Overview
ISO/TS 21002:2021 - Road vehicles: Multidimensional measurement and coordinate systems definition provides a unified method for measuring and reporting 2D/3D positions from multidimensional sensors used in crash test dummies (ATDs). The Technical Specification defines measurement coordinate systems, a protocol to determine sensor offsets to the chosen coordinate system, and the method to process sensor spherical-coordinate data to compute the 3D position of a dummy feature in a local orthogonal coordinate system.
Key topics and requirements
- Measurement coordinate systems: Definitions of global and local orthogonal coordinate systems fixed to dummy reference features (e.g., thoracic spine).
- Sensor configuration: Covers assemblies combining one distance sensor and one or two angle sensors arranged as a (rotating) spherical coordinate system.
- Zero-position protocol: Procedures and acceptance limits for establishing a sensor “zero-position” using a zero-position fixture. The fixture must be reproducible and is considered adequately accurate when dimensional tolerance stack-ups are within ±0.3 mm.
- Offset and orientation handling: Definitions and procedures for offset angle, orientation angle (e.g., left/right/frontal = -90°, 0°, +90°), reference angle, and angle sensor polarity to ensure consistent sign conventions (SAE right-hand rule).
- Sensor calibration and verification: Steps for sensor calibration, zero-position data collection, calculations, and verification using Data Acquisition System (DAS) parameters.
- Coordinate transformation: Method to convert sensor outputs from spherical coordinates to the defined local orthogonal coordinate system and process results for dummy feature positions.
- Supporting material: Informative annexes with orthogonal coordinate examples, zero-position fixtures and collection examples, mathematical background, applicable sensors, DAQ workflow suggestions, ISO MME code examples, and expected outputs.
Practical applications
- Ensuring consistent, repeatable position measurement of ATD features (ribs, abdomen, thorax) during crash tests.
- Standardising data processing in test labs to convert raw sensor spherical data into meaningful 3D positions in dummy-fixed coordinates.
- Guiding sensor manufacturers, DAQ integrators, and ATD designers on mounting, offset compensation, polarity and orientation conventions.
- Supporting post-processing software verification and regulatory or research reporting where traceable, reproducible kinematic position data are required.
Who should use this standard
- Automotive safety engineers and crash test laboratories
- ATD (dummy) manufacturers and instrumentation suppliers
- Sensor designers and integrators for multidimensional measurement systems
- Data acquisition and post‑processing software developers
- Regulatory bodies and researchers working on occupant protection and impact testing
Related standards
- References and terminology link to ISO MME coding and ISO/TS 13499 (ISO MME Code DC for Distance are noted within the document).
