Battery knowledge · High-voltage and functional safety
Hardware safety metrics
The ISO 26262 numbers showing that random hardware failures are under control. The single-point and latent fault metrics are the shares of failures that safety mechanisms cover — at least 99% and 90% for ASIL D — and PMHF is the residual rate of violating a safety goal, below 10⁻⁸ per hour (10 FIT) for ASIL D. [1]
- Abbreviation
- SPFM, LFM, PMHF
- Also called
- single-point fault metric, latent fault metric, probabilistic metric for random hardware failures, hardware architectural metrics
Example
High-voltage and functional safety: an example situation
Normal-operation current limits do not demonstrate correct contactor behavior under a welded-contact or sensor fault.
Read Hardware safety metrics alongside Diagnostic coverage in this context. The fraction of a component’s failure rate that a safety mechanism detects or controls. ISO 26262 treats coverage from about 60% as low, from 90% as medium and from 99% as high; comparing two independent measurements of the same cell voltage typically earns high coverage, while a simple plausibility check earns much less.
Use in Lemonergy
Relate protection to faults, detection and response.
This is a reference concept. No executable Lemonergy block has been verified for this term.
References & further reading
Technical references
- ISO 26262-1:2018 — Road vehicles — Functional safety — Part 1: Vocabulary
International Organization for Standardization · 2018
Technical reference · Scope and terminology of automotive electrical/electronic functional safety. The catalogue is not the full standard.