Mild Hybrid State-of-Charge Control via Predictive Thresholds

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Solution Overview

Problem

Mild hybrid vehicles face inefficiencies in energy storage management, leading to suboptimal fuel consumption and emissions, as existing strategies either reserve too much energy, leading to inefficient fuel conversion or not enough, resulting in insufficient energy for vehicle features like start-stop and freewheel engine functions.

Innovation Solution

The procedure optimally selects the target charging status area by dividing the energy storage device's usable area into reserves for energy recovery and consumption, determining upper and lower threshold values based on predicted driving conditions and vehicle parameters, ensuring efficient energy use and minimizing fuel consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If energy is reserved in the energy storage device to ensure sufficient supply for start-stop and freewheel functions, then reliability of vehicle features is improved, but fuel consumption increases due to inefficient fuel conversion

Engineering Contradiction:
Improvereliability of start-stop and freewheel functionsVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of the target state-of-charge range based on predicted driving conditions. The control device adapts the energy reservation strategy in real-time, expanding or contracting the target SOC range according to forecasted energy demands from start-stop and freewheel functions, thereby optimizing the balance between reliability and fuel consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses predictive algorithms to forecast future energy requirements before they occur. By determining the target state-of-charge range in advance based on predicted driving conditions, the system proactively prepares the energy storage device to meet future demands, avoiding both over-reservation and under-reservation of energy

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the target state of charge range is set too high, then energy supply reliability is improved, but fuel efficiency deteriorates due to excessive energy reserve

Engineering Contradiction:
Improveenergy supply reliabilityVSAvoidfuel efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent dynamically changes the target state-of-charge parameter based on predicted driving conditions. The control device adjusts the target SOC range boundaries (upper and lower limits) according to forecasted energy demands, transforming the static parameter into a dynamic one that adapts to varying operational requirements, thereby optimizing both reliability and fuel efficiency

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If the target state of charge range is set too low, then fuel consumption is reduced, but energy supply sufficiency deteriorates for vehicle features

Engineering Contradiction:
Improvefuel consumptionVSAvoidenergy supply sufficiency
Core Design Contradiction:
Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The patent implements a feedback mechanism where the control device continuously monitors actual energy consumption patterns and compares them with predictions. Based on this feedback, the system refines its predictive models and adjusts the target state-of-charge range accordingly, ensuring that energy supply sufficiency is maintained while minimizing fuel consumption

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3448713B1Method for controlling an energy storage device of a mild hybrid motor vehicle and state-of-charge control device for a mild hybrid motor vehicle
Publication Date: 2022.10.12 AUDI AG
  • EP3448713B1 patent drawingFigure 1
  • EP3448713B1 patent drawingFigure 2
  • EP3448713B1 patent drawingFigure 3

AI summary

The invention relates to a method for controlling an energy storage device (10) of a mild hybrid motor vehicle, wherein the energy storage device (10) has an overall capacity, wherein a state-of-charge control device (32) of the energy storage device (10) sets a state of charge of the energy storage device (10) between an upper threshold value (oSW) and a lower threshold value (uSW) for a target state-of-charge range (18) of the energy storage device (10), wherein during at least one journey at least one charging process (34) and one discharging process (36) are monitored with respect to quantities of energy which are exchanged with the energy storage device (10) and quantities of energy which are to be expected with a predefinable probability for future charging processes and discharging processes are determined, and wherein the upper threshold value (oSW) and the lower threshold value (uSW) for the target state-of-charge range (18) of the energy storage device (10) are defined on the basis of the determinations in step b). The invention also relates to a corresponding state-of-charge control device (32) for a mild hybrid motor vehicle.