Weather-Based Irrigation Controller with Historical Backup Mode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing irrigation systems face inefficiencies due to user forgetfulness in adjusting watering schedules with seasonal changes, and weather sensor malfunctions lead to wasteful or destructive watering, as users often fail to reduce irrigation duration after summer months, and sensors may malfunction, causing the system to continue using excessive water during fall and winter.
Innovation Solution
A controller that uses a combination of real-time sensors and historical data to adjust irrigation schedules, incorporating a rain gauge and thermometer to calculate irrigation duration based on rainfall and temperature, with a backup 'historical mode' to continue optimal watering even if sensors fail, using stored evapotranspiration rates and solar radiation data to adjust irrigation times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If weather sensors are mounted to monitor real-time environmental conditions, then irrigation adjustment accuracy is improved, but sensor reliability deteriorates due to exposure to elements causing malfunction
Solution Approach 1:
The system pre-calculates and stores expected irrigation durations for each month based on historical evapotranspiration data before the irrigation season begins. When sensors fail, the controller automatically retrieves the pre-calculated duration for the current month, eliminating the need for real-time sensor data and maintaining accurate irrigation scheduling without sensor malfunction risks.
Solution Approach 2:
The system creates a backup copy of the irrigation scheduling function by using historical monthly average evapotranspiration data as a substitute for real-time sensor measurements. This copied approach replicates the essential irrigation adjustment capability without requiring vulnerable physical sensors exposed to environmental elements.
2Loss of energy
If users manually adjust irrigation duration seasonally, then water conservation is improved, but user forgetfulness causes overwatering during fall and winter
Solution Approach 1:
The irrigation controller automatically performs seasonal irrigation duration adjustments without requiring user intervention. The system self-adjusts by retrieving pre-calculated monthly irrigation durations based on historical evapotranspiration data, eliminating human forgetfulness and ensuring consistent water conservation throughout the year.
Solution Approach 2:
The system incorporates automatic feedback mechanisms that monitor the irrigation schedule and adjust durations based on seasonal patterns. The controller compares current operational parameters against pre-stored monthly targets and automatically modifies irrigation duration to match seasonal requirements, preventing both overwatering and underwatering.
3Speed
If real-time sensor data is used to adjust irrigation, then responsiveness to weather changes is improved, but system complexity increases due to sensor maintenance requirements
Solution Approach 1:
The system replaces expensive, maintenance-intensive real-time weather sensors with a simple, durable database of historical evapotranspiration data. This substitution uses inexpensive, long-lasting stored information instead of vulnerable electronic sensors, dramatically reducing system complexity and maintenance requirements while maintaining irrigation accuracy.
Solution Approach 2:
The system extracts and removes the vulnerable sensor components from the irrigation control system. By separating the irrigation scheduling function from real-time sensor dependency and using pre-calculated historical data instead, the system eliminates maintenance complexity while preserving the essential capability to adjust irrigation seasonally.
Data Source
AI summary
A weather based irrigation controller has a thermometer that provides a temperature signal to the controller and a rain gauge that provides a rainfall signal to the controller, for adjusting irrigation schedules. A default mode is initiated when either sensor fails, and introduces an adjustment to the maximum irrigation duration based on historical stored data.