Steering Column Noise Detection via Microphone Positioning

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for detecting abnormal noise in steering systems face challenges due to low signal-to-noise ratios and difficulties in mounting sensors, leading to inaccurate inspections and space constraints.

Innovation Solution

A method involving a microphone positioned to face the end portion of the column shaft in a steering system, which measures sound and generates an abnormal noise detection signal, combined with a vibration exciter to enhance detection sensitivity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a microphone is positioned at the lower part of the electric power steering device to detect abnormal noise, then the detection can be performed, but the mounting space is insufficient and the detected noise does not always coincide with the actual abnormal noise heard in the vehicle

Engineering Contradiction:

Improveabnormal noise detection accuracyVSAvoidmounting space

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent transitions from detecting noise at the lower part of the steering device (vertical dimension) to detecting noise at the end portion of the column shaft on the steering wheel side (horizontal dimension near the steering wheel). This spatial repositioning in another dimension provides adequate mounting space while capturing the actual abnormal noise source more accurately.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent replaces the mechanical detection approach at the lower steering device with an acoustic detection approach using a microphone positioned near the column shaft end. This substitution allows for non-contact or minimal-contact detection that does not require complex mounting structures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a microphone is positioned at the ear position of the test driver to detect abnormal noise, then the detection can be performed, but it is difficult to extract only the component of abnormal noise due to the steering system from dominant tire road noise and engine noise

Engineering Contradiction:

Improveabnormal noise detection accuracyVSAvoidsignal-to-noise ratio

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent extracts the abnormal noise detection function from the general vehicle interior noise environment and relocates it to the specific location near the column shaft end. This extraction isolates the steering system noise source from dominant background noises like tire road noise and engine noise, enabling clear detection of the target signal.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces the column shaft end portion as an intermediary location between the steering system noise source and the microphone. This intermediary position serves as an optimal acoustic measurement point that captures steering system abnormalities while being spatially separated from other noise sources.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This approach allows for precise detection of abnormal noise with improved signal-to-noise ratios, enabling reliable evaluation of steering systems without the need for mounting sensors at the lower part of the vehicle.

Implementation Method 1

measuring a sound from an end portion of the column shaft on a steering wheel-side by using a microphone arranged to face the end portion of the column shaft

Methodology Applied

Scientific EffectSound measurement: Sound

Implementation Method 2

a frame configured to support the steering system and having a vibration exciter configured to apply a vibration

Methodology Applied

Scientific EffectVibration: Vibration

Data Source

PatentUS10634647B2Abnormal noise detection method of steering system and evaluation device of steering system

Publication Date: 2020.04.28 NSK LTD

AI summary

An abnormal noise detection method of a steering system is configured to detect an abnormal noise from the steering system. The steering system includes a column shaft configured to rotatably support a steering wheel and is configured to steer a wheel in response to rotations of the column shaft. The method includes measuring a sound from an end portion of the column shaft on a steering wheel-side by using a microphone arranged to face the end portion of the column shaft, and generating an abnormal noise detection signal due to the steering system from a sound signal to be output from the microphone.