Overview
ISO/TR 16250:2013 - Road vehicles: Objective rating metrics for dynamic systems - defines standardized methods to calculate the level of correlation between two non‑ambiguous time‑history signals. It focuses on comparing test measurements and Computer‑Aided Engineering (CAE) simulation outputs in passive vehicle safety (e.g., forces, moments, accelerations, velocities, displacements). The Technical Report evaluates and combines state‑of‑the‑art metrics (CORA, EARTH/EEARTH, model reliability and Bayesian confidence metrics) into an overall ISO rating for objective model validation.
Key Topics and Technical Requirements
- Scope and signals: Applies to non‑ambiguous time‑history signals from dynamic system tests and corresponding numerical simulations; validated for various physical loads.
- CORA metric: Corridor rating (inner/outer corridors), cross‑correlation, phase/size/shape components and weighting-used to quantify waveform overlap and progression.
- EARTH / EEARTH metric: Magnitude, phase and slope (topology) scores with weighting and exponent factors; EEARTH is an enhanced form to improve robustness.
- Model reliability & Bayesian confidence metrics: Statistical measures to assess predictive capability and confidence in CAE models.
- Combined ISO metric: Procedures to compute an overall objective rating from individual metrics (CORA or EEARTH/EEARTH paths).
- Pre‑processing requirements: Guidance on sampling rate, filtering, and interval of evaluation to ensure meaningful comparisons.
- Limitations and validation: Statements on applicable signal types, metric validation boundaries, interpretation of scores, and handling of multiple responses.
- Procedural content: Step‑by‑step procedures, symbols and definitions, and informative case studies (sled tests, child restraint examples).
Practical Applications and Users
ISO/TR 16250:2013 is intended for:
- CAE engineers and validation teams who need objective, repeatable metrics to compare simulation outputs with physical tests.
- Passive safety engineers in OEMs and suppliers validating occupant protection systems and vehicle structures.
- Test laboratories and researchers conducting impact, crash or sled tests and assessing model fidelity.
- Regulatory bodies and quality assurance groups seeking standardized, traceable methods for model assessment.
Benefits include consistent, quantitative model validation decisions, improved model refinement prioritization, and clearer communication of model confidence across development teams.
Related Standards (if applicable)
ISO/TR 16250:2013 complements broader model verification & validation practices developed by organizations referenced in the report (DOE, AIAA, DMSO/DOD, ASME). It was developed under ISO/TC 22 (Road vehicles) to harmonize objective rating approaches used in vehicle safety CAE and testing.