Dynamic Wheel Imbalance Detection via Shifting Band-Pass Filtering

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Solution Overview

Problem

Current methods for detecting vehicle wheel imbalance are limited, as they typically require dismounting the wheels, using vibration sensors, or are not applicable during vehicle operation, leading to inadequate monitoring of wheel balance issues that can cause vibrations, fatigue, and malfunction in tire pressure monitoring systems.

Innovation Solution

A method that measures wheel rotational speed while the vehicle is moving, applies band-pass filtering with a shifting passband, calculates variance, and compares it to a threshold to detect imbalance, allowing for continuous monitoring without vibration sensors or pressure sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If wheel imbalance detection is performed using conventional methods (dismounted wheels or test benches), then detection accuracy is improved, but vehicle operation is interrupted and productivity decreases

Engineering Contradiction:
Improvewheel imbalance detection accuracyVSAvoidvehicle operation continuity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The detection system transitions from static detection (dismounted wheels on test benches) to dynamic detection (wheels rotating during vehicle operation). The system adapts to varying rotational speeds by adjusting filter parameters in real-time, enabling accurate imbalance detection while the vehicle is in motion, thus maintaining productivity without compromising detection accuracy

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system enables continuous monitoring of wheel balance during vehicle operation rather than requiring periodic removal of wheels for inspection. The detection process runs continuously alongside vehicle operation, allowing real-time identification of imbalance issues without interrupting the vehicle's useful action

Inventive Principle:
Principle #20Continuity of useful action

2Difficulty of detecting and measuring

If vibration sensors are installed on wheels for imbalance detection, then detection capability is improved, but device complexity increases

Engineering Contradiction:
Improvewheel imbalance detection capabilityVSAvoidsensor system complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The system uses the wheel's own rotational speed signal (already generated by the vehicle's motion) as the detection source. Instead of requiring external vibration sensors, the system processes the existing rotational speed data through filtering and variance analysis to detect imbalance, making the wheel essentially self-diagnostic

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces mechanical vibration sensing with signal processing of rotational speed data. By substituting physical vibration measurement with mathematical filtering and statistical analysis of speed signals, the system achieves detection capability without adding mechanical sensor complexity

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

3Device complexity

If rotational speed measurement is used for imbalance detection, then device complexity is reduced, but measurement precision deteriorates due to noise and variability

Engineering Contradiction:
Improvedetection system simplicityVSAvoidrotational speed signal accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

Instead of analyzing the entire rotational speed signal, the system applies band-pass filtering to isolate specific frequency bands corresponding to wheel imbalance characteristics. This selective frequency analysis enhances the precision of imbalance detection by focusing only on relevant signal components while rejecting noise

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system continuously monitors the variance of filtered rotational speed signals and compares it against threshold values. This feedback mechanism allows real-time adjustment and confirmation of imbalance conditions, improving measurement precision through iterative validation rather than relying on a single measurement

Inventive Principle:
Principle #23Feedback

4Productivity

If wheel imbalance is not detected, then vehicle operation continues uninterrupted, but harmful effects increase including vibrations, fatigue, and tire pressure monitoring malfunctions

Engineering Contradiction:
Improvevehicle operation continuityVSAvoidvibrations and mechanical fatigue
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system provides continuous feedback on wheel balance status during vehicle operation. When imbalance is detected through variance analysis of filtered rotational speed signals, the system can alert operators or trigger diagnostic routines, enabling timely intervention before harmful effects such as vibrations and fatigue accumulate

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The detection system rapidly identifies imbalance conditions through real-time signal processing, allowing the vehicle to quickly transition from undetected imbalance to diagnosed condition. This rapid detection minimizes the duration of harmful effects by enabling prompt corrective action

Inventive Principle:
Principle #21Skipping (Rushing through)

Data Source

PatentEP3049786B1Method for detecting an imbalance of a vehicle wheel while the vehicle is rolling
Publication Date: 2018.07.11 RENAULT SA
  • EP3049786B1 patent drawingFigure 1
  • EP3049786B1 patent drawingFigure 2
  • EP3049786B1 patent drawingFigure 3~4

AI summary

The invention relates to a method for detecting the imbalance of a vehicle wheel, wherein a rotational speed (coi) of the wheel is measured while the vehicle is moving, and a filtered value (ωband) is calculated by applying at least one filtering (14) of the band-pass type to the measured value of rotational speed of the wheel. The position of the pass-band of the band-pass filtering (14) is staggered during the rolling of the vehicle according to the rotational speed of the wheel (ω1).