UN R79 — Supplement 8 to the 04 series of amendments

New paragraphs 2.12. to 2.17. define “Electrical Storage Device (ESD)”, “Energy Management System” and “Electrical supply”. They also define the “performance” and the “state” of an electrical storage device, and the “effect of ageing”. The performance is the ability to provide power (W) and quantity of energy (Wh) when fully charged; the state is that ability at the time. Electrical storage devices connected in series and/or parallel are considered as one electrical storage device within this Regulation. An electrical supply is a device, for example a battery, REESS, generator or fuel-cell, that supplies electrical power to the steering system's electrical storage device(s).

Paragraph 5.3.3.3. now also covers a failure of the electrical supply of the control transmission, not only of its energy source. Paragraph 5.3.3.6. may be used instead where the energy transmission, or a part of it, shares the control transmission's energy source or electrical supply. Under paragraph 5.3.1.8., a full power steering system that satisfies paragraph 5.3.3.6. is considered to have sufficient priority as specified in paragraphs 5.3.1.4. and 5.3.1.5. Paragraph 5.3.3.6.1. gives two conditions, depending on whether the failure affects the ability of the braking system to provide the service braking performance. If it does not, the vehicle must reach 10 km/h or less, or standstill; if it does, the vehicle must reach standstill. Paragraph 5.3.3.6.2. requires this before the energy level is too low for a further lane change, unless the failure leads to loss of propulsion.

Under paragraph 5.3.3.6.3., energy is deemed sufficient if 18 lane changes (M1, N1) or 9 (M2, M3, N2, N3) are possible within 90 s. They are driven at 20 km/h (+/- 2 km/h), alternately left and right, with at least 3 meters of lateral movement. The deceleration demand to reach the condition must not exceed 2 m/s², or up to 4 m/s² only where needed for paragraphs 5.3.3.6.2. and 5.3.3.6.3. The 4 m/s² case applies in specific conditions specified by the vehicle manufacturer and assessed as per Annex 6. Any automatic deceleration must start no earlier than 60 seconds after failure detection, unless the conditions of paragraphs 5.3.3.6.2. and/or 5.3.3.6.4. are met before. There must be a warning on the immediacy of the need to stop, with a dynamic indication of when automatic deceleration is expected to begin.

When the alternative to paragraph 5.3.3.3. is used, there must be an energy management system for the electrical storage device(s). It must be capable of continuously assessing the electrical storage device(s), to determine their ability to deliver the needed power to the steering transmission. If the assessment is not complete at switch-on, a red warning signal must be active until the safe status of the storage device(s) is confirmed. At type approval, the manufacturer must describe how the system determines the safe status, including after maintenance. The Technical Service must check the accuracy of the system under all reasonably foreseeable operating conditions, by reviewing the manufacturer's documentation and by tests. If a failure of the system or an input channel prevents the assessment, a red visual warning and an audible signal must be activated.

The red warning signal of paragraph 5.4.2.1.1. now has a condition: a single additional failure could result in a complete loss of steering function. New paragraph 5.4.2.1.5. requires warning signals where an energy management system as per paragraph 5.3.3.6.7. is installed. With such a system, a yellow warning must be displayed no later than when ageing makes the storage device(s) performance insufficient for paragraph 5.3.3.6.3. This warning must come with information to the driver, for example an extra telltale or text message, that the storage device(s) require a maintenance check. A yellow warning is also due no later than when the storage device's state is insufficient for more than 60 seconds to fulfil paragraph 5.3.3.6.3. A red warning must also be displayed when the state of the ESD(s) is not sufficient for at least half the values in paragraph 5.3.3.6.3.

In paragraph 5.3.1.1., “equivalent characteristics” of a material now has an example: “similar strength and fatigue life attributes”. If the manufacturer's safety concept prevents the 25 “figure of eight” manoeuvres, the manufacturer and the Technical Service must agree how to check the requirement. This procedure must be recorded in the test report and included in the type-approval documentation. If the safety concept also includes automatic braking to reduce the vehicle speed, the deceleration demand must not exceed 2 m/s². Any automatic deceleration demand must start no earlier than 60 seconds after failure detection. If another system, for example AEBS or ACC, controls the longitudinal movement, the vehicle may decelerate at a higher value or earlier.

Paragraph 5.6.4.2.1. now sets the default off mode “at the initiation of the powertrain” instead of “at the initiation of each new engine start/run cycle”. A new engine start (or run cycle) performed automatically does not count as an “initiation of the powertrain” anywhere in this Regulation. A new footnote refers to Mutual Resolution No. 2 (M.R.2), document ECE/TRANS/WP.29/1121, for the definition. Paragraph 5.6.4.8.3. now uses “initiation of the powertrain” in place of “new engine start/run cycle (other than when performed automatically …)”. In Annex 8, the title of paragraph 3.5.7. is now “Initiation of the powertrain test” instead of “Engine start/run cycle test”. The Annex 8 test steps also now say “initiation of the powertrain”, and in two steps the driver initiates “a lane change procedure and manoeuvre”.