LiDAR Cover Strain Sensing for Foreign Substance Detection

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Solution Overview

Problem

Existing sensor systems installed on vehicles face degradation in information detecting capability due to foreign substances adhering to the cover, which obstructs the detection of outside information, leading to reduced performance in driving support systems.

Innovation Solution

A sensor system is designed with a displacement sensor, such as a strain gauge or optical fiber sensor, on the cover to detect changes in strain caused by foreign substances, and a processor to identify and address these substances, potentially using a nozzle for automated cleaning, ensuring uninterrupted information detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sensor unit is covered by a cover forming part of the outer surface, then the sensor unit is protected and integrated into the vehicle appearance, but foreign substances may adhere to the cover and obstruct light passage, degrading detection capability

Engineering Contradiction:
Improvesensor unit protectionVSAvoidforeign substance adhesion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The displacement sensor is installed on the cover to detect foreign substance adhesion in advance. By monitoring strain changes before they significantly obstruct the sensor unit, the system can trigger cleaning operations proactively, preventing degradation of detection capability rather than reacting after damage occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The displacement sensor provides continuous feedback on the cover's strain state. When foreign substances adhere to the cover, they alter the strain distribution, which the displacement sensor detects. This feedback loop enables real-time monitoring and triggers appropriate responses (cleaning operations) to maintain sensor unit performance.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If a displacement sensor is added to detect foreign substances, then detection capability is improved, but device complexity increases

Engineering Contradiction:
Improveforeign substance detectionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The displacement sensor serves multiple functions: it monitors the structural integrity of the cover, detects foreign substance adhesion through strain changes, and provides data for triggering cleaning operations. By making the displacement sensor multi-functional, the patent avoids adding separate sensors for each function, thereby limiting the increase in device complexity while maintaining high measurement precision for foreign substance detection.

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

3Object-affected harmful factors

If the cover is vibrated to remove foreign substances, then cleaning effectiveness is improved, but energy consumption increases

Engineering Contradiction:
Improveforeign substance removalVSAvoidcover vibration energy
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The cover vibration for foreign substance removal is performed periodically or on-demand based on displacement sensor detection, rather than continuously. The system monitors strain changes, and only activates vibration when foreign substances are detected, thereby maintaining cleaning effectiveness while significantly reducing overall energy consumption compared to continuous vibration.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses the displacement sensor to autonomously detect when cleaning is needed and triggers the vibration mechanism automatically. This self-service approach eliminates the need for continuous monitoring or manual intervention, optimizing the balance between cleaning effectiveness and energy consumption by performing vibrations only when necessary.

Inventive Principle:
Principle #25Self-service

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 effectively detects and removes foreign substances, maintaining the sensor's information detecting capability and enhancing the reliability of driving support systems by preventing obstruction and noise interference.

Implementation Method 1

a displacement sensor disposed on the cover and configured to output a signal corresponding to displacement of the cover

Methodology Applied
Scientific EffectStrain detection: Elasticity

Implementation Method 2

As the displacement sensor, for example, at least one of a strain gauge

Methodology Applied
Scientific EffectStrain gauge measurement: Piezoresistive Effect

Implementation Method 3

In a case where the optical fiber sensor is used as the displacement sensor

Methodology Applied
Scientific EffectOptical fiber sensing: Optical Fibre

Implementation Method 4

the sensor system may include an actuator for vibrating the cover

Methodology Applied
Scientific EffectMechanical vibration: Vibration

Implementation Method 5

by actively vibrating the cover, it is possible to make the change of the vibration mode detected by the acceleration sensor more remarkable

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentEP3882658B1Sensor system
Publication Date: 2024.12.11 KOITO MFG CO LTD
  • EP3882658B1 patent drawingFigure 1
  • EP3882658B1 patent drawingFigure 2
  • EP3882658B1 patent drawingFigure 3A~3B

AI summary

A LiDAR sensor unit (14) is configured to detect information of an outside area of a vehicle with sensing light (14a). A cover (12) covers the LiDAR sensor unit (14) so as to allow passage of the sensing light (14a) while forming a part of an outer surface of the vehicle. A strain gage (15) is disposed on the cover (12) and configured to output a strain signal (S11) corresponding to strain generated in the cover (12). A processor (162) is configured to detect a foreign substance adhered to the cover (12) based on the strain signal (S 11).