Vehicle Event Recorder Test System Using Electrodynamic Shaker

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Solution Overview

Problem

Existing test systems for characterizing the accuracy of vehicle event recorders with accelerometers are limited by long test durations, high costs, excessive space requirements, poor repeatability, and inability to control impact accelerations precisely, due to physical damage and variability in vehicle and stress system characteristics.

Innovation Solution

A test system comprising a vehicle event recorder with a triaxial accelerometer, an actuation system for controlled acceleration profiles, a fixing system for precise mounting, and a control system for normalizing and synchronizing signals from the recorder and a high-performance reference sensor, allowing for reproducible and controllable acceleration simulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If physical impact tests are used to characterize accelerometer accuracy, then measurement data can be obtained, but test duration becomes excessively long and test costs increase

Engineering Contradiction:
Improveaccelerometer accuracy characterizationVSAvoidtest running time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces physical mechanical impact systems with an electrodynamic shaker table that applies controlled accelerations electronically. This substitution eliminates the need for repeated physical crash tests, dramatically reducing test duration while maintaining measurement precision through programmable acceleration profiles.

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

Solution Approach 2:

The patent performs preliminary calibration of the test system using reference accelerometers with known characteristics before conducting actual measurements. This preliminary action establishes accurate reference data that enables precise accelerometer characterization without requiring multiple repeated physical impact tests.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If physical impact tests are conducted to test vehicle event recorders, then accuracy data can be obtained, but the area required for testing becomes excessively large

Engineering Contradiction:
Improverecorder accuracy characterizationVSAvoidtest area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent replaces large-scale physical impact facilities with a compact electrodynamic shaker table system. This substitution consolidates the testing infrastructure into a much smaller footprint while maintaining the capability to generate required acceleration levels through electromagnetic actuation rather than mechanical impact.

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

3Measurement precision

If physical crash tests are used to characterize accelerometer performance, then measurement data is obtained, but test repeatability deteriorates due to structural variability

Engineering Contradiction:
Improveaccelerometer reading fidelityVSAvoidtest repeatability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces physical crash structures with a rigid, instrumented test fixture mounted on an electrodynamic shaker table. This substitution eliminates structural variability between tests because the same rigid fixture and controlled acceleration source are used repeatedly, ensuring high test repeatability while maintaining measurement precision through stable mounting conditions.

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

Solution Approach 2:

The patent changes the fundamental test parameter from uncontrolled physical impact to programmable electrodynamic acceleration. This allows precise control and reproduction of acceleration magnitude, direction, and waveform, ensuring that identical test conditions can be repeatedly applied while maintaining consistent measurement quality.

Inventive Principle:
Principle #35Parameter changes

4Force

If physical impact systems are used to provide test accelerations, then acceleration can be applied, but control over spatial components of acceleration deteriorates

Engineering Contradiction:
Improveimpact accelerationVSAvoidacceleration control
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent replaces mechanical impact systems with an electrodynamic shaker table that applies accelerations through electromagnetic forces. This substitution enables precise electronic control of acceleration magnitude, direction, and temporal profile, making it easy to apply specific acceleration components along different spatial axes while maintaining the ability to generate high impact-level accelerations.

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

The system enables efficient, cost-effective, and highly reproducible testing of vehicle event recorders by simulating various acceleration profiles without physical damage, reducing test time and space requirements, and improving accuracy through precise control and comparison of recorded signals.

Implementation Method 1

The DUT comprises at least one accelerometer adapted to detect the occurrence of the impact

Methodology Applied
Scientific EffectAccelerometer: Accelerometer

Implementation Method 2

an actuation system for controlled acceleration profiles

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3474022B1Test system for a vehicle event recorder provided with an accelerometer, and a method thereof
Publication Date: 2022.11.30 GENERALI JENIOT S P A SOC A SOCIO UNICO
  • EP3474022B1 patent drawingFigure 1
  • EP3474022B1 patent drawingFigure 2
  • EP3474022B1 patent drawingFigure 3

AI summary

Test system (1) of a vehicle event recorder (DUT, 9) configured to identify and record an impact caused by a road accident and provided with at least one accelerometer. The test system comprises a control system (7), configured to acquire (78), from a database, at least one input acceleration profile (Ain(t)), a mobile platform (22) under the thrust of a actuation system (2) and provided with a support (3; 43) configured to permanently carry the event recorder and a reference sensor (4) arranged on the support (3; 43) and configured to detect a reference acceleration (Aref(t)) during a movement operation of said mobile platform (22) according to the selected acceleration profile. The control system (7) compares the reference acceleration (Aref(t)) the measured acceleration (Aout(t)), detected by said event recorder (9) during the movement operation of the mobile platform (22).