ISO 17288-1-2011 PDF

Full title and description

Passenger cars — Free-steer behaviour — Part 1: Steering-release open-loop test method. Specifies an open‑loop test procedure to determine the free control stability of a passenger car by measuring the transient behaviour that follows steering release, starting from a steady‑state cornering condition.

Abstract

ISO 17288-1:2011 defines a laboratory/track test method for quantifying a passenger car’s free‑steer behaviour: the transient vehicle response (yaw, lateral acceleration, path deviation) observed after the driver releases the steering while the vehicle is in steady‑state cornering. The procedure establishes instrumentation, initial conditions, test execution and data processing to obtain repeatable measures of free control stability.

General information

• Status: Published (confirmed international standard).
• Publication date: February 2011 (2011-02).
• Publisher: ISO (International Organization for Standardization).
• ICS / categories: 43.100 (Passenger cars; caravans and light trailers).
• Edition / version: Edition 2 (2011).
• Number of pages: 7 (ISO original publication).

Scope

Provides an open‑loop steering‑release test method for assessing free control stability of passenger cars (as defined in ISO 3833). The test starts from a steady‑state cornering condition; the driver releases the steering wheel and the subsequent transient vehicle behaviour is recorded and analysed. The standard focuses on test procedure, instrumentation and data treatment rather than pass/fail criteria.

Key topics and requirements

• Definition of free‑steer behaviour and its relevance to vehicle stability and controllability.
• Test vehicle preparation and instrumentation requirements (yaw rate, lateral acceleration, vehicle speed, steering‑wheel/road wheel angle sensors and data acquisition sampling rates).
• Specification of initial steady‑state cornering condition(s) and how to achieve/verify them prior to steering release.
• Exact steering‑release manoeuvre procedure (driver actions, release timing and allowable driver intervention).
• Data processing and metrics to characterise transient response (decay rates, peak yaw/lateral deviations, time constants, normalisation methods).
• Guidance on test area, environmental conditions and repeatability considerations to ensure comparable results.
• Emphasis that the method is an open‑loop measurement procedure — it provides objective measures for comparison, not prescriptive stability limits.

Typical use and users

Used by passenger‑vehicle manufacturers, vehicle dynamics engineers, OEM test laboratories, tyre and component suppliers, independent test houses and regulatory/assessment bodies to quantify and compare free‑steer stability characteristics across vehicles, variants or development iterations. Also used in research and forensic investigations of handling behaviour.

Related standards

Closely associated documents include: ISO 17288-2:2011 (Part 2 — steering‑pulse open‑loop test method) which complements Part 1 by providing an alternative open‑loop input; ISO 3833 (vehicle type/definitions) cited for vehicle categorization; and other vehicle dynamics test standards such as ISO 4138 (steady‑state circular driving/road‑holding test methods) and related ISO/TC 22/SC 33 publications addressing dynamic stability tests. These standards are commonly referenced together when performing comprehensive vehicle dynamics assessments.

Keywords

Free‑steer behaviour, steering‑release, open‑loop test, passenger car, vehicle dynamics, stability, yaw rate, lateral acceleration, ISO 17288, test procedure, vehicle handling.

FAQ

Q: What is this standard?

A: ISO 17288-1:2011 is an international standard that specifies an open‑loop steering‑release test method to measure the free‑steer (free control) stability of passenger cars.

Q: What does it cover?

A: It covers test preparation, instrumentation, initial steady‑state cornering conditions, the driver release manoeuvre, data acquisition and processing steps needed to characterise the transient vehicle response after steering release. It provides measurement methodology rather than pass/fail criteria.

Q: Who typically uses it?

A: Vehicle manufacturers, vehicle dynamics and safety engineers, test labs, tyre/component suppliers, research organizations and regulatory or assessment bodies that evaluate handling and lateral stability.

Q: Is it current or superseded?

A: The 2011 edition (Edition 2) superseded the 2002 edition. The 2011 text is the current published ISO version; users should check the ISO catalogue or national adoption bodies for the latest status and any subsequent confirmations or revisions.

Q: Is it part of a series?

A: Yes — ISO 17288 is a multi‑part series addressing free‑steer behaviour. Part 1 covers steering‑release open‑loop tests; Part 2 covers steering‑pulse open‑loop tests (ISO 17288‑2:2011). The series sits within ISO/TC 22 vehicle dynamics work.

Q: What are the key keywords?

A: Free‑steer behaviour, steering release, open‑loop, vehicle dynamics, stability, yaw rate, lateral acceleration, ISO 17288‑1.