Electric Axle Assembly Adaptive Vibration Cancellation

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Solution Overview

Problem

Electric axle assemblies in motor vehicles produce mechanical vibrations that fall within the audible spectrum, resulting in noise amplification at specific points, necessitating a method to reduce or cancel these vibrations.

Innovation Solution

An electric axle assembly incorporating a noise canceling device with a transducer and control unit that detects vibrations using accelerometers or inertial measurement units, and an adaptive model to compute a correction input to minimize vibrations by optimizing the control signal for the electric machine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If electric machine operation is maintained, then power delivery to wheels is achieved, but mechanical vibrations are produced that fall within audible spectrum causing noise

Engineering Contradiction:
Improvepower deliveryVSAvoidnoise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The control unit computes a correction input that generates vibrations opposite in phase to the detected harmful vibrations, thereby canceling them before they propagate through the axle assembly. This preliminary anti-action is applied continuously through the adaptive model that processes transducer signals in real-time

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The transducer detects vibrations at critical points of the axle assembly and feeds this information back to the control unit. The control unit processes this feedback signal through an adaptive model to generate appropriate correction inputs, creating a closed-loop control system that continuously reduces noise while maintaining power delivery

Inventive Principle:
Principle #23Feedback

2Object-generated harmful factors

If traditional vibration damping methods are used, then some noise reduction is achieved, but device complexity increases and adaptability to varying vibration frequencies is limited

Engineering Contradiction:
Improvenoise reductionVSAvoidcomplexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The system uses the electric machine's own control infrastructure to generate correction inputs, leveraging existing components (control unit, power electronics) to create the anti-vibration signal. This self-service approach avoids adding separate complex damping mechanisms while achieving noise reduction

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The adaptive model dynamically adjusts the correction input parameters based on real-time vibration characteristics detected by the transducer. This allows the system to adapt to varying vibration frequencies and amplitudes without requiring multiple fixed-frequency damping devices, maintaining simplicity while achieving broad-spectrum noise reduction

Inventive Principle:
Principle #15Dynamics

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

The solution effectively attenuates or nullifies the noise-causing vibrations at critical points, reducing the overall noise disturbance experienced by the vehicle's driver through adaptive noise reduction.

Implementation Method 1

a transducer (8) configured to detect a variable representative of one or more parameters identifying a vibration caused by the operation of the motor (6)

Methodology Applied
Scientific EffectVibration detection: Vibration

Implementation Method 2

determining one or more variable parameters of an adaptive model (101) configured to compute a correction input (102) to be superposed to the control input (91) to update the control input, thereby correcting the operation of the motor (6)

Methodology Applied
Scientific EffectSignal processing and adaptive control: Feedback

Data Source

PatentEP4427966A1Electric axle assembly for a vehicle with a noise canceling device
Publication Date: 2024.09.11 FERRARI SPA
  • EP4427966A1 patent drawingFigure 1
  • EP4427966A1 patent drawingFigure 2
  • EP4427966A1 patent drawingFigure 3

AI summary

An electric axle assembly (5) for a motor vehicle (1) includes an electric machine (6) suitable for operating as a motor, an axle (7) for transmitting a power delivered by the electric machine (6) to wheels (4) of the motor vehicle (1), a transducer (8) configured to detect an error variable (e) representative of one or more parameters identifying a first vibration caused by an operation as a motor of the electric machine (6) controlled by a control input, and a control unit (9) configured to acquire the error variable (e) detected by the transducer (8), determine one or more variable parameters of an adaptive model (101) to compute a correction input (102) to be superposed to the control input to update the control input, determine the correction input (102) using the adaptive model (101) defined with the determined variable parameters, and control the electric machine (6) with the updated control input by superposing the correction input (102) to the control input.