Tire Sensor Distance Correction for Low-Speed Odometer Accuracy

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Solution Overview

Problem

Existing tire sensor modules face errors in measuring travel distance, especially at low vehicle speeds and when deactivated, leading to inaccurate kilometer recordings, particularly in city traffic scenarios.

Innovation Solution

A method and measuring arrangement that utilize a correction function to adjust the radial acceleration measurements, with a higher correction factor applied at low radial accelerations to compensate for errors, and asymptotically approaching 1 at higher accelerations, taking into account tire radius, sensor resolution, and application scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radial acceleration measurement is used to determine travel distance, then the odometer function is enabled, but measurement accuracy deteriorates at low speeds and during sensor deactivation

Engineering Contradiction:
Improvetravel distance measurement accuracyVSAvoidmeasurement reliability at low speeds
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by introducing a speed-dependent correction factor that modifies the distance calculation based on the current speed regime. At low speeds, a larger correction factor compensates for the limited resolution of radial acceleration measurements, while at higher speeds the correction factor approaches unity. This dynamic parameter adjustment resolves the contradiction by adapting the measurement accuracy to the operating conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the direct mechanical relationship between radial acceleration and distance calculation with a corrected computational model. Instead of using the raw formula distance = rolling_speed × time, the system substitutes a corrected approach that incorporates the correction factor derived from speed and radial acceleration characteristics, thereby improving reliability without adding mechanical components.

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

2Use of energy by moving object

If the tire sensor module is deactivated in parking mode, then battery consumption is reduced, but distance traveled during low-speed movement is not recorded

Engineering Contradiction:
Improvebattery consumptionVSAvoiddistance information during deactivation
Core Design Contradiction:
Use of energy by moving objectVSLoss of information

Solution Approach 1:

The patent applies preliminary action by proactively compensating for the distance information that would be lost during sensor deactivation. The correction factor is calculated and applied in advance to account for the period when the sensor was deactivated, ensuring that the total distance is accurately recorded even though the sensor was not actively measuring during low-speed movement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effect of deactivation (loss of distance information) into a benefit by using the correction factor to statistically compensate for the missing data. The system acknowledges the deactivation period and applies a corrective measure that transforms the information loss into an accurate distance calculation, maintaining battery efficiency while preserving measurement integrity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If radial acceleration measurement resolution is limited, then sensor complexity is reduced, but distance determination accuracy deteriorates at low speeds

Engineering Contradiction:
Improvesensor complexityVSAvoiddistance measurement precision at low speeds
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary element - the correction factor - that mediates between the limited sensor resolution and the required measurement precision. This correction factor, derived from speed and radial acceleration characteristics, acts as a computational bridge that enhances the effective resolution of the measurements without requiring a more complex sensor.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting the correction factor based on the operating conditions. At low speeds where measurement precision is critical, a larger correction factor is applied to compensate for the limited sensor resolution. This parameter adaptation allows the system to maintain high measurement precision while using a simple, low-resolution sensor.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4147886B1Method for determining a route of a vehicle tyre, measuring assembly and vehicle
Publication Date: 2024.06.05 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP4147886B1 patent drawingFigure 1~3

AI summary

The invention relates to a method for determining the distance traveled (W) of a vehicle tire, wherein the vehicle tire has a tire sensor module (10) with a sensor unit (3) for measuring a radial acceleration (aR), comprising the following steps: - generating sensor signals (S3) characterizing the radial acceleration (aR) of the vehicle tire over a time interval (dt); - determining a distance interval (Wi) traveled by the vehicle tire within the respective time interval (dt); and - determining the distance traveled (W) of the vehicle tire from the determined distance interval (Wi), wherein a correction factor (K) is taken into account when determining the at least one distance interval (Wi) to correct the determined distance interval (Wi).According to the invention, the correction factor (K) is determined from a correction function (F) which assigns a correction factor (K) to the radial acceleration (aR) measured by the sensor unit (3) or to a quantity dependent thereon, wherein the correction function (F) is defined such that the distance interval (Wi) is corrected more strongly by the respective assigned correction factor (K) at a low radial acceleration (aR) than at a high radial acceleration (aR).