Vehicular Power Supply Control for Automated Driving

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Solution Overview

Problem

Existing vehicle power supply systems face challenges in minimizing charging delays and ensuring electric power for automated driving, especially when the electric generator and second storage device are disconnected, leading to inconveniences and potential safety issues during automated driving modes.

Innovation Solution

A method for controlling a vehicle power supply system that connects the electric generator and lithium-ion battery to the power supply even when the charge ratio of the lead-acid battery is below a prescribed level if automated driving is requested, and connects them only after the lead-acid battery is fully charged if automated driving is not requested, using a controller to manage the relay and ensure timely charging and power availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the electric generator and second storage device are disconnected during charging of the first storage device, then the first storage device can be charged prioritarily, but the electric power required for automated driving cannot be ensured when requested

Engineering Contradiction:
Improvecharging speed of first storage deviceVSAvoidpower supply reliability for automated driving
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the connection state of the relay based on real-time detection of automated driving requests. When automated driving is requested, the relay connects the second storage device to the power supply system even if charging is in progress. When not requested, the relay maintains disconnection to prioritize charging. This dynamic adaptation resolves the contradiction between charging speed and power supply reliability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the electric generator and second storage device are connected when the charge ratio is low, then power availability is improved, but charging delay increases

Engineering Contradiction:
Improvepower supply availabilityVSAvoidcharging time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The control device continuously monitors the charge ratio of the first storage device and the state of automated driving requests. Based on this feedback, it intelligently decides whether to connect the second storage device. This feedback mechanism ensures that the system only connects the second storage device when absolutely necessary (automated driving requested), thereby minimizing charging delays while ensuring power availability when needed.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If automated driving is enabled with insufficient charge, then driver convenience is improved, but system safety may be compromised

Engineering Contradiction:
Improveautomated driving accessibilityVSAvoidpower supply safety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary detection of automated driving requests before enabling automated driving mode. When a request is detected, the control device proactively connects the second storage device to ensure sufficient power supply before automated driving commences. This preliminary action guarantees that power supply safety is established before the automated driving function is activated, resolving the contradiction between accessibility and safety.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3533668B1Vehicular power supply system control method and vehicular power supply system
Publication Date: 2021.01.06 NISSAN MOTOR CO LTD
  • EP3533668B1 patent drawingFigure 1~2
  • EP3533668B1 patent drawingFigure 3~4

AI summary

In a case where a driver has requested automated driving during charging of a lead-acid battery 4 in a state in which a generator 2 and a lithium-ion battery 5 are disconnected, the generator 2 and the lithium-ion battery 5 are electrically connected even when a charge ratio of the lead-acid battery 4 is less than a prescribed percentage. In a case where the driver has not requested automated driving, the generator 2 and the lithium-ion battery 5 are electrically connected after the charge ratio of the lead-acid battery 4 has reached the prescribed percentage.