EV Drive Torque Damping Control for Vibration-Responsive Acceleration

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Solution Overview

Problem

Existing drive systems for electric vehicles face challenges in reducing vibration-induced unintended acceleration and deceleration, as conventional filtering methods fail to distinguish between intentional and unintentional accelerator pedal actuation, leading to jerky drivetrain responsiveness.

Innovation Solution

A method and system that determine an error between a torque command signal and a damped torque command signal, reducing damping when the error exceeds a threshold based on vehicle resonant frequency, using lookup tables to control damping rates, thereby differentiating between intentional and unintentional pedal movements and smoothing torque application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional filtering methods are applied to torque command signals, then vibration-induced unintended acceleration is reduced, but intentional driver inputs are also dampened causing jerky drivetrain responsiveness

Engineering Contradiction:
Improvevibration-induced unintended accelerationVSAvoiddrivetrain responsiveness
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The damping factor is dynamically adjusted based on the error magnitude between filtered and unfiltered torque commands. When error exceeds threshold, damping is reduced to allow rapid response to intentional inputs; when error is small, damping is maintained to filter vibrations. This dynamic adaptation resolves the contradiction between filtering effectiveness and responsiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the damping parameter conditionally based on error threshold comparison. The damping factor transitions between high and low states depending on whether the error between filtered and unfiltered torque commands exceeds a predetermined threshold, allowing the system to adapt its filtering strength to current operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high damping is applied to torque command signal, then unintended pedal actuation is reduced, but rapid response to intentional driver inputs is delayed

Engineering Contradiction:
Improveunintended pedal actuation reductionVSAvoidresponse speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The damping level transitions dynamically between high and low states based on real-time error monitoring. When the error between filtered and unfiltered torque commands exceeds the threshold, the system switches to low damping for rapid response; otherwise, high damping is maintained for reliability. This dynamic switching resolves the speed-reliability contradiction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system preemptively reduces damping when error exceeds threshold, preparing the system for potential intentional driver inputs before they fully manifest. This preliminary anti-action prevents delayed response while maintaining reliability during normal filtered operation.

Inventive Principle:
Principle #9Preliminary anti-action

3Speed

If damping is reduced to improve response speed, then intentional driver inputs are responded to rapidly, but vibration-induced torque fluctuations increase

Engineering Contradiction:
Improveresponse speedVSAvoidtorque fluctuations
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The damping parameter is changed conditionally based on error threshold comparison. The system maintains high damping (filtering) when error is small to reduce torque fluctuations, and switches to low damping when error exceeds threshold to improve response speed. This conditional parameter change resolves the contradiction between smoothing and responsiveness.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4342717A1Drive system and method of control
Publication Date: 2024.03.27 ARVINMERITOR TECHNOLOGY LLC
  • EP4342717A1 patent drawingFigure 1
  • EP4342717A1 patent drawingFigure 2~3
  • EP4342717A1 patent drawing

AI summary

A drive system and method of control. The method includes reducing damping of a damped torque command signal when an error between a torque command signal and the damped torque command signal exceeds a threshold amount. Torque is provided with a torque source of the drive system based on the damped torque command signal.