Steering Filter Suppresses Head Resonance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing vehicle steering systems do not adequately address vibrations of the occupant's head caused by autonomous steering operations, leading to discomfort and potential motion sickness, as they fail to consider the resonance frequencies induced by steering maneuvers.

Innovation Solution

A steering apparatus with a filtering processor that reduces or eliminates specific frequency components from the steering input waveform, specifically targeting frequencies between 1 to 5 Hz, particularly around 3 Hz, to suppress head vibrations by integrating an occupant behavior detection unit and an autonomous driving control unit to adjust the steering control schedule.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If autonomous steering control is implemented without frequency filtering, then steering responsiveness and automation performance are improved, but head vibration and occupant discomfort increase due to resonance frequencies

Engineering Contradiction:

Improveautonomous steering controlVSAvoidhead vibration

Core Design Contradiction:

Extent of automationVSObject-affected harmful factors

Solution Approach 1:

The harmful frequency components (1-5 Hz range) are extracted and removed from the steering input waveform through filtering processing. The filtering processor specifically targets and eliminates the frequency bands that cause head resonance, separating the useful steering control signals from the harmful vibrational components.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention identifies the resonance frequency characteristics of head vibration and uses this knowledge beneficially by designing a filter that specifically targets these frequencies. The harmful resonance phenomenon is converted into useful information for designing the filtering characteristics, transforming the problem into a solution.

Inventive Principle:

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

2Object-affected harmful factors

If steering input is filtered to reduce head vibration, then ride comfort is improved, but steering responsiveness may be reduced

Engineering Contradiction:

Improvehead vibrationVSAvoidsteering responsiveness

Core Design Contradiction:

Object-affected harmful factorsVSSpeed

Solution Approach 1:

The filtering is applied locally to specific frequency bands (1-5 Hz) rather than uniformly across all frequencies. This allows the system to maintain high responsiveness for steering commands outside this range while selectively attenuating only the problematic frequency components that cause head vibration.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The filter applies partial attenuation only to the specific frequency range causing head vibration, rather than completely blocking all steering inputs or filtering all frequencies. This partial action maintains overall steering responsiveness while sufficiently reducing the harmful vibrational effects.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11618498B2Steering device

Publication Date: 2023.04.04 SUBARU CORP

AI summary

A steering apparatus includes an actuator and an actuator controller. The actuator is configured to generate an output for turning a steerable wheel of a vehicle. The actuator controller is configured to control the actuator in accordance with a steering input. The actuator controller includes a filtering processor configured to perform filtering processing for reducing or cutting a component in a predetermined frequency band from the steering input, and the actuator controller is configured to control the actuator in accordance with the steering input after the filtering processing.