Motor Torque Filtering for Hybrid Vehicle Smoothness

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Solution Overview

Problem

Hybrid electric vehicles face challenges in smooth torque transitions, leading to vehicle jerk and poor driving experiences due to inadequate motor torque filtering, especially in brake energy recovery and over-zero torque conditions, which affect fuel consumption and riding comfort.

Innovation Solution

A motor torque filtering control method that selects appropriate filtering strategies based on current working conditions, using predefined mapping tables and interpolation coefficients to adjust filtering gradients, ensuring smooth transitions and rapid response to regen requests without impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If motor torque filtering is applied to avoid shock and dragging sensation, then riding comfort is improved, but the response speed to regen requests decreases

Engineering Contradiction:
Improveriding comfortVSAvoidresponse speed to regen requests
Core Design Contradiction:
Ease of operationVSSpeed

Solution Approach 1:

The patent applies dynamic filtering gradient adjustment by switching between different filtering strategies (first strategy with gradient calculation based on vehicle speed and torque, second strategy with fixed gradient) depending on operating conditions. This allows the system to optimize the balance between smooth torque transitions and rapid response to regeneration requests in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the filtering parameter (filtering gradient) based on vehicle operating conditions such as speed, torque, and driving mode. By adjusting the filtering gradient dynamically, the system achieves both smooth torque transitions for comfort and adequate response speed for energy recovery.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If motor torque filtering is applied to avoid vehicle jerk, then driving experience is improved, but fuel consumption increases due to slower regen response

Engineering Contradiction:
Improvedriving experienceVSAvoidfuel consumption
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The system dynamically adjusts filtering intensity based on driving conditions, using lighter filtering when rapid response is needed for energy recovery and heavier filtering when smooth transitions are prioritized. This dynamic adaptation optimizes the trade-off between driving comfort and energy efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The filtering parameters are changed according to operating conditions including vehicle speed, torque magnitude, and driving mode, allowing the system to minimize energy loss while maintaining acceptable driving experience across different scenarios.

Inventive Principle:
Principle #35Parameter changes

3Speed

If distributed motor torque is not filtered or filtering effect is poor, then regen request response is fast, but vehicle jerk occurs due to drastic torque change

Engineering Contradiction:
Improveregen request response speedVSAvoidtorque stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent implements a dynamic filtering system that adapts its intensity based on real-time operating conditions. The filtering gradient is calculated or selected to provide adequate torque smoothing without excessive delay, maintaining both response speed and torque stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes filtering parameters based on vehicle speed, torque levels, and driving mode to achieve optimal balance between response speed and torque stability for each operating condition.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4108503B1Motor torque filtering control method and system, and hybrid vehicle
Publication Date: 2024.01.31 ZHEJIANG GEELY HLDG GRP CO LTD
  • EP4108503B1 patent drawingFigure 1~2
  • EP4108503B1 patent drawingFigure 3
  • EP4108503B1 patent drawingFigure 4~5

AI summary

Provided are a motor torque filtering control method and system and a hybrid electric vehicle. The motor torque filtering control method comprises: acquiring a vehicle speed in a current filtering cycle and a motor request torque distributed before filtering, and acquiring a motor output torque after filtering in a previous filtering cycle; determining a maximum filtering velocity Vmax and a minimum filtering velocity Vmin according to the motor output torque and the vehicle speed; determining an interpolation coefficient R according to the motor request torque and the vehicle speed, or according to the motor request torque, the vehicle speed, the maximum filtering velocity Vmax and the minimum filtering velocity Vmin, wherein 0≤R≤1; calculating a first filtering gradient M1 by a formula M1=R∗Vmax+(1-R)∗Vmin; and filtering the motor request torque of the motor according to the first filtering gradient M1. The solution of the present invention can ensure that a vehicle runs smoothly without impact, and improve the riding comfort of a passenger.