Dynamic Speed Threshold for Vehicle Start-Stop Energy Savings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional start-stop systems for motor vehicles face challenges in determining when to switch off the drive motor efficiently, as they often rely on fixed speed thresholds that do not account for varying environmental conditions, leading to unnecessary energy consumption.

Innovation Solution

A method where the speed threshold for switching off the drive motor is dynamically adjusted based on current environmental information, including speed limits from navigation systems, detected traffic signs, and wireless traffic information, allowing the system to react to specific driving and traffic situations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed speed threshold is used for switching off the drive motor, then the control system is simple, but the energy efficiency deteriorates due to unnecessary engine stops

Engineering Contradiction:
Improvecontrol system complexityVSAvoidenergy consumption
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent applies the dynamics principle by making the speed threshold variable instead of fixed. The control device dynamically adjusts the speed threshold based on current driving conditions, traffic situations, and environmental factors. This allows the system to adapt to changing conditions and avoid unnecessary engine stops, thereby reducing energy consumption while maintaining reasonable control complexity through automated threshold adjustment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the speed threshold parameter based on various input conditions. The control device changes the speed threshold parameter dynamically according to driving dynamics, traffic information, and environmental data. This parameter adaptation enables the system to optimize energy efficiency by switching off the drive motor only when appropriate conditions are met, rather than using a static threshold.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the drive motor is switched off frequently to save energy, then energy consumption is reduced, but the reliability of power supply deteriorates

Engineering Contradiction:
Improveenergy consumptionVSAvoidpower supply reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies feedback by continuously monitoring driving conditions, traffic situations, and system state to determine whether to switch off the drive motor. The control device receives feedback from various sensors and systems (driving dynamics sensor, navigation system, traffic information) and uses this feedback to make informed decisions about engine shutdown. This feedback mechanism ensures that the drive motor is switched off only when it is safe and appropriate to do so, maintaining power supply reliability while achieving energy savings.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If environmental information is considered for adjusting the speed threshold, then the adaptability to driving situations is improved, but the device complexity increases

Engineering Contradiction:
Improveadaptability to driving situationsVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements universality by making the control device multi-functional. The control device not only manages the drive motor switching but also processes environmental information, driving dynamics data, navigation information, and traffic data. By integrating these multiple functions into a single control device, the system achieves high adaptability to various driving situations while minimizing the increase in overall system complexity through functional integration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3332114B1Method for operating a start-stop system and a motor vehicle
Publication Date: 2019.10.16 AUDI AG
  • EP3332114B1 patent drawingFigure 1
  • EP3332114B1 patent drawingFigure 2

AI summary

The invention relates to a method for operating a start-stop system (5) of a motor vehicle (1), a drive motor being switched off when the speed falls below a speed threshold. Said speed threshold is determined depending on at least one environment-related information.