Overview
ISO 19380:2019 - Heavy commercial vehicles and buses - Centre of gravity measurements defines standardized test methods to locate a vehicle’s centre of gravity (CG) in all three axes. The document covers measurement of the longitudinal and lateral CG positions in the horizontal plane (using wheel or platform scales) and three accepted methods to estimate vertical CG height: axle lift, tilt-table, and stable pendulum. It applies to heavy commercial vehicles and buses as defined in ISO 3833 (truck/trailer classes above 3.5 t and buses/articulated buses above 5 t; ECE/EC categories M3, N2, N3, O3, O4). Measurements are performed per single vehicle unit.
Key technical topics and requirements
- Scope and applicability: Measurement methods tailored for heavy vehicles and buses; intended for single-unit testing.
- Reference system and variables: Definitions for coordinate axes, variables to be measured for x, y (horizontal plane) and z (vertical) CG positions.
- Measurement of horizontal CG (x, y): Sequential use of wheel or platform scales to compute longitudinal and lateral CG coordinates.
- Vertical CG methods:
- Axle lift method - lifting one axle and measuring load shifts.
- Tilt-table method - controlled roll tilt of a planar platform until wheel lift or critical tilt angle occurs.
- Stable pendulum method - vehicle mounted on a pendulum platform with measurements of equilibrium torque/angle.
- Measuring equipment & test conditions: Requirements for scales, cranes/axle hoists, tilt-tables, pendulums, wheel dummies, ambient/test surface, vehicle loading and fluids.
- Procedures and data presentation: Stepwise test procedures, determination of loaded tyre radius, platform properties, and standardized test reporting formats (annexes for each method).
Practical applications and users
ISO 19380:2019 is used to:
- Support vehicle dynamics modelling and simulation by providing accurate CG coordinates.
- Validate chassis design, suspension tuning and stability systems.
- Inform rollover, handling and braking test design and safety assessments.
- Verify payload distribution, coupling/towing behaviour, and regulatory compliance in design and homologation.
Primary users:
- Vehicle manufacturers and design engineers
- Independent test laboratories and certification bodies
- Regulatory authorities and homologation agencies
- Academic and safety researchers focused on heavy-vehicle dynamics
Related standards
- ISO 3833 - Vehicle categories and definitions (normative for applicability)
- ISO 8855 - Vehicle dynamics vocabulary
- ISO 15037-2 - General conditions for heavy vehicle dynamics tests
Keywords: ISO 19380:2019, centre of gravity, CG measurements, axle lift, tilt-table, stable pendulum, heavy commercial vehicles, buses, vehicle dynamics, vertical CG height, horizontal CG coordinates.