Polarimetric Radar Friction Monitoring With Triggered Road Probing

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Solution Overview

Problem

Current methods for automatically determining road friction are not versatile or accurate enough, particularly for heavy-duty vehicles, and often require frequent actuation of mechanical systems, leading to discomfort and increased wear.

Innovation Solution

A computer-implemented method using polarimetric radar to transmit signals and detect changes in road friction by monitoring backscatter and normal force, triggering a secondary physical friction estimation system only when changes are detected, which can include steering or torque pulses to probe the road surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanical friction estimation systems are actuated frequently to determine road friction, then measurement precision is improved, but device wear increases and component lifespan decreases

Engineering Contradiction:
Improveroad friction estimation accuracyVSAvoidcomponent lifespan
Core Design Contradiction:
Measurement precisionVSDuration of action of stationary object

Solution Approach 1:

The patent replaces frequent mechanical actuation with radar-based detection. A radar sensor mounted on the vehicle transmits electromagnetic waves toward the road surface and analyzes the backscatter signal characteristics to estimate road friction conditions continuously without mechanical contact, thereby eliminating wear while maintaining measurement capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs preliminary friction estimation using radar signals continuously to monitor road conditions. Only when the radar-detected friction parameter changes beyond a threshold does the system trigger mechanical friction estimation actuation, preventing unnecessary mechanical wear while ensuring accurate friction measurement when conditions change

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If mechanical friction estimation systems are actuated frequently to determine road friction, then measurement precision is improved, but discomfort to occupants increases

Engineering Contradiction:
Improveroad friction estimation accuracyVSAvoidoccupant comfort
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces frequent mechanical actuation with radar-based detection. A radar sensor mounted on the vehicle transmits electromagnetic waves toward the road surface and analyzes the backscatter signal characteristics to estimate road friction conditions continuously without mechanical contact, thereby eliminating wear while maintaining measurement capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system performs preliminary friction estimation using radar signals continuously to monitor road conditions. Only when the radar-detected friction parameter changes beyond a threshold does the system trigger mechanical friction estimation actuation, preventing unnecessary mechanical wear while ensuring accurate friction measurement when conditions change

Inventive Principle:
Principle #10Preliminary action

3Reliability

If continuous mechanical friction estimation is performed, then reliability of road friction data is improved, but energy consumption increases

Engineering Contradiction:
Improveroad friction data accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses periodic radar signal transmission to continuously monitor road friction conditions. The radar sensor transmits electromagnetic waves at regular intervals and analyzes backscatter characteristics. Mechanical actuation is triggered periodically only when radar-detected friction parameters change beyond a threshold, reducing energy consumption while maintaining data reliability

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent replaces frequent mechanical actuation with radar-based detection. A radar sensor mounted on the vehicle transmits electromagnetic waves toward the road surface and analyzes the backscatter signal characteristics to estimate road friction conditions continuously without mechanical contact, thereby eliminating wear while maintaining measurement capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This approach allows for more accurate and efficient road friction estimation, reducing unnecessary actuation of mechanical systems and minimizing wear, while providing real-time data for improved vehicle motion management.

Implementation Method 1

transmitting a radar signal by at least one polarimetric radar transceiver towards a surface supporting the vehicle and receiving backscatter from the transmitted radar signal

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

The radar signal comprises a first polarization component and a second polarization component different from the first polarization component

Methodology Applied
Scientific EffectPolarisation: Polarisation

Data Source

PatentEP4459312A1Radar-triggered road friction estimation
Publication Date: 2024.11.06 VOLVO TRUCK CORP
  • EP4459312A1 patent drawingFigure 1~2
  • EP4459312A1 patent drawingFigure 3~4
  • EP4459312A1 patent drawingFigure 5

AI summary

A computer implemented method for determining a road friction condition associated with at least one wheel (150, 160, 170, 430) on a heavy-duty vehicle (100), the method comprising transmitting (S1) a radar signal (185) by at least one polarimetric radar transceiver (180) towards a surface (101) supporting the vehicle (100), and receiving backscatter from the transmitted radar signal, where the radar signal (185) comprises a first polarization component and a second polarization component different from the first polarization component, processing (S2) the received backscatter by a processing device (130) to determine a friction parameter related to the road friction condition of the surface (101), monitoring (S3) the friction parameter over time to detect change in the friction parameter, and in case change in the friction parameter is detected, triggering (S4) friction estimation by a secondary physical friction estimation system.