Irrigation Control Using pF and VWC Sensors

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Solution Overview

Problem

Existing automatic watering systems lack the ability to perform irrigation operation control that is specifically suited to the soil condition, leading to adverse effects on plant growth.

Innovation Solution

A watering system that includes a water supply path, a pF sensor to detect soil condition, a VWC sensor to detect volume water content, and a control device that uses these sensors to control the irrigation operation, adjusting start and stop timings based on detected values and threshold values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If irrigation operation control is performed based on single sensor data (pF value or VWC only), then device complexity is reduced, but irrigation suitability to soil condition deteriorates

Engineering Contradiction:

Improvesensor configurationVSAvoidirrigation suitability to soil condition

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent combines data from two different sensors (pF sensor and VWC sensor) to perform irrigation control. The control device acquires both pF values indicating soil moisture status and VWC values indicating volumetric water content, then uses both parameters together to determine irrigation start and stop timings, achieving comprehensive soil condition-based irrigation control

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The irrigation control system is designed to handle multiple soil conditions and irrigation scenarios by utilizing both pF and VWC measurements. The system can adapt to different soil types and plant water requirements by processing multiple parameters, making it universally applicable to various agricultural conditions

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If irrigation stop timing is determined using fixed threshold values, then control simplicity is improved, but irrigation precision deteriorates

Engineering Contradiction:

Improvecontrol simplicityVSAvoidirrigation stop timing accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The control device continuously monitors both pF values and VWC values during irrigation operation and uses this feedback to determine when to stop irrigation. The system compares real-time sensor readings against threshold values and adjusts irrigation timing based on the combined information from both sensors, improving precision while maintaining operational simplicity

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent uses multiple parameters (pF value and VWC value) instead of a single parameter to determine irrigation timing. By considering changes in both parameters simultaneously, the system achieves more precise control over irrigation stop timing while keeping the control logic relatively simple through threshold-based comparisons

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250113788A1Watering system and control device

Publication Date: 2025.04.10 DENSO CORP

AI summary

A watering system includes a pF sensor, a VWC sensor, and a control device that controls an irrigation operation. The control device controls the irrigation using the pF value detected by the pF sensor and the volume water content detected by the VWC sensor. The control device controls a start timing of the irrigation operation based on the pF value that is detected and a start threshold value. The control device controls a stop timing of the irrigation operation, which is in operation, based on the volume water content that is detected and a stop threshold value. The control device updates the stop threshold value based on fluctuation of the pF value that is detected.