Steering Vibration Factor Estimation for Electric Power Steering

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Solution Overview

Problem

Existing methods for analyzing and suppressing vibrations in electric power steering systems require significant time and effort, and adjusting controller settings without identifying vibration factors can be ineffective.

Innovation Solution

An input/output device that estimates vibration factors by extracting feature amounts from response data using a vibration factor estimation unit, reducing the need for manual analysis and enabling efficient controller settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If users manually analyze vibration factors each time vibration occurs, then vibration suppression can be achieved, but it takes a significant amount of time and effort

Engineering Contradiction:
Improvevibration suppression effectivenessVSAvoidtime and effort for analysis
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system automatically estimates vibration factors by itself without requiring user intervention. The vibration factor estimation unit processes response data, extracts feature amounts, and identifies vibration factors autonomously, making the system serve itself in analyzing vibration causes.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical analysis with an automated estimation system that uses response data and feature amount extraction algorithms to identify vibration factors, substituting human effort with an automated computational system.

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

2Reliability

If controller settings are adjusted by trial and error without specifying vibration factors, then some vibration suppression may be achieved, but it is not a fundamental measure and requires significant time

Engineering Contradiction:
Improvevibration suppression effectivenessVSAvoidadjustment efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary estimation of vibration factors before adjusting controller settings. By first identifying the vibration factor through feature amount extraction and then determining appropriate controller settings based on the estimation result, the system avoids trial-and-error approaches.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses response data from the electric power steering device as feedback to continuously estimate vibration factors and adjust controller settings accordingly, creating a closed-loop system that adapts based on actual vibration conditions.

Inventive Principle:
Principle #23Feedback

3Reliability

If mechanical characteristics, frequency characteristics, or noise characteristics are identified and controller is set accordingly, then vibration can be suppressed, but vibration or noise may still occur due to identification errors or unintended disturbances

Engineering Contradiction:
Improvevibration suppression effectivenessVSAvoididentification accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system dynamically estimates vibration factors during steering operations rather than using fixed pre-identified characteristics. The vibration factor estimation unit processes real-time response data and extracts feature amounts adaptively, allowing the system to respond to changing vibration conditions and unexpected disturbances.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4516634B1Input/output device and steering measurement device
Publication Date: 2026.03.18 MITSUBISHI ELECTRIC CORP
  • EP4516634B1 patent drawingFigure 1
  • EP4516634B1 patent drawingFigure 2~3
  • EP4516634B1 patent drawingFigure 4

AI summary

An input/output device (3) includes: a vibration factor estimation unit (32) configured to be connected for communication to a control device for controlling a rotating machine provided in an electric power steering device provided in a vehicle to generate a steering assist force for a steering, to acquire, during a steering operation of the steering, response data indicating a response to a steering operation of the electric power steering device detected by the control device, to extract a feature amount related to a vibration or a noise generated during the steering operation of the steering from the response data, and to estimate a vibration factor candidate, which is a candidate for a vibration factor, based on the feature amount; and an output unit (33) configured to output the vibration factor candidate.