Automotive LED Failure Detection Using Temperature Profile Comparison

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Solution Overview

Problem

Detecting individual failures in solid-state light sources within automotive lighting devices, such as LEDs, is challenging due to their dependence on temperature, especially in modules with thousands of LEDs, where only global voltage and current measurements are available, making it difficult to identify a specific LED failure before it occurs.

Innovation Solution

A method involving an estimated temperature profile comparison with actual temperature profiles, using machine learning algorithms and temperature sensors, to detect and isolate failures by activating specific lighting functionalities like ADB or HW to verify temperature deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If only global voltage and current measurements are used to monitor lighting device, then device complexity is reduced, but measurement precision deteriorates making it impossible to detect individual LED failures

Engineering Contradiction:

Improvemonitoring system complexityVSAvoidLED failure detection precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The invention segments the monitoring approach by dividing the lighting device into multiple zones and using different measurement resolutions for different regions. Temperature sensors are strategically placed in specific zones rather than uniformly distributed, allowing individual LED failure detection through localized temperature anomalies while keeping the overall system complexity manageable.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces temperature as an intermediary parameter to detect LED failures. Instead of directly measuring electrical parameters of each LED, the system uses temperature sensors to detect heat generation patterns, which serve as an indirect indicator of LED performance and failure states, thereby achieving precise detection without complex direct measurement systems.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If temperature sensors are added to detect individual LED failures, then measurement precision improves, but device complexity increases

Engineering Contradiction:

ImproveLED failure detection precisionVSAvoidsensor system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The lighting device is divided into multiple zones with temperature sensors placed strategically in each zone rather than every LED position. This segmented approach allows detection of localized temperature anomalies indicating LED failures while minimizing the total number of sensors required, thus balancing detection precision with system complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The temperature sensors serve multiple functions: detecting LED failures, monitoring thermal management effectiveness, and providing data for predictive maintenance. This multi-functionality justifies the added complexity by extracting maximum value from each sensor installation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If thermal management system is enhanced to prevent LED failures, then reliability improves, but device complexity and energy consumption increase

Engineering Contradiction:

ImproveLED operational reliabilityVSAvoidthermal management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary thermal analysis by continuously monitoring temperature patterns and comparing them against expected profiles. By detecting deviations before they cause failures, the system takes preliminary action to prevent LED failures rather than reacting after failures occur, thereby improving reliability without requiring complex preventive measures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The thermal management system uses feedback from temperature sensors to dynamically adjust cooling strategies and alert systems. Temperature data feeds back to the control unit which adjusts fan speeds, coolant flow, or generates maintenance alerts, creating a closed-loop system that improves LED reliability through continuous monitoring and adaptive response.

Inventive Principle:

Principle #23Feedback

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 precise detection and isolation of failing LEDs by comparing estimated and actual temperature profiles, confirming failures through varied lighting patterns, enhancing reliability and maintenance efficiency.

Implementation Method 1

measuring an actual temperature profile of the lighting device

Methodology Applied

Scientific EffectThermal energy detection: Thermal Radiation

Implementation Method 2

solid-state electroluminescence, which uses semiconductors to convert electricity into light

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS12434629B2Method for detecting a failure in a solid-state light source of an automotive lighting device and automotive arrangement

Publication Date: 2025.10.07 VALEO VISION SA

AI summary

This invention provides a method for detecting a failure in a solid-state light source of an automotive lighting device. This method provides an estimated temperature profile for the lighting device, measures an actual temperature profile of the lighting device and compares the estimated temperature profile with the actual temperature profile in order to detect a difference between them.