Vehicle Control Device for Battery Charging Rate Optimization

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Solution Overview

Problem

The degradation of battery performance in vehicles is accelerated by repeated charging and discharging, particularly when a large amount of electricity is discharged, leading to reduced battery lifespan.

Innovation Solution

A vehicle control device that selectively switches between maintenance and high-voltage power generation modes based on the electrical load of auxiliaries, maintaining a higher charging rate when the load is high and adjusting target values for the charging rate based on ambient temperature and cumulative service period to minimize battery discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the battery is repeatedly charged and discharged to power auxiliaries, then the auxiliaries can be driven, but the battery performance degrades faster

Engineering Contradiction:
Improveauxiliary operationVSAvoidbattery performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the charging rate parameter dynamically based on auxiliary load conditions. When auxiliary load is high, the charging rate is increased to maintain higher SOC, reducing discharge depth. When auxiliary load is low, the charging rate is maintained at a lower level. This parameter adjustment resolves the contradiction by optimizing charging behavior to minimize battery degradation while ensuring auxiliary operation capability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the charging rate is maintained at a high target value, then the battery SOC is maintained higher reducing discharge depth, but the power generation device operates at higher load increasing fuel consumption

Engineering Contradiction:
Improvebattery SOCVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of the charging rate target value based on real-time auxiliary load detection. The control unit switches between different target values (first target value for high load, second target value for low load) according to auxiliary operation conditions. This dynamic approach resolves the contradiction by maintaining high SOC only when necessary for auxiliary support, reducing unnecessary power generation and fuel consumption during low-load periods.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the voltage of generated electricity is increased to raise charging rate, then the battery charges faster, but the power generation device operates at higher load

Engineering Contradiction:
Improvecharging rateVSAvoidpower generation device load
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent applies partial action by increasing the charging rate only when necessary (during high auxiliary load periods) rather than maintaining maximum charging rate continuously. The control unit selectively activates high-voltage power generation mode only when auxiliary load exceeds a threshold, allowing the power generation device to operate at higher load only when needed, thus resolving the contradiction between charging productivity and power device load.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4044395A1Vehicle control device
Publication Date: 2022.08.17 TOYOTA JIDOSHA KK
  • EP4044395A1 patent drawingFigure 1
  • EP4044395A1 patent drawingFigure 2
  • EP4044395A1 patent drawingFigure 3

AI summary

A control device is applied to a vehicle having a power generation device, a battery, and auxiliaries, and includes: a power generation mode selection unit that, when an electrical load of the auxiliaries is lower than a threshold value, selects a maintenance mode in which a charging rate of the battery is maintained at a first target value, and when the electrical load is not lower than the threshold value, selects a high-voltage mode in which the voltage of electricity generated is maintained at a higher voltage than in the maintenance mode; and a power generation control unit that, when the charging rate upon switching from the high-voltage mode to the maintenance mode is not lower than a second target value that is higher than the first target value, controls the power generation device so as to maintain the charging rate in the maintenance mode at the second target value.