Virtual Gear Ratio Torque Control for Variable Vehicle Loads

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Solution Overview

Problem

Conventional vehicles with fixed final gear ratios cannot optimize fuel efficiency across varying operational conditions, leading to increased fuel consumption and environmental impact due to mismatched torque demands.

Innovation Solution

A computer system determines a virtual total gear ratio based on operational parameters like vehicle speed, acceleration, weight, and road topography to simulate optimal torque management, adjusting motor control for improved fuel efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed final gear ratio is used in the powertrain system, then the vehicle structure remains simple and reliable, but the fuel efficiency cannot be optimized across varying operational conditions

Engineering Contradiction:
Improvefuel efficiency optimizationVSAvoidpowertrain system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the gear ratio concept through software simulation. Instead of physically changing gear ratios with multiple transmissions, the system calculates a virtual total gear ratio that replicates the effect of different physical gear ratios on motor torque, allowing flexible adaptation without additional mechanical complexity

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the parameter being controlled from fixed physical gear ratio to variable virtual gear ratio. By modifying the virtual total gear ratio parameter based on operational conditions (vehicle speed, acceleration, load, topography), the system achieves adaptability while keeping the physical powertrain structure simple

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the physical total gear ratio is changed to optimize torque for different conditions, then fuel efficiency improves, but the mechanical complexity and cost of the powertrain system increases

Engineering Contradiction:
Improvefuel consumptionVSAvoidpowertrain mechanical structure
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical gear ratio adjustment system with a software-based torque management system. Instead of physically changing gear ratios through complex transmissions and differentials, the system uses processing circuitry to calculate and apply virtual gear ratio adjustments to motor torque control, eliminating the need for additional mechanical components

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The virtual total gear ratio serves as a software copy of the physical gear ratio concept, replicating its torque-modifying effect through calculation rather than mechanical transmission, thereby achieving the same fuel efficiency benefits without the associated mechanical complexity

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If multiple physical gear ratios are provided for different operating conditions, then the vehicle can be optimized for various terrains and loads, but the system reliability and simplicity decrease

Engineering Contradiction:
Improveoperational condition coverageVSAvoidpowertrain system reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

Instead of using multiple physical gear ratios that require additional mechanical components and potential failure points, the patent creates a virtual copy of the gear ratio function through software calculation. The virtual total gear ratio is computed based on operational parameters, providing the same adaptability across different terrains and loads while maintaining a simpler, more reliable single-stage physical transmission system

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4450850B1Computer system and method for controlling torque provided by a motor
Publication Date: 2025.11.12 VOLVO TRUCK CORP
  • EP4450850B1 patent drawingFigure 1
  • EP4450850B1 patent drawingFigure 2~3
  • EP4450850B1 patent drawingFigure 4~6

AI summary

A computer system (700) comprising processing circuitry (702) for controlling a torque provided by a motor (20) of a powertrain system (15) of a vehicle (10), the powertrain system (15) being configured to provide a physical total gear ratio (PGR), wherein the processing circuitry (702) is configured to: - determine a virtual total gear ratio (VGR) for the powertrain system (15) based on one or more operational parameters (OP) of the vehicle (10), and - cause control of the torque provided by the motor (20) based on the virtual total gear ratio (VGR).