Vehicle Start-Stop Control via Indirect Battery Estimation

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Solution Overview

Problem

Existing methods for managing the start-stop function in vehicles with internal combustion engines require additional electronic components and sensors to determine the state of charge of the vehicle battery, leading to increased costs and complexity.

Innovation Solution

A method that suppresses the switch to a standby state if shutdown bans are detected based on parameters such as the current usage status and history of the electrical energy storage device, coolant temperature, and power consumption, allowing for indirect estimation of the battery's state of charge without precise measurement, thereby reducing the need for complex electronics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional electronic components and sensors are used to determine the state of charge of the vehicle battery, then the reliability of the start-stop function is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvereliability of start-stop functionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the battery state determination from direct measurement and replaces it with indirect estimation using existing sensor data (coolant temperature, power consumption, usage history). This removes the need for additional battery sensors while maintaining sufficient reliability for the start-stop function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The control unit uses the vehicle's existing sensors and data (coolant temperature, power consumption, usage history) to estimate battery state itself, without requiring external battery monitoring components. The system serves its own monitoring needs using resources already available.

Inventive Principle:
Principle #25Self-service

2Reliability

If additional electronic components and sensors are used to determine the state of charge of the vehicle battery, then the reliability of the start-stop function is improved, but the manufacturing cost increases

Engineering Contradiction:
Improvereliability of start-stop functionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the need for expensive additional battery monitoring sensors and components by using indirect estimation methods, thereby reducing manufacturing costs while maintaining adequate reliability for the start-stop function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses low-cost indirect estimation based on readily available data (coolant temperature, power consumption) rather than expensive precision battery sensors, accepting good enough accuracy to reduce overall system cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If indirect estimation of battery state of charge is used instead of precise measurement, then the device complexity is reduced, but the measurement precision deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision of battery state of charge
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies partial measurement precision - using indirect estimation sufficient for the start-stop function's needs rather than precise battery state measurement. The estimation accuracy is adequate for determining whether to enable or disable the start-stop function, without requiring exact battery charge levels.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3004626B1Method for operating a vehicle with combustion engine with a start-stop function
Publication Date: 2024.10.09 VOLKSWAGEN AG
  • EP3004626B1 patent drawingFigure 1
  • EP3004626B1 patent drawingFigure 2
  • EP3004626B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a vehicle (1) comprising an internal combustion engine (12) having a start-stop function, via which the vehicle (1) can be automatically switched between a normal operating state with running internal combustion engine (12) and a readiness state with internal combustion engine (12) deactivated, having the steps: examining (400) the presence of at least one deactivation prohibition and, in the case of the presence of at least one deactivation prohibition, inhibiting (500) the switching to the readiness state, wherein at least one deactivation prohibition considers at least one of the following parameters: the current usage status of an electrical energy store (14) of the vehicle (1) and/or the progression of the usage status of an electrical energy store (14) of the vehicle (1) over a predetermined period of time, preferably over the last travel made by the vehicle (1).