Vehicle NVM Wake-Up Validation to Prevent False Diagnostics
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Solution Overview
Problem
In electrified vehicles, unscheduled power-down events, such as a 12V power loss due to crashes, can cause default values to override non-volatile memory (NVM) data, leading to false diagnostics and improper vehicle functions, which results in customer dissatisfaction.
Innovation Solution
A controller, such as a battery pack control module, reads NVM data and writes it to a RAM mirror, maintaining a separate copy for periodic processes. It determines the validity of the wake-up event and, if invalid, writes the read data to the RAM mirror instead of default values, avoiding data overwrites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If default values are written to RAM mirror during wake-up events, then initialization is simplified and faster, but data accuracy deteriorates due to overwriting valid diagnostic information
Solution Approach 1:
The system performs preliminary actions by maintaining a separate copy of NVM data in RAM before wake-up events occur. This pre-prepared copy is then used to restore accurate data after unscheduled power-downs, avoiding the need to rewrite data during wake-up while preventing data loss.
Solution Approach 2:
The patent creates a copy of the NVM data in RAM memory as a mirror image. This copy serves as a backup that can be restored during wake-up events, particularly after invalid power-downs, thereby preserving diagnostic information without requiring slow NVM re-reading.
2Measurement precision
If NVM data is read and written during every wake-up event, then data freshness is improved, but system complexity increases due to additional validation logic
Solution Approach 1:
The patent introduces an intermediary mechanism - a validity flag or indicator - that simplifies the decision-making process. Instead of complex validation logic, the system uses this intermediary marker to distinguish between valid and invalid wake-up events, determining whether NVM data should be restored to RAM.
3Reliability
If a separate copy of NVM data is maintained in RAM, then data recovery after crash events is improved, but memory usage increases
Solution Approach 1:
The system creates a copy of NVM data in RAM memory as a mirror image. This copy serves as a backup that can be restored during wake-up events, particularly after invalid power-downs, thereby preserving diagnostic information without requiring slow NVM re-reading.
Data Source
AI summary
A non-volatile memory (NVM) initialization control method for an electrified vehicle includes providing an NVM configured to store data relating to operation of the electrified vehicle including information relating to a high voltage battery system of the electrified vehicle, detecting a wake-up event of the electrified vehicle and, in response, executing a base software (BSW) that reads the data from the NVM and writes the data to a random-access memory (RAM) mirror, reading the data from the RAM mirror only once and maintain a separate copy of the read data from the NVM for usage by periodic processes during operation of the electrified vehicle, determining whether the wake-up event is a valid wake-up event and, when invalid, executing application software (ASW) configured to write the read data to the RAM mirror instead of default values.