Wheel Electrostatic Sensing for Wet and Dry Road Detection

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Solution Overview

Problem

Existing road condition detection technologies for vehicles face limitations in applicability, reliability, and robustness to external factors, with sensors having limited durability and reliability.

Innovation Solution

A road condition detection device integrated with a vehicle wheel uses an electrostatic charge variation sensor and a processing unit to jointly process rotation speed and charge variation signals to distinguish between wet and dry road conditions, utilizing electrostatic charge generation and triboelectric effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar technology is used to detect road surface conditions, then direct detection capability is improved, but device complexity and cost increase

Engineering Contradiction:

Improveroad condition detection accuracyVSAvoidsensor system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex radar systems with a simple electrostatic sensor that detects charge variations on the road surface. Instead of using electromagnetic waves and complex signal processing, the invention uses electrostatic field interactions to directly measure road conditions, dramatically simplifying the device while maintaining detection capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts only the essential detection function from complex sensor systems. By using a simple electrostatic sensor to detect charge variations, it isolates the core measurement need from the complexity of radar, acoustic, or image processing systems

Inventive Principle:

Principle #2Taking out (Extraction)

2Measurement precision

If multiple sensors are used to improve detection reliability, then measurement accuracy is improved, but sensor durability and system reliability deteriorate due to more failure points

Engineering Contradiction:

Improveroad condition detection accuracyVSAvoidsensor durability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent extracts the essential detection function from multiple sensor systems and implements it with a single electrostatic sensor. This reduces the number of components that can fail while maintaining the ability to detect road conditions accurately through charge variation measurement

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The electrostatic sensor used in the invention is a simple, robust component with no moving parts, making it highly durable and resistant to failure. The sensor can be easily replaced if needed, and its simple construction ensures long operational life in harsh automotive environments

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Device complexity

If indirect detection methods are used, then device complexity is reduced, but measurement precision and reliability deteriorate

Engineering Contradiction:

Improvedetection system complexityVSAvoidroad condition detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces indirect detection methods (which infer road conditions from vehicle dynamics) with direct electrostatic field measurement. The electrostatic sensor directly measures charge variations on the road surface, providing accurate direct detection while keeping the device simple and sensor-less

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention creates an electrostatic copy or representation of the road surface conditions by measuring the charge distribution. This electrostatic field mapping provides direct information about road conditions without requiring physical contact or complex mechanical sensors

Inventive Principle:

Principle #26Copying

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 solution provides accurate and reliable road condition classification, reducing false detections and ensuring robustness across various vehicle speeds with low energy consumption and sensor durability, enabling effective vehicle system adjustments.

Implementation Method 1

an electrostatic charge variation sensor, configured to provide a charge variation signal indicative of an electrostatic charge variation associated with rotation of the wheel

Methodology Applied

Scientific EffectTriboelectric effect: Triboelectric Effect

Data Source

PatentUS12441324B2Device and method for automatic detection of road conditions for vehicle applications

Publication Date: 2025.10.14 STMICROELECTRONICS SRL

AI summary

A road condition detection device, to be coupled to the wheel of a vehicle, is provided with: an electrostatic charge variation sensor, to provide a charge variation signal indicative of an electrostatic charge variation associated with the rotation of the wheel; and a processing unit, coupled to the electrostatic charge variation sensor to receive the charge variation signal and furthermore for receiving a rotation speed signal indicative of the rotation speed of the wheel. In particular, the processing unit jointly processes the rotation speed signal and the charge variation signal to detect a road condition of a wet road condition and a dry road condition.