Tire Acceleration Sensor Detachment Detection via Peak Ratio Analysis

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Solution Overview

Problem

The detachment of an acceleration sensor from the inside of a tire due to repeated distortions leads to inaccurate estimation of road surface conditions, as the peak level and peak interval in the sensor's output become uneven, making it difficult to determine if the sensor is still attached.

Innovation Solution

A method and apparatus that calculate the ratio of the difference between acquired acceleration information and its average value, determining sensor detachment when the ratio exceeds a preset threshold value multiple times successively, using peak levels and peak intervals from the acceleration signal or its differential signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the acceleration sensor is attached to inside of the tire, then accurate acceleration information can be acquired for road surface condition estimation, but the sensor may detach due to repeated distortions causing uneven peak levels and peak intervals

Engineering Contradiction:

Improveacceleration information accuracyVSAvoidsensor attachment reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary detection of detachment by analyzing peak level and peak interval variations before they significantly degrade measurement accuracy. By continuously monitoring these parameters and comparing against reference values, the system can identify detachment early and trigger appropriate responses, preventing inaccurate road surface condition estimation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where detected peak levels and peak intervals are continuously compared against reference values obtained when the sensor is properly attached. This feedback loop enables real-time detection of attachment status and allows the system to distinguish between actual road surface conditions and sensor detachment events, maintaining measurement reliability.

Inventive Principle:

Principle #23Feedback

2Reliability

If peak level and peak interval are used to detect sensor detachment, then detachment can be identified, but accurate road surface condition estimation becomes difficult when detachment occurs

Engineering Contradiction:

Improvesensor attachment status detectionVSAvoidroad surface condition estimation accuracy

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The system introduces peak level and peak interval analysis as intermediary indicators to detect sensor detachment. By monitoring these intermediate parameters and comparing them against reference values, the system can identify detachment events and prevent misinterpretation of road surface conditions, thereby preserving the accuracy of condition estimation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces direct physical attachment verification with a signal-based detection mechanism. Instead of mechanically checking sensor attachment, the system uses acoustic/vibrational signal analysis (peak level and peak interval measurements) to infer attachment status, enabling non-intrusive and continuous monitoring that doesn't interfere with normal sensor operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the sensor detachment is not detected, then continuous monitoring can be maintained, but erroneous road surface condition estimation occurs

Engineering Contradiction:

Improvecontinuous monitoring capabilityVSAvoidroad surface condition estimation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection of sensor detachment by analyzing peak level and peak interval variations before they lead to erroneous road surface condition estimation. By continuously monitoring these parameters and comparing against reference values, the system can identify detachment early and prevent inaccurate estimations while maintaining continuous monitoring capability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where detected peak levels and peak intervals are continuously compared against reference values to determine attachment status. This feedback enables the system to distinguish between actual road surface conditions and sensor detachment events, maintaining both continuous monitoring and estimation accuracy.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10585113B2Method for determining detachment of acceleration sensor and apparatus for determining detachment of acceleration sensor

Publication Date: 2020.03.10 BRIDGESTONE CORP

AI summary

A method and an apparatus configured to acquire, as acceleration information, a peak level ak which is a magnitude of a peak on a positive side or a negative side of an acceleration signal in a tire circumferential direction or a tire width direction detected by an acceleration sensor, or a peak interval bk which is a time interval between peaks, or acquire the peak level ak or the peak interval bk of a differential acceleration signal in a tire radial direction obtained by differentiating the acceleration signal in the tire radial direction; calculate ratios Pk, Qk of a difference between the acquired acceleration information ak, bk and average values Ak−1 of the acceleration information to the average values; and determine that the acceleration sensor is detached from the inside of the tire when the calculated ratio Pk, Qk exceeds a preset threshold value Kp, Kq by multiple times successively.