EV Torque Distribution Using Loss Maps and Speed Thresholds

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Solution Overview

Problem

Existing electric vehicles face challenges in determining an optimal torque distribution between multiple electric machines that minimizes power losses while avoiding negative side-effects such as excessive oversteering and jerk disturbances, which can impact driving comfort and safety.

Innovation Solution

A method that determines torque distribution based on power loss data, torque demand, and speed data, considering thresholds for optimizing energy efficiency, driving comfort, or safety by using a data processing system to calculate and apply optimal torque distributions between electric machines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If optimal torque distribution is determined to minimize power losses, then energy efficiency is improved, but driving comfort and safety may deteriorate due to excessive oversteering and jerk disturbances

Engineering Contradiction:
Improvepower lossesVSAvoiddriving comfort and safety
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system dynamically changes operational parameters (torque distribution, speed, acceleration) based on real-time conditions. By continuously adjusting these parameters within acceptable ranges rather than固定在单一最优值, the system maintains energy efficiency while avoiding extreme torque distributions that cause oversteering and jerk disturbances

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a dynamic control system that adapts torque distribution in real-time based on vehicle speed, acceleration, and power loss maps. This dynamic approach allows the system to respond to changing driving conditions, preventing sudden torque changes that would cause discomfort while maintaining optimal efficiency when conditions permit

Inventive Principle:
Principle #15Dynamics

2Device complexity

If fixed gear is assigned to each machine, then control simplicity is improved, but adaptability to different operating conditions deteriorates

Engineering Contradiction:
Improvecontrol simplicityVSAvoidadaptability to different operating conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system transitions from static fixed-gear assignment to dynamic gear selection based on real-time operating conditions. The control system continuously evaluates vehicle speed, torque demand, and power loss characteristics to determine optimal gear configurations, enabling adaptation to varying driving conditions while maintaining manageable control complexity through systematic decision logic

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4578702A1Method for determining a torque distribution between two or more electric machines of an electric vehicle
Publication Date: 2025.07.02 VOLVO CAR CORP
  • EP4578702A1 patent drawingFigure 1~2
  • EP4578702A1 patent drawingFigure 3~4
  • EP4578702A1 patent drawingFigure 5

AI summary

The disclosure relates to a method (100) for determining a torque distribution between two or more electric machines (12) of an electric vehicle (1) for a total torque demand of the electric vehicle (1), the method (100) comprising: - obtaining power loss data, the power loss data being indicative of power loss saving potentials (4) based on torque distributions between the two or more electric machines (12) for different total torque demands and different speeds of the electric vehicle (1); - obtaining torque demand data indicative of a total torque demand of the electric vehicle (1); - obtaining speed data indicative of a speed of the electric vehicle (1); and - determining the torque distribution between the two or more electric machines (12) based on the obtained power loss data, the obtained torque demand data, and the obtained speed data.