will be necessary to personalize each consumer's experience with our closed-loop irrigation design.


Physical Characteristics

Environmental Characteristics

Irrigation FieldIrrigation Field

Application Site Resources

Facility Power: Electrical power: 120V 60Hz, Single Phase

Utilities:

Water Supply

  • Water Supply Capacity: 50 gallons of fresh water per acre per day

  • Ideal Water Pressure from Municipal Source: 60 Psi


Electrical/Informational Grid

  • Tauchflex-R, submersible cable. Ideal for applications involving water while ensuring safety.

  • CPU with capabilities to run Arduino Mega 2560

  • Proper electrical connections, fixtures, and an electrical panel box with appropriate fuses


Data Sources

  • Wireless communication will take place between all devices in the network. i.e. Arduino, CPU, Moisture Sensors


Performance Requirements

  • Adequate Water Supply

    • Deliver a specified flow rate over a given amount of time

    • Source must meet capacity requirements

  • Soil Moisture Sensing

    • Able to measure local moisture content

    • Response time <1 second

    • Outputs voltage proportional to moisture content

  • Signal Interpretation and Control Computer

    • Reads and interprets moisture sensor data

    • Ability to actuate all solenoids

    • Ability to turn pumps on/off

  • Safety Systems

    • Utilizes blow off valves to relieve excess pressure

    • Manually operated valves located at origin of piping network

    • Computer override via user for direct control of system devices

    • Fuses at all electrical branches to minimize fire and electrical hazard

  • Reliability

    • Ability to operate in all weather conditions

    • Electronics protected from electromagnetic surge

    • Corrosion resistive materials

    • Waterproof and insulated electrical wiring

    • Valves, pumps, sensors, and computer lifetime of approximately 10 years

  • Processed Materials

    • Polyvinyl Chloride (PVC)

      • Tensile Strength: 4900 psi - 9000 psi

      • Density: 81 lb./ft3 - 91 lb./ft3

      • Min. Thickness: .068 in. – .091 in.


Modelling and Programming Software

  • ASVIC - Mech Q Piping CAD Software

  • OmniCADD - Hydraulic Calculations Software

  • AUTOCAD - P&ID

  • PTC Creo 3.0

  • MATLAB 2016a

  • Microsoft Excel 2016