EU Regulation on Emergency Lane Keeping Systems Published
The mandatory fitment of Emergency Lane Keeping Systems (ELKS) is one of the new safety features required by EU Regulation 2019/2144 on "the type approval requirements of motor vehicles and their trailers, and systems, components and separate technical units intended for such vehicles, as regards their general safety and the protection of vehicle occupants and vulnerable road users", more commonly referred to as General Safety Regulation 2 or GSR 2. From July 6, 2022, the fitment of ELKS becomes mandatory for all new types of M1 and N1 category vehicle (i.e. passenger cars, multipurpose passenger vehicles, pick-up trucks and vans) and, from July 7, 2024, the fitment of such systems will become mandatory for all new vehicles falling into those categories. However, delayed introduction dates are permitted for vehicles with hydraulic power assisted steering systems.
To support the mandatory introduction of ELKS, the European Commission have been developing an Implementing Regulation to specify the necessary technical requirements and test procedures for such systems over the past two years. The final version of this Implementing Regulation was published in the Official Journal of the European Union on April 20, 2021 as Implementing Regulation (EU) 2021/646. According to the requirements specified in this new Regulation, Emergency Lane Keeping Systems (ELKS) are actually a combination of two separate systems; a lane departure warning system (LDWS), which warns the driver when a potential lane departure is detected, and a corrective directional control function (CDCF), which automatically adjusts the vehicle's trajectory to correct an inadvertent lane departure.
The key technical requirements applicable to lane departure warning systems (LDWS) can be summarised as follows:
- The system must be active at speeds between 65km/h and 130km/h.
- The system must be able to detect both solid line and dashed lane markings.
- The system must be able to detect lane departures at velocities between 0.1m/s and 0.5m/s.
- The system must provide a warning to the driver, at the latest, when the vehicle has crossed the lane marking by a margin of 0.3m.
- The warning provided by the system must either be:
- A combination of at least two out of visual, acoustic or haptic signals, or
- Either a haptic or acoustic signal which provides an indication of the direction of unintended drift of the vehicle.
The key technical requirements applicable to corrective directional control functions (CDCF) can be summarised as follows:
- The system must be active at speeds between 70km/h and 130km/h.
- The system must be able to detect solid line lane markings.
- The system must be able to detect lane departure at velocities between 0.2m/s and 0.5m/s at vehicle speeds up to 100km/h and at velocities between 0.2m/s and 0.3m/s at vehicles speeds exceeding 100km/h.
- The system must intervene to correct the trajectory of the vehicle, at the latest, when the vehicle has crossed the lane marking by a margin of 0.3m.
- The system intervention to adjust the vehicle’s trajectory may act directly on the steering system or may act on the braking system by braking individual wheels.
- It must be possible for the driver to override the system when it intervenes via steering input.
- Each intervention of the system must be signalled to the driver via a visual warning signal.
- Any interventions which exceed 10 seconds must also be signalled to the driver via an acoustic signal.
- If two interventions occur within 180 seconds of each other, the system must provide an acoustic signal to the driver during the second intervention.
- If further interventions occur within a rolling 180 second interval, further acoustic signals must be provided for each intervention, with each one lasting 10 seconds longer than the previous one.
In addition to specifying test procedures to establish the compliance of the LDWS and CDCF systems with these requirements, (EU) 2021/646 also specifies the following additional requirements for the complete emergency lane keeping system (ELKS):
- Failure warning - Requiring the ELKS to have an integral self-checking capability and specifying how a failure in the ELKS must be notified to the driver.
- System deactivation - Specifying the conditions when deactivation of the ELKS may be permitted, including allowing automatic deactivation of the ELKS when another electronic driver assistance system is in operation, e.g. an electronic stability control system.
- Safety concept - Specifying the documentation that must be compiled and submitted by the vehicle manufacturer to describe the technical details of the system and its operation, and the measures incorporated into the design of the system to ensure its safe operation in all use conditions, including in both fault and non-fault conditions.