EV Powertrain Speed Recommendation Using Lumped Efficiency Maps

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Solution Overview

Problem

Existing electric vehicles with multiple motor devices face inefficiencies in energy consumption due to suboptimal speed and torque distribution, which can be improved by determining recommended vehicle speeds and torque allocations based on power efficiency and road topography.

Innovation Solution

A computer-implemented method that obtains data on motor system efficiency, road topography, and resistance forces to recommend optimal vehicle speed and torque distribution, using a lumped efficiency map to guide drivers towards more energy-efficient driving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple motor devices are used in the powertrain configuration, then the vehicle can achieve better performance and versatility, but energy consumption increases due to suboptimal speed and torque distribution

Engineering Contradiction:

Improvepowertrain configuration flexibilityVSAvoidenergy consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically changes operating parameters (vehicle speed, torque distribution, power split ratio) based on road topography and efficiency maps to optimize energy consumption while maintaining multiple motor device configuration flexibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic adjustment of torque distribution and power split ratios between multiple motor devices based on real-time conditions and pre-calculated efficiency maps, transforming a static multi-motor system into a dynamically optimized energy-efficient system

Inventive Principle:

Principle #15Dynamics

2Productivity

If vehicle speed is increased to improve travel time, then productivity increases, but power consumption increases due to resistance forces

Engineering Contradiction:

Improvetravel speedVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The system performs preliminary calculations of optimal vehicle speeds based on upcoming road topography segments before the vehicle reaches them, allowing proactive speed adjustments that minimize power consumption while maintaining productivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The efficiency maps pre-calculate and store optimal speed-torque combinations, allowing the control system to quickly skip through calculation iterations and directly apply optimized parameters during real-time operation

Inventive Principle:

Principle #21Skipping (Rushing through)

Data Source

PatentEP4659990A1Energy efficient speed recommendation based on lumped powertrain efficiency for electric vehicles

Publication Date: 2025.12.10 VOLVO CAR CORP

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AI summary

A computer-implemented method for improved energy usage for a vehicle comprising a motor system comprising a plurality of motor devices, the method comprising obtaining first data indicative of power efficiency of the motor system at different vehicle speeds, obtaining second data indicative of a topography of an upcoming road segment to be travelled by the vehicle, determining third data indicative of power efficiency for the topography of the upcoming road segment at different vehicle speeds based on the first data and the second data, and determining a recommended vehicle speed based on a resistance force acting on the vehicle and the third data.