ECU Soak Timer Diagnostics Using Stored Clock Time
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic control units struggle to accurately diagnose abnormalities in soak timers when the power switch is in an off-state, leading to potential missed abnormalities if the soak timer operates abnormally.
Innovation Solution
An electronic control unit with a nonvolatile storage portion that continues to supply power to the soak timer regardless of the power switch state, allowing it to count time and activate the control portion at fixed intervals, enabling the detection of abnormality by calculating time differences between stored and acquired time information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the power switch is turned off to save energy, then energy consumption is reduced, but the ability to diagnose soak timer abnormalities is lost
Solution Approach 1:
The power supply system is segmented into two paths: the main power switch controls the control portion while a separate always-on power supply maintains the clock device and nonvolatile storage portion. This segmentation allows the system to enter low-power mode while preserving critical diagnostic functions through the independently powered components.
Solution Approach 2:
Time information is preliminarily stored in the nonvolatile storage portion before the power switch is turned off. This preliminary action ensures that diagnostic data is preserved even when the main system is powered down, enabling post-power-off abnormality detection when the system wakes up.
2Loss of energy
If the power switch is turned off to reduce power consumption, then power consumption is reduced, but time measurement accuracy cannot be verified
Solution Approach 1:
The clock device serves as an intermediary time reference that continues operating independently of the main power switch. It provides a reliable time baseline against which the soak timer's accuracy can be compared after the system wakes up, enabling verification of time measurement accuracy without continuous power consumption.
Solution Approach 2:
The system implements feedback by comparing the soak timer value with the time information from the always-on clock device after waking up. This feedback mechanism verifies whether the soak timer measured time accurately during the powered-off period, allowing the system to detect abnormalities in time measurement without continuous power consumption.
3Loss of energy
If the control portion stops processing when the power switch is off, then energy consumption is reduced, but abnormality detection during off-state is impossible
Solution Approach 1:
The system creates a copy of time information in the nonvolatile storage portion before entering low-power mode. This copied data serves as a reference that can be compared against the soak timer value after waking up, enabling abnormality detection without requiring the control portion to remain active during the off-state.
Solution Approach 2:
The clock device and nonvolatile storage portion perform self-service by maintaining operation independently of the main power switch. They automatically preserve time information and enable diagnostic functions without requiring active control portion intervention, allowing the system to detect abnormalities passively after waking up.
Data Source
AI summary
An electronic control unit includes a control portion and a soak timer. The control portion acquires first time information of a clock device when a power switch is turned off and stores the first time information in a nonvolatile storage portion. The control portion acquires second time information of the clock device when the soak timer activates the control portion or when the control portion receives an activation request. The control portion calculates a first time difference between the second time information and the first time information stored in the nonvolatile storage portion and determines an abnormality of the soak timer based a difference between the first time difference and the soak timer value of the soak timer.