Motor Vehicle Damage Classification via Impact Sound Amplitude Envelope

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Solution Overview

Problem

Existing methods for recognizing and classifying damage incidents on motor vehicles using impact sound signals cannot differentiate between types of damage, such as dents, scratches, and major deformations, requiring optical evaluation which is impractical while the vehicle is moving.

Innovation Solution

A method that determines the amplitude envelope of impact sound signals and classifies them based on time progression, using high-pass filtering to reduce background noise and calculate signal properties like maximum amplitude, energy, and variance, allowing for accurate classification of damage incidents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If impact sound signals are used to detect damage incidents, then detection capability is improved, but classification accuracy deteriorates because different damage types cannot be differentiated

Engineering Contradiction:

Improvedamage incident detectionVSAvoiddamage type classification

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent transforms the impact sound signal from frequency domain analysis to time domain analysis by determining the amplitude envelope. This parameter transformation enables differentiation between damage types based on temporal characteristics such as rise time, decay time, and peak amplitude, thereby improving classification accuracy while maintaining detection capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies high-pass filtering to the impact sound signal before analysis to pre-remove background noise and irrelevant frequency components. This preliminary action enhances the signal quality and makes subsequent amplitude envelope analysis more effective in distinguishing between different damage types

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If optical evaluation is used to classify damage types, then classification accuracy is improved, but timeliness deteriorates because visual inspection cannot be performed while the vehicle is moving

Engineering Contradiction:

Improvedamage type classificationVSAvoidclassification time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical/optical inspection process with acoustic signal analysis. By analyzing the amplitude envelope of impact sound signals in the time domain, the system can classify damage types automatically and immediately, eliminating the need for delayed visual inspection and enabling real-time classification while the vehicle is in motion

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If detailed classification of damage incidents is implemented, then classification accuracy is improved, but computational complexity increases

Engineering Contradiction:

Improvedamage incident classificationVSAvoidsignal processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential features from the impact sound signal by determining the amplitude envelope and analyzing its time progression characteristics. This extraction approach focuses computational resources on the most discriminative parameters (rise time, decay time, peak amplitude) rather than processing the entire signal spectrum, thereby reducing computational complexity while maintaining classification accuracy

Inventive Principle:

Principle #2Taking out (Extraction)

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

Enables accurate and timely classification of damage incidents, reducing computational time and erroneous messages by differentiating between types of damage through analysis of signal properties and time-dependent characteristics.

Implementation Method 1

at least one impact sound sensor, which is connected with an evaluation unit for signal transfer

Methodology Applied

Scientific EffectAcoustic detection: Sound

Implementation Method 2

frequencies of the impact sound signal which lie below a threshold frequency are dampened by means of a filter, in particular a high-pass filter

Methodology Applied

Scientific EffectFrequency filtering: Filter (electronic)

Implementation Method 3

an amplitude envelope of the impact sound signal is determined, and in that the impact sound signal is classified on the basis of the time progression of the amplitude envelope

Methodology Applied

Scientific EffectAmplitude envelope detection:

Data Source

PatentUS9704309B2Method for recognising and classifying damage incidents on motor vehicles and a device for the same

Publication Date: 2017.07.11 HELLA GMBH & CO KGAA

AI summary

A method for recognizing and classifying damage incidents and/or contact incidents, in particular on motor vehicles, the different forms of damage incident shall be detected, evaluated and classified by way of detecting and evaluating at least one impact sound signal. An amplitude envelope of the impact sound signal is determined and the impact sound signal is classified based on the time progression of the amplitude envelope. This involves assigning different damage incidents or contact incidents to different kinds of time progression of the amplitude envelope.