Regulation 79 Consolidated to 03 Series of amendments (Revision
4)Steering Equipment
[TEXT]
[Regulation]
INTRODUCTION
The intention of the Regulation is to establish uniform provisions for the layout and
performance of steering systems fitted to vehicles used on the road. Traditionally the
major requirement has been that the main steering system contains a positive
mechanical link between the steering control, normally the steering wheel, and the road
wheels in order to determine the path of the vehicle. The mechanical link, if amply
dimensioned, has been regarded as not being liable to failure.
Advancing technology, coupled with the wish to improve occupant safety by elimination
of the mechanical steering column, and the production advantages associated with
easier transfer of the steering control between left and right hand drive vehicles, has led
to a review of the traditional approach and the Regulation is now amended to take
account of the new technologies. Accordingly it will now be possible to have steering
systems in which there is not any positive mechanical connection between the steering
control and the road wheels.
Systems whereby the driver remains in primary control of the vehicle but may be helped
by the steering system being influenced by signals initiated on-board the vehicle are
defined as "Advanced Driver Assistance Steering Systems". Such systems can
incorporate an "Automatically Commanded Steering Function", for example, using
passive infrastructure features to assist the driver in keeping the vehicle on an ideal path
(Lane Guidance, Lane Keeping or Heading Control), to assist the driver in manoeuvring
the vehicle at low speed in confined spaces or to assist the driver in coming to rest at a
pre-defined point (Bus Stop Guidance). Advanced Driver Assistance Steering Systems
can also incorporate a "Corrective Steering Function" that, for example, warns the driver
of any deviation from the chosen lane (Lane Departure Warning), corrects the steering
angle to prevent departure from the chosen lane (Lane Departure Avoidance) or corrects
the steering angle of one or more wheels to improve the vehicle’s dynamic behaviour or
stability.
In the case of any Advanced Driver Assistance Steering System, the driver can, at all
times, choose to override the assistance function by deliberate action, for example, to
avoid an unforeseen object in the road.
It is anticipated that future technology will also allow steering to be influenced or
controlled by sensors and signals generated either on or off-board the vehicle. This has
led to several concerns regarding responsibility for the primary control of the vehicle and
the absence of any internationally agreed data transmission protocols with respect to
off-board or external control of steering. Therefore, the Regulation does not permit the
general approval of systems that incorporate functions by which the steering can be
controlled by external signals, for example, transmitted from roadside beacons or active
features embedded into the road surface. Such systems, which do not require the
presence of a driver, have been defined as "Autonomous Steering Systems".
This Regulation also prevents the approval of positive steering of trailers by means of
electrical control from the towing vehicle as there are currently no standards applicable to
this application. It is expected that at some time in the future, ISO 11992 will be amended
to include messages associated with the transmission of steering control.
[R79.01S5-9]
1. SCOPE
1.1. This Regulation applies to the steering equipment of vehicles of categories M, N and O.
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[Reg79R3-10]
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