Curative Oscillation Control for Electric Vehicle Transmission

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Solution Overview

Problem

Existing control functions for limiting speed or torque oscillations in electric or hybrid vehicles often fail to attenuate oscillations effectively, leading to vibrations and potential transmission damage, and lack driver intervention options during inappropriate corrections.

Innovation Solution

A method that activates a curative approval function by counting significant oscillations exceeding a predefined threshold, deactivating the function when a certain number of overruns occur, and reactivating it after a reset, using filtration and envelope construction to detect oscillations and manage activation/deactivation smoothly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the curative approval function runs continuously to correct oscillations, then comfort is improved, but transmission elements may suffer wear and damage from excessive vibrations

Engineering Contradiction:
Improvevehicle comfortVSAvoidtransmission wear and damage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the curative approval function's activation state variable rather than static. The function dynamically switches between active and inactive states based on real-time oscillation counting, allowing the system to adapt to changing conditions and prevent transmission damage while maintaining comfort during normal operation.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the curative approval function is deactivated to stop oscillation divergence, then transmission protection is improved, but the function cannot respond to new oscillation conditions

Engineering Contradiction:
Improvetransmission protectionVSAvoidresponse to new oscillation conditions
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent implements discarding and recovering by temporarily deactivating the curative approval function when oscillation thresholds are exceeded, then reactivating it after the count resets. This allows the system to discard the harmful oscillation state, protect the transmission, and subsequently recover the ability to respond to new oscillation conditions when safe.

Inventive Principle:
Principle #34Discarding and recovering

Data Source

PatentEP2943381B1Method for controlling a corrective oscillation-reducing function that limits oscillations of an electric machine
Publication Date: 2016.09.28 PSA AUTOMOBILES SA
  • EP2943381B1 patent drawingFigure 1~2
  • EP2943381B1 patent drawingFigure 3~4

AI summary

A method for controlling a corrective oscillation-reducing function that limits the speed or torque oscillations on transmission elements linking an electric machine (20) to the wheels (22) of an electric or hybrid vehicle, said function correcting the torque setpoint given to this machine in order to limit these oscillations, from speed or torque measurements on the transmission, characterised in that, during the activation of the smoothness function, it counts the number of significant oscillations exceeding a predefined strength threshold within a time limit, and when said threshold has been exceeded a certain number of times, it deactivates the curative smoothness control function.