Garden Tool Plate Capacitor Soil Moisture Sensor

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Solution Overview

Problem

Existing gardening tools for soil tilling and seeding/planting are either too expensive or complex for hobby gardeners, and existing soil sensors are cumbersome to use and not fully exploited in their benefits.

Innovation Solution

A gardening tool with a handle and ground contact portion, equipped with a moisture detection device using a plate capacitor design, a nutrient detection device for electrical conductivity measurement, and a computing unit to compare soil conditions with target values for specific plants, providing a user-friendly interface for selecting plants and determining suitable soil conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex soil sensors with multiple components are used to achieve accurate soil moisture and nutrient detection, then measurement precision is improved, but device complexity increases and cost increases

Engineering Contradiction:
Improvesoil moisture detection accuracyVSAvoidsensor construction complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor is divided into separate functional components: a moisture sensor unit with capacitive electrodes and a nutrient sensor unit with Ag/AgCl electrodes. Each unit independently measures specific soil parameters, allowing simplified construction for each function while maintaining overall measurement precision through modular integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A reference electrode serves as an intermediary element that enables both moisture and nutrient measurements. The reference electrode works with the capacitive electrodes for moisture detection and with the working electrodes for nutrient detection, eliminating the need for separate reference electrodes for each measurement type and reducing overall device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple sensors are integrated into the gardening tool to provide comprehensive soil analysis, then measurement precision is improved, but ease of operation deteriorates due to complex handling

Engineering Contradiction:
Improvesoil nutrient detection accuracyVSAvoidhandling simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The moisture sensor, nutrient sensor, and reference electrode are integrated into a single gardening tool handle assembly. The tool combines multiple sensing functions in one unified device that is operated through simple insertion into the soil, eliminating the need for gardeners to handle multiple separate sensors and maintaining ease of operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gardening tool is designed as a multi-functional device that simultaneously performs moisture measurement, nutrient measurement, and pH detection. The universal tool replaces multiple specialized instruments, providing comprehensive soil analysis through a single device that maintains simple handling characteristics.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If advanced sensor technology is used to achieve reliable soil condition detection, then reliability is improved, but cost increases making it unsuitable for hobby gardeners

Engineering Contradiction:
Improveseeding decision accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sensor electrodes are designed using cost-effective materials such as Ag/AgCl and capacitive structures that can be manufactured at low cost. The tool is positioned as an affordable, potentially disposable or limited-life device for hobby gardeners, eliminating the need for expensive industrial-grade components while maintaining sufficient reliability for amateur use.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The measurement parameters are optimized for hobby gardening applications rather than industrial precision requirements. The sensor design uses practical parameter ranges and measurement thresholds suitable for home gardeners, allowing simplified electronics and lower-cost components while maintaining adequate reliability for the target application.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The tool allows for reliable and simple seeding or planting by providing accurate soil moisture and nutrient content readings, ensuring optimal conditions for planting, while being cost-effective and easy to use.

Implementation Method 1

the moisture detection device has two first electrodes which are mounted on the ground contact section at a distance from one another in the manner of a plate capacitor such that a capacitance of the plate capacitor with ground as the dielectric is influenced when the ground with the ground contact section is in the region is contacted between the electrodes

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a nutrient detection device for detecting a number of variables corresponding to nutrient content in the soil

Methodology Applied
Scientific EffectElectrical Conductivity: Conduction (electrical)

Data Source

PatentEP3381251B1Garden device for cultivating soil and sowing or planting method with the aid of such a garden device
Publication Date: 2019.07.24 SCHWEPPACH FAB VON HOLZBEARBEITUNGSMASCHINEN GMBH
  • EP3381251B1 patent drawingFigure 1
  • EP3381251B1 patent drawingFigure 2
  • EP3381251B1 patent drawingFigure 3

AI summary

The invention relates to a garden tool for soil cultivation, comprising a handle section, a soil contact section attached thereto, a power supply, a moisture detection device for detecting a number of parameters corresponding to soil moisture, a nutrient detection device for detecting a number of parameters corresponding to nutrient content in the soil, a processing unit for calculating soil moisture from the number of parameters corresponding to soil moisture and nutrient content from the parameters corresponding to nutrient content, and an output device for outputting the soil moisture and nutrient content in the soil. The invention is characterized in that the moisture detection device has at least two first electrodes (3, 4) spaced apart from each other on the soil contact section in the manner of a plate capacitor.wherein the capacitance of the plate capacitor with earth as the dielectric is influenced when the earth is contacted with the ground contact section in the area between the electrodes (3, 4), wherein the garden device has a user interface, a selection program of garden plants and/or vegetable species selectable via the user interface, in which favorable target values ​​for soil moisture or nutrient content in the soil for the garden plants and/or vegetable species are stored, and a comparator device which compares the stored target values ​​for the selected garden plant or vegetable species with the measured actual values ​​for soil moisture and/or nutrient content in the soil and transmits the result for output on the output device. The invention further relates to a sowing or planting method to be carried out with the garden device.