Ground-Penetrating Radar Speed Sensing Beneath Disturbed Road Surfaces

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Solution Overview

Problem

Existing methods for determining vehicle speed over ground are not reliable and accurate, particularly in environments where global positioning systems fail or road surfaces have disturbances like water, snow, or moving objects.

Innovation Solution

A ground-penetrating radar transceiver with a main transmission lobe directed towards the road surface is used to detect a target point below the surface, determining speed over ground based on Doppler frequency, employing a frequency modulated continuous wave (FMCW) radar and narrow beam configuration to suppress clutter and enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ground-penetrating radar is used to detect targets below road surface, then reliability of speed measurement is improved, but device complexity increases

Engineering Contradiction:
Improvespeed measurement reliabilityVSAvoidradar system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses the road surface as an intermediary medium to access subsurface targets. By transmitting radar signals through the road surface to subsurface objects and analyzing the returned signals, the system achieves reliable speed measurement without directly observing the moving road surface, thus avoiding surface disturbance issues while using the surface as a transmission medium.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical/optical surface-based detection methods with electromagnetic wave-based ground-penetrating radar. This substitution allows penetration through the road surface to detect subsurface targets, eliminating sensitivity to surface conditions like water, snow, or debris while maintaining measurement reliability.

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

2Measurement precision

If radar detects road surface targets, then speed over ground can be determined, but measurement accuracy deteriorates due to road surface disturbances

Engineering Contradiction:
Improvespeed measurement accuracyVSAvoidroad surface disturbances
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the measurement target from the problematic road surface environment by detecting subsurface objects instead. By focusing radar detection on stationary subsurface targets rather than the disturbed road surface, the system eliminates the harmful effects of surface water, snow, and moving debris on measurement accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transitions from surface-level detection to subsurface detection by transmitting radar waves through the road surface. This dimensional change from detecting objects on the surface to detecting objects below the surface removes the measurement from the harmful surface environment while maintaining the ability to determine vehicle speed over ground.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method provides a stable and reliable estimate of vehicle speed over ground, unaffected by road surface disturbances, allowing for precise vehicle control and improved motion management.

Implementation Method 1

detecting a Doppler frequency associated with a target point at a distance below the road surface, and determining the speed over ground vx of the heavy-duty vehicle based on the detected Doppler frequency

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4460714B1Reliably determining speed over ground of a heavy-duty vehicle
Publication Date: 2026.02.25 VOLVO TRUCK CORP
  • EP4460714B1 patent drawingFigure 1~2
  • EP4460714B1 patent drawingFigure 3A~3B
  • EP4460714B1 patent drawingFigure 4~5B

AI summary

A method for determining speed over ground () of a heavy-duty vehicle (100), the method comprising configuring a ground-penetrating radar transceiver (160) with a main transmission lobe (170),detecting a Doppler frequency associated with a target point at a distance (d) below a road surface (101), and determining the speed over ground () of the heavy-duty vehicle (100) based on the detected Doppler frequency.