Navigation Data Integrity Control Unit Automotive
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Solution Overview
Problem
Existing methods for determining the integrity of navigation data in automotive vehicle control units during shutdown and wake-up phases are inefficient, leading to potential data loss and inability to distinguish between data recorded in read-only memory, and the method does not allow for quick data recovery during reactivation.
Innovation Solution
A method involving the use of counters and fingerprints to determine the integrity of navigation data by copying data to a reset-safe area of the random access memory during shutdown and then to read-only memory, with subsequent comparison in the wake-up phase to ensure data integrity and recovery from the appropriate memory source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data backup to read-only memory is performed during shutdown phase, then data integrity is improved, but waking response time deteriorates due to the 100ms to 3s backup duration
Solution Approach 1:
The patent applies preliminary action by writing navigation data to the reset safe area at the beginning of the shutdown phase, before the actual backup to read-only memory starts. This preliminary placement ensures that if waking occurs during shutdown, the data is already in a safe location and can be immediately restored, eliminating the need to wait for the read-only memory backup to complete.
2Speed
If waking is triggered during shutdown phase before read-only memory backup completes, then response speed is improved, but data integrity deteriorates due to potential data loss
Solution Approach 1:
The patent uses the reset safe area as an intermediary storage location between random access memory and read-only memory. When waking is triggered during shutdown, the microcontroller checks whether the read-only memory backup is complete by comparing counters. If incomplete, it restores data from the reset safe area intermediary, ensuring data integrity without waiting for the slow read-only memory backup to finish.
3Adaptability or versatility
If multiple restarts occur at high rate, then system adaptability is improved, but data backup reliability deteriorates as data may be permanently lost
Solution Approach 1:
The patent implements beforehand cushioning by maintaining the reset safe area as a permanent backup location that is not cleared during restarts. This creates a safety cushion against data loss in case of rapid successive restarts that would prevent completion of read-only memory backups. The reset safe area preserves data across restart cycles, ensuring that at least one valid copy exists.
4Measurement precision
If existing fingerprint comparison method is used, then data verification capability is improved, but ability to detect incomplete backup deteriorates
Solution Approach 1:
The patent implements feedback by writing counters to both the reset safe area and read-only memory that track the backup progress. The microcontroller compares these counters after waking to determine whether the read-only memory backup is complete. This feedback mechanism provides explicit information about backup status, enabling detection of incomplete backups that the traditional fingerprint method alone cannot identify.
Data Source
AI summary
A method for determining the integrity of navigation data of a control unit of an automotive vehicle, including the steps involving setting two counters to a value strictly above the maximum of the two counters, and, in a waking phase, calculating the fingerprints of the data written to the reset safe area, comparing the counters and determining the integrity of the data when the counters are the same.