Vehicular Control Device Wake-Up Stop Circuit for Dark Current Reduction

Solution Overview

Problem

In vehicles with multiple ECUs, a persistent issue is the increased dark current when the ignition is off due to ECUs remaining in an active state due to fixed operation switches, leading to battery exhaustion.

Innovation Solution

A vehicular control device with a wake-up circuit and a wake-up stop circuit that interrupts the wake-up signal after a predetermined time, allowing the control unit to enter a sleep state even if the operation switch is fixed in an on-state, preventing unnecessary CAN communication and reducing consumption current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the operation switch is fixed in an on-state to ensure continuous operation of the electrical component, then the wake-up signal remains at a high level, but the control unit cannot enter sleep state, causing increased dark current consumption

Engineering Contradiction:

Improvecontinuous operation capabilityVSAvoiddark current consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The wake-up stop circuit implements periodic action by automatically interrupting the wake-up signal after a predetermined time period has elapsed since the wake-up instruction. This time-based periodic interruption allows the control unit to enter sleep state even when the operation switch remains fixed in on-state, thereby reducing dark current consumption while maintaining the capability for continuous operation when needed.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The wake-up stop circuit acts as an intermediary between the operation switch and the wake-up circuit. It receives the wake-up signal from the operation switch, processes it through a time-based control mechanism, and selectively transmits or interrupts the signal to the wake-up circuit. This intermediary function enables automatic signal interruption after a predetermined time, resolving the contradiction between continuous operation and energy consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If CAN communication is performed continuously between ECUs to maintain system readiness, then the ECUs remain operational, but consumption current increases leading to battery exhaustion

Engineering Contradiction:

Improvesystem readinessVSAvoidbattery energy

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The wake-up stop circuit implements periodic action by automatically interrupting the wake-up signal after a predetermined time period has elapsed since the wake-up instruction. This time-based periodic interruption allows the control unit to enter sleep state even when the operation switch remains fixed in on-state, thereby reducing dark current consumption while maintaining the capability for continuous operation when needed.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system dynamically transitions between active and sleep states based on the duration of the wake-up signal. The wake-up stop circuit introduces dynamic time-based control, allowing the control unit to adapt its operational state automatically. This dynamic behavior enables the system to balance between maintaining readiness and conserving battery energy by entering sleep state after a predetermined time without continuous CAN communication.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If the wake-up signal is maintained at a high level due to on-state fixation of the operation switch, then the electrical component remains operational, but the control unit cannot enter sleep state, causing increased dark current

Engineering Contradiction:

Improveoperational statusVSAvoiddark current

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The wake-up stop circuit implements periodic action by automatically interrupting the wake-up signal after a predetermined time period has elapsed since the wake-up instruction. This time-based periodic interruption allows the control unit to enter sleep state even when the operation switch remains fixed in on-state, thereby reducing dark current consumption while maintaining the capability for continuous operation when needed.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The wake-up stop circuit acts as an intermediary between the operation switch and the wake-up circuit. It receives the wake-up signal from the operation switch, processes it through a time-based control mechanism, and selectively transmits or interrupts the signal to the wake-up circuit. This intermediary function enables automatic signal interruption after a predetermined time, resolving the contradiction between continuous operation and energy consumption.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10501081B2Vehicular control device, method of controlling vehicular control device, and vehicular control system

Publication Date: 2019.12.10 ASTEMO LTD

AI summary

A vehicular control device includes a control unit that controls an electrical component, a wake-up circuit that wakes up the control unit on the basis of a wake-up signal from a switch for operating the electrical component, and a wake-up stop circuit that interrupts the wake-up signal supplied from the switch to the wake-up circuit after a predetermined length of time has elapsed from a wake-up instruction. The vehicular control device is put to sleep by forcibly interrupting the wake-up signal in the wake-up stop circuit, regardless of the state of the switch after the predetermined length of time has elapsed from the wake-up instruction, and thus it is possible to prevent a wake-up state from being maintained even in a case where the switch is fixed in an on-state.