Battery knowledge · High-voltage and functional safety
Diagnostic coverage
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. [1]
- Relationship
- coverage = λ_detected / λ_total
Example
Calculate a simplified coverage fraction
If relevant dangerous failure rates total 100 units and 90 of those units are detected by the stated diagnostics, this simplified coverage is 90%. Counting failure modes without weighting their rates gives a different quantity.
Explore the graph
Coverage is a rate-weighted fraction, not a count of checks.
Detecting 90 FIT out of 100 FIT gives 90% coverage. 1 FIT = 1 failure per billion operating hours.
Diagnostic coverage = λ_detected / λ_total
Illustrative model. Detected and total rates must describe the same population, failure modes and operating basis. Independent assessment is needed to justify either rate.
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.