Bumper Radar Sensor Absorption Material Integration

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Solution Overview

Problem

Radar sensors in motor vehicles are affected by interference waves from metallic and dielectric structures, leading to malfunction and falsified measurements, particularly due to rear interference radiation and multiple reflections from the bumper and trunk areas, which existing absorption screens cannot effectively address without increasing weight, cost, and logistical complexity.

Innovation Solution

Applying an absorption material outside the azimuthal detection angle on the rear side of the bumper to absorb interfering waves, eliminating the need for a separate absorption screen, thus reducing installation space, weight, and cost while ensuring reliable radar sensor operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an independent absorption screen is used to absorb rear interference radiation, then the radar sensor reliability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveradar sensor reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The absorption screen is merged with the bumper structure, integrating the interference absorption function into the existing vehicle component. The bumper serves dual purposes: structural protection and electromagnetic interference absorption, eliminating the need for separate absorption screens and reducing overall system complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bumper is designed to perform multiple functions simultaneously: structural support, collision protection, and electromagnetic wave absorption. By making the bumper multi-functional, the patent eliminates dedicated absorption components while maintaining radar reliability

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

2Reliability

If an independent absorption screen is used to absorb rear interference radiation, then the radar sensor reliability is improved, but the weight increases

Engineering Contradiction:
Improveradar sensor reliabilityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The absorption functionality is combined with the bumper structure, so no additional weight-bearing components are needed. The bumper material itself provides absorption properties through its composition and structure, eliminating the weight of separate absorption screens

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If an independent absorption screen is used to absorb rear interference radiation, then the radar sensor reliability is improved, but the manufacturing cost increases

Engineering Contradiction:
Improveradar sensor reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The absorption function is integrated into the bumper manufacturing process itself. The bumper is produced with inherent absorption capabilities through material selection and structural design, eliminating the need for separate absorption screen components and their associated manufacturing and assembly costs

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bumper serves multiple functions including structural support and interference absorption, reducing the total component count and simplifying the supply chain. This multi-functionality reduces manufacturing complexity and logistical overhead

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

4Object-affected harmful factors

If absorption material is applied on the rear side of the bumper, then the interfering waves are absorbed, but the propagation of transmitted waves may be affected

Engineering Contradiction:
Improveinterference wavesVSAvoidwave propagation reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The absorption properties are localized to specific regions of the bumper that correspond to rear interference sources. The bumper structure is designed with varying absorption characteristics in different zones, ensuring interference absorption while maintaining wave transmission in the radar's field of view

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bumper structure, which could potentially cause reflections, is designed to convert harmful reflected waves into absorbed energy. The same structural elements that might cause interference are configured to absorb electromagnetic waves, turning potential harm into a beneficial interference-reduction effect

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively absorbs rear interference waves without affecting the propagation of transmitted waves, ensuring accurate target detection and reducing the overall weight and manufacturing complexity of the radar sensor system.

Implementation Method 1

an absorption material is applied in the azimuth direction outside of the cutting area on the rear side of the covering part in order to absorb interfering waves outside the azimuthal detection angle

Methodology Applied
Scientific EffectElectromagnetic wave absorption: Absorption (EM radiation)

Implementation Method 2

a radar sensor which is designed to emit electromagnetic waves through the trim part to detect target objects

Methodology Applied
Scientific EffectElectromagnetic wave transmission:

Implementation Method 3

the waves reflected by the target object to be detected and received as radar echoes

Methodology Applied
Scientific EffectElectromagnetic wave reflection: Reflection

Data Source

PatentEP2893370B1Assembly comprising a bodywork part and a radar sensor, motor vehicle and method for producing an assembly
Publication Date: 2019.04.10 VALEO SCHALTER & SENSOREN GMBH
  • EP2893370B1 patent drawingFigure 1~2
  • EP2893370B1 patent drawingFigure 3
  • EP2893370B1 patent drawingFigure 4

AI summary

The invention relates to an assembly (3) for a motor vehicle (1), comprising a bodywork part (4), in particular a bumper, and comprising a radar sensor (5, 6), which is designed for detecting target objects (12a, 12b) by emitting electromagnetic waves through the bodywork part (4) and receiving radiation echoes from the target objects (12a, 12b), wherein the radar sensor (5, 6) has an azimuthal angle of detection (phi), by which a field of view (9, 10) of the radar sensor (5, 6) in the azimuth direction is defined, and wherein the radar sensor (5, 6) is arranged at a distance (32) from a rear side (31) of the bodywork part (4), and so the azimuthal field of view (9, 10) of the radar sensor (5, 6) intersects the bodywork part (4) in a region of intersection (33). For the absorption of interference waves outside the azimuthal angle of detection (phi), an absorption material (36) is applied to the rear side (31) of the bodywork part (4) outside the region of intersection (33) in the azimuth direction, wherein the region of intersection (33) is free from absorption material (36).